Energy storage systems

Abstract

There is herein described energy storage systems. More particularly, there is herein described thermal energy storage systems and use of energy storable material such as phase change material in the provision of heating and/or cooling systems in, for example, domestic dwellings.

1 - 93 . (canceled) 
     
     
         94 . A phase change material and heat transfer fluid (PCM-HTF) heat exchanger apparatus;
 wherein the phase change material (PCM) is capable of undergoing at least one energy absorbing and/or releasing phase transition at one or more temperatures and wherein each phase transition is associated with a change in the physical and/or chemical properties of said thermal energy storage material; and   wherein the PCM-HTF heat exchanger apparatus was originally constructed and/or designed and/or optimized to function as, and/or is based closely on prior art designs for, a gas to heat transfer fluid (gas-HTF) heat exchanger,   and wherein, in at least one void or channel in the gas- HTF heat exchanger, phase change material or PCM composite fills said void or channel replacing gas; and wherein all paths by which gas formerly flowed between an outer environment and the now phase change material-filled void(s) or channel(s), are sealed off,   such that phase change material, when liquid, will not flow away, and the exchange of water vapor and other trace gases between the phase change material and an outer environment is controlled.   
     
     
         95 . A phase change material and heat transfer fluid (PCM-HTF) heat exchanger apparatus as in claim  1 , wherein at least one tube carrying heat transfer fluid is replaced by a heat pipe. 
     
     
         96 . A PCM-HTF heat exchanger apparatus as in  claim 94 ,
 wherein the heat exchanger is internally divided by insulation into two or more compartments; wherein each compartment contains a different phase change material or phase change material composite with a different phase transition temperature.   
     
     
         97 . A PCM-HTF heat exchanger apparatus as claimed in  claim 96 , wherein phase change material or phase change material composite of different phase transition temperatures are thermally isolated by replacing one or more fins and/or volume of phase change material composite with insulating material. 
     
     
         98 . A PCM-HTF heat exchanger apparatus as in  claim 96 , wherein the heat pipes and/or tubes are equipped with heat pipe switching or diode arrangements or insulated pipe sections to prevent uncontrolled heat flow from hotter to colder phase change material compartments. 
     
     
         99 . A PCM-HTF heat exchanger apparatus as in  claim 94 , wherein two or more independent circuits (ports) are present within the same heat exchanger; wherein each port consists of one or more tubes/pipes or one or more heat pipes connected to one or more external services; and wherein the number of pipes/tubes and/or heat pipes of a given port, and the number of times they traverse the heat exchanger, and the size or capacity of the associated flattened or un-flattened tubes/pipes and/or heat pipes is dependent on the requirements of the services associated with said given port, and wherein the more than one ports traversing the heat exchanger are evenly spaced such that the average distance between the tube or heat pipe centers for a given port is close to equal in all directions. 
     
     
         100 . A PCM-HTF heat exchanger apparatus as in  claim 94 , wherein at least one heat transfer fluid is a two phase liquid, or a refrigerant. 
     
     
         101 . A PCM-HTF heat exchanger apparatus as in  claim 100 , wherein the heat transfer fluid used to carry heat between a PCM-HTF heat exchanger and one or more service heat exchangers acts at the same or another time as the working fluid of a heat pump between a given bank and one or more other banks. 
     
     
         102 . A PCM-HTF heat exchanger apparatus as in  claim 100 , wherein the heat pump compressor associated with a given bank serves an alternative duty, at times when there is no heat pumping to/from said given bank, as the circulation pump for the heat transfer fluid in said given bank; and wherein at the same times the expansion valves are by passed or opened or otherwise modulated to prevent heat pumping behavior. 
     
     
         103 . A method of constructing a phase change material and heat transfer fluid (PCMHTF) heat exchanger apparatus as described in  claim 94 , wherein the phase change material in a liquid state is poured via an aperture into void spaces of a gas-HTF heat exchanger; and/or wherein the liquid phase change material is poured into the enclosure under vacuum or reduced pressure. 
     
     
         104 . A method for constructing a PCM-HTF heat exchanger as in  claim 94 , wherein liquid phase change material, or liquid or semi-liquid phase change material composite, is laid down in an alternating sequence of layers between the fins of a fin-tube heat exchanger, or in a sequence of layers around the tubes of a tube heat exchanger; and
 wherein the said phase change material or composite in each layer is applied in a precisely measured quantity and pattern; and said phase change material/composite is tamped down between each layer application.   
     
     
         105 . A method for constructing a PCM-HTF heat exchanger as in  claim 94 , wherein a solid phase change material or phase change material composite block is cast, formed or drilled with a given hole pattern and pushed home in sequence with fins or tubes of a fin-tube or tube heat exchanger, and wherein the tubes are specially prepared with thermal grease and/or graphite and/or with a pattern of small longitudinal fins to provide adequate thermal contact with the phase change material after tube expansion. 
     
     
         106 . A PCM-HTF heat exchange apparatus as in  claim 94 , wherein the distribution of phase change material or phase change material composite around a tube or equivalent is not held constant;
 wherein the distribution is designed to ensure that all along the tube, when discharging, the time when the heat of the PCM is depleted is broadly the same along a portion of or the majority of the tube;   wherein the PCM-HTF exchanger geometry is such that the amount of PCM associated with each section along the tube is scaled by the power related to that section, and   wherein the distribution of phase change material to a given tube or equivalent tapers, associating a larger amount of PCM with a tube or equivalent near the entrance of the heat transfer fluid to a smaller amount towards the end of the tube's or equivalent's path through the PCM.   
     
     
         107 . A PCM-HTF heat exchanger apparatus as in  claim 94 , wherein the distribution of phase change material or phase change material composite is also dependent on:
 distance that the heat must travel through the PCM, PCM composite or fin in the system; and/or   the specific heat of any fins, the thermal conductivity enhancer or PCM and latent heat of elements of the system.   
     
     
         108 . A PCM-HTF heat exchanger apparatus as in  claim 94 , wherein the PCM-HTF heat exchanger apparatus comprises one or more channels formed of:
 tubes or equivalent presenting, in cross-section, a spiral arrangement spiraling out from a central tube, with each alternate tube running in the opposite direction to the preceding tube, with spacing between tubes on the spiral increasing along the spiral path in a logarithmic way, and heat transfer fluid starting from the outermost tube and ending at the central tube; and/or   several rows of tubes, with decreasing vertical spacing between successive rows in the direction of heat transfer fluid flow, with each successive row containing more tubes spaced closer together; wherein every alternate tube runs in opposite directions; and/or   thick layers of PCM or PCM composite with widely spaced channels for HTF moving to thin layers of PCM or PCM composite with closely spaced channels in the direction of heat transfer fluid flow; and/or   a water tank filled with metal or plastic spheres encapsulating PCM arranged in layers with larger spheres at the bottom of the tank and progressively reducing size in successive layers up the tank in which water flows in at the bottom and out at the top.   
     
     
         109 . The phase change material and heat transfer fluid (PCM-HTF) heat exchanger apparatus of  claim 94 , wherein the heat exchanger is a fin-tube heat exchanger or a car-radiator. 
     
     
         110 . The phase change material and heat transfer fluid (PCM-HTF) heat exchanger apparatus of  claim 94 , wherein the all paths by which gas formerly flowed between an outer environment and the now phase change material-filled voids or channels, are sealed off by sealing the entire heat exchanger within an outer enclosure. 
     
     
         111 . The phase change material and heat transfer fluid (PCM-HTF) heat exchanger apparatus of  claim 96 , wherein the arrangement of said compartments relative to the arrangement of pipes, tubes or heat pipes, ensures that the flow of HTF in pipes or tubes, or successive locations along a heat pipe, pass through compartments in strictly increasing or strictly decreasing order of phase transition temperatures. 
     
     
         112 . The method of constructing a phase change material and heat transfer fluid (PCMHTF) heat exchanger apparatus as described in  claim 103 , wherein said liquid phase change material is poured into a partially enclosed fin-tube heat exchanger from one edge and fills all spaces between fins via gravity. 
     
     
         113 . The method for constructing a PCM-HTF heat exchanger as in  claim 104 , wherein said tamping action in a fin-tube heat exchanger is performed by the next fin being applied; and wherein in a tube heat exchanger said tamping action is performed by a plate equipped with a given pattern of holes allowing it to slide over, or alternatively between, the tubes, said plate being withdrawn after each tamping action.