JP2006313034A - Geothermal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a geothermal heat utilization device which can be operated with high efficiency and can be cost-effective with good workability.
A ground heat exchanger (2) and a heat pump (3) are connected by a primary refrigerant pipe (5), and heat is supplied from the natural refrigerant in the primary refrigerant pipe (5) to the air conditioning indoor unit (4) side through a primary condenser / evaporator (9). Since the heat is absorbed from the air conditioning indoor unit 4 side by the natural refrigerant in the supply or primary refrigerant pipe 5, the energy required for circulation is less than in the case where the heat transfer water is circulated by the circulation pump on the primary side. The energy efficiency of the entire air conditioning device 1 can be sufficiently increased. Furthermore, since the underground heat exchanger 2 and the heat pump 3 are connected by the primary refrigerant pipe 5, it is possible to improve the workability of the pipe as compared with the case where these devices are connected by the water pipe. At the same time, construction costs can be reduced.
[Selection] Figure 1

Description

  The present invention relates to a geothermal heat utilization device, and more specifically, uses geothermal heat collected (or radiated) from a ground heat exchanger embedded in the ground and supplies heat to a load side via a heat pump ( Or, it relates to a geothermal heat utilization device that absorbs heat from the load side.

A geothermal heat utilization device comprising a ground heat exchanger buried in the ground, a heat pump connected to the ground heat exchanger, and a heat exchanger such as an air conditioner connected to the heat pump is known. (For example, refer to Patent Document 1).
Such a heat pump system using geothermal heat uses ground heat having a stable temperature as a heat source, collects and radiates heat from this heat source, and uses an air heat source system that collects and radiates heat from outside air. Compared with this system, it is a system that can be operated with high efficiency for both cooling and heating by utilizing a stable underground temperature with little change throughout the year. Therefore, in the heat pump system using geothermal heat, in addition to effects such as energy saving, low running cost, and carbon dioxide emission suppression, the heat island phenomenon is also expected to be suppressed by not exhausting heat to the atmosphere.

  In the underground heat utilization device described in Patent Document 1, the underground heat exchanger and the heat pump are connected by a first circulation path including a water pipe, and the heat pump and the heat radiating pipe are connected to a heat medium pipe (such as water). Hereinafter, it is connected by a second circulation path consisting of water piping), and a third circulation path consisting of refrigerant piping is provided inside the heat pump. During heating, the ground heat is collected by the first heat medium circulated in the first circulation path, and this heat is absorbed by the third heat medium (refrigerant) in the third circulation path. The second heat medium is supplied to the second heat medium in the circulation path to raise the temperature of the second heat medium so that the heat is radiated from the heat exchanger. Conversely, during cooling, heat is dissipated from the first heat medium to the ground, the first heat medium absorbs heat from the third heat medium, the third heat medium is cooled, and the third heat medium and the second heat medium are cooled. The second heat medium is cooled by exchanging heat with the medium, and heat is collected from the conditioned space by the heat exchanger.

JP 2003-302122 A

However, in the conventional geothermal heat utilization apparatus as described in Patent Document 1, the first heat medium in the first circulation path is composed of heat medium water such as water or antifreeze liquid, and this first heat medium is used as a circulation pump. Therefore, there is a problem that the energy for driving the circulation pump on the heat source (primary) side becomes large and the efficiency of the operation energy in the entire device cannot be sufficiently realized. is there.
In addition, since the first circulation path is composed of water pipes, it is necessary to provide a water gradient in the pipes, to remove the air, and to connect the pipes with screws. There is also a problem that the construction cost increases with the deterioration.

  An object of the present invention is to provide a geothermal heat utilization device that can be operated with high efficiency and that can improve workability and reduce costs.

  The ground heat utilization apparatus of the present invention includes a ground heat exchanger embedded in the ground, a heat pump connected to the ground heat exchanger, a load machine connected to the heat pump, and the ground heat A primary side pipe connecting the exchanger and the heat pump, wherein the primary side pipe is a refrigerant pipe for circulating the refrigerant, and the heat pump exchanges heat with the refrigerant in the primary side pipe. A heat exchanger to be implemented is provided, and heat is supplied to or absorbed from the loader through the heat exchanger.

  Here, the loader is supplied from a heat pump (or absorbed by the heat pump) such as an indoor air conditioner that cools, heats, or cools the room, a refrigerated (refrigerated) refrigerator, a water heater, or a water heater. ) Various devices using heat can be exemplified.

According to the present invention described above, the primary side pipe connecting the underground heat exchanger and the heat pump is the refrigerant pipe, and heat is supplied to the loader through the refrigerant and the heat exchanger in the primary side pipe or the load machine. Therefore, the energy required for circulation can be reduced as compared with the conventional case where the heat transfer water is circulated by the circulation pump on the primary side. Therefore, the energy efficiency of the entire apparatus can be sufficiently increased.
Furthermore, by connecting the underground heat exchanger and the heat pump with refrigerant pipes, it is possible to eliminate the restrictions of connecting with water pipes as in the past, and to improve the workability of the pipes as well as the construction cost. Can be reduced.

Further, the geothermal heat utilization device according to claim 2 is the geothermal heat utilization device according to claim 1, wherein the refrigerant in the primary side pipe is at the time of heat collection from the geothermal heat exchanger. The refrigerant is naturally circulated by a change in specific gravity caused by gasification and liquefaction of the refrigerant.
According to such a configuration, at the time of heat collection, the refrigerant in the primary side pipe is naturally circulated with a change in specific gravity due to gasification and liquefaction, so that the energy required for refrigerant circulation can be further reduced and the energy efficiency of the entire apparatus can be reduced. Can be further improved.

Furthermore, the underground heat utilization apparatus according to claim 3 is the underground heat utilization apparatus according to claim 1 or 2, wherein the primary side pipe is branched into a heat radiation pipe and a heat collection pipe. These heat radiation pipes and heat collection pipes are switchable. The heat radiation pipes are filled with the refrigerant at a predetermined pressure, and the heat collection pipes include the heat radiation pipes. The refrigerant is sealed at a pressure lower than that of the refrigerant.
According to such a configuration, the heat radiation to the ground in the underground heat exchanger is achieved by enclosing the refrigerant at a predetermined pressure suitable for heat radiation or heat collection in each of the heat radiation pipe and the heat collection pipe. Efficiency or heat collection efficiency from the ground can be increased to further improve the operation efficiency of the apparatus. In addition, by appropriately adjusting the refrigerant sealing pressure in the heat collection pipe, the refrigerant cooled and liquefied by the heat exchanger of the heat pump naturally descends toward the underground heat exchanger and rises by the underground heat exchanger. The heated and gasified refrigerant can naturally rise toward the heat pump, and the refrigerant can be naturally circulated without using a circulation pump.

The geothermal heat utilization device according to claim 4 is the geothermal heat utilization device according to claim 1 or 2, wherein the pressure of the refrigerant in the primary side pipe is adjusted in the primary side pipe. Pressure adjusting means is provided, and the pressure adjusting means adjusts the pressure of the refrigerant in the primary side pipe at the time of heat collection lower than that at the time of heat dissipation.
According to such a configuration, during heat radiation or heat collection, the pressure of the refrigerant in the primary side pipe is adjusted to a pressure suitable for heat radiation or heat collection by the pressure adjusting means, so that the ground in the underground heat exchanger It is possible to further improve the operation efficiency of the apparatus by increasing the heat dissipation efficiency to the heat or the heat collection efficiency from the ground. In addition, by appropriately adjusting the pressure of the refrigerant in the primary pipe during heat collection, the refrigerant cooled and liquefied by the heat exchanger of the heat pump naturally descends toward the underground heat exchanger, and the underground heat exchange The refrigerant that has been heated and gasified in the vessel can naturally rise toward the heat pump, and the refrigerant can be naturally circulated without using a circulation pump.

Moreover, the underground heat utilization apparatus of Claim 5 WHEREIN: The underground heat utilization apparatus in any one of Claims 1-4 WHEREIN: The refrigerant | coolant in the said primary side piping is a carbon dioxide refrigerant. Features.
According to such a configuration, by using carbon dioxide refrigerant, which is a natural refrigerant, as the primary-side refrigerant, it is possible to reduce the refrigerant conveyance power as described above, and to reduce the environmental load.

Furthermore, the underground heat utilization apparatus according to claim 6 is the underground heat utilization apparatus according to any one of claims 1 to 5, wherein the primary side pipe is connected to the underground heat exchanger. The atmospheric heat radiation condenser and / or the atmospheric heat collection evaporator are connected to the heat pump in a switchable manner, and the atmospheric heat radiation condenser is stored in the ground by heat radiation from the underground heat exchanger. Excess heat is dissipated to the atmosphere, and the atmospheric heat collecting evaporator collects and supplies heat from the atmosphere to the ground whose temperature is lowered by the heat collection of the underground heat exchanger. .
Here, at least one of the atmospheric heat radiation condenser and the atmospheric heat collection evaporator may be connected to the primary side pipe, and both may be connected.
According to such a configuration, for example, the load machine is an air conditioner, the cooling load in summer is excessive, and the amount of heat released from the underground heat exchanger exceeds the amount of heat collected at the time of the heating load. If there is a possibility that the ground temperature may rise due to accumulation in the ground, switch the connection of the primary side pipe from the ground heat exchanger to the air heat radiation condenser side, and then remove excess heat in the ground. By radiating heat from the atmospheric heat radiation condenser to the atmosphere, it is possible to prevent an increase in underground temperature, and it is possible to perform heat radiation to the ground stably over a long period of time. On the other hand, if the heating load in the winter season is greater than the cooling load, the primary pipe connection from the underground heat exchanger is switched to the atmospheric heat evaporator side, and the heat collected from the atmosphere is By supplying to the ground, it is possible to prevent a decrease in the underground temperature and to perform heat collection from the stable ground for a long period of time.

Moreover, the underground heat utilization apparatus according to claim 7 is the underground heat utilization apparatus according to any one of claims 1 to 6, wherein the heat pump and the load machine circulate refrigerant. The heat pump is provided with a compressor that compresses the refrigerant in the secondary side pipe, and an expansion valve that expands the refrigerant in the secondary side pipe. The heat exchanger is a primary condenser / evaporator that condenses or evaporates the refrigerant in the secondary side pipe using the refrigerant in the primary side pipe, and the load machine is compressed by the compressor of the heat pump. There is provided a secondary condenser / evaporator for condensing the refrigerant in the secondary pipe having a high temperature, or evaporating the refrigerant in the secondary pipe having a low temperature expanded by an expansion valve of the heat pump. It is characterized by that.
Here, each of the primary condenser / evaporator and the secondary condenser / evaporator may condense the refrigerant in the secondary side pipe, may evaporate the refrigerant, and further condenses the refrigerant and function. It may have both functions of evaporating water. However, when the refrigerant is condensed by the primary condenser / evaporator, the secondary condenser / evaporator is configured to evaporate the refrigerant. When the refrigerant is evaporated by the primary condenser / evaporator, The secondary condenser / evaporator is configured to condense the refrigerant.

According to the above configuration, the heat pump and the load machine are connected by the refrigerant pipe, and the secondary condenser / evaporator is provided in the load machine. Therefore, the refrigerant in the primary side pipe by the heat exchanger that is the primary condenser / evaporator. The refrigerant in the secondary side pipe that has absorbed heat (or dissipated heat to the refrigerant in the primary side pipe) is conveyed to the load machine through the compressor or expansion valve and circulated. The secondary circulation pump can be dispensed with. In addition, since the refrigerant is circulated directly from the primary condenser / evaporator of the heat pump to the secondary condenser / evaporator of the load machine, heat exchange to the heat transfer medium on the load side is unnecessary, and losses due to heat exchange are minimized. can do. Accordingly, the thermal efficiency can be further improved and the driving energy of the secondary circulation pump can be omitted, so that the energy efficiency of the entire apparatus can be further increased.
Furthermore, by connecting the heat pump and the load machine with the refrigerant pipe, the workability of the secondary pipe can be improved, and the construction cost can be further reduced.

Furthermore, the geothermal heat utilization apparatus according to claim 8 is the geothermal heat utilization apparatus according to claim 7, wherein the plurality of load machines are connected to the heat pump, and the plurality of load machines are simultaneously used. Alternatively, for each of the plurality of load machines, the operation and stop can be switched and controlled.
According to such a configuration, by performing switching control of a plurality of load machines connected to the heat pump simultaneously or individually, for example, when the load machine is an air-conditioning indoor unit, cooling or heating in a plurality of rooms By selecting either centralized control or individual control for each room, energy-saving operation such as individual remote start / stop and schedule operation can be performed.
A multi-system building system is generally used as an individual distributed air conditioning system composed of such a heat pump and a plurality of air conditioning indoor units, and a connection between the heat pump and the plurality of air conditioning indoor units is used. Since construction work and control wiring work are standardized, the construction cost can be further reduced by using this multi-standard construction system for buildings.

The ground heat utilization apparatus according to claim 9 is the ground heat utilization apparatus according to any one of claims 1 to 8, wherein the ground heat exchangers are parallel and / or in series with each other. One or a plurality of the heat pumps are connected to the primary piping of one system that is connected in a plurality and connected to the plurality of underground heat exchangers.
According to such a configuration, according to the load required on the load machine side (secondary side), the operation and stop of the plurality of heat pumps can be switched, and the operation efficiency of the entire apparatus is further improved. be able to.

Furthermore, the ground heat utilization apparatus according to claim 10 is the ground heat utilization apparatus according to claim 9, wherein a plurality of systems of the primary side pipes connected to the plurality of underground heat exchangers are provided. The refrigerant is configured to be controllable for circulation and stop of the refrigerant for each system of the plurality of primary side pipes.
According to such a configuration, switching between circulation and stop of a plurality of primary-side piping systems according to the load enables optimization by reducing the refrigerant conveyance power, and improves the operation efficiency of the entire apparatus. It is possible to reduce the burden on the ground where heat is collected and stabilize the underground temperature.

Hereinafter, each embodiment of the present invention will be described with reference to the drawings.
In the second and subsequent embodiments, the same constituent members as those described in the first embodiment and the constituent members having the same functions are denoted by the same reference numerals as those in the first embodiment. Those descriptions are omitted or simplified.

[First Embodiment]
FIG. 1 is a schematic configuration diagram showing an air conditioning apparatus 1 as a geothermal heat utilization apparatus according to a first embodiment of the present invention.
In FIG. 1, an air conditioner 1 includes an underground heat exchanger 2 embedded in the ground G, a heat pump 3 connected to the underground heat exchanger 2, and a load machine connected to the heat pump 3. An air conditioning indoor unit 4, a primary refrigerant pipe (primary side pipe) 5 for connecting a ground heat exchanger 2 and a heat pump 3 to circulate a natural refrigerant such as CO _2, and the heat pump 3 and the air conditioning indoor unit 4. And a secondary refrigerant pipe (secondary pipe) 6 that connects and circulates the refrigerant.
The air conditioner 1 uses the underground heat collected (or radiated) from the underground heat exchanger 2 via the natural refrigerant in the primary refrigerant pipe 5, and the heat pump 3 uses the underground heat in the secondary refrigerant pipe 6. The refrigerant is heated (or cooled), and the air-conditioning indoor unit 4 supplies heat to the air-conditioned space A (or absorbs heat from the air-conditioned space A) through this refrigerant to adjust the room temperature of the air-conditioned space A. .

The heat pump 3 uses the compressor 7 that compresses the refrigerant in the secondary refrigerant pipe 6, the expansion valve 8 that expands the refrigerant in the secondary refrigerant pipe 6, and the natural refrigerant in the primary refrigerant pipe 5 to use the secondary refrigerant. A primary condenser / evaporator (heat exchanger) 9 for condensing or evaporating the refrigerant in the refrigerant pipe 6 is provided.
The air conditioning indoor unit 4 is provided with a secondary condenser / evaporator 10 that condenses the high-temperature refrigerant compressed by the compressor 7 of the heat pump 3 or evaporates the low-temperature refrigerant expanded by the expansion valve 8 of the heat pump 3. It has been.

  The primary refrigerant pipe 5 is bifurcated at the outlet extending from the heat pump 3 toward the underground heat exchanger 2 and at the inlet position to the heat pump 3, and one of the branched pipes is a heat radiating pipe 5A. Is the heat collecting pipe 5B. These heat radiating pipes 5A and heat collecting pipes 5B are each provided with a switching valve 11 in the vicinity of the branching position. The heat radiating pipes 5A for cooling and the heat collecting pipes 5B for heating are switched. The refrigerant is configured to be circulated. Further, the natural refrigerant is sealed in the heat radiation pipe 5A and the heat collecting pipe 5B at different sealed pressures, respectively, and the sealed pressure in the heat collecting pipe 5B is set lower than the sealed pressure in the heat radiation pipe 5A. The sealing pressure is set to a pressure suitable for causing a natural refrigerant to change in a state of vaporization to liquefaction. For example, in the heat radiating pipe 5A, a sealing pressure causing a state change of 30 ° C. to 25 ° C. during cooling. Is set to about 7 MPa, and in the heat collecting pipe 5B, the sealed pressure that causes a state change of 0 ° C. to 5 ° C. during heating is set to about 3.5 MPa.

  In addition, a circulation pump 12 for circulating the natural refrigerant is provided in the heat radiation pipe 5A. On the other hand, the heat collection pipe 5B is not provided with a pump or the like for circulating the natural refrigerant. That is, during the heating operation in winter, in the heat collecting pipe 5B, the natural refrigerant deprived of heat by the primary condenser / evaporator 9 of the heat pump 3 condenses (liquefies), increases its specific gravity, and falls by gravity. It descends in the underground heat exchanger 2 and the natural refrigerant collected from the ground by the underground heat exchanger 2 evaporates (vaporizes) to reduce its specific gravity, and this buoyancy lifts the underground heat exchanger 2 It is supposed to do. By such natural circulation utilizing the state change of the natural refrigerant, a circulation device such as a pump can be dispensed with in the heat collecting pipe 5B.

In the air conditioning apparatus 1 described above, during the cooling operation in summer, the switching valve 11 on the heat radiating pipe 5A side is opened, and the switching valve 11 on the heat collecting pipe 5B side is closed.
The circulation pump 12 sends the natural refrigerant in the heat radiating pipe 5 </ b> A from the primary condenser / evaporator 9 of the heat pump 3 to the underground heat exchanger 2, and in the ground by heat exchange in the underground heat exchanger 2. The natural refrigerant which has been radiated and lowered in temperature is returned to the primary condenser / evaporator 9.
In the heat pump 3, as indicated by arrows in FIG. 1, the primary condenser / evaporator 9 generates heat between the refrigerant in the secondary refrigerant pipe 6 compressed by the compressor 7 and the natural refrigerant in the primary refrigerant pipe 5. Exchange is performed and the refrigerant in the secondary refrigerant pipe 6 is condensed. The refrigerant in the secondary refrigerant pipe 6 that has been condensed and cooled is expanded by the expansion valve 8 and then sent to the air conditioning indoor unit 4 through the secondary refrigerant pipe 6.
In the air conditioning indoor unit 4, the secondary condenser / evaporator 10 performs heat exchange between the refrigerant sent from the expansion valve 8 and the inside air of the air conditioned space A, cools the inside air, and refrigerant in the secondary refrigerant pipe 6. Evaporate. The refrigerant whose temperature is increased by evaporation is compressed again by the compressor 7 and sent to the primary condenser / evaporator 9, and heat exchange is performed with the natural refrigerant in the primary refrigerant pipe 5.
By repeating the cycle as described above, the heat of the air-conditioned space A is discharged into the ground via the refrigerant in the primary and secondary refrigerant pipes 5 and 6, and the air-conditioned space A is cooled.

On the other hand, during the heating operation in winter, the switching valve 11 on the heat radiating pipe 5A side is closed, and the switching valve 11 on the heat collecting pipe 5B side is opened.
Then, as described above, the natural refrigerant in the heat collecting pipe 5B is heated and vaporized by the underground heat exchanger 2, and is cooled and liquefied by the primary condenser / evaporator 9, so that the heat pump 3 Natural circulation between the primary condenser / evaporator 9 and the underground heat exchanger 2.
In the heat pump 3, the refrigerant in the secondary refrigerant pipe 6 is circulated in the direction of the arrow shown in parentheses in FIG. 1, and the primary condenser / evaporator 9 includes the refrigerant expanded in the expansion valve 8 and the primary refrigerant pipe 5. Heat exchange is performed with the natural refrigerant to evaporate the refrigerant in the secondary refrigerant pipe 6. The evaporated and heated refrigerant is compressed by the compressor 7 and then sent to the air conditioning indoor unit 4 through the secondary refrigerant pipe 6.
In the air conditioning indoor unit 4, the secondary condenser / evaporator 10 exchanges heat between the refrigerant in the secondary refrigerant pipe 6 sent from the compressor 7 and the inside air of the air-conditioned space A, and heats the inside air to produce a refrigerant. To condense. The condensed and cooled refrigerant in the secondary refrigerant pipe 6 is expanded again by the expansion valve 8 and sent to the primary condenser / evaporator 9 to exchange heat with the natural refrigerant in the primary refrigerant pipe 5. .
By repeating the above cycle, the heat collected from the ground is supplied to the air-conditioned space A through the refrigerant in the primary and secondary refrigerant pipes 5 and 6, and the air-conditioned space A is heated. .

According to this embodiment, there are the following effects.
(1) That is, the underground heat exchanger 2 and the heat pump 3 are connected by the primary refrigerant pipe 5, and the natural refrigerant in the primary refrigerant pipe 5 is heated to the air conditioning indoor unit 4 side through the primary condenser / evaporator 9. Or a heat transfer system that absorbs heat from the air-conditioning indoor unit 4 side with natural refrigerant in the primary refrigerant pipe 5, compared with the case where the heat transfer water is circulated with a circulation pump on the primary side. The large energy required for circulation can be reduced, and the energy efficiency of the entire air conditioning apparatus 1 can be sufficiently increased.

(2) Further, since the heat pump 3 and the air conditioning indoor unit 4 are connected by the secondary refrigerant pipe 6 and the secondary condenser / evaporator 10 is provided in the air conditioning indoor unit 4, the primary condenser / evaporator 9 uses the primary refrigerant pipe. The refrigerant in the secondary refrigerant pipe 6 that has absorbed heat from the natural refrigerant in the refrigerant 5 (or dissipated heat to the refrigerant in the natural refrigerant in the primary refrigerant pipe 5) passes through the compressor 7 or the expansion valve 8 to the air conditioning indoor unit. Therefore, the secondary circulation pump is unnecessary. In addition, since the refrigerant is directly circulated from the primary condenser / evaporator 9 of the heat pump 3 to the secondary condenser / evaporator 10 of the air conditioning indoor unit 4, loss due to heat exchange can be minimized. Accordingly, the thermal efficiency can be further improved and the driving energy of the secondary circulation pump can be omitted, so that the energy efficiency of the entire air conditioning device 1 can be further increased.

(3) Furthermore, the underground heat exchanger 2 and the heat pump 3 are connected by the primary refrigerant pipe 5, and the heat pump 3 and the air conditioning indoor unit 4 are connected by the secondary refrigerant pipe 6. It is possible to eliminate the restriction when connected by water piping, to improve the workability of the piping, and to reduce the construction cost.

(4) Further, the primary refrigerant pipe 5 is composed of a heat radiating pipe 5A and a heat collecting pipe 5B, and a natural refrigerant is sealed in each of the pipes 5A and 5B at a predetermined pressure suitable for heat radiation or heat collecting. Thus, the heat radiation efficiency to the ground or the heat collection efficiency from the ground in the underground heat exchanger 2 can be increased. Furthermore, by adjusting the refrigerant sealing pressure in the heat collecting pipe 5B so that the natural refrigerant circulates naturally, the circulation pump and the like of the heat collecting pipe 5B can be omitted, and it is necessary for the circulation of the refrigerant. Energy can be further reduced to further improve energy efficiency.

[Second Embodiment]
Next, an air conditioning apparatus 1A as a geothermal heat utilization apparatus according to a second embodiment of the present invention will be described based on FIG.
FIG. 2 is a schematic configuration diagram showing the air conditioning apparatus 1A of the present embodiment.
The air conditioner 1A includes a ground heat exchanger 2, a heat pump 3, an air conditioning indoor unit 4, and a secondary refrigerant pipe 6 similar to the air conditioner 1 of the first embodiment. The configuration of the pipe 5 is different from that of the first embodiment.

  That is, the primary refrigerant pipe 5 is provided with a pressure adjusting device 13 as pressure adjusting means for adjusting the pressure of the natural refrigerant in the primary refrigerant pipe 5, and a bypass path 5 </ b> C is provided across the circulation pump 12. . And the switching valve 11 is provided in the middle position of the detour path 5C, and the position near the circulation pump 12 of the branch part of the detour path 5C. In such a primary refrigerant pipe 5, during the cooling operation (during heat dissipation), the switching valve 11 in the middle of the bypass path 5 </ b> C is closed, the switching valve 11 on the circulation pump 12 side is opened, and the primary pressure regulator 13 performs The natural refrigerant filling pressure in the refrigerant pipe 5 is increased (that is, adjusted to about 7 MPa suitable for heat dissipation as described above), and the natural refrigerant is circulated by the circulation pump 12. On the other hand, at the time of heating operation (at the time of heat collection), the switching valve 11 in the middle of the bypass path 5C is opened, the switching valve 11 on the circulation pump 12 side is closed, and the natural pressure in the primary refrigerant pipe 5 is The cooling pressure of the refrigerant is reduced (that is, adjusted to a charging pressure of about 3.5 MPa suitable for heat collection as described above), and the natural refrigerant is circulated by natural circulation due to a state change.

According to this embodiment, in addition to the effects (1) to (3) described above, the following effects can be obtained.
(5) That is, at the time of heat radiation or heat collection, the pressure regulator 13 adjusts the pressure of the natural refrigerant in the primary refrigerant pipe 5 to a pressure suitable for heat radiation or heat collection. The heat radiation efficiency to the ground or the heat collection efficiency from the ground can be increased. Further, since the natural refrigerant in the primary refrigerant pipe 5 is naturally circulated at the time of heat collection, the operation of the circulation pump 12 can be stopped, and energy required for the circulation of the refrigerant can be further reduced to improve energy efficiency. This can be further improved.
Furthermore, by combining the heat collecting pipe and the heat radiating pipe with different sealing pressures, the initial cost can be reduced, and the pipe installation and laying space in the underground heat exchanger 2 and the primary refrigerant pipe 5 can be reduced. Can do.

[Third Embodiment]
Next, an air conditioning apparatus 1B as a geothermal heat utilization apparatus according to a second embodiment of the present invention will be described based on FIG.
FIG. 3 is a schematic configuration diagram showing the air conditioning apparatus 1B of the present embodiment.
The air conditioner 1B includes a ground heat exchanger 2, a heat pump 3, and a primary refrigerant pipe 5 similar to the air conditioner 1 of the first embodiment, and the heat pump 3 includes a plurality of air conditioning indoor units. 4 is different from the first embodiment in that the plurality of air conditioning indoor units 4 are configured to be capable of switching control of operation and stop at the same time or for each of the plurality of air conditioning indoor units 4. In addition, in the air conditioning apparatus 1B of this embodiment, you may comprise the primary refrigerant | coolant piping 5 similarly to the said 2nd Embodiment.

The plurality of air conditioning indoor units 4 are respectively provided in independent air conditioned spaces A such as a plurality of living rooms provided in a building, and are connected in parallel to one heat pump 3 via a secondary refrigerant pipe 6. And the control communication wiring 14 is connected between the heat pump 3 and the air-conditioning indoor unit 4 of each air-conditioned space A, and the heat pump 3 and each air-conditioning indoor unit 4 operate | move in response to each other. Yes.
A central control device (control panel) 15 is provided in a building management room, a control room, and the like, and the central control device 15 and each air conditioning indoor unit 4 are connected by a central control wiring 16. Furthermore, in each air-conditioned space A, the air-conditioning indoor unit 4 is provided with an individual control device 17 such as a remote controller.

In the air conditioner 1B described above, the heat of each air-conditioned space A is exhausted to the ground via the refrigerant in the primary and secondary refrigerant pipes 5 and 6 as in the air conditioner 1 of the first embodiment. It is configured to heat by cooling or supplying heat from the ground to each air-conditioned space A.
And according to the instruction | command from the centralized control apparatus 15, the driving | operation of the air-conditioning indoor unit 4 of each air-conditioning space A is switched by remote operation. As this remote operation, the air-conditioned indoor units 4 in all the air-conditioned spaces A may be operated or stopped all at once, or the air-conditioned indoor units 4 in each air-conditioned space A may be individually operated or stopped. Further, the air-conditioned indoor unit 4 in each air-conditioned space A may be configured to operate according to the operation schedule set in the centralized control device 15. Further, in addition to the operation control by the central control device 15, the air conditioning indoor unit 4 is configured to be operable by the individual control device 17 of each air conditioning space A.

According to the present embodiment, the following effects are obtained in addition to the effects (1) to (5) described above.
(6) In other words, since cooling and heating in a plurality of air-conditioned spaces A can be centrally controlled, or individually controlled for each air-conditioned space A, energy-saving operations such as centralized or individual remote start / stop and schedule operation are implemented. it can.

(7) In addition, a multi-building construction system for buildings standardized as an individual distributed air conditioning system can be used for connection work between the heat pump 3 and the air conditioning indoor unit 4 in each air conditioning space A, control wiring work, etc. Therefore, the construction cost can be further reduced.

[Fourth Embodiment]
Next, an air conditioning apparatus 1C as a geothermal heat utilization apparatus according to a fourth embodiment of the present invention will be described based on FIG.
FIG. 4 is a schematic configuration diagram showing the air conditioning apparatus 1C of the present embodiment.
The air conditioner 1C of the present embodiment includes a configuration of the primary refrigerant pipe 5, a plurality of underground heat exchangers 2 connected in parallel to each other, and a condensation for atmospheric heat dissipation for recovering the ground temperature in the primary refrigerant pipe 5. The point to which the vessel 18 is connected is different from the air conditioner 1B of the third embodiment, and other configurations are substantially the same as those of the third embodiment. Here, although the thing which connected the some underground heat exchanger 2 in parallel is demonstrated, the some underground heat exchanger 2 may mutually be connected in series. In addition, a plurality of underground heat exchangers 2 may be connected to a plurality of heat pumps 3, and a plurality of systems connected to the plurality of underground heat exchangers 2 may be provided.

  In the air conditioner 1 </ b> C, a plurality of underground heat exchangers 2 are connected to each other in parallel by primary refrigerant pipes 5. As these several underground heat exchangers 2, what was built in the steel pipe pile which is a foundation pile of a building is suitable. The primary refrigerant pipe 5 is connected to the heat pump 3 so as to be switchable with an atmospheric heat radiation condenser 18 for recovering the ground temperature. The atmospheric heat radiation condenser 18 includes a heat exchanger 18A and a fan 18B, and is used to cool the natural refrigerant by exchanging heat between the natural refrigerant in the primary refrigerant pipe 5 and the outside air. In other words, when the amount of heat released from the underground heat exchanger 2 to the ground G during the cooling operation in summer is too large to balance the amount of heat collected during the heating operation in winter, including the natural resilience of the ground G Radiates and releases excess heat from the ground G from the atmospheric heat radiation condenser 18 to the atmosphere, recovers the underground temperature, and enables the use of underground heat for a long time.

  And the structure of the primary refrigerant | coolant piping 5 is as substantially the same as the said 2nd Embodiment, and while a circulation path is switched by the some switching valve 11 at the time of heat radiation and heat collection, a primary refrigerant | coolant is not shown by the pressure regulator which is not shown in figure. The sealed pressure of the natural refrigerant in the pipe 5 is adjusted. Moreover, in the primary refrigerant | coolant piping 5, the liquid receiver 19 is provided in the position before the circulation pump 12 in the circulation path at the time of heat radiation. During the cooling operation (at the time of heat dissipation), the liquid receiver 19 is supplied to the circulation pump 12 even if a part of the natural refrigerant condensed in the underground heat exchanger 2 returns without being liquefied but mixed with gas. In order to prevent air from being caught, the liquid natural refrigerant separated from the gas and liquid by the liquid receiver 19 is sent to the circulation pump 12. On the other hand, at the time of heat collection, since the natural refrigerant is circulated by the natural circulation due to the state change as described above, the operation of the circulation pump 12 becomes unnecessary.

According to the present embodiment, the following effects are obtained in addition to the effects (1) to (3) and (5) to (7) described above.
(8) That is, when the cooling load in the summer is larger than the heating load in the winter, the ground temperature rises by dissipating excess heat in the ground from the atmospheric heat radiation condenser 18 to the atmosphere. Can be prevented, and heat can be collected on a stable ground for a long period of time.

(9) In addition, the plurality of underground heat exchangers 2 are operated by appropriately switching according to the load, or a plurality of systems to which the plurality of underground heat exchangers 2 are connected are provided, and the plurality of systems are appropriately switched for operation. As a result, it is possible to further improve the operation efficiency of the entire air conditioner 1C while suppressing the burden on the ground G.

Note that the present invention is not limited to the above-described embodiments, and includes other configurations that can achieve the object of the present invention, and includes the following modifications and the like.
For example, in each of the above-described embodiments, the air conditioners 1, 1A, 1B, and 1C have been described. However, the geothermal heat utilization apparatus of the present invention is not limited to an air conditioner that can be cooled and heated, and is capable of cooling only. It may be a device or a heating device capable of heating only, or may be a refrigerator (freezer), a warmer, a water heater, a water heater, or the like.

Moreover, in each said embodiment, the system which connects between the primary condenser / evaporator 9 of the heat pump 3 and the secondary condenser / evaporator 10 of the air-conditioning indoor unit 4 with the secondary refrigerant | coolant piping 6 directly circulates a refrigerant | coolant. However, the secondary side pipe may be a water pipe that circulates heat transfer water such as water or antifreeze. In this case, the secondary condenser / evaporator 10 is provided in the heat pump 3, What is necessary is just to provide the refrigerant | coolant piping which circulates a refrigerant | coolant between the primary and secondary condenser / evaporators 9,10, the compressor 7, and the expansion valve 8. FIG.
Moreover, in the said 1st-3rd embodiment, although the description of the liquid receiver 19 in the said 4th Embodiment was abbreviate | omitted, the same liquid receiver is provided also in the primary refrigerant | coolant piping 5 of the 1st-3rd embodiment. Thus, the air pumping of the circulation pump 12 can be prevented.

  In the fourth embodiment, the atmospheric heat radiation condenser 18 is connected to the primary refrigerant pipe 5. However, the present invention is not limited to this, and an atmospheric heat recovery evaporator for ground temperature recovery may be connected. The condenser for air and the evaporator for atmospheric heat collection may be connected in parallel and switchable. If such an atmospheric heat collecting evaporator is connected, when the heating load in the winter season becomes excessively higher than the cooling load, the connection of the primary side pipe from the underground heat exchanger is connected to the atmospheric heat collecting evaporator. By switching to the side and supplying the heat collected from the atmosphere to the ground, it is possible to prevent a decrease in underground temperature and perform heat collection from the stable ground over a long period of time.

In addition, the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described with particular reference to certain specific embodiments, but without departing from the spirit and scope of the invention, Various modifications can be made by those skilled in the art in terms of material, quantity, and other detailed configurations.
Therefore, the description limiting the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

It is a schematic structure figure showing the underground heat utilization apparatus concerning a 1st embodiment of the present invention. It is a schematic block diagram which shows the underground heat utilization apparatus which concerns on 2nd Embodiment of this invention. It is a schematic block diagram which shows the underground heat utilization apparatus which concerns on 3rd Embodiment of this invention. It is a schematic block diagram which shows the underground heat utilization apparatus which concerns on 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Ground heat exchanger, 3 ... Heat pump, 4 ... Air-conditioning indoor unit as a load machine, 5 ... Primary refrigerant | coolant piping as primary side piping, 5A ... Radiation piping, 5B ... Heat collection piping, 6 ... Secondary Secondary refrigerant pipe as side pipe, 7 ... compressor, 8 ... expansion valve, 9 ... primary condenser / evaporator (heat exchanger), 10 ... secondary condenser / evaporator, 13 ... pressure regulation as pressure regulating means Apparatus, 18 ... Condenser for atmospheric heat radiation.

Claims (10)

A ground heat exchanger buried in the ground, a heat pump connected to the ground heat exchanger, a load machine connected to the heat pump, and a primary connecting the ground heat exchanger and the heat pump. Side piping,
The primary side pipe is a refrigerant pipe for circulating the refrigerant,
The heat pump is provided with a heat exchanger that exchanges heat with the refrigerant in the primary side pipe, and supplies heat to the load machine or absorbs heat from the load machine through the heat exchanger. A geothermal heat utilization device characterized by that. In the geothermal heat utilization apparatus according to claim 1,
The refrigerant in the primary side pipe is naturally circulated due to a change in specific gravity due to gasification and liquefaction of the refrigerant at the time of heat collection from the underground heat exchanger. In the geothermal heat utilization apparatus according to claim 1 or claim 2,
The primary side pipe is branched into a heat radiating pipe and a heat collecting pipe, and the heat radiating pipe and the heat collecting pipe are switchable.
The refrigerant is sealed at a predetermined pressure in the heat radiation pipe,
The underground heat utilization device, wherein the refrigerant is sealed in the heat collecting pipe at a pressure lower than that of the refrigerant in the heat radiating pipe. In the geothermal heat utilization apparatus according to claim 1 or claim 2,
The primary side pipe is provided with a pressure adjusting means for adjusting the pressure of the refrigerant in the primary side pipe. By this pressure adjusting means, the pressure of the refrigerant in the primary side pipe at the time of heat collection is higher than that during heat dissipation. A ground heat utilization device characterized by being adjusted low. In the underground heat utilization apparatus in any one of Claims 1-4,
A geothermal heat utilization apparatus, wherein the refrigerant in the primary side pipe is a carbon dioxide refrigerant. In the underground heat utilization apparatus in any one of Claims 1-5,
The primary side pipe is connected to the heat pump so that an atmospheric heat radiation condenser and / or an atmospheric heat collection evaporator can be switched to the heat pump.
The atmospheric heat radiation condenser radiates excess heat stored in the ground due to heat radiation from the underground heat exchanger to the atmosphere, and the atmospheric heat collection evaporator collects heat from the underground heat exchanger. A ground heat utilization device that supplies heat collected from the atmosphere to the ground whose temperature has been lowered by the above. In the underground heat utilization apparatus in any one of Claims 1-6,
The heat pump and the load machine are connected by a secondary side pipe constituted by a refrigerant pipe for circulating the refrigerant,
The heat pump is provided with a compressor for compressing the refrigerant in the secondary side pipe and an expansion valve for expanding the refrigerant in the secondary side pipe, and the heat exchanger is provided in the primary side pipe. A primary condenser / evaporator for condensing or evaporating the refrigerant in the secondary pipe using the refrigerant;
The load machine condenses the refrigerant in the high-temperature secondary pipe compressed by the compressor of the heat pump, or the refrigerant in the low-temperature secondary pipe expanded by the expansion valve of the heat pump. A geothermal heat utilization device, characterized in that a secondary condenser / evaporator for evaporation is provided. In the geothermal heat utilization apparatus according to claim 7,
A plurality of the load machines are connected to the heat pump, and the geothermal heat is configured such that operation and stop of the plurality of load machines can be switched at the same time or for each of the plurality of load machines. Use device. In the underground heat utilization apparatus in any one of Claims 1-8,
A plurality of the underground heat exchangers are connected in parallel and / or in series with each other, and one or a plurality of the heat pumps are connected to one system of the primary side pipes connected to the plurality of underground heat exchangers. A geothermal heat utilization device characterized by that. The geothermal heat utilization apparatus according to claim 9,
A plurality of systems of the primary side pipes connected to the plurality of underground heat exchangers are provided, and the circulation and stop of the refrigerant are configured to be switchable for each system of the plurality of primary side pipes. A geothermal heat utilization device.

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