JP2006292310A - Geothermal heat pump device, geothermal unit having it, and control method of geothermal heat pump device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a geothermal heat pump device stably operable over a long time adaptedly to a thermal situation of the ground, and to provide its control method. <P>SOLUTION: A limit value of heat collection and heat radiation is set based on the outlet temperature of heat medium water from a heat pump 3 to an underground heat exchanger 2 measured with a temperature sensor 14, and the operation of the heat pump 3 is controlled not to exceed the set limit value of the heat collection and heat radiation. Thus, the underground temperature can be prevented from becoming too high (or low) to extremely decrease the heat collection/radiation efficiency during the operation of an air conditioner, the underground temperature can be prevented from gradually increasing (or decreasing) over a long time and disabling the heat collection/radiation, and hence stable operation can be achieved over a long time adaptedly to the thermal situation of the ground 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a geothermal heat pump device, a geothermal heat device provided with the same, and a control method for the geothermal heat pump device, and more specifically, connected to a geothermal heat exchanger embedded in the ground. A heat pump that uses a geothermal heat that collects heat from the ground or dissipates heat to the ground via a geothermal heat exchanger, a geothermal heat utilization device that includes the heat pump, and a control of the geothermal heat pump device The present invention relates to a method apparatus.

An underground heat exchanger buried in the ground, a heat pump body connected to the underground heat exchanger, and a secondary side (load side) heat exchanger such as an air conditioner connected to the heat pump body A geothermal heat utilization device provided is known (for example, see Patent Document 1).
An air conditioner or the like equipped with such a heat pump that uses geothermal heat uses the ground heat of the ground having a stable temperature as a heat source, and collects and dissipates heat from this heat source. Compared to a system of air heat source system that dissipates heat, 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.

JP 2003-302122 A

However, in the conventional geothermal heat utilization apparatus as described in Patent Document 1, the operation is only performed following the load on the secondary side, and the operation is controlled according to the thermal condition of the ground. Therefore, there is a possibility that continuous operation over a long period of time becomes difficult, which is a problem.
That is, when the load on the secondary side (for example, a cooling load or a heating load) is operated exceeding the planned value, the underground temperature becomes a high temperature or a low temperature exceeding the allowable value at which the heat pump can be operated efficiently. It may end up. Also, if the load on the secondary side becomes large and the heat is dissipated too much into the ground or if too much heat is taken from the ground, the underground temperature throughout the year will gradually increase or decrease. After a few years, the heat-dissipating efficiency may be significantly reduced, or heat dissipation may be impossible or heat extraction may not be possible. Furthermore, if the ground thermal conductivity changes due to fluctuations in groundwater level or groundwater flow conditions, etc., and the heat collection and heat radiation capacity at the initial stage of the plan have fallen, it is sufficient for load treatment. There is a possibility that it will be impossible to carry out heat radiation.

  An object of the present invention is to provide a geothermal heat pump device that can adapt to the thermal condition of the ground and realize stable operation over a long period of time, a geothermal heat utilization device including the same, and a geothermal heat utilization heat pump device. It is to provide a control method.

  The ground heat utilization heat pump device of the present invention connects a ground heat exchanger embedded in the ground, a heat pump body connected to the ground heat exchanger, and the ground heat exchanger and the heat pump. A heat pump device that circulates heat transfer water and uses the underground heat exchanger to collect heat from the ground or radiate heat to the ground, and measures the thermal condition of the ground Measuring means to perform, limit value setting means for setting the limit value of heat extraction / radiation based on the measured thermal condition of the ground, and operation control for controlling the operation of the heat pump body so as not to exceed the set limit value of heat extraction / radiation Means.

Here, the thermal condition of the ground measured by the measuring means includes the initial ground temperature, the ground temperature during the operation period, the thermal characteristics of the ground such as the thermal conductivity of the ground, the groundwater level and the groundwater flow status, etc. Examples include information that affects thermal characteristics. Of these, the ground temperature may be directly measured by a temperature sensor or the like provided in the ground, the temperature of the heat transfer water circulated between the underground heat exchanger and the heat pump body, the surface temperature of the piping, etc. The temperature estimated from
In addition, the heat collection / dissipation limit value set by the limit value setting means includes not only the heat collection / discharging amount that can be borne by the ground near the installation position where the heat pump device is installed, but also heat transfer from the surrounding ground and groundwater. It is set based on the burden heat radiation amount in consideration of the heat carried by the flow. In other words, the limit value of heat extraction is set based on analysis that takes into account the natural recovery of the ground when it is viewed over the long term in a few years to a decade. .

  According to the present invention described above, the limit value of heat extraction / radiation is set based on the thermal condition of the ground measured by the measuring means, and the operation of the heat pump body is controlled so as not to exceed the set limit value of heat extraction / radiation. During operation, the underground temperature becomes too high (or low) and the heat extraction efficiency decreases significantly, or the underground temperature gradually rises (or decreases) over the long term, making it impossible to extract heat. Can be prevented, and stable operation can be realized over a long period of time by adapting to the thermal condition of the ground. At this time, if the limit value setting means is configured to set the limit value of heat extraction / radiation in consideration of the thermal natural recovery factor of the ground, the limit value of heat extraction / radiation will not be set too low. The device can be designed and the installation cost can be reduced.

The geothermal heat pump device according to claim 2 is the geothermal heat pump device according to claim 1, wherein the limit value setting means is the previous year or several years before measured by the measurement means. It is configured to reset the limit value based on the thermal condition of the ground.
According to such a configuration, it is possible to set a more reasonable limit value according to changes in the ground condition by resetting the limit value of heat extraction and heat dissipation considering the thermal condition of the past ground during the operation period. It becomes possible to improve the operation efficiency of the apparatus or reduce the burden on the ground. That is, if the natural recovery ability of the ground is higher than originally assumed, it may be reset so as to increase the limit value of heat extraction, and in this way, the operation efficiency of the apparatus can be increased. On the other hand, if the natural recovery ability of the ground is lower than originally assumed, resetting to lower the heat dissipation limit value will prevent excessive or long-term fluctuations in the underground temperature, and ground sampling. Heat dissipation capability can be maintained.

Furthermore, the underground heat utilization heat pump device according to claim 3 is the underground heat utilization heat pump device according to claim 1 or 2, wherein the measuring means is an outlet from the heat pump main body in the pipe or the It has the temperature sensor which measures the temperature of the said heat-medium water of the inlet_port | entrance position to a heat pump main body, It is characterized by the above-mentioned.
According to such a configuration, the ground temperature can be estimated from the measured outlet temperature or inlet temperature by measuring the temperature of the heat transfer water using the temperature sensor at the outlet or inlet position of the heat pump main body. Compared with the case where a temperature sensor is installed in a heat exchanger or the like, the number of locations where the temperature sensor is installed can be reduced, and the initial cost and the cost required for maintenance can be suppressed.

Moreover, the underground heat utilization heat pump apparatus of Claim 4 WHEREIN: The underground heat utilization heat pump apparatus in any one of Claims 1-3 WHEREIN: The said underground heat exchanger is provided in the said heat pump main body. When a different auxiliary heat source is connected and the heat extraction / radiation in the underground heat exchanger reaches the set limit value, the heat pump body is controlled by the operation control means so as to use the auxiliary heat source. It is characterized by being.
Here, examples of the auxiliary heat source include a cooling tower, an air heat exchanger, an exhaust heat recovery device, and the like that collect and dissipate heat using air as a heat source.
According to such a configuration, the auxiliary heat source is connected to the heat pump main body, and the auxiliary heat source is used when the heat radiation of the underground heat exchanger reaches the limit value, so the load on the secondary side becomes large. Even if the heat radiation from the underground heat exchanger is stopped, the operation of the heat pump main body can be continued using the heat from the auxiliary heat source. Therefore, for example, when the secondary side is an air-conditioning indoor unit, the cooling operation and the heating operation can be continued without imposing an excessive burden on the ground even in the summer and winter when the load increases.

On the other hand, a geothermal heat utilization device of the present invention includes a ground heat utilization heat pump device according to any one of claims 1 to 4, and a load machine connected to a heat pump body of the geothermal heat utilization heat pump device. The heat load device is connected to another heat source device that is different from the heat pump main body, and the heat extraction / radiation in the ground heat exchanger reaches the set limit value. In this case, heat is supplied to or absorbed from the load machine using the other heat source device.
Here, the load machine is supplied from the heat pump main body (or absorbed by the heat pump main body) such as an air conditioner indoor unit that performs indoor cooling, heating, or air conditioning, a refrigeration (refrigeration) warmer, a water heater, or a water heater. And various types of equipment using heat.
Moreover, as another heat source apparatus different from the heat pump main body, a refrigerator, a boiler, a cold / hot water generator etc. can be illustrated.

  According to the present invention as described above, when another heat source device is connected to the load machine, and the heat radiation from the underground heat exchanger reaches a limit value, heat is supplied to the load machine using the other heat source device. Or since heat is absorbed from the load machine, even if the load on the secondary side becomes large and heat dissipation from the underground heat exchanger is stopped, the operation of the load machine can be continued by other heat source equipment. . Therefore, for example, when the load machine is an air-conditioning indoor unit, the cooling operation and the heating operation can be continued without imposing an excessive burden on the ground even in summer and winter when the load increases.

Further, the control method of the heat pump device using ground heat according to the present invention includes a ground heat exchanger embedded in the ground, a heat pump body connected to the ground heat exchanger, and the ground heat exchanger. A method for controlling a heat pump device using geothermal heat that includes a pipe that connects the heat pump and circulates heat transfer water and collects heat from the ground or radiates heat to the ground via the ground heat exchanger. , A measurement process to measure the thermal condition of the ground, a limit value setting process to set the limit value of heat extraction based on the measured thermal condition of the ground, and a heat pump so as not to exceed the set limit value of heat extraction And an operation control process for controlling the operation of the main body.
According to the present invention described above, as described above, it is possible to realize a stable operation over a long period of time by adapting to the thermal condition of the ground, and it is possible to design a rational heat pump device, thereby reducing the installation cost. Can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an air conditioner 1 as a geothermal heat utilization device according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram illustrating a heat pump device 1 </ b> A that is a main part of the air conditioning device 1.
1 and 2, an air conditioner 1 includes an underground heat exchanger 2 embedded in the ground G, a heat pump (heat pump body) 3 connected to the underground heat exchanger 2, and the heat pump 3. An air conditioner indoor unit 4 as a load machine connected to the water, a water pipe 5 for connecting the underground heat exchanger 2 and the heat pump 3 to circulate heat transfer water such as water or antifreeze liquid, the heat pump 3 and the air conditioner indoor unit 4 and a water pipe 6 that circulates heat transfer water such as water or antifreeze liquid.

The heat pump 3 includes a refrigerant pipe 11 that circulates refrigerant (gas), a compressor 7 that compresses the refrigerant in the refrigerant pipe 11, an expansion valve 8 that expands the refrigerant in the refrigerant pipe 11, and the heat of the water pipe 5. A primary condenser / evaporator 9 that condenses or evaporates the refrigerant using the medium water, and condenses the high-temperature refrigerant compressed by the compressor 7 to supply heat to the heat transfer water in the water pipe 6, or the expansion valve 8 A secondary condenser / evaporator 10 is provided that evaporates the low-temperature refrigerant expanded in step, and absorbs heat from the heat transfer water in the water pipe 6.
The water pipes 5 and 6 are provided with circulation pumps 12 and 13 for circulating the respective heat transfer water.
Then, the heat pump device 1A uses the underground heat collected (or radiated) from the underground heat exchanger 2 via the heat transfer water, and the water pipe 6 passes through the refrigerant in the refrigerant pipe 11 of the heat pump 3. The temperature of the heat transfer water is raised (cooled), and heat is supplied from the air conditioning indoor unit 4 to the air conditioned space A (or heat is absorbed from the air conditioned space A) by the heat transfer water.

That is, in the heat pump device 1A, during the cooling operation in summer, the heat transfer water in the water pipes 5 and 6 and the refrigerant in the refrigerant pipe 11 are circulated in the directions indicated by arrows in FIG.
That is, the circulation pump 12 sends the heat transfer water from the primary condenser / evaporator 9 of the heat pump 3 to the underground heat exchanger 2, and radiates heat to the ground by heat exchange in the underground heat exchanger 2. The lowered heat transfer water is returned to the primary condenser / evaporator 9.
In the heat pump 3, the primary condenser / evaporator 9 performs heat exchange between the refrigerant compressed by the compressor 7 and the heat transfer water in the water pipe 5 to condense the refrigerant. The condensed and cooled refrigerant is expanded by the expansion valve 8 and then sent to the secondary condenser / evaporator 10. The secondary condenser / evaporator 10 exchanges heat between the refrigerant sent from the expansion valve 8 and the heat transfer water in the water pipe 6 to cool the inside air and evaporate the refrigerant. The refrigerant whose temperature has been 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 heat transfer water in the water pipe 5.
The circulation pump 12 sends the heat transfer water in the water pipe 6 cooled by the secondary condenser / evaporator 10 to the air conditioning indoor unit 4 and absorbs heat from the inside air of the air conditioned space A to raise the temperature. The water is returned to the secondary condenser / evaporator 10.
By repeating the cycle as described above, the heat of the air-conditioned space A is discharged into the ground via the refrigerant and the heat transfer water, and the air-conditioned space A is cooled.

On the other hand, during the heating operation in winter, the refrigerant in the refrigerant pipe 11 is circulated in the direction opposite to the arrow in FIG. The circulation direction of the heat transfer water in the water pipes 5 and 6 is as shown by arrows in FIG.
That is, in the heat pump 3, the primary condenser / evaporator 9 performs heat exchange between the refrigerant expanded by the expansion valve 8 and the heat transfer water in the water pipe 5 to evaporate the refrigerant. The refrigerant that has been evaporated and heated is compressed by the compressor 7 and then sent to the secondary condenser / evaporator 10. The secondary condenser / evaporator 10 exchanges heat between the refrigerant sent from the compressor 7 and the heat transfer water in the water pipe 6 to heat the inside air and condense the refrigerant. The condensed and cooled refrigerant is expanded again by the expansion valve 8 and sent to the primary condenser / evaporator 9, and heat exchange is performed with the heat transfer water in the water pipe 5.
By repeating the above cycle, the heat collected from the ground via the refrigerant and the heat transfer water is supplied to the air-conditioned space A, and the air-conditioned space A is heated.

  As shown in FIG. 1, the air conditioner 1 is connected to a single water pipe 5 in which a plurality of underground heat exchangers 2 are connected in parallel to each other, and the plurality of underground heat exchangers 2 are connected. A plurality (two) of heat pumps 3 are connected via the header 5A. The plurality of heat pumps 3 are configured to be capable of switching control of operation and stop at the same time or for each heat pump 3. In addition, water pipes 6 extending from a plurality (two) of heat pumps 3 are gathered through a pipe header 6 </ b> A and connected to the air conditioning indoor unit 4. Note that a plurality of air conditioning indoor units 4 may be connected to the heat pump 3 described above, and the operation and stop of the plurality of air conditioning indoor units 4 can be switched and controlled simultaneously or for each of the plurality of air conditioning indoor units 4. It may be configured.

Furthermore, the air conditioner 1 includes a cooling tower 21 as an auxiliary heat source, and a refrigerator (chiller) 23 and a boiler 30 as other heat source devices.
The cooling tower 21 cools circulating water (heat transfer water) using air as a heat source, and is connected to the pipe header 5A by a water pipe 22 for circulating the circulating water. Is connected to the heat pump 3. That is, when the heat pump 3 is operated at a high load in the summer and the heat extraction / dissipation of the ground G by the underground heat exchanger 2 reaches a limit value as will be described later, the heat transfer water to the underground heat exchanger 2 side is reached. The circulation is stopped or suppressed, and the heat transfer water is circulated to the cooling tower 21 side, whereby the cooling operation of the heat pump 3 is continued.

  The refrigerator 23 is connected to the pipe header 6 </ b> A by a water pipe 24 that circulates heat transfer water in the same manner as the water pipe 6, and similarly to the heat pump 3, a compressor 25, an expansion valve 26, an evaporator 27, and a refrigerant The heating medium water in the water pipe 24 is cooled by heat exchange in the evaporator 27. The water pipe 24 is provided with a circulation pump 29. The circulation pump 29 causes heat transfer water in the water pipe 24 to pass between the air conditioning indoor unit 4 and the evaporator 27 of the refrigerator 23 via the pipe header 6A. Is supposed to be circulated. Such a refrigerator 23 is operated when the heat pump 3 is operated at a high load in summer, and the heat radiation to the ground G by the underground heat exchanger 2 reaches a limit value, and the operation of the heat pump 3 is stopped or suppressed. The cooling operation of the air conditioner indoor unit 4 is continued by the operation of the refrigerator 23.

  The boiler 30 is connected to the pipe header 6A by a water pipe 31 that circulates heat transfer water similarly to the water pipes 6 and 24, and generates heat by burning fossil fuel such as light oil. The temperature is raised. The water pipe 31 is provided with a circulation pump 32, and the heat pump water in the water pipe 31 is circulated between the air conditioning indoor unit 4 and the boiler 30 via the pipe header 6A. It has become so. Such a boiler 30 is operated when the heat pump 3 is operated at a high load in the winter, the heat collection from the ground G by the underground heat exchanger 2 reaches a limit value, and the operation of the heat pump 3 is stopped or suppressed. The heating operation of the air conditioning indoor unit 4 is continued by the operation of the boiler 30.

  As shown in FIG. 2, the heat pump device 1 </ b> A in the air conditioning device 1 as described above is provided at the outlet position of the water pipe 5 from the heat pump 3 to the underground heat exchanger 2 to set the outlet temperature of the heat transfer water. There are provided a temperature sensor 14 as measurement means for measuring, and a control device 15 for determining the thermal condition of the ground G based on the outlet temperature of the heat transfer water measured by the temperature sensor 14. The control device 15 is composed of, for example, a computer, and the ground temperature that is the thermal condition of the ground G from the outlet temperature of the heat transfer water (in the ground heat exchanger 2) according to pre-input data or a built-in program. Surface temperature) is calculated. The control device 15 functions as limit value setting means for setting the limit value of heat extraction / dissipation by the underground heat exchanger 2 based on the calculated underground temperature, and does not exceed the set limit value of heat extraction / discharging. Also, it functions as an operation control means for controlling the operation of the heat pump 3.

  That is, in the air conditioner 1, when the annual load fluctuation as shown by the curve L1 in the graph of FIG. 3 occurs, the annual heat transfer water in which the curve L2 shown by the thin solid line in the graph of FIG. 4 is assumed. The outlet temperature fluctuation curve (reference fluctuation curve) is shown. And the curve L3 shown by the fine dashed-dotted line in the graph of FIG. 4 is a fluctuation curve of the surface temperature of the underground heat exchanger 2 for a year calculated from the outlet temperature of the heat transfer water. Here, the curve L2 ′ (thick solid line in the figure) indicates the outlet temperature of the heat transfer water when the heating load in the winter season becomes excessive and the heat collection from the ground G by the underground heat exchanger 2 becomes excessive. The curve L3 ′ (in the figure, a thick one-dot chain line) shows the curve of the surface temperature of the underground heat exchanger 2 at that time. That is, when the heat collection from the ground G becomes excessive, the underground temperature falls below the previous year's underground temperature, which indicates that the heat collection ability of the ground G is lowered. On the other hand, in the curves L2 and L3, the underground temperature after one year is substantially the same as the previous year, and the heat-dissipating ability of the ground G is maintained. Therefore, the control device 15 sets a limit value for heat extraction based on the fluctuation curve (reference fluctuation curve) L2 of the outlet temperature of the heat transfer water for the year.

  The limit value (limit outlet temperature) of heat extraction / radiation is set as a curve L4 indicated by a one-dot chain line in the graph of FIG. 5, and the heating load period with respect to the variation curve L2 of the outlet temperature of the heat transfer water. The cooling load period is set to be higher by a predetermined temperature than the curve L2 (limit value setting step). At this time, the predetermined temperature, which is a difference from the curve L2, is set based on analysis and experiment considering that the ground G naturally recovers thermally by heat transfer from the surrounding ground. Then, according to the set limit outlet temperature, the heat pump apparatus 1A measured with the temperature sensor 14 as indicated by a curved line L5 in FIG. 5 (measurement step). When reaching L4), the operation of the heat pump 3 is stopped or suppressed by the control device 15. By stopping or suppressing the operation of the heat pump 3 as described above, the operation of the heat pump 3 is resumed by the control device 15 if the outlet temperature of the heat transfer water recovers until reaching the curve L2 (operation control process). By carrying out such operation control of the heat pump 3, the underground temperature can be prevented from being excessively lowered or increased.

  On the other hand, the thermal condition of the ground G is not relatively stable for several years (for example, about 5 years) from the start of operation of the air conditioner 1, and the curve L6 (first year) shown in the graph of FIG. It is lower than the previous year's underground temperature, as shown in the fluctuation curve of the outlet temperature of the heat transfer water, thin solid line) and the curve L7 (the fluctuation curve of the surface temperature of the underground heat exchanger 2 in the first year, fine dotted line). May become (or become expensive). Then, after several years from the start of operation, the curve L6 ′ (fluctuation curve of the outlet temperature of the heat transfer water in the fifth year, thick solid line) and the curve L7 ′ (the underground in the fifth year) shown in the graph of FIG. As shown in the fluctuation curve of the surface temperature of the heat exchanger 2, the thick one-dot chain line), the difference in the underground temperature from the previous year becomes smaller and stable. For this reason, in the heat pump device 1A of the present embodiment, the control device 15 generates the reference fluctuation curve (L6, L6 ′) every year based on the measurement result of the outlet temperature of the heat transfer water of the previous year for several years from the start of operation. The control device 15 sets the limit value of heat extraction / radiation based on the reference fluctuation curve.

According to this embodiment, there are the following effects.
(1) That is, based on the outlet temperature of the heat transfer water from the heat pump 3 to the underground heat exchanger 2 measured by the temperature sensor 14, the limit value (curve L4) of heat extraction / radiation is set, and the set limit of heat extraction / radiation By controlling the operation of the heat pump 3 so as not to exceed the value, the underground temperature becomes too high (or low) during the operation of the air conditioning device 1, and the heat radiation efficiency is significantly reduced, It is possible to prevent the temperature from gradually increasing (or decreasing) and dissipating heat, and adapting to the thermal condition of the ground 3 to achieve stable operation over a long period of time.

(2) Furthermore, since the limit value of heat extraction / radiation is set in consideration of the thermal natural recovery factor of the ground G, the limit value of heat extraction / radiation is not set too low, and a reasonable heat pump device. 1A can be designed, and the installation cost of the air conditioning apparatus 1 can be reduced.

(3) In addition, the reference fluctuation curve (L6, L6 ′) and the limit value of heat extraction are re-set in consideration of the past thermal condition of the ground G during the operation period. A reasonable limit value can be set, and the operating efficiency of the heat pump apparatus 1A can be improved, or the burden on the ground G can be reduced.

(4) Furthermore, since the temperature sensor 14 for measuring the outlet temperature of the heat transfer water from the heat pump 3 to the underground heat exchanger 2 is provided, the underground temperature can be estimated from the measured outlet temperature. Compared with the case where a temperature sensor is installed in the underground heat exchanger 2 or the like, the number of installation locations of the temperature sensor 14 can be reduced, and the initial cost and the cost required for maintenance can be suppressed.

(5) Moreover, since the cooling tower (auxiliary heat source) 21 is connected to the heat pump 3 and the cooling tower 21 is used when the heat radiation of the underground heat exchanger 2 reaches the limit value, the air conditioning load increases. Even if the heat extraction from the underground heat exchanger 2 is stopped or suppressed, the operation of the heat pump 3 can be continued using the heat from the cooling tower 21. Therefore, the cooling operation of the air conditioning indoor unit 4 can be continued without imposing an excessive burden on the ground G.

(6) Furthermore, when the refrigerator 23 and the boiler 30 which are other heat source devices are connected to the air conditioning indoor unit 4 and the heat extraction / radiation of the underground heat exchanger 2 reaches the limit value, the refrigerator 23 and the boiler 30 are connected. Since heat is supplied to the air conditioning indoor unit 4 or absorbed from the air conditioning indoor unit 4, the refrigeration can be performed even if the air conditioning load becomes large and heat radiation from the underground heat exchanger 2 is stopped or suppressed. The operation of the air conditioning indoor unit 4 can be continued by the machine 23 and the boiler 30.

In addition, this invention is not limited to the said embodiment, Including other structures etc. which can achieve the objective of this invention, the deformation | transformation etc. which are shown below are also contained in this invention.
For example, in the above-described embodiment, the air conditioner 1 has been described. However, the geothermal heat utilization apparatus of the present invention is not limited to an air conditioner capable of cooling and heating, and is a cooling apparatus capable of only cooling or heating capable of heating only. An apparatus may be sufficient and a refrigerator (freezer), a warm storage machine, a water heater, a water heater, etc. may be sufficient.

  Moreover, in the said embodiment, although the temperature sensor 14 which measures the exit temperature of the heat transfer water from the heat pump 3 to the underground heat exchanger 2 was used as a measurement means, you may measure an entrance temperature with the temperature sensor 14. The measuring means is not limited to such a temperature sensor 14, but may be a sensor that directly measures the underground temperature of the ground G, a sensor that measures the surface temperature of the underground heat exchanger 2, and the ground G A measuring device that measures the thermal conductivity of the ground may be used, and a device that can measure the thermal characteristics of various grounds is applicable.

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 block diagram which shows the underground heat utilization apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the heat pump apparatus which is the principal part of the said underground heat utilization apparatus. It is a graph which shows the annual load fluctuation | variation in the said geothermal heat utilization apparatus. It is a graph which shows the fluctuation | variation of the exit temperature of the heat-source side heat transfer water in the said heat pump apparatus, and the surface temperature of an underground heat exchanger. It is a graph which shows the operation control method in the said heat pump apparatus. It is a graph which shows the fluctuation | variation of the said exit temperature and the said surface temperature of the 1st year and the 5th year after the operation start in the said heat pump apparatus.

Explanation of symbols

  1A ... heat pump device, 2 ... underground heat exchanger, 3 ... heat pump (heat pump main body), 5 ... water piping, 14 ... temperature sensor (measuring means), 15 ... control device (limit value setting means and operation control means)) , 21 ... Cooling tower (auxiliary heat source), 23 ... Refrigerator (other heat source equipment), 30 ... Boiler (other heat source equipment), G ... Ground.

Claims (6)

An underground heat exchanger embedded in the ground, a heat pump main body connected to the underground heat exchanger, and a pipe for circulating the heat transfer water by connecting the underground heat exchanger and the heat pump. A heat pump device that uses ground heat to collect heat from the ground or dissipate heat to the ground via the ground heat exchanger,
Measuring means to measure the thermal condition of the ground, limit value setting means to set the limit value of heat extraction based on the measured thermal condition of the ground, and the heat pump body so as not to exceed the set limit value of heat extraction An operation control means for controlling the operation of the heat pump apparatus using geothermal heat. In the geothermal heat pump device according to claim 1,
The limit value setting means is configured to reset the limit value based on the thermal condition of the ground for the previous year or the previous several years measured by the measurement means. Heat utilization heat pump device. In the heat pump apparatus using geothermal heat according to claim 1 or claim 2,
The measurement means has a temperature sensor for measuring the temperature of the heat transfer water at the outlet from the heat pump main body or at the inlet position to the heat pump main body in the pipe. . In the geothermal heat utilization heat pump device according to any one of claims 1 to 3,
An auxiliary heat source different from the underground heat exchanger is connected to the heat pump body,
When the heat extraction / radiation in the underground heat exchanger reaches the set limit value, the heat pump main body is controlled by operation control means so as to use the auxiliary heat source. Use heat pump device. A geothermal heat utilization device comprising the underground heat utilization heat pump device according to any one of claims 1 to 4 and a load machine connected to a heat pump body of the geothermal heat utilization heat pump device,
The load machine is connected to another heat source device different from the heat pump main body, and when the heat extraction / radiation in the underground heat exchanger reaches the set limit value, the other heat source device is used. The geothermal heat utilization apparatus is characterized in that heat is supplied to the load machine or heat is absorbed from the load machine. An underground heat exchanger embedded in the ground, a heat pump main body connected to the underground heat exchanger, and a pipe for circulating the heat transfer water by connecting the underground heat exchanger and the heat pump. Comprising, a control method of a heat pump device using geothermal heat that collects heat from the ground or dissipates heat to the ground via the ground heat exchanger,
The measurement process to measure the thermal condition of the ground, the limit value setting process to set the limit value of heat extraction based on the measured thermal condition of the ground, and the heat pump body so as not to exceed the set limit value of heat extraction A control method for a heat pump device using geothermal heat, comprising an operation control step for controlling the operation of the ground heat.

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