JP7359413B2 - Backwash system, backwash method, and backwash program - Google Patents

Description

The present invention relates to a backwash system, a backwash method, and a backwash program for backwashing a well.

Conventionally, systems in which groundwater flows through channels are known. For example, the groundwater heat exchange device described in Patent Document 1 has a flow path through which groundwater flows, pumps groundwater from a pumping well, performs heat exchange in a heat pump, and returns the groundwater after being used for heat exchange to a well. reduce to

Japanese Patent Application Publication No. 2011-21804

In the conventional device, if groundwater continues to flow in one direction, foreign matter may accumulate in a well or the like where groundwater is returned, making it difficult for groundwater to flow. For this reason, it is conceivable to perform backwashing, in which groundwater flows in the opposite direction, to clean the well. However, when backwashing was performed at a constant flow rate, there was a possibility that the cleaning effect would be reduced.

An object of the present invention is to provide a backwash system, a backwash method, and a backwash program that improve the effectiveness of backwash cleaning.

The backwash system according to the first aspect of the present invention pumps groundwater from one of a first well and a second well, and discharges the groundwater to the other well through a flow path. a groundwater control means; an intermittent backwashing means for performing intermittent backwashing of washing the first well or the second well by intermittently flowing the groundwater in a reverse direction ; and a period of time during which the groundwater control means flows the groundwater; a driving time measuring means for measuring the driving time; a first driving time determining means for determining whether the driving time measured by the driving time measuring means is equal to or longer than a first predetermined time; a second operation time determination means for determining whether or not the operation time measured by the time measurement means is longer than a second predetermined time that is longer than the first predetermined time; and the second operation time determination means forced backwashing means that stops pumping and drainage of the groundwater by the groundwater control means and performs the intermittent backwashing when it is determined that the operating time is equal to or longer than the second predetermined time, The intermittent backwash means is configured to stop pumping and draining of the groundwater by the groundwater control means when the first operation time determination means determines that the operation time is equal to or longer than the first predetermined time. If so, perform the intermittent backwashing described above . In this case, when performing backwashing, the intermittent backwashing means causes groundwater to flow intermittently. Therefore, compared to the case where backwashing is performed at a constant flow rate, the water flow changes and the cleaning effect is improved. Moreover, when the first predetermined time period has elapsed and the pumping and drainage of groundwater is stopped, intermittent backwashing is performed by the intermittent backwashing means. Since intermittent backwashing is performed when groundwater is not being pumped up or drained, the operations of groundwater pumping and drainage are prevented from being disturbed. On the other hand, if the pumping and draining of groundwater is not stopped even after the first predetermined time has elapsed, and the second predetermined time has elapsed, the forced backwashing means stops pumping and draining the groundwater and Perform backwashing. Therefore, even after the second predetermined period of time has elapsed, the amount of foreign matter and the like that accumulates in the well can be reduced compared to the case where intermittent backwashing is not performed.

The backwashing system includes a backwashing system that determines whether an increase in the water level of the groundwater in the well from which the groundwater is discharged, out of the first well and the second well, is equal to or greater than a predetermined increase. The intermittent backwashing may include an amount determining means, and the intermittent backwashing may perform the intermittent backwashing when the increase amount determining means determines that the amount of increase in the water level is equal to or greater than a predetermined amount of increase. If the amount of rise in groundwater level exceeds the specified amount of rise, drainage has been carried out in the same well for a long time, and foreign matter has accumulated in the groundwater flow path and the well from which groundwater is discharged. More likely. In this case, intermittent backwashing is automatically performed, so there is no need for the user to manually perform intermittent backwashing. Therefore, user convenience is improved.

The backwashing system includes a time determination unit that determines whether a predetermined time has arrived while the groundwater control unit stops pumping and draining the groundwater, and the intermittent backwashing unit determines whether or not a predetermined time has arrived. The intermittent backwashing may be performed when the determining means determines that a predetermined time has arrived. In this case, backwashing is performed during the time when underground water pumping and drainage is stopped. Therefore, it is possible to prevent backwashing from being performed during the time when underground water is being pumped and drained.

In the backwash system, the groundwater control means controls the first well and the second well when pumping and draining the groundwater again after the intermittent backwashing is performed by the intermittent backwashing means. Of these, the groundwater may be pumped from the well where the intermittent backwashing has been performed. In this case, the well from which groundwater was pumped before intermittent backwashing becomes the well from which drainage is performed after intermittent backwashing. In addition, the well from which groundwater was drained before intermittent backwashing becomes the well from which groundwater is pumped after intermittent backwashing. Therefore, compared to the case where water is always pumped from one of the first and second wells and drained to the other well, the balance of pumping and drainage loads between the first and second wells is lower. gets better. Therefore, it is possible to reduce the possibility that foreign matter and the like will continue to accumulate in a well that is constantly drained.

The backwash system is configured such that when the rise amount determining means determines that the rise amount of the water level of the groundwater in the well from which the groundwater is discharged is equal to or greater than a predetermined rise amount, Discharge control means for discharging the groundwater may be provided outside the second well. In this case, it is possible to prevent the rise in the water level of the groundwater in the well from which groundwater is discharged from continuing to increase beyond a predetermined rise. Further, it is possible to suppress an increase in the amount of foreign matter, etc. that accumulates in the first well or the second well from which groundwater is discharged. Moreover, it becomes possible to operate without stopping water pumping from the first well or the second well.

A backwashing method according to a second aspect of the present invention includes pumping groundwater from one of a first well and a second well, and discharging the groundwater to the other well through a flow path. a groundwater control step, an intermittent backwashing step of performing intermittent backwashing in which the groundwater is intermittently flowed in a reverse direction to wash the first well or the second well , and a time period for flowing the groundwater in the groundwater control step. a driving time measuring step for measuring a certain driving time; a first driving time determining step for determining whether the driving time measured in the driving time measuring step is a first predetermined time or more; and the driving time. a second operating time determining step of determining whether the operating time measured in the measuring step is longer than a second predetermined time that is longer than the first predetermined time; and a second operating time determining step. a forced backwashing step of stopping pumping and drainage of the groundwater by the groundwater control step and performing the intermittent backwashing when the operating time is determined to be equal to or longer than the second predetermined time; The intermittent backwashing step is performed when, in the first operation time determination step, it is determined that the operation time is equal to or longer than the first predetermined time, and when the pumping and drainage of the groundwater by the groundwater control step is stopped. If so, perform the intermittent backwashing described above . In this case, compared to backwashing at a constant flow rate, the water flow changes and the cleaning effect improves. Moreover, when the first predetermined time period has elapsed and the pumping and drainage of groundwater is stopped, intermittent backwashing is performed in the intermittent backwashing step. Since intermittent backwashing is performed when groundwater is not being pumped up or drained, the operations of groundwater pumping and drainage are prevented from being disturbed. On the other hand, if the pumping and draining of groundwater is not stopped even after the first predetermined time period has elapsed, and the second predetermined time period has elapsed, the pumping and draining of groundwater is stopped in the forced backwashing step and Perform backwashing. Therefore, even after the second predetermined period of time has elapsed, the amount of foreign matter and the like that accumulates in the well can be reduced compared to the case where intermittent backwashing is not performed.

A backwash program according to a third aspect of the present invention is configured to pump groundwater from one of a first well and a second well to a computer of a backwash system, and pump groundwater from the other well through a flow path. a groundwater control step of discharging the groundwater into a well; an intermittent backwashing step of performing intermittent backwashing of washing the first well or the second well by intermittently flowing the groundwater in the opposite direction; an operation time measurement step of measuring the operation time, which is the time for flowing the ground water; and a first operation time determination step of determining whether the operation time measured in the operation time measurement step is equal to or longer than a first predetermined time. a second operating time determining step of determining whether the operating time measured in the operating time measuring step is equal to or longer than a second predetermined time that is longer than the first predetermined time; Forced backwashing to perform the intermittent backwashing by stopping pumping and drainage of the groundwater in the groundwater control step when the operating time is determined to be equal to or longer than the second predetermined time in the second operation time determination step. and the intermittent backwashing step is performed when the operating time is determined to be equal to or longer than the first predetermined time in the first operating time determining step, and The above-mentioned intermittent backwashing is performed when pumping and drainage are stopped . In this case, compared to backwashing at a constant flow rate, the water flow changes and the cleaning effect improves. Moreover, when the first predetermined time period has elapsed and the pumping and drainage of groundwater is stopped, intermittent backwashing is performed in the intermittent backwashing step. Since intermittent backwashing is performed when groundwater is not being pumped up or drained, the operations of groundwater pumping and drainage are prevented from being disturbed. On the other hand, if the pumping and draining of groundwater is not stopped even after the first predetermined time period has elapsed, and the second predetermined time period has elapsed, the pumping and draining of groundwater is stopped in the forced backwashing step and Perform backwashing. Therefore, even after the second predetermined period of time has elapsed, the amount of foreign matter and the like that accumulates in the well can be reduced compared to the case where intermittent backwashing is not performed.

1 is a diagram showing the configuration of a groundwater utilization system 1. FIG. 1 is a diagram showing an electrical configuration of a groundwater utilization system 1. FIG. 3 is a data configuration diagram of a data table 95. FIG. FIG. 3 is a diagram showing the direction of backwashing in the groundwater utilization system 1. FIG. It is a flowchart of outdoor unit processing. It is a flowchart of main processing. 7 is a flowchart continuing from FIG. 6. It is a figure which shows the modification of backwashing in the groundwater utilization system 1. 8 is a flowchart of a first modification example of FIG. 7. FIG. 8 is a flowchart of a second modification example of FIG. 7. 8 is a flowchart of a third modification example of FIG. 7.

Below, a groundwater utilization system 1 embodying the present invention will be described. First, an overview of the groundwater utilization system 1 will be explained with reference to FIG. The groundwater utilization system 1 shown in FIG. 1 is a system that air-conditions the interior of a room 781 of a building 78 by using the heat of the groundwater 17. In the following description, the upper and lower sides of the paper surface of FIG. 1 will be referred to as the upper and lower sides of the groundwater utilization system 1. Further, the lower side of the groundwater utilization system 1 is in the gravity direction, and the upper side is in the anti-gravity direction.

The environment of the site where the groundwater utilization system 1 is installed will be explained. A first well 81, a second well 82, and a building 78 are present at the site where the groundwater utilization system 1 is installed. The building 78 is built above the ground surface 105. The first well 81 and the second well 82 are each provided downward from the ground surface 105. Groundwater 17 is stored in the first well 81 and the second well 82 . The groundwater 17 in the first well 81 and the second well 82 is supplied from a permeable stratum (not shown).

The configuration of the groundwater utilization system 1 will be explained. The groundwater utilization system 1 includes an indoor unit 10, an outdoor unit 20, a heat exchange unit 5, flow paths 11, 12, 13, 14, 901, 902, 903, 904, and the like.

In the groundwater 17 of the first well 81, one end of a flow path 901 and a flow path 902 are arranged. A pump 151 is connected to the end of the flow path 901 inside the first well 81 . The end of the flow path 902 in the first well 81 is an outlet 141 that is an opening. The outflow port 141 and the pump 151 are arranged below the water surface 811 of the groundwater 17 of the first well 81. In the groundwater 17 of the second well 82, one end of a channel 903 and a channel 904 are provided. A pump 152 is connected to an end of the flow path 903 inside the second well 82 . The end of the flow path 904 inside the second well 82 is an outlet 142 that is an opening. The outflow port 142 and the pump 152 are arranged below the water surface 821 of the groundwater 17 in the second well 82 .

In the first well 81, a water level sensor 971 is arranged above the water surface 811 of the groundwater 17. In the second well 82, a water level sensor 972 is arranged above the water surface 821 of the groundwater 17. The water level sensors 971, 972 are switch types that are turned on when the water surface 811, 821 rises to the position of the water level sensors 971, 972. The pumps 151, 152 and the water level sensors 971, 972 are electrically connected to the control panel 580 of the heat exchange unit 5 by electrical wiring (not shown).

The heat exchange unit 5 is one device covered by a case portion 590 that is an exterior. The case portion 590 is provided with connection ports 591, 592, 593, 594, 595, and 596 that can be connected to channels provided outside the heat exchange unit 5. A heat insulating material 598 is provided inside the case portion 590.

The heat exchange unit 5 includes flow paths 501 to 514, a discharge flow path 515, air bleed valves 941 and 942, a drainage drain pan 599, temperature sensors 571 to 574, pressure sensors 576 and 577, inside a rectangular parallelepiped case portion 590. Equipped with a safety valve 943, electric valves 561 to 568, on-off valves 569, 570, waste liquid valve 944, flow meter 575, pump 579, expansion tank 578, control panel 580, connection ports 591 to 596, operation part 588, and alarm 589. ing. Channels 501 to 509 are channels through which groundwater 17 flows. The channels 510 to 514 are channels through which the liquid 18, which is antifreeze, flows. Various electronic components are mounted on the control panel 580 to control the heat exchange unit 5.

The heat exchanger 50 is a device that exchanges heat between the groundwater 17 and the liquid 18. The heat exchanger 50 is fixed inside the heat exchange unit 5 by flanges 541, 542, 543, and 544 that are connection members. The heat exchanger 50 can be removed from the heat exchange unit 5 by opening the flanges 541 to 544. Therefore, the heat exchanger 50 can be removed from the heat exchange unit 5 and a new heat exchanger 50 can be installed in the heat exchange unit 5. That is, the heat exchanger 50 can be replaced by flange connection. When replacing the heat exchanger 50, the user, for example, removes a portion of the case portion 590 and replaces the heat exchanger 50.

Connection ports 591 to 596 are fixed to case portion 590. The flow path 901 is connected to the connection port 591. Flow path 902 is connected to connection port 592. Flow path 903 is connected to connection port 593. Flow path 904 is connected to connection port 594.

Flow path 501 is connected to heat exchanger 50 via flange 541. Flow path 501 extends from heat exchanger 50 and branches into flow paths 502 and 503 at connection portion 521 . The flow path 502 is connected to a connection port 591. The flow path 503 is connected to a connection port 592. The flow path 502 and the flow path 901 are connected to each other via a connection port 591. The flow path 503 and the flow path 902 are connected to each other via a connection port 592.

Flow path 504 is connected to heat exchanger 50 via flange 542. Flow path 504 extends from heat exchanger 50 and branches into flow paths 505 and 506 at connection portion 522 . Flow path 505 is connected to connection port 593. Flow path 506 is connected to connection port 594 . The flow path 505 and the flow path 903 are connected to each other via a connection port 593. The flow path 506 and the flow path 904 are connected to each other via a connection port 594.

Air bleed valve 941 is connected to one end of flow path 507. In this embodiment, the air bleed valve 941 is, for example, an air bleed valve with a check valve. The air bleed valve 941 is mechanical and operates automatically. The other end of the flow path 507 is connected to the flow path 501 at a connecting portion 523 .

The flow path 508 is connected to the flow path 501 at a connecting portion 524 . Flow path 508 extends toward a wastewater drain pan 599. One end of the flow path 501 is an outlet 551 that is an opening disposed above the drainage drain pan 599.

The flow path 509 is connected to the flow path 504 at a connecting portion 525. Flow path 509 extends toward wastewater drain pan 599. One end of the flow path 504 is an outlet 552 which is an opening located above the drainage drain pan 599.

A drain passage 515 is connected to the drain pan 599 . The discharge channel 515 extends to the outside of the case portion 590. Drain pan 599 receives groundwater 17 discharged from outlets 551 and 552 of channels 508 and 509. The groundwater 17 discharged into the drainage drain pan 599 is discharged to the outside of the heat exchange unit 5 via the discharge channel 515.

The electric valve 561 is provided between the connection portion 523 of the flow path 501 and the heat exchanger 50. The electric valve 562 is provided between the connection portion 525 of the flow path 504 and the heat exchanger 50. The electric valve 563 is provided in the flow path 502. The electric valve 564 is provided in the flow path 503. The electric valve 565 is provided in the flow path 505. Electrically operated valve 566 is provided in flow path 506 . The electric valve 567 is provided in the flow path 508. The electric valve 568 is provided in the flow path 509.

The temperature sensor 571 and the pressure sensor 576 are provided in the flow path 501 between the electric valve 561 and the heat exchanger 50. The temperature sensor 572 and the pressure sensor 577 are provided in the flow path 504 between the electric valve 562 and the heat exchanger 50.

Flow path 510 is connected to heat exchanger 50 via flange 543. Flow path 510 is connected to connection port 595. The flow path 511 is connected to the flow path 510 at a connecting portion 526. The flow path 512 is connected to the flow path 511 at a connecting portion 527. An air bleed valve 942 is provided at one end of the flow path 511. A safety valve 943 is provided at one end of the flow path 512. The air bleed valve 942 and the safety valve 943 are mechanical and operate automatically.

The on-off valve 569 is provided in the flow path 510 between the connection portion 526 and the heat exchanger 50. The on-off valve 569 is opened and closed manually. The temperature sensor 573 is provided in the flow path 510 between the on-off valve 569 and the connection portion 526.

Flow path 513 is connected to heat exchanger 50 via flange 544. The flow path 513 is connected to a connection port 596. The flow path 514 is connected to the flow path 513 at a connecting portion 528. A waste liquid valve 944 for maintenance is provided at one end of the flow path 514. When maintenance of the heat exchange unit 5 is performed, the waste liquid valve 944 is manually opened and the liquid 18 is discharged. The discharged liquid 18 is received in a container (not shown). Note that when the liquid 18 is sealed in the flow path 510 and the flow path 513 side, the liquid 18 is injected into the flow path 510 and the flow path 513 side from the waste liquid valve 944.

The on-off valve 570, the temperature sensor 574, the flow meter 575, the pump 579, and the expansion tank 578 are provided in this order in the flow path 513 in the direction from the heat exchanger 50 toward the connection portion 528. The density of the liquid 18 changes depending on the temperature. The expansion tank 578 is a tank provided to absorb changes in the density of the liquid 18. The flow meter 575 measures the flow rate of the liquid 18 flowing through the channel 513. The on-off valve 570 is opened and closed manually.

Control panel 580 is provided inside case portion 590. The operating section 588 and the alarm 589 are provided on the outer surface of the case section 590.

The outdoor unit 20 is provided outdoors (outside the building 78). The outdoor unit 20 is, for example, a water-cooled building multi-outdoor unit that is compatible with geothermal heat. The outdoor unit 20 includes a heat pump 2 and a control panel 210. The flow path 11 and the flow path 12 are connected to the heat pump 2 and the indoor unit 10, respectively. The flow path 13 and the flow path 14 are connected to the heat pump 2. The flow path 11 and the flow path 12 are flow paths through which the fluid 16 flows. Fluid 16 is, for example, a refrigerant. The flow paths 11 and 12 are refrigerant pipes. Control panel 210 controls heat pump 2 . Further, the control panel 210 is connected to the control panel 580 of the heat exchange unit 5 through electrical wiring (not shown).

The flow path 13 extends from the heat pump 2 to the outside of the outdoor unit 20 and is connected to the connection port 595 of the heat exchange unit 5. The flow path 14 extends from the heat pump 2 to the outside of the outdoor unit 20 and is connected to the connection port 596 of the heat exchange unit 5. The flow path 510 and the flow path 13 are connected to each other via a connection port 595. The flow path 513 and the flow path 14 are connected to each other via a connection port 596.

The liquid 18 flows inside the channels 13, 14, 510, 513. The liquid 18 is caused to flow through the flow path 510, the flow path 13, the heat pump 2, the flow path 14, the flow path 513, and the heat exchanger 50 in this order by the pump 579, and circulates through the paths. More specifically, the liquid 18 flows into the heat exchanger 50 via the flow path 513, undergoes heat exchange with the groundwater 17, and flows out from the flow path 510. The liquid 18 flows into the heat pump 2 via the flow path 13 , undergoes heat exchange with the fluid 16 , and flows out from the flow path 14 .

The indoor unit 10 is placed indoors 781 of the building 78. The fluid 16 flows through the heat pump 2, the flow path 11, the indoor unit 10, the flow path 12, and the heat pump 2 in this order, and circulates through the path. The indoor unit 10 takes in air from the room 781, exchanges heat with the fluid 16, adjusts the temperature of the air, and blows the air into the room 781 with a blower. As a result, the room 781 is cooled or heated. Although only one indoor unit 10 is illustrated, a plurality of indoor units may exist in a plurality of rooms.

The electrical configuration of the groundwater utilization system 1 will be described with reference to FIG. 2. The control panel 580 of the heat exchange unit 5 includes a CPU 581, a ROM 582, a RAM 583, and the like. The control panel 210 of the outdoor unit 20 includes a CPU 211, a ROM 212, and a RAM 213. The CPU 581 and the CPU 211 are electrically connected to each other and control the groundwater utilization system 1 by working together. The CPU 581 controls the heat exchange unit 5 and the pumps 151 and 152.

The CPU 211 of the outdoor unit 20 is electrically connected to the heat pump 2 and the indoor unit 10. The CPU 211 controls the heat pump 2 and the indoor unit 10. The indoor unit 10 includes an operation section 101. The CPU 211 and the CPU 581 control cooling and heating by the indoor unit 10 based on instructions from the user input from the operation unit 101.

CPU 211 of outdoor unit 20 is electrically connected to ROM 212 and RAM 213. The ROM 212 stores various program data such as a program for outdoor unit processing (see FIG. 5), which will be described later, as well as various other data. The RAM 213 stores various temporary data.

CPU 581 of heat exchange unit 5 is electrically connected to ROM 582 and RAM 583. The ROM 582 stores various program data such as a program for main processing (see FIGS. 6 and 7), which will be described later. Various temporary data is stored in the RAM 583.

The CPU 581 includes the heat exchanger 50, pumps 151, 152, pump 579, water level sensors 971, 972, flow meter 575, temperature sensors 571 to 574, pressure sensors 576, 577, operation unit 588, alarm 589, and electric valve 561. ~568 are electrically connected. The CPU 581 controls the electric valves 561 to 568 to open and close the flow path.

CPU 581 detects the temperature of groundwater 17 flowing through channels 501 and 504 based on the outputs of temperature sensors 571 and 572. CPU 581 detects the temperature of liquid 18 flowing through channels 510 and 513 based on the outputs of temperature sensors 573 and 574.

CPU 581 detects the pressure of groundwater 17 flowing through channels 501 and 504 based on the outputs of pressure sensors 576 and 577. The CPU 581 detects the flow rate of the liquid 18 flowing through the flow path 513 based on the output of the flow meter 575.

The CPU 581 controls the pumps 151 and 152 to supply the groundwater 17 from the first well 81 and the second well 82 to the heat exchanger 50 . In this embodiment, as an example, it is assumed that the pumps 151 and 152 are pumps (for example, inverter pumps) that can adjust the flow rate of the groundwater 17. The CPU 581 controls the flow rate of the groundwater 17 of the pumps 151 and 152 to adjust the flow rate of the groundwater 17 supplied from the first well 81 to the heat exchanger 50 . The CPU 581 adjusts the flow rate of the groundwater 17 by the pumps 151 and 152 while referring to the outputs of the temperature sensors 571 and 572.

The CPU 581 controls the pump 579 to cause the liquid 18 to flow. The liquid 18 flows through the flow path 510, the flow path 13, the heat pump 2, the flow path 14, the flow path 513, and the heat exchanger 50 in this order. In this embodiment, as an example, it is assumed that the pump 579 is a pump (for example, an inverter pump) that can adjust the flow rate of the groundwater 17. The CPU 581 adjusts the flow rate of the liquid 18 by the pump 579 while referring to the outputs of the temperature sensors 573 and 574. Further, the CPU 581 adjusts the flow rate of the liquid 18 while referring to the output of the flow meter 575.

The CPU 581 obtains user instructions input via the operation unit 588. The alarm 589 can turn on a light. The CPU 581 controls the lighting of the alarm 589 to notify the user.

The data table 95 will be explained with reference to FIG. The data table 95 is stored in various storage media such as ROM 582 or RAM 583, for example. The data table 95 includes a reference water level of the first well 81, a reference water level of the second well 82, a predetermined rise amount of the first well 81, a predetermined rise amount of the second well 82, a first predetermined time, a second predetermined time, and a predetermined time are stored. The reference water level of the first well 81 is, for example, the average value of the water level of the first well 81 in a state where the groundwater 17 is not pumped or returned. The reference water level of the second well 82 is, for example, the average value of the water level of the second well 82 in a state where the groundwater 17 is not pumped or returned.

The predetermined amount of rise of the first well 81 is a predetermined value of the amount of rise of the groundwater 17 from the reference water level of the first well 81. In this embodiment, as an example, it is set to a value lower than the maximum rise of groundwater 17 allowed in the first well 81 (for example, 70% of the maximum rise).

The predetermined amount of rise of the second well 82 is a predetermined value of the amount of rise of the groundwater 17 from the reference water level of the second well 82 . In this embodiment, as an example, it is set to a value lower than the maximum rise of groundwater 17 allowed in the second well 82 (for example, 70% of the maximum rise).

The first predetermined time is a reference time for performing intermittent backwashing, which will be described later, when the operating time is longer than the first predetermined time. The second predetermined time is a reference time for performing intermittent backwashing when the operating time is longer than the second predetermined time. The second predetermined time is longer than the first predetermined time. For example, the first predetermined time is 48 hours, and the second predetermined time is 72 hours. The predetermined time is the time at which intermittent backwashing is performed.

In this embodiment, the reference water level of the first well 81 is "K1", the reference water level of the second well 82 is "K2", the predetermined rise amount of the first well 81 is "K11", and the predetermined rise of the second well 82. It is assumed that the amount is "K21", the first predetermined time is "T1", the second predetermined time is "T2", and the predetermined time is "T3". Further, the water level sensor 971 is arranged at a position where it is turned on when the groundwater 17 in the first well 81 reaches a predetermined rise amount "K11". The water level sensor 972 is arranged at a position that turns on when the groundwater 17 in the second well 82 reaches a predetermined rise amount "K21".

With reference to FIG. 1, the flow of the groundwater 17, the liquid 18, and the fluid 16 when the room 781 is cooled or heated will be described. The heat exchanger 50 is configured to cool or heat the liquid 18 flowing in from the flow path 513 by using the temperature of the ground water 17 flowing in from the flow path 501 or 504 . The heat pump 2 is configured to use the temperature of the liquid 18 flowing in from the flow path 13 to cool or heat the fluid 16 flowing in from the flow path 14 using a heat pump method.

The CPU 581 opens the electric valves 561, 562, 563, and 566, closes the electric valves 564, 565, 567, and 568, and drives the pump 151. In this case, the groundwater 17 is pumped from the first well 81 and flows into the heat exchanger 50 via the flow path 901, the flow path 502, and the flow path 501. The heat exchanger 50 cools or heats the liquid 18 using the heat of the groundwater 17 that has flowed in. The groundwater 17 used for heat exchange flows out into the second well 82 via the flow path 504 , flow path 506 , flow path 903 , and outlet 142 . In the following description, the direction in which groundwater 17 flows, which is pumped from the first well 81 and flows out into the second well 82 via the heat exchanger 50, is referred to as a first direction H1.

The CPU 581 opens the electric valves 561, 562, 564, and 565, closes the electric valves 563, 566, 567, and 568, and drives the pump 152. In this case, the groundwater 17 is pumped from the second well 82 and flows into the heat exchanger 50 via the flow path 903, the flow path 505, and the flow path 504. The heat exchanger 50 cools or heats the liquid 18 using the heat of the groundwater 17 that has flowed in. The groundwater 17 used for heat exchange flows out into the first well 81 through the flow path 501, flow path 503, flow path 902, and outlet 141. In the following description, the flow direction of the groundwater 17 pumped from the second well 82 and flowing out into the first well 81 via the heat exchanger 50 will be referred to as a second direction H2.

CPU 581 drives pump 579. In this case, the liquid 18 flows in the order of the heat exchanger 50, the flow path 510, the flow path 13, the heat pump 2, the flow path 14, the flow path 513, and the heat exchanger 50, and circulates through the path. More specifically, liquid 18 enters heat exchanger 50 via channel 513 and exits from channel 510. The liquid 18 flows into the heat pump 2 through the flow path 13 and flows out through the flow path 14 . The direction in which the liquid 18 flows is defined as direction H3. The heat exchanger 50 uses the heat of the groundwater 17 to cool or heat the liquid 18 flowing therein. The heat pump 2 uses the heat of the liquid 18 that has flowed in to cool or heat the fluid 16.

The fluid 16 flows through the heat pump 2, the flow path 11, the indoor unit 10, the flow path 12, and the heat pump 2 in this order, and circulates through the path. The direction in which the fluid 16 flows is defined as direction H4. The indoor unit 10 cools or heats air through heat exchange with the cooled or heated fluid 16 to cool or heat the room 781 .

In this way, the room 781 is cooled or heated. The temperature of the groundwater 17 in the first well 81 and the second well 82 is stable compared to the outside air temperature. Therefore, the efficiency of the heat pump is improved compared to the case where the room 781 is cooled or heated by heat exchange with outside air.

Backwashing will be explained with reference to FIG. 1. When the groundwater 17 flows in the first direction H1 during cooling or heating of the room 781, the groundwater 17 flows out from the outlet 142 to the second well 82. If the flow of the groundwater 17 in the first direction H1 continues, foreign matter and the like may accumulate in the second well 82 and the like, making it difficult for the groundwater 17 to flow. For this reason, backwashing is performed by pumping up the groundwater 17 from the second well 82 and flowing the groundwater 17 in a direction opposite to the first direction H1, thereby reducing the possibility that the groundwater 17 becomes difficult to flow.

Further, it will be explained in detail. The wall portion forming the periphery of the second well 82 is formed, for example, in a mesh shape or in a round hole. The groundwater 17 flows in and out between the second well 82 and the strata around the second well 82 through the wall. If the groundwater 17 continues to flow in the first direction H1, there is a possibility that foreign matter will accumulate on the wall forming the periphery of the second well 82 and around the outflow port 142, making it difficult for the groundwater 17 to flow. be. Therefore, there is a possibility that the groundwater 17 will be pumped up from the second well 82 and backwashed by flowing the groundwater 17 in the opposite direction to the first direction H1 to remove foreign substances in the second well 82 and make it difficult for the groundwater 17 to flow. This reduces the

Note that if the groundwater 17 continues to flow in the first direction H1, foreign matter may also accumulate in the flow path from the first well 81 to the second well 82. When backwashing is performed, the groundwater 17 flows in the opposite direction also in a part of the flow path from the first well 81 to the second well 82, so the flow path is also washed. Therefore, the possibility that the groundwater 17 becomes difficult to flow in the channel can also be reduced.

When performing this backwashing, the CPU 581 opens the electric valves 561, 562, 565, and 567, closes the electric valves 563, 564, 566, and 568, and drives the pump 152. In this case, the groundwater 17 is pumped from the second well 82 and is passed through the drainage drain pan through the flow path 903, flow path 505, flow path 504, heat exchanger 50, flow path 501, flow path 508, and outlet 551. 599 is discharged. In this backwashing, the flow direction of the groundwater 17 pumped from the second well 82 and discharged from the outlet 551 is referred to as a backwash direction H5 (see FIG. 4). The groundwater 17 discharged into the drainage drain pan 599 is discharged to the outside of the heat exchange unit 5 via the discharge channel 515.

When the groundwater 17 flows in the second direction H2 during cooling or heating of the room 781, the groundwater 17 flows out from the outlet 141 into the first well 81. If the flow of the groundwater 17 in the second direction H2 continues, foreign matter and the like may accumulate in the first well 81 and the like, making it difficult for the groundwater 17 to flow. For this reason, backwashing is performed by pumping up the groundwater 17 from the first well 81 and flowing the groundwater 17 in a direction opposite to the second direction H2, thereby reducing the possibility that the groundwater 17 becomes difficult to flow. Note that, as in the case of the second well 82 described above, the wall portion forming the periphery of the first well 81 is formed in, for example, a mesh shape or a round hole. However, backwashing removes foreign matter that collects on the wall forming the periphery of the first well 81 and around the outflow port 141, reducing the possibility that the groundwater 17 will become difficult to flow. . Also, by backwashing, a part of the flow path from the second well 82 to the first well 81 is also cleaned.

When performing this backwashing, the CPU 581 opens the electric valves 561, 562, 563, and 568, closes the electric valves 564, 565, 566, and 567, and drives the pump 151. In this case, the groundwater 17 is pumped from the first well 81 and passed through the drainage drain pan through the flow path 901, the flow path 502, the flow path 501, the heat exchanger 50, the flow path 504, the flow path 509, and the outlet 552. 599 is discharged. In this backwashing, the flow direction of the groundwater 17 pumped from the first well 81 and discharged from the outlet 552 is referred to as a backwash direction H6 (see FIG. 4). The groundwater 17 discharged into the drainage drain pan 599 is discharged to the outside of the heat exchange unit 5 via the discharge channel 515.

In this embodiment, intermittent backwashing is performed in which the first well 81 or the second well 82 is washed by intermittently flowing the groundwater 17 in the opposite direction. Intermittent backwashing is backwashing in which, for example, backwashing is performed for 10 minutes, backwashing is stopped for 10 minutes, backwashing is performed again for 10 minutes, and backwashing is stopped for 10 minutes.

The processing executed by the CPU 581 and the CPU 211 will be explained. First, with reference to FIG. 5, outdoor unit processing executed by the CPU 211 of the outdoor unit 20 will be described. When the outdoor unit 20 is powered on, the CPU 211 reads the outdoor unit processing program from the ROM 212 and expands it to the RAM 213. The CPU 211 performs outdoor unit processing according to the outdoor unit processing program.

In the outdoor unit process, first, it is determined whether to start cooling or heating (S11). If cooling or heating is not to be started (S11: NO), standby. For example, when the user operates the operation unit 101 of the indoor unit 10 and inputs an instruction to start cooling or heating, the CPU 211 determines to start cooling or heating (S11: YES). Further, for example, when the difference between the temperature of the room 781 and the set temperature becomes equal to or higher than a predetermined temperature and the CPU 211 determines to start cooling or heating, it is determined to start cooling or heating (S11: YES ).

When it is determined to start cooling or heating (S11: YES), a start instruction signal, which is a signal indicating an instruction to start cooling or heating, is transmitted to the CPU 581 of the heat exchange unit 5 (S12). The transmitted start instruction signal is received in the process of S21 of the CPU 581 (see FIG. 6).

Next, cooling or heating is started (S13). More specifically, the heat pump 2 and the indoor unit 10 are driven. In the heat pump 2, heat exchange between the liquid 18 and the fluid 16 is performed. The fluid 16 is sent to the indoor unit 10, and the indoor unit 10 cools or heats the room 781.

Next, it is determined whether to stop cooling or heating (S14). If the cooling or heating is not stopped (S14: NO), the process returns to S14. That is, cooling or heating continues. For example, when the user operates the operation unit 101 and inputs an instruction to stop cooling or heating, it is determined that the cooling or heating should be stopped (S14: YES). Further, for example, when the temperature in the room 781 reaches the set temperature and the CPU 211 determines to stop cooling or heating, it is determined to stop cooling or heating (S14: YES). Next, a stop instruction signal, which is a signal indicating an instruction to stop cooling or heating, is transmitted to the CPU 581 (S15). The transmitted stop instruction signal is received in the process of S42 by the CPU 581 (see FIG. 7).

Next, cooling or heating is stopped (S16). More specifically, the driving of the heat pump 2 and the indoor unit 10 is stopped. The process then returns to S11.

The main processing by the CPU 581 of the heat exchange unit 5 will be explained with reference to FIGS. 6 and 7. When the heat exchange unit 5 is powered on, the CPU 581 reads the main processing program from the ROM 582 and expands it to the RAM 583. The CPU 581 performs main processing according to a main processing program.

In the main process, first, it is determined whether to start cooling or heating (S21). If cooling or heating is not to be started (S21: NO), it is determined whether a predetermined time "T3" (see FIG. 3) for starting intermittent backwashing has arrived (S22). The predetermined time "T3" is set to a time when the groundwater utilization system 1 is stopped, such as at night, for example. Note that the predetermined time can be set by the user operating the operation unit 101. If the predetermined time "T3" to start intermittent backwashing has not arrived (S22: NO), the process returns to S21.

When the start instruction signal transmitted in the process of S12 (see FIG. 5) is received, it is determined that cooling or heating is to be started (S21: YES), and the supply direction of the groundwater 17 to the heat exchanger 50 is It is determined whether the direction is H1 or the second direction H2 (S23).

For example, when changing the supply direction every day, if the groundwater 17 was flowed in the second direction H2 on the previous day, it is determined to flow in the first direction H1. Moreover, when the groundwater 17 was flowed in the first direction H1 on the previous day, it is determined to be flowed in the second direction H2. Furthermore, if the supply direction is preset by the user, it is determined that the groundwater 17 is to flow in the set direction. In this embodiment, as an example, when the groundwater 17 is pumped and drained again in S24 after intermittent backwashing is performed in S45 or S49 (see FIG. 7), the first well 81 and the second well 82, the direction in which the groundwater 17 flows is determined so that the groundwater 17 is pumped from the same well as the well from which the groundwater 17 was pumped when intermittent backwashing was performed.

Next, the pump 151 or the pump 152 is controlled, and the groundwater 17 is supplied to the heat exchanger 50 (S24). If it is determined in S23 to supply the groundwater 17 in the first direction H1, the pump 151 is driven and the groundwater 17 is supplied from the first well 81 to the heat exchanger 50 (S24). Groundwater 17 discharged from heat exchanger 50 is discharged from outlet 142 to second well 82 . In S23, if it is determined to supply the groundwater 17 in the second direction H2, the pump 152 is driven, and the groundwater 17 is supplied from the second well 82 to the heat exchanger 50 (S24). Groundwater 17 discharged from heat exchanger 50 is discharged from outlet 141 to first well 81 . That is, in S24, a process is performed in which the groundwater 17 is pumped up from one of the first well 81 and the second well 82, and the groundwater 17 is discharged into the other well through the flow path. Note that when the groundwater 17 is caused to flow in the first direction H1 or the second direction H2, the electric valves 561 to 568 are opened and closed as described above.

Next, the pump 579 is controlled and the liquid 18 is fed (S25). As a result, the liquid 18 is supplied to the heat exchanger 50, and the liquid 18 after heat exchange is supplied to the heat pump 2.

Next, the heat exchanger 50 is controlled, and heat exchange between the groundwater 17 and the liquid 18 is started (S26). Thereby, heat exchange is performed in the heat exchanger 50 and the heat pump 2, and the room 781 is cooled or heated. Next, measurement of the operating time, which is the time during which the groundwater 17 is flowing, is started (S27). Note that the driving time is cumulatively measured until the driving time is set to "0" in the process of S47, which will be described later. That is, if S27 is executed again after the measurement of the driving time has been started in S27 and stopped in S43, which will be described later, the time will be calculated from the continuation of the driving time for which measurement was stopped in S43. are accumulated.

Next, as shown in FIG. 7, a first temperature, which is the temperature of the groundwater 17 flowing into the heat exchanger 50, is measured (S28). When the groundwater 17 is flowing in the first direction H1 (see FIG. 1), the first temperature is measured based on the output of the temperature sensor 571. When the groundwater 17 is flowing in the second direction H2 (see FIG. 2), the first temperature is measured based on the output of the temperature sensor 572.

A second temperature, which is the temperature of the groundwater 17 flowing out from the heat exchanger 50, is measured (S29). When the groundwater 17 is flowing in the first direction H1, the second temperature is measured based on the output of the temperature sensor 572. When the groundwater 17 is flowing in the second direction H2, the second temperature is measured based on the output of the temperature sensor 571.

Next, the flow rate of the groundwater 17 by the pumps 151 and 152 is adjusted based on the temperature difference between the first temperature acquired in S28 and the second temperature acquired in S29 (S30). Thereby, the groundwater 17 is supplied to the heat exchanger 50 at the adjusted flow rate. For example, the CPU 581 adjusts the flow rate of the groundwater 17 so that the temperature difference between the first temperature and the second temperature is constant (for example, 5 degrees).

Next, a third temperature, which is the temperature of the liquid 18 flowing into the heat exchanger 50, is measured (S31). In S31, a third temperature is measured based on the output of temperature sensor 574.

Next, a fourth temperature, which is the temperature of the liquid 18 flowing out from the heat exchanger 50, is measured (S32). In S32, a fourth temperature is measured based on the output of temperature sensor 573.

Next, the flow rate of the liquid 18 by the pump 579 is adjusted based on the temperature difference between the third temperature acquired in S31 and the fourth temperature acquired in S32 (S33). This supplies liquid 18 to heat exchanger 50 at a regulated flow rate. For example, the CPU 581 adjusts the flow rate of the liquid 18 so that the temperature difference between the third temperature and the fourth temperature is constant (for example, 5 degrees).

Next, the pressure of the groundwater 17 flowing into the heat exchanger 50 is measured (S34). When the groundwater 17 is flowing in the first direction H1, the pressure of the groundwater 17 flowing into the heat exchanger 50 is measured based on the output of the pressure sensor 576. When the groundwater 17 is flowing in the second direction, the pressure of the groundwater 17 flowing into the heat exchanger 50 is measured based on the output of the pressure sensor 577.

Next, it is determined whether the pressure of the groundwater 17 acquired in S34 is equal to or higher than a predetermined pressure (S35). The predetermined pressure is set to, for example, a pressure at which the heat exchanger 50 is clogged with foreign matter, making it difficult for the underground water 17 to flow, and the pressure increases and the heat exchanger 50 needs to be replaced. The predetermined pressure is stored in RAM 583. The predetermined pressure is, for example, 0.2 MPaG. If the pressure of the groundwater 17 acquired in S34 is not equal to or higher than the predetermined pressure (S35: NO), the process of S37, which will be described later, is executed.

When the pressure of the groundwater 17 acquired in S34 is equal to or higher than the predetermined pressure (S35: YES), notification is performed (S36). In this embodiment, the alarm 589 (see FIGS. 1 and 2) lights up. This allows the user to be informed that it is time to replace the heat exchanger 50. Note that the determination of clogging of the heat exchanger 50 in S35 may be based on the pressure difference (pressure loss) of the heat exchanger 50. For example, when the pressure difference between the pressure sensor 576 and the pressure sensor 577 exceeds a predetermined pressure difference (for example, 0.1 MPa) (S35: YES), the process of S36 described later may be executed.

Next, the water level of the groundwater 17 in the well from which the groundwater 17 is discharged is detected between the first well 81 and the second well 82 (S37). In S37, when the groundwater 17 is flowing in the first direction H1, the water level of the groundwater 17 in the second well 82 is detected based on the output of the water level sensor 972. When the groundwater 17 is flowing in the second direction H2, the water level of the groundwater 17 in the first well 81 is detected based on the output of the water level sensor 971. In this practical embodiment, the water level sensors 971, 972 are switch type, so whether or not the water surface 811, 821 of the groundwater 17 has reached the position of the water level sensors 971, 972 is detected.

Next, it is determined whether or not the amount of increase in the water level of the groundwater 17 in the well from which the groundwater 17 is discharged, out of the first well 81 and the second well 82, is equal to or greater than a predetermined amount of increase (S38). When the groundwater 17 is flowing in the first direction H1, it is determined whether the amount of increase in the water level in the second well 82 is equal to or greater than the predetermined amount of increase in the second well 82 "K21" (see FIG. 3). (S38). In S37, when it is detected that the water surface 821 of the groundwater 17 has reached the position of the water level sensor 972, the amount of rise in the water level of the groundwater 17 in the second well 82 from which the groundwater 17 is discharged is determined to be the predetermined rise amount "K21". It is determined that the above is the case (S38: YES). Further, when the groundwater 17 is flowing in the second direction H2, whether the amount of increase in the water level in the first well 81 is equal to or greater than the predetermined amount of increase in the first well 81 "K11" (see FIG. 3). is determined (S38). In S37, when it is detected that the water surface 811 of the groundwater 17 has reached the position of the water level sensor 971, the amount of rise in the water level of the groundwater 17 in the first well 81 from which the groundwater 17 is discharged is determined to be the predetermined rise amount "K11". It is determined that the above is the case (S38: YES).

If the amount of increase in the water level of the groundwater 17 in the well from which the groundwater 17 is discharged among the first well 81 and the second well 82 is not greater than the predetermined amount of increase (S38: NO), the operation in which the measurement was started in S27 It is determined whether the time is longer than the first predetermined time "T1" (see FIG. 3) (S39). The first predetermined time "T1" is, for example, 48 hours.

If the operating time for which the measurement was started in S27 is not longer than the first predetermined time "T1" (S39: NO), it is determined whether to stop cooling or heating (S42). In S42, if the stop instruction signal transmitted in S15 (see FIG. 5) is received, it is determined to stop cooling or heating. If the cooling or heating is not to be stopped (S42: NO), the process returns to S28.

If the amount of increase in the water level of the groundwater 17 in the well from which the groundwater 17 is discharged out of the first well 81 and the second well 82 is equal to or greater than the predetermined amount of increase (S38: YES), the process proceeds to S40. Further, if the driving time is longer than the first predetermined time "T1" (S39: YES), the process proceeds to S40. In S40, the backwash flag M is set to "1" and stored in the RAM 583. The backwash flag M is a variable for determining whether or not to perform backwashing. When the backwash flag M is "1", intermittent backwash is executed in the process of S45 (see FIG. 6), which will be described later.

Next, it is determined whether the operating time for which measurement was started in S27 is equal to or longer than a second predetermined time "T2" (see FIG. 3) (S41). The second predetermined time "T2" is, for example, 72 hours. If it is not longer than the second predetermined time "T2" (see FIG. 3) (S41: NO), the process proceeds to S42.

If cooling or heating is to be stopped (S42: YES), the cooling or heating operation is stopped (S43). In S43, pumps 151, 152 and pump 579 are stopped. As a result, the operation of pumping up the groundwater 17 from one of the first well 81 and the second well 82 and discharging the groundwater 17 to the other well through the flow path is stopped. Further, the feeding of the liquid 18 is stopped. Further, the operation of the heat exchanger 50 is also stopped. Furthermore, the measurement of the operating time that was started in S27 is stopped. Note that the operations of the heat pump 2 and the indoor unit 10 are also stopped under the control of the CPU 211 of the outdoor unit 20 (see S16 in FIG. 5). Then, the process returns to S21 (see FIG. 6).

As shown in FIG. 6, if it is determined in S22 that the predetermined time "T3" (see FIG. 3) has arrived (S22: YES), it is determined whether the backwash flag M is "1". Thus, it is determined whether or not to perform backwashing (S44). If the backwash flag M is "0", it is determined that backwashing is not to be performed (S44: NO), and the process returns to S21.

When the backwashing flag M is "1", it is determined that backwashing is to be performed (S44: YES), and intermittent backwashing is performed (S45). In this embodiment, as an example, it is assumed that an operation of performing backwashing for 10 minutes and stopping backwashing for 10 minutes is repeated five times. That is, backwashing for 10 minutes is performed five times.

When the intermittent backwashing is completed, the backwash flag M is set to "0" and stored in the RAM 583 (S46). Next, the operating time for which measurement was started in S27 is set to "0" (S47). The process then returns to S21. In this way, the operation of the groundwater utilization system 1 is stopped (that is, the operation of pumping groundwater 17 from one well and discharging the groundwater 17 to the other well through the flow path is stopped, and the operation of air conditioning or heating is stopped). intermittent backwashing is performed (S45) while the engine is stopped (for example, at night).

While the groundwater utilization system 1 is in operation, if the operating time exceeds the second predetermined time "T2" in S41 (S41: YES), the cooling or heating operation is stopped as in S43. (S48). As a result, the operation of pumping up groundwater 17 from one well and discharging groundwater 17 to the other well via the channel is stopped. Next, intermittent backwashing is performed similarly to S45 (S49). Next, similar to S46, the backwash flag M is set to "0" (S50). Next, similarly to S47, the operating time for which measurement was started in S27 is set to "0" (S51). The process then returns to S23.

In this way, if the instruction to stop the heating and cooling is not input in S42 and the operating time reaches the second predetermined time "T2" (S41: YES), the operation of the groundwater utilization system 1 is forcibly stopped ( S48), and intermittent backwashing is performed (S49). After the intermittent backwashing is completed, the operation (ie, cooling or heating) of the groundwater utilization system 1 is automatically started (S23 to S27).

In addition, when the groundwater 17 is pumped and drained again in S24 after intermittent backwashing is performed in S45 or S49, intermittent backwashing is performed in the first well 81 and the second well 82. The groundwater 17 is pumped from the same well as the well from which the groundwater 17 was pumped when the groundwater 17 was pumped. That is, when the groundwater 17 is pumped up from the second well 82 in S45 or S49 (backwash direction H5 in FIG. 4), the groundwater 17 is pumped up from the second well 82 in S24 ( second direction H2 in FIG. 1). In the intermittent backwashing of S45 or S49, if the groundwater 17 is pumped up from the first well 81 (backwash direction H6 in FIG. 4), the groundwater 17 is pumped up from the first well 81 in S24 (backwash direction H6 in FIG. 1). first direction H1).

As described above, the processing in this embodiment is executed. In this embodiment, the heat exchange unit 5 includes a case portion 590. The heat exchange unit 5 also includes a heat exchanger 50 that exchanges heat between the groundwater 17 and the liquid 18. The heat exchange unit 5 also includes a CPU 581 that controls the pump 151 or the pump 152 and supplies the groundwater 17 to the heat exchanger 50. The heat exchange unit 5 also includes a CPU 581 that controls the pump 579 and supplies the liquid 18 to the heat exchanger 50. The CPU 581 and the heat exchanger 50 are provided inside the case portion 590. That is, the CPU 581 that controls supply of the groundwater 17 and the liquid 18 to the heat exchanger 50, the heat exchanger 50, and the case portion 590 are provided in one heat exchange unit 5. Therefore, when performing installation work on site, by simply installing one heat exchange unit 5, the CPU 581, which is the first control means that controls the supply of groundwater 17 to the heat exchanger 50, and the supply of liquid 18, can be installed. A CPU 581, which is a second control means that controls supply to the heat exchanger 50, and the heat exchanger 50 can be installed. That is, the CPU 581 and the heat exchanger 50 can be installed by simply installing the heat exchange unit 5 that has been produced in advance at a manufacturing factory or the like. For this reason, the first control means for supplying the groundwater 17 to the heat exchanger 50, the second control means for supplying the liquid 18 to the heat exchanger 50, and the heat exchanger 50 are provided separately, and the case part The number of man-hours required for installation work is reduced compared to the case where 590 is not provided. Furthermore, the number of man-hours required to create design drawings for installation work is also reduced. Therefore, the cost of installation work can be reduced.

Further, the CPU 581 is one component arranged on one control panel 580. That is, the first control means that controls the supply of groundwater 17 to the heat exchanger 50 and the second control means that controls the supply of the liquid 18 to the heat exchanger 50 are controlled by the CPU 581, which is one component. and arranged on one control panel 580. Therefore, when the first control means for supplying the groundwater 17 to the heat exchanger 50 and the second control means for supplying the liquid 18 to the heat exchanger 50 are separate parts and are arranged in separate control panels. Compared to the above, the number of control panels is reduced, and the cost of the heat exchange unit 5 can be reduced.

Moreover, the pumps 151 and 152 are pumps that can adjust the flow rate of the groundwater 17. Then, the first temperature is measured (S28), and the second temperature is measured (S29). Based on the temperature difference between the first temperature and the second temperature, the pumps 151 and 152 are controlled, and the flow rate of the groundwater 17 is adjusted (S30). Therefore, when the flow rate of the groundwater 17 can be reduced, the power consumption of the pumps 151 and 152 can be reduced by reducing the flow rate. Therefore, power consumption is reduced compared to a case where the flow rate of the groundwater 17 is not adjusted and the groundwater 17 is always allowed to flow at a constant flow rate. Therefore, the operating costs of the heat exchange unit 5 and the groundwater utilization system 1 can be reduced.

Further, the pump 579 is a pump that can adjust the flow rate of the liquid 18. Then, a third temperature is measured (S31), and a fourth temperature is measured (S32). The flow rate of the liquid 18 is adjusted based on the temperature difference between the third temperature and the fourth temperature (S33). Therefore, if the flow rate of the liquid 18 can be reduced, the power consumption of the pump 579 can be reduced by reducing the flow rate. Therefore, power consumption is reduced compared to the case where the flow rate of the liquid 18 is not adjusted and the underground water 17 is always allowed to flow at a constant flow rate. Therefore, the operating costs of the heat exchange unit 5 and the groundwater utilization system 1 can be reduced.

Moreover, the heat exchanger 50 can be replaced by flange connection. Therefore, when the heat exchanger 50 becomes clogged with foreign matter and needs to be replaced, there is no need to cut and weld the piping inside the heat exchange unit 5. Further, there is no need for expensive cleaning of the heat exchanger, such as decomposition cleaning, chemical cleaning, and neutralization treatment. Therefore, the replacement cost when the heat exchanger 50 deteriorates is reduced. This reduces maintenance costs for the heat exchange unit 5 and the groundwater utilization system 1.

Furthermore, the pressure of the groundwater 17 flowing into the heat exchanger 50 is measured (S34). If the measured pressure is equal to or higher than the predetermined pressure (S35: YES), a notification is issued (S36). When the heat exchanger 50 is clogged with foreign matter, the pressure of the groundwater flowing into the heat exchanger increases to a predetermined pressure or higher. In this case, since the user is notified, the user can easily determine that it is time to replace the heat exchanger 50. Therefore, user convenience is improved. Note that the user may, for example, replace the heat exchanger 50, replace the entire heat exchange unit 5, or replace the filter inside the heat exchanger 50 to prevent foreign matter from clogging the heat exchanger 50. It can be set to no state.

Further, inside the case portion 590, channels 501 to 506 for the ground water 17, channels 510 and 513 for the liquid 18, and a heat exchanger 50 are provided. A heat insulating material 598 is provided in the case portion 590. Therefore, the flow paths 501 to 506 for the underground water 17, the flow path 510 for the liquid 18, and the heat exchanger 50 provided inside the case part 590 are protected from the temperature outside the heat exchange unit 5 by the heat insulating material 598. be done. Since the heat insulating material 598 is provided, there is no need to arrange a heat insulating material in each of the flow paths 501 to 506 of the underground water 17, the flow paths 510 and 513 of the liquid 18, and the heat exchanger 50. Therefore, costs can be reduced compared to the case where a heat insulating material is individually arranged in the flow paths 501 to 506 of the ground water 17, the flow paths 510 and 513 of the liquid 18, and the heat exchanger 50. Furthermore, when the heat exchange unit 5 is placed on site, there is no need to perform construction work on the insulation material on site. Therefore, the construction period can be shortened and the cost of installation work can be reduced.

An air bleed valve 941 with a check valve is provided in the flow path of the groundwater 17 . In this case, air contained in the flow path of the groundwater 17 in the heat exchange unit 5 can be removed. Furthermore, even when the pumps 151 and 152 are stopped, the possibility that the groundwater 17 in the flow path will flow out can be reduced. Therefore, the pump power at the time of starting the drive of the pumps 151, 152 can be reduced, and due to the siphon effect, the power of the pumps 151, 152 does not require pumping water, and is reduced to only the piping resistance of the flow path.

Moreover, the CPU 581 pumps up the groundwater 17 from one of the first well 81 and the second well 82, and discharges the groundwater 17 to the other well through the flow path (S24). Further, the CPU 581 executes intermittent backwashing in which the groundwater 17 is intermittently flowed in the reverse direction to clean the first well 81 or the second well 82 (S45). When backwashing is performed, the groundwater 17 is intermittently flushed, so compared to when backwashing is performed at a constant flow rate, the water flow changes, and the pumped water of either the first well 81 or the second well 82 is The effectiveness of well cleaning performed is improved.

Further, if the amount of increase in the water level of the groundwater 17 in the well from which the groundwater 17 is discharged among the first well 81 and the second well 82 is equal to or greater than a predetermined amount of increase (S38: YES), intermittent backwashing is performed. It is executed (S44). When the amount of rise in the water level of groundwater 17 exceeds a predetermined amount of rise, drainage is performed in the same well for a long time, and the flow path of groundwater 17 and the first well 81 or second well 82 from which groundwater 17 is discharged are removed. There is a high possibility that foreign matter has accumulated in the In this case, intermittent backwashing is automatically performed, so there is no need for the user to manually perform intermittent backwashing. Therefore, user convenience is improved.

Further, the operating time, which is the time during which the underground water 17 whose liquid feeding was started in S24, is flowing is measured (S27). When the operating time is longer than the first predetermined time "T1" (S39: YES), intermittent backwashing is performed (S45). When the operating time exceeds the first predetermined time "T1", intermittent backwashing is automatically performed, so there is no need for the user to manually perform intermittent backwashing. Therefore, user convenience is improved.

Furthermore, the pumping and drainage of the groundwater 17 started in S27 is stopped in S43. While pumping and draining of the groundwater 17 is stopped, when a predetermined time has come (S22: YES), intermittent backwashing is performed (S45). In this case, backwashing is performed while pumping and draining of groundwater 17 is stopped. Therefore, it is possible to prevent backwashing from being performed during the time when the underground water 17 is being pumped and drained.

In addition, if it is determined that the operating time is longer than the first predetermined time "T1" (S39: YES), and if the pumping and drainage of the groundwater 17 started in S24 is stopped (S43), Backwashing is performed (S45). In addition, if the operating time is longer than the second predetermined time "T2" which is longer than the first predetermined time "T1" (S41: YES), the pumping and drainage of the groundwater 17 is stopped (S48), and the intermittent Backwashing is performed (S49). As described above, in this embodiment, when the first predetermined time "T1" has elapsed and the pumping and drainage of the groundwater 17 is stopped, intermittent backwashing is performed (S45). Since intermittent backwashing is performed when the underground water 17 is not being pumped or drained, the operation of pumping and draining the ground water is prevented from being disturbed. On the other hand, if the pumping and draining of the groundwater 17 is not stopped even after the first predetermined time "T1" has elapsed, and the second predetermined time "T2" has elapsed (S41: YES), the pumping and draining of the groundwater 17 is not stopped. is stopped (S48), and intermittent backwashing is forcibly performed (S49). Therefore, even after the second predetermined time "T2" has elapsed, the amount of foreign matter and the like that accumulates in the well and the flow path can be reduced compared to the case where intermittent backwashing is not performed.

In addition, when the groundwater 17 is pumped and drained again in S24 after intermittent backwashing is performed in S45 or S49, intermittent backwashing is performed in the first well 81 and the second well 82. The groundwater 17 is pumped from the same well as the well from which the groundwater 17 was pumped when the groundwater 17 was pumped. In this case, of the first well 81 and the second well 82, the well from which underground water was pumped before intermittent backwashing becomes the well from which drainage is performed after intermittent backwashing. In addition, the well from which groundwater was drained before intermittent backwashing becomes the well from which groundwater is pumped after intermittent backwashing. Therefore, compared to the case where water is always pumped from one of the first well 81 and the second well 82 and water is always drained to the other well, the water pumping and drainage from the first well 81 and the second well 82 is The load will be better balanced. Therefore, it is possible to reduce the possibility that foreign matter and the like will continue to accumulate in a well that is constantly drained. Further, since one of the pumps 151 of the first well 81 and the pump 152 of the second well 82 is not continuously used, the service life of the pumps 151 and 152 is extended.

In the above embodiment, the groundwater utilization system 1 is an example of the "backwash system" of the present invention, and the CPU 581 that performs the process of S24 is an example of the "groundwater control means" of the present invention. The CPU 581 that performs the processing in S45 and S49 is an example of the "intermittent backwashing means" of the present invention. The CPU 581 that performs the process of S38 is an example of the "increase amount determining means" of the present invention. The CPU 581 that performs the process of S27 is an example of the "operating time measuring means" of the present invention. The CPU 581 that performs the process of S39 is an example of the "first operation time determining means" of the present invention. The CPU 581 that performs the process of S22 is an example of the "time determination means" of the present invention. The CPU 581 that performs the process of S41 is an example of the "second operation time determining means" of the present invention. The CPU 581 that performs the process of stopping the pumping and drainage of the groundwater 17 in S48 and the process of S49 is an example of the "forced backwashing means" of the present invention. The process in S24 is an example of a "groundwater control step." The processing in S45 and S49 is an example of an "intermittent backwashing step." The process of S27 is an example of the "driving time measuring step" of the present invention. The process of S39 is an example of the "first operation time determination step" of the present invention. The process in S41 is an example of the "second operation time determination step" of the present invention. The process of stopping pumping and draining of the groundwater 17 in S48 and the process of S49 are examples of the "forced backwash step" of the present invention. The CPU 581 is an example of the "computer" of the present invention.

Note that the present invention is not limited to the above-described embodiments, and various changes are possible. For example, the first control means that controls the supply of groundwater 17 to the heat exchanger 50 and the second control means that controls the supply of the liquid 18 to the heat exchanger 50 are integrated into one component, the CPU 581. However, it is not limited to this. The first control means that controls the supply of groundwater 17 to the heat exchanger 50 and the second control means that controls the supply of the liquid 18 to the heat exchanger 50 may be separate CPUs. The separate CPUs may be located in separate control panels.

Furthermore, the pumps 151 and 152 were controlled based on the temperature difference between the first temperature and the second temperature, and the flow rate of the groundwater 17 was adjusted, but the flow rate of the groundwater 17 was not adjusted based on the temperature difference. Good too. Further, the pumps 151 and 152 may be pumps that cannot adjust the flow rate of the groundwater 17 and pump the groundwater 17 at a constant flow rate.

Although the pump 579 is controlled and the flow rate of the liquid 18 is adjusted based on the temperature difference between the third temperature and the fourth temperature, the flow rate of the liquid 18 does not need to be adjusted based on the temperature difference. Further, the pump 579 may be a pump that cannot adjust the flow rate of the liquid 18 and pumps the liquid 18 at a constant flow rate.

In addition, the pressure of the groundwater 17 flowing into the heat exchanger 50 is measured (S34), and if the measured pressure is equal to or higher than a predetermined pressure (S35: YES), it is notified (S36), but this is not limited to this. Not done. For example, the pressure of groundwater 17 flowing out from heat exchanger 50 may be measured. Even in this case, if the heat exchanger 50 is clogged with foreign matter, the pressure of the groundwater flowing into the heat exchanger increases to a predetermined pressure or higher. Since the user is notified when the pressure is equal to or higher than the predetermined pressure, the user can easily determine that it is time to replace the heat exchanger 50. Therefore, user convenience is improved. Further, in S35, it is only necessary to determine whether or not clogging has occurred in the heat exchanger 50 based on the pressure of the groundwater 17, and other methods of the above embodiments may be used. For example, in S34, the pressure of groundwater 17 flowing into the heat exchanger 50 and the pressure of groundwater 17 flowing out are measured, and the pressure of groundwater 17 flowing into the heat exchanger 50 and the pressure of groundwater 17 flowing out are measured. It may be determined whether or not clogging has occurred in the heat exchanger 50 based on the pressure difference between the heat exchanger 50 and the pressure (S35). For example, if the pressure difference is greater than or equal to a predetermined value (for example, 0.1 Mpa) (S35: YES), a notification is issued (S36).

Further, when the notification is made in S36, the notification device 589 is turned on, but the invention is not limited to this. For example, a sound may be emitted from the operation unit 588 or the alarm 589. Further, the alarm 589 may not be provided. Further, the pressure of the groundwater 17 flowing into or out of the heat exchanger 50 may not be measured.

Further, although the case portion 590 is provided with the heat insulating material 598, the present invention is not limited thereto. The heat insulating material 598 may not be provided. Further, the heat exchanger 50 may be provided inside the case portion 590, and other components such as the control panel 580 may be provided outside the case portion 590. For example, the CPU 581 may be provided on the outer surface of the case portion 590. In this case, as an example, as shown by the dotted line in FIG. 8, a storage section 986 that stores the control panel 580 including the CPU 581 may be provided, and the storage section 986 may be fixed to the outer surface of the case section 590. In this case, the control panel 580 inside the case portion 590 may not be provided. Even when the CPU 581 is provided on the outer surface of the case part 590, the CPU 581, which controls the supply of the underground water 17 and the liquid 18 to the heat exchanger 50, the heat exchanger 50, and the case part 590 form one heat exchanger. Since it is provided in the unit 5, the cost of installation work can be reduced.

Note that the position of the control panel 580 disposed on the outside or inside of the case portion 590 is not limited to the case shown in FIG. 8. Furthermore, although the storage section 986 that houses the control panel 580 and the operation section 588 are provided separately, the present invention is not limited thereto. For example, the operating section 588 may be arranged on the surface of the storage section 986.

Moreover, the CPU 581 and the heat exchanger 50 only need to be provided in one heat exchange unit 5, and other parts do not need to be included in the heat exchange unit 5. Further, although the outdoor unit 20, which is a device including the heat pump 2, is placed outdoors in the building 78, the device including the heat pump 2 may be placed indoors in the building 78. All or part of the outdoor unit 20 may be integrally or closely connected to the case portion 590. Further, a plurality of outdoor units 20 may be connected to the case portion 590 of one heat exchange unit 5.

Moreover, although the groundwater 17 discharged from the outlets 551 and 552 of the flow paths 508 and 509 is discharged to the outside via the drainage drain pan 599, the present invention is not limited thereto. For example, the drain pan 599 may not be provided. In this case, a flow path connected to the flow paths 508 and 509 may extend to the outside of the case portion 590, and the groundwater 17 may be drained.

Further, the process of S22 may not be executed. Further, in the process of S27, the driving time may not be measured. The process of S39 may not be executed. Further, in S37, the water level of the groundwater 17 may not be detected. The process of S38 may not be executed. Backwashing does not need to be performed automatically, and may be performed when a user inputs a backwashing instruction to heat exchange unit 5 via operation section 588.

Further, when intermittent backwashing is performed in S45 and S49, the groundwater 17 is discharged to the drainage drain pan 599, but the present invention is not limited thereto. For example, instead of backwashing in the backwash direction H6, the groundwater 17 may be flowed in the first direction H1. That is, when intermittent backwashing is performed, the groundwater 17 may be pumped up from the first well 81 and returned to the second well 82 . Furthermore, for example, instead of performing intermittent backwashing in the backwash direction H5, the groundwater 17 may be caused to flow in the second direction H2. That is, when intermittent backwashing is performed, the groundwater 17 may be pumped from the second well 82 and returned to the first well 81. In this case, intermittent backwashing is performed in all channels 501 to 506 and 901 to 904 where groundwater 17 flows in the first direction H1 and the second direction H2.

Further, when intermittent backwashing is performed in S45 and S49, intermittent backwashing is performed in the backwash direction H6 for an initial predetermined time or a predetermined number of times, and then intermittent backwashing is performed in the first direction H1. It may be possible to switch to backwashing. Alternatively, intermittent backwashing may be performed in the backwash direction H5 for an initial predetermined time or a predetermined number of times, and then switched to intermittent backwashing in the second direction H2. In this case, immediately after backwashing is started, there is a high possibility that foreign matter is mixed in the groundwater 17 being discharged, so drainage can be performed from the drainage drain pan 599. After that, the groundwater 17 can be returned to the first well 81 or the second well 82.

Further, although the water level sensor 971 was provided above the water surface 811 and the water level sensor 972 was provided above the water surface 821, the present invention is not limited thereto. For example, the water level sensor 971 may be placed in the groundwater 17 of the first well 81, and the water level sensor 972 may be placed in the groundwater 17 of the second well 82. In this case, the water level sensors 971 and 972 detect the water level of the groundwater 17 by, for example, measuring water pressure (S37).

Further, the configuration of each flow path is an example, and is not limited to the case of this embodiment. Various flow paths different from this embodiment may be configured by combining two-way valves and three-way valves. For example, when the groundwater 17 flows in the first direction H1 shown in FIG. 1 and when the groundwater 17 flows in the second direction H2, the direction of the groundwater 17 flowing into the heat exchanger 50 is opposite. The flow path may be configured so that the underground water 17 flowing into the heat exchanger 50 always flows in the same direction. Further, the air bleed valve 942 does not need to be provided because air will not enter the flow path if air is bleed during the trial run. Further, the on-off valves 569 and 570 may be electrically operated valves controlled by the CPU 581. Further, the electric valves 561 to 568 may be on-off valves that can be opened and closed manually. Further, the safety valve 943 and the air bleed valves 941 and 942 may be operated under the control of the CPU 581.

Further, although the case portion 590 is provided, the present invention is not limited thereto. Case portion 590 may not be provided. That is, the heat exchange unit 5 does not need to be unitized.

In addition, when intermittent backwashing is performed, the groundwater 17 flows through the heat exchanger 50 (see backwash direction H5 and backwash direction H6 in FIG. 4), but the groundwater 17 does not flow through the heat exchanger 50. Good too. For example, when intermittent backwashing is performed, the groundwater 17 may flow not in the backwash direction H5 in FIG. 4 but in the backwash direction H7 in FIG. 8 . When the groundwater 17 flows in the backwash direction H7, the CPU 581 opens at least the electric valves 565 and 568, closes at least the electric valves 562 and 566, and drives the pump 152. In this case, the groundwater 17 is pumped up from the second well 82 and discharged to the wastewater drain pan 599 via the channel 903, the channel 505, a part of the channel 504, the channel 509, and the outlet 552. The groundwater 17 discharged into the drainage drain pan 599 is discharged to the outside of the heat exchange unit 5 via the discharge channel 515.

Furthermore, when intermittent backwashing is performed, the groundwater 17 may flow in the backwash direction H8 in FIG. 8 instead of in the backwash direction H6 in FIG. 4 . When the groundwater 17 flows in the backwash direction H8, the CPU 581 opens at least the electric valves 563 and 567, closes at least the electric valves 561 and 564, and drives the pump 151. In this case, the groundwater 17 is pumped up from the first well 81 and discharged to the drainage drain pan 599 via the flow path 901, the flow path 502, a part of the flow path 501, the flow path 508, and the outlet 551. The groundwater 17 discharged into the drainage drain pan 599 is discharged to the outside of the heat exchange unit 5 via the discharge channel 515.

Further, as shown in FIG. 8, a water intake port 982 connected to the flow path of the groundwater 17 may be provided, and a faucet 983 may be attached to the water intake port 982. In the example shown in FIG. 8, a flow path 981 connected to the flow paths 508 and 509 extends into the case portion 590. The water intake port 982 is arranged on the outside of the case portion 590. A generator 984 can be connected to the heat exchange unit 5 . A faucet 983 can be attached to the water intake 982 . For example, in the event of a disaster, power can be supplied to the heat exchange unit 5 by the generator 984. In this case, the heat exchange unit 5 can drive the pump 151 or 152 by the power supplied from the generator 984, pump up the groundwater 17 from the wells 81 and 82, and supply the groundwater 17 from the faucet 983 as disaster water. can. Note that the water intake port 982 may be connected to any flow path of the groundwater 17, and the flow path to which the water intake port 982 is connected is not limited. Further, an on-off valve may be provided to switch between the flow path toward the outflow ports 551 and 552 and the flow path 981 toward the water intake port 982. Further, the flow paths 508 and 509 may be connected to the flow path 981 without providing the outlet ports 551 and 552. In this case, the waste water flowing through the channels 508 and 509 may be discharged to the outside of the heat exchange unit 5 via the water intake port 982 or the faucet 983. Further, when it is not a disaster, the power source supplied to the heat exchange unit 5 is not limited, and power may be supplied from the generator 984 or from the power grid. The faucet 983 may be detachable from the water intake port 982.

Furthermore, even if it is determined that the amount of increase in the water level of the groundwater 17 in the well from which the groundwater 17 is discharged among the first well 81 and the second well 82 is equal to or greater than the predetermined amount of increase (S38: YES), Although groundwater 17 continued to be discharged into the well, the present invention is not limited to this. For example, as in the modification shown in FIG. 9, it is determined that the amount of rise in the water level of the groundwater 17 in the well from which the groundwater 17 is discharged is greater than or equal to the predetermined amount of rise in the first well 81 and the second well 82. If so (S38: YES), the groundwater 17 may be discharged to the outside of the first well 81 and the second well 82 (S52).

For example, in a state where the groundwater 17 is flowing in the first direction H1 in FIG. 1, if it is determined that the amount of rise in the water level of the groundwater 17 in the second well 82 is equal to or greater than the predetermined amount of rise "K21" (S38: YES), the groundwater 17 may be flowed in the same direction as the backwash direction H6 in FIG. 4 (S52). In this case, the groundwater 17 is discharged to the outside of the first well 81 and the second well 82 via the outlet 552, the drainage drain pan 599, and the discharge channel 515 (S52). In this case, the opening and closing of the electric valves 561 to 568 are controlled in the same way as in the case of flowing the groundwater 17 in the backwash direction H6 (S52). Since the groundwater 17 continues to flow through the heat exchanger 50, heat exchange by the heat exchanger 50 can continue.

For example, when it is determined that the amount of rise in the water level of the groundwater 17 in the first well 81 is equal to or greater than the predetermined amount of rise "K11" in a state where the groundwater 17 is flowing in the second direction H2 in FIG. S38: YES), the groundwater 17 may be flowed in the same direction as the backwash direction H5 in FIG. 4 (S52). In this case, the groundwater 17 is discharged to the outside of the first well 81 and the second well 82 via the outlet 551, the drainage drain pan 599, and the discharge channel 515 (S52). In this case, the opening and closing of the electric valves 561 to 568 are controlled in the same way as in the case of flowing the groundwater 17 in the backwash direction H5 (S52). Since the groundwater 17 continues to flow through the heat exchanger 50, heat exchange by the heat exchanger 50 can continue. Note that S52 is not intermittent backwashing.

After the process of S52 is executed, the process advances to S40. In the case of this modification, if it is determined that the amount of rise in the water level of the groundwater 17 in the well from which the groundwater 17 is discharged out of the first well 81 and the second well 82 is greater than or equal to the predetermined amount of rise (S38: YES), the groundwater 17 is discharged to the outside of the first well 81 and the second well 82 (S52). Therefore, it is possible to prevent the amount of increase in the water level of the groundwater 17 in the well from which the groundwater 17 is discharged from continuing to increase beyond a predetermined amount of increase. Further, it is possible to suppress an increase in the amount of foreign matter and the like that accumulates in the first well 81 or the second well 82 from which the groundwater 17 is discharged. Moreover, it becomes possible to operate the groundwater utilization system 1 without stopping water pumping from the first well 81 or the second well 82. Therefore, unlike the case of FIG. 10 described later, the pumped groundwater 17 can be discharged to the outside of the first well 81 and the second well 82 without stopping the air conditioning operation by heat exchange. Note that the CPU 581 that performs the process of S52 is an example of the "emission control means" of the present invention.

Furthermore, even if it is determined whether the rise in the water level of the groundwater 17 in the well from which the groundwater 17 is discharged among the first well 81 and the second well 82 is equal to or greater than the predetermined rise (see FIG. (S38: YES), the heating and cooling operation continued until the stop instruction signal was received in S42. Then, in S42, a stop instruction signal was received (S42 in FIG. 7: YES), and after the heating and cooling was stopped (S43 in FIG. 7), intermittent backwashing was executed (S45 in FIG. 6), but this is not limited to Not done. For example, as in the modified example shown in FIG. 10, it is determined that the amount of rise in the water level of the groundwater 17 in the well from which the groundwater 17 is discharged from the first well 81 and the second well 82 is greater than or equal to the predetermined amount of rise. If so (S38: YES), the heating and cooling may be stopped immediately (S48), and intermittent backwashing may be performed (S49). In this case, the process of S52 in FIG. 9 may not be executed. Note that in FIGS. 9 and 10, processes similar to those in FIG. 7 are indicated by the same reference numerals, and detailed explanations will be omitted.

Further, when the pressure of the groundwater 17 acquired in S34 is equal to or higher than the predetermined pressure (S35 in FIG. 7: YES), notification is performed (S36 in FIG. 7), but the present invention is not limited to this. Clogging of the heat exchanger 50 may be determined and notified by a method of determining heat exchange performance based on average temperature difference or the like. FIG. 11 is a modification of FIG. 7. In FIG. 11, the process of S34 in FIG. 7 is omitted. Then, after the process in S33, the process in S351 is executed, and clogging is determined.

In S351, an average temperature difference is calculated based on the temperature at which the groundwater 17 flows into the heat exchanger 50, the temperature at which the groundwater 17 flows out, the temperature at which the liquid 18 flows in, and the temperature at which the liquid 18 flows out. Based on the average temperature difference, it is determined whether or not the heat exchanger 50 is clogged. If it is determined that the heat exchanger 50 is clogged (S351: YES), a notification is issued (S36). If it is determined that the heat exchanger 50 is not clogged (S351: NO), the process proceeds to S37. In addition, in this embodiment, the temperature T01 at which the groundwater 17 flows into the heat exchanger 50 is the first temperature measured in S28, and the temperature T02 at which the groundwater 17 flows out is measured in S29. The second temperature, temperature T03 at which the liquid 18 flows in, is the third temperature measured in S31, and the temperature T04 at which the liquid 18 flows out is the fourth temperature measured in S32.

In S351, for example, if the average temperature difference ΔT11 is a predetermined temperature difference (for example, a difference of 10 degrees), it may be determined that there is clogging. Various calculation methods can be used to calculate the average temperature difference ΔT11 in S351. For example, the average temperature difference ΔT11 may be an arithmetic average temperature difference as shown in equation (1) below.
ΔT11=(|T01-T04|+|T02-T03|)/2...Formula (1)
Further, the average temperature difference ΔT11 may be a logarithmic average temperature difference.

Further, in S351, when determining whether or not clogging has occurred in the heat exchanger 50 based on the average temperature difference ΔT11, the following equation (2) may be used.
KA=Q/ΔT11...Formula (2)
K: Heat transfer rate [W/{(m^2)×K}]
A: Heat transfer area [m^2]
Q: Heat exchange amount [W]
ΔT11: Average temperature difference [K]
Q=ρCVΔT12
ΔT12=|T04-T03|
ρ: Density [kg/(m^3)] (e.g. liquid 18)
C: Specific heat [J/(kg・K)] (e.g. liquid 18)
V: Flow rate [(m^3)/s] (for example, liquid 18)
ΔT12: Temperature difference [K] (for example, liquid 18)
In this modification, when KA becomes less than or equal to a predetermined value, it is determined that there is clogging (S351: YES), and a notification is issued (S36).

Note that the following equation (3) may be used instead of equation (1).
ΔT11=(|T01-T03|+|T02-T04|)/2...Formula (3)
As an example, if the groundwater 17 flows in the first direction H1 (see FIG. 1) and the liquid 18 flows in the direction H3, in the heat exchanger 50, the groundwater 17 and the liquid 18 flow in opposite directions. Become. In the case of counterflow, the above equation (1) may be used. Further, when the groundwater 17 flows in the second direction H2 (see FIG. 1) and the liquid 18 flows in the direction H3, in the heat exchanger 50, the groundwater 17 and the liquid 18 flow in the same direction, resulting in "parallel flow". . In the case of parallel flows, the above formula (3) may be used. Note that the above is an example of calculating the average temperature difference, and the average temperature difference may be calculated using other methods, or other conditions may be added.

When the heat exchanger 50 is clogged with foreign matter, the average temperature difference changes. In this modification, when it is determined that the heat exchanger is clogged based on the average temperature difference (S351: YES), a notification is given (S36), so the user can replace the heat exchanger 50. You can easily tell when the time has come. Therefore, user convenience is improved. Further, since there is no need to determine clogging based on pressure, it is possible to eliminate the pressure sensors 576 and 577, and costs can be reduced.

Furthermore, although a system in which the heat exchange unit 5 is provided has been described, the present invention is not limited thereto. For example, the components included in the heat exchange unit 5 do not need to be combined into one unit. Case portion 590 may not be provided. Furthermore, although a system that performs heat exchange has been described as an example of a system that performs intermittent backwashing, the present invention is not limited to the case of heat exchange. The application is not limited as long as it is a system that pumps groundwater 17 from one of the first well 81 and second well 82 and discharges the groundwater 17 to the other well through a flow path. For example, groundwater 17 is pumped up from one of the first well 81 and second well 82, and a portion of the groundwater 17 is used for predetermined purposes (for example, various uses such as washing vegetables and drinking). However, the system may also be such that the other groundwater 17 is discharged to the other well. Alternatively, the system may be such that the groundwater 17 is pumped up from one of the first well 81 and the second well 82, purified by a purification device, and then discharged to the other well. In addition, a system (i.e., It may also be a system that simply moves groundwater 17 from one well to another. For example, if the purpose is to wash vegetables or purify the groundwater 17, the washing of vegetables or the purification of the groundwater 17 is started in the process of S26, and the washing of vegetables or the purification of the groundwater 17 is stopped in S43 and S48. Good too. Further, for example, S25, S28 to S33, and other unnecessary processes may not be executed.

1 Groundwater utilization system 2 Heat pump 5 Heat exchange units 11-14,501-514,901-904 Flow paths 16, 18 Liquid 17 Groundwater 50 Heat exchanger 81 First well 82 Second well 151,152,579 Pump 210,580 Control panel 571, 572, 573, 574 Temperature sensor 575 Flow meter 576, 577 Pressure sensor 211, 581 CPU
589 Alarm 590 Case part 598 Insulating material 971, 972 Water level sensor

Claims (7)

Groundwater control means for pumping groundwater from one of the first well and the second well and discharging the groundwater to the other well through a flow path;
Intermittent backwashing means for performing intermittent backwashing that washes the first well or the second well by intermittently flowing the groundwater in the opposite direction ;
Operating time measuring means for measuring the operating time, which is the time during which the groundwater control means flows the groundwater;
a first operation time determination means for determining whether the operation time measured by the operation time measurement means is equal to or longer than a first predetermined time;
a second operation time determination means for determining whether the operation time measured by the operation time measurement means is equal to or longer than a second predetermined time that is longer than the first predetermined time;
Forcing the intermittent backwashing to be performed by stopping pumping and drainage of the groundwater by the groundwater control means when the second operating time determining means determines that the operating time is equal to or longer than the second predetermined time. backwashing means and
Equipped with
The intermittent backwash means is configured to stop pumping and draining of the groundwater by the groundwater control means when the first operation time determination means determines that the operation time is equal to or longer than the first predetermined time. A backwashing system characterized in that the intermittent backwashing is performed when Of the first well and the second well, the water level of the groundwater in the well from which the groundwater is discharged is increased by an amount of increase determining means for determining whether the amount of increase in the water level of the groundwater is equal to or greater than a predetermined amount of increase;
2. The intermittent backwashing means performs the intermittent backwashing when the rise amount determining means determines that the rise amount of the water level is equal to or greater than a predetermined rise amount. backwash system. A time determination means for determining whether a predetermined time has arrived while the pumping and drainage of the groundwater by the groundwater control means is stopped;
3. The backwash system according to claim 1 , wherein the intermittent backwash means performs the intermittent backwash when the time determination means determines that a predetermined time has arrived. When pumping and draining the groundwater again after the intermittent backwashing is performed by the intermittent backwashing means, the groundwater control means controls the intermittent backwashing between the first well and the second well. The backwash system according to any one of claims 1 to 3 , wherein the groundwater is pumped from the well where backwashing has been performed. If the amount of increase determination means determines that the amount of increase in the water level of the groundwater in the well from which the groundwater is discharged is equal to or greater than a predetermined amount of increase, the outside of the first well and the second well 3. The backwash system according to claim 2, further comprising discharge control means for discharging the groundwater. A groundwater control step of pumping groundwater from one of the first well and the second well and discharging the groundwater to the other well through a flow path;
an intermittent backwashing step of performing intermittent backwashing of washing the first well or the second well by intermittently flowing the groundwater in a reverse direction ;
an operation time measuring step of measuring an operation time that is the time for flowing the groundwater in the groundwater control step;
a first operating time determining step of determining whether the operating time measured in the operating time measuring step is equal to or longer than a first predetermined time;
a second operating time determining step of determining whether the operating time measured in the operating time measuring step is equal to or longer than a second predetermined time that is longer than the first predetermined time;
If it is determined in the second operation time determination step that the operation time is equal to or longer than the second predetermined time, stopping pumping and drainage of the groundwater in the groundwater control step and forcing the intermittent backwashing to be performed. backwash step and
Equipped with
The intermittent backwashing step is performed when it is determined in the first operation time determination step that the operation time is equal to or longer than the first predetermined time, and when the pumping and drainage of the groundwater by the groundwater control step is stopped. A backwashing method characterized in that the intermittent backwashing is performed when In the backwash system computer,
A groundwater control step of pumping groundwater from one of the first well and the second well and discharging the groundwater to the other well through a flow path;
an intermittent backwashing step of performing intermittent backwashing of washing the first well or the second well by intermittently flowing the groundwater in a reverse direction ;
an operation time measuring step of measuring an operation time that is the time for flowing the groundwater in the groundwater control step;
a first operating time determining step of determining whether the operating time measured in the operating time measuring step is equal to or longer than a first predetermined time;
a second operating time determining step of determining whether the operating time measured in the operating time measuring step is equal to or longer than a second predetermined time that is longer than the first predetermined time;
If it is determined in the second operation time determination step that the operation time is equal to or longer than the second predetermined time, stopping pumping and drainage of the groundwater in the groundwater control step and forcing the intermittent backwashing to be performed. backwash step and
run the
In the intermittent backwashing step, when it is determined in the first operation time determination step that the operation time is equal to or longer than the first predetermined time, and the pumping and drainage of the groundwater by the groundwater control step is stopped. A backwash program for performing said intermittent backwash when

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