Title of Invention

VAPORIZING APPARATUS OF LNG AS FUEL FOR A NATURAL GAS FIRING GAS TURBINE COMBINED CYCLE POWER STATION

Abstract

To provide an LNG vaporizing apparatus for an NG firing gas turbine combined cycle power station which is able to generate NG quickly in the amount required following load of the power station without water in the facilities being frozen and is excellent in safety and economy. Construction: With a heat source water which is a cooling water to be heated by cooling a gas turbine intake air at an intake air cooler 20, LNG is vaporized via an incombustible heating medium A at a heating medium evaporator 1 and LNG vaporizers 3 and 4, and a heating medium evaporator 12 and an LNG vaporizer 11. According to a requirement, a cooling water used for cooling the power station machinery and equipment 31 is introduced into heating medium evaporators 12 and 1 through an intel of an internal cooling water cooler 39 to be used as a heat source water.

Full Text

BACKGROUND OF THE INVENTION: Field of the Invention: The present invention relates to a vaporizing apparatus of LNG (liquefied natural gas) as fuel for a natural gas firing gas turbine combined cycle power s:a:::r., and more particularly, to an apparatus in which LNG ir. the amount required in a power station is vaporized by use cf hsat obtained by cooling gas turbine intake air or by use of heat obtained by cooling machinery and equipment of the power station as well as output of the gas turbine is enhanced bv cooling the gas turbine intake air by making use of cold heat of LNG. Description of the Prior Art: As for a power station using LNG as fuel in recent years, a gas turbine combined cycle power stat ion in which a gas turbine and a steam turbine are combinedly used is becoming a main tendency. But, in the gas turbine combined cycle power generation facilities, due to a fact that the gas turbine intake air flow rate is volumetric flow rate constant, there is a feature that the mass flow rate of the intake air becomes less as the atmospheric air temperature becomes higher so that the output of g^s turbine is lowered, and there is a problem that the power generation capacity becomes lower in the summer season when the power consumption becomes higher. In order to cope with this problem, there is a means that gas turbine intake air is cooled by making use of a low temperature LNG as well as LNG is vaporized bv making use of heat obtained by cooling the intake air, as shown in Fig. 3, which is disclosed, for example, by the Japanese laid-open patent application No, Hei. 1 (1989 } -1422 19. The main point thereof is, as shown in F19, 3, that a heat accumulator 4 is disposed between an LNG vaporizer 3 and a gas turbine intake air cooler 8, and a first heating medium circulation line is disposed between the LNG vaporizer 3 and the heat accumulator 4 as well as a second heating medium circulation line is disposed between the heat accumulator 4 and the intake air cooler 8, and at the first heating medium circulation line, vaporization of LNG and cooling of a heat accumulating agent 4a in the heat accumulator are carried out, and at the second heating medium c irculation line, the gas turbine intake air is cooled. In this conventional means, as a heat source for LNG vaporization depends only on the heat obtained by cooling the gas turbine intake air, there is a problem that generation amount of vaporized natural gas (NG) and temperature thereof are influenced by the atmospheric air condition and yet, in case of the winter time etc. when there is no need of cooling the gas turbine intake air, such heat source for LNG vaporization is unavailable and a separate LNG vaporizer to "_:se the sea water etc. as heat source is required. In an LNG vaporizer to use the sea water as heat source, there are such shortcomings, as widely known, as follows: (1) As a large arnoiin- of sea water is required as heat source for LNG vaporization, large capacity sea water supply facilities such as sea water intakes, sea water intake pumps, etc. are required and construction of LNG vaporization facilities becomes complicated. (2) At the portion in the water of the sea water supply facilities, there occurs easily a problem of marine living things sticking, material corrosion, etc., which causes complicated and lengthened maintenance work of the LNG vaporization facilities. (3) As the sea water discharged into the sea after used as heat source for LNG vaporization is of a low temperature, there is considered any influence given on the marine ecosystem, which becomes a restriction in selecting a location of LNG vaporization facilities. Further, as a conventional apparatus to vaporize and heat LNG by use of sea water or warm water as a heat source fluid, an apparatus as shown in Fig. 4 is disclosed by the Japanese published patent No. Sho 61(1986)-24634. The main point thereof is, as shown in Fig. 4, that, within an intermediate heating medium type indirect heat exchanger 1 containing an intermediate heating medium la, the intermediate heating medium la is heated and vaporized by a heat source fluid supplied from a conduit 4 into a tube nest in said heat exchanger 1 and discharged from a conduit 5, and LNG supplied from a conduit 6 into a tube nest 7 contained within the heat exchanger 1 is heated by said vaporized intermediate heating medium. The vapor of intermediate heating medium is condensed to become liquid by the heat exchange with LNG and drops to the lower liquid phase portion to repeat to be vapored again. The LNG heated at the heat exchanger 1 is supplied into a multitubular heat exchanger 2 to be further heated by a heat source fluid supplied from a conduit 3 to a temperature appropriate for use and is discharged as a vapored NG from a conduit 9. In the apparatus according to said conventional method, there are shortcomings as follows: (1) In the multitubular heat exchanger 2, as a method to make direct heat exchange between LNG and heat source fluid without an intermediate heating medium is employed. there is a large possibility of the combustible LNG leaking into the heat source fluid line. The reason for this is that while an operation pressure of LNG in this kind of LNG vaporizing apparatus is usually 20 to 50 kg/cm G, the operation pressure of the heat source fluid is as low as 2 less than 10 kg/cm G, and even if a small defect like a pinhole occurs within the heat exchanger 2, a large amount of LNG leaks into the heat source fluid line. Especially if a warm water of power station is used as a heat source fluid and LNG leaks into this warm water line, then the combustible gas diffuses within the power station to cause problems in the power station safety. (2) As a displacement heat exchange is made between LNG and heat source fluid which freezes at a temperature near to 0°C, there is always a possibility of the heat source fluid freezing within the heat exchanger 2. If a freezing occurs within the heat exchanger 2, it takes a long time for ice melting and the LNG vaporising operation must be stopped during the ice melting operation. Further, if ice is generated, if not a complete freezing, there might occur errosions due to seceding ice pieces to damage the heat exchanger 2, which increases a possibility of LNG leaking into the heat source fluid line. In this conventional method, even if the heat exchanger 1 is so des igned that LNG is heated enough to the temperature not to cause an ice generation in the heat exchanger 2, in case of load changes of LNG or occurring of flow rate changes of heat source fluid, etc., there is still a possibility of freezing. Especially, in a multitubular heat exchanger, biased flows are apt tc occur at the fluid flowing in the tube nest and, if the tubes are of types to make the flow velocity of the fluid slower, ice tends to be easily generated. SUMMARY OF THE INVENTION: It is therefore s~ cfcjer. cf the present invention to provide an LNG vaporizing apparatus which is able at any time of season to vaporize LNG as fuel for a natural gas firing gas turbine combined cycle power station at least in the amount required in the power station, to cool the intake air of gas turbine by use of cold heat of LNG and to prevent lowering of power generation capacity of the power station in the summer season etc. and yet is excellent in safety and economy. In order to attain this object, it is necessary to solve following themes: (i) For securing safety of the power sta tion, a countermeasure not to leak a combustible gas outside of the line and a means to be able to detect easily even a very small amount of leakage are provided. (ii) A gas turbine intake air can be cooled by making use of cold heat of LNG, and heat obtained by cooling the gas turbine intake air is available as an LNG vaporizing heat source. (iii) Under every operational condition of the power station facilities, enough heat source is available inexpensively for providing heat necessary for vaporizing all the LNG necessitated by the power station and that heat source can be used at any time as an auxiliary heat source for the heat obtained by cooling the gas turbine intake air. (iv) Power used for operation of the LNG vaporization apparatus and a new heat source like sream are minimized. (v) In the summer season when the gas turbine intake air is cooled, a function to enhance cooling effect of the gas turbine intake air is provided. (vi) Causes to obstruct a normal operation of the LNG vaporizing apparatus, such as freezing of heat source fluid, can be excluded. (vii) Following load changes of the power station facilities, all the necessitated amount of LNG can be vaporized. (Viii) Temperature of the vapored NG is more than 0°C for safety purpose of the power station facilities. As means to solve said themes, the inventors here disclose vaporizing apparatuses of LNG as fuel for a natural gas firing gas turbine combined cycle power station as shown in the following [1] to [6]: [1] A vaporizing apparatus of LNG as fuel for a natural gas firing gas turbine combined cycle power station _, comprising an LNG vaporizer to heat LNG by heating medium vapor via a metal wall as well as to cool and condense said heating medium vapor; a heating medium evaporator to heat and evaporate by water a heating medium liquid cooled and condensed at said LNG vaporizer to generate said heating medium vapor as well as to cool said wsierr an intake air cooler to cool a gas turbine intake air f;r ~ natural gas firing gas turbine combined cycle power s-aticn by said water cooled by said heating medium evapcra tor; an internal cooling water cooler to cool water for cooling machinery and equipment at said power station by the sea water; a conduit to connect a water outlet of an internal cooling water circulation pump to a water inlet of said internal cooling water cooler, said internal cooling water circulation pump supplying the water after used for cooling said machinery and equipment at the power station to said internal cooling water cooler; a conduit to connect said water outlet of the internal cooling water circulation pump to said machinery and equipment at the power station by by-passing said internal cooling water cooler; a conduit to connect a water outlet of said intake air cooler to a water inlet of said heating medium evaporator; a conduit to connect the water outlet of said internal cooling water circulation pump to the water inlet of said heating medium evaporator; a conduit to connect a water outlet of said heating medium evaporator to a water inlet of said intake air cooler; and a conduit to connect at least one of the water outlet of said heating medium evaporator and the water outlet of said intake air cooler to at least one of the water inlet and the water outlet of said internal cooling water cooler. [2] A vaporizing apparatus cf LNG as fuel for a natural gas firing gas turbine combined cycle power station as mentioned in [1] above, characterized i- that said heating medium is 1,2,2,2-Tetrafluoroethane (HFC-134a). [3] A vaporizing apparatus cf LNG as fuel for a natural gas firing gas turbine combined cycle power station as mentioned in [1] or [2] above, characterized in comprising an internal cooling water temperature regulating flow control valve provided to at least one of the conduit to connect the water outlet of said internal cooling water circulation pump to the water inlet of said internal cooling water cooler and the conduit to connect the water outlet of said internal cooling water circulation pump to said machinery and equipment in the power station by by-passing said internal cooling water cooler; a temperature detecting meter to detect a temperature of water to cool said machinery and equipment at the power station; and a means to regulate the opening of said internal cooling water temperature regulating flow control valve based on a detected value of said temperature detecting meter. [4] A vaporizing apparatus of LNG as fuel for a natural gas firing gas turbine combined cycle power station as mentioned in [1], [2] or [3] above, characterized in comprising a heat ing medium evaporator supply water temperature regulating flow control valve provided to at least one of the conduit tc connect the water outlet of said intake air cooler to the water inlet [5] A vaporizing apparatus of LNG as fuel for a natural gas firing gas turbine combined cycle power station as mentioned in [1], [2], [3] or [4] above, characterized in comprising a first heating medium evaporator contained in a heating medium liquid phase of a first heating medium evaporator body, said first heating medium evaporator body having a heating medium vapor phase in its upper portion and said heating medium liquid phase in its lower portion; a first LNG vaporizer and a second LNG vaporizer disposed at a higher position than the installation position of said first heating medium evaporator and contained in a body, said body being connected of its upper portion by a conduit to said heating medium vapor phase in said first heating medium evaporator body and of its lower portion by a conduit to said heating medium liquid phase of said first heating medium evaporator body; a third LNG vaporizer contained in a heat ir.g .Tedium vapor phase in the upper portion of a body enclosing a heating medium; a second heating medium evaporator contained in a heating med ium liquid phase in the lower portion of said body enclosing said heating medium; a conduit to connect an LNG outlet of said first LNG vaporizer to an LNG inlet of said second LNG vaporizer; a conduit to connect an LNG outlet of said second LNG vaporizer to an LNG inlet of said third LNG vaporizer; a conduit to connect a water inlet of said heating medium evaporator to a water outlet of said intake air cooler and to the water outlet of said internal cooling water circulation pump; a conduit to connect a water outlet of said second heating medium evaporator to a water inlet of said first heat ing medium evaporator; ana a conduit to connect a water outlet of said first heat ing medium evaporator to a water inlet of said intake air cooler. [6] A vaporizing apparatus of LNG as fuel for a natural gas firing gas turbine combined cycle power station as mentioned in [5] above, characterized in compris ing a water supply amount control means consisting of a pressure detecting and regulating meter to detect a pressure of said first heating medium evaporator and give a control signal, a water flow signal selector to take an output sicr.al of said pressure detecting and regulating meter and a demand signal of wazer supply amount and give the smaller signal out of them as a set signal of the water" supply amount, a water flow detector to detect a flow rate of water supplied to said first heating medium evaporator, a water flow regulating meter to take a detected signal of said water flow detector and an output signal of said water flow signal selector and give a water flow control signal and a water supply amount control valve to control water supply to said first heating medium evaporator based on an output signal of said water flow regulating meter; and an LNG supply amount control means consisting of a pressure detecting and regulating meter to detect a pressure of said first heating medium evaporator and give a control s ignal, an LNG flow signal selector to take an output signal of said pressure detecting an regulating meter and a demand signal of LNG supply amount and give the smaller signal out of them as a set signal of the LNG supply amount, an LNG flow detector to detect a flow rate of LNG supplied to said first LNG vaporizer, an LNG flow regulating meter to take a detected signal of said LNG flow detector and an output signal of said LNG flow signal selector and give an LNG flow control signal and an LNG flow control valve disposed at the LNG inlet of said first LNG vaporizer and controlled by an output signal of said LNG flow regulating meter. According to the present invention, following functions are attained: 1) In the solving means [1] above, as LNG is heated and vapored via a metal wall by a hearing medium heated and evaporated by water via a metal wall, there occurs no leakage of LKG into the water c ireflation line. Even if a defect like a pinhole etc. occurs at the metal wall partitioning the heating medium and the LNG, LNG leaks into the heating medium, which is easily detected by a usual process instrument. Further, as the turbine intake air is cooled by water cooled by LNG via the heating medium, even if the atmospheric air temperature is high, lowering of gas turbine output can be prevented. And as said water heated by the gas turbine intake air is used for heating the heat ing medium, the heat obtained by cooling the gas turbine intake air is used indirectly for heating and vaporizing LNG. Further, the warm water after used for cooling machinery and equipment at a power station can be used for heating said heating medium and yet the generated heat at the power station machinery and equipment can be utilized as much as required. This means that the heat source as so far was ted can be utilized as heat source to heat and vaporize LNG as much as required. Moreover, if less heat is generated at the power station machinery and equipment, as said water cooled by LNG, being supplied to the water inlet of the internal cooling water coder to cool water (internal water) to cool said machinery and equipment by the sea water, is heated by the sea water, the heat held by the sea water can be utilized for heating and vaporizing LNG and heat source for heating and vaporizing LNG can be ensured as much as required under every operational condition of the power station. If much heat is generated at the power station machinery and equipment, as said water of low temperature cooled by LNG is supplied to the water outlet of said internal cooling water cooler, the pumping power of the sea water supplied to said internal cooling water cooler can be reduced. 2 ) In the solving means [2] above, as an incombustible HFC-134a is used as a heating medium, even if the heating medium leaks into nhe water circulation line, there is no fear of explosion, fire, etc., and as the HFC-134a is of no poisonous nature and has zero ozone depletion potential, there is no problem in terms of global environment preservation. 3) In the solving means [3] above, as a flow control valve is provided to at least one of the conduit to supply the internal cooling water after used for cooling the power station machinery and equipment to the internal cooling water cooler and the conduit by which said internal cooling water by-passes said internal cooling water cooler so that the opening of the flow control valve is regulated based on the temperature of the internal cooling water to cool the power station machinery and equipment, the temperature of the internal cooling water can be freely-regulated corresponding to the generated heat amount of the power station machinery and equipment. This ensures that a heat source for heating and vaporizing LNG is secured irrespective of whether the generated heat amount of the power station machinery and equipment is large or small, and by setting the temperature of the internal cooling water high, the amount of the internal cooling water to be supplied to the heating medium evaporator can be decreased and the carrying power of the coolina water can also be reduced. 4) In the solving means [4] above, as a flow control valve is provided to at least one of the conduit to supply the water after used for cooling the gas turbine intake air to the heating medium evaporator and the conduit to supply the water after used for cooling the power station machinery and equipment to the heating medium evaporator so that the opening of the flow control valve is regulated based on the temperature of the heat source water supplied to the heating medium evaporator, the heat obtained by cooling the power station machinery and equipmer.i as an auxiliary heat source cf the heat obtained by cooling the gas turbine intake air can be utilized corresponding to a requirement and the temperature of the heat source water supplied to the heating medium evaporator can be kept at a predetermined value. 5} In the solving means [5] above, the first and the second heating medium evaporators are provided, and the heat source water, that is, at least one of the water after used for cooling the gas turbine intake air and the high temperature water after used for cooling the power station machinery and equipment, is first introduced into the second heating medium evaporator and cooled, then introduced into the first heating medium evaporator and cooled, and is supplied to at least one of the intake air cooler and the power station internal cooling water circulation line- And LNG is first introduced into the first LNG vaporizer, then supplied to the second LNG vaporizer and to the third LNG vaporizer in turns, and the LNG finally supplied to the third LNG vaporizer is heated by the high temperature heating medium vapor generated at the second heating medium evaporator to become NG of more than 0"C easily. On the other hand, the cooling water to be used for cooling the gas turbine intake air can be cooled to a low temperature within the range where the cooling water does not freeze at the first heating medium evaporator. This means that, while the temperature of the vapored NG is being kept more than 0°C, the temperature of the gas turbine intake air can be made low, thus the gas turbine intake air cooling effect can be enhanced. 6) In the solving means [6] above, the pressure of the heating medium in the first heating medium evaporator is detected, and the signal to regulate the water amount supplied to the first heating medium evaporator so that said pressure of the heating medium is kept constant and the demand signal of the desired water supply amount to be supplied to the first heating medium evaporator are compared each other, and based on the smaller one out of them, the water amount supplied to the first heating medium evaporator is regulated. As for the LNG supply amount, the pressure of the heating medium in the first heating medium evaporator is detected, and the signal to regulate the LNG supply amount so that said pressure of the heating medium is kept constant and the demand signal of the desired LNG supply amount are compared each other, and based on the smaller one out of them, regulation is made. By use of this means, if the control target value of the heating medium pressure in the first heating medium evaporator is set to the pressure higher than the saturated vapor pressure of the heating medium of temperature of 0"C, there occurs no freezing of water in the heating medium evaporator. Further, in the summer season where the gas turbine intake air cooling effect is wanted to be made maximum, under the condition that the control target value of the heating medium pressure to control the LNG supply amount is set to the value higher than the saturated vapor pressure of the heating medium of 0"C temperature and lower than the control target value of the heating medium pressure to control the water supply amount, the set value (demand signal) of the water supply amount is set to the flow rate permissible by the facilities and operation is made with the LNG supply amount being set to the maximum value. Then, water cooled by the facilities being maximized is obtained without being frozen and the gas turbine intake air cooling effect can be made maximum. Further, in the winter time where the power used for operation of the LNG vaporizing apparatus, that is, the power of the pump to supply the heat source water to the heating medium evaporator is wanted to be decreased, the temperature of the heat source water supplied to the second heating medium evaporator is set to a high temperature by use of the solving means [3] and [4] above and operation is made with the LNG supply amount being set to the desired value, then the flow rate of the heat source water becomes the minimum flow rate required for the vaporization of the LNG and the pump power can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS: Fig. 1 shows a diagrammatic view showing a half portion of a preferred embodiment according to the present invention. Fig. 2 shows a diagrammatic view showing the remaining half portion of said preferred embodiment according to the present invention. Fig. 3 is a diagrammatic view showing a means in the prior art to cool a gas turbine intake air by use of cold heat of LNG. Fig. 4 is a diagrammatic view showing an LNG vaporizing apparatus in the prior art. DESCRIPTION OF THE PREFERRED EMBODIMENTS: Fig. 1 and Fig. 2 are diagrammatic views showing a preferred embodiment according to the present invention, that is, said preferred embodiment is completed by X, Y and Z shown at the left end of Fig. 1 being connected to X, Y and Z, respectively, shown at the right end of Fig. 2 and hereafter descript ion is made with both portions being so connected. Numeral 1 designates a first heating medium evaporator provided with a heat transfer tube nest la within its body. A heating medium A contained in the body side of the first heating medium evaporator 1 is heated and evaporated by water supplied into the heat transfer tube nest la from a water supply conduit 23 through a water inlet 23i. The evaporated heating medium vapor is discharged from a heating medium vapor outlet 59. The water flown in the heat transfer tube nest la and cooled by the heat of vaporization of the heating medium A is discharged from a water outlet 226. Numeral 2 designates a body provided with a U-shaped tube nest 3a of a first LNG vaporizer 3 and a u-shaped tube nest 4a of a second LNG vaporizer 4, and to the body side of said body 2, the heating medium vapor evaporated at the first heating medium evaporator 1 is introduced from a conduit 5 through a heating medium vapor inlet 5i. On the other hand, LNG is first introduced into the first LNG vaporizer 3 from an LNG supply conduit 7 through sn LNG inlet 7i and is discharged into an LNG conduit 8 through the U-shaped tube nest 3a and an LNG outlet 86, and is further introduced into the second LNG vaporizer 4 from the LNG conduit 8 through an LNG inlet 8i and is discharged to an LNG conduit 9 through the U-shaped tube nest 4a and an LNG outlet 98. LNG is heated and vapored, while it flows through the U-shaped tube nests 3a and 4a, by the heating medium vapor supplied from the heating medium inlet 5i. On the other hand, the heating medium vapor is condensed and liquefied by heat ing and vaporizing LNG and the liquefied heating medium is discharged from a heat ing medium outlet 69 to circulate to the first heating medium evaporator 1 through a conduit 6 and a heating medium inlet 6i. That is, the body 2 containing the first LNG vaporizer 3 and the second LNG vaporizer is installed at a higher position than the installation position of the first heating medium evaporator 1 so that the heating medium makes self-circulation between the first heating medium evaporator 1 and the body 2 containing the first LNG vaporizer 3 and the second LNG vaporizer 4. The first LNG vaporizer 3 and the second LNG vaporizer 4 can be contained in separate bodies so that the heating medium vapor generated at the first heating medium evaporator 1 may be introduced separately and the number of the LNG vaporizers can be selected freely. But as a countermeasure for thermal stress, the tube plate of the first LNG vaporizer 3 to introduce a cryogenic LNG of less than -100°C is preferably small and it is necessary to take care not to enlarge the heat transfer area of the first LNG vaporizer 3. For this purpose, at the first LNG vaporizer 3, it is preferable that LNG is pre-heated, that is, heated near to the boiling point of LNG and vaporization operation of LNG which requires a large amount cf heat is done at the second LNG vaporizer 4. Further, in order to reduce facilities cost, it is advisable to contain the first LNG vaporizer 3 and the second LNG vaporizer 4 within one body 2. Numeral 10 designates a body,provided with a tube nest 12a of a second heating medium evaporator 12 and a U-shaped tube nest 11a of a third LNG vaporizer 11, and the heating medium A contained in the body side of the body 10 is heated and evaporated by the water supplied from a water supply conduit 24 through a water inlet 24 i to flow in the heat transfer tube nest 12a and discharged from a water outlet 239 to a water supply conduit 23. The evaporated heating medium vapor is condensed and Liquefied at the tube walls of the U-shaped tube nest 11a by heating LNG supplied from the LNG conduit 9 through an LNG inlet 9i to flow in the U-shaped tube nest 11a and drops on to the liquid surface of the heating medium A by its own weight. On the other hand, the LNG heated by the heating medium becomes NG of more than 0°C and is discharged to an NG conduit 13 from an NG outlet 138. The second heating medium evaporator 12 and the third LNG vaporizer 11 can be contained in separate bodies so tha t both bodies may be connected by a heating medium vapor conduit and a heating medium liquid conduit, like above-mentioned first heating medium evaporator 1 and body 2 containing the first LNG vaporizer 3 and the second LNG vaporizer, but in terms of reducing facilities cost, it is preferable to contain them in one body 10. The heating medium A to be filled in the first heating medium evaporator 1 and in the body 10.. of the second heating medium evaporator is required to be a substance to make vapor-liquid phase changes under the operational condition of the vaporizing plant so that vaporization is made at a heating medium evaporator and liquefaction is made at an LNG vaporizing apparatus and to transfer heat accompanying therewith. Further, it is preferably a substance with a low solidification point and of an incombustible and non-poisonous nature, having no problem in terms of the global environment preservat ion. As such a substance, for example, it is suitable to use 1,2,2,2-Tetrafluoroethane (HFC-134a), that is, the solidification point of HFC-134a is as low as -101°C and even in case of making vaporization of cryogenic LNG, there is no fear of obstructing a normal operation due to solidification of HFC-134a in the LNG vaporizer. While the largest fear of obstructing a normal operation of LNG vaporizing facilities is a freezing of heat source water in the heating medium evaporator, this problem can be solved by holding the temperature of the heating medium in the heating medium evaporator higher than 0°C by use of 3 means as described below. If HFC-134a is used as heating medium, the heat source water makes heat exchange with the liquid of HFC-134a and LNG makes heat exchange with the vapor of incombustible HFC-134a, that is, all the portions where the heat source water and LNG make direct heat exchanges in the LNG vaporizing apparatus in the prior art are excluded, hence no leakage of LNG into the heat source water occurs. Even if a leakage of LNG into the heating medium vapor occurs, for example, due to a defect of vaporizer, LNG does not exist in a liquid state under the operational condition of the heating medium and there is no mixing of LNG into the heating medium liquid in the heating medium evaporator s ide. Further, LNG leaking into the heating medium vapor becomes a non-condensing gas and obstructs heat exchange between the heating medium vapor and LNG. Due to this, even with a slight leakage, the pressure of the heating medium vapor line rises higher than the saturated vapor pressure of the heating medium. Accordingly, by observing the pressure and temperature of the heating medium vapor line by use of appropriate process instruments {not shown), a slight leakage of LNG can be detected easily and, based thereon, a countermeasure, such as stopping LNG supply, is taken and LNG leakage ir.to the heat source water can be prevented completely. LNG leakage into the atmospheric air can be easily detected by gas detecting means as so far employed in this kind of gas facilities. Thus, according to this preferred embodiment, the theme mentioned in (i) above can be solved and warm water of a power station can be used as heat source water. Numeral 21 designates gas turbine facilities consisting of main components of an air compressor 21a, a combustor 21b and a gas turbine 21c. NG as fuel is introduced into the combustor 21b from an NG conduit 13, air for combustion sucked by the air compressor 21a from an intake air duct 19 is supplied into the combustor 21b, and combustion gas is introduced into the gas turbine 21c. As widely known, as the air compressor 21a of the gas turbine 21c is of a constant volume type, if the temperature of the intake air becomes higher, the mass of the sucked air becomes smaller, and as a result the output of the gas turbine is lowered. Due to this, there is a shortcoming that, in the summer season where there is a large power ccr.surr.pt ion, the power generation comes down, and to solve this shortcoming is also one of themes here. That is, by making use of cold heat of LNG, the intake air of gas turbine 21c is intended to be cooled, and an intake air cooler 20 to coci the intake air cf the gas turbine 21c, having an air inlet 15;. and an air outlet 196, is connected to the intake air duct 19 of the gas turbine 21c. The intake air cooler 20, the second heating medium evaporator 12 and the first heating medium evaporator 1 are connected via an intake air cooling water circulation pump 25 by water conduits in the order of numerals 24, 23 and 22, thus a circulation line of gas turbine intake air cooling water is formed. That is, in order to change the cryogenic LNG of less than -100°C to NG of more than 0°C, the gas turbine infake air is cooled by water cooled by the heat of vaporization of the heating medium vapored at the second heating medium evaporator 12 and the first heating medium evaporator 1, the heating medium is heated and vapored by water heated by cooling the gas turbine intake air, and LNG is heated and vapored by the heating medium vapor as so vapored. As for the intake air of the gas turbine 21c, it is preferably cooled as much as possible so as to enhance the intake air cooling effect. For this purpose, in the intake air cooler 20, a finned heat transfer tube nest 20a for water flow is provided so as to connect a water inlet 22i and a water outlet 246. For this heat transfer tube nest of the intake air cooler, various types can be selected but a finned tube nest in which a pressure loss of air flow is small and a heat transfer area per unit volume of the intake sir cooler is large is appropriate. In order to enhance the intake air cooling effect, the temperature of the cooling water supplied to the intake air cooler 20, or of the water at the water outlet 229 of the first heating medium evaporator 1, is required to be made low, but this must be within a restriction that the vapored NG temperature is surely maintained higher than 0°C and no ice is generated in the water tubes of the heating medium evaporator. According to this preferred embodiment, as NG is finally heated by the heating medium heated and vapored by the warm water at the second heating medium evaporator 12, even if the water temperature at the first heating medium evaporator outlet 22 6 is made low, the temperature of the vapored NG can be made more than 0"C easily. Further, the places where ice is liable to be generated in the water tubes are within the water tubes of the first heating medium evaporator 1, but this can be also solved easily according to this preferred embodiment, as described below. If the atmospheric air temperature becomes low, all the amount of LNG required by a gas turbine combined cycle plant cannot be vapored only by the heat obtained by cooling the gas turbine intake air, but as a countermeasure therefor, in this preferred embodiment, the heat obtained by cooling the power station machinery and equipment, that is, a heat source as so far entirely wasted is intended to be used. Numeral 31 designates power station machinery and equipment, numeral 34 designates an internal cooling water circulation pump to circulate water to cool the power station machinery and equipment 31 (internal cooling water) and numeral 39 designates an internal cooling water cooler to cool the internal cooling water by the sea water. In the conventional means to cool the power station machinery and equipment, these machinery and equipment are connected by conduits 33, 35 and 32 and, thereby only, an internal cooling water circulation line is formed. That is, the internal cooling water heated by cooling the power station machinery and equipment 31 is sucked by the internal cooling water circulation pump 34 from the conduit 33 and supplied to the body side of the internal cooling water cooler 39 from the conduit 35 through a water inlet 35i. Then it is cooled by the sea water introduced from a conduit 40 and discharged from a conduit 41 through a heat transfer tube nest 39a and is discharged from a water outlet 325 to the conduit 32 so as to be used again to cool the power station machinery and equipment. The largest shortcoming in this conventional mear.s is that the internal cooling water temperature car.no: be well regulated to a predetermined value, which results in a difficulty to use the heat obtained by cooling the power station machinery and equipment 31 as a heat source for vaporizing LNG- But this difficulty can be solved easily by this preferred embodiment. In this preferred embodiment, in addition to the conduit 35 to connect the water outlet 356 of said internal cooling water circulation pump 34 and the water inlet 35i of said internal cooling water cooler 39, a conduit to let the internal cooling water flow by by-passing the internal cooling water cooler 39, that is, a conduit 36 to connect the conduit 32 connecting the water outlet 326 of the internal cooling water cooler 39 and the power station machinery and equipment 31 and said conduit 35 is provided and the water amount supplied to the internal cooling water cooler 39 is regulated, thereby the removed heat amount at the internal cooling water cooler 39 can be regulated. In order to regulate the removed heat amount at the internal cooling water cooler 39, in this preferred embodiment, flow control valves 37a and 37b to work reversely each other are provided to the conduit 3 5 to supply water to the internal cooling water cooler 39 from the internal cooling water circulation pump 34 and to the conduit 36 to let water flow by by-passing the internal cooling water cooler 39, and the temperature of the internal cooling water to be used for cooling the power stat ion machinery and equipment 31 is detected by a temperature detecting and regulating meter 37, and based on the detected value, the opening of the flow control valves 37a and 37b is controlled. As the water flowing in the flow control valve 37b is cooled by the internal cooling water cooler 39, its temperature becomes lower than that of the water flowing in the flow control valve 37a- Accordingly, if the detected temperature of the temperature detecting and regulating merer 37 is lower than the control target temperature, the opening of the flow control valve 37a is worked to the direction to open and the opening of the flow control valve 37b is worked reversely to the direction to close, and the internal cooling water temperature is controlled to the control target value. The object of this control is intended to regulate the removed heat amount of the internal cooling water cooler 39 so as to control the internal cooling water temperature to the predetermined value, and as for the flow control valves 37a and 37b, any one of them only may be installed and the installation position of the flow control valve also can be selected freely within the places where the amount of water supplied to the internal cooling water cooler 39 can be regulated. As mentioned above, by employing a means to be able to regulate the internal cooling water temperature to the predetermined value, the heat obtained by cooling the power station machinery and equipment 31 can be used as a heat source for LNG vaporization. More definitely, a conduit 38 to connect the conduit 24 connecting the water outlet 24 8 of said intake air cooler 20 and the water inlet 24 i of said second heating medium evaporator 12 via the intake air cooling water circulation pump 25 and the conduit 35 of said internal cooling water circulation line is provided, so that the water outlet 356 of said internal cooling water circulation pump 34 is connected to the water inlet 24i of said second heating medium evaporator 12 via the intake air cooling water circulation pump 25 and the internal cooling water after used for cooling the power station machinery and equipment 31 can be supplied to the heating medium evaporator. By so doing, the heat obtained by cooling the power s tat ion machinery and equipment 31 can be utilized as a heat source indirectly via the heating medium A. Further, the conduits 26, 28 to connect said conduits 24, 25 and the conduits 26, 29 to connect said conduits 24,32 are provided so that the water outlet 246 of said intake air cooler 20 and the water inlet 35i and the water outlet 325 of said internal cooling water cooler 39 are connected. Ey so doing, the water used for cooling the intake air of the gas turbine 21c can be returned in the same amount of the internal cooling water supplied to the intake air cooling water circulation line to the water inlet 35i of the internal cooling water cooler 39 or into the internal cooling water after cooled at the internal cooling water cooler 39. In order to regulate the amount of the internal cooling water supplied to the intake air cooling water circulation line, in this preferred embodiment, flow control valves 30a and 30b to work reversely each other are provided to the water suction side of the intake air cooling water circulation pump 25 of the conduit 24 connecting the water outlet 246 of said intake air cooler 20 and the water inlet 24i of said second heating medium evaporator 12 via the intake air cooling water circulation pump 25 and to said conduit 38, and the temperature of the water supplied to the second heating medium evaporator 12 is detected by a temperature detecting and regulating meter 30, and based on the detected value, the opening of the flow control valves 30a and 30b is controlled. In this control, the water flowing in the flow control valve 30a being a low temperature fluid and the water flowing in the flow control valve 30b being a high temperature fluid, if the detected Temperature of the temperature detecting and regulating meter 30 is lower than the control target value, the opening of the flow control valve 30a is worked to the direction to open and the opening of the flow control valve 30b is worked reversely to the direction to close, and the temperature of water supplied to the heat ing medium evaporator is controlled to the control target value. Incidentally, as for the flow control valves 30a, 30b, any one of them only may be installed and the installation position can be selected freely within the places where the amount of water supplied to the second heating medium evaporator 10 can be regulated. In the winter time when the atmospheric air temperature is low and there is no heed to cool the gas turbine intake air, the internal cooling water only is supplied to the heating medium evaporator and the water coming out of the heating medium evaporator is returned, as it is, without passing through the intake air cooler 20 into the water flow at the water inlet 35i or at the water outlet 326 of the internal cooling water cooler 39. That is, a conduit 22 to connect the water outlet 226 of the first heating medium evaporator 1 and the water inlet 22i of the intake air cooler 20 and a conduit 27 to connect to said conduits 28 and 29 are provided so that the water cooled at the heating medium evaporator is returned into the water flow at the water inlet 35i or at the water outlet 329 of the internal cooling water cooler 39. By so returning the water cocled at the heating medium evaporator to the water inlet 35i of the internal cooling water cooler 39, it is intended to heat the water cooled at the heating medium evaporator by the sea water usually used for cooling the internal cooling water, and in a plant where the heat amount treated at the internal cooling water line is small, this can be an effective means for securing heat source for LNG vaporization. The sea water temperature around the places where LNG firing gas turbine combined cycle power stations are installed in Japan is 7 to 8°C even in winter and the water cooled to 1 to 4"C at the heating medium evaporator can be heated thereby. That is, the water cooled to 1 to 4DC at the heating medium evaporator is heated near to the sea water temperature a- the internal cooling water cooler 39 and is further heated by the generated heat of the power station machinery and equipment 31 to become a heat source water for LNG vaporization. In case where only the heat input from the sea water at the "internal cooling water cooler and the generated heat at the power station machinery and equipment 31 are not enough as a required heat source for LNG vaporization, a separate auxiliary heat source for LNG vaporization becomes necessary. As this auxiliary heat source for LNG vaporization, steam obtained easily at a power station is appropriate, and a steam heater (not shown) often used industrially is provided to the discharge line of the intake air cooling water circulation pump 25 as a means to regulate the temperature of the heat source water supplied to the heating medium evaporator. On the other hand, in a combined plant where the heat amount treated at the internal cooling water line is large and a heat source for the required LNG vaporization is available enough, it is appropriate that the water cooled at the heating medium evaporator is returned to the water flowing out of the water outlet 329 of the internal cooling water cooler 39. This is for the purpose to use the water cooled at the heating medium evaporator for cooling the power station machinery and equipment 31, and by so doing, the heat load of the internal cooling water cooler 39 can be lowered and as a result the load of the sea water pump for the internal cooling water cooler can be lowered. Next, the control means around the LNG vaporizer according to this preferred embodiment is described: The function required for the control line around the LNG vaporizer is as follows: Cl, Under no operational condition, ice is generated in the water tubes of the heating medium evaporator. .3^ In the summer season when the atmospheric air temperature is high, if the supply amount of LNG is set to the maximum flow rate permissible by the facilities, the cooling water amount comes to the maximum flow rate permissible by the facilit ies and the cooling water temperature comes to the minimum temperature attainable by the performance of the facilities, and the gas turbine intake air cooling effect can be made maximum. (4) In the winter time when the gas turbine intake air cooling is not necessitated, if the supply amount of LNG is set to the same degree as the fuel consumption amount of the power generation plant, the flow rate of the heat source rater supplied to the heating medium evaporator comes to the ■ninimum flow rate reguired for LNG vaporization and the pump Dower can be decreased. The above-mentioned functions can be attained easily by use of control means of this preferred embodiment. Flow rate control means of water is described first. Numeral 18a designates a flow rate detector of water supplied to the second heating medium evaporator 12 and the firs t heating medium evaporator 1, numeral 18 designates a flow rate regulator of water and numeral 15b designates a flow control valve. And numeral 16b designates a pressure detecting and regulating meter of the first heating medium evaporator 1 and numeral 17 designates a water flow signal selector. The pressure detecting and regulating meter 16b works to give a signal in the direction to increase the water flow rate, or an output signal of larger value, if the pressure in the first heating med ium evaporator 1 becomes less than the set value and reversely a signal in the direction to decrease the water flow rate, or an output signal of smaller value, if the pressure becomes more than the set value. The water flow signal selector 17 has a function to take a demand signal of water supply amount or a set signal of the water supply amount and a signal from the pressure detecting and regulating meter 16b, select the smaller signal or the signal to make the opening of the water flow control valve 18b smaller, and give the signal to the water flow regulator 18. And the water flow regulator 18 has a function to take tha detected signal of the water flow detector 18a and the output signal of said water flow signal selector 17 and give a control signal to said water flow control valve 18b. Next, a con trol means of LNG supply amount is described. Numeral 14a designates a flow detector of LNG supplied to the LNG vaporizer, numeral 14 des ignates a flow regulator of LNG and numeral 14b designates a flow control valve of LNG. And numeral 16a designates a pressure detecting and regulating meter of the first heating medium evaporator 1 anz numeral 15 des ignates ar. LNG flow signal selector. The pressure detecting and regulating meter 16a works to give a signal in the direction to decrease the LNG flow rate or an output signal of smaller value, reversely from said case of water flow control, if the pressure in the first heating medium evaporator 1 becomes less than the set value and a signal in the direction to increase the LNG flow rate or an output s ignal of larger value, if the pressure becomes more than the set value. The LNG flow signal selector 15 has a function to take a demand signal of LNG supply amount and en output signal of the pressure detecting and regulating meter 16a, select the smaller signal out of them or the signal to make the opening of the LNG flow control valve 14b smaller, and aive the sianal to the LNG flow regulator 14. And the LNG flow regulator 14 has a function to take the detected signal of the LNG flow detector 14a and the output signal of the LNG flow signal selector 15 and give a control signal to said LNG flow control valve 14b. The pressure in the first heat ing medium evaporator 1 is nearly equal to the saturated vapor pressure of the heatir.g Teiium in said evaporator, and if the set value cf the pressure detecting and regulating meters 16a and I6b is .Tore than the saturated vapor pressure cf the heating rr.eciurr at -DC, the heating med ium temperature in the first heating Tedium evaporator 1 does not become less than 0 ° C, and there occurs no freezing of water in the tube nest of the firs t heating medium evaporator ia and also there is no generation cf ice within the tube nest 12a of the second heating medium evaporator to which the warm water before supplied to the first heat ing med ium evaporator 1 is supplied. Further, if the set value of the pressure detecting and regulating meter 16a to regulate the LNG flow rate is set to the permissible minimum value at the time when the LNG supply amount is made to the maximum flow rate permissible by the facilities (for example, the saturated vapor pressure of the heating medium at 0°C) and the set value of the pressure detecting and regulating meter 16b to regulate the water flow rate is set to the pressure by which the heating medium temperature does not become less than 0°C even at the time of LNG load changes (for example, the saturated vapor pressure of the heating medium a* I°C) , there is no generation of ice in the water tubes of the heating medium evaporator, and an operation tc f cliow the load changes of LNG and make the gas turbine intake air cooling effect maximum and an operation to make the pump power of said intake air cooling water circulat icr. pu~r 25 minimum can be dor.e easily . The reason therefor is describee further ir. detail. Description is made on a state that the de~ar.d signal of the water supply amount or the set value cf the wat er supply amount is set to the maximum flew rate permissible by the facilities, the set value of the pressure detecting and regulating meter 16a is set to the saturated vapor pressure of the heating medium at 0CC, the set value of the pressure detecting and regulating meter 16b is set to the saturated vapor pressure of the heating medium at 1DC and the heat source water temperature at the outlet cf the intake air cooling water circulation pump 25 is controlled to a predetermined temperature. First, if the demand signal of the LN"G supply amount is set to the maximum value for a purpose of maximizing the gas turbine in take air cooling effect, the pressure in the first heating medium evaporator 1 approaches near to the set value of the pressure detecting and regulating meter 16a and the heating medium temperature is lowered near to 0°C. In this state, the outpu: signal of the pressure detecting and regulating meter 16b ;o regulate the water flow rate becomes larger than the demand signal of the water supply amount, so that the output signal from the water flow signal selector 17 becomes equal to the demand signal of the water supply amount and the water supply amount is controlled to the maximum flow rate permissible by the facilities (set value). On the other hand, the output signal of the pressure detecting and regulating meter 16a zo regulate the LNG supply amount becomes smaller than the demand signal of the LNG supply amount, so that the output signal from the LNG flow signal selector 15 becomes equal to the signal from the pressure detecting and regulating meter 16a and the LNG supply amount is controlled so that the pressure in the firs t heat ing medium evaporator 1 is the set value of the pressure detecting and regulating meter 16a. In this state, as the water supply amount and the LNG supply amount are in the maximum flew rate permiss ibie by the facilities and the heating medium temperature in the first heating medium evaporator 1 is likewise minimum, the temperature of the water cooled by this heat ing medium also becomes low. That is, the cooling water supplied to the intake air cooler 20 is in the maximum flow rate permissible by the facilities and is cooled with the performance of the facilities being maximized, and the maximum intake air cooling effect is realized. Further, in this state, the flow velocity of the w=ter in the water tubes la of the first heat ing mediurr 1 is maximum so that ice is hardlv generated, and the load :: LNG is also maximum so that there is no load increase cf LNG, hence even if the heating medium temperature in the first heating medium evaporator 1 is made to 0"C, there is r.o fear cf ice being generated in the water tubes . incidentally , w ith such an operat ion being ;i\ade , there may be a case wr.ere the vapored NG amount becomes more than the fuel consumption of the power stat ion, and in this case the surplus NG is used as fuel for other purposes. Next, in the winter time etc. when the intake air cooling is not necessitated, the LNG supply amount is reduced nearly to the fuel consumption of the power station and the characteristic of the line at this time is described. If the LNG supply amount is set to a small value of demand signal, the pressure in the first heating medium evaporator 1 comes near to the set value of the pressure detectina and regulating meter 16b so that the temperature of the heating medium rises near to 1CC and the output signal of the pressure detecting and regulating meter 16b becomes smaller than the demand signal of the water supply amount so that the output signal from the water flow signal selector 17 becomes equal to the signal from the pressure detecting and regulating meter 16b, thus the water suppiv amount is controlled at the required minimum flow rate at which the pressure in the first heating medium evapora tor 1 becomes equal to the set value of the pressure detecting ar.o regulating meter 16b. On the other hand, the output signal of the pressure detecting and regulating meter 16a to regulate the LNG supply amount oecomes larger than the demand signal cf the LNG supply amount so that the output signal from the LNG flow signal selector 15 becomes equal to the demand signal of the LNG supply amount and the LNG supply amount is controlled at the demand signal of the LNG supply amount. That is, according to this preferred embodiment, the heat source water amount to vaporize the required LNG can be made to the required minimum and the power required for the LNG vaporization operation can be saved. Especially, in the winter time when the intake air cooling is not necessitated, the temperature of the heat source water is set to the higher side by use of the means ment ioned in [3] above and the saving effect of the power required fcr the LNG vaporization is further enhanced. And, under the condition that the LNG supply amount is less than the limit value of the facilities capacity and the load increase of LNG may occur, the temperature of the heating medium in the first heating medium evaporator 1 is kept high and the flow rate of the heat source water also is operated enough within the facilities capacity, and even if the load of LNG is elevated, the LNG vaporization operation can be done without generation of ice in the water tubes of the first heating medium evapora tor 1. Incidentally, in this preferred embodiment, trie conduits 22 and 27 connected fram the water cutlet 22 f if the first heating medium evaporator 1 and the conduits 24 and 26 connected from the water outlet 246 of the in rake air cooler 20 are described as being connected to the conduit 28 connected to the water inlet 35i &nd the conduit 29 connected to the water out let 32G of the internal cooling water cooler 39, but if flow control valves or flow regulating valves are provided, according to the necessity, on the half way of said conduits 26, 27, 28 and 29 and each flow control valve or flow regulating valve is operated with mutual relations, control and regulation with various flow distributions according to the operational state of the power station become possible and such examples are naturally included in the range of technological concept of the present invention. Further, the present invention is not limited to said preferred embodiment but may be added with various modifications in its definite construction within the scope of the present invention defined in the appended claims. As clarified by "he above detailed descript ions, following effects can be obtained according to the present invention: (a) By making use cf the cold heat of LNG as fuel for a natural gas firing gas turbine combined cycle power station, the gas turbine ir.ta-;e sir cooling becomes possible to that lowering of the output zt the power station in the summer season can be prevented. (b) As the vaporization heat source of LNG as fuel for a power station, not only the heat source obtained by cooling the gas turbine intake air but also the high quality heat source obtained by cooling the power station machinery and equipment and the heat input from the sea water of the internal cooling water cooler which is indispensable for power station can be made use of corresponding to the requirement, hence even in winter, LNG in the amount required at the power station can be vaporized stably and, not necessarily limited to the winter time. the power and the auxiliary heat source required for vaporization operation of LNG can be saved. (c) As the closed loop system of the internal cooling water is used for the delivery and receipt of heat between the LNG vaporizing facilities and the power generation facilities, that is, for carrying out above-ment ioned (a] and (b), various problems accompanying with using the sea water, such as installation, cf special facilities of sea water intake and discharge facilities etc., maintenance of such facilities against parasitism or sticking of marine living things, discharge of cold or warm water into the public sea area, etc. as seen in the conventional LNG vaporizing facilities usir.g the sea water as a heat source for LNG vaporization car. be avoided and yet preservation of the water quality cf the internal cooling water is facilitated because of closed loop system. (d) 3y making the heat exchange between the heat source water and the LNG via an incombustible heating medium, leakage of combustible gas from the LNG vaporizing facilities to the outside of the line, especially to the power generation facilities is prevented and safety of the power station can be secured in carrying out above (a), (b) and (c ) . ( e) Following the load changes of the power station, vapored NG which is appropriate as fuel for the power station is generated at any time in the amount required and a fear of water freezing in the facilities to obstruct normal operation of facilities is dissolved, thus the LNG vaporizing facilities according to the present invention provides power station fuel facilities of high reliability. That is, the present invention provides a vaporizing apparatus of LNG as fuel for a natural gas firing gas turbine combined cycle power station which is excellent in performance, safety and economy, and is most suitable for the cublic use. WE CLAIM: 1. A vaporizing apparatus of LNG as fuel for a natural gas firing gas turbine combined cycle power station comprising an LNG vaporizer to heat LNG by heating medium vapor via a metal wall as well as to cool and condense said heating medium vapor; a heating medium evaporator to heat and evaporate by water a heating medium liquid cooled and condensed at said LNG vaporizer to generate said heating medium vapor as well as to cool said water; an intake air cooler to cool a gas turbine intake air for a natural gas firing gas turbine combined cycle power station by said water cooled by said heating medium evaporator; an internal cooling water cooler to cool water for cooling machinery and equipment at said power station by the sea water; a conduit to connect a water outlet of an internal cooling water circulation pump to a water inlet of said internal cooling water cooler, said internal cooling water circulation pump supplying the water after used for cooling said machinery and equipment at the power station to said internal cooling water cooler; a conduit to connect said water outlet of the internal cooling water circulation pump to said machinery and equipment at the power station by by-passing said internal cooling water cooler; a conduit to connect a water outlet of said intake air cooler to a water inlet of said heating medium evaporator; a conduit to connect the water outlet of said internal cooling water circulation pump to the water inlet of said heating medium evaporator; a conduit to connect a water outlet of said heating medium evaporator to a water inlet of said intake air cooler; and a conduit to connect at least one of the water outlet of said heating medium evaporator and the water outlet of said intake air cooler to at least one of the water inlet and the water outlet of said internal cooling water cooler. 2. A vaporizing apparatus as claimed in claim I, wherein said heating medium is 1,2, 2, 2-Tetrafluoroethane (HFC - 134a). 3. A vaporizing apparatus as claimed in any one of claims 1 and 2, wherein an internal cooling water temperature regulating flow control valve is provided to at least one of the conduit to connect the water outlet of said internal cooling water circulation pump to the water inlet of said internal cooling water cooler and the conduit to connect the water outlet of said internal cooling water circulation pump to said machinery and equipment in the power station by by- passing said internal cooling water cooler; a temperature detecting meter to detect a temperature of water to cool said machinery and equipment at the power station; and a means to regulate the opening of said internal cooling water temperature regulating flow control valve based on a detected value of said temperature detecting meter. 4. A vaporizing apparatus as claimed in any one of claims 1 to 3, wherein a heating medium evaporator supply water temperature regulating flow control valve is provided to at least one of the conduit to connect the water outlet of said intake air cooler to the water inlet of said heating medium evaporator and the conduit to connect the water outlet of said internal cooling water circulation pump to the water inlet of said heating medium evaporator; a temperature detecting meter to detect a temperature of water supplied to said heating medium evaporator; and a means to regulate the opening of said heating medium evaporator supply water temperature regulating flow control valve based on a detected value of said temperature detecting meter. 5. A vaporizing apparatus as claimed in any one of claims 1 to 4, wherein a first heating medium evaporator is provided in a heating medium liquid phase of a first heating medium evaporator body, said first heating medium evaporator body having a heating medium vapor phase in its upper portion and said heating medium liquid phase in its lower portion; a first LNG vaporizer and a second LNG vaporizer are disposed in a body at a higher position than the installation position of said first heating medium evaporator, said body being connected of its upper portion by a conduit to said heating medium vapor phase in said first heating medium evaporator body and of its lower portion by a conduit to said heating medium liquid phase of said first heating medium evaporator body; a third LNG vaporizer contained in a heating medium vapor phase in the upper portion of a body enclosing a heating medium is provided a second heating medium evaporator contained in a heating medium liquid phase in the lower portion of said body enclosing said heating medium; a conduit to connect an LNG outlet of said first LNG vaporizer to an LNG inlet of said second LNG vaporizer; a conduit to connect an LNG outlet of said second LNG vaporizer to an LNG inlet of said third LNG vaporizer; a conduit to connect a water inlet of said heating medium evaporator to a water outlet of said intake air cooler and to the water outlet of said internal cooling water circulation pump; a conduit to connect a water outlet of said second heating medium evaporator to a water inlet of said first heating medium evaporator; and a conduit to connect a water outlet of said first heating medium evaporator to a water inlet of said intake air cooler. 6. A vaporizing apparatus as claimed in claim 5, wherein a water supply amount control means consisting of a pressure detecting and regulating meter to detect a pressure of said first heating medium evaporator and give a control signal, a water flow signal selector to take an output signal of said pressure detecting and regulating meter and demand signal of water supply amount and give the smaller signal out of them as a set signal of the water supply amount, a water flow detector to detect a flow rate of water supplied to said first heating medium evaporator, a water flow regulating meter to take a detected signal of said water flow detector and an output signal of said water flow signal selector and give a water flow control signal and a water supply amount control valve to control water supply to said first heating medium evaporator based on an output signal of said water flow regulating meter; and an LNG supply amount control means consisting of a pressure detecting and regulating meter to detect a pressure of said first heating medium evaporator and give a control signal, an LNG flow signal selector to take an output signal of said pressure detecting and regulating meter and a demand signal of LNG supply amount and give the smaller signal out of them as a set signal of the LNG supply amount, an LNG flow detector to detect a flow rate of LNG supplied to said first LNG vaporizer, an LNG flow regulating meter to take a detected signal of said LNG flow detector and an output signal of said LNG flow signal selector and give an LNG flow control signal and an LNG flow control valve disposed at the LNG inlet of said first LNG vaporizer and controlled by an output signal of said LNG flow regulating meter. 7. A vaporizing apparatus substantially as herein described with reference to the accompanying drawings.

Documents:

1026-mas-1996 abstract duplicate.pdf

1026-mas-1996 abstract.pdf

1026-mas-1996 claims duplicate.pdf

1026-mas-1996 claims.pdf

1026-mas-1996 correspondence others.pdf

1026-mas-1996 correspondence po.pdf

1026-mas-1996 description (complete) duplicate.pdf

1026-mas-1996 description (complete).pdf

1026-mas-1996 drawings duplicate.pdf

1026-mas-1996 drawings.pdf

1026-mas-1996 form-2.pdf

1026-mas-1996 form-26.pdf

1026-mas-1996 form-4.pdf

1026-mas-1996 form-6.pdf

1026-mas-1996 petition.pdf