CA2150272A1 - Geothermal fluid heating device - Google Patents

Abstract

A heating device which transfers the available energy via a fluid (chemical compound) from the natural thermal energy collected in sub surface elements. This positive energy is then used to displace negative energy from within the structure via a primary heat exchange which is by high/low press. high temp./low temp. reduced temp. and cross flow energy methods. The system is based on five parts or steps: 1) extraction of available energy, indoor heat exchangers or condenser, 2) fluid transfer device or compressor pump or circulation system for available energy. The circulator, a scroll compressor is used strictly to circulate the fluid and not necessarily to increase the entropy of the fluid, 3) collector or evaporator ground transfer unit or earth energy extractor. A horizontal collector or extractor which is a combination of individual pipes collected from a common header and reconnected at another common header which is located inside the building, 4) transfer medium or fluid, and finally 5) control system.
The system eliminates the need for various heat exchangers and condenses the amount of transfers of energy required in order to make the available energy usable. The fluid being returned to the earth is subcooled by way of mechanical means and ambient means and restricted from an occurrence of backflow.
The fluid is constricted by the use of a small diameter series of pipes. It is using the new energy available from the extractor rather than the increase of temp/press. mechanical process of the compressor (heat process). The collection of energy being by low intensity methods. It is utilizing the latent heat gain of the fluid from the ground coil. The system is designed so that it does not require a restriction device in order to change transition the fluid and in most cases maintains a thermal head on the outlet side of the ground extractor. The temperature difference between the collector and the indoor unit is reduced as much as possible in order to maximize the efficiency of the system. This high efficiency heating system is competitive in terms of installation cost, and operating energy cost of other available energy sources.

Description

215~27~

" In drawings which illustrate embodiments of the invention, brief description of the drawings, The drawings represent 7 parts of the system.
The first figure 1 is showing the overall closed circuit of the system.
The second figure 2 is showing the indoor heat extractor setup.
The third figure 3 is showing the primary heat extractor assembly.
4 The fourth figure 4 is showing the top view of the collector.
The fifth figure 5 is showing the outdoor inlet common header and the lines of the collector, along with top views of the plates located inside the header.
The sixth figure 6 is showing the collector from a side view.
The seventh figure 7 is showing the indoor common return header.
The drawings are all identified with markings to match the description.

Description, specifications : A heating only system which absorbs the stored energy from the earth and transfers it to a coil system. This system is assembled to provide new energy in the form of heat to a structure or a zone of that structure more efficiently than existing heating systems that burn hydrocarbons. A fluid ( chemical compound of non ozone depleting mixtures ) is circulated through a closed system. The complete system is a sealed or closed system. The fluid is in direct contact with the extractor and the collector parts of the 5 system, through the walls of a highly conductive metal (copper).
This system utilizes the natural solar storage capabilities of the thermal mass of the earth, to provide new energy which is picked up by the collector (drawing figure 1).
A heating device which transfers the available energy via a fluid (chemical compound) from the natural thermal energy collected in sub surface elements. The heat transfer medium is a commonly used refrigerant. This positive energy is then used to displace negative energy from within the structure. The system eliminates the need for various heat exchangers and condenses the amount of transfers of energy required in order to make the available energy usable (claim 1). The system can be divided by 5 parts of which the most important is based on the first three parts or steps:
Part 1) extraction of available energy; (drawing figure 2) indoor heat exchangers or condenser, a primary heat exchanger (1 a) which is using high/low press. high temp./low temp. reduced Pqg~ 5 temp. and cross flow energy methods. It is using the new energy available from the extractor (3) rather than relying on the increase of temp/press. mechanical process of the compressor (2) (heat process), therein increasing the mass flow rate of the system (claim la) and thus the efficiency the indoor extractor (1) which consists of four heat exchanges. The first exchange (1 a) is by introducing the fluid which is passing at approx. 80 deg. F. from the compressor (2) enters the top of the exchanger (1 n) (drawing figure 3) where a second wall of 60 - 70 deg.
6 water at a pressure of 60 p.s.i.g. condenses the fluid (4) (claim lb). The water which is circulating by way of a pump (1 f) continuously, passes through the route (1 g) from the bottom of (1 a) upwards and carries any excess or sensible heat gain (claim lc) to the bottom of the secondary (1 h) where another exchange (1 b) occurs with the water and the cooled basement air. The water circuit exits the top of this exchanger (1 i) and continues to the storage units (1 j) where the lines enter the top of the tanks (1 k) and ( 1 1). The third (1 c) heat exchange occurs here (claim 1 d). The circuit continues back to (1) via the bottom of the storage units (1 m) through the pump (1 f) and continues again through the circuit. The chemical compound which continues counterflow to the water circuit through the primary extractor (1 a) in a serpentine circuit and passes along all the circuits until it is collected at the bottom of the exchanger where it exits through the outlet line (1 e) (claim 1 e). The complete system is housed along with the electrical, mechanical pqge 6 215~272 parts, and the heat extractors in a casing that is open to the basement on the one end, and connected if available by a 15 in., 38.1 cm. round duct to the main return air duct of the central forced air heating plant (1 d) (claim 1 f). This final heat exchange (1 d) with the return air of the building and the primary heat exchanger (1 a) carries the new energy to the areas required.
Part 2) fluid transfer device or compressor pump or circulation system for available energy. The circulator, a 7 scroll compressor is used strictly to circulate the fluid and not necessarily to increase the entropy of the fluid (4). (claim 2 ).
Part 3) collector or evaporator ground transfer unit or earth energy extractor. A sub surface horizontal collector or extractor (3) which is a combination of individual pipes collected from an outside common inlet header (3 a) and reconnected at another inside common return header (which is located inside the building)(3 h). The size of the area (3 i) used for the collector is approx. 1100 sq.ft.102.2 sq.m. This can be reduced by compressing the distance between the lines (drawing figure 4). The outside common inlet header (3 a) which is located on the outside wall at the start of the common trench is connected to the 1/2 in.,1.27 cm. outlet line (1 e) of the indoor heat extractor. This line leaves the indoor unit (1), rises and follows the contour of the basement ceiling and exits the building at the point where the outside common inlet header ~CI9~ 7 215~272 is placed on the outside wall. The outside common inlet header (2 1/8 in. x 30 in.long) is placed at a level that is the highest point in the complete system usually at the same level as the basement ceiling. The outside common inlet header is placed so the unit stands vertical to the floor of the building.
This header is of special design (claim 3a). The pipes (3 b) (lines) feeding the sub surface collector are connected to this header (drawing figure 5). The lines (3 b) are installed with backflow or check valves (3 c) and shutoff ball valves (3 d) which can isolate the lines if need be (claim 3b). The 10 horizontal lines are placed 2 ft..609 m. apart in the excavation. Each line extends to minimum 24 to 35 ft.,7.31 m. to 10.67 m., out from the common trench line. Each line which is round in design and has a outside diameter of approx. 3/8 (.375 "),0.9525 cm. is distributed with the inlet at a level lft.,.305m, above that of the bend or return (claim 3 c). The bend is 30 times the diameter, or 12 in.,30.48 cm., the inlet is above the return of the same line and the lines run parallel.
The inlet lines are insulated for 6 ft.,1.83 m. beginning from the common inlet header starting approx. 6 in.,15.24 cm. above ground level and the return lines are insulated for 12 ft.,3.66 m. ending at the inside common return header just outside the foundation wall. The insulation is minimum 3/8,.9523 cm. wall.
The lines 1, 2 are 66 ft.,20.12 m. total length, The lines 3, 4, 5, 6, 7, 8, are 132 ft.,40.23 m. total and the final 9, 10, are 160 ft.,48.77 m. total length. For a total of 1244 ft. or 379.17 ~qg~ 8 21~0272 -m. (claim 3 d). All lines are placed together in the common trench area so as not to be touching but without concern if after settling occurs movement shifts their positions. The lines are placed in the excavated area along the contour as explained (claim 3 e). The common trench (3 e) which is used to carry the tubing (piping) to the exchange or collector zone (3) can vary in length depending upon the obstructions. It should allow for a minimum collector length per line of 24 ft.,7.32 m. The common trench which is running from the foundation wall is approx. 3 9 ft.,.914 m. wide and opened from grade level down to 1 ft.,.305 m. above the base of the foundation wall or basement floor running away from the structure approx. 9 ft.,2.74 m. max. The end or throat can be widened to allow for space between exposed tubing. The common trench is lowered in depth (which is usually 3 - 4 ft., .914 - 1.21 m. at the foundation wall) in steps (3 f) that are dug out of the ground each step approx. 3 ft.,.914 m.
wide and 16 in.,40.6 cm. deep or an equal depth to the level of the collector excavation which is at 6 - 7 ft.,l.83 - 2.13 m.
below grade (drawing figure 6)(claim 3 e). An opening (3 g); in the foundation wall, 31 to 36 in.,78.7 to 91.44 cm. above the basement floor and approx. 5 in.,or 12.7 cm. in diameter is required to route all 10 return lines to the inside return common header. The wall if hollow, is re insulated before sealing. The indoor common return header (3 h) (drawing figure 7) is located on the inside of the building opposite the opening (3 g). This header collects the returning lines that enter the ~ge 9 215~272 building. The 2 1/8 in. diameter header stands 30 in.,76.2 cm.
vertically. The returning lines are connected to the bottom of the header as shown. The return outlet line (3 j) which is 7/8,2.22 cm. outside diameter is extended down into the header 5 in.,12.7 cm. through the centre of the top cap of the return header and runs vertical to the floor up to the ceiling area where it follows the outlet line (1 i) back to the indoor extractor (1). These two pipes are brought together, tied and then insulated with standard 3/8 in., .9525 cm. wall insulation. The excavation site (3 i) is returned to original with the use of soil removed in the excavation, there is no need for use of increased thermal conductivity materials.
Part 4); The fluid or thermal transfer medium is a chemical compound that is a commonly available product (claim 4).
Part 5); The control of this system is by standard thermostat located in the same area as the primary heating system. A
computer control system could be incorporated to balance the system better (claim 5a).
This high efficiency geo thermal heating system is competitive in terms of installation cost, and operating energy cost of other available energy sources.

pq9~ 10

Claims (3)

1. Claim 1 ); The system reduces the number of exchanges which means; a reduction in conversion of this energy increases the efficiency and the energy retained. This system is moving the energy available in the earth, not necessarily by converting it to heat. Since the infiltration of colder outside air (heat loss) is degrading the air temperature of the home; as long as the new energy is available above the temperature of the infiltration air temperature it is usable to displace the total heat load.
   Claim 1 a); Since there is no restriction (evaporative valve) in this system the mass flow rate is not limited by restriction.
   The evaporator valves in most refrigeration systems are used to create a low pressure zone and thus increase the load on the compressor, thus raising the outlet temperature of the fluid.
   This is not necessary with this system, since the scenario is created by other means.
   Claim 1 b); The new energy made available from the collector is extracted at the indoor coil by the opposite forces in the water being circulated and the differences in the circulating air. The lower pressure, the lower temperature, the enthalpy, the flow of the water is set to create an efficient exchange of the energy available in the fluid. The water pressure is set high enough to create a good stress (thermal contact) on the walls to improve the conductivity of the copper, the temperature of the water is lower than that of the fluid to create the negative or the direction of flow of heat. The water which is moving in a direction opposite the fluid creates a cross flow situation for heat exchange or the latent heat exchange or condensing of the fluid. When the system is first started the first heat exchange (stress area) is small and limited at the point of hot to cold.
   However, as the static pressure builds this area expands in both directions of the fluid flow and of the water flow. The longer the cycle, the more area of the heat exchanger required in order to complete the thermal exchange of the fluid.
   Claim 1 c); Once the phase transition of the fluid occurs and the latent heat exchange has occurred, the fluid temperature contains only sensible heat properties. This remaining temperature which is transferred to the water, can prewarm the air entering the primary heat extractor area. The superheat created by the compressor can also be transferred better via the water by sensible heat gain. As the temperature in the outside collector decreases the phase transition of the fluid changes, creating a lack of fluid (refrigerant) at the outlet of the collector and thus superheat from the compressor.
   Claim 1 d); The water temperature will drop and release any temperature gained during the circuit. It is mixed with the storage units or possible by a loop buried in the floor which is a cold sink. The longer the cycle the less effective this exchange since its storage is by natural process and takes more time to readjust (thermally). The overall thermal condition of this storage effects the return water and thus the efficiency of the primary heat exchange.
   Claim 1 e); The fluid temperature will decrease as it passes along the heat exchanger from 80 deg.F.,26.6 deg.C. down to an outlet temperature of as low as 60 deg.F.,15.5 deg.C. The fluid at this point is a combination of vapour and liquid. Since this temperature can still be used, the inlet and return lines connecting the collector and extractors are tied together, however, there is very little exchange at this point.
   Claim 1 f); The extractor is using the colder heavier air which is naturally falling to the basement to create a heat exchange between the water and the air, it is also connected to the return air trunk line to create a static pressure or negative wash on the coil. The round duct is large enough in most cases to prevent high velocity, or high cfm movement through, while creating an access point for the new energy to be introduced to the areas of the home. The coil is more effective with less static, less cfm, less velocity and slightly increased face area.
2. Claim 2 ); The consideration for the sizing of the pump is the cfh capacity since the collector temp. is usually low point 30 to a high point 52 deg. F. The collector system (3) is designed to create a positive head pressure on the compressor system and has a more than adequate capacity in terms of quantity of fluid and enthalpy of returning fluid (potential energy). Most mechanical compressors exposed to the refrigeration cycle (carnot cycle) experience losses in exchange of the form of energy, the degradation of energy, and practical limitations.
   This system lowers the outlet temperature to approx. 80 deg.F.
   26.6 deg.C. and with the average ground supply temperature of approx. 45 deg.F., 7.2 deg.C. as well no restriction or expansion device in the system, the efficiency is increased. The compressor is no longer a heatpump per say as much as a thermal or energy pump. The electrical energy required to operate the pump is reduced and the pump operates at a cooler casing temperature which is closer to the room temperature. This prevents losses of the available energy.
   Claim 3a; The fluid being returned to the earth is subcooled by the common inlet header. This header works by way of mechanical means and by the ambient temperature of the air. It has internal fins which by converting the unusable heat energy to mechanical energy process reduces flash gas, fluid in gaseous state, reduces the pressure of the fluid to below that of the ground, stabilizes the flow of the fluid, improving the efficiency, the thermal transfer capacity or enthalpy of the fluid and the overall surface contact area required for the collector. This also corrects a volume variance which is common to geothermal heatpump systems. This common inlet header replaces the action of the usual expansion device or solenoid found in most refrigeration systems. The system is designed so that it does not require a restriction device in order to change transition the fluid and in most cases maintains a positive thermal head on the outlet side of the ground collector. This thermal exchange method of the returning gas is key to its capability for increased efficiency, less fluid required, control of the thermal state of the fluid, liquidfaction of the fluid for maximizing the heat absorbtion rate during a pass through the collector. It is creating a condition that expands the efficient enthalpy gain of the fluid during a phase transition before entering the ground collectors. This design is also stopping any degradation of the available energy by introducing a fluid which is at a lower pressure, temperature than the mass of the earth since the fluid temperature could be as high as 60 - 70 deg.F., 15.5 - 21.1 deg.C. in some other systems. The liquid is able to absorb more heat per degree of ground temperature than a uncontrolled mixture of gas, liquid as in most systems. This prevents the freezing of the collector as when the system is operating the complete system is equalized in pressure (Pascal's Law) rather than lowered by a restriction device. Since the ground temperature when lowered will reduce the overall capacity of the system and beyond a certain temperature will no longer provide enough temperature to change transition the fluid it is more productive for long term use of this system to draw the energy available by low intensity rather than extreme pressure, temperature differences.
   Claim 3b; This one way valve on each line prevents the natural losses created while the system is off. As the outside ambient becomes lower than the ground temperature a natural reversal of the fluid results in lowering the potential energy available in the geo thermal collector. The check valves will prevent any vaporized fluid from returning to the outdoor inlet common header and condensing, releasing the energy already obtained from the ground coils.
   Claim 3c; The smaller diameter piping creates a compressed area, limits the ability of the fluid to expand and decreases the area available for non thermal contact to the ground. The piping is located at the lowest point in the system, which is where liquid will naturally migrate to and is in the lowest pressure zone. The smaller piping draws the energy available by low intensity methods, radiation; rather than by possibly freezing or changing the temperature of the ground. Since there are natural losses in the thermal mass of the earth by colder air, and snow in the heating season the lines are located at a level 6 ft - 7 ft., 1.83 m - 2.14 m. The fluid by nature of its principals will try to absorb as much heat as possible and vaporize to the highest point. The smaller diameter piping will also present a scenario where the fluid may be as close as possible to its bubble point.
3. Claim 3 d; The contact surface area (thermal contact) which is most important, would allow for changes to the lengths depending upon the trenching layouts from the common trench line. The most important factor being the total contact surface area of the total length of pipe and not so much as the total earth or ground area used.
   Claim 3 e; The piping is lowered in steps to agitate the flow of the fluid thus improving its overall thermal capacity, thermal contact and wall conductivity.
   Claim 4; The designed system compensates for several properties and characteristics that are common to the chemical compound. The total charge of refrigerant is 7 lbs. for this system. The type of refrigerant is a commonly used compound available in the marketplace. It can either be HCFC 22 for the immediate future or an appropriate equivalent or replacement.
   These systems operate at a low evaporator pressure/temperature and are subject to reduction in the phase transition. Some systems try to compensate by overcharging the closed system, however, this creates a requirement of a huge storage of fluid, sometimes upwards of 15 lbs. in some cases. This system draws the available energy by low intensity, constricts the collector, subcools the fluid, manages the latent heat release better, controls the flow and state of the fluid, creates a thermal head on the outlet side of the ground extractor and allows the chemical compound the ability to expand, vaporize, rise and absorb the highest possible enthalpy.
   Claim 5 a; A short cycle in warmer weather is better for utilizing the load available and this also allows a release of energy upon shutdown. The normal thermostat although working on temperature drop for heating, adjustment by a heat anticipator can be considered by the minute based on the heat loss per hour of the structure to the outside temperature divided by 60 minutes which when calculated by the minute if the capacity of the pump is higher will determine its length of run time. For instance if the heat loss is 50,000 btuhr. at 0 deg. F. then 833 btu/minute the heat pump should be capable of providing at least the 833 btu/minute, but better if it can provide 1166 btu/minute or 70,000 btu/hour. This would insure that the system will cycle over a period of the hour and would be able to recover any extreme heat losses created. The anticipator is set for .15 to .2 amps.