Method for controlling heat exchange device of water-cooled heat pump

Abstract

To effectively use heat quantity of a heat source and reduce electric power consumption during an operation of a water-cooling type heat pump in a control method for a heat exchange device for the water-cooling type heat pump.SOLUTION: First control and second control are included. A flow passage 3 of a heat exchange device 1 includes a heating medium liquid circulation flow passage 7 having a first heat exchange part 6 that exchanges heat with a second heat exchange part 5 on a load side. In the heating medium liquid circulation flow passage 7, a constant amount of first heating medium liquid 11 circulates. Second heating medium liquid 13 is supplied from a heat source 15 on an inlet end side 12 of the first heat exchange part 6, and the same amount of the first heating medium liquid 11 as that of the supply amount is discharged on an outlet end 16 side of the first heat exchange part 6. The first control is control for preserving the heat quantity of the heat source as much as possible and the second control is control for effectively using surplus heat quantity of the heat source. Momentary heat quantity held by the heat source is grasped, and the second control is prioritized. The second control is changed to the first control so as not to deplete the heat source.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for controlling a heat exchanger of a water-cooled heat pump, which can effectively utilize the heat quantity of a heat source such as geothermal heat and reduce the amount of power consumption associated with the operation of the heat pump. [Background technology]

[0002] As an example of a heat exchanger for a water-cooled heat pump that uses geothermal heat as a heat source, one disclosed in Patent Document 1 has been proposed. The heat exchanger had a configuration in which a first heat transfer liquid was circulated through a heat transfer liquid circulation flow path having a first heat exchange section that performs heat exchange with a second heat exchange section, and a necessary amount of the second heat transfer liquid capable of imparting the amount of heat required by the first heat exchange section was supplied to the heat transfer liquid circulation flow path from a heat source that holds a second heat transfer liquid having a temperature difference from that of the first heat transfer liquid, thereby performing heat exchange between the first heat exchange section and the second heat exchange section.

[0003] As described above, this heat exchange device was configured to perform heat exchange between the first heat exchange section and the second heat exchange section by supplying the second heat transfer liquid in an amount necessary to provide the amount of heat required by the first heat exchange section to the heat transfer liquid circulation path, thereby having the advantage of minimizing heat utilization in the heat source, thereby making effective use of the heat amount of the heat source.

[0004] However, when a water-cooled heat pump device using the heat exchanger of the above configuration is used, the efficiency of the heat pump is sacrificed.

[0005] To explain this point with a concrete example, in the case of a water-cooled heat pump device using the heat exchanger of the above configuration, for example, a water-cooled heat pump air conditioner, when the water-cooled heat pump air conditioner has a plurality of indoor units (for example, 10 units) connected to one outdoor unit, the heat amount of the heat source is set assuming that all of the indoor units are in operation. If the number of indoor units in operation is artificially limited (for example, limited to 2 to 3 units) and the air conditioner is operated, the heat amount of the heat source will be excessively conserved. As a result, although there is surplus heat that can be used by the heat pump, it is not used, which increases the compression work of the heat pump compressor, which puts a load on the heat pump and sacrifices the efficiency of the heat pump. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-52845 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention was developed in consideration of the above-mentioned problems in the conventional technology, and aims to provide a control method for a heat exchanger of a water-cooled heat pump that can effectively utilize the heat of the heat source without depleting it, and that is economical in that it can reduce the amount of power consumed by operating the heat pump. [Means for solving the problem]

[0008] In order to solve the above problems, a control method for a heat exchanger of a water-cooled heat pump according to the present invention is characterized in that it satisfies the following requirements. (1) A control method for a heat exchanger of a water-cooled heat pump that controls the temperature of a load side (41) to a set temperature, the method including a first control and a second control. (2) The heat exchange device is provided with a flow path (3) through which a heat transfer liquid (2) flows, and the flow path (3) The second The water-cooled heat pump (8) is provided with a heat transfer fluid circulation flow path (7) having a first heat exchange section (6) for performing heat exchange between the first heat exchange section (6) and the heat transfer fluid of the water-cooled heat pump (8). A heat pump heat medium of the water-cooled heat pump (8) flows through the second heat exchange section (5). A constant amount of a first heat transfer fluid (11) is circulated through the heat transfer fluid circulation flow path (7). At the side where an inlet end (12) of the first heat exchange section (6) is present, a second heat transfer fluid (13) having a temperature different from that of the first heat transfer fluid (11) is supplied from a heat source (15) having the second heat transfer fluid (13). A temperature detector (17) is provided for detecting the temperature of the first heat transfer liquid (11) at the outlet end (16) of the heat transfer device, and the heat transfer device is configured to discharge, on the side where the outlet end (16) is present, an amount of the first heat transfer liquid (11) equal to the amount of the second heat transfer liquid (13) supplied thereto. (3) The first control is to control the supply of a necessary amount of the second heat transfer liquid (13) from the heat source (15) on the side where the inlet end (12) of the first heat exchange section (6) is located, so that the detected temperature of the first heat transfer liquid (11) by the temperature detector (17) at the outlet end (16) of the first heat exchange section is maintained at a required set temperature. (4) The second control is a control is performed so that only the second heat transfer liquid (13) of the heat source (15) flows through the heat transfer liquid circulation path (7) regardless of the temperature of the first heat transfer liquid (11) detected by the temperature detector (17); Alternatively, a heat increase control is performed by adding a required amount of the second heat transfer fluid (13) of the heat source (15) to the required amount. The required amount is set so that the temperature detected by the temperature detector becomes a set temperature within a range in which the efficiency of the water-cooled heat pump does not decrease. (5) The second control is executed when both the first and second conditions below are satisfied, and when either of the conditions is no longer satisfied, the second control is changed to the first control. First condition: A required set ratio of heat quantity set within a range of 10 to 90% of the initial heat quantity of the heat source remains in the heat source. Here, the initial heat quantity refers to the maximum set heat quantity of the heat source. This maximum set heat quantity is set as required for each heat source. The second condition: The output of the water-cooled heat pump must not fall below the required set output, which is set at 50% or less of its maximum output. (6) When a state in which both the first condition and the second condition are satisfied occurs while the first control is being executed, the first control is changed to the second control. Effect of the Invention

[0009] The control method for a heat exchanger of a water-cooled heat pump according to the present invention can effectively utilize the heat quantity of the heat source without depleting the heat source, and can reduce the power consumption associated with the operation of the heat pump, thereby making electricity bills cheaper. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is an explanatory diagram illustrating one embodiment of a control method for a heat exchanger of a water-cooled heat pump according to the present invention. [Diagram 2] FIG. 11 is an explanatory diagram illustrating another embodiment of the control method for the heat exchanger of the water-cooled heat pump according to the present invention. [Diagram 3] FIG. 11 is an explanatory diagram illustrating another embodiment of the control method for the heat exchanger of the water-cooled heat pump according to the present invention. [Figure 4] FIG. 13 is an explanatory diagram showing a configuration in which a mixing three-way valve is replaced with two flow rate regulating two-way valves. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0011] 1-2, the control method for the heat exchanger of the water-cooled heat pump according to the present invention (hereinafter, also referred to as the control method) is a control method for the heat exchanger of the water-cooled heat pump that controls the temperature on the load side to a set temperature, and includes a first control and a second control. Here, the first control is a control that minimizes the heat utilization in the heat source to conserve the heat amount of the heat source as much as possible, and the second control is a control that effectively utilizes the surplus heat amount of the heat source without depleting the heat source.

[0012] As shown in Figs. 1 and 2, the heat exchange device 1 is provided with a flow path 3 through which a heat transfer liquid 2 flows, and the flow path 3 includes a heat transfer liquid circulation flow path 7 having a first heat exchange section 6 that exchanges heat with a second heat exchange section 5 on the load side, and a heat pump heat medium 9 of the water-cooled heat pump (hereinafter simply referred to as a heat pump, which is inverter controlled) 8 flows through the second heat exchange section 5. A constant amount of a first heat transfer liquid 11 is circulated through the heat transfer liquid circulation flow path 7, and the second heat transfer liquid 13 having a temperature difference from that of the first heat transfer liquid 11 is supplied from a heat source 15 that holds a second heat transfer liquid 13 on the side where an inlet end 12 of the first heat exchange section 6 exists, and a temperature detector 17 that detects the temperature of the first heat transfer liquid 11 at the outlet end 16 of the first heat exchange section 6 is provided. Also, the side where the outlet end 16 exists is configured to discharge the first heat transfer liquid 11 in the same amount as the second heat transfer liquid 13 supplied.

[0013] In this embodiment, the heat source 15 and the heat transfer liquid circulation flow path 7 are connected by a supply pipe 19. The supply pipe 19 is connected to the side where the inlet end 12 of the first heat exchange section 6 exists, and a discharge pipe 22 is connected to the side where the outlet end 16 of the first heat exchange section 6 exists (FIGS. 1(A) and 2). Then, a necessary amount of the second heat transfer liquid 13 capable of imparting the amount of heat required by the first heat exchange section 6 can be supplied to the side where the inlet end 12 exists through the supply pipe 19 so that the detected temperature of the first heat transfer liquid 11 at the outlet end 16 maintains a required set temperature. Also, the first heat transfer liquid 11 is discharged from the discharge pipe 22 in an amount equal to the amount of the second heat transfer liquid 13 supplied.

[0014] Here, the first heat transfer liquid 11 refers to the heat transfer liquid among the heat transfer liquid 2 that circulates through the heat transfer liquid circulation flow path 7, and the second heat transfer liquid 13 refers to the heat transfer liquid among the heat transfer liquid 2 that is supplied to the heat transfer liquid circulation flow path 7 from the heat source 15.

[0015] As shown in Fig. 1, a pump (e.g., inverter-controlled) 23 is attached to the heat transfer liquid circulation flow path 7 in order to circulate the first heat transfer liquid 11 through the heat transfer liquid circulation flow path 7 and to discharge the first heat transfer liquid 11 in an amount equal to the second heat transfer liquid 13 supplied. A three-way mixing valve 30 having first, second, and third connection ports 26, 27, and 29 is interposed at a connection portion 25 of the supply pipe 19 to the heat transfer liquid circulation flow path 7, and the pump 23 is interposed between the three-way mixing valve 30 and the inlet end 12. In this embodiment, an electrically controlled three-way mixing valve is used as the three-way mixing valve 30. As shown in Fig. 1, a flow rate control valve 31 is interposed between the pump 23 and the inlet end 12.

[0016] In the heat exchange device 1 having such a configuration, the first control is to control the supply of the second heat transfer liquid 13 from the heat source 15 in an amount sufficient to provide the amount of heat required by the first heat exchange section 6, so that the detected temperature of the first heat transfer liquid 11 by the temperature detector 17 at the outlet end 16 of the first heat exchange section 6 on the side where the inlet end 12 of the first heat exchange section 6 is located is maintained at the required set temperature.

[0017] The second control is a control for causing only the second heat transfer liquid 13 of the heat source 15 to flow through the heat transfer liquid circulation flow path 7, regardless of the temperature of the first heat transfer liquid 11 detected by the temperature detector 17. Alternatively, a heat increase control is performed for adding a required amount of the second heat transfer liquid 13 of the heat source 15 to the required amount.

[0018] The second control is executed when both the first and second conditions below are satisfied, and when either of the conditions is no longer satisfied, the second control is changed to the first control. First condition: A required set ratio of heat quantity set within a range of 10 to 90% of the initial heat quantity of the heat source 15 remains in the heat source 15. The initial heat quantity here refers to the maximum set heat quantity of the heat source. This maximum set heat quantity is set as required for each heat source. The second condition: The output of the heat pump does not fall below the required set output, which is set at 50% or less of its maximum output.

[0019] Hereinafter, the heat exchanger 1 will be specifically described by taking as an example a case where the heat exchanger 1 is used to configure a water-cooled heat pump cooling and heating system (hereinafter also referred to as a cooling and heating system) 32.

[0020] The air conditioner 32 uses geothermal heat, which maintains a nearly constant temperature throughout the year (for example, about 15°C in Fukui Prefecture), as a heat source. For the sake of convenience, the following description specifies the annual average temperature of geothermal heat as 15°C.

[0021] The heat source 15 constituting the heat exchange device 1 is configured, in this embodiment, using, for example, a heat exchange tank 33 shown in FIG. 1. In this embodiment, the heat exchange tank 33 is formed by excavating the ground to a required depth (for example, excavating to a depth of 50 to 100 m) and covering the inner wall of the hole with a bottomed cylindrical casing, and the heat transfer liquid 2 is stored in the heat exchange tank 33. The heat transfer liquid 2 is configured to absorb geothermal heat through the wall 35 of the heat exchange tank 33, or to release the heat held by the heat transfer liquid 2 to the ground through the wall 35. In this embodiment, the heat exchange tank 33 is configured as a sealed water tank 37 with the upper open part closed by a lid member 36, as shown in FIG. 1.

[0022] The scale of the heat source 15 is set in consideration of the maximum load on the load side. When the heat amount held by the heat source 15 is used for 12 hours, for example, from 7:00 a.m. to 7:00 p.m., during the 12-hour period when the heat source 15 is not used, geothermal heat is accumulated in the heat transfer liquid 2 in the heat exchange reservoir 33, and the temperature of the heat transfer liquid 2 in the heat exchange reservoir 33 becomes the same as the underground temperature. The heat amount in the heat exchange reservoir 33 at this time is an example of the initial heat amount.

[0023] The first heat exchange section 6 and the second heat exchange section 5 are incorporated into a first heat exchanger 39, which is, for example, a plate-type heat exchanger having good thermal efficiency. Thus, in the first heat exchanger 39, heat exchange is performed between the first heat transfer liquid 11 flowing through the first heat exchange section 6 and the heat pump heat medium 40 flowing through the second heat exchange section 5, as the first heat transfer liquid 11 circulates through the heat transfer liquid circulation passage 7.

[0024] When the load side 41 is heated by the air conditioner 32, as shown in FIG. 1, the heat transfer liquid 2, which is obtained by absorbing geothermal heat through the wall 35 in the heat exchange storage tank 33, is transported to the first heat exchange section 6 by driving the pump 23. In the first heat exchanger 39, heat is dissipated from the heat transfer liquid 2 in the first heat exchange section 6 to the low-temperature and low-pressure heat pump heat medium 40 in the second heat exchange section 5 that has passed through an expansion valve 42, thereby heating the heat pump heat medium 40. The heat pump heat medium 40 that has left the second heat exchange section 5 is compressed and heated by a compressor 43, and then expanded by a second heat exchanger 46 provided on the load side 41, where heat is exchanged between the heat pump heat medium 40 and the air on the load side 41, and heat is dissipated to the load side 41 to heat the load side.

[0025] Conversely, when cooling the load side 41 in summer, as shown in Fig. 2, the heat of the air on the load side 41 is absorbed by the heat pump heat medium 40 in the second heat exchanger 46. After being compressed by the compressor 43, the heat pump heat medium 40 is condensed in the first heat exchanger 39 and dissipates heat to the first heat transfer liquid 11 in the first heat exchange section 6. The first heat transfer liquid 11 that has absorbed heat is transported to the heat exchange reservoir 33 by driving the pump 23. In the heat exchange reservoir 33, the heat held by the heat transfer liquid 2 is dissipated through the wall portion 35 to the ground 47 around the heat exchange reservoir 33.

[0026] 1(A)(B), the three-way mixing valve 30 is interposed in the connection portion 25 of the supply pipe 19 to the heat transfer liquid circulation passage 7, and has the first, second and third connection ports 26, 27 and 29. The first connection port 26 is connected to an upstream end 50 of the heat transfer liquid circulation passage 7 as viewed in the circulation direction F1, the second connection port 27 is connected to a downstream end 51 as viewed in the circulation direction F1, and the third connection port 29 is connected to a supply end 52 of the supply pipe 19. The second connection port 27 is set to a required opening degree, such as being fully opened, and the opening degree of the first connection port 26 (including the case where it is fully closed) and the opening degree of the third connection port 29 are electrically controlled by a valve body (not shown) built into the three-way mixing valve 30.

[0027] In the first control, the total amount of the inflow of the first heat transfer liquid 11 from the first connection port 26 into the mixing three-way valve 30 and the inflow of the second heat transfer liquid 13 from the third connection port 29 into the mixing three-way valve 30, which are obtained by driving the pump 23, is controlled to be equal to the outflow amount from the second connection port 27 to the heat transfer liquid circulation flow path 10 (set to 20 L / min by the flow rate control valve 31 in this embodiment, as described later). In the mixing three-way valve 30, the first heat transfer liquid 11 and the second heat transfer liquid 13 are mixed to become a mixed heat transfer liquid, and the mixed heat transfer liquid is discharged from the second connection port 27 to the heat transfer liquid circulation flow path 7. The opening degree of the third connection port 29 is electrically controlled so that the required amount of the second heat transfer liquid 13 flows into the mixing three-way valve 30.

[0028] In the second control, the first connection port 26 is fully closed and at the same time the third connection port 29 is fully opened, so that only the second heat transfer liquid 13 flows into the first heat exchange section 6.

[0029] In this embodiment, the flow rate control valve 31 is used to adjust the supply rate of the pump 23 to the flow rate required by the first heat exchange section 6, and in this embodiment, it is adjusted to 20 L / min.

[0030] As shown in FIG. 1, the upper end 56 of a first pipe 55 is connected to the connection end 53 of the supply pipe 19 opposite to the supply end 52 via a first three-way valve 57 for switching the flow path. The first pipe 55 extends in the vertical direction, and its lower end opening 57 is connected to the upper end 60 of the heat exchange reservoir 33. The upper end 65 of a second pipe 63 is connected to the connection end 62 of the discharge pipe 22 opposite to the connection end 61 with respect to the heat transfer liquid circulation flow path 7 via a second three-way valve 66 for switching the flow path. The second pipe 63 extends downward along the outer surface 67 of the heat exchange reservoir 33, and its lower end opening 69 is connected to the lower end 70 of the heat exchange reservoir 33. The remaining connection port 71 of the second three-way switching valve 66 and an upper portion 72 of the first pipe 55 are connected by a first switching connecting pipe 73. The remaining connection port 71 of the first three-way switching valve 57 and an upper portion 75 of the second pipe 63 are connected by a second switching connecting pipe 76.

[0031] By the flow path switching action of the first and second three-way valves 57, 66, the flow direction of the heat transfer liquid 2 flowing through the first pipe body 55 and the second pipe body 63 can be switched as shown by arrows in Figures 1 and 2 depending on whether the air conditioning and heating device 32 is used for heating or cooling.

[0032] This switching is performed in consideration of the fact that the temperature of the heat transfer liquid 2 contained in the heat exchange reservoir 33 is high in the upper portion 77 and low in the lower portion 79. When the air conditioner 32 is used for heating, as shown in Fig. 1, the high-temperature heat transfer liquid 2 in the upper portion 77 sucked into the lower end opening 59 of the first pipe 55 is supplied to the heat transfer liquid circulation flow path 7 from the supply end 52 as the second heat transfer liquid 13 by this flow path switching. At the same time, the low-temperature first heat transfer liquid 11 discharged from the discharge pipe 22 is discharged from the lower end opening 69 of the second pipe 63 in the lower portion 79.

[0033] Conversely, when the air-conditioning device 32 is used for cooling, as shown in FIG. 2, the low-temperature heat transfer liquid 2 in the lower portion 79 is sucked in through the lower end opening 69 of the second pipe 63 and supplied to the supply pipe 19, and the high-temperature first heat transfer liquid 11 discharged from the discharge pipe 22 is discharged from the lower end 60 of the first pipe 55 through the lower end opening 59.

[0034] Here, the first control and the second control will be described in more detail.

[0035] First, the first control will be described. As described above, the first control is a control for supplying a necessary amount of the second heat transfer liquid 13 from the heat source 15 to provide the amount of heat required by the first heat exchange section 6, so that the temperature of the first heat transfer liquid 11 detected by the temperature detector 17 at the outlet end 16 of the first heat exchange section 6 on the side where the inlet end 12 of the first heat exchange section 6 exists is maintained at a required set temperature.

[0036] When the second heat transfer liquid 13 is supplied to the heat transfer liquid circulation flow path 7, the first heat transfer liquid 11 in an amount equal to the amount of the supplied second heat transfer liquid 13 is returned from the heat transfer liquid circulation flow path 7 to the heat exchange reservoir 33 via the discharge pipe 22 by the heat transfer liquid pushing action of the pump 23. As shown in FIG. 1, the supply of the second heat transfer liquid 13 by the drive of the pump 23 is smoothly performed by the increase in pressure in the sealed water tank 37 accompanying the flow of the first heat transfer liquid 11 into the heat exchange reservoir 33, because the heat exchange reservoir 33 is configured as a sealed water tank 37.

[0037] The second heat transfer liquid 13 supplied by operation of the pump 23 is mixed by the mixing three-way valve 30 with the first heat transfer liquid 11 flowing into the mixing three-way valve 30 from the first connection port 26 (FIG. 1(B)), and 20 L / min of the mixed heat transfer liquid is supplied to the heat transfer liquid circulation flow path 7 from the second connection port 27 (FIG. 1(B)).

[0038] The required amount of the second heat transfer fluid 13 is set so that the detected temperature of the first heat transfer fluid 11 at the outlet end 16 of the first heat exchange section 6 remains at a required set temperature. In other words, the required amount is set so that the first heat exchange section 6 can provide the amount of heat required from time to time.

[0039] In order to set this required amount, the three-way mixing valve 30 is electrically controlled by a detection signal from a temperature detector 17 provided at the outlet end 16. For example, when the air conditioner 32 is used for heating, if the predetermined circulation amount required by the air conditioner 32 is 20 L / min and the required set temperature of the first heat transfer liquid 11 at the outlet end 16 is 2°C, the required amount of the second heat transfer liquid 13 is supplied from the inlet end 12 to the heat transfer liquid circulation flow path 7 so that the detected temperature of the first heat transfer liquid 11 at the outlet end 16 maintains the required set temperature of 2°C.

[0040] Now, suppose that the required liquid temperature at the inlet end 12 of the first heat exchange section 6 required to maintain the required set temperature of 2°C at the outlet end 16 during normal operation of the air conditioner 32 is 7°C. To achieve this, the required amount of heat transfer liquid 2 in the heat exchange reservoir 33, which has been heated by geothermal heat and has a temperature of 15°C, is supplied as the second heat transfer liquid 13 to the first heat transfer liquid 11 circulating through the heat transfer liquid circulation flow path 7. This ensures the required liquid temperature of 7°C at the inlet end 12.

[0041] Thereafter, when the load side 41 warms up to a certain extent, the amount of heat exchange in the first heat exchange section 6 may be reduced. At that time, if the required liquid temperature at the inlet end 12 required to maintain the detected temperature of the first heat transfer liquid 11 at the outlet end 16 at the required set temperature of 2°C is 5°C, the required amount of the second heat transfer liquid 13 may be reduced compared to the initial amount. This required amount is automatically set by electrically controlling the mixing three-way valve 30 in response to a temperature detection signal from a temperature detector 17 provided at the outlet end 16. The electrically controlled mixing three-way valve 30 means that the opening degree of the first connection port 26 and the opening degree of the third connection port 27 are electrically controlled by the valve body, as described above. Thereafter, as the load side 41 approaches the set temperature, the required amount further decreases, but this required amount is similarly set to the required amount by the electrically controlled mixing three-way valve 30.

[0042] When the air conditioner 32 is used for cooling, if the predetermined circulation amount required by the air conditioner 32 is 20 L / min and the required set temperature of the first heat transfer liquid 11 at the outlet end 16 is 35° C., the required amount of the second heat transfer liquid 13 is supplied to the inlet end 12, the required amount being controlled so that the detected temperature of the first heat transfer liquid 11 at the outlet end 16 is maintained at the required set temperature.

[0043] Now, the required liquid temperature at the inlet end 12 required to maintain the required set temperature of 35°C at the outlet end 16 during normal operation of the air conditioner 32 is set to 30°C. To achieve this, the heat transfer liquid 2 in the heat exchange tank 33, which has been cooled by geothermal heat and has a temperature of 15°C, is supplied to the first heat transfer liquid 11 circulating through the heat transfer liquid circulation passage 7, thereby ensuring the required liquid temperature of 30°C at the outlet end 16. After that, when the load side 41 cools down to a certain extent, the amount of heat exchange in the first heat exchange section 6 can be reduced. In this case, if the detected temperature of the first heat transfer liquid 11 at the outlet end 16 indicates that the required liquid temperature at the inlet end 12 required to maintain the required set temperature of 35°C is 32°C, the required amount of the second heat transfer liquid 13 can be reduced compared to the initial amount. This required amount is automatically set by electrically controlling the three-way mixing valve 30 based on a temperature detection signal from a temperature detector 17 provided at the outlet end 16. Thereafter, as the load side 41 approaches the set temperature, the required amount further decreases, but this required amount is similarly set as required by the motorized control of the mixing three-way valve 30 .

[0044] Next, the second control will be described. There are two modes of the second control. The first mode of the second control is to control so that only the second heat transfer liquid 13 of the heat source 15 flows through the heat transfer liquid circulation flow path 7, regardless of the temperature of the first heat transfer liquid 11 detected by the temperature detector 17. The control is performed by driving the pump 23 with the first connection port 26 of the mixing three-way valve 30 fully closed and the third connection port 29 of the mixing three-way valve 30 fully opened by electrically controlling the valve body of the mixing three-way valve 30. In the case of the second control, the heating and cooling device 32 can be operated in heating or cooling mode by switching the flow paths by the first and second three-way switching valves 57 and 66, as in the case of the first control.

[0045] The second aspect of the second control is to add the required amount of the second heat transfer liquid 13 of the heat source 15 to the required amount. By adding in this way, heat increase control is performed to supply the second heat transfer liquid 13 in an amount larger than the required amount on the side where the inlet end 12 exists so that the first heat exchange section 6 can provide a heat amount greater than that required. The required amount of the second heat transfer liquid 13 to be added to the required amount is set according to the efficiency of the heat pump and the heat amount of the heat source 15. The amount of the second heat transfer liquid 13 to be added is set to an optimal amount so that the temperature detected by the temperature detector 17 becomes the set temperature, within a range in which the efficiency of the heat pump does not decrease.

[0046] The second control can be performed at any time while a set proportion of the heat amount, set within a range of 10 to 90%, of the initial heat amount of the heat source 15 remains in the heat source 15. Here, the initial heat amount refers to the maximum set heat amount of the heat source 15. This maximum set heat amount is set as required for each heat source. However, when the output of the heat pump drops to a set output that is 50% or less of its maximum output, the second control is changed to the first control.

[0047] Here, the "set proportion of heat quantity" remaining in the heat source 15 is set in the range of 10 to 90% of the initial heat quantity of the heat source 15, as described above. The "set proportion" is set in relation to the magnitude of the initial heat quantity, which is determined by the volume and number of the heat exchange reservoirs 33 buried underground, so as not to cause depletion of the heat source 15 at the end of operation of the water-cooled heat pump air conditioning device 32, which is operated by changing from the second control to the first control. The set proportion is set, for example, to 40 to 70% of the initial heat quantity.

[0048] Moreover, when the output of the heat pump 8 drops to a set output of 50% or less of its maximum output, the second control is changed to the first control. This set output is set in consideration of the type and specifications of the heat pump, and is set to, for example, 20% of the maximum output.

[0049] The output of the heat pump 8 during operation can be grasped from the output signal of the heat pump. Alternatively, the output can be estimated by calculation using, for example, the temperature difference between the liquid temperature at the inlet end 12 and the liquid temperature at the outlet end 16.

[0050] The operation modes of the water-cooled heat pump cooling and heating device 32 having such a configuration can be exemplified as the following modes (1), (2), and (3) on the premise that the first and second conditions are satisfied. When the air conditioner 32 is operated under the second control, the second control of the first aspect is continuously executed if there is a margin of heat in the relationship between the load on the load side and the heat amount of the heat source 15, but the control may be changed to the second aspect within a range in which the efficiency of the heat pump 8 does not decrease, and the control of the first aspect may be changed to the second control of the second aspect midway in the relationship with the margin of heat in the heat source 15. Alternatively, the second control of the second aspect may be executed from the beginning.

[0051] (1) Example 1: When the air conditioning device 32 performs heating operation in winter, the second control is performed in the morning when the outside temperature is low and the room temperature is low (at this time, the output of the heat pump 8 is in a high state), and then, during the warmer daytime hours, the control is changed to the first control (at this time, the output of the heat pump 8 has dropped to below the 20%), and then, in the evening, when the outside temperature drops and the room temperature drops, the control is changed to the second control (at this time, the output of the heat pump 8 has risen to 30% or more). (2) Example 2: An example in which only the second control (the second control according to the first example or the second control according to the second example) is executed until the end of operation. (3) Example 3: A mode in which the second control (the second control according to the first aspect or the second control according to the second aspect) is changed to the first control.

[0052] Next, we will explain the effect of reducing the power consumption of a water-cooled heat pump when the control method of the present invention is adopted instead of the conventional control method of Patent Document 1 (a control method in which the required amount of the second heat transfer liquid is supplied to the heat transfer liquid circulation path).

[0053] Now, when the water-cooled heat pump air conditioner 32 is used for heating, the heat pump is operated with the temperature of the second heat transfer liquid 13 supplied to the inlet end 12 at 7° C. while the temperature of the outlet end 16 is set to 2° C. by the conventional control method, but the temperature of the second heat transfer liquid 13 at the outlet end 16 is set to a temperature higher than 2° C., for example, 10° C., by the second control of the control method according to the present invention. By setting in this way, the compression work load of the compressor 43 of the heat pump can be reduced while the heat exchange amount in the first heat exchange section 6 remains the same, and the power consumption of the heat pump can be reduced accordingly, resulting in cheaper electricity charges.

[0054] Conversely, when the water-cooled heat pump air conditioner 32 is used for cooling, the heat pump is operated with the temperature of the second heat transfer liquid 13 at the outlet end 16 set to 30° C. with the temperature of the outlet end 16 set to 35° C. by the conventional control method, but the temperature of the second heat transfer liquid 13 at the outlet end is set to a temperature lower than 30° C., for example, 20° C., by the second control of the control method according to the present invention. By setting in this way, the compression work of the compressor 45 of the heat pump can be reduced while the heat exchange amount in the first heat exchange section 6 remains the same, and the power consumption of the water-cooled heat pump can be reduced accordingly, resulting in cheaper electricity charges. EXAMPLES

[0055] The present invention is by no means limited to the above-described embodiments, and various design modifications are possible within the scope of the claims.

[0056] (1) The heat exchange tank 33 constituting the heat exchange device 1 may be configured as a groundwater collection tank in which groundwater can constantly flow in and out. In this case, the groundwater collection tank itself in which groundwater is constantly stored constitutes the heat source 15, and the stored groundwater is the heat transfer liquid 2 that can become the second heat transfer liquid 13. In this case, the first heat transfer liquid 11 discharged on the side where the outlet end 16 of the first heat exchange section 6 exists can be returned to a reduction well, for example, or stored in a water tank and used as water for melting snow. When the heat exchange device 1 is configured using the groundwater collection tank, the amount of groundwater used can be reduced, making it less likely to cause environmental problems such as land subsidence due to a decrease in groundwater level.

[0057] (2) The heat source 15 constituting the heat exchange device 1 is a heat source with a limited amount of heat that is constantly replenished, but the speed of replenishment is slow. The heat source 15 can be constituted using the above-mentioned heat exchange reservoir 33, or can be constituted using a reservoir that stores hot spring wastewater, industrial wastewater, or sewage waste liquid as a heat supply source. In such a configuration, the heat quantity of hot spring wastewater, industrial wastewater, or sewage that has been wasted can be effectively utilized by collecting heat through a heat exchange reservoir as a serpentine pipe, for example. In this case, the heat transfer liquid in the heat exchange reservoir is the second heat transfer liquid 13 held by the heat source 15.

[0058] (3) The method for controlling the heat exchanger of a water-cooled heat pump according to the present invention can be applied to, in addition to the above-mentioned air conditioners, refrigerators, freezers, ice makers, hot water heaters, and snow melters. In these cases, the second control is performed in the initial stages of refrigeration, freezing, ice making, hot water supply, and snow melting, and when it is only necessary to maintain the state, such as maintaining the state cooled to the required temperature in refrigeration or maintaining the state of ice, the second control is changed to the first control under the above-mentioned first and second conditions.

[0059] (4) The flow rate required in the heat exchange section 6 can be adjusted by the flow rate adjustment function of the inverter of the pump 23 without using the flow rate adjustment valve 31 .

[0060] (5) In the embodiment shown in Fig. 3, the pump 23 is the same as in the embodiment 1, but the arrangement of the mixing three-way valve 30 is different from that in the embodiment 1. The mixing three-way valve 30 is arranged at a connection portion of the discharge pipe 22 to the heat transfer liquid circulation flow path 7, and the first, second and third connection ports 79, 80 and 81 of the mixing three-way valve 30 are connected to an upstream end 82 of the discharge pipe 22 and both side portions 83 and 85 of the heat transfer liquid circulation flow path 7, respectively. In Fig. 3(A), the flow rate adjustment is performed by inverter control of the pump 23, so the flow rate adjustment valve 31 in Figs. 1 and 2 is not used. When the heat exchanger 1 is configured in this manner, there are the following advantages. That is, as in the heat exchanger 1 according to the first embodiment, when the mixing three-way valve 30 is interposed at the connection portion 25 of the supply pipe 19 to the heat transfer liquid circulation passage 7 and the pump 23 is interposed between the mixing three-way valve 30 and the inlet end 12, the second heat transfer liquid 13 flowing into the mixing three-way valve 30 is throttled by the mixing three-way valve 30 and sucked by the pump 23, so that the air dissolved in the second heat transfer liquid 13 turns into bubbles. Therefore, the heat transfer liquid containing the bubbles flows into the inlet end 12 and is supplied to the first heat exchange section 6, so that there is a problem that the heat exchange efficiency in the first heat exchange section 6 is deteriorated due to the inclusion of the bubbles. In contrast, in the embodiment shown in FIG. 3, the heat transfer liquid pressurized by the pump 23 passes through the mixing three-way valve 30, so that the air dissolved in the heat transfer liquid is less likely to turn into bubbles, and the heat exchange efficiency is less likely to deteriorate.

[0061] (6) In the embodiment shown in FIG. 3, the pump 23 may be disposed between the outlet end 16 and the three-way mixing valve 30 disposed as described above, as shown by the dashed line in the figure.

[0062] (7) The mixing three-way valve 30 can be replaced with two flow rate regulating two-way valves 86, 87, for example, as shown in FIG.

[0063] (8) When the heat exchange tank 33 is not configured as a sealed water tank, the heat transfer liquid 2 in the heat exchange tank 33 can be supplied to the first pipe 55 via a submersible pump. [Explanation of symbols]

[0064] 1 Heat exchange device 2 Heat transfer liquid 3. Flow Path 5 Second heat exchange section 6 First heat exchange section 7 Heat transfer fluid circulation path 8. Water-cooled heat pump 11 First heat transfer fluid 12 Inlet end 13 Second heat transfer fluid 15 Heat source 16 Outlet end 17 Temperature detector 19 Supply pipe 22 Discharge pipe 23 Pump 25 Connection part 26 First connection port 27 Second connection port 29 Third Connection Port 30 Mixing three-way valve 31 Flow control valve 32 Water-cooled heat pump air conditioning system 33 Heat exchange reservoir 35 Wall 37 Closed Water Tank 47 Surrounding underground 79 First Connection Port 80 Second Connection Port 81 Third Connection Port

Claims

[Claim 1] A control method for a heat exchanger of a water-cooled heat pump, characterized by satisfying the following requirements. (1) A control method for a heat exchanger of a water-cooled heat pump for controlling the temperature of the load side (41) to a set temperature, the control method including a first control and a second control. (2) The heat exchange device is provided with a flow path (3) through which a heat transfer liquid (2) flows, the flow path (3) is provided with a heat transfer liquid circulation flow path (7) having a first heat exchange section (6) which performs heat exchange with a second heat exchange section (5), the heat pump heat medium of the water-cooled heat pump (8) flows in the second heat exchange section (5), a certain amount of a first heat transfer liquid (11) is circulated in the heat transfer liquid circulation flow path (7), and a second heat transfer liquid (13) having a temperature difference from that of the first heat transfer liquid (11) is supplied from a heat source (15) which holds a second heat transfer liquid (13) on the side where the inlet end (12) of the first heat exchange section (6) exists, and the first heat exchange section (6) A temperature detector (17) is provided for detecting the temperature of the first heat transfer liquid (11) at the outlet end (16) of the refrigerant passage, and the refrigerant passage is configured to discharge the first heat transfer liquid (11) in an amount equal to the amount of the second heat transfer liquid (13) supplied from the side where the outlet end (16) is present. (3) The first control is to control the supply of the second heat transfer liquid (13) from the heat source (15) in an amount sufficient to provide the amount of heat required by the first heat exchange section (6) on the side where the inlet end (12) of the first heat exchange section (6) is present, so that the detected temperature of the first heat transfer liquid (11) by the temperature detector (17) at the outlet end (16) of the first heat exchange section is maintained at a required set temperature. (4) The second control is a control is performed so that only the second heat transfer liquid (13) of the heat source (15) flows through the heat transfer liquid circulation path (7) regardless of the temperature of the first heat transfer liquid (11) detected by the temperature detector (17); Alternatively, the heat increase control is performed by adding a required amount of the second heat transfer liquid (13) of the heat source (15) to the required amount. The required amount is set so that the temperature detected by the temperature detector (17) becomes a set temperature within a range in which the efficiency of the water-cooled heat pump is not reduced. (5) The second control is executed when both the first and second conditions below are satisfied, and when either of the conditions is no longer satisfied, the second control is changed to the first control. First condition: A required set ratio of heat quantity set within a range of 10 to 90% of the initial heat quantity of the heat source remains in the heat source. Here, the initial heat quantity refers to the maximum set heat quantity of the heat source. This maximum set heat quantity is set as required for each heat source. Second condition: The output of the water-cooled heat pump must not fall below the required set output, which is set at 50% or less of its maximum output. (6) When a state in which both the first condition and the second condition are satisfied occurs while the first control is being executed, the first control is changed to the second control.

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