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 .- 67 . (canceled) 
     
     
         68 . A PCM-HTF heat exchanger apparatus for heat transfer between a phase change material bank and a heat transfer fluid comprising:
 an insulated enclosure containing alternating layers of phase change material or phase change material composite or phase change material/composite in a matrix or honeycomb of fins made of for example but not limited to metal or graphite or conductive plastic; and   formed or shaped heat exchangers made of a material for example but not limited to copper, aluminium or steel, plastic or metalized film; wherein   the said material is shaped or formed by for example but not limited to applying a thin film over or vapour deposition onto a form or directly to a layer of solid phase change material/composite, or pressing, stamping or moulding said material; wherein   the formed heat exchangers are formed to provide a network or networks of discrete branching or non-branching, independent or connected, crossing or non-crossing channels to carry one or more independent heat transfer fluids.   
     
     
         69 . A PCM-HTF heat exchanger apparatus as in  claim 68 , wherein at least one layer of heat exchanger comprises two formed heat exchangers attached back-to-back with a flat plate interposed creating separate channels on either side of the flat plate. 
     
     
         70 . A PCM-HTF heat exchanger apparatus as in  claim 68 , wherein different heat exchanging layers or channels of the apparatus supplies different services. 
     
     
         71 . A PCM-HTF heat exchanger apparatus as in  claim 68 , wherein the formed heat exchangers are applied to a phase change material or phase change material composite layer that has been pre-formed with the same pattern of channels. 
     
     
         72 . A PCM-HTF heat exchanger apparatus as in  claim 68 , wherein the phase change material layer reduces in thickness in the direction of flow of at least one heat transfer fluid in order to provide, when discharging, simultaneous or near-simultaneous heat depletion of all phase change material in contact with a given series of heat exchanger channels. 
     
     
         73 . A PCM-HTF heat exchanger apparatus as in  claim 68 , wherein the network or networks of channels form patterns on several scales, for example but not limited to:
 long wavelength sinusoidal displacement in one, two or three dimensions; and/or   deep narrow groove indentations in the phase change material or phase change material composite layer running broadly parallel to the flow direction; and/or   small scale patterns, for example, but not limited to: ridges, bumps, fins or grooves in spiral, linear, herring-bone, crossed, pseudo-random or aperiodic patterns.   
     
     
         74 . A PCM-HTF heat exchanger apparatus as in  claim 68 , wherein at least one phase change composite layer is constructed by forming the said layer's shape from a selected density of expanded natural graphite; wherein said forming step comprises for example but not limited to machining a pre-formed slab of expanded natural graphite of the said density, or preforming expanded natural graphite during its manufacture to the correct shape and density using a shaped press, or compressing low-density expanded natural graphite in-situ during the construction of the heat exchanger; and wherein phase change material is infiltrated into gaps within the expanded natural graphite before, during or after construction. 
     
     
         75 . A PCM-HTF heat exchanger apparatus as in  claim 68 , wherein magneto-calorific material is integrated into the heat exchanger either by:
 at least one phase change composite layer comprises phase change material mixed with a thermal conductivity enhancer and a magneto-calorific material; and/or   magneto-calorific material attached to at least one heat exchanger;   wherein heat is pumped to/from each bank by controlling the movement of magnets or application of magnetic fields.   
     
     
         76 . A PCM-HTF heat exchanger apparatus as in  claim 68 , wherein the heat exchange comprises one or more void spaces positioned at one or several sides of the layered structure or set of tubes and equipped with holes, slots or other arrangements to allow heat transfer fluid to flow between the void and the channels and tubes of the heat exchanger apparatus. 
     
     
         77 . A heat exchanger apparatus as in  claim 68 , wherein the channels in the heat exchanger are configured in a biomimetic network; wherein
 external tubes of a given diameter extend directly to one or more main arterial channels of the same diameter; and   each arterial channel tapers in size as it passes deeper into the PCM composite; wherein ⋅ each arterial channel splits in a sequence of branching steps to the smallest diameter; wherein   the smallest diameter channels progressively join together to form larger and larger channels finally forming one or more large vein channels exiting the PCM or PCM composite to a pipe connector.   
     
     
         78 .- 82 . (canceled) 
     
     
         83 . A PCM-HTF heat exchanger apparatus as in  claim 68 , comprising:
 a PCM-HTF heat exchanger encircles an air-HTF fin-tube heat exchanger in front of or behind which is mounted a fan; wherein   at least one Tubes form continuous paths passing alternately through the PCM-filled and air-filled regions of the heat exchanger.   
     
     
         84 . (canceled) 
     
     
         85 . A combined thermal energy store and thermal energy collector/radiator apparatus as in  claim 68 , wherein the thermal store controls the flow rate and circulation path of the heat transfer fluid from a heat source, for example but not limited to solar thermal panels;
 by measuring the external energy input to the heat source, including but not limited to solar irradiance falling on the heat source, or measuring the temperature of the heat source; and   directing the heat transfer fluid at the controlled rate to a chosen PCM bank or banks.   
     
     
         86 . A thermal energy store apparatus as in  claim 85 , wherein the irradiance is indirectly measured through measurement of the heat transfer fluid at the exit point of the heat source and the heat transfer fluid flow rate. 
     
     
         87 . A thermal energy store apparatus as in  claim 85 , wherein the flow rate and/or circulation path of the heat transfer fluid are chosen to return the heat transfer fluid to the heat source at a temperature selected to enhance thermodynamic efficiency of the heat source. 
     
     
         88 . A thermal energy store apparatus as in  claim 87 , wherein the heat source, comprising thermally isolated segments; wherein the heat transfer fluid passes sequentially through segments of the heat source; wherein the heat imparted by the heat transfer fluid to each segment sequentially increases through thermally isolated segments. 
     
     
         89 . A thermal energy store apparatus as in  claim 85 , wherein the heat source is a solar thermal energy source. 
     
     
         90 . A PCM-HTF heat exchange apparatus as in  claim 68 , 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 specific 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. 
     
     
         91 . A PCM-HTF heat exchanger apparatus as in  claim 90 , 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. 
     
     
         92 . A PCM-HTF heat exchanger apparatus as in  claim 90 , 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.   
     
     
         93 . A PCM-HTF heat exchanger apparatus as in  claim 89 , wherein the PCM-HTF heat exchanger apparatus comprises one or more channels formed of:
 Tubes or equivalent presenting, in cross-section, a spiral arrangement spiralling 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.