The present invention relates generally to geothermal cooling systems, and more particularly to a geothermal cooling device coupled with a superconducting heat transfer element for use as an air conditioner.
Ground source heat pump systems, also known geothermal or geoexchange systems, have been used for heating and cooling buildings for more than half a century. In 1993, the Environmental Protection Agency evaluated all available heating and cooling technologies and concluded that ground source heat pump systems were the most energy efficient systems available in the consumer marketplace.
Conventional ground source heat pump systems operate on a simple principle. In the heating mode they collect heat energy from the ground and transfer it to a heat pump, which concentrates the heat and transfers it to a building's heat distribution system which in turn heats the building. In the cooling mode, heat from the building is collected by the cooling system and transferred to the heat pump, which concentrates the energy and transfers it to a ground source loop, which transfers the heat to the ground. In both modes, only a small amount of the heat comes from the electricity that runs the compressor; most of the heating and cooling energy comes from the ground. This allows ground source heat pump systems to achieve more than 100% efficiency: every unit of electrical energy consumed by the heat pump produces more useable heat than an electrical resistance heater can produce with the same unit of electricity.
Even though ground source heat pump systems achieve efficiencies of up to 350% compared to less than 100% for many conventional systems, they have been slow to penetrate the consumer marketplace because of high capital costs, high installation costs, difficult installation procedures and low energy cost savings due to historically low energy prices.
These high capital and installation costs have largely been due to fundamental inefficiencies in the ground loop subsystem. In a typical installation, the ground loop consists of hundreds or thousands of feet of looped plastic piping buried in deep trenches or deep holes drilled into the ground. An antifreeze solution is pumped through this loop to absorb heat energy from the ground (in the heating mode) or transfer heat energy to the ground (in the cooling mode.) Few installations have sufficient available land for trenching so loops are most commonly installed in deep holes and this makes them relatively expensive for several reasons.
First, each loop consists of a supply and return line, which should fit down the same hole. With an outer diameter of an inch or more for each pipe and a tendency for these pipes to bow away from each other due to the plastic material's memory of being coiled for shipment, the hole should typically have a diameter of 4 to 6 inches to allow the loop to be installed. Holes of this size are relatively expensive to drill and require heavy equipment that disrupts landscaping, making it expensive to retrofit existing homes. Holes of this size also leave large voids around the loop that should be filled with materials such as bentonite clay in order for heat to transfer from the ground to the loop, which adds significantly to the cost of installation.
Second, having both supply and return lines in the same hole results in thermal “short circuiting” which reduces the efficiency of the loop. In the heating mode, for example, cool fluid from the heat pump absorbs heat from the ground as it goes down the supply line in the hole, cooling the ground around the pipe. When the warmed fluid comes back up the hole in the return line, it passes through the ground that was just cooled, losing some of the heat it has just picked up. This lowers the efficiency of the loop so the loop should be made longer to compensate, adding to the cost of drilling and piping.
Third, for the ground loop to function, the antifreeze solution should be pumped through hundreds or thousands of feet of small diameter piping. This consumes a significant amount of electric energy, lowering the overall efficiency of the system.
In recent years, a new ground source heat pump technology has evolved to overcome some of the inefficiencies of conventional systems. This technology, called “direct geoexchange,” replaces the conventional plastic ground loop with a small-diameter copper loop. Instead of an antifreeze solution, direct geoexchange systems pump a refrigerant through the loop to pick up heat from the ground or give off heat to the ground in the same way that conventional ground loops function.
Direct geoexchange has some significant advantages over conventional systems. First, the direct geoexchange loop runs directly to and from the heat pump's compressor, eliminating the heat exchanger that is required by conventional systems to transfer heat from the loop to the heat pump. Second, the small diameter of the direct exchange loop makes it possible for loops to be installed in smaller diameter holes in the ground; this reduces the cost of drilling and backfilling the holes and reduces the size of the drill rig required to drill the holes, decreasing damage to landscaping in retrofit applications. Third, the copper pipes used in direct geoexchange transfer heat more efficiently to and from the ground so the total length of loop required is typically less than conventional systems. Because of these improvements, direct geoexchange systems can be cheaper than conventional ground source systems and more energy efficient.
In spite of these inherent advantages, direct geoexchange also has some significant disadvantages. First, both supply and return pipes run in the same hole, so the thermal short circuit problems of conventional systems remain. Second, the loop system pumps much more refrigerant through many more feet of piping past many more connections than conventional systems, so the potential for refrigerant leaks is increased. Third, direct geoexchange requires large volumes of refrigerant to flow through the loop, behaving differently in the heating and cooling modes, and requiring additional refrigerant reservoirs and flow control systems to compensate. Because of these inefficiencies, direct geoexchange is only able to achieve a modest improvement in total energy efficiency over conventional ground source heat pump systems.
Direct geoexchange and conventional ground source heat pump systems have additional limitations. Both require a significant amount of electrical power to pump fluids through hundreds or thousands of feet of piping. This not only limits overall system efficiency but also limits the environments in which it can be installed. This kind of power is not often available or reliable in the world's developing countries, so existing ground source heat pump systems have limited potential to penetrate broad world markets. In addition, since both systems are designed to heat and cool whole buildings, neither can efficiently be installed on the incremental room-by-room basis on which most of the world adopts heating and air conditioning.
In summary, conventional geoexchange systems and direct expansion geoexchange systems have significant limitations in energy efficiency, installation cost and installation flexibility.
There is a need, therefore, for a geothermal exchange system that operates in combination with a refrigerant heat intensification loop, utilizes less power than conventional refrigerant or coolant based geoexchange systems, results in lightweight heat exchangers that can be configured in a wide range of interior locations, has an extended lifetime due to fewer parts, has reduced ground loop installation costs and provides enhanced cooling and heating efficiency compared to power used.
In one embodiment, a geothermal exchange system uses a refrigerant loop with high heat transfer superconductor couplable to an earth source. The system includes a compressor, a first heat exchanger and a second heat exchanger, each of the heat exchangers adapted to function interchangeably as an evaporator and a condenser, such that the first heat exchanger is operable as an evaporator and the second heat exchanger is operable as a condenser when the system is operating in cooling mode, and such that the first heat exchanger is operable as a condenser and the second heat exchanger is operable as an evaporator when the system is operating in heating mode, at least one first conduit in communication with the compressor and each of the heat exchangers and adapted for carrying refrigerant through the system to each of the heat exchangers, the at least one conduit including a return conduit for carrying refrigerant gas back to the compressor, a reversing valve in communication with said at least one conduit and configured to reverse the flow of refrigerant from the compressor to the heat exchangers depending upon whether the system is operating in the cooling mode or the heating mode; and at least one of either an above-ground thermal superconductor segment thermally coupled to said second heat exchanger or a thermal interconnect thermally coupled to said second heat exchanger, and thermally couplable to a thermal superconductor segment such that heat transfer losses are less than 20%.
When the system is operating in heating mode, the valve is activated to direct refrigerant pumped from the compressor through the at least one conduit to the first heat exchanger where the refrigerant gas is condensed into liquid, through the return conduit to the second heat exchanger where the liquid is vaporized into gas and heat is efficiently transferred from earth source through the thermal superconductor, and back to the compressor via the return conduit; and such that when the system is operating in cooling mode, the valve is activated to direct refrigerant pumped from the compressor through the at least one conduit to the second heat exchanger where the refrigerant gas is condensed into liquid and heat is efficiently transferred to earth source through the thermal superconductor, through the return conduit to the first heat exchanger wherein the liquid is vaporized into gas, and back to the compressor via the return conduit.
In another embodiment, a cooling device using an efficient geothermal system with a high heat transfer superconductor couplable to an earth source. The cooling device includes a compressor, a first heat exchanger and a second heat exchanger, such that the first heat exchanger is operable as an evaporator and the second heat exchanger is operable as a condenser in a cooling mode, at least one first conduit in communication with the compressor and first heat exchanger and adapted for carrying refrigerant through the system to each of the heat exchangers, the at least one conduit including a return conduit for carrying refrigerant gas back to the compressor from the second heat exchanger, and at least one of either an above-ground thermal superconductor segment thermally coupled to said second heat exchanger or a thermal interconnect thermally coupled to said second heat exchanger, and thermally couplable to a thermal superconductor segment such that heat transfer losses are less than 20%, and such that refrigerant is pumped from the compressor through the at least one conduit to the second heat exchanger where the refrigerant gas is condensed into liquid and heat is efficiently transferred to earth source through the thermal superconductor, the refrigerant transfers through the return conduit to the first heat exchanger wherein the liquid is vaporized into gas, and back to the compressor via the return conduit.
In another embodiment, a heating device using an efficient geothermal system with high heat transfer superconductor couplable to an earth source. The heating device includes, a compressor, a first heat exchanger and a second heat exchanger, such that the first heat exchanger is operable as an evaporator and the second heat exchanger is operable as a condenser in a cooling mode at least one first conduit in communication with the compressor and first heat exchanger and adapted for carrying refrigerant through the system to each of the heat exchangers, the at least one conduit including a return conduit for carrying refrigerant gas back to the compressor from the second heat exchanger, and at least one of either an above-ground thermal superconductor segment thermally coupled to said second heat exchanger or a thermal interconnect thermally coupled to said second heat exchanger, and thermally couplable to a thermal superconductor segment such that heat transfer losses are less than 20%, such that refrigerant is pumped from the compressor through the at least one conduit to the second heat exchanger where the refrigerant gas is condensed into liquid and heat is efficiently transferred to earth source through the thermal superconductor, the refrigerant transfers through the return conduit to the first heat exchanger wherein the liquid is vaporized into gas, and back to the compressor via the return conduit.
a is a schematic diagram of an efficient geothermal exchange system couplable to a superconducting geoexchange ground loop.
With reference to the drawings, new and improved heating and cooling devices and geothermal exchange systems embodying the principles and concepts of the present device will be described. In particular, the devices and systems are applicable for climate control within structures as well as more generally to bi-directional heat transfer to and from earth sources. The embodiments shown in the attached figures satisfy the need for a geothermal exchange system with improved thermal efficiency, lower installation cost and greater installation flexibility.
Recent advances in thermal superconducting materials can now be considered for use in novel energy transfer applications. For example, U.S. Pat. No. 6,132,823 and continuations thereof, discloses an example of a heat transfer medium with extremely high thermal conductivity, and is included herein by reference. Specifically the following disclosure indicates the orders of magnitude improvement in thermal conduction; “Experimentation has shown that a steel conduit 4 with medium 6 properly disposed therein has a thermal conductivity that is generally 20,000 times higher than the thermal conductivity of silver, and can reach under laboratory conditions a thermal conductivity that is 30,000 times higher that the thermal conductivity of silver.” Such a medium is thermally superconducting. In this disclosure, the term superconductor shall interchangeably mean thermal superconductor or thermal superconductor heat pipe. The available product sold by Qu Energy International Corporation is an inorganic heat transfer medium provided in a vacuum sealed heat conducting tube.
Alternate thermal superconductors may be equivalently substituted, such as thermally superconducting heat pipes. Heat pipes typically include a sealed container (pipe), working fluid and a wicking or capillary structure inside the container. Heat is transported by an evaporation-condensation cycle when a thermal differential is present between opposing ends. Working fluids can be selected with high surface tension to generate a high capillary driving force such that the condensate can migrate back to the evaporator portion, even against gravity. Some working fluids useful for the geothermal operating temperature range include ammonia, acetone, methanol and ethanol. Inside the tube, the liquid enters and wets the internal surfaces of the capillary structure. Applying heat at one segment of the pipe, causes the liquid at that point to vaporize picking up latent heat of vaporization. The gas moves to a colder location where it condenses, giving up latent heat of vaporization. The heat transfer capacity of a heat pipe is proportional to the axial power rating, the energy moving axially along the pipe. For maximum energy transfer the heat pipe diameter should be increased and the length shortened, making it operable but less preferred than a non-liquid superconductor such as the Qu product. In particular with respect to the ground loop, scaled-up heat pipe designs have been disclosed for geothermal heating applications, such as in PCT Publication No. WO 86/00124 (“Improvements in earth heat recovery systems”). These designs partially overcome the length to diameter ratio problem but preferably require a recirculation pump for the fluid. A two-way heat pipe design for ventilation heat-exchanger is disclosed in U.S. Pat. No. 4,896,716, and could be used for non-ground loop transfer as a two-way thermal superconductor.
In the preferred case, the depth of hole D is selected in combination with the thermal transfer properties of the thermal superconductor element, the thermal transfer properties of the ground around hole D and the maximum expected rate of heat transfer between the heating/cooling system and the ground, in order to provide a desired heating and cooling capacity for the system. As in conventional geoexchange systems, the depth of hole 50 may be greater than is practicable for a single hole, so a plurality of holes may be substituted to receive a plurality of geothermal heat exchange elements with an aggregate depth equal to or greater than the required depth of a single hole. As shown in
The superconductor segment 40 extends in an uninsulated portion 42 to be in thermal contact with a heat exchange segment 68 of a refrigerant loop that functions to circulate heat transferred to and from the ground loop, as shown in ground loop heat exchanger 66. The refrigerant loop circuit forms a refrigerant transfer path which includes a compressor 20 having outlet connected to refrigerant conduit 22 to a reversing valve 28 through conduit 32 to a heat exchange segment 38 in space heat exchanger 36 to a conduit 60 connected to a directional expander 62 with conduit 64 to a ground heat exchanger 28 connected to a return conduit 34, through the reversing valve 28 to conduit 21 and an optional accumulator 23 to a return conduit 24 to the inlet of the compressor 20. Persons familiar with the technology involved here will recognize that the space heat exchanger or ground heat exchanger are interoperable as condenser or evaporator heat exchangers to provide heating or cooling modes as the reversing valve 28 is switched from a first position to a second position.
When the refrigerant loop as described is filled with a suitable amount of refrigerant, the compressor can be powered on to operate the refrigerant heat exchange circuit. In a heating mode example of the flow of refrigerant, the compressor 20 compresses a gaseous refrigerant to intensify its heat content, circulates it through conduit 22 to the space heat exchanger 38 which acts as a condenser causing the gaseous refrigerant to condense to a liquid (or partial liquid) before passing through conduit 60 to expander 62 which rapidly expands the liquid in a pressure drop to change the refrigerant state to cooled vapor which absorbs heat at the evaporator heat exchanger 68 from the ground loop before passing through return conduit 34 to optional accumulator 23 (where remaining liquid is trapped and vaporized) after which the remaining refrigerant transfers through conduit 24 to complete the loop at the compressor inlet. This creates a temperature differential between space heat exchanger 38 and ground heat exchanger 68. In the preferred case, the refrigerant heat exchangers are isolated by insulation 25 as shown. The reversing valve 28 functions to direct the refrigerant flow in alternate directions, which reverses the thermal function of the heat exchangers becoming condenser and evaporator in open mode and evaporator and condenser in closed mode respectively. A thermal sensor 26 is associated with the medium to be conditioned by space heat exchange coil 38. A controller 16 is powered by power line 14 and provides power to compressor 20 through control line 18 and reversing valve 28 through control line 30, as well as control data to and from thermal sensor 26. Space heat exchange coil 38 can be configured in any suitable geometric arrangement related to a structure to improve or optimize heat transfer to a specific medium. Insulation 25 also preferably covers superconductor transfer segments outside of coupling connections and heat exchange sections, to reduce thermal transfer losses.
The superconductor geothermal exchange system 110 is operated in either a heating or cooling mode depending on the difference between the actual measured temperature and a desired set-point programmed in the thermostatic controller 16. For example, when the desired temperature is higher than actual temperature the superconductor geothermal exchange system 110 is operated in a heating mode. In heating mode, reversing valve 28 is opened such that space heat exchanger 38 operates as a condenser giving off heat and ground heat exchanger 68 operates as an evaporator receiving heat from ground link superconductor 40, while controller 16 operates compressor 20. Heat is then efficiently transferred from ground loop 48 to the ground heat exchanger 68, then efficiently transferred through the refrigerating loop to space heat exchanger for related heating use. In the cooling mode example, when the desired temperature is lower than actual temperature, the superconductor geothermal exchange system 110 is operated in a cooling mode. In cooling mode, reversing valve 28 is closed such that space heat exchanger 38 operates as an evaporator receiving heat and ground heat exchanger 68 operates as a condenser giving off heat to ground link superconductor 40, while controller 16 operates compressor 20. Heat is then efficiently transferred from space heat exchanger 68 to ground loop 48 for related cooling use. The modes may simply switch on/off rather than oscillate between heating and cooling based on controller programming and averaging forecasting.
The refrigerant loop circuit may have additional components as required to scale for larger energy applications. As known in the art of conventional heat pump systems, such larger systems may have receivers, suction accumulators, bulb sensors, thermostatic expansion metering valves and the like to manage refrigerant flow through the circuit.
The superconductor geothermal exchange system 110 attached to segment 40 above coupler 44 can be enclosed a number of ways, depending on application. For example, the components shown could be housed inside one enclosure 12.
As will be apparent to persons familiar with the technology involved here, the coupler 44 could equivalently be alternatively positioned under the ground, above ground outside a structure, inside a structure but outside the housing 12, or even inside the housing 12, as selected for best ease of installation. Housing 12 may include ambient vents for convective cooling of the compressor. A further embodiment of the superconductor geothermal exchange system 110 can eliminate the coupler 44 by configuring the switch to have a ground loop receptacle to accept the termination of the superconductor ground loop 48 such that the ground loop 48 can be separately installed from the rest of the system.
By changing the ground loop from a conventional fluid loop to a superconductor element, geoexchange system 110 eliminates the energy required to circulate ground loop fluids and as a result uses less power to operate, making it possible for new improved components to be utilized. For example, a low power compressor can be used, such as is available from Danfoss Corporation. In one embodiment the low power compressor 20 can have power less than 4500 W. In an alternate embodiment the low power compressor 20 requires power less than 1800 W, making it suitable for common North American household outlets, resulting in more convenient installation that conventional systems requiring higher power.
The superconductor geothermal exchange system 110 may operate from conventional AC grid power, or, alternatively, from a DC power source such as a hydrogen fuel cell, a solar cell array, or a wind turbine or the like. In either AC or DC power embodiments, individual components may be AC or DC powered, with power conditioners provided as required (not shown), being delivered to the system 110 already conditioned externally or delivered requiring additional conditioning, as will be apparent to persons familiar with the technology involved here. In the DC powered embodiment in which the components operate on a single voltage of DC power, low voltage alternative energy power may be used directly, without power conditioning, thereby reducing energy loss and potentially eliminating the need for power conditioning devices.
Using the preferred thermal superconducting tubes, it is preferred to have insulation along the length of the superconductor segments except heat exchanger coil segments or thermal transfer couplings to other components, to limit heat loss and condensation buildup. However alternate thermal superconductor embodiments may have integrated insulating layers or have acceptable transfer loss such that the superconductor geothermal exchange system 110 is operable.
The superconductor geothermal exchange system 110 of
The controlled operation of the superconductor geothermal exchange system 120 is important for user comfort and control of heating and cooling. Controller 16 may be programmed as a thermostat controller responding to a temperature sensor 26 (such as a thermocouple) associated with the space to be heated or cooled, or as a controller that receives input from a remote thermostat and sensor associated with the space (not shown). The controller is shown within the housing 12, but may alternatively be in any suitable location provided it is in communication with the blower and temperature sensor. While the simplest implementation is one temperature measurement, to persons familiar with the technology involved here, multiple temperature measurements could be weighted or averaged for the purpose of feedback set points in the controller 16. In the case of a multi-speed fan, alternatively a second temperature sensor could be positioned on or near the space heat exchanger 38 to determine the initial fan speed for faster cooling. Unlike conventional central geothermal heat pumps, which are large, noisy and require greater power than available from a standard household outlet, the air exchange subsystem in enclosure 60 can be operated from a standard power outlet, anywhere in the house, quietly and in a small form factor housing. The housing 60 for air exchange subsystem, may be positioned anywhere within the interior room to be cooled or heated, and does not have to be near an exterior wall or window. Preferably the housing is positioned to provide optimum air mixing and heating for the room.
Operating modes are similar to those described for
A further embodiment of the superconductor geothermal exchange system 120 can eliminate the coupler 44 by configuring the switch to have a ground loop receptacle portion to accept the termination of the superconductor ground loop 48, such that the ground loop 48 can be separately installed from the rest of the system. Persons familiar with the technology involved here will recognize that that there are many equivalent designs to couple the ground loop superconductor to the switch including intermediate coupler segments.
The superconductor geothermal exchange systems of
The superconductor geothermal exchange system 110 of
The above-ground components of the geothermal exchange systems described in FIGS. 1 to 6 can be grouped in plurality of separate housings as shown in
The superconductor segment 40 extends to be in thermal contact to an evaporator exchanger 68 of a refrigerant loop that functions to circulate heat transferred from the ground loop. The refrigerant loop circuit forms a refrigerant transfer path which includes a compressor 20 having outlet connected to refrigerant conduit 22 to condenser heat exchanger 74 to a conduit 32 connected to an expander 62 with conduit 64 to evaporator heat exchanger 72 connected to a return conduit 34, through an optional accumulator 23 to a return conduit 24 to the inlet of the compressor 20.
When the refrigerant loop as described is filled with a suitable amount of refrigerant, the compressor may be powered on to operate the refrigerant heat exchange circuit. In a the heating mode, the compressor 20 compresses a gaseous refrigerant to intensify its heat content, circulates it through conduit 22 to the condenser heat exchanger 74 where the hot refrigerant vapor gives up heat and condenses to a liquid or partial liquid before passing through conduit 60 to expander 62 where the liquid refrigerant is expanded in a pressure drop to change state, becoming cooled vapor which enters evaporator heat exchanger 72 and absorbs heat from the ground loop before passing through return conduit 34 to optional accumulator 23 (where remaining liquid is trapped and vaporized) before the refrigerant transfers through conduit 24 to complete the loop at the compressor inlet. This creates a temperature differential between the condenser heat exchanger 74 and evaporator heat exchanger 72. In the preferred case, heat exchangers 74 and 72 are isolated by insulation 25 (not shown.) A thermal sensor 26 is associated with the medium to be conditioned by condenser heat exchanger 74. A controller 16 is powered by power line 14 and provides power to compressor 20 and reversing valve 28, as well as control data to and from thermal sensor 26. Condenser heat exchanger 74 can be configured in any suitable geometric arrangement related to a structure to improve or optimize heat transfer to a specific medium. Insulation 25 also preferably covers superconductor transfer segments outside of coupling connections and heat exchange sections, to reduce thermal transfer losses.
The superconductor geothermal exchange system 150 is operable depending on the difference between the actual measured temperature and a desired set-point programmed in the thermostatic controller 16. For example, when the desired temperature is higher than actual temperature the superconductor geothermal exchange system 150 is operated. Heat is then efficiently transferred from ground loop 48 to the evaporator heat exchanger 72, then efficiently transferred through the refrigerating loop to condenser heat exchanger for related heating use.
The superconductor geothermal exchange system 150 attached to segment 40 above coupler 44 can be enclosed a number of ways, depending on application. For example, the components as shown could be housed inside one enclosure 12. Alternatively thermal superconductor segments 40 and 42 can be installed at a later time. As will be apparent to persons familiar with the technology involved here, the coupler 44 could equivalently be alternatively positioned under the ground, above ground outside a structure, inside a structure but outside the housing 12, or even inside the housing 12, as selected for best ease of installation. Housing 12 may include ambient vents for convective cooling of the compressor. A further embodiment of the superconductor geothermal exchange system 150 can eliminate the coupler 44 by configuring the switch to have a ground loop receptacle to accept the termination of the superconductor ground loop 48 such that the ground loop 48 can be separately installed from the rest of the system.
The superconductor geothermal heating device 150 of
The controlled operation of the superconductor geothermal exchange system 160 is important for user comfort and control of heating. Controller 16 may be programmed as a thermostat controller responding to a temperature sensor 26 (such as a thermocouple) associated with the space to be heated, or as a controller that receives input from a remote thermostat and sensor associated with the space (not shown). The controller is shown within the housing 12, but may alternatively be in any suitable location provided it is in communication with the blower and temperature sensor. While the simplest implementation is one temperature measurement, persons familiar with the technology involved here will recognize that multiple temperature measurements could be weighted or averaged for the purpose of feedback set points in the controller 16. In the case of a multi-speed fan, alternatively a second temperature sensor could be positioned on or near the space heat exchanger 74 to determine the initial fan speed for faster heating. Unlike conventional central geothermal heat pumps, which are large, noisy and require greater power than available from a standard household outlet, the air exchange subsystem in enclosure 60 can be operated from a standard power outlet, anywhere in the house, quietly and in a small form factor housing. The housing 60 for air exchange subsystem, may be positioned anywhere within the interior room to be heated, and does not have to be near an exterior wall or window. Preferably the housing is positioned to provide optimum air mixing and heating or cooling for the room.
Operating mode is similar as described for
A further embodiment of the superconductor geothermal exchange system 160 can eliminate the coupler 44 by configuring the evaporator heat exchanger 68 to have a receptacle portion to accept the termination of the superconductor ground loop 48, such that the ground loop 48 can be separately installed from the rest of the system. Persons familiar with the technology involved here will recognize that that there are many equivalent designs to couple the ground loop superconductor to the switch including intermediate coupler segments.
The superconductor geothermal heating devices of
The superconductor geothermal heating device 150 of
Alternatively, as shown in
The above-ground components of the geothermal exchange systems described in FIGS. 9 to 13 can be grouped in plurality of separate housings as shown in
The superconductor segment 40 extends to be in thermal contact to a condenser exchanger 68 of a refrigerant loop that functions to circulate heat to the ground loop. The refrigerant loop circuit forms a refrigerant transfer path which includes a compressor 20 having outlet connected to refrigerant conduit 22 to a condenser exchanger 76 to a conduit 32 connected to an expander 62 with conduit 64 to an evaporator exchanger 78 connected to a return conduit 34, through an optional accumulator 23 to a return conduit 24 to the inlet of the compressor 20.
When the refrigerant loop as described is filled with a suitable amount of refrigerant, the refrigerant heat exchange circuit is operated by powering the compressor. In a cooling mode, the compressor 20 compresses a gaseous refrigerant to intensify its heat content, circulates it through conduit 22 to the condenser exchanger 76 where it gives up heat to the ground loop acting as a condenser, and then passes through conduit 60 to expander 62 which rapidly expands liquid in a pressure drop to change the refrigerant state to cooled vapor which absorbs heat at the evaporator exchanger 78 before passing through return conduit 34 to optional accumulator 23 (where remaining liquid is trapped and vaporized) and remaining refrigerant transfers through conduit 24 to complete the loop at the compressor inlet. This creates a temperature differential between evaporator exchanger 78 and condenser exchanger 76. In the preferred case, the refrigerant heat exchangers are isolated by insulation 25 as shown. A thermal sensor 26 is associated with the medium to be conditioned by evaporator exchanger 78. A controller 16 is powered by power line 14 and provides power to compressor 20 and reversing valve 28, as well as control data to and from thermal sensor 26. Evaporator exchanger 78 can be configured in any suitable geometric arrangement related to a structure to improve or optimize heat transfer to a specific medium. Insulation 25 also preferably covers superconductor transfer segments outside of coupling connections and heat exchange sections, to reduce thermal transfer losses.
The superconductor geothermal cooling device 190 is controlled depending on the difference between the actual measured temperature and a desired set-point programmed in the thermostatic controller 16. For example, when the desired temperature is lower than actual temperature the superconductor geothermal cooling device 190 is operated in a cooling mode. In cooling mode, heat is collected at the condenser exchanger, transferred through the refrigerating loop then efficiently transferred to ground loop 48 from the condenser exchanger 76, for related cooling use.
The superconductor geothermal cooling device 190 attached to segment 40 above coupler 44 can be enclosed a number of ways, depending on application. For example, the components as shown could be housed inside one enclosure 12. Alternatively thermal superconductor segments 40 and 42 can be installed at a later time. As will be apparent to persons familiar with the technology involved here, the coupler 44 could equivalently be alternatively positioned under the ground, above ground outside a structure, inside a structure but outside the housing 12, or even inside the housing 12, as selected for best ease of installation. Housing 12 may include ambient vents for convective cooling of the compressor. A further embodiment of the superconductor geothermal cooling device 190 can eliminate the coupler 44 by configuring the switch to have a ground loop receptacle to accept the termination of the superconductor ground loop 48 such that the ground loop 48 can be separately installed from the rest of the system.
The superconductor geothermal cooling device 190 of
The controlled operation of the superconductor geothermal cooling device 200 is important for user comfort and control of cooling. Controller 16 may be programmed as a thermostat controller responding to a temperature sensor 26 (such as a thermocouple) associated with the space to be heated, or as a controller that receives input from a remote thermostat and sensor associated with the space (not shown). The controller is shown within the housing 12, but may alternatively be in any suitable location provided it is in communication with the blower and temperature sensor. While the simplest implementation is one temperature measurement, persons familiar with the technology involved here will recognize that multiple temperature measurements could be weighted or averaged for the purpose of feedback set points in the controller 16. In the case of a multi-speed fan, alternatively a second temperature sensor could be positioned on or near the space heat exchanger 38 to determine the initial fan speed for faster cooling. Unlike conventional central geothermal heat pumps, which are large, noisy and require greater power than available from a standard household outlet, the air exchange subsystem in enclosure 12 can be operated from a standard power outlet, anywhere in the house, quietly and in a small form factor housing. Preferably the housing is positioned to provide optimum air mixing and cooling for the room.
Operating modes are similar as described for
A further embodiment of the superconductor geothermal cooling device 200 can eliminate the coupler 44 by configuring the condenser exchanger 76 to have a receptacle portion to accept the termination of the superconductor ground loop 48, such that the ground loop 48 can be separately installed from the rest of the system. Persons familiar with the technology involved here will recognize that that there are many equivalent designs to couple the ground loop superconductor to the switch including intermediate coupler segments.
The above-ground components of the geothermal exchange systems described in
The superconductor geothermal cooling devices of
The thermal superconductor geoexchange systems and heating and cooling devices described herein are couplable or connectable to a thermal superconductor element. The systems may be assembled from subsystems having no thermal superconductor elements, but with the addition of a superconductor heat exchange interconnect thermally coupled to ground loop heat exchanger 68, 72 or 76. The heat exchange interconnect preferably limits increases in heat transfer resistance to less than 15% when connected to a thermal superconductor, and is easily coupled to a tube or rod shaped thermal superconductor.
Examples of such interconnections are shown in
In these examples and embodiments described, insulation has been shown on superconductor segments which function to transfer heat internally from one location to another, and insulation is not shown on ends of these segments which function to transfer heat to air, fluids or other or other system components. This is the preferred example, whether or not explicitly stated in figure descriptions or numbered on drawings. However, as noted previously, the superconductor geothermal cooling devices described will operate with no insulation or with some transfer lines insulated or combinations of insulated or uninsulated portions of the superconductors thereof.
In these examples housing has been described as split housing in a preferred case, however it will be appreciated that the various embodiments can be integrated into existing structures or enclosed in a single housing.
Although particular embodiments of the invention have been described by way of example, it will be appreciated that additions, modifications and alternatives thereto may be envisaged. The scope of the present disclosure includes any novel feature or combination of features disclosed therein either explicitly or implicitly or any generalization thereof irrespective of whether or not it relates to the claimed invention or mitigates any or all of the problems addressed by the present invention. The applicant hereby gives notice that new claims may be formulated to such features during the prosecution of this application or of any such further application derived there from. In particular, with reference to the appended claims, features from dependent claims may be combined with those of the independent claims and features from respective independent claims may be combined in any appropriate manner and not merely in the specific combinations enumerated in the claims.
Number | Date | Country | Kind |
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2,526,356 | Nov 2005 | CA | national |