Title of Invention

PHASE CHANGE MATERIAL

Abstract

The present invention relates to a Phase change material (PCM) comprising hexa-hydrated calcium chloride at least 85% by weight, strontium or its compound at least 0.1% by weight, and borax or its compounds 0-15% of weight. The invention also related to a process of preparing phase change material(PCM) with phase change temperature in the range of about 28-30deg c. The phase change material (PCM) material as obtained is packed in various containers such as extruded high density polyethylene (HDPE) panel or pouch, ball, cups or any container for intended application.

Full Text

Field of the invention The present invention is a divisional application arising out of Indian patent application no. 1588/DEL/2004. The present invention relates to a phase change material composition and its application for stabilizing the temperature in telecom shelter, electronic enclosures etc. The invention also relates to a process of producing the phase change material (PCM). Back Ground of the invention Electrical cabinets, shelters, cold storage and electronics enclosures require cooling system to protect precious internal item from permitted temperature limits. Human also need temperature controlled environment (permitted temperature range) for comfort living. Presently traditional cooling/ heating is provided using various devices like air conditioner, heat exchangers, fans. Whenever there is power failure the backup power like Diesel Gensets (DG) start to supply power to cooling/ heating device to maintain the temperature. It becomes very critical if DG does not start or cooling/ heating device fails and not possible to repair within the time frame. The electronic enclosure or telecom shelter inside temperature starts rising and if the alternate arrangement is not provided, the inside equipment can trip off the telecom/ electronic unit. The traditional systems have many disadvantages as follows: 1. Dependent on Power -Traditional cooling/ heating system work continuously to maintain permitted temperature range. The problem arises once the power is not available or cooling/ heating systems fails. The user has to immediately arrange for backup power or cooling / heating system to protect internal item. To ensure this, the alternative backup DG power and alternative cooling system has to be present. 2. High Running Cost - in order to maintain the temperature during power failure, alternate power supply like generator etc is required. This results in higher operational cost like diesel consumption, frequent DG maintenance. 3. DG Pollution - Continuous operation of DG creates noise and air pollution. This is especially very particular for the telecom shelters, which are scattered all over the places. 4. Risk Factor - High risk for service loss for telecom operator, if the DG or cooling device fails. Objects of the present invention:- It is a primary object of the present invention to provide Thermal Backup during power failure or Cooling/ Heating system failure. Another object of the invention is to provide thermal backup using phase change material. Description of the present invention: Accordingly, the present invention provides a Phase Change material (PCM) comprising hexa-hydrated calcium chloride at least 85% by weight, strontium or its compound at least 0.1% by weight, and borax or its compounds 0-15% of weight. The phase change temperature provided by the phase change material is in the range of about 28-30deg c. The process of changing from solid to liquid state (melting) or liquid to solid state (solidifying) is known as phase change process. When a substance changes phase, a large amount of energy in the form of heat is absorbed or released at a relatively constant temperature. This energy is called latent heat of the phase change material (PCM). In an embodiment of the invention related to providing phase change material (PCM) material packaged in various containers for the intended application. The packaging may be made in high density polyethylene (HOPE) panel or pouch, ball, cups or any container. In another embodiment of the invention related to a process for the preparation of Phase Change Material composition comprising mixing a calcium salt with strontium or its compound and optionally borax or its compound to obtain the desired composition. The calcium salt is calcium chloride hexa-hydrate or Calcium chloride mixed with water to obtain calcium chloride hexa hydrate. The calcium salt used in the phase change material (PCM) composition is at least 85% by weight. The strontium or its compound used for the above phase change material (PCM) is selected from a ground consisting of strontium chloride, strontium hydroxide, hydrates of strontium chloride, strontium sulphate, strontium phosphate, strontium nitrate, and hydrates of strontium hydroxide or mixtures thereof. The strontium or its compound used to obtain phase change material (PCM) is at least 0.1 %by weight. The borax or its compound is in the range of 0-15% by weight. The phase change material (PCM) packaged and tested & packaged in pouch, panel, cups and balls, which have been covered under invention to maintain required temperature in electronic enclosure, telecom shelter along with PCM - DG management circuitry, residential & commercial buildings, water tanks & clothing jackets and car seats. The final compound checked for its latent heat, charging & discharging temp using DSC (Differential Scanning Calorie Meter). The packaged phase change material (PCM) also tested in hot and cold chamber to ensure packaged phase change material (PCM) quality. The process of preparation and packaging are as per above mentioned various options ensure, right thermal backup solution for different applications and need. The phase change material composition is not a mere admixture but a synergistic composition where all the ingredients are not reacting but are interacting with each other to form a new substance having different properties from its components because of process of mixing and utilization (installation). Various alterations and modifications are possible without deviating from the scope of the claimed invention; hence, the same should not be construed to restrict the scope of the invention. The following paragraph explain various application of phase change material (PCM) 1. The telecom shelters will be engineered with air conditioner required kilo watt hours (KWH) of thermal backup of phase change material (PCM) installed along with air circulation fan. The phase change material (PCM) panel installed in telecom shelter gets charged during power availability and air conditioner running. The phase change material (PCM) used in telecom shelter 28-30 deg C as designed threshold temperature to maintain thermal backup upto 35 deg C recommended for longer life of electronic equipment and it's battery. The phase change material (PCM) gets charged (freezed) during air conditioner running which is set 1 - 4 deg C lower than selected threshold temperature of phase change material (PCM) . Whenever there is power cut or air conditioner fails, phase change material (PCM) starts absorbing heat to maintain shelter inside temperature up to 2 to 6 deg C higher than threshold temperature of phase change material (PCM) (28 - 30 Deg Cel) for certain time period. This is called thermal backup period (TBP). TBP is calculated based on KWH thermal backup needed for particular site. The mass of the phase change material (PCM) is selected by calculating latent heat storage capacity of a specific phase change material (PCM) per kilogram. During thermal backup no air conditioner and DG are needed. This avoids DG running and save equipment installed in the shelter against rise in temperature inside the shelter. The specific threshold temperature of phase change material (PCM) recommended as per site load and condition. 2. Phase change material (PCM) used for commercial and residential buildings have been designed and tested using 28 to 30 deg C this reduce air conditioning and heating need during power failure. The other option to use off peak power during night, charge the phase change material (PCM) by heat or cooling and maintain the temperature during day time. This improves the power utilization of the grid which is wasted during night, when there is no demand. This also reduces air conditioning cost for the user, using cheap night time power. 3. The phase change material (PCM) is also used, to absorb ambient temperature once it is lower than phase change material (PCM) threshold temperature for house, telecom shelter & electronic enclosure and maintain required temperature whenever outside temperature is higher than phase change material (PCM) threshold temperature to avoid air conditioning and hence power saving. 4. The phase change material (PCM) filled in Al foil coated with polyethylene (PE) can be used in jackets for maintaining body temperature during extreme cold or hot. phase change material (PCM) maintains the body temperature as per TBP. This is further useful for fire fighting and defence use during extreme cold or hot weather. 5. The phase change material (PCM) invention will also works to store thermal energy using boiler and giser during night time of off peak electricity, while use the same thermal energy or hot water in day time. Installation of phase change material (PCM) - 1. Telcom Shelter/ electronic/ Electrical Enclosure - The phase change material (PCM) processed for 28 to 30 Deg Cel are used for this application, it works with the additional electronics circuit designed for this application called PCM-DG management circuitry, works with the logic of telecom shelter temperature sensing and battery voltage sensing. Once the power is available the phase change material (PCM) gets charged using active cooling solution devices at a temperature 1-5 degree Celsius. Lower than PTT. Once the power goes off the logic sensing device senses the permitted range of battery discharged voltage and permitted room temperature. One the threshold is reached as per TBP then it starts generator or other power backup device. This logic along with phase change material (PCM) provides diesel generator running saving. In the area, where power is not connected, this solution helps to minimize DG running as it gets charged in few hours of operation and again goes in off mode with temperature and voltage sensing. It starts again when threshold reaches and gets charged. The same cycle repeated and substantial amount of DG rest is achieved. For the telecom shelter specific high density polyethylene (HOPE) extruded panel used along with air circulation fan to provide full backup and uniform room temp during TBP. 2. Phase change material (PCM) use for Building Cooling/ Heating Phase change material (PCM) used for commercial and residential buildings have been designed and tested using 22 to 29 Deg Cel. this reduce air conditioning and heating need during power failure. The other option to use off peak power during night, charge the phase change material (PCM) by heat or cooling and maintain the temperature during day time. This improves the power utilization of the grid which is wasted during night, when there is no demand. This also reduces air conditioning cost for the user, using cheap night time power. The phase change material (PCM) is charged at 1 to 4 Deg Cel lower than PTT and discharged 1 to 4 Deg Cel higher than TBP. Other Applications - 1. Phase change material (PCM) also used to absorb ambient temperature once it is lower than phase change material (PCM) threshold temperature (28 - 30 Deg Cel) for house, telecom shelter & electronic enclosure and maintain required temperature whenever outside temperature is higher than phase change material (PCM) threshold temperature (30 Deg Cel) to avoid further air conditioning. 2. Phase change material (PCM) filled in Al foil coated with PE can be used in jackets for maintaining body temperature during extreme cold or hot between 28 - 30 Deg Cel.. phase change material (PCM) maintains the body temperature as per TBP. This is further useful for fire fighting and defence use during extreme cold or hot weather. 3. Phase change material (PCM) invention will also works to store off peak electricity of the night time in form of thermal energy using boiler and geyser in night time, while use the same energy or hot water in day time. Advantages: • The invention helps to avoid diesel gen. running for telecom shelter application as mentioned above by using sufficient battery & phase change material (PCM) backup to cater maximum power failure along with PCM - DG management circuitry . This reduces operation & maintenance cost. • It also smoothens for residential & commercial buildings temperature variation using ambient cooling. • This solution also helps to utilize off peak power energy to reduce load on peak demand time, which reduces peak demand, hence less power cuts and improves load factor by utilizing surplus power of night. • The solution provides effective method to take care of perishable item during machine like DG/ refrigeration failure. • The solution provides effective method to take care of telecom equipment during machine like DG/ air conditioner failure. • Covering batteries with the present invention phase change material (PCM) hold them at fairly constant operating temperature (25 - 35 Deg Cel) and thus improving their effective operating life. I/We claim 1. A Phase Change Material composition comprising at least 85% by weight of a calcium chloride hexa hydrate, at least 0.1% by weight of strontium or its compounds as herein described and 0-15% by weight of borax or its compounds.

Documents:

1074-del-2005-1-Petition Others-(23-08-2012).pdf

1074-del-2005-abstract.pdf

1074-del-2005-claims.pdf

1074-del-2005-correspondence-others.pdf

1074-DEL-2005-Correspondence-PO-(23-12-2009).pdf

1074-del-2005-correspondence-po.pdf

1074-del-2005-description (complete).pdf

1074-DEL-2005-Form-1-(23-12-2009).pdf

1074-del-2005-form-1.pdf

1074-del-2005-form-13.pdf

1074-del-2005-form-18.pdf

1074-del-2005-form-2.pdf

1074-del-2005-form-26.pdf

1074-del-2005-form-3.pdf

1074-del-2005-form-5.pdf

1074-del-2005-form-9.pdf

1074-del-2005-pa.pdf

1074-del-2005-Petition Others-(23-08-2012).pdf

1074-del-2005-petition-138.pdf