Title of Invention

AN AIR CONDITIONING SYSTEM FOR A VEHICLE

Abstract

The invention relates to an air conditioning system for a motor vehicle comprising a coolant circuit (1) that contains an electrically driven compressor (2), a condenser (4), an expansion valve (10) and a latent cold accumulator (12). Heat is removed from the latent cold accumulator (12) by means of the cooling circuit (1); this is referred to as the charging of the latent cold accumulator (12). The system is also equipped with means for cooling air, which are configured in such a way that heat is removed from said air and supplied to the latent cold accumulator (12). Thus the cost-effective, efficient air conditioning system can be used, in particular, when the vehicle is stationary.

Full Text

Air conditioning system for a vehicle The invention relates to an air conditioning system for a vehicle having a refrigerant circuit which comprises a compressor, a condenser, an expansion valve and a latent cold storage the heat of which can be drawn by means of the refrigerant circuit. This drawing of heat is referred to as charging. Furthermore, the air conditioning system comprises means for cooling air, which is formed such that heat is drawn from the air and the heat is supplied to the latent cold storage. This supply of heat is referred to as discharging. In particular, such an air conditioning system is used for motor trucks. In particular, it is used there as a stationary air conditioning system. A stationary air conditioning system for a vehicle is known from DE 198 52 641 Cl, having a refrigerant circuit with a compressor, a liquefier, an accumulator and at least one ice storage unit. The ice accumulator unit consists of a vaporizer with an expansion organ and an ice accumulator surrounding the latter. Furthermore, a further vaporizer with an expansion organ is connected in parallel to the at least one ice accumulator unit, wherein it can be controlled by means of respective switching valves, if the refrigerant flows through the further vaporizer or the vaporizer of the ice accumulator unit. The compressor is mechanically driven by a driving motor of the vehicle and can be coupled with the latter by means of a magnetic clutch via a fan belt. It is the object of the invention to provide a compact air conditioning system which is adapted to cool a vehicle in a stationary operation of the vehicle. This object is solved by the features of the independent claims. Further advantageous formations of the invention are subject matter of the dependent claims. The invention is characterized by an air conditioning system for a vehicle having a first refrigerant circuit which comprises an electrically driven compressor, a condenser, an expansion valve and a latent cold storage the heat of which is drawn by means of the refrigerant circuit, and having means for cooling air which is formed such that heat is drawn from the air and the heat is supplied to the latent cold storage. By means of the electrically driven compressor the power of the compressor can be adjusted independently on the rotational speed of a driving shaft of the vehicle and, if necessary, the compressor can also be provided with electrical energy independently on the drive of the vehicle. Thereby, a predetermined amount of heat can be drawn from the latent cold storage in the simply manner also during extreme hotness. If a further primary air conditioning system is disposed in the vehicle, the compressor of which is driven by the driving shaft of the vehicle, for example by the crank shaft, the charging of the latent cold storage of the air conditioning system can also be affected quickly when the compressor of the primary air conditioning system is operated at its maximal capacity. The latent cold storage is characterized by a very high specific cold capacity. This has the advantage that the air conditioning system can be formed very compact. In particu lar, it can draw a high amount of heat from the air in the stationary operation of the vehicle when the driving shaft does not rotate. In an advantageous formation of the invention, the air conditioning system hast a refrigerant circuit which comprises a pump, the latent cold storage and a heat exchanger by means of which heat is drawn from the air and the heat is then supplied to the latent cold storage. This has the advantage that the heat exchanger can be disposed at any position in the vehicle. In a further advantageous formation of the invention, a blower is assigned to the heat exchanger which influences the air flow through the heat exchanger and simultaneously influences the air flow through a heating element. This has the advantage that only one blower is necessary for cooling the air on the one hand and for heating the air on the other hand. In particular, it is advantageous when the heating element is a heating heat exchanger through which a fluid flows which can be heated by means of a fuel heating device. With a heating element formed in such a manner a notably high heating power is possible. In a further advantageous formation of the invention, the latent cold storage is disposed such that the air to be cooled flows through the latent cold storage and, at the same time, is cooled by the latter. Thus, the air conditioning system can be formed notably compact. In this context it is notably advantageous when the refrigerant circuit comprises a plurality of latent cold storages. Accord- ingly, cooling at many positions of the vehicle can be affected. In particular, this is advantageous in motor trucks which have, besides a driver compartment, a sleeping/living compartment formed separately of the latter. In a further advantageous formation of the invention, a generator is assigned to the air conditioning system which is driven by a driving shaft of a drive of the combustion engine and, thus, provides the electrical energy of the electrically driven compressor. In such a manner, the electrical driven compressor can be operated with high power during the driving operation. Embodiments of the invention are illustrated on the basis of the schematical drawings, wherein: Figure 1 shows a first embodiment of the air conditioning system, Figure 2 shows a second embodiment of the air conditioning system, Figure 3 shows a third embodiment of the air conditioning system, Figure 4 shows a fourth embodiment of the air conditioning system, Figure 5 shows a fifth embodiment of the air conditioning system, Figure 6 shows a sixth embodiment of the air conditioning system. Elements of the same construction and function are identified with the same reference numerals in all drawings. An air conditioning system (figure 1) is disposed in a vehicle, in particular in a motor truck. It has a refrigerant circuit 1 which comprises an electrically driven compressor 2, a condenser 4 which has assigned a condenser blower 6 thereto, an accumulator 8, an expansion valve 10 and a latent cold storage 12. The expansion valve 10 can be controlled or can merely be formed as a flow restrictor. The compressor 2 is connected with its output to the condenser 4 via a first line 14 which, in turn, is connected with its output to the accumulator 8 via a second line 16, which, preferably, also comprises a drier. The accumulator 8 is connected with the expansion valve 10 via a third line 18, which is connected with its output to the latent cold storage via a fifth line 22. The latent cold storage 12 is connected with its output to an input of the compressor 2 via a fifth line 22. The electrically driven compressor 2 is preferably supplied with electrical energy from a generator 24 which is driven by a driving shaft 26 of a drive 28 of the vehicle. For example, the drive 2 8 can be a combustion engine. However, the electrically driven compressor can also be supplied with electrical energy in another way, for example by means of a fuel cell or any elements outputting electrical energy, for example a battery. Also, the electrically driven compressor can be supplied with electrical energy by any combination of the elements enumerated exemplary. By a respective dimensioning of these elements, the electrically driven compressor 2 can be operated with a power which is sufficient also under extreme operating conditions in order to draw the desired amount of heat from the latent cold storage 12. During the operation of the electrically driven compressor 2, the refrigerant which can be for example R134a or also CO2 is compressed, whereby its temperature increases. The condenser 4 is formed in cooperation with the condenser blower 6 such that heat is drawn from the refrigerant by the air flowing through the condenser 4. The thus cooled and liquefied refrigerant flows further to the accumulator 8 via the second line 16 and, thence, to the expansion valve 10 via the third line 18 by means of which it is expanded to a lower pressure, wherein the temperature of the refrigerant decreases significantly. Subsequently, the refrigerant flows to the latent cold storage 12 and, there, draws heat from the cold storage medium by vaporizing it. The refrigerant which is then gaseous again flows further to the electrically driven compressor 2 via the fifth line 22 and, there, is compressed again. The high specific cold capacity of the latent cold storage 12 results from the fact that the cold storage medium in the latent cold storage is drawn energy by means of the refrigerant such that a phase transition from a liquid state to a solid state occurs. Thus, the latent cold storage can be formed compact. Furthermore it can be produced cheap. When the refrigerant is CO2, it is preferred that the condenser 4 is a gas cooler and the lines 18, 22 contact each other in a internal heat exchanger and the accumulator is disposed in the line 22. The air conditioning system comprises a refrigerant circuit 30 which has a heat exchanger 32, a pump 34 and a latent cold storage 12. The latent cold storage 12 is connected to the heat exchanger 32 via a sixth line 36 an output of which is connected with an input of the pump 34 via a sev- enth line 38. The pump 34 is connected with its output to the latent cold storage 12 via an eighth line 40. Preferably, the pump 34 is electrically driven and, for example, can obtain the electrical energy necessary for it from a battery not shown. The pump 34 pumps the refrigerant of the refrigerant circuit through the latent cold storage 12, wherein the latent cold storage 12 is supplied with heat and is cooled in this manner. The cooled refrigerant then pours or flows to the heat exchanger 3 2 through the sixth line 36 which is supplied with air by a blower 42 in a controlled manner which then delivers the heat to the heat exchanger 32 and, thus, is cooled and contributes to the desired cooling of the internal space of the vehicle. The heat exchanger 32 can be disposed in the region of the passenger compartment or can also be disposed in a sleeping or living room of the vehicle. The heat delivered from the flowing air heats the refrigerant in the heat exchanger 32 and, thus, the heated refrigerant flows to the pump 34 via the seventh line 38 where it is pumped again to the latent cold storage 12. It is preferred that the electrically driven compressor 2 is operated during the driving operation of the vehicle and, thus, heat is drawn from the latent cold storage 12. During the stationary operation of the vehicle, it is preferred that the compressor 22 is not operated or, at the most, is operated with a low electrical power. In the stationary operation the pump 34 is driven dependent on the required cooling power and, accordingly, air is cooled in the vehicle by means of the refrigerant circuit 30. In a second embodiment (figure 2) of the invention, in addition a heating element is provided which is a heating heat exchanger 44, wherein fluid, preferably a water glycol mixture, is flowing through the latter which can be heated by means of a fuel heating device 46 and is supplied to the heating heat exchanger 44 via a ninth line 48. The heating heat exchanger 44 is disposed such that the blower 44 also controls the air flowing through the heating heat exchanger 44. Thus, simply with one blower 44, the air flowing through both the heating heat exchanger 44 and the air flowing through the heat exchanger 32 can be controlled. In a third embodiment (figure 3) of the air conditioning system, an air heating element 50 is provided which, for example, can be formed as a PTC-resistance element and, thus, transforms electrical energy to heat and which is disposed such that the amount of air which flows next to the air heating element 50 is controlled by means of the blower 42. For example, the air heating element 50 can be formed as fuel air heating device. In a fourth embodiment (figure 4) of the air conditioning system, the blower 42 is assigned to the latent cold storage 12 and controls such that the air to be cooled flows through the latent cold storage or flows next to cooling fins which are assigned to the latter and, thus, delivers heat to the latent cold storage 12 and is thus cooled. In this way the air conditioning system can be formed notably compact, since the refrigerant circuit 30 can be omitted, in particular when at the plurality of positions of the vehicle, a cooling of the air has to be affected, it is advantageous in this context when the air conditioning system comprises a plurality of latent cold storages 12. This plurality of latent cold storages 12 can then be disposed at respective positions of the vehicle, for example the latent cold storage 12 in a motor truck can be disposed in the passenger compartment and the further latent cold storage 12 can be disposed in a sleeping and/or living room which is separately formed of the latter. In the fourth embodiment of the air conditioning system, the fuel heating device 46 and the heating heat exchanger 44 or the air heating element 50 according to the embodiments of figures 2 and 3 can also exist. In a fifth embodiment of the air conditioning system (figure 5), the fuel heating device 46 is disposed in a bypass 48 of the refrigerant circuit 30. In a sixth embodiment of the air conditioning system, the fuel heating device 46 is coupled to the sixth line 36. CLAIMS 1. An air conditioning system for a vehicle having a re frigerant circuit (1) which comprises an electrically driven compressor (2), a condenser (4), an expansion valve (10) and a latent cold storage (12) from which heat is drawn by means of the refrigerant circuit (1), and having means for cooling air which is formed such that heat is drawn from the air and the heat is supplied to the latent cold storage (12). 2. The air conditioning system according to claim 1, wherein the means for cooling air comprises a refrigerant circuit (30) which comprises a pump (34), the latent cold storage (12) and a heat exchanger (32) by means of which heat is drawn from the air which is then supplied to the latent cold storage (12). 3. The air conditioning system according to claim 2, wherein a blower (32) is assigned to the heat exchanger (32) which influences an air flow through the heat ex changer (32) and simultaneously influences the air flow through a heating element. 4. The air conditioning system according to claim 3, wherein the heating element is a heating heat exchanger (44), wherein a fluid flows through the latter which can be heated by means of a fuel heating device (46). 5. The air conditioning system according to claim 1, wherein the latent cold storage (12) is disposed such that the air to be cooled flows through the latent cold storage (12) and, in this way, is cooled. 6. The air conditioning system according to claim 5, wherein the refrigerant circuit (1) comprises a plurality of latent cold storages (12) . 7. The air conditioning system according to any of the preceding claims, wherein a generator (24) is assigned thereto which is driven by a driving shaft (26) of a drive (28) of the vehicle and, thus, provides the electrical en ergy for driving the electrical driven compressor (2).

Documents:

2638-CHENP-2006 CORRESPONDENCE OTHERS.pdf

2638-CHENP-2006 CORRESPONDENCE PO.pdf

2638-CHENP-2006 FORM-3.pdf

2638-CHENP-2006 POWER OF ATTORNEY.pdf

2638-chenp-2006-abstract.pdf

2638-chenp-2006-claims.pdf

2638-chenp-2006-correspondnece-others.pdf

2638-chenp-2006-description(complete).pdf

2638-chenp-2006-drawings.pdf

2638-chenp-2006-form 1.pdf

2638-chenp-2006-form 18.pdf

2638-chenp-2006-form 3.pdf

2638-chenp-2006-form 5.pdf

2638-chenp-2006-pct.pdf