DIRECT EXCHANGE HEAT PUMP WITH GROUND PROBE OF IRON ANGLED AT 25 DEGREES OR LESS OR OTHER MATERIAL ANGLED AT 4 DEGREES OR LESS TO THE HORIZONTAL

Abstract

Disclosed is a ground probe heat pump system including a direct exchange heat exchanger installed in the earth at a nearly horizontal angle. The ground probe includes separate flow paths for a working fluid allowing the working fluid to directly exchange heat energy with the ground. Also disclosed are methods of installing multiple probes and heat pump systems in various arrangements separately or in conjunction with existing heating and cooling systems. Included are embodiments of the ground probe which are predominantly iron configured to be inserted through a below-ground level structure such as a basement wall by pounding or otherwise applying pressure to the ground probe.

Description

BACKGROUND

Heat pumps are common in homes and commercial settings for both heating and cooling the air inside a building. Heat pump systems commonly use a working fluid to move thermal energy along a closed loop by compressing the working fluid in a gas phase thus raising its temperature and pressure. Excess heat is dissipated condensing the high pressure working fluid into a somewhat cooler liquid phase. The working fluid is then allowed to reduce pressure creating a two-phase liquid and gas working fluid that absorbs energy as it evaporates back into a cooler, lower pressure, gas. The working fluid is then compressed again and the cycle is repeated.

In many instances, the heat dissipated in condensing the working fluid to a liquid, and the heat absorbed in evaporating the working fluid to a gas, are obtained from the air using fans or and air heat exchangers either inside or outside the building. Heating or cooling can be achieved by selectively controlling the movement of the working fluid through a series of valves between the heat exchangers. In hot weather, an outdoor heat exchanger dissipates the heat of condensation into the air while an indoor heat exchanger cools the indoor air absorbing heat as the working fluid evaporates. By reversing the flow and sequence, heating inside the building is achieved using the indoor exchanger as a condenser, and the outdoor exchanger as an evaporator.

However, as the difference between the air temperature and the working fluid temperature narrows, it becomes more and more difficult to transfer thermal energy. This becomes especially difficult in the winter months where the thermal load on the structure is high and the ambient air temperature is very low, perhaps even below 0 degrees Fahrenheit. As outdoor temperatures drop below about 35 to 40 degrees Fahrenheit, air source heat pumps become increasingly less efficient at moving heat. If the air is cold enough, and the thermal load high enough, an air source heat pump will not be able to move heat energy into the structure fast enough to replace heat lost to convection, conduction, and radiation.

Ground source or geothermal heat pumps provide one solution to the difficulties caused by the seasonal swings in the ambient air temperature. Temperatures below ground near the earth's surface (such as within 50 feet) are generally between 50 and 60 degrees in most places, even in northern latitudes. Geothermal systems can be fairly effective at using the earth as a heat source for collecting heat energy in winter, or as a heat sink for absorbing excess heat in summer. Although ground temperatures fluctuate somewhat with the seasons, the change is small when compared to the perhaps 50 to 100 degree Fahrenheit seasonal swings in ambient air temperature many air source heat pumps may try to accommodate.

To create the necessary heat exchange, some geothermal systems circulate a liquid solution such as a water and ethylene glycol mixture through plastic tubes buried in a continuous loop underground. In a horizontal installation, the loop is buried horizontally around 6 to 10 feet underground, while in a vertical installation, the loop is buried in one or more bore holes which may be 100 feet deep or more. A heat exchanger transfers heat between the liquid passing through the buried loop transferring heat between the circulating liquid in the loop and the working fluid in the heating and cooling system. Heat energy is exchanged between the liquid in the loop and the ground, and then exchanged again between the liquid and the working fluid.

Although relatively effective, such systems require extra energy to operate because of the extra heat exchange process between the liquid circulating through the ground loop and the working fluid circulating through the heating and air-conditioning system in the building. Because of this extra heat exchange process, the temperature differential between one end of the loop and the other is generally only a few degrees thus requiring the ground loop to be hundreds of feet long in order to achieve sufficient timely thermal transfer with the earth to achieve positive results. Ground loops are therefore typically installed with plastic pipe to reduce cost even though the rate of thermal transfer between the fluid and the ground is reduced because of the insulative nature of plastic, an aspect of the design that requires the loop to be even longer. Because the loop is so long, heavy trenching or drilling equipment is generally required to install the loops, either vertically, or horizontally. This installation cost is often the largest portion of installing a geothermal system, particularly in a residential setting. Also, because many homes in residential settings are located on small lots, the only installation available is a vertical installation which can be the most expensive of all requiring multiple deep bore holes to be drilled thus making the investment in a ground source heat pump prohibitively expensive.

Some advantages can be obtained by circulating the working fluid in the ground loop in metal tubing instead of a secondary fluid in plastic tubing. These systems, often referred to as “direct exchange” systems, increase efficiency by eliminating the heat transfer between the water and the working fluid. By circulating the working fluid itself, the direct thermal exchange between the working fluid and the earth occurs more quickly thus increasing efficiency. However, installing direct exchange ground loops usually requires drilling bore holes for the loop, and then filling the airspace around the tubing with a grout or other suitable filler to reduce the opportunity for inefficiencies created by air pockets in the bore holes. Thus the installation of the direct exchange loop can also be complex and prohibitively expensive.

SUMMARY

Disclosed is a direct exchange ground probe heat pump system that includes a probe inserted into the ground at an angle that is nearly horizontal. The probe operates as a ground source heat exchanger with counter-current flow paths for a working fluid. A first path and a separate second path are defined within the probe and are coupled to one another near a closed end of the probe. The probe is positioned with the closed end in the earth and the opposite working end projecting out of the earth. The working end is coupled to a compressor and another heat exchanger, such as an air heat exchanger, positioned in a building thus creating a closed loop containing the working fluid. In operation, the working fluid transfers heat through the walls of the probe to and from the earth around the probe. The opposite heat transfer can be initiated by the other heat exchanger using the compressor to heat and cool a building. The ground probe operates as a condenser when the heat pump is operating in the cooling mode, and as an evaporator when it is operating in a heating mode.

Various embodiments of the ground probe are also disclosed. In one example, an second outer tube constructed predominantly of iron or a predominantly iron alloy such as steel defines the second separate path while a first inner tube positioned within the second outer tube defines the first path. The first inner tube may optionally be constructed with or covered with, a layer of a less thermally conductive material such as Nylon or PVC. In another embodiment, the ground probe includes a metering device in the first path configured for the heating mode.

Also disclosed are methods for installing a predominantly iron probe at a nearly horizontal angle such as 25 degrees or less from horizontal. A predominantly iron probe is inserted through the below ground wall of the structure such as a footing, basement wall, and the like. This insertion can be made by first creating a hole through the structure, and then inserting the second closed end of the ground probe into the earth outside the wall by applying pressure to the first working end such as by repeatedly pounding, or tapping the first working end of the probe. The ground probe is thus forced into the earth minimizing the opportunity for air pockets to form around the probe without the use of any drilling equipment or filler. Upon insertion, the ground probe is then coupled to a compressor and another heat exchanger to provide heating or cooling. In one embodiment, the heat pump system is coupled to an existing heating and cooling system while in another, it is installed as a separate heating and cooling system.

In another aspect, multiple heat pump systems are disclosed coupled to various heating and cooling systems within a building. Various installations are described including a below ground installation in a below ground room such as a basement where the heat pump and the heating and cooling system are in the same room. Also disclosed is a below ground installation into a space such as a crawl space where the heat pump and the heating and cooling system are in separate rooms.

Further forms, objects, features, aspects, benefits, advantages, and embodiments of the present invention will become apparent from the detailed description and drawings provided herewith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a nearly horizontal ground probe heat pump system.

FIG. 2A is a first cross sectional view of a first embodiment of a ground probe for use with the heat pump system of FIG. 1.

FIG. 2B is a second cross sectional view of the embodiment of the ground probe shown in FIG. 2A.

FIG. 2C is a cross sectional view of a second embodiment of a ground probe for use with the heat pump system of FIG. 1.

FIG. 3A is a schematic diagram of a first building with the ground probe heat pump system of FIG. 1 installed.

FIG. 3B is a schematic diagram of a second building with the ground probe heat pump system of FIG. 1 installed.

FIG. 4A is a schematic diagram illustrating an installation of multiple ground probe heat pump systems of FIG. 1.

FIG. 4B is a schematic diagram illustrating an alternate installation of certain aspects of the ground probe heat pump systems shown in FIG. 4A.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates. One embodiment of the invention is shown in great detail, although it will be apparent to those skilled in the relevant art that some features not relevant to the present invention may not be shown for the sake of clarity.

The reference numerals in the following description have been organized to aid the reader in quickly identifying the drawings where various components are first shown. In particular, the drawing in which an element first appears is typically indicated by the left-most digit(s) in the corresponding reference number. For example, an element identified by a “100” series reference numeral will first appear in FIG. 1, an element identified by a “200” series reference numeral will first appear in FIG. 2, and so on. With reference to the Specification, Abstract, and Claims sections herein, it should be noted that the singular forms “a”, “an”, “the”, and the like include plural referents unless expressly discussed otherwise. As an illustration, references to “a device” or “the device” include one or more of such devices and equivalents thereof. It should also be noted that elements in the drawings are represented schematically unless otherwise indicated. Therefore absolute and relative sizes, angles, positioning, and the like, of elements in the figures may be exaggerated to better illustrate various aspects of the disclosure.

One embodiment of a nearly horizontal ground probe heat pump system is illustrated in FIG. 1 at 100. A first heat exchanger 110 is coupled to a second heat exchanger 120 in a closed also including a compressor 130. Compressor 130, first heat exchanger 110, and second heat exchanger 120 operate together in either a heating or cooling capacity circulating a working fluid in a closed loop as described in further detail below.

First heat exchanger 110 is illustrated as vertically mounted on a lower surface 108 of a duct 115 so that an air flow 114 may pass through it. Heat is either rejected into air flow 114 from first heat exchanger 110 raising its temperature, or heat is absorbed from air flow 114 by first heat exchanger 110 thus reducing its temperature. In order to achieve this heat transfer, first heat exchanger 110 is coupled to a first line 116 for carrying the working fluid, first line 116 is coupled to first exchanger 110 at a upper connection 113. A second line 117 is also coupled to heat exchanger 110 at a lower connection 112. A first metering device 111 is positioned between lower connection 112 and second line 117 and includes a bypass. Metering device 111 is preferably a variable metering device, such as a conventional expansion valve and the like. In one embodiment, first metering device 111 allows working fluid passing into first heat exchanger 110 through second line 117 to reduce pressure expanding into a two-phase liquid and vapor combination. On the other hand, working fluid passing out of heat exchanger 110 through first metering device 111 into second line 117 can bypass the change in pressure and maintain its pressure as it moves toward second heat exchanger 120.

Second line 117 is also coupled to a second metering device 126 which may also include a bypass feature. Second metering device 126 may be similar to first metering device 111 in that it is preferably a variable metering device, such as a conventional expansion valve and the like. The second metering device 126 is coupled to second heat exchanger 120 by a working end coupling 122 at or near first working end 121. Second metering device 126 may be configured to operate like metering device 111 in that may also be capable of allowing working fluid passing into second heat exchanger 120 through second line 117 to reduce in pressure allowing the formation of a two-phase liquid and gas combination. In this configuration, second metering device 126 may also includes a bypass that allows working fluid passing out of second heat exchanger 120 into second line 117 to maintain it's pressure as it moves toward first heat exchanger 110 along the closed loop.

As will be shown in FIG. 2C, some embodiments of the second heat exchanger 120 may include a metering device such as a fixed or variable expansion device within ground probe 124 rather than mounting the device to first working end 121. In that case, second line 117 is coupled directly to working end coupling 122 and no second metering device 126 is coupled outside probe 124 at first working end 121.

Second heat exchanger 120 includes a ground probe 124, examples of which are illustrated in further detail in FIGS. 2A through 2C and described below. Ground probe 124 is positioned with a first working end 121 and a second closed end 125, the enclosed end 125 positioned in the earth 142. Ground probe 124 is coupled to first heat exchanger 110 near a first working end 121 where second line 117 couples to first working end 121 using a working end coupling 122.

As shown in greater detail in FIGS. 2A and 2B, ground probe 124 defines a first path and a separate second path. The two paths are coupled to one another inside ground probe 124 near second closed and 125. Working fluid circulating through the two paths absorbs heat directly from the earth 142 around ground probe 124 in the heating mode, or rejects heat directly from the working fluid into the earth 142 in the cooling mode. The first path exits ground probe 124 at first working end 121 through working end coupling 122. The separate second path exits ground probe 124 at a second reversing valve coupling 123 which couples the second path to a reversing valve 132 through a second compressor line 134.

Reversing valve 132 is coupled to a compressor 130 which includes a compressor body 136, a compressor suction inlet 131 and a compressor outlet 133. Compressor suction inlet 131, and compressor output 133 are coupled to reversing valve 132. The reversing valve is also coupled to second reversing valve coupling 123 through second compressor line 134. Second compressor line 134 allows working fluid from the separate second path to enter and exit ground probe 124 from reversing valve 132. First line 116 is also coupled to reversing valve 132 as well at first reversing valve coupling 135 thus allowing working fluid to enter first heat exchanger 110 from compressor 130 through reversing valve 132.

In the illustrated embodiment, compressor 130 and ground probe 124 are mounted on a mounting bracket 140 which is secured to a wall 141. Mounting bracket 140 includes a guide 143 which aid in positioning ground probe 124 at the proper angle as it is inserted through wall 141. Mounting bracket 140 is positioned on an inside surface 144 of wall 141 and configured so that ground probe 124 passes through bracket 140 and wall 141 into the earth 142 which is adjacent an outside surface 145 of wall 141.

Also illustrated in FIG. 1 is a controller 150 which may also be included with ground probe heat pump system 100. Controller 150 may be coupled to compressor 130 using a control line 151. Controller 150 may include various types of controls such as an electronic or mechanical thermostat, a mechanical switch, or plugging in the power cord to name a few. In the illustrated embodiment, controller 150 includes a thermostat for activating ground probe heat pump system 100 when temperatures in the building reach preprogram setpoints. Further detail on these and other aspects are discussed below with respect to FIGS. 3A and 3B.

In operation in the heating mode, reversing valve 132 is configured to couple compressor suction inlet 131 to second compressor line 134, and compressor outlet 133 to first line 116. In this configuration, as compressor 130 operates, it compresses working fluid vapors pulled from the second path within ground probe 124 into a relatively high pressure superheated vapor passing through first line 116 into first heat exchanger 110. As air flow 114 passes through first heat exchanger 110, heat from the high pressure vapor within first heat exchanger 110 is rejected into air flow 114, and passes through duct 115. As the vapors cool, they condense into a warm, still relatively high pressure liquid. The vertical mounting of heat exchanger 110 allows gravity to aid in the collection of the condensed liquid working fluid from the lower portion of first heat exchanger 110. However, other embodiments of heat exchanger 110 may be configured with different mountings as well. In any case, second line 117 carries the warm condensed liquid at relatively high pressure through first metering device 111 utilizing the bypass to avoid any change in pressure until reaching second metering device 126. Upon passing through metering device 126 into ground probe 124, the working fluid pressure is allowed to decrease substantially causing the warm high-pressure condensed liquid and second line 117 to expand, reduce pressure, and cool thus separating into a two-phase liquid and gas combination as it passes into the first path within ground probe 124.

As described in further detail in FIG. 2, the warm high-pressure working fluid passes through the first path in ground probe 124 and as it transitions to the second path, it absorbs heat from the earth 142 to evaporate the liquid phase of the two-phase working fluid. As the liquid phase evaporates to vapor, the vapors are again reintroduced into compressor suction inlet 131 through second reversing valve coupling 123 and second compressor line 134 and the process is repeated. In this way, heat is collected by the working fluid within ground probe 124 and transferred to first heat exchanger 110 where it is rejected into air flow 114. The working fluid is then recirculated repeatedly to continuously transfer heat from the earth 142 to air flow 114 as long as heat pump system 100 is active.

In the cooling mode, reversing valve 132 is configured to couple compressor suction inlet 131 to first line 116 and compressor output 133 to second compressor line 134 thus effectively reversing the flow of the working fluid with respect to the heating mode. Compressor 130 compresses the working fluid vapors drawn from first heat exchanger 110 through first line 116. The compressed vapors are introduced into the second path within ground probe 124 as a superheated vapor under high-pressure. Here ground probe 124 operates as a condenser and the superheated vapor rejects heat into the earth 142 around ground probe 124. As heat is rejected, the working fluid becomes a warm liquid under high-pressure which is then passed along the first path through second line 117. As the warm condensed liquid passes through second metering device 126, the expansion process is bypassed allowing the liquid to maintain its relatively high pressure and temperature.

Upon arriving at first metering device 111, the warm high-pressure liquid is allowed to expand within first heat exchanger 110 thus creating the two-phase liquid and vapor combination within first heat exchanger 110 at a reduced temperature and pressure. Heat from air flow 114 passing through first heat exchanger 110 is absorbed as first heat exchanger 110 operates as an evaporator evaporating the liquid phase into vapors which are then reintroduced into compressor suction inlet 131 through first line 116 and reversing valve 132. Thus in this configuration, second heat exchanger operates as a condenser while first heat exchanger operates as an evaporator cooling air flow 114 by moving heat from air flow 114 into the earth 142 around ground probe 124.

Examples of working fluids which may be used include chlorodifluoromethane (CHC1F2) commonly referred to by the American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE) as R-22, mixtures of Butane (C4H10) and Propane (C3H8) often referred to as R-22A, or mixtures of difluoromethane (CH2F2) and pentafluoroethane (CHF2CF3) commonly referred to by the ASHRAE designation R-410A, as well as tetrafluoroethane (CH2FCF3) commonly referred to by the ASHRAE designation R-134A. Other suitable working fluids may also be used taking into consideration the pressures and temperatures at which the working fluid changes phase from a liquid to a gas along with the rated working pressures of the first heat exchanger 110, second heat exchanger 120, compressor 130, and the lines and fittings coupling these components together in a closed loop as described above.

Further detail of second heat exchanger 120 is provided in FIGS. 2A, 2B, and 2C illustrating two different embodiments while making reference to parts introduced in FIG. 1 as well. FIG. 2A is a cutaway cross section of one embodiment of heat exchanger 120 taken along a line DE shown in FIG. 2B. FIG. 2B is conversely a cutaway cross section of the same embodiment of heat exchanger 120 taken along line BC shown in FIG. 2A. FIG. 2C is cutaway cross-sectional view of a second embodiment of heat exchanger 120 which is similar to FIG. 2A configured preferably for the heating mode. In FIG. 2C, a metering device is positioned within the first flow path inside ground probe 124 rather than coupled to first working end 121 outside ground probe 124 as shown in FIG. 1.

In the embodiment illustrated in FIG. 2A, ground probe 124 has a second closed end 125 and a first working end 121. As discussed above, second heat exchanger 120 operates as part of a closed loop containing a working fluid 235. Working fluid 235 may at different times appear within second heat exchanger 120 as either a liquid, a gas, or a two-phase combination of liquid and gas depending on the pressure and temperature within second heat exchanger 120.

The illustrated embodiment of second heat exchanger 120 facilitates the exchange of heat discussed above between the ground outside ground probe 124 and working fluid 235 inside by providing countercurrent flow paths for working fluid 235. A first path 210 is defined by a first tube 217 positioned within a second tube 225. A separate second path 212 is defined by second tube 225 and first tube 217 (here shown with an optional insulative layer 219). Second tube 225 is coupled to second compressor line 134 near first working end 121. Second tube 225 may be spaced away from first tube 217 along a major length of second tube 225 by one or more standoffs 220. Standoffs 220 are configured to position first tube 217 away from second tube 225 while still allowing working fluid 235 to transfer from second closed end 125 to second compressor line 134 through second path 212.

Various embodiments of standoffs 220 are envisioned. For example, one embodiment of standoffs 220 includes one or more helical structures wrapping circumferentially around first tube 217 along a major length of the outside surface of first tube 217 and disposed on the inside surface of second tube 225. In another example, standoffs 220 comprise ribs or vanes extending parallel to the long axis A of ground probe 124 that are radially offset to allow working fluid 235 to pass from first working end 121 to second closed end 125. In other embodiments, standoffs 220 may be any suitable arrangement of structures spacing first tube 217 away from second tube 225 while also defining apertures through which working fluid 235 can pass. Some examples include washers, posts, o-rings or other suitable supporting structures circumferentially positioned around first tube 217, these structures defining holes or slots through which working fluid 235 may pass. Or in another example, standoffs 220 may be affixed to first tube 217 or to second tube 225 as well.

Working fluid 235 is therefore free to circulate through ground probe 224. In the heating mode, working fluid 235 moves along a first working fluid flow 211 as a relatively cool low pressure two-phase liquid and vapor combination entering second heat exchanger 120 from second line 117. Working fluid 235 moves through first tube 217 along first path 210 where the liquid phase pools in a mixing region 214 near second closed end 125 while the gas phase of working fluid 235 continues toward second compressor line 134 under suction from compressor 130. In mixing region 214, first path 210 couples with second path 212 allowing working fluid 235 to continue along separate second path 212. As working fluid 211 occupies second path 212, heat exchange occurs, for example, as heat from the ground around second heat exchanger 120 causes the liquid phase of working fluid 235 to evaporate from the liquid phase to a gas. These vapors move then along second path 212 in second working fluid flow 211 toward second reversing valve coupling 123 between the outside surface of first tube 217 (which may include insulative layer 219 as well) and the inside surface of second tube 225. The vapors are then reintroduced into compressor suction inlet 131 through second compressor line 134, compressed again, and reintroduced into first heat exchanger 110 and the cycle is repeated.

In the cooling mode, working fluid 235 enters second heat exchanger 120 as a relatively hot high pressure vapor arriving from second compressor line 134. The high pressure, high temperature working fluid 235 occupies second path 212 between the outside surface of first tube 217 (possibly including insulative layer 219 as well) and the inside surface of second tube 225. Heat exchange occurs, for example, as working fluid 235 is disposed against the inside surface of second tube 225 and rejects heat through second tube 225 into the ground around second heat exchanger 120 thus condensing from a hot vapor to a relatively high pressure warm liquid. The condensed working fluid 235 passes along separate second path 212 in a second working fluid flow 213 into mixing region 214. The condensed liquid phase of working fluid 235 pools adjacent second closed end 125 distributing along the bottom inside surface of second tube 225. Working fluid 235 also flows through first path 210 following second working fluid flow 213 through first tube 217 finally exiting second heat exchanger 120 as a warm liquid phase at relatively high pressure. Working fluid 235 then continues through the closed loop where its pressure is reduced by first metering device 111 thus absorbing heat from air flow 114 via first heat exchanger 110 as described above.

It can be appreciated from the figures discussed thus far that heat transfer between the ground and the working fluid occurs as the portion of the working fluid in the second separate flow path 212 makes thermal contact with second tube 225. The ground rests against the outside surface of second tube 225 while heat is transferred through second tube 225 to or from the working fluid 235 disposed along the inside surface. To achieve a rapid heat transfer between working fluid 235 and the earth, second tube 225 may be constructed of any of a number of metals which transfer heat quickly such as copper or iron. For example, iron may be used to provide sufficient strength to facilitate the insertion of ground probe 124 into the ground by tamping or pounding. In this embodiment, it may be possible to insert ground probe 124 without drilling bore holes which must then be filled to remove air pockets around ground probe 124. Second tube 225 may be constructed of a metal that is predominantly iron, such as a metal containing over 50 percent iron, up to and including metals comprising 100 percent iron including ductile iron, wrought and tempered iron, either hardened or unhardened. Alloys which are predominantly iron which may also be used include various forms of steel which are sometimes over 90 percent iron. Some types of steel which may be used include high or low carbon steel, stainless steel, galvanized steel, tool steel, and other similar alloys including less than about one percent of elements such as manganese, silicon, nickel, titanium, copper, chromium and aluminum to name a few.

Thermal exchange between the working fluid and the earth may be enhanced by inserting ground probe 124 at an angle rather than level with the horizontal. Examples of this are illustrated in FIGS. 2A and 2C where a ground probe including a second heat exchanger 120 is positioned at a nearly horizontal angle between about zero and about four degrees from the horizontal. Other embodiments may be advantageously positioned at different angles. For example, a predominantly iron ground probe may be positioned at a nearly horizontal angle between about zero and about 25 degrees from horizontal. Other angles are considered as well and may be advantageous.

Besides adjusting the angle, or perhaps in concert with it, efficiency may also be improved by increasing or decreasing the level of the one liquid phase working fluid 235 pooling near second closed end 125. This may be achieved by, for example by reducing the size of first tube 217 as well as any additional size created by accompanying insulative layer 219 if it is present. Similarly, the end of first tube 217 positioned within mixing region 214 may be deflected toward the bottom inside surface of outer tube 225 such as by bending it or by adding an additional elbow element.

However, as it may be advantageous to increase thermal transfer between second path 212 and the ground, it may also be advantageous to reduce the thermal transfer between first path 210 and second path 212. As noted above, first tube 217 therefore may also include an insulative layer 219 such as a sheath or coating on the outside surface of first tube 217 as shown in FIG. 2A. In other embodiments, insulative layer 219 may also be a lining on the inside surface of first tube 217. Insulative layer 219 may be constructed of a material such as a polymeric or plastic material like Nylon, polyvinyl chloride (PVC), fiber glass, polyethylene, or polypropylene to name a few examples. In another embodiment, first tube 217 FIG. 2A also illustrates a number of spacers 227 positioned at intervals between first tube 217 and insulative layer 219. Spacers 227, first tube 217, and insulative layer 219 define one or more voids 230 between spacers 227 along the length of second tube 219. In this embodiment, voids 230 provide additional insulation further reducing the rate of thermal transfer between first path 210 and a separate second path 212. In yet another variation, voids 230 are substantially evacuated of air and other gases between first tube 217 and insulative layer 219 creating a near vacuum condition within voids 230 to further enhance the insulative quality of insulative layer 219. In this configuration, it may be advantageous to insert ground probe 224 into the ground at any angle from zero to 90 degrees from horizontal.

FIG. 2A also shows a first path size 222 and a second path size 223. As illustrated, first path size 222 is smaller than second path size 223. Various ratios of the size of second path 223 in relation to first path 222 are envisioned. For example, second path 223 may be one a half, two, or perhaps three inches in size while first path 222 might be one eight to one inch in size. Thus the ratio of the second path size 223 to the first path size 222 might vary between 24 to 1 and one and a half to one. Other embodiments are envisioned as well where the ratios may be larger or smaller where it may be advantageous to use an even larger second path size 223 with an even smaller first path size 222, or a second path size 223 that is even closer to first path size 222.

FIG. 2B is a cutaway cross-section taken along the line BC in FIG. 2A. First tube 217 is shown within second tube 225, both having a substantially circular cross-section. Other cross sectional shapes are also envisioned whereby ground probe 124 may be constructed of tubing having a square, ovular, rectangular, or other geometric cross-sections. Similarly, other embodiments of ground probe 124 may be configured as a single segmented tube defining a first path and a second separate path using segments within a single tube rather than a first tube within the second tube as shown.

Also shown in FIG. 2B are spacers 227 between insulative layer 219 and first tube 217. Similarly, standoffs 220 are illustrated in FIG. 2B as a ring positioned circumferentially around first tube 217 and insulative layer 219. As shown, standoffs 220 define multiple apertures or holes for allowing working fluid 235 to pass through as discussed above.

FIG. 2C shows another embodiment of a second heat exchanger at 204 similar to the embodiment shown in FIG. 2A. However, in FIG. 2C, a first tube 218 operates as a metering device or expansion valve configured to accept first working fluid flow 211 in the heating mode. Included with first tube 218 is insulative layer 219, here embodied as a sleeve on the outside of first tube 218. Insulative layer 219 may also be positioned inside first tube 218 as well, or spaced away from first tube 218 as described above.

First path 210 is larger at first working end 121 than at second closed end 125 and reduces in size along the length of first tube 218. In the illustrated embodiment, first tube 218 has one or more narrowing regions 224 reducing its size 222 and therefore reducing the pressure of working fluid 235. As working fluid 235 passes out of path 210 into the coupling region 214, the pressure of working fluid 235 is reduced and its volume expands forming a two-phase liquid and gas combination at a relatively low pressure and reduced temperature. The liquid phase of working fluid 235 pools in mixing region 214 from which it can be evaporated into a gas as it is warmed by heat from the earth around the outside of ground probe 124. Working fluid 235 can then be drawn into compressor 130 through second compressor line 134 and the cycle repeated as described above.

Illustrated in FIGS. 3A and 3B at 300 and 305 are examples of a ground probe heating and cooling system 100 installed in a building. One example of a basement installation of a ground probe heat pump system is shown at 300. A nearly horizontal ground probe heat pump system 100 illustrated in FIG. 1 is installed in a building 310 which includes at least one above ground room 317 and at least one below ground room 312 such as a basement room. It should be noted that FIG. 3A is a diagram representing any type of building with at least one room below ground level, and at least one room above ground. Examples of building 310 include a single story home, a multi-story home, a multi-unit building such as an apartment complex or duplex, a commercial structure such as a office building having one or more floors, a warehouse, factory, or shopping center, or an entertainment facility such as a theater or sports arena, to name a few.

Below ground room 312 includes a wall 322 through which ground probe 124 is inserted into the earth 142 outside room 312. Heat pump system 100 is mounted to wall 322 on mounting bracket 140 as illustrated in FIG. 1 and operates as described above. Ground probe 124 is inserted through basement wall 322 into the earth 142 at a nearly horizontal angle of insertion 316 which may be any angle 25 degrees or less from horizontal, preferably one half to four degrees below horizontal, most preferably one and a half degrees below horizontal.

As discussed above, the heat pump system 100 includes lines 116 and 117 which are here coupled to a first heating and cooling system 313, a second heating and cooling system 315 or to both systems as further illustrated in FIG. 4A. First heating and cooling system 313 includes one or more ducts 115 for carrying heated or cooled air throughout building 310. In the embodiment shown, controller 150 is coupled to heating system 313 and heat pump system 100 to operate both systems in concert to adjust the temperature of the air inside building 310. Controller 150 may include various controls for allowing a user to set one or more temperature setpoints for maintaining a given air temperature within building 310. First heating and cooling system 313 may then be controlled by controller 150 to turn on or off, switch from heating mode to cooling mode, increase or decrease fan speeds, or perform various other functions for adjusting the temperature of the air within building 310. Second heating and cooling system 315 may also be coupled to controller 150 in the case where no first heating and cooling system 313 is present.

However, in another embodiment illustrated in FIGS. 3A, 3B, and 4A, second heating and cooling system 315 has a separate control line 325 coupled to a second controller 327 independent of first controller 150. In this configuration, second heating and cooling system 315 operates as a detached unit from first heating and cooling system 313 and may be positioned independently with in separate rooms in building 310. Controller 327 may be a thermostat like controller 150, a mechanical switch, or any other device suitable for activating and deactivating the pump system 100. As with controller 150, controller 327 may include various buttons, dials, switches, or other controls for allowing a user to set one or more temperature setpoints. Second heating and cooling system 315 may then be controlled by controller 327 to turn on or off, switch from heating mode to cooling mode, increase or decrease fan speeds, or perform various other functions for adjusting the temperature of the air within room 312 for building 310.

Another example of an installed nearly horizontal ground probe heat pump system 100 is shown in FIG. 3B at 305 where building 311 has a crawl space 320 instead of a below ground room 312. In this configuration, first heating and cooling system 313 and second heating and cooling system 315 are not located in the same room with compressor 130 but are coupled to it by lines 116 and 117. Ground probe 124, is inserted through supporting structure 323 into the earth 142. As described above with respect to FIG. 3A, first heating and cooling system 313 includes ducts 115 carrying conditioned air throughout building 310 while second heating and cooling system 315 provides a similar function within a given room separate from first heating and cooling system 313. For example, some installations may not include a first heating and cooling system 313 with ducts. In this case, building 310 may include multiple secondary detached heating systems 315 positioned in and around building 310 providing heating or cooling in the one or more rooms 317. For example, it may be advantageous to install multiple ground probe heat pump systems 100 within crawl space 320 with multiple second heating and cooling systems 315 positioned nearby and above crawl space 320 in room 317.

One installation of multiple ground probe heat pump systems 100 is shown at 400 in FIG. 4A making reference to previous FIGS. 1, 3A, and 3B. FIG. 4A also illustrates one embodiment of how heat exchangers 110 could be positioned within first heating and cooling system 313 and second heating and cooling system 315 to create more than one air flow path within a building. As shown in FIG. 4A, probes 124A through 124D are positioned through wall 141 such as wall 322 in FIG. 3A, or supporting structure 323 in FIG. 3B. Wall 141 has the earth 142 adjacent outside surface 145 with the inside surface 144 defining a room within a building such as building 310 or 311 shown in FIG. 3A or 3B respectively. Compressors 130A through 130D are coupled to probes 124A through 124D respectively as illustrated in FIGS. 1, 2A, 2B and 2C, and described above. Lines 117A through 117D and 116A through 116D are coupled to first heat exchangers 110A through 110D to complete a closed loop containing a working fluid. Heat exchangers 110A through 110C are positioned within ducts 115 wherein air flow 114A is created by a main blower 405. First heat exchangers 110A are arranged to intercept airflow 114A and are used in conjunction with the rest of heat pump system 100 to heat or cool air flow 114A as discussed above with respect to FIG. 1. In the configuration shown, airflow 114A also passes through main heat exchanger 407 which is also positioned within an air flow 114A and is also configurable to either heat or cool air flow 114A.

Controller 150 described above is coupled to compressors 130A through 130C as well as to first heating and cooling system 313. In this configuration illustrated at 400, compressors 130A through 130C operate as an auxiliary heating system to operate in addition to heat provided by first eating system 313. For example, heat pump systems 100A through 100C may be configured to activate, altogether, one by one in stages, or in predefined groups, when the temperature change in the building exceeds a first preset high or low temperature threshold. This threshold might be set, for example, in controller 150. Controller 150, in this example, then activates and deactivates heat pump systems 100 by sending signals along control lines 151A through 151B to the respective heat pump systems as necessary to heat or cool the building. If the thermal load on the building causes the temperature to change beyond a second high or low temperature threshold (which may also be set in controller 150), the controller 150 can then activate first heating and cooling system 313 through control line 151D to operate in the appropriate mode to provide additional heating or cooling as necessary. First heating and cooling system 313, as well as one or more of the heat pump systems 100 may then be deactivated accordingly if and when the first high or low temperature thresholds are maintained.

FIG. 4A also includes additional detail regarding the installation and operation of second heating and cooling system 315. As with the heat pump systems 100A through 100C, heat pump system 100D is also configured with a probe 124D inserted through wall 141 into the ground 142. Lines 117D and 116D couple compressor 130D to first heat exchanger 110D located in an enclosure 410 having a blower 408. Blower 408 creates air flow 114B passing through first heat exchanger 110D which then enters the building. As shown in FIGS. 3A and 3B, a control line 325 couples second heating and cooling system 315 to heat pump system 100D. Controller 327 is located within enclosure 410 and is coupled to heat pump 100D through a control line 325. In this configuration, second heating and cooling system 315 illustrates an embodiment of a heat pump 100D operating as a heating unit with an air flow 114B separate from air flow 114A moving through duct 115. Thus FIG. 4A shows an example of multiple heat pump systems (such as three or more) mounted within a room, either in a duct (115) or in a separate enclosure (410) configured to heat or cool one or more rooms inside a building such as building 310 or 311.

FIG. 4B illustrates at 405 a second embodiment of duct 115 and first heat exchangers 110A through 110C operating along with heating first heating and cooling system 313. In the illustrated configuration, ducts 115A through 115C contain first heat exchangers 110A through 110C. Each duct 115 A through 115C also contains an auxiliary blower 406A through 406C for directing individual air flows 412A through 412C air through heat exchangers 110A through 110C on a separate paths from air flow 114A created by main blower 405. Flow valves 420A through 420C are positioned to allow air flows 412A through 412C when auxiliary blowers 406A through 406C are activated, and to close when they are deactivated to avoid circulations of air through ducts 115A through 115C when heat pump system 100A through 100C are not active. In this configuration, heat exchanger's 110A through 110C heat individual flows of air positioned to recombine to form a supply air flow 417 which then enters a building such as building 310 or 311 and into the one or more rooms like room 312 or 317. In another embodiment, ducts 115A through 115C are positioned at various locations around a building such as 310 or 311 and are not positioned close to main blower 405 in order to better provide heating and cooling in particular locations with the building.

Installing heat pump systems 110A through 110D in FIG. 4A can be accomplished by first making openings in 146A through 146D in wall 141 large enough to allow ground probes 124A through 124D to pass through. Then ground probes 124A through 124D may then be aligned at the proper insertion angle 316, and inserted into the earth 142. The insertion may be performed by, for example, applying pressure to the first working end 121 of each ground probe 124A through 124D. In one example, pressure is applied by repeated hammering, pounding, or tapping with a hammer, maul, or similar device. In this embodiment of the procedure, mounting bracket 140, or another similar alignment device having a guide 143 inclined to the proper insertion angle may be used to aid in maintaining the desired angle of insertion during installation. Also, the outer surface of second closed end 125 of ground probe 124 may be substantially perpendicular to the long axis A of ground probe 124 to aid in the proper alignment of ground probe 124. In this way, ground probe 124 will be less likely to deviate from the desired angle of insertion 316 as it is inserted into the earth 142. The process is repeated for each ground probe 124A through 124D.

When ground probes 124A through 124D are inserted, the first working end of each ground probe 124 may be coupled to mounting bracket 140, and mounting bracket 140 secured to wall 141. The rest of heat pump system 100 may then be coupled together as discussed above coupling compressor 130, first heat exchanger 110, and second heat exchanger 120 together in a closed loop. Working fluid 235 may then be introduced into the closed loop. These steps, and others, are then repeated for each heat pump system 100A through 100D.

Claims

1. A nearly horizontal ground probe heat pump, comprising:

a first heat exchanger;

a compressor;

a second heat exchanger including a probe having a first working end, the probe defining a first path and a separate second path coupled to one another near a second closed end positioned in the earth;

a working fluid; and

a closed loop including the first heat exchanger, the compressor and the second heat exchanger, the closed loop containing the working fluid;

wherein the probe is inclined from one half to four degrees below horizontal.

2. The ground probe heat pump of claim 1, wherein the first path is smaller than second path.

3. The ground probe heat pump of claim 2, wherein a ratio of a second size of the second path to a first size of the first path is between about 25 to 1 and about one and a half to one.

4. The ground probe heat pump of claim 1, wherein the second path is defined by a predominantly iron tube.

5. The ground probe heat pump of claim 3, wherein the predominantly iron tube is predominantly steel.

6. The ground probe heat pump of claim 1, wherein the first path has a substantially circular cross section.

7. The ground probe heat pump of claim 1, wherein the first path is defined by a first tube, and the second path is defined by a second tube and the first tube is positioned within the second tube.

8. The ground probe heat pump of claim 7, which additionally includes a standoff to space a major length of the first tube away from an inside wall of the second tube.

9. The ground probe heat pump of claim 7, wherein the first tube includes an insulative layer.

10. The ground probe heat pump of claim 1, wherein an outer surface of the closed second end is substantially perpendicular to a long axis of the probe.

11. The ground probe heat pump of claim 1, wherein the first working end is in a room of a building.

12. The ground probe heat pump of claim 11, wherein the room is a basement room.

13. The ground probe heat pump of claim 11, wherein the room is a crawl space.

14. The ground probe heat pump of claim 1, wherein the compressor and the first working end are mounted on a bracket.

15. The ground probe heat pump of claim 1, wherein the working fluid is any one of R-22, R-22A, R-134A, or R-410A.

16. A predominantly iron ground probe heat pump, comprising:

a first heat exchanger;

a compressor;

a second heat exchanger including a predominantly iron probe having a first working end, the probe defining a first path and a separate second path coupled to one another near a second closed end positioned in the earth;

a working fluid; and

a closed loop including the first heat exchanger, the compressor and the second heat exchanger, the closed loop containing the working fluid;

wherein the probe is 25 degrees or less from horizontal.

17. The ground probe heat pump of claim 16, wherein the first path is smaller than second path.

18. The ground probe heat pump of claim 17, wherein a ratio of a second size of the second path to a first size of the first path is between about 25 to 1 and about one and a half to one.

19. The ground probe heat pump of claim 16, wherein the predominantly iron probe is predominantly steel.

20. The ground probe heat pump of claim 16, wherein the first path is defined by a first tube, and the second path is defined by a second tube, and the first tube is positioned within the second tube.

21. The ground probe heat pump of claim 20, which additionally includes a standoff to space a major length of the first tube away from an inside wall of the second tube.

22. The ground probe heat pump of claim 20, wherein the first tube includes an insulative layer.

23. The ground probe heat pump of claim 16, wherein the first working end is in a room of a building.

24. A multiple ground probe heating and cooling system for a building, comprising:

three first heat exchangers positioned in the building;

three compressors;

three second heat exchangers, each second heat exchanger including a probe having a first working end, the probe defining a first path and a separate second path coupled to one another near a second closed end positioned in the earth; and

three separate closed loops including a corresponding first heat exchanger, compressor and second heat exchanger respectively, the three separate closed loops each containing a working fluid;

wherein the probe is 25 degrees or less from horizontal.

25. The ground probe heating system of claim 24, wherein the first path is defined by a predominantly iron tube.

26. The ground probe heating system of claim 25, wherein the predominantly iron tube is predominantly steel.

27. The ground probe heating system of claim 24, wherein the first working end is in a room of a building.

28. The ground probe heating system of claim 27, wherein the room is a basement room.

29. The ground probe heating system of claim 27, wherein the room is a crawl space.

30. The ground probe heating system of claim 27, wherein the three first heat exchangers are in a second room.

31. The ground probe heating system of claim 27, wherein one of the first heat exchangers is in the room, and one of the first heat exchangers is in a second room of the building.

32. The ground probe heating system of claim 27, wherein the three first heat exchangers are in a duct in the room.

33. The ground probe heating system of claim 24, wherein the compressors and the first working ends are mounted on brackets.