JP5356900B2 - Geothermal heat pump device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a geothermal heat pump device enabling totally efficient operation by optimally collecting underground heat. <P>SOLUTION: During load operation, a control means 18 increases the rotational frequency of a geothermal circulating pump 11 when a temperature gradient of heating medium temperature detected by an underground going temperature detection means 12 or an underground return temperature detection means 13 is a downward pitch, and reduces the rotational frequency of the geothermal circulating pump 11 when the temperature gradient of the heating medium temperature detected by the underground going temperature detection means 12 or the underground return temperature detection means 13 is an upward pitch. Thus, the magnitude of changing load and the underground state can be recognized by the underground going temperature detection means 12 or the underground return temperature detection means 13, and the rotational frequency of the geothermal circulating pump 11 can be set so as to achieve a circulation flow rate to secure heat collection amount necessary for the load. As a result, without causing excessive heat collection and shortage of heat collection, optimal heat collection can be achieved, so as to improve the total efficiency of the geothermal heat pump device. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a geothermal heat pump device that uses geothermal heat whose temperature is relatively stable throughout the year through a heat pump.

  Conventionally, this type of geothermal heat pump device includes a heat pump unit 101 such as an air conditioner and a geothermal heat exchange unit 102 as shown in FIG. A plurality of underground heat exchangers 103 buried in parallel and connected in parallel to each other, a ground heat circulation circuit 104 that connects the heat pump unit 101 and the ground heat exchanger 103 in a circulating manner, and a ground heat circulation circuit 104 is provided with a geothermal circulation pump 105 that circulates a circulating fluid as a heat medium, and when the heating or cooling operation is started by driving the heat pump unit 101, the geothermal circulation pump 105 is driven. The circulating fluid is circulated through the underground heat circulation circuit 104 to collect heat from the ground or dissipate it into the ground via the underground heat exchanger 103. (For example, refer to Patent Document 1.)

  In such a geothermal heat pump device, before the construction of the device, a thermal response test is performed to grasp the thermal conductivity in the ground G, the amount of heat that can be collected from the ground, and the amount of heat that can be dissipated into the ground. At present, the simulation is performed to determine the circulating flow rate of the circulating fluid circulating through the underground heat circulation circuit 104 to a fixed value that will be suitable for the land.

JP 2002-54850 A

  By the way, this conventional geothermal heat pump device has a fixed circulation flow rate. However, the actual temperature in the ground G, the amount of heat that can be collected from the ground, and the amount of heat that can be dissipated into the ground are determined by Depending on factors such as the operation status of the intermediate heat pump device, it is not constant, and depending on the circulation flow rate determined in advance before the installation of the device, the heat collection amount or the heat radiation amount is insufficient for the heating operation or cooling operation of the heat pump unit 101. Alternatively, there is a possibility that the heat collection amount or the heat radiation amount may be excessive, and there is a possibility that the efficiency of the total underground heat pump device is lowered because the optimum heat collection and heat radiation cannot be performed.

In order to solve the above-mentioned problems, the present invention is particularly configured in claim 1 with a heat pump circuit in which a compressor, a load-side heat exchanger, a pressure reducing means, and a heat-source-side heat exchanger are connected in a ring shape with refrigerant piping, A plurality of underground heat exchangers embedded in and connected in parallel or in series with each other, and a underground heat circulation circuit that connects the underground heat exchanger and the heat source side heat exchanger in a circulatory manner, A ground heat circulation pump that circulates the heat medium in the ground heat circulation circuit, a ground temperature detecting means for detecting the temperature of the heat medium flowing into the ground heat exchanger, and an outflow from the ground heat exchanger A ground return temperature detecting means for detecting the temperature of the heated heat medium, and a control means for controlling the operation thereof, collecting ground heat by the ground heat exchanger, and evaporating the heat source side heat exchanger. And function the load side heat exchanger as a condenser. In the geothermal heat pump device that performs load operation for heating the load side, during the load operation, the control means detects the temperature of the heat medium temperature detected by the underground return temperature detection means or the underground return temperature detection means When the gradient is a downward gradient, the rotational speed of the underground heat circulation pump is increased, and the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is In the case of an upward gradient, the rotational speed of the geothermal circulation pump is decreased , and the control means increases the rotational speed of the underground thermal circulation pump as the degree of the downward gradient of the temperature gradient increases. The amount was to be increased .

According to a second aspect of the present invention, the control means increases the amount of decrease in the rotational speed of the underground heat circulation pump as the degree of the upward gradient of the temperature gradient increases.

Further, in claim 3, a heat pump circuit in which a compressor, a load-side heat exchanger, a pressure reducing means, and a heat source-side heat exchanger are connected in an annular shape with a refrigerant pipe, and a plurality of buried in the ground and connected in parallel or in series with each other An underground heat exchanger, an underground heat circulation circuit that connects the underground heat exchanger and the heat source side heat exchanger in a circulating manner, and a ground medium that circulates a heat medium in the underground heat circulation circuit Medium heat circulation pump, underground temperature detection means for detecting the temperature of the heat medium flowing into the underground heat exchanger, underground return temperature detection for detecting the temperature of the heat medium flowing out of the underground heat exchanger Means, and control means for controlling these operations, the ground heat exchanger collects ground heat, the heat source side heat exchanger functions as an evaporator, and the load side heat exchanger is Geothermal heat that performs load operation to function as a condenser and heat the load side In the pump device, during the load operation, the control means, when the temperature gradient of the heating medium temperature detected by the underground return temperature detection means or the underground return temperature detection means is a downward gradient, When the temperature gradient of the heating medium temperature detected by the underground return temperature detection means or the underground return temperature detection means is an upward gradient, the number of revolutions of the circulation pump is increased. Further, the control means increases the amount of decrease in the rotation speed of the underground heat circulation pump as the degree of the upward gradient of the temperature gradient increases.

  Further, in claim 4, during the load operation, when the heat medium temperature detected by the underground going-out temperature detection means becomes lower than the lower limit temperature set in advance based on the concentration of the heat medium, The number of rotations of the underground heat circulation pump was increased.

Moreover, in Claim 5, the heat pump circuit which connected the compressor, the load side heat exchanger, the pressure reduction means, and the heat source side heat exchanger cyclically | annularly with refrigerant | coolant piping, and the some which were embed | buried in the ground and were mutually connected in parallel or in series An underground heat exchanger, an underground heat circulation circuit that connects the underground heat exchanger and the heat source side heat exchanger in a circulating manner, and a ground medium that circulates a heat medium in the underground heat circulation circuit Medium heat circulation pump, underground temperature detection means for detecting the temperature of the heat medium flowing into the underground heat exchanger, underground return temperature detection for detecting the temperature of the heat medium flowing out of the underground heat exchanger And a control means for controlling these operations, and radiates heat to the ground by the underground heat exchanger, functions the heat source side heat exchanger as a condenser, and evaporates the load side heat exchanger. The geothermal heat pump that performs load operation to cool the load side by functioning as a In the load device, during the load operation, when the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is an upward gradient, the control means The number of rotations of the circulation pump is increased, and when the temperature gradient of the heating medium temperature detected by the underground return temperature detection means or the underground return temperature detection means is a downward gradient, the underground heat circulation pump Further, the control means increases the amount of increase in the rotation speed of the underground heat circulation pump as the degree of the upward gradient of the temperature gradient increases .

According to a sixth aspect of the present invention, the control means increases the amount of decrease in the rotational speed of the underground heat circulation pump as the degree of the downward gradient of the temperature gradient increases.

Further, in claim 7, a heat pump circuit in which a compressor, a load-side heat exchanger, a pressure reducing means, and a heat source-side heat exchanger are connected in an annular shape with a refrigerant pipe, and a plurality of buried in the ground and connected in parallel or in series with each other An underground heat exchanger, an underground heat circulation circuit that connects the underground heat exchanger and the heat source side heat exchanger in a circulating manner, and a ground medium that circulates a heat medium in the underground heat circulation circuit Medium heat circulation pump, underground temperature detection means for detecting the temperature of the heat medium flowing into the underground heat exchanger, underground return temperature detection for detecting the temperature of the heat medium flowing out of the underground heat exchanger And a control means for controlling these operations, and radiates heat to the ground by the underground heat exchanger, functions the heat source side heat exchanger as a condenser, and evaporates the load side heat exchanger. The geothermal heat pump that performs load operation to cool the load side by functioning as a In the load device, during the load operation, when the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is an upward gradient, the control means The number of rotations of the circulation pump is increased, and when the temperature gradient of the heating medium temperature detected by the underground return temperature detection means or the underground return temperature detection means is a downward gradient, the underground heat circulation pump Further, the control means increases the amount of decrease in the rotational speed of the underground heat circulation pump as the degree of the downward gradient of the temperature gradient increases.

According to the first aspect of the present invention, during the load operation, when the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is a downward gradient, the control means In addition to increasing the rotation speed of the heat circulation pump, if the temperature gradient of the heating medium temperature detected by the underground return temperature detection means or the underground return temperature detection means is an upward gradient, the rotation of the underground heat circulation pump The number of loads is reduced, and the magnitude of the load and the underground state that change from moment to moment are monitored and grasped by the underground temperature detecting means or the underground return temperature detecting means, and when the temperature gradient is a downward gradient, that is, When the load of load operation increases or the amount of heat that can be collected from the ground decreases, the number of rotations of the underground heat circulation pump is increased to ensure the amount of heat collected for the load. To achieve the minimum circulating flow rate The number of rotations of the intermediate heat circulation pump can be set, and when the temperature gradient is ascending, that is, when the load of load operation is reduced or the amount of heat that can be collected from the ground is increased, The rotation speed of the geothermal circulation pump can be set to reduce the rotation speed of the geothermal circulation pump so that the minimum circulation flow rate is ensured to secure the required amount of heat for the load. without too hot adopted, also, without even insufficient heating adopted, it is best Tonetsu state, and are not capable of improving the efficiency of the overall geothermal heat pump device, further control means, The amount of increase in the rotation speed of the underground heat circulation pump is increased as the degree of the downward gradient of the temperature gradient increases. Here, the degree of the downward gradient of the temperature gradient means how far it is from the circulation flow rate to secure the necessary amount of heat for the load, that is, the amount of heat collected is insufficient. The means increases the amount of increase in the number of rotations of the geothermal circulation pump as the degree of the downward gradient of the temperature gradient increases, so that the circulation flow rate for securing the heat collection amount necessary for the load is obtained. The number of rotations of the intermediate heat circulation pump can be brought close quickly and accurately, whereby optimum heat collection can be performed, and the efficiency of the overall geothermal heat pump device can be improved.

Further, according to claim 2, the control means is designed so as to increase the amount of reduction of the rotational speed of the larger degree geothermal heat circulating pump of upslope of the temperature gradient. Here, the magnitude of the degree of the temperature gradient rising means how far away from the circulation flow rate to secure the necessary amount of heat for the load, that is, the amount of heat collected is excessive. means, by increasing the amount of decrease of the rotational speed of the larger degree geothermal heat circulating pump of upslope of the temperature gradient, the ground so that the circulation flow rate to ensure adopting heat required for the load The rotational speed of the intermediate heat circulation pump can be brought close quickly and accurately, whereby optimum heat collection can be performed, and the efficiency of the overall geothermal heat pump device can be improved.

According to the third aspect of the present invention, during the load operation, the control means detects the underground heat when the temperature gradient of the heat medium temperature detected by the underground return temperature detection means or the underground return temperature detection means is a downward gradient. In addition to increasing the rotation speed of the circulation pump, if the temperature gradient of the heating medium temperature detected by the underground return temperature detection means or the underground return temperature detection means is an upward gradient, the rotation speed of the underground heat circulation pump Therefore, when the temperature gradient is a downward gradient, that is, by monitoring and grasping the magnitude of the load that changes from moment to moment and the underground state with the underground temperature detection means or the underground return temperature detection means, that is, If the load of the load operation increases or the amount of heat that can be collected from the ground decreases, the minimum number of times to increase the number of rotations of the underground heat circulation pump and secure the necessary amount of heat for the load Underground so that the circulation flow is limited The number of rotations of the circulation pump can be set, and when the temperature gradient is ascending, that is, when the load of load operation decreases or the amount of heat that can be collected from the ground increases, The number of rotations of the geothermal circulation pump can be set to reduce the number of rotations of the heat circulation pump so that the minimum circulation flow rate is ensured to ensure the amount of heat collected for the load. It is possible to achieve optimum heat collection without excessive or insufficient heat collection, and to improve the efficiency of the overall geothermal heat pump device . The amount of decrease in the number of rotations of the underground heat circulation pump is increased as the degree of the upward gradient increases. Here, the magnitude of the degree of the temperature gradient rising means how far away from the circulation flow rate to secure the necessary amount of heat for the load, that is, the amount of heat collected is excessive. The means increases the amount of decrease in the number of rotations of the geothermal circulation pump as the degree of the temperature gradient increases, so that the circulation flow rate is ensured so as to ensure the amount of heat collected for the load. The rotational speed of the intermediate heat circulation pump can be brought close quickly and accurately, whereby optimum heat collection can be performed, and the efficiency of the overall geothermal heat pump device can be improved.

  According to the fourth aspect, during the load operation, when the temperature of the heating medium detected by the underground temperature detecting means becomes lower than the lower limit temperature set in advance based on the concentration of the heating medium, By increasing the rotation speed of the intermediate heat circulation pump, the amount of heat collected is increased and the underground temperature going to the underground heat exchanger is raised, so that the freezing of the heating medium can be prevented and the temperature of the heating medium is lowered. The increase in the viscosity of the heat transfer medium due to heat and the increase in the operating load of the underground heat circulation pump can be prevented, and the increase in the power consumption of the underground heat circulation pump can be prevented. Can be prevented.

Further, according to claim 5, during the load operation, the control means detects the heat generated when the temperature gradient of the heating medium temperature detected by the underground temperature detecting means or the underground return temperature detecting means is an upward gradient. In addition to increasing the rotation speed of the circulation pump, if the temperature gradient of the heating medium temperature detected by the underground return temperature detection means or the underground return temperature detection means is a downward gradient, the rotation speed of the underground heat circulation pump Therefore, when the temperature gradient is an upward gradient, that is, by monitoring and grasping the magnitude of the load and the state of the ground that change every moment with the underground temperature detection means or the underground return temperature detection means, that is, When the load of load operation increases or the amount of heat that can be dissipated into the ground decreases, increase the rotation speed of the underground heat circulation pump so that the minimum circulating flow rate required for the load is reached. Set the rotation speed of the underground heat circulation pump If the temperature gradient is downward, that is, if the load during load operation decreases or the amount of heat that can be dissipated into the ground increases, the rotational speed of the underground heat circulation pump is decreased. Therefore, the rotation speed of the underground heat circulation pump can be set so that the minimum circulating flow rate for securing the necessary heat dissipation amount for the load can be set. without even missing, it is optimum heat dissipation state, and are not capable of improving the efficiency of the overall geothermal heat pump device, further control means, the ground larger the degree of the upward gradient of the temperature gradient The increase in the number of rotations of the intermediate heat circulation pump is increased. Here, the magnitude of the degree of the rising temperature gradient means how far it is from the circulation flow rate to secure the necessary heat dissipation for the load, that is, the amount of heat dissipation is insufficient. The means is to increase the amount of increase in the number of rotations of the underground heat circulation pump as the degree of the temperature gradient increases, so that the circulation flow rate is ensured to ensure the necessary heat dissipation for the load. The number of rotations of the heat circulation pump can be brought close quickly and accurately, whereby optimum heat radiation can be achieved, and the efficiency of the overall underground heat pump device can be improved.

According to the sixth aspect of the present invention, the control means increases the amount of decrease in the rotational speed of the underground heat circulation pump as the degree of the downward gradient of the temperature gradient increases. Here, the degree of the downward gradient of the temperature gradient means how far it is from the circulation flow rate to secure the necessary heat dissipation for the load, that is, the amount of heat dissipation is excessive. The means is to increase the amount of decrease in the number of rotations of the underground heat circulation pump as the degree of downward gradient of the temperature gradient increases, so that the circulation flow rate is ensured to ensure the necessary heat dissipation for the load. The number of rotations of the heat circulation pump can be brought close quickly and accurately, whereby optimum heat radiation can be achieved, and the efficiency of the overall underground heat pump device can be improved.

According to the seventh aspect of the present invention, during the load operation, when the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is an upward gradient, the control means In addition to increasing the rotation speed of the circulation pump, if the temperature gradient of the heating medium temperature detected by the underground return temperature detection means or the underground return temperature detection means is a downward gradient, the rotation speed of the underground heat circulation pump Therefore, when the temperature gradient is an upward gradient, that is, by monitoring and grasping the magnitude of the load and the state of the ground that change every moment with the underground temperature detection means or the underground return temperature detection means, that is, When the load of load operation increases or the amount of heat that can be dissipated into the ground decreases, increase the rotation speed of the underground heat circulation pump so that the minimum circulating flow rate required for the load is reached. Set the rotation speed of the underground heat circulation pump If the temperature gradient is downward, that is, if the load during load operation decreases or the amount of heat that can be dissipated into the ground increases, the rotational speed of the underground heat circulation pump is decreased. Therefore, the rotation speed of the underground heat circulation pump can be set so that the minimum circulating flow rate for securing the necessary heat dissipation amount for the load can be set. It is possible to achieve optimal heat dissipation without any shortage, and to improve the efficiency of the overall geothermal heat pump device. The amount of decrease in the rotational speed of the heat circulation pump is increased. Here, the degree of the downward gradient of the temperature gradient means how far away from the circulation flow rate to secure the necessary heat dissipation for the load, that is, the amount of heat dissipation is excessive. The means is to increase the amount of decrease in the number of rotations of the underground heat circulation pump as the degree of downward gradient of the temperature gradient increases, so that the circulation flow rate is ensured to ensure the necessary heat dissipation for the load. The number of rotations of the heat circulation pump can be brought close quickly and accurately, whereby optimum heat radiation can be achieved, and the efficiency of the overall underground heat pump device can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the geothermal heat pump apparatus of one Embodiment of this invention. The flowchart which shows the action | operation at the time of the load driving | operation of the same embodiment. The time chart which shows the action | operation at the time of the load driving | operation of the same embodiment. Schematic when the load operation of the same embodiment is a boiling operation for heating and boiling hot water used for hot water supply or the like. Schematic when the load operation of the same embodiment is a heating operation in which an air-conditioned space is warmed by an indoor unit for air conditioning. The schematic block diagram of the geothermal heat pump apparatus of other embodiment of this invention. The flowchart which shows the action | operation at the time of the load driving | running of other embodiment. The time chart which shows the action | operation at the time of load driving | running of the other embodiment. The schematic block diagram of the conventional geothermal heat pump apparatus.

Next, a geothermal heat pump device according to an embodiment of the present invention will be described with reference to FIG.
As shown in the drawing, the underground heat pump device of the present embodiment is roughly composed of a heat pump unit 1, an underground heat exchange unit 2, and a load heat exchange unit 3.

  The heat pump unit 1 circulates a variable capacity compressor 4 for compressing a refrigerant and a high-pressure refrigerant discharged from the compressor 4 to exchange heat between the high-pressure refrigerant and a load-side heat medium of the load heat exchange unit 3. A load-side heat exchanger 5 as a condenser to be performed, an expansion valve 6 as a decompression means for decompressing the refrigerant flowing out from the load-side heat exchanger 5, and a low-pressure refrigerant from the expansion valve 6 is circulated and this low-pressure refrigerant and ground A heat source side heat exchanger 7 serving as an evaporator for exchanging heat with the heat medium on the heat source side of the intermediate heat exchanging unit 2, and these are connected in a ring shape with a refrigerant pipe to form a heat pump circuit 8. is there. In addition, as a refrigerant | coolant of the heat pump unit 1, arbitrary refrigerant | coolants, such as a carbon dioxide refrigerant | coolant and a HFC refrigerant | coolant, can be used.

  The underground heat exchange unit 2 includes a heat source side heat exchanger 7, a plurality of underground heat exchangers 9 embedded in the ground G and connected in parallel to each other, and the heat source side heat exchanger 7 and the underground heat exchange. A geothermal circulation circuit 10 that is connected to the vessel 9 so as to circulate, a geothermal circulation pump 11 having a variable rotation speed that circulates an antifreeze liquid as a heating medium in the geothermal circulation circuit 10, and a geothermal circulation. A ground temperature sensor 12 serving as a ground temperature detecting means for detecting the temperature of the antifreeze liquid that is provided in the circuit 10 and is discharged from the ground heat circulation pump 11 and flows into the ground heat exchanger 9, and the underground heat circulation An underground return temperature sensor 13 serving as an underground return temperature detecting means for detecting the temperature of the antifreeze liquid that is provided in the circuit 10 and flows out of the underground heat exchanger 9 is provided.

  Here, in the underground heat exchanging section 2, the underground heat is collected from the ground G by the underground heat exchanger 9, and the antifreeze liquid with the heat is exchanged by the underground heat circulation pump 11 for heat source side heat exchange. Is supplied to the vessel 7. Then, the heat and the antifreeze liquid flow in the heat source side heat exchanger 7 to face each other to exchange heat, and the underground heat collected by the underground heat exchanger 9 is pumped to the refrigerant side of the heat pump unit 1. Thus, the heat source side heat exchanger 7 functions as an evaporator.

  The load heat exchanging unit 3 includes the load side heat exchanger 5 that applies heat to the load terminal 14 side, a load terminal 14 such as a floor heating panel that heats the air-conditioned space, the load side heat exchanger 5 and the load terminal. 14 is connected to the load side circulation circuit 15, the load side circulation circuit 15 circulates the circulating fluid for heating, and the load side circulation circuit 15 branched for each load terminal 14. A thermal valve 17 (17a, 17b) that controls the supply of the circulating fluid for heating to the load terminal 14 by opening and closing thereof is provided.

  A remote control (not shown) is installed in each air-conditioned space heated by the load terminal 14, and when the remote controller gives instructions to heat the air-conditioned space, the compressor 4 and the load-side circulation pump 16 is started, and a load operation is performed in which the load side heat exchanger 5 functions as a condenser to heat the load side. During the load operation, in the load-side heat exchanger 5, the refrigerant and the heating circulating fluid flow oppositely to perform heat exchange, and the heating circulating fluid heated in the load-side heat exchanger 5 is The air-conditioned space that is sent to the load terminal 14 via the thermal valve 17 and received an instruction from the remote controller is heated.

  18 controls the driving of the actuators such as the compressor 4, the expansion valve 6, and the underground heat circulation pump 11 in response to the inputs from the underground temperature sensor 12 and the underground return temperature sensor 13 and signals from the remote controller. It is a control means which has a microcomputer and comprises a control part, and controls the said load driving | operation.

Next, the operation during the load operation of the embodiment shown in FIG. 1 will be described based on the flowchart shown in FIG.
When the load terminal 14 instructs the heating of the air-conditioned space by the remote controller, the control means 18 starts driving the compressor 4, the geothermal circulation pump 11, and the load-side circulation pump 16, and performs the load operation. The heating operation is started. Here, the underground heat circulation pump 11 is started to be driven at a preset initial rotation speed. In the load-side heat exchanger 5, heat is exchanged between the heating circulating fluid circulated by the load-side circulation pump 16 and the high-temperature and high-pressure refrigerant discharged from the compressor 4, and the heated heating circulating fluid is loaded into the load terminal 14 In the heat source side heat exchanger 7, the anti-freezing liquid circulated by the ground heat circulation pump 11 and collected the ground heat through the ground heat exchanger 9 and the expansion valve 6 are heated. Heat is exchanged with the discharged low-temperature and low-pressure refrigerant, and the refrigerant is heated and evaporated by underground heat.

  When the heating operation is performed, the temperature of the antifreeze liquid is detected by the underground temperature sensor 12, and the control means 18 stores the temperature A of the antifreeze liquid at that time (step S1), and a predetermined time T, for example, 1 minute has elapsed. If the control means 18 determines that the predetermined time T has elapsed, the underground temperature sensor 12 detects the temperature of the antifreeze liquid, and the control means 18 detects the temperature of the antifreeze liquid at that time. B is stored (step S3), and a temperature gradient (B−A) / T per predetermined time T is calculated based on the temperature A and the temperature B stored in step S1 and step S3 (step S4). .

  Subsequently, the control means 18 determines whether or not the temperature gradient calculated in step S4 is (BA) / T <0 and is a downward gradient (step S5), and the temperature gradient is a downward gradient. When it is determined, it is determined whether or not the degree of the temperature gradient descending is greater than or equal to a preset value α (step S6), and it is determined that the degree of the temperature gradient descending is greater than or equal to the preset set value α. The rotation speed of the underground heat circulation pump 11 is increased by a rotation, for example, 30 rpm, from the previous rotation speed (step S7), and the process returns to step 1. On the other hand, in step S6, the temperature gradient is increased. If it is determined that the degree of the downward gradient is smaller than the preset value α, the rotational speed of the geothermal circulation pump 11 is increased by b rotation, for example, 10 rpm from the previous rotational speed (step S8). It is intended to return to the processing-flops 1. Note that the a rotation in step S7 and the b rotation in step S8 have a relationship of a rotation> b rotation.

  In step S5, when the control means 18 determines that the temperature gradient is not a downward gradient, the controller 18 determines whether the temperature gradient calculated in step S4 is an upward gradient at (BA) / T> 0. If it is determined that the temperature gradient is an upward gradient (step S9), it is determined whether or not the degree of the temperature gradient is equal to or higher than a preset value β (step S10). If it is determined that the degree is equal to or higher than the preset set value β, the rotation speed of the geothermal circulation pump 11 is reduced by c rotation, for example, 30 rpm, from the rotation speed until then (step S11), and the process returns to step 1 above. On the other hand, if it is determined in step S10 that the degree of the upward gradient of the temperature gradient is smaller than the preset set value β, the rotational speed of the geothermal circulation pump 11 is determined so far. Ri d rotation, for example, by 10rpm reduced (step S12), the one in which the flow returns to the process step 1. Note that the c rotation in step S11 and the d rotation in step S12 have a relationship of c rotation> d rotation.

  Further, in step S9, the control means 18 has a temperature gradient that is not ascending, that is, the temperature gradient calculated in step S4 is (B−A) / T = 0 or small enough to be regarded as having no temperature gradient. If it is determined that the value is a value, the rotation speed of the underground heat circulation pump 11 is maintained (step S13), and the process returns to step S1.

  During the heating operation, when the temperature of the antifreeze liquid detected by the underground temperature sensor 12 is lower than the lower limit temperature set in advance based on the concentration of the antifreeze liquid in Step S1 or Step S3. In step S3, the rotation speed of the geothermal circulation pump 11 is increased by a predetermined amount from the rotation speed up to that point, and the process returns to step S1.

  Next, the load operation shown in the flowchart of FIG. 2 will be described in detail with reference to the time chart of FIG. Here, as initial conditions, the set value α = 2, the set value β = 2, the lower limit temperature = 0 ° C., and the rotation speed of the geothermal circulation pump 11 at time t0 = 1000 rpm.

  First, at time t0, the control means 18 detects the temperature of the antifreeze liquid with the underground temperature sensor 12, stores the detected temperature, here 4 ° C., as the temperature A (step S1), and between the times t0 and t1. It is determined whether or not a predetermined time T, for example, 1 minute has elapsed (step S2), and if it is determined that 1 minute has elapsed, the control means 18 sends the underground temperature sensor 12 at time t1. The temperature of the antifreeze is detected, and the detected temperature, here 4 ° C., is stored as the temperature B (step S3), and a temperature gradient (BA) / T = (4-4) / 1 = 0 is calculated ( In step S4), in step S5, it is determined that the temperature gradient calculated in step S4 is not a downward gradient, and the process proceeds to step S9. In step S9, the temperature gradient calculated in step S4 is not an upward gradient. Judgment The process proceeds to step S13, to maintain the 1000rpm was speed geothermal heat circulation pump 11 so far, in which the process returns to the step S1.

  Next, at time t1, the control means 18 detects the temperature of the antifreeze liquid with the underground temperature sensor 12, stores the detected temperature, here 4 ° C., as the temperature A (step S1), and from time t1 to t2. It is determined whether or not 1 minute has elapsed (step S2). If it is determined that 1 minute has elapsed, the control means 18 detects the temperature of the antifreeze liquid at the underground temperature sensor 12 at time t2. The detected temperature, here 2 ° C. is stored as the temperature B (step S3), the temperature gradient (BA) / T = (2-4) / 1 = −2 is calculated (the step S4), It is determined that the temperature gradient calculated in step S4 is a downward gradient (step S5), and the degree of the downward gradient of the temperature gradient is 2, and it is determined that the preset value α = 2 or more (the step). S6), rotation of the underground heat circulation pump 11 The a rotation from the rotation speed of the far, for example, by 30rpm increased as 1030Rpm (the step S7), and those returning to the processing step 1.

  Subsequently, at time t2, the control means 18 detects the temperature of the antifreeze liquid with the underground temperature sensor 12, stores the detected temperature, here 2 ° C., as the temperature A (step S1), and from time t2 to t3. It is determined whether or not one minute has elapsed (step S2). If it is determined that one minute has elapsed, at time t3, the control means 18 detects the temperature of the antifreeze using the underground temperature sensor 12. The detected temperature, here 1 ° C. is stored as the temperature B (step S3), the temperature gradient (B−A) / T = (1-2) / 1 = −1 is calculated (the step S4), It is determined that the temperature gradient calculated in step S4 is a downward gradient (step S5), and the degree of the downward gradient of the temperature gradient is 1 and is determined to be smaller than a preset set value α = 2 (the step S6). ), The operation of the underground heat circulation pump 11 b rotation than the rotation speed of the number to it, for example 10rpm increased as a 1040Rpm (the step S8), and those returning to the processing step 1.

  Further, from time t3 to t4, processing is performed in the order of step S1, step S2, step S3, step S4, step S5, step S9, step S13, and the process returns to step S1. .

  Next, at time t4, the control means 18 detects the temperature of the antifreeze liquid with the underground temperature sensor 12, stores the detected temperature, here 1 ° C. as the temperature A (step S1), and from time t4 to time t5. It is determined whether or not 1 minute has elapsed (step S2). If it is determined that 1 minute has elapsed, the control means 18 detects the temperature of the antifreeze liquid at the underground temperature sensor 12 at time t2. The detected temperature, here −1 ° C., is stored as the temperature B (step S3). Here, during the heating operation, in step S1 or step S3, the temperature of the antifreeze liquid detected by the underground temperature sensor 12 was lower than a preset lower limit temperature based on the concentration of the antifreeze liquid. In this case, since the rotation speed of the underground heat circulation pump 11 is increased by a predetermined amount from the rotation speed up to that time at the timing of step S3, the underground temperature sensor 12 is informed at time t5 which is the timing of step S3. Since the temperature of the antifreeze detected in this step is lower than the preset lower limit temperature = 0 ° C. based on the concentration of the antifreeze, the rotation speed of the underground heat circulation pump 11 is set to a predetermined amount, here 30 rpm. The pressure is increased to 1070 rpm, and the process returns to step S1.

  Subsequently, at time t5, the control means 18 detects the temperature of the antifreeze liquid with the underground temperature sensor 12, stores the detected temperature, here −1 ° C., as the temperature A (step S1), and from time t5 to t6. It is determined whether or not 1 minute has elapsed (step S2). If it is determined that 1 minute has elapsed, the control means 18 detects the temperature of the antifreeze liquid at the underground temperature sensor 12 at time t6. The detected temperature, here 0 ° C., is stored as the temperature B (step S3). Here, since the temperature of the antifreeze liquid detected by the underground temperature sensor 12 at the time t5 which is the timing of the step S1 is lower than the lower limit temperature set in advance based on the concentration of the antifreeze liquid, the step S3 At time t6, the rotational speed of the geothermal circulation pump 11 is increased by 30 rpm from the previous rotational speed to 1100 rpm, and after waiting for a predetermined time, for example, 1 minute, the processing of step S1 is performed. It is a return.

  Further, at time t6, the control means 18 detects the temperature of the antifreeze liquid with the underground temperature sensor 12, stores the detected temperature, here 0 ° C., as the temperature A (step S1), and between time t6 and time t7. (Step S2), if it is determined that 1 minute has elapsed, at time t7, the control means 18 detects the temperature of the antifreeze liquid at the underground temperature sensor 12, The detected temperature, here 2 ° C., is stored as temperature B (step S3), temperature gradient (BA) / T = (2-0) / 1 = 2 is calculated (step S4), and step S4. (Step S5), the temperature gradient calculated in step S4 is determined to be an upward gradient (step S9), and the degree of the temperature gradient is 2 And set in advance It is determined that the set value β = 2 or more (step S10), and the rotation speed of the geothermal circulation pump 11 is reduced by c rotation, for example, 30 rpm to 1070 rpm (step S11). It returns to the process of the said step 1.

  Next, at time t7, the control means 18 detects the temperature of the antifreeze with the underground temperature sensor 12, stores the detected temperature, here 2 ° C., as the temperature A (step S1), and from time t7 to t8. It is determined whether or not 1 minute has elapsed (step S2). If it is determined that 1 minute has elapsed, the control means 18 detects the temperature of the antifreeze liquid at the underground temperature sensor 12 at time t8. The detected temperature, here 3 ° C. is stored as the temperature B (step S3), the temperature gradient (BA) / T = (3-2) / 1 = 1 is calculated (step S4), and the step It is determined that the temperature gradient calculated in S4 is not a downward gradient (step S5), the temperature gradient calculated in step S4 is determined to be an upward gradient (step S9), and the degree of the upward gradient of the temperature gradient is determined. 1 and set in advance It is determined that the set value β is smaller than 2 (step S10), and the rotation speed of the geothermal circulation pump 11 is reduced by d rotation, for example, 10 rpm to 1060 rpm (step S12). It returns to the process of 1.

  Subsequently, during the period from time t8 to t9, as in the period from time t0 to t1, and from time t3 to time t4, the step S1, the step S2, the step S3, the step S4, the step S5, and the step S5. Processing is performed in the order of step S9 → step S13, and the process returns to step S1.

  In the heating operation as the load operation described above, the control unit 18 obtains a temperature gradient per predetermined time based on the temperature of the antifreeze liquid detected by the underground temperature sensor 12 in the step S1 to the step S4. If it is determined in step S5 that the calculated temperature gradient is a downward gradient, the rotational speed of the underground heat circulation pump 11 is increased from the rotational speed up to that point, and in steps S1 to S4. Then, based on the heat medium temperature detected by the underground temperature sensor 12, a temperature gradient per predetermined time is obtained, and if the calculated temperature gradient is determined to be an upward gradient in step S9, the underground heat circulation pump 11 is determined. The number of rotations is reduced from the previous number of rotations, so the magnitude of the load that changes from moment to moment is monitored by the underground temperature sensor 12. Then, when the temperature gradient is a downward gradient, that is, when the heating operation load is increased, the rotation speed of the underground heat circulation pump 11 is increased more than the rotation speed so far to eliminate the temperature gradient. In addition, the rotational speed of the underground heat circulation pump 11 can be set so that the minimum circulation flow rate for securing the heat collection amount necessary for the load can be obtained, and the temperature gradient is an upward gradient. That is, when the load of the load operation decreases, the number of rotations of the underground heat circulation pump 11 is decreased from the number of rotations up to that point, and the necessary sampling is performed in the direction of eliminating the temperature gradient and with respect to the load. The number of rotations of the underground heat circulation pump 11 can be set so that the minimum circulation flow rate for securing the amount of heat can be obtained, and it is possible to obtain an optimum sampling without excessive heat collection or insufficient heat collection. Comprehensive underground heat pump that can generate heat It is capable of improving the efficiency of the device.

  Further, when the control means 18 determines that the temperature gradient calculated in step S4 is a downward gradient, whether or not the degree of the downward gradient of the temperature gradient is equal to or larger than a preset set value α in step S6. Therefore, when the degree of the downward gradient of the temperature gradient is equal to or greater than the set value α, the amount of increase in the rotation speed of the underground heat circulation pump 11 is increased as compared with the case where the temperature gradient is smaller than the set value α. Here, the magnitude of the degree of the downward gradient of the temperature gradient means how far it is from the circulation flow rate for securing the necessary heat collection amount for the load, that is, the lack of heat collection amount, When the amount of collected heat is largely insufficient, the rotational speed of the underground heat circulation pump 11 is greatly increased as in step S7, and when the amount of collected heat is slightly insufficient, the ground is extracted as in step S8. The rotational speed of the intermediate heat circulation pump 11 is increased by a small amount. Therefore, the control means 18 increases the amount of increase in the number of rotations of the underground heat circulation pump 11 as the degree of the downward gradient of the temperature gradient increases, and thereby the circulation flow rate for ensuring the necessary heat collection amount for the load. Thus, the rotational speed of the underground heat circulation pump 11 can be brought close quickly and accurately, whereby optimum heat collection can be performed and the efficiency of the overall underground heat pump device can be improved. .

  If the control means 18 determines that the temperature gradient calculated in step S4 is an upward gradient, whether or not the degree of the upward gradient of the temperature gradient is equal to or greater than a preset set value β in step S10. If the degree of the upward gradient of the temperature gradient is equal to or greater than the set value β, the amount of decrease in the rotation speed of the geothermal circulation pump 11 is made larger than when the temperature gradient is smaller than the set value β. Here, the magnitude of the upward gradient of the temperature gradient means how far it is from the circulation flow rate for securing the necessary heat collection amount for the load, that is, the excessive amount of heat collection amount, If the amount of heat collected is too large, the rotational speed of the underground heat circulation pump 11 is greatly reduced as in step S11. If the amount of heat collected is slightly larger, the amount of heat collected in the underground heat circulation pump 11 as in step S12. The rotational speed is reduced by a small amount. Therefore, the control means 18 increases the amount of decrease in the rotation speed of the geothermal circulation pump 11 as the degree of the upward gradient of the temperature gradient is increased, so that the circulation flow rate for ensuring the necessary heat collection amount for the load is obtained. Thus, the rotational speed of the underground heat circulation pump 11 can be brought close quickly and accurately, whereby optimum heat collection can be performed, and the efficiency of the overall underground heat pump device can be improved. .

  Further, during the heating operation, when the temperature of the antifreeze liquid detected by the underground temperature sensor 12 becomes lower than the lower limit temperature set in advance based on the concentration of the antifreeze liquid, the rotation of the underground heat circulation pump 11 is performed. The number is increased by a predetermined amount from the number of rotations so far. Here, if the temperature of the antifreeze falls below the preset minimum temperature based on the concentration of the antifreeze, the antifreeze may freeze, and the viscosity of the antifreeze increases and the pressure loss increases, so that geothermal circulation Since the operation load of the pump 11 increases, the power consumption for rotating the geothermal circulation pump 11 at the target rotational speed increases if the circulation flow rate necessary for circulation to the underground heat exchanger 9 is maintained. This would reduce the efficiency of the overall geothermal heat pump device. Therefore, when the temperature of the antifreeze detected by the underground temperature sensor 12 becomes lower than a preset lower limit temperature, the rotation speed of the underground heat circulation pump 11 is increased by a predetermined amount from the rotation speed until then. In order to increase the amount of heat collected and raise the temperature of the antifreeze liquid going from the heat source side heat exchanger 7 to the underground heat exchanger 9, the antifreeze liquid can be prevented from freezing and the increase in viscosity due to the temperature decrease of the antifreeze liquid is suppressed. An increase in the operating load of the geothermal circulation pump 11 can be prevented, an increase in power consumption of the geothermal circulation pump 11 can be prevented, and a decrease in the efficiency of the overall geothermal heat pump device can be prevented. It is something that can be done.

  Note that the present invention is not limited to the above-described embodiment, and the control of the present invention is applied during the heating operation in which the load terminal 14 such as a floor heating panel or the like is used to heat the air-conditioned room. As shown in FIG. 2, the load terminal 14 is a hot water storage tank 19 for storing hot water used for hot water supply or the like, and the control of the present invention may be applied to a boiling operation for boiling hot water in the hot water storage tank 19 as a load operation. In addition, as shown in FIG. 5, the control of the present invention may be applied to the heating operation by the indoor unit 20 for air conditioning as the load operation, and variously within a range not changing the gist of the present invention. Various modifications are possible and do not impede this.

  In the present embodiment, the plurality of underground heat exchangers 9 buried in the ground are connected in parallel to each other, but the plurality of underground heat exchangers 9 buried in the ground are connected in series to each other. It may be what has been done.

  Further, in this embodiment, the magnitude of the load that changes from moment to moment is monitored and grasped by the underground temperature sensor 12, but the flow of groundwater, the geothermal heat pump, even if the magnitude of the load does not change. The amount of heat that can be collected from the ground changes depending on factors such as the operating conditions of the device, and the temperature of the antifreeze detected by the underground temperature sensor 12 may change. When the temperature gradient is a downward gradient, that is, when the amount of heat that can be collected from the ground is reduced, the rotational speed of the underground heat circulation pump 11 is The rotation speed of the underground heat circulation pump 11 is increased in a direction that eliminates the temperature gradient and the minimum circulation flow rate for securing the necessary amount of heat collection with respect to the load. Can also be set, temperature gradient Is an upward gradient, that is, when the amount of heat that can be collected from the underground increases, the rotational speed of the underground heat circulation pump 11 is decreased from the rotational speed up to that point, in the direction of eliminating the temperature gradient, In addition, the rotation speed of the underground heat circulation pump 11 can be set so that the minimum circulating flow rate for securing the necessary amount of heat for the load can be obtained, and it is sufficient to collect heat without excessive heat collection. Without this, it is possible to obtain optimum heat and to improve the efficiency of the overall underground heat pump device.

  Further, in the present embodiment, the control means 18 obtains a temperature gradient per predetermined time based on the temperature of the antifreeze liquid detected by the underground temperature sensor 12 in the step S1 to the step S4, and uses the calculated temperature gradient. Although the increase / decrease control of the rotation speed of the geothermal circulation pump 11 is performed, the temperature of the antifreeze liquid detected by the underground return temperature sensor 13 is also changed to the underground level with respect to the load and the underground state that change every moment. Since the same tendency as the temperature of the antifreeze liquid detected by the temperature sensor 12 is shown, the control means 18 in step S1 to step S4 based on the temperature of the antifreeze liquid detected by the underground return temperature sensor 13 per predetermined time. The temperature gradient may be obtained, and the increase / decrease control of the rotation speed of the underground heat circulation pump 11 may be performed based on the calculated temperature gradient. The condition of the underground is monitored and grasped by the underground return temperature sensor 13, and the temperature gradient is downward, that is, when the load of the load operation increases or the amount of heat that can be collected from the underground decreases. Is a minimum circulation flow rate for increasing the number of rotations of the underground heat circulation pump 11 higher than the number of rotations up to that point and eliminating the temperature gradient and securing a necessary amount of heat collection for the load. The rotation speed of the underground heat circulation pump 11 can be set so that the temperature gradient is ascending, that is, the load of the load operation has decreased or the amount of heat that can be collected from the underground has increased. In such a case, the minimum number of circulations in order to reduce the number of rotations of the underground heat circulation pump 11 from the number of rotations up to that point, to eliminate the temperature gradient, and to secure the amount of heat collected for the load. Underground heat circulation so that the flow rate The number of rotations can be set to the number of revolutions 11, and it is possible to obtain optimum heat without excessive heat collection or insufficient heat collection, and to improve the efficiency of the overall geothermal heat pump device. It can be done.

  In the present embodiment, in step S6, the determination of the degree of the temperature gradient descending is performed by two choices of whether it is equal to or larger than a preset value α or smaller, and the geothermal circulation pump 11 Although the amount of increase in the rotational speed is determined, if the degree of increase in the rotational speed of the geothermal circulation pump 11 is increased as the degree of the downward gradient of the temperature gradient increases, for example, the temperature gradient When the degree of the downward gradient is 1, the rotational speed of the geothermal circulation pump 11 is increased by 10 rpm. When the degree of the downward gradient of the temperature gradient is 2, the rotational speed of the underground thermal circulation pump 11 is increased by 30 rpm. When the degree of downgradation of the temperature gradient is 3, the geothermal circulation pump 11 is judged from the degree of downgradation of the temperature gradient, such as increasing the rotational speed of the geothermal circulation pump 11 by 50 rpm. Increased rotation speed The amount may be determined by using three or more data tables. Similarly, in step S10, whether or not the determination of the degree of the temperature gradient is equal to or higher than a preset value β, The amount of decrease in the number of rotations of the geothermal circulation pump 11 is determined by two choices of smaller than that, but the number of rotations of the underground heat circulation pump 11 decreases as the degree of the temperature gradient increases. As long as the amount is increased, the amount of decrease in the rotation speed of the geothermal circulation pump 11 determined from the degree of the upward gradient of the temperature gradient may be determined by using three or more data tables. Is.

  Next, another embodiment shown in FIG. 6 will be described. In this embodiment, the description of the same configuration as that of the embodiment described above will be omitted, and only the differences will be described. An air-conditioned indoor unit 20 cools the air-conditioned space. A remote control (not shown) is installed in the air-conditioned space cooled by the indoor unit 20, and the air-conditioned space is controlled by the remote controller. When an instruction for cooling is given, driving of the compressor 4 is started, and a load operation is performed in which the load side heat exchanger 5 functions as an evaporator to cool the load side. During the load operation, the load-side heat exchanger 5 performs heat exchange between the low-temperature and low-pressure refrigerant discharged from the expansion valve 6 and the air in the air-conditioned space, and is cooled by the load-side heat exchanger 5. Is sent to the air-conditioned space and cools the air-conditioned space that is instructed by the remote control.

  Here, during the load operation, in the heat source side heat exchanger 7 of the underground heat exchanging section 2, the high temperature and high pressure refrigerant discharged from the compressor 4 and the underground heat circulation pump 11 are driven to generate the underground heat. The antifreeze circulating in the circulation circuit 10 flows oppositely to exchange heat, and the heat source side heat exchanger 7 functions as a condenser to give heat to the underground heat exchanging unit 2 side. The antifreeze is supplied to the underground heat exchanger 9 and radiated into the ground G by the underground heat exchanger 9.

Next, the action | operation at the time of load operation of other embodiment shown in FIG. 6 is demonstrated based on the flowchart shown in FIG.
When the air-conditioning space is instructed to be cooled by the remote controller, the control means 18 starts driving the compressor 4 and the underground heat circulation pump 11 to start the cooling operation as the load operation. Here, the underground heat circulation pump 11 is started to be driven at a preset initial rotation speed. In the load side heat exchanger 5, the air in the air-conditioned space and the low-temperature and low-pressure refrigerant discharged from the expansion valve 6 are subjected to heat exchange, and the cooled air in the air-conditioned space is supplied to the air-conditioned space. In addition to cooling, the heat source side heat exchanger 7 exchanges heat between the high-temperature and high-pressure refrigerant discharged from the compressor 4 and the antifreeze liquid circulated by the underground heat circulation pump 11, and the antifreeze with the heat is underground. The heat is supplied to the heat exchanger 9 and is radiated into the ground G by the underground heat exchanger 9.

  When the cooling operation is performed, the temperature of the antifreeze liquid is detected by the underground temperature sensor 12, and the control means 18 stores the temperature C of the antifreeze liquid at that time (step S14), and a predetermined time T, for example, 1 minute has elapsed. If the control means 18 determines that the predetermined time T has elapsed, the underground temperature sensor 12 detects the temperature of the antifreeze liquid, and the control means 18 detects the temperature of the antifreeze liquid at that time. D is stored (step S16), and the temperature gradient (DC) / T per predetermined time T is calculated based on the temperature C and the temperature D stored in step S14 and step S16 (step S17). .

  Subsequently, the control means 18 determines whether or not the temperature gradient calculated in step S17 is an upward gradient at (DC) / T> 0 (step S18), and the temperature gradient is an upward gradient. When the determination is made, it is determined whether or not the degree of the temperature gradient rising is equal to or greater than a preset set value γ (step S19), and the temperature gradient is determined to be greater than or equal to a preset set value γ. Then, the rotation speed of the geothermal circulation pump 11 is increased by e rotation, for example, 30 rpm, from the previous rotation speed (step S20), and the process returns to the process of the step 14, while the temperature gradient is increased in the step S18. If it is determined that the degree of the upward gradient is smaller than the preset set value γ, the rotation speed of the underground heat circulation pump 11 is increased by f rotation, for example, 10 rpm from the rotation speed until then (step S2). ), In which the process returns to the step 14. Note that the e rotation in step S20 and the f rotation in step S21 have a relationship of e rotation> f rotation.

  In step S18, if the control means 18 determines that the temperature gradient is not an upward gradient, it determines whether or not the temperature gradient calculated in step S17 is a downward gradient at (DC) / T <0. If it is determined that the temperature gradient is a downward gradient (step S22), it is determined whether or not the degree of the downward gradient of the temperature gradient is equal to or greater than a preset value δ (step S23). If it is determined that the degree is equal to or greater than the preset set value δ, the rotational speed of the underground heat circulation pump 11 is decreased by g rotation, for example, 30 rpm, from the previous rotational speed (step S24), and the process returns to step 14. On the other hand, if it is determined in step S23 that the degree of the downward gradient of the temperature gradient is smaller than the preset value δ, the rotational speed of the underground heat circulation pump 11 is changed to that. h Rotation than the rotational speed, for example, by 10rpm reduced (step S25), and in which the process returns to the step 14. Note that the g rotation in step S24 and the h rotation in step S25 have a relationship of g rotation> h rotation.

  In step S22, the control means 18 determines that the temperature gradient is not a downward gradient, that is, the temperature gradient calculated in step S17 is (DC) / T = 0 and there is no temperature gradient, or there is no temperature gradient. If it is determined that the value is small enough to be considered, the rotation speed of the underground heat circulation pump 11 is maintained (step S26), and the process returns to step S14.

  Next, the load operation shown in the flowchart of FIG. 7 will be described in detail with reference to the time chart of FIG. Here, as initial conditions, the set value γ = 2, the set value δ = 2, and the rotation speed of the geothermal circulation pump 11 at time t0 = 1000 rpm.

  First, at time t0, the control means 18 detects the temperature of the antifreeze liquid with the underground temperature sensor 12, stores the detected temperature, here 18 ° C., as the temperature C (step S14), and between the times t0 and t1. It is determined whether or not a predetermined time T, for example, 1 minute has passed (step S15). If it is determined that 1 minute has passed, the control means 18 sends the underground temperature sensor 12 at time t1. The temperature of the antifreeze is detected, and the detected temperature, here 18 ° C., is stored as the temperature D (step S16), and the temperature gradient (DC) / T = (18-18) / 1 = 0 is calculated ( In step S17), in step S18, it is determined that the temperature gradient calculated in step S17 is not an upward gradient, the process proceeds to step 22, and in step S22, the temperature gradient calculated in step S17. Is judged not to be the descending slope, the program proceeds to the step S26, to maintain the 1000rpm was speed geothermal heat circulation pump 11 so far, in which the process returns to the step S14.

  Next, at time t1, the control means 18 detects the temperature of the antifreeze with the underground temperature sensor 12, stores the detected temperature, here 18 ° C., as the temperature C (step S14), and from time t1 to t2. It is determined whether or not 1 minute has elapsed (step S15). If it is determined that 1 minute has elapsed, at time t2, the control means 18 detects the temperature of the antifreeze liquid at the underground temperature sensor 12. The detected temperature, here 20 ° C., is stored as the temperature D (step S16), and the temperature gradient (DC) / T = (20−18) / 1 = 2 is calculated (step S17). It is determined that the temperature gradient calculated in S17 is an upward gradient (step S18), and the degree of the upward gradient of the temperature gradient is 2, and it is determined that the preset set value γ = 2 or more (step S19). ), Geothermal heat The rotational speed of the ring pump 11 e rotation than the rotational speed of the far, for example, by 30rpm increased as 1030rpm in (Step S20), in which the process returns to the step 14.

  Subsequently, at time t2, the control means 18 detects the temperature of the antifreeze liquid with the underground temperature sensor 12, stores the detected temperature, here 20 ° C., as the temperature C (step S14), and from time t2 to t3. It is determined whether or not 1 minute has elapsed (step S15). If it is determined that 1 minute has elapsed, the control means 18 detects the temperature of the antifreeze liquid at the underground temperature sensor 12 at time t3. The detected temperature, here 21 ° C., is stored as the temperature D (step S16), and the temperature gradient (DC) / T = (21-20) / 1 = 1 is calculated (step S17). It is determined that the temperature gradient calculated in S17 is an ascending gradient (step S18), and the degree of the ascending gradient of the temperature gradient is 1 and is determined to be smaller than a preset set value γ = 2 (the step S19). , Underground The rotation speed of the circulation pump 11 f rotates from the rotational speed of the far, for example, by 10rpm increased as 1040Rpm (the step S21), and in which the process returns to the step 14.

  Further, during the period from time t3 to t4, the same process as during the period from time t0 to t1 is performed, and during the period from time t4 to t5, the same process as during the period from time t1 to t2 is performed. From t6 to t6, the same process as that from the time t2 to t3 is performed, and the rotation speed of the geothermal circulation pump 11 at time t6 is 1080 rpm.

  Next, at time t6, the control means 18 detects the temperature of the antifreeze liquid with the underground temperature sensor 12, stores the detected temperature, here 24 ° C., as the temperature C (step S14), and from time t6 to t7. It is determined whether or not 1 minute has elapsed (step S15). If it is determined that 1 minute has elapsed, the control means 18 detects the temperature of the antifreeze liquid at the underground temperature sensor 12 at time t7. The detected temperature, here 22 ° C. is stored as the temperature D (step S16), the temperature gradient (D−C) / T = (22−24) / 1 = −2 is calculated (the step S17), It is determined that the temperature gradient calculated in step S17 is not an upward gradient (step S18), the temperature gradient calculated in step S17 is determined to be a downward gradient (step S22), and the degree of the downward gradient of the temperature gradient is determined. However, it is determined that the set value δ = 2 or more is set in advance (step S23), and the rotational speed of the underground heat circulation pump 11 is reduced by g rotation, for example, 30 rpm, from the previous rotational speed. At 1050 rpm (step S24), the process returns to step 14.

  Subsequently, at time t7, the control means 18 detects the temperature of the antifreeze liquid with the underground temperature sensor 12, stores the detected temperature, here 22 ° C., as the temperature C (step S14), and from time t7 to time t8. It is determined whether or not 1 minute has elapsed (step S15). If it is determined that 1 minute has elapsed, at time t8, the control means 18 detects the temperature of the antifreeze using the underground temperature sensor 12. The detected temperature, here 21 ° C. is stored as the temperature D (step S16), and the temperature gradient (DC) / T = (21-22) / 1 = −1 is calculated (step S17). It is determined that the temperature gradient calculated in step S17 is not an upward gradient (step S18), the temperature gradient calculated in step S17 is determined to be a downward gradient (step S22), and the temperature gradient of the temperature gradient is determined. It is determined that the offset is 1 and is smaller than the preset setting value δ = 2 (step S23), and the rotation speed of the underground heat circulation pump 11 is reduced by h rotation, for example, 10 rpm from the previous rotation speed to 1040 rpm (Step S25), and the process returns to Step 14.

  Further, during the period from time t8 to t9, the same process as that during the period from time t0 to t1 or the period from time t3 to time t4 is performed, and the process returns to step S14.

  In the cooling operation as the load operation described above, the control means 18 obtains the temperature gradient per predetermined time based on the temperature of the antifreeze liquid detected by the underground temperature sensor 12 in the step S14 to the step S17, If it is determined in step S18 that the calculated temperature gradient is an ascending gradient, the rotational speed of the underground heat circulation pump 11 is increased from the previous rotational speed, and in step S22, the step S17 is performed. When it is determined that the temperature gradient calculated in step 1 is a downward gradient, the rotational speed of the underground heat circulation pump 11 is decreased from the rotational speed up to that time, so that the magnitude of the load that changes from time to time can be determined. When the temperature gradient is ascending, that is, when the cooling operation load increases, the underground heat circulation pump is monitored and grasped by the sensor 12. Increase the number of revolutions of 1 above the number of revolutions up to that point to eliminate the temperature gradient, and to achieve the minimum circulation flow rate to secure the necessary heat dissipation for the load The rotation speed of the pump 11 can be set, and when the temperature gradient is a downward gradient, that is, when the load of the load operation is reduced, the rotation speed of the underground heat circulation pump 11 is set to the rotation speed up to that time. It is possible to set the rotation speed of the underground heat circulation pump 11 so that the minimum circulation flow rate is obtained in order to reduce the temperature gradient and to eliminate the temperature gradient and to secure the necessary heat radiation amount for the load. Therefore, the heat can be optimally radiated without excessively radiating heat and without being radiated, and the efficiency of the overall underground heat pump device can be improved.

  If the control means 18 determines that the temperature gradient calculated in step S17 is an upward gradient, whether or not the degree of the temperature gradient is equal to or greater than a preset set value γ in step S19. Therefore, when the degree of the upward gradient of the temperature gradient is equal to or greater than the set value γ, the amount of increase in the rotation speed of the geothermal circulation pump 11 is increased compared to the case where the temperature gradient is smaller than the set value γ. Here, the magnitude of the upward gradient of the temperature gradient means how far it is from the circulation flow rate for securing the necessary heat dissipation amount for the load, that is, the insufficient heat dissipation amount, When the heat dissipation amount is largely insufficient, the rotational speed of the underground heat circulation pump 11 is greatly increased as in step S20, and when the heat dissipation amount is slightly insufficient, the ground temperature is increased as in step S21. The rotational speed of the intermediate heat circulation pump 11 is increased by a small amount. Therefore, the control means 18 increases the amount of increase in the number of rotations of the underground heat circulation pump 11 as the degree of the upward gradient of the temperature gradient is increased, so that the circulation flow rate for securing a necessary heat radiation amount for the load is obtained. Thus, the number of rotations of the underground heat circulation pump 11 can be brought close quickly and accurately, whereby optimum heat radiation can be achieved, and the efficiency of the overall underground heat pump device can be improved.

  If the control means 18 determines that the temperature gradient calculated in step S17 is a downward gradient, whether or not the downward gradient of the temperature gradient is greater than or equal to a preset value δ in step S23. If the degree of the downward gradient of the temperature gradient is equal to or greater than the set value δ, the amount of decrease in the rotation speed of the underground heat circulation pump 11 is made larger than when the temperature gradient is smaller than the set value δ. Here, the magnitude of the downward gradient of the temperature gradient means how far away from the circulating flow rate to secure the necessary heat dissipation amount for the load, that is, the excessive amount of heat dissipation amount, If the amount of heat release is too large, the rotational speed of the underground heat circulation pump 11 is greatly reduced as in step S24, and if the amount of heat release is slightly higher, the amount of heat released from the underground heat circulation pump 11 as in step S25. The rotational speed is reduced by a small amount. Therefore, the control means 18 increases the amount of decrease in the number of rotations of the geothermal circulation pump 11 as the degree of the downward gradient of the temperature gradient increases, and thereby the circulation flow rate for ensuring the necessary heat dissipation amount for the load Thus, the number of revolutions of the underground heat circulation pump 11 can be brought close quickly and accurately, whereby optimum heat radiation can be performed, and the efficiency of the overall underground heat pump device can be improved.

  In the other embodiment described above, the air-conditioning space is cooled by directly exchanging heat between the refrigerant discharged from the expansion valve 6 in the load-side heat exchanger 5 of the indoor unit 20 and the air in the air-conditioned space. In the operation, the control of the present invention is applied. However, the present invention is not limited to the other embodiments described above, and the load heat exchanging unit 3 is of a heat medium circulation type. Heat exchange is performed between the refrigerant discharged from the expansion valve 6 in the side heat exchanger 5 and the heat medium on the load heat exchanging unit 3 side, the heat medium on the load heat exchanging unit 3 side is circulated, and the space to be air-conditioned by the load terminal The control of the present invention may be applied to the cooling operation that cools the interior of the room, and various modifications are possible without departing from the scope of the present invention. Absent.

  In the other embodiments described above, the plurality of underground heat exchangers 9 embedded in the ground are connected in parallel to each other, but the plurality of underground heat exchangers 9 embedded in the ground are mutually connected. It may be connected in series.

  In the other embodiments described above, the magnitude of the load that changes from moment to moment is monitored and grasped by the underground temperature sensor 12, but even if the magnitude of the load does not change, the flow of groundwater, The amount of heat that can be dissipated into the ground changes depending on factors such as the operation status of the intermediate heat pump device, and the temperature of the antifreeze liquid detected by the underground temperature sensor 12 may change. If the temperature gradient is ascending, that is, if the amount of heat that can be dissipated into the ground is reduced, the rotational speed of the underground heat circulation pump 11 is determined. The number of rotations of the underground heat circulation pump 11 is increased so as to eliminate the temperature gradient, and the minimum circulation flow rate for securing a necessary heat radiation amount for the load. Can also be set When the gradient is downward, that is, when the amount of heat that can be dissipated into the ground increases, the rotational speed of the underground heat circulation pump 11 is decreased from the rotational speed up to that point, in the direction of eliminating the temperature gradient, In addition, the rotation speed of the underground heat circulation pump 11 can be set so that the minimum circulation flow rate for securing the necessary heat radiation amount for the load can be set, and it is possible to radiate heat without excessive heat radiation. It is possible to radiate heat optimally and improve the efficiency of a comprehensive underground heat pump device.

  In the other embodiment described above, the control means 18 obtains and calculates the temperature gradient per predetermined time based on the temperature of the antifreeze liquid detected by the underground temperature sensor 12 in Step S14 to Step S17. Although the increase / decrease control of the rotation speed of the underground heat circulation pump 11 is performed by the temperature gradient, the temperature of the antifreeze liquid detected by the underground return temperature sensor 13 is also changed with respect to the load and the underground state that change every moment. Since the tendency similar to the temperature of the antifreeze liquid detected by the underground going-out temperature sensor 12 is shown, the control means 18 determines the predetermined temperature based on the temperature of the antifreeze liquid detected by the underground return temperature sensor 13 from the step S14 to the step S17. The temperature gradient per hour may be obtained, and the increase / decrease control of the rotation speed of the underground heat circulation pump 11 may be performed based on the calculated temperature gradient. The underground return temperature sensor 13 monitors and grasps the magnitude of the load to be converted and the underground condition, and when the temperature gradient is ascending, that is, the load of the load operation increases or the amount of heat that can be radiated into the ground is In the case of a decrease, the number of rotations of the underground heat circulation pump 11 is increased more than the number of rotations up to that point, so that the minimum amount of heat radiation required for the load is ensured in the direction of eliminating the temperature gradient. The number of rotations of the underground heat circulation pump 11 can be set so that the circulation flow rate becomes the same, and when the temperature gradient is a downward gradient, that is, the load of the load operation is reduced or the amount of heat that can be radiated into the ground Is increased, the number of rotations of the underground heat circulation pump 11 is decreased from the number of rotations up to that point, so that the minimum amount of heat radiation required for the load is ensured in the direction of eliminating the temperature gradient. So that the circulation flow is limited The number of rotations of the intermediate heat circulation pump 11 can be set, and heat can be optimally radiated without radiating too much heat and without radiating heat, thereby improving the efficiency of the overall geothermal heat pump device. It is something that can be done.

  Further, in the other embodiment described above, in the step S19, the determination of the degree of the temperature gradient is greater than or less than a preset set value γ, and the underground heat circulation is performed. Although the increase amount of the rotation speed of the pump 11 is determined, if the increase amount of the rotation speed of the geothermal circulation pump 11 is increased as the degree of the upward gradient of the temperature gradient is increased, for example, When the degree of the temperature gradient is 1, the rotation speed of the geothermal circulation pump 11 is increased by 10 rpm. When the degree of the temperature gradient is 2, the rotation of the geothermal circulation pump 11 is increased. When the number is increased by 30 rpm and the degree of the temperature gradient is 3, the geothermal heat determined from the degree of the temperature gradient is increased, for example, the rotational speed of the geothermal circulation pump 11 is increased by 50 rpm. Of the circulation pump 11 The increase in the number of rotations may be determined by using three or more data tables. Similarly, in step S23, the determination of the degree of the downward gradient of the temperature gradient is greater than or equal to a preset set value δ. The amount of decrease in the number of rotations of the geothermal circulation pump 11 is determined by two choices of whether the geothermal circulation pump 11 is smaller or smaller. As long as the amount of decrease in the rotational speed is increased, the amount of decrease in the rotational speed of the geothermal circulation pump 11 determined from the degree of the downward gradient of the temperature gradient can be determined by using three or more data tables. You can do it.

4 Compressor 5 Load side heat exchanger 6 Pressure reducing means (expansion valve)
7 Heat source side heat exchanger 8 Heat pump circuit 9 Geothermal heat exchanger 10 Geothermal circulation circuit 11 Geothermal circulation pump 12 Underground temperature detection means (underground temperature sensor)
13 Underground return temperature detection means (underground return temperature sensor)
18 Control means

Claims (7)

A heat pump circuit in which a compressor, a load-side heat exchanger, a pressure reducing means, and a heat source-side heat exchanger are connected in a ring shape with refrigerant piping, and a plurality of underground heat exchangers embedded in the ground and connected in parallel or in series with each other A ground heat circulation circuit that circulates between the ground heat exchanger and the heat source side heat exchanger, a ground heat circulation pump that circulates a heat medium in the ground heat circulation circuit, and The underground forward temperature detecting means for detecting the temperature of the heat medium flowing into the underground heat exchanger, the underground return temperature detecting means for detecting the temperature of the heat medium flowing out of the underground heat exchanger, and the operation thereof. Control means for controlling, collecting ground heat by the underground heat exchanger, causing the heat source side heat exchanger to function as an evaporator, and causing the load side heat exchanger to function as a condenser to load In the geothermal heat pump device that performs load operation to heat the side, During the load operation, the control means rotates the underground heat circulation pump when the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is a downward gradient. When the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is an upward gradient, the rotational speed of the underground heat circulation pump is set to Further, the control means increases the amount of increase in the number of rotations of the geothermal circulation pump as the degree of the downward gradient of the temperature gradient is larger. apparatus. 2. The geothermal heat pump device according to claim 1, wherein the control means increases the amount of decrease in the rotation speed of the geothermal circulation pump as the degree of the upward gradient of the temperature gradient increases. A heat pump circuit in which a compressor, a load-side heat exchanger, a pressure reducing means, and a heat source-side heat exchanger are connected in a ring shape with refrigerant piping, and a plurality of underground heat exchangers embedded in the ground and connected in parallel or in series with each other A ground heat circulation circuit that circulates between the ground heat exchanger and the heat source side heat exchanger, a ground heat circulation pump that circulates a heat medium in the ground heat circulation circuit, and The underground forward temperature detecting means for detecting the temperature of the heat medium flowing into the underground heat exchanger, the underground return temperature detecting means for detecting the temperature of the heat medium flowing out of the underground heat exchanger, and the operation thereof. Control means for controlling, collecting ground heat by the underground heat exchanger, causing the heat source side heat exchanger to function as an evaporator, and causing the load side heat exchanger to function as a condenser to load In the geothermal heat pump device that performs load operation to heat the side, During the load operation, the control means rotates the underground heat circulation pump when the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is a downward gradient. When the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is an upward gradient, the rotational speed of the underground heat circulation pump is set to to reduce, further, the control means, underground heat characterized in that the larger the degree of the upward gradient of the temperature gradient so as to increase the decrease rotational speed of said geothermal heat circulation pump Heat pump device.   During the load operation, if the heat medium temperature detected by the underground temperature detection means becomes lower than the lower limit temperature set in advance based on the concentration of the heat medium, the underground heat circulation pump The geothermal heat pump device according to any one of claims 1 to 3, wherein the number of rotations is increased. A heat pump circuit in which a compressor, a load-side heat exchanger, a pressure reducing means, and a heat source-side heat exchanger are connected in a ring shape with refrigerant piping, and a plurality of underground heat exchangers embedded in the ground and connected in parallel or in series with each other A ground heat circulation circuit that circulates between the ground heat exchanger and the heat source side heat exchanger, a ground heat circulation pump that circulates a heat medium in the ground heat circulation circuit, and The underground forward temperature detecting means for detecting the temperature of the heat medium flowing into the underground heat exchanger, the underground return temperature detecting means for detecting the temperature of the heat medium flowing out of the underground heat exchanger, and the operation thereof. Control means for controlling, heat is radiated into the ground by the underground heat exchanger, the heat source side heat exchanger functions as a condenser, and the load side heat exchanger functions as an evaporator to load side In geothermal heat pump equipment that performs load operation to cool During the load operation, the control means, when the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is an upward gradient, the rotation speed of the underground heat circulation pump When the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is a downward gradient, the rotational speed of the underground heat circulation pump is decreased. Furthermore, the control means increases the amount of increase in the rotation speed of the geothermal circulation pump as the degree of the upward gradient of the temperature gradient increases. . 6. The geothermal heat pump device according to claim 5, wherein the control means increases the amount of decrease in the rotational speed of the geothermal circulation pump as the degree of descending temperature gradient increases. A heat pump circuit in which a compressor, a load-side heat exchanger, a pressure reducing means, and a heat source-side heat exchanger are connected in a ring shape with refrigerant piping, and a plurality of underground heat exchangers embedded in the ground and connected in parallel or in series with each other A ground heat circulation circuit that circulates between the ground heat exchanger and the heat source side heat exchanger, a ground heat circulation pump that circulates a heat medium in the ground heat circulation circuit, and The underground forward temperature detecting means for detecting the temperature of the heat medium flowing into the underground heat exchanger, the underground return temperature detecting means for detecting the temperature of the heat medium flowing out of the underground heat exchanger, and the operation thereof. Control means for controlling, heat is radiated into the ground by the underground heat exchanger, the heat source side heat exchanger functions as a condenser, and the load side heat exchanger functions as an evaporator to load side In geothermal heat pump equipment that performs load operation to cool During the load operation, the control means, when the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is an upward gradient, the rotation speed of the underground heat circulation pump When the temperature gradient of the heating medium temperature detected by the underground return temperature detecting means or the underground return temperature detecting means is a downward gradient, the rotational speed of the underground heat circulation pump is decreased. so as to further the control means, geothermal heat pump you characterized in that so as to increase the amount of reduction of the rotational speed of the underground heat circulation pump larger the degree of downward slope of the temperature gradient apparatus.

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