System and method for storing seasonal environmental energy

Abstract

One embodiment of the invention is a thermosiphon vessel for storing seasonal environment energy in the ground. The thermosiphon includes: a fluid vessel comprising a heat exchange tube, configured to contain a working fluid, and further configured to receive a fluid inlet and a fluid outlet; a wicking material arranged within the fluid vessel and configured to retain liquid-state working fluid substantially adjacent an inner wall of the heat exchange tube; a fluid level sensor arranged within the fluid vessel and configured to determine the level of liquid-state working fluid therein; and a pump arranged within the fluid vessel and configured to maintain the level of liquid-state working fluid below a threshold level within the fluid vessel. The pump is operable between an energy capture mode to absorb thermal energy from an above-ground heat source and an energy release mode to release thermal energy to an above-ground heat sink.

We claim: 
     
         1 . A system for storing seasonal environment energy for temperature regulation of a structure, the system comprising:
 a fluid vessel including a heat exchange tube and a bottom, configured to be installed in the ground, and to contain working fluid;   a reservoir coupled to the fluid vessel and configured to store working fluid;   a heat exchange system comprising:
 an indoor heat exchanger configured to communicate thermal energy between working fluid and an interior volume of the structure; and 
 an outdoor heat exchanger configured to communicate thermal energy between working fluid and the environment; 
   a pump configured to displace fluid from the fluid vessel to the reservoir to maintain the level of liquid-state working fluid below a threshold level within the fluid vessel, the pump operable between:
 an energy capture mode, wherein the pump displaces liquid-state working fluid from the fluid vessel to a portion of the heat exchange system, wherein the heat exchange system communicates thermal energy into the working fluid and the fluid vessel communicates the thermal energy into the ground for storage; and 
 an energy release mode, wherein working fluid is displaced from the fluid vessel to a portion of the heat exchange system, wherein the fluid vessel communicates thermal energy stored in the ground into the working fluid and the heat exchange system communicates the thermal energy out of the working fluid. 
   
     
     
         2 . The system of  claim 1 , further comprising a second fluid vessel configured to be installed in the ground proximal the fluid vessel and further comprising a second pump configured to displace fluid from the second fluid vessel to the reservoir to maintain the level of liquid-state working fluid within the fluid vessel, the second pump operable between:
 an energy capture mode, wherein the second pump displaces liquid-state working fluid from the second fluid vessel to a portion of the heat exchange system, wherein the heat exchange system communicates thermal energy into the working fluid and the second fluid vessel communicates the thermal energy into the ground for storage; and   an energy release mode, wherein working fluid is displaced from the second fluid vessel to a portion of the heat exchange system, wherein the second fluid vessel communicates thermal energy stored in the ground into the working fluid and the heat exchange system communicates the thermal energy out of the working fluid.   
     
     
         3 . The system of  claim 1 , wherein an inner surface of the heat exchange tube defines a directing geometry along a portion of the length thereof. 
     
     
         4 . The system of  claim 1 , further comprising a wicking feature arranged within the fluid vessel and configured to retain liquid-state working fluid substantially adjacent an inner wall of the heat exchange tube. 
     
     
         5 . The system of Claim  4 , wherein the wicking feature is arranged along the inner surface of the heat exchange tube and is selected from the group consisting of: a porous material; a textile; a plurality of channels of substantially minimal cross section; and a plurality of ridges. 
     
     
         6 . The system of  claim 1 , wherein the reservoir is configured to store excess fluid and to be arranged above ground, wherein the pump is further configured to cycle liquid-state working fluid between the fluid vessel and the reservoir while maintaining the level of liquid-state working fluid below the threshold level. 
     
     
         7 . The system of  claim 1 , further comprising a fluid level sensor arranged within the fluid vessel and configured to determine the level of liquid-state working fluid within the fluid vessel. 
     
     
         8 . The system of Claim  7 , further comprising a processor configured to control the pump based upon an output of the fluid level sensor. 
     
     
         9 . The system of  claim 1  configured to function as a heating system, wherein, in the energy capture mode, the pump displaces liquid-state working fluid toward the outdoor heat exchanger to capture thermal energy from the environment and the fluid vessel communicates the thermal energy into the ground to generate a soil-based thermal hot battery proximal the fluid vessel, and wherein, in the energy release mode, the fluid vessel communicates thermal energy from the soil-based thermal hot battery into the working fluid and the indoor heat exchanger communicates the thermal energy from the working fluid to the interior volume of the structure. 
     
     
         10 . The system of Claim  9 , wherein the fluid vessel and the reservoir are configured to contain working fluid that comprises water. 
     
     
         11 . system of  claim 1  configured to function as a cooling system, wherein, in the energy release mode, the fluid vessel communicates thermal energy from the ground into the working fluid and the outdoor heat exchanger communicates the thermal energy from the working fluid to the environment to generate a soil-based thermal cold battery proximal the fluid vessel, and wherein, in the energy capture mode, the pump displaces liquid-state working fluid toward the indoor heat exchanger to capture thermal energy from the interior volume of the structure and the fluid vessel communicates the thermal energy into the ground. 
     
     
         12 . The system of Claim ii, wherein the fluid vessel and reservoir are configured to contain working fluid that is R-134a refrigerant. 
     
     
         13 . The system of  claim 1 , wherein the pump is configured to operate in the energy capture mode substantially during a period of substantially high environmental temperatures and to operate in the energy release mode during a period of substantially low environmental temperatures. 
     
     
         14 . The system of  claim 1 , wherein the indoor and outdoor heat exchangers are physically distinct, the indoor heat exchanger is configured to be arranged within the structure, and the outdoor heat exchanger is configured to be arranged external the structure. 
     
     
         15 . The system of  claim 14 , wherein the indoor heat exchanger comprises a heat pump. 
     
     
         16 . The system of  claim 14 , wherein the outdoor heat exchanger comprises a solar array. 
     
     
         17 . The system of  claim 1 , wherein the heat exchange system comprises a shell and tube heat exchanger and a fan configured to blow air therethrough. 
     
     
         18 . The system of  claim 1 , further comprising an external display configured to display, to a user, information regarding operation of at least one of the fluid vessel, the heat exchange system, the reservoir, and the pump. 
     
     
         19 . The system of  claim 1 , further comprising a valve configured to selectively isolate the indoor and outdoor heat exchangers from the fluid vessel. 
     
     
         20 . A method for regulating the temperature within a structure with a first thermosiphon array of fluid vessels, installed in the ground proximal the structure, and a second thermosiphon array of fluid vessels, installed in the ground proximal the structure and substantially removed from the first thermosiphon array, the method comprising:
 during a period of substantially high environmental temperatures:
 generating a thermal hot battery of the ground proximal the first thermosiphon array by directing liquid-state working fluid from the first array of fluid vessels through an outdoor heat exchanger exposed to the environment, wherein working fluid absorbs thermal energy from the environment and releases the thermal energy into the ground, proximal the first thermosiphon array, for storage; and 
 cooling the structure by directing liquid-state working fluid from the second array of fluid vessels through an indoor heat exchanger coupled to the structure, wherein working fluid absorbs thermal energy from the structure and releases the thermal energy into the ground proximal the second thermosiphon array; and 
   during a period of substantially low environmental temperatures:
 generating a thermal cold battery of the ground proximal the second thermosiphon array by directing vapor-state working fluid from the second array of fluid vessels through an outdoor heat exchanger exposed to the environment, wherein working fluid absorbs thermal energy from the ground proximal the second thermosiphon array and releases the thermal energy to the environment; and 
 heating the structure by directing working fluid from the first array of fluid vessels through an indoor heat exchanger coupled to the structure, wherein working fluid absorbs thermal energy from the ground proximal the first thermosiphon array and releases the thermal energy into the structure. 
   
     
     
         21 . The method of  claim 20 , wherein generating the thermal cold battery of the ground comprises passively pumping vapor-state working fluid out of the second array of fluid vessels. 
     
     
         22 . The method of  claim 20 , wherein generating the thermal hot battery of the ground and cooling the structure comprise actively pumping liquid-state working fluid out of the first array of fluid vessels. 
     
     
         23 . The method of  claim 20 , further comprising maintaining the level of liquid-state working fluid within each fluid vessel of the first and second thermosiphon arrays below a threshold level. 
     
     
         24 . A thermosiphon vessel for storing seasonal environment energy in the ground, the thermosiphon comprising:
 a fluid vessel comprising a heat exchange tube, configured to contain a working fluid, and further configured to receive a fluid inlet and a fluid outlet;   a wicking feature arranged within the fluid vessel and configured to retain liquid-state working fluid substantially adjacent an inner wall of the heat exchange tube;   a fluid level sensor arranged within the fluid vessel and configured to determine the level of liquid-state working fluid therein; and   a pump arranged within the fluid vessel, configured to maintain the level of liquid-state working fluid below a threshold level within the fluid vessel, and operable between:
 an energy capture mode, wherein the pump displaces liquid-state working fluid from the fluid vessel to absorb thermal energy from an above-ground heat source, wherein the fluid vessel communicates the thermal energy from the working fluid into the ground for storage; and 
 an energy release mode, wherein working fluid is directed from the fluid vessel to release thermal energy to an above-ground heat sink, wherein the fluid vessel communicates thermal energy stored in the ground into the working fluid. 
   
     
     
         25 . The method of  claim 24 , wherein the wicking feature is configured to direct working fluid toward an inner wall of the heat exchange tube by capillary action. 
     
     
         26 . The method of  claim 24 , wherein the wicking feature is a textile material retained against the portion of the inner wall of the heat exchange tube by a coil spring. 
     
     
         27 . The method of  claim 24 , further comprising a directing geometry arranged along a portion of an inner wall of the heat exchange tube. 
     
     
         28 . The method of  claim 27 , wherein the directing geometry comprises one or more features selected from the group consisting of: a ridge, a cup, a prong, a shelf, and a perforated sheet. 
     
     
         29 . The system of  claim 24 , wherein the fluid vessel further comprises an interface cap transiently coupled to the top of the heat exchange and configured to receive the fluid inlet and the fluid outlet. 
     
     
         30 . The system of  claim 29 , wherein the fluid vessel further comprises an integration cap coupled to the bottom of the heat exchange tube, opposite the interface cap, and configured to retain the pump.