US20110308268A1 - Geothermal Exchange Module and a Method of use with an Augmented Water Temperature System - Google Patents
Geothermal Exchange Module and a Method of use with an Augmented Water Temperature System Download PDFInfo
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- US20110308268A1 US20110308268A1 US13/155,252 US201113155252A US2011308268A1 US 20110308268 A1 US20110308268 A1 US 20110308268A1 US 201113155252 A US201113155252 A US 201113155252A US 2011308268 A1 US2011308268 A1 US 2011308268A1
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- water
- passageway
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B30/00—Heat pumps
- F25B30/06—Heat pumps characterised by the source of low potential heat
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
- F24D3/00—Hot-water central heating systems
- F24D3/18—Hot-water central heating systems using heat pumps
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24T—GEOTHERMAL COLLECTORS; GEOTHERMAL SYSTEMS
- F24T10/00—Geothermal collectors
- F24T10/10—Geothermal collectors with circulation of working fluids through underground channels, the working fluids not coming into direct contact with the ground
- F24T10/13—Geothermal collectors with circulation of working fluids through underground channels, the working fluids not coming into direct contact with the ground using tube assemblies suitable for insertion into boreholes in the ground, e.g. geothermal probes
- F24T10/17—Geothermal collectors with circulation of working fluids through underground channels, the working fluids not coming into direct contact with the ground using tube assemblies suitable for insertion into boreholes in the ground, e.g. geothermal probes using tubes closed at one end, i.e. return-type tubes
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B25/00—Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00
- F25B25/005—Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00 using primary and secondary systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
- F24D2200/00—Heat sources or energy sources
- F24D2200/11—Geothermal energy
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B10/00—Integration of renewable energy sources in buildings
- Y02B10/40—Geothermal heat-pumps
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/12—Hot water central heating systems using heat pumps
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/10—Geothermal energy
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P80/00—Climate change mitigation technologies for sector-wide applications
- Y02P80/10—Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
Definitions
- the present invention relates to a ground/water heat exchanger with optional water temperature augmentation. More specifically, the present invention is a system that improves on geothermal heat exchange and heat pump performance.
- Geothermal heat exchange is the exchange of heat between the earth mass and a working fluid. There are three principal types of geothermal systems in use.
- the closed loop water system features an extensive network of small diameter polyethylene (HDPE) piping.
- Water generally with anti freeze
- the loop systems are arranged to run either horizontal or vertical.
- Horizontal loops require large land areas and are generally 6 ft. below the surface.
- the vertical loops require 250-300 ft. deep bores. The majority of geothermal installations are of this type.
- the system offers modest material costs but is high in field labor costs.
- the proper number of spacing of heat exchange loops is a function of ground diffusivity and thermal load.
- the diffusivity of the earth mass is relatively poor. It is generally accepted that 6,000 cubic feet of earth mass is needed to support one ton of heating or cooling.
- Horizontal loop problems can include inadequate loop length or spacing resulting in less surface area or low ratio of earth volume to energy demand. This condition will exacerbate the deficiencies of horizontal loops and can lead to super freezing of the land during winter months and super heating of the land during summer months.
- Ground water usage is strictly regulated and the opportunities for open loop installations are limited.
- the design of the exchanger must allow for maximum harvesting of ground heat with a minimum of operating pressure head losses. This translates to useable bore depths of 12-40 ft. where the temperature is relatively constant.
- the appliance must be modular, low cost, and suitable for factory assembly and mass production.
- the present invention is able to address the need for a more efficient heat exchange module by introducing a cylindrical module utilizing concentric channels to effectively extract heat from the ground.
- the concentric channels within the cylindrical module utilizes the high thermal conductivity of saturated sand to effectively transfer heat from the ground to the water flowing through the module.
- the present invention takes a more direct and cost efficient track to providing supplemental energy through a direct boost to the geothermal cycle.
- the new cycle establishes, by design, a minimum allowable entry water temperature (approx. 40° F.). Whenever the EWT drops below that level, supplemental energy is called upon to raise the level of water temperature.
- the result as shown in FIG. 5 is a constant thermal output intersecting the heating load line and thermal output.
- the constant thermal output line is shown above the cross hatched area.
- the augmented EWT provides constant thermal output regardless of outside temperature. Since the heat pump remains the direct source of thermal output the transition from ordinary to augmented operation is seamless.
- the point at which the heating load line and the thermal output line intersect is termed the design point.
- the present invention allows for thermal output above and beyond the design point.
- the system offers another advantage. In heating dominant climates, the size of the geothermal field may be reduced thereby saving on initial system costs.
- FIG. 2 is a detailed view showing the top internal view of an assembled geothermal exchange module.
- FIG. 3 is a detailed view showing the bottom internal view of an assembled geothermal exchange module.
- FIG. 4 is a flow diagram of the temperature augmentation process, showing the refrigerant loop, the ground circuit, and the augmentation circuit.
- FIG. 5 is a graph showing the relationship of the thermal output with respect to outdoor temperature.
- the main goal of the ground circuit 1 is to extract heat from the earth 12 to 40 feet or more deep.
- the geothermal exchange loop 11 is connected to the temperature augmentation exchange loop 12 by the shared pipe branch 13 .
- the geothermal loop 11 comprises a plurality of geothermal exchange modules 111 .
- the geothermal exchange loop 11 is the portion of the ground circuit 1 that extracts heat from the earth through a series of the plurality of geothermal exchange modules 111 .
- each of the geothermal exchange modules 111 comprises a thin wall outer shell 112 , an inner pipe 113 , an outer passageway 116 , an inner passageway 117 , a end plate 118 , an o-ring seal 120 , and an optional tie rod 121 .
- the inner pipe 113 is positioned within the thin wall outer shell 112 in a concentric relationship.
- the positioning of the inner pipe 113 inside the thin wall outer shell 112 defines the outer passageway 116 and the inner passageway 117 .
- the outer passage way is the space defined between the walls of the thin wall outer shell 112 and the inner pipe 113 .
- the inner passageway 117 is defined by the space traversing through the inner pipe 113 .
- the inner passage way and the outer passageway 116 are sealed by means of the end plate 118 .
- the end plate 118 is engaged to the top end of the thin wall outer shell 112 and the inner pipe 113 to seal the inner passageway 117 and the outer passageway 116 .
- the outer passageway 116 is isolated from the inner passageway 117 .
- the optional tie rod 121 is traversed through the inner passageway 117 and secures the end plate 118 to the base of the thin wall outer shell 112 .
- the end plate further comprises of a seal groove 119 .
- the seal groove 119 is a recessed groove positioned peripherally about the end plate.
- the o-ring seal 120 is positioned in between the seal groove 119 and the thin wall outer shell 112 to fully seal the inner passageway 117 and the outer passageway 116 .
- the plurality of geothermal exchange modules 111 are connected in parallel relationship allowing water to flow into each of the inner passageways 117 for each module. The water flows out of the outer passageways 116 for each module to converge and continue through the geothermal exchange loop 11 .
- the augmentation exchange loop 12 is a parallel branch connected to the geothermal exchange loop 11 by means of the shared pipe branch 13 .
- the flow divider is positioned on a node between the augmentation loop 12 and the geothermal exchange loop 11 .
- the flow divider 131 follows the plurality of geothermal exchange modules 111 .
- antifreeze will be used with water to prevent any freezing and blockage in the ground circuit 1 .
- the use of the augmentation circuit provides for higher performance and prevents the freezing of water within the system.
- the use of an augmentation circuit is optional. With water flowing through the ground circuit 1 and the augmentation circuit 2 , water temperature is boosted as it enters the refrigerant/water heat exchanger 4 . Energy is provided and transferred to the ground circuit 1 from the augmentation circuit 2 by means of the water/water heat exchanger 5 . With heat extracted from the water at the refrigerant/water heat exchanger 4 , the water returns to the plurality of geothermal exchange modules 111 to extract heat from the ground.
- the geothermal exchange modules 111 there may be one or more module stacked in line in each bore hole.
- the modules are separated by a spacer. The spacer allows each module to maximize its harvest of heat. This has the result of minimizing the actual cylinder length while increasing the effective length per bore.
- the augmentation circuit 2 is a closed circuit system that is able to add heat energy to the ground circuit 1 through the high temperature low volume loop 21 and the low temperature high volume loop 22 .
- the water heater 211 With water flowing through the augmentation circuit, the water heater 211 provides supplementary heat to the water by means of a domestic hot water heater. In other embodiments of the present invention, the water heater 211 can provide supplementary energy through gas or solar heat. Heated water flows from the water heater towards the mixing valve 24 . The heated water flows into mixing valve 24 and enters the low temperature high volume loop 22 . The heated water is then facilitated through the low temperature high volume loops 22 by the pump 221 through the augmentation water/water heat exchanger 5 and the low temperature high volume loop 22 .
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- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
The present invention is a geothermal exchange process to deliver water, in a closed loop ground to water system, at temperatures approaching that of ground water. Such water temperatures were heretofore only achievable with ground water systems. Optimum energy saving and performance of ground coupled heat pumps are directly linked to heat exchange between a circulating water loop and ground temperature. This invention allows for the optimization of energy and performance. The efficiency of heat pumps diminishes with descending outside air temperatures. This invention allows for the manipulation of entry water temperatures to stem the problem of diminishing efficiencies. The water system makes use of a uniquely designed geothermal exchange module with increased conductivity to maximize heat transfer into the water.
Description
- The current application claims a priority to the U.S. Provisional Patent application Ser. No. 61/355,734 filed on Jun. 17, 2010.
- The present invention relates to a ground/water heat exchanger with optional water temperature augmentation. More specifically, the present invention is a system that improves on geothermal heat exchange and heat pump performance.
- Geothermal heat exchange is the exchange of heat between the earth mass and a working fluid. There are three principal types of geothermal systems in use.
- In the open loop system, water can be sourced by a pond, lake or river. Most often however; the system is sourced by an underground stream as in a well. In such circumstance the underground water temperature approximates the surrounding earth temperature. Well water is pumped to the user's location where heat is extracted (or discharged when in the cooling mode) in a water/refrigerant heat exchange and then returned to the underground through a second well. Of all the geothermal heat exchange systems the underground stream is the most energy efficient and results in the lowest operating costs. The major drawbacks to this system are environmental and financial. The use of underground water is closely regulated. Return of “waste” water with potential contamination is a concern. Financially, the cost of drilling of two deep wells makes for an expensive installation and requires wells with large throughput.
- The closed loop water system features an extensive network of small diameter polyethylene (HDPE) piping. Water (generally with anti freeze) under pump pressure, circulates underground where a heat exchange takes place and is then returned to the heat pump. The loop systems are arranged to run either horizontal or vertical. Horizontal loops require large land areas and are generally 6 ft. below the surface. The vertical loops require 250-300 ft. deep bores. The majority of geothermal installations are of this type. The system offers modest material costs but is high in field labor costs.
- Heat transfer is a function of the overall heat transfer coefficient, ground/water temperature difference and surface area. The high thermal resistance of polyethylene pipe forces a higher ground/water temperature differential resulting in lower water temperature. To improve heat transfer, water flow is ideally turbulent. Long pipe lengths with turbulent flow result in high pressure drop, thus raising operating costs. The HDPE system forces a compromise between heat transfer performance and operating costs.
- As opposed to indirect heat exchange (ground/water/refrigerant), the direct exchange (ground/refrigerant) system eliminates the intermediate heat transfer with water. In lieu of HDPE pipe, copper refrigerant piping is cased in approximately 150 ft. deep bores in a manner similar to that for HDPE pipe. The heat transfer results from a direct ground/refrigerant exchange.
- The proper number of spacing of heat exchange loops is a function of ground diffusivity and thermal load. The diffusivity of the earth mass is relatively poor. It is generally accepted that 6,000 cubic feet of earth mass is needed to support one ton of heating or cooling.
- Horizontal loops, frequently located just a few feet below frost line, are influenced by surface temperature. Ground temperature below frost line is not as is sometimes assumed at a relatively constant temperature. It is influenced by surface temperature, both summer and winter. At a depth of 12 ft. below frost line there are modest seasonal temperature variations. At a depth of 30 ft. up to several hundred feet the temperature stays constant the year around.
- According to Carnot, lower water temperature lowers heat pump efficiency . This makes the horizontal loop process inherently less efficient.
- Horizontal loop problems can include inadequate loop length or spacing resulting in less surface area or low ratio of earth volume to energy demand. This condition will exacerbate the deficiencies of horizontal loops and can lead to super freezing of the land during winter months and super heating of the land during summer months.
- Patent 2009/0165992 attempts to address the problem of inadequate earth volume and poor heat transfer by proposing a design that employs an array of heat exchange depots distributed on a basis of 10 units per ton. The invention favors a large array in a horizontal distribution and features a long liquid residence time. As a horizontal “loop” installation at an elevation just below the frost line the system cannot achieve a water temperature that is any greater than the surrounding earth; no matter how many depots are supplied. At this depth the earth temperature will be less than 40 degrees in mid winter and the geothermal process will be subject to the inefficiencies described above.
- The heat exchange column in the Genung patent (U.S. Pat. No. 6,212,896) is set in a vertical bore hole to a maximum depth of 23 ft. The water filled column spans the depth between frost line and the region where the ground is at constant temperature. Therefore only the lower portion of the column is in position for optimum heat transfer. Genung terms his design a hybrid direct exchange. In fact, the heat flow is from ground/water/refrigerant. The heat exchange therefore is not a direct exchange between earth and copper refrigeration coils. The Genung column differs from other indirect systems primarily in the absence of a water circulating pump.
- Primary heat transfer at each of the Genung one ton rated columns is therefore between earth and the thermally circulated water. Heat transfer performance of slow moving water is poor. The recognized requirement of 6,000 cubic feet of earth to support one ton of heating or cooling establishes an envelope with a 9 foot radius about the 2 ft.×20 ft. column.
- In direct exchange deep bore design, a 6,000 cubic feet earth surround about a 100 ft. borehole results in an envelope with a 4.5 foot radius of heat drawn. Earth's poor diffusivity makes the 9 foot radius of heat draw about the Genung column problematic for good heat transfer. According to the patent supplemental exhaust is required during summer operation to reduce the heat buildup within the column. This is a further confirmation of compromised efficiency.
- A comparison of manufacturer's certified heat transfer data for the three principal types of geothermal systems confirms that heat pumps that are coupled to ground water systems operate with the highest COP (coefficient of performance). Since performance is tied to entry water temperature this is no surprise, however; what is noteworthy is that ground water systems performance exceeds that of direct exchange systems.
- Ground water usage is strictly regulated and the opportunities for open loop installations are limited.
- The pursuit of greater (energy saving) efficiencies drives the need for advancement in closed loop ground/water heat exchanger systems that are more efficient and less costly to install.
- There is a need for an appliance, which will approximate the performance of an underground stream. The need is for a heat exchange module so efficient that its output water temperature will approach that of an underground stream.
- The design of the exchanger must allow for maximum harvesting of ground heat with a minimum of operating pressure head losses. This translates to useable bore depths of 12-40 ft. where the temperature is relatively constant.
- To be cost effective the appliance must be modular, low cost, and suitable for factory assembly and mass production.
- Given the high cost of field labor the module must be easy to install, with basic equipment and relatively light in weight without need for special techniques.
- The present invention is able to address the need for a more efficient heat exchange module by introducing a cylindrical module utilizing concentric channels to effectively extract heat from the ground. The concentric channels within the cylindrical module utilizes the high thermal conductivity of saturated sand to effectively transfer heat from the ground to the water flowing through the module. When a plurality of the present invention's cylindrical modules are utilized in parallel, the harvesting of the ground heat is maximized. As a result, the water output temperature of the present invention is able to approach that of an underground stream.
- It is the nature of the Carnot cycle and therefore of heat pumps that larger temperature difference between source and sink results in lower efficiency. This is illustrated by the chart shown in
FIG. 5 , which shows diminishing thermal output corresponding to lower outdoor temperatures. - The conventional answer for dealing with diminished energy output is to supply supplemental energy through the use of electric resistance heaters. The heaters are usually mounted in the air supply ducts. The use of the supplementary electric heat dramatically raises the operating cost of geothermal systems.
- The present invention takes a more direct and cost efficient track to providing supplemental energy through a direct boost to the geothermal cycle. The new cycle establishes, by design, a minimum allowable entry water temperature (approx. 40° F.). Whenever the EWT drops below that level, supplemental energy is called upon to raise the level of water temperature. The result as shown in
FIG. 5 is a constant thermal output intersecting the heating load line and thermal output. The constant thermal output line is shown above the cross hatched area. The augmented EWT provides constant thermal output regardless of outside temperature. Since the heat pump remains the direct source of thermal output the transition from ordinary to augmented operation is seamless. - The point at which the heating load line and the thermal output line intersect is termed the design point. The present invention allows for thermal output above and beyond the design point. In addition to the benefit of increased thermal output, the system offers another advantage. In heating dominant climates, the size of the geothermal field may be reduced thereby saving on initial system costs.
- As is evident energy augmentation takes place at low temperatures. The process therefore lends itself to being supported by an ordinary domestic gas hot water heater or a combination of gas and solar heaters. Use of a dual purpose heater assures further economies in initial and operating costs.
- The present invention is a thermal exchange process to deliver water, in a closed loop ground/water system at temperatures approaching that of ground water. Such water temperatures were heretofore only achievable with ground water systems. Optimum energy saving and performance of ground coupled heat pumps are directly linked to heat exchange between a circulating water loop and ground temperature. The present invention allows for the optimization of energy and performance. Also provided by the present invention is an improved ground to water heat exchanger for geothermal heating and cooling. The ground to water heat exchanger is a sealed cylinder that is located substantially below the earth's surface surrounded by earth mass. Within the cylinder's thin outside wall is an annular column of saturated sand. During operation, circulating water from the user's heat pump flows from the top of the cylinder column through the saturated sand medium in a U-configuration at the desired pump rate. The slow passage of water, coaxial with the thin stainless steel cylinder wall together with the special conductivity characteristics of saturated sand assures efficient ground to water heat transfer. The improved heat transfer results in greater operating efficiencies for geothermal heating and cooling. In cooling dominant climates, the entry water is not manipulated with an augmented booster. The efficiency of heat pumps diminishes with descending outside air temperatures. This invention allows for the manipulation of entry water temperatures to stem the problem of diminishing efficiencies. However, the augmented booster system is optional and only serves to boost the heating performance of the heat pump. In the circumstance that the present invention is used in a colder climate and anti-freeze is not being used, the augmented booster is required to prevent the freezing of the water within the piping. The secondary benefit of the present invention is the potential reduction of the size of the geothermal field.
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FIG. 1 is a perspective sectional view of the geothermal exchange module in which a detailed view is taken and shown inFIG. 2 andFIG. 3 . -
FIG. 2 is a detailed view showing the top internal view of an assembled geothermal exchange module. -
FIG. 3 is a detailed view showing the bottom internal view of an assembled geothermal exchange module. -
FIG. 4 is a flow diagram of the temperature augmentation process, showing the refrigerant loop, the ground circuit, and the augmentation circuit. -
FIG. 5 is a graph showing the relationship of the thermal output with respect to outdoor temperature. - All illustrations of the drawings are for the purpose of describing selected versions of the present invention and are not intended to limit the scope of the present invention.
- It has been established that geothermal systems are most efficient when ground coupled heat transfer takes place at depths of 12 to 40 ft. or more and when exit water temperature most closely approximates ground temperature. The present invention provides such a geothermal heat exchange system and method. In reference to
FIG. 3 , the present invention is a geothermal exchange system making use of a ground circuit 1, anaugmentation circuit 2, arefrigerant loop 3, a refrigerant/water heat exchanger 4, and a augmentation water/water heat exchanger 5. The ground circuit 1 consists of a series of water loops of the geothermal exchange system that extend down into ground. This allows flowing water to extract or dispel heat in a geothermal heat exchange. Theaugmentation circuit 2 consists of dual loops for the present invention that provide augmentation of entry water temperature to improve the efficiency of the heat pump. Therefrigerant loop 3 is located within the user's heat pump. In reference toFIG. 3 , the ground circuit 1 comprises ageothermal exchange loop 11, antemperature augmentation loop 12, and aflow divider 131. Theaugmentation circuit 2 comprises a high temperaturelow volume loop 21, a low temperaturehigh volume loop 22, and a mixingvalve 24. Therefrigerant loop 3 is linked with thegeothermal exchange loop 11 of the ground circuit 1 by means of the refrigerant/water heat exchanger 4 located within the user's heat pump. The refrigerant towater heat exchanger 4 is supported by the ground circuit 1. Theaugmentation loop 12 of the ground circuit 1 is linked with the low temperaturehigh volume loop 22 of theaugmentation circuit 2 by means of the water towater heat exchanger 5. The water temperature through the ground circuit 1 is augmented through the water towater heat exchanger 5 which they have in common. - The main goal of the ground circuit 1 is to extract heat from the
earth 12 to 40 feet or more deep. Thegeothermal exchange loop 11 is connected to the temperatureaugmentation exchange loop 12 by the sharedpipe branch 13. Thegeothermal loop 11 comprises a plurality ofgeothermal exchange modules 111. Thegeothermal exchange loop 11 is the portion of the ground circuit 1 that extracts heat from the earth through a series of the plurality ofgeothermal exchange modules 111. In reference toFIG. 2 , each of thegeothermal exchange modules 111 comprises a thin wallouter shell 112, aninner pipe 113, anouter passageway 116, aninner passageway 117, aend plate 118, an o-ring seal 120, and anoptional tie rod 121. Thegeothermal exchange modules 111 are a uniquely designed thermal exchange modules with enhanced heat transfer properties. The thin wallouter shell 112 of the geothermal exchange module is a cylindrically shaped component. The thin wallouter shell 112 possesses a sealed base. In the preferred embodiment of the present invention, the thin wallouter shell 112 is made from stainless steel with a hemispherical base. However, in other embodiments of the present invention, other suitable materials with high heat transfer properties can be used for the thin wallouter shell 112. The material must allow for maximum heat transfer yet remain chemically neutral to the environment. Theinner pipe 113 is similarly cylindrically shaped, but with a smaller diameter and slightly shorter length. In the preferred embodiment of the present invention, theinner pipe 113 is made from a plastic material. Theinner pipe 113 is positioned within the thin wallouter shell 112 in a concentric relationship. The positioning of theinner pipe 113 inside the thin wallouter shell 112 defines theouter passageway 116 and theinner passageway 117. The outer passage way is the space defined between the walls of the thin wallouter shell 112 and theinner pipe 113. Theinner passageway 117 is defined by the space traversing through theinner pipe 113. The inner passage way and theouter passageway 116 are sealed by means of theend plate 118. Theend plate 118 is engaged to the top end of the thin wallouter shell 112 and theinner pipe 113 to seal theinner passageway 117 and theouter passageway 116. Theouter passageway 116 is isolated from theinner passageway 117. Theouter passageway 116 is filled with aconductive element 122. Theconductive element 122 is a particle filled into theouter passageway 116 that still allows water to flow through. In the preferred embodiment of the present invention theconductive element 122 is saturatedsand 122. In reference toFIG. 2 , theinner pipe 113 further comprises of a plurality ofopenings 114. The plurality ofopenings 114 is circumferentially positioned about a lower end of theinner pipe 113. The plurality ofopenings 114 connects theouter passageway 116 with theinner passageway 117. Water flowing through theinner passageway 117 will go through the plurality ofopenings 114 to access theouter passageway 116. Optionally, to hold theend plate 118 to the thin wallouter shell 112 and theinner pipe 113, theoptional tie rod 121 is traversed through theinner passageway 117 and secures theend plate 118 to the base of the thin wallouter shell 112. To ensure theend plate 118 is hermetically sealed to the thin wallouter shell 112, the end plate further comprises of aseal groove 119. Theseal groove 119 is a recessed groove positioned peripherally about the end plate. The o-ring seal 120 is positioned in between theseal groove 119 and the thin wallouter shell 112 to fully seal theinner passageway 117 and theouter passageway 116. The plurality ofgeothermal exchange modules 111 are connected in parallel relationship allowing water to flow into each of theinner passageways 117 for each module. The water flows out of theouter passageways 116 for each module to converge and continue through thegeothermal exchange loop 11. Theaugmentation exchange loop 12 is a parallel branch connected to thegeothermal exchange loop 11 by means of the sharedpipe branch 13. The flow divider is positioned on a node between theaugmentation loop 12 and thegeothermal exchange loop 11. Theflow divider 131 follows the plurality ofgeothermal exchange modules 111. Theflow divider 131 is positioned in the user's home and is connected to and distributes water from the plurality ofgeothermal exchange modules 111 to the water/water heat exchanger 5 and the refrigerant/water heat exchanger 4. The augmentation water/water heat exchanger 5 is connected in-line with theaugmentation exchange loop 12 and is connected directly to theflow divider 131. Theflow divider 131 directs water flow from the plurality ofgeothermal exchange modules 111 into both the sharedpipe branch 13 and theaugmentation exchange loop 12. The water flow through the sharedpipe branch 13 and returns directly to the refrigerant/water heat exchanger 4. The water flowing through theaugmentation loop 12 passes through the water/water heat exchanger 5 for temperature augmentation and returns to the refrigerant/water heat pump 4. - In reference to
FIG. 4 , the high temperaturelow volume loop 21 comprises awater heater 211. The low temperaturehigh volume loop 22 comprises of apump 221. The high temperaturelow volume loop 21 is connected to the low temperaturehigh volume loop 22 by means of awater recirculation branch 23. The mixingvalve 24 is positioned on a high to low temperature node. Thepump 221 is connected in line with the low temperaturehigh volume loop 22. Thewater heater 211 is connected in line with the mixingvalve 24 and the high temperaturelow volume loop 21. - Provided the
refrigerant loop 3, the ground circuit 1, and theaugmentation circuit 2 with water flowing through, the present invention is able to provide an efficient thermal exchange system. - In circumstances wherein the entry water temperature is less than 40° F., antifreeze will be used with water to prevent any freezing and blockage in the ground circuit 1. The use of the augmentation circuit provides for higher performance and prevents the freezing of water within the system. However, with the use of antifreeze, the use of an augmentation circuit is optional. With water flowing through the ground circuit 1 and the
augmentation circuit 2, water temperature is boosted as it enters the refrigerant/water heat exchanger 4. Energy is provided and transferred to the ground circuit 1 from theaugmentation circuit 2 by means of the water/water heat exchanger 5. With heat extracted from the water at the refrigerant/water heat exchanger 4, the water returns to the plurality ofgeothermal exchange modules 111 to extract heat from the ground. The water flows into each of thegeothermal exchange modules 111 through theinner passageways 117 and through theouter passageway 116 through the plurality ofopenings 114. While flowing through theouter passageway 116, the water is able to extract heat directly from the saturatedsand 122. To minimize pressure drop, all piping between cylinders is run in parallel. The piping between bores is also arranged in parallel relationship. As a conductor of heat, water is a relatively poor performer.Saturated sand 122, however, has five times the conductivity of water. This greatly improves the heat transfer between the sand/water mixture and the surrounding earth mass and in turn between the saturatedsand 122 and the flowing water. The area of theouter passageway 116 and the cylinder length are coordinated to maximize heat transfer and water residence time. In another embodiment of the present invention, the water can flow into each of thegeothermal exchange modules 111 through theouter passageways 116 and out from theinner passageways 117. The water exits theouter passageway 116 and flows towards theflow divider 131. Theflow divider 131 splits the flow of the water into theaugmentation loop 12 and the sharedbranch 13. The flow through the shared branch returns to the refrigerant/water heat exchanger 4. The flow through theaugmentation loop 12 extracts heat from theaugmentation circuit 2 through the augmentation water/water heat exchanger 5 and continues to the refrigerant/water heat exchanger 4. The water from the sharedpipe branch 13 and theaugmentation loop 12 mixes with additional heat energy to be transferred to therefrigerant loop 3. The cycle of the water flow repeats to continually provide heat to therefrigerant loop 3. - As a low pressure system there is very little work energy consumed by the circulating water pump. Indeed the
pump 221 circulator consumes less than 50 watts per ton. This is less energy than that which is consumed by a well pump or any indirect exchange system. - For the arrangement of the
geothermal exchange modules 111, there may be one or more module stacked in line in each bore hole. When more than one module is used in a given bored hole, the modules are separated by a spacer. The spacer allows each module to maximize its harvest of heat. This has the result of minimizing the actual cylinder length while increasing the effective length per bore. - The
augmentation circuit 2 is a closed circuit system that is able to add heat energy to the ground circuit 1 through the high temperaturelow volume loop 21 and the low temperaturehigh volume loop 22. With water flowing through the augmentation circuit, thewater heater 211 provides supplementary heat to the water by means of a domestic hot water heater. In other embodiments of the present invention, thewater heater 211 can provide supplementary energy through gas or solar heat. Heated water flows from the water heater towards the mixingvalve 24. The heated water flows into mixingvalve 24 and enters the low temperaturehigh volume loop 22. The heated water is then facilitated through the low temperaturehigh volume loops 22 by thepump 221 through the augmentation water/water heat exchanger 5 and the low temperaturehigh volume loop 22. In the water/water heat exchanger 5 the heat in the water is transferred to the water flowing through the ground circuit 1. Upon exiting the augmentation water/water heat exchanger 5, the water flow is split towards the mixingvalve 24 and thewater heater 211. The portion of the water flows back into thewater recirculation branch 23 back into the mixingvalve 24. The recycled water is mixed with newly heated water from thewater heater 211 to be pumped through the low temperaturehigh volume loop 22 again. - Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
Claims (17)
1. The geothermal exchange module and augmented thermal exchange system comprises,
a ground circuit;
an augmentation circuit;
a refrigerant loop;
a refrigerant/water heat pump;
an augmentation water/water heat exchanger;
a plurality of geothermal exchange module;
the ground circuit being linked with the refrigerant loop by means of the refrigerant/water heat pump;
the augmentation circuit being linked with the ground circuit by means of the augmentation water/water heat exchanger; and
each geothermal exchange module comprises of a thin wall outer shell, an inner pipe, an outer passageway, an inner passageways, a end plate, an o-ring seal, and optional tie rod.
2. The geothermal exchange module and augmented thermal exchange system as claimed in claim 1 comprises,
the thin wall outer shell being cylindrically shaped;
the inner pipe being cylindrically shaped; and
the inner pipe being positioned within the thin wall outer shell in concentric relationship.
3. The geothermal exchange module and augmented thermal exchange system as claimed in claim 2 comprises,
the inner pipe comprises of a plurality of openings;
the outer passageway being a space defined by the thin wall outer shell and the inner pipe; and
the inner passageway being a space traversing through the inner pipe.
4. The geothermal exchange module and augmented thermal exchange system as claimed in claim 3 comprises,
the end plate being engaged to a top end of the thin wall outer shell sealing the outer passageway and sealing the inner passageway, wherein the outer passageway and the inner passageway are isolated; and
the outer passageway being filled with a conductive element, wherein the conductive element is sand.
5. The geothermal exchange module and augmented thermal exchange system as claimed in claim 3 comprises,
the plurality of openings being positioned on a lower end of the inner pipe, wherein the plurality of openings connects the outer passageway with the inner passageway; and
the optional tie rod being traversed through the inner passageway and being secured to the end plate and the thin wall outer shell.
6. The geothermal exchange module and augmented thermal exchange system as claimed in claim 3 comprises,
the end plate having a seal groove; and
the o-ring seal being positioned in between the seal groove and the thin wall outer shell to fully seal the inner passageway and the outer passageway.
7. The augmented thermal exchange system using a geothermal exchange module as claimed in claim 3 comprises,
the plurality of geothermal exchange modules being connected in parallel relationship on the ground circuit; and
the ground circuit and the augmentation circuit being a closed system.
8. A method of using a geothermal exchange module in an augmented thermal exchange system comprises,
providing a refrigerant loop, a ground circuit, and a augmentation circuit;
flowing of water through the refrigerant loop, the ground circuit, and the augmentation circuit;
transferring of heat from the ground circuit to the refrigerant loop by means of a refrigerant/water heat pump; and
transferring of augmented heat from the augmentation circuit to the ground circuit by means of the augmentation water/water heat exchanger.
9. The method of using a geothermal exchange module in an augmented thermal exchange system as claimed in claim 8 comprises,
cycling of the water flow in the ground circuit from the refrigerant/water heat pump to a plurality of geothermal exchange modules;
wherein the geothermal exchange modules are buried in bore holes underground;
extracting of ground heat from the ground by the geothermal exchange modules; and
absorbing of ground heat by the water flowing through the geothermal exchange modules.
10. The method of using a geothermal exchange module in an augmented thermal exchange system as claimed in claim 8 comprises,
extracting the augmented heat from the augmentation circuit by the augmentation water/water heat exchanger; and
absorbing the augmented heat by the ground circuit through the augmentation water/water heat exchanger.
11. The method of using a geothermal exchange module in an augmented thermal exchange system as claimed in claim 9 comprises,
wherein the flowing of the water within the ground circuit branches off into each of the plurality of geothermal exchange modules entering each of the geothermal exchange modules through an inner passageway, through a plurality of openings into an outer passageway, through a conductive element, and out back into the geothermal exchange loop.
12. The method of using a geothermal exchange module in an augmented thermal exchange system as claimed in claim 10 comprises,
wherein the augmentation circuit having a water heater in circuit is able to provide augmented heat for the ground circuit through the augmentation water/water heat exchanger; and
wherein the augmented heat is provided for the water flowing in the ground circuit on top of the heat extracted from the ground through the plurality of ground exchange modules.
13. The geothermal exchange module and augmented thermal exchange system comprises,
a ground circuit;
an augmentation circuit;
a refrigerant loop;
a refrigerant/water heat pump;
an augmentation water/water heat exchanger;
a plurality of geothermal exchange module;
the ground circuit being linked with the refrigerant loop by means of the refrigerant/water heat pump;
the augmentation circuit being linked with the ground circuit by means of the augmentation water/water heat exchanger;
each geothermal exchange module comprises of a thin wall outer shell, an inner pipe, an outer passageway, an inner passageways, a end plate, an o-ring seal, and optional tie rod;
the thin wall outer shell being cylindrically shaped;
the inner pipe being cylindrically shaped;
the inner pipe being positioned within the thin wall outer shell in concentric relationship;
the inner pipe comprises of a plurality of openings;
the outer passageway being a space defined by the thin wall outer shell and the inner pipe; and
the inner passageway being a space traversing through the inner pipe.
14. The geothermal exchange module and augmented thermal exchange system as claimed in claim 13 comprises,
the end plate being engaged to a top end of the thin wall outer shell sealing the outer passageway and sealing the inner passageway, wherein the outer passageway and the inner passageway are isolated; and
the outer passageway being filled with a conductive element, wherein the conductive element is sand.
15. The geothermal exchange module and augmented thermal exchange system as claimed in claim 13 comprises,
the plurality of openings being positioned on a lower end of the inner pipe, wherein the plurality of openings connects the outer passageway with the inner passageway; and
the optional tie rod being traversed through the inner passageway and being secured to the end plate and the thin wall outer shell.
16. The geothermal exchange module and augmented thermal exchange system as claimed in claim 13 comprises,
the end plate having a seal groove; and
the o-ring seal being positioned in between the seal groove and the thin wall outer shell to fully seal the inner passageway and the outer passageway.
17. The geothermal exchange module and augmented thermal exchange system as claimed in claim 13 comprises,
the plurality of geothermal exchange modules being connected in parallel relationship on the ground circuit; and
the ground circuit and the augmentation circuit being a closed system.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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US13/155,252 US20110308268A1 (en) | 2010-06-17 | 2011-06-07 | Geothermal Exchange Module and a Method of use with an Augmented Water Temperature System |
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Application Number | Priority Date | Filing Date | Title |
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US35573410P | 2010-06-17 | 2010-06-17 | |
US13/155,252 US20110308268A1 (en) | 2010-06-17 | 2011-06-07 | Geothermal Exchange Module and a Method of use with an Augmented Water Temperature System |
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US13/155,252 Abandoned US20110308268A1 (en) | 2010-06-17 | 2011-06-07 | Geothermal Exchange Module and a Method of use with an Augmented Water Temperature System |
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US20100270003A1 (en) * | 2009-04-27 | 2010-10-28 | Alberto Sarria | Two-concentric pipe system to heat fluids using the earth's interior thermal energy (deep) |
US20130037236A1 (en) * | 2010-04-20 | 2013-02-14 | Bsr Technologies | Geothermal facility with thermal recharging of the subsoil |
WO2013185083A3 (en) * | 2012-06-07 | 2014-06-26 | Braun Intertec Geothermal, Llc | Ground heat exchange processes and equipment |
US9593868B2 (en) | 2015-02-20 | 2017-03-14 | Vladimir Entin | Horizontal ground-coupled heat exchanger for geothermal systems |
US9702574B2 (en) | 2013-05-09 | 2017-07-11 | Steven B. Haupt | Ground water air conditioning systems and associated methods |
US9915436B1 (en) | 2015-01-20 | 2018-03-13 | Ralph Feria | Heat source optimization system |
US11067317B2 (en) | 2015-01-20 | 2021-07-20 | Ralph Feria | Heat source optimization system |
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Publication number | Priority date | Publication date | Assignee | Title |
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US20100270003A1 (en) * | 2009-04-27 | 2010-10-28 | Alberto Sarria | Two-concentric pipe system to heat fluids using the earth's interior thermal energy (deep) |
US8307896B2 (en) * | 2009-04-27 | 2012-11-13 | Alberto Sarria | Two-concentric pipe system to heat fluids using the earth's interior thermal energy (deep) |
US20130037236A1 (en) * | 2010-04-20 | 2013-02-14 | Bsr Technologies | Geothermal facility with thermal recharging of the subsoil |
WO2013185083A3 (en) * | 2012-06-07 | 2014-06-26 | Braun Intertec Geothermal, Llc | Ground heat exchange processes and equipment |
US9157666B2 (en) | 2012-06-07 | 2015-10-13 | Braun Intertec Geothermal, Llc | Ground heat exchange processes and equipment |
US9702574B2 (en) | 2013-05-09 | 2017-07-11 | Steven B. Haupt | Ground water air conditioning systems and associated methods |
US9915436B1 (en) | 2015-01-20 | 2018-03-13 | Ralph Feria | Heat source optimization system |
US11067317B2 (en) | 2015-01-20 | 2021-07-20 | Ralph Feria | Heat source optimization system |
US9593868B2 (en) | 2015-02-20 | 2017-03-14 | Vladimir Entin | Horizontal ground-coupled heat exchanger for geothermal systems |
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