JP2015025583A - Heat pump hot water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump hot water supply system capable of finding occurrence of a failure in a defrosting on-off valve as early as possible without adding new means such as an operation switch.SOLUTION: Before executing a normal operation control to boil water by actuation of a heat pump, a defrosting solenoid valve check control (SUB1, SUB3) is executed as an initial control to force a state of a defrosting solenoid valve to be switched over between an open state and a closed state by turning on power. In a normal operation, upon satisfaction of a condition for starting defrosting an evaporator, high-temperature refrigerant is directly supplied via a bypass passage from a compressor to the evaporator to defrost the evaporator by switching the state of the defrosting solenoid valve to the open state. The initial control is executed to switch the state of the defrosting solenoid valve over between the open state and the closed state regardless of whether the defrosting start condition is satisfied. It is thereby possible to confirm whether the defrosting solenoid valve normally operates in the open/closed state depending on presence/absence of a valve opening/closing sound.

Description

  The present invention relates to a heat pump hot water supply apparatus, and more particularly to a technique that enables early confirmation as to whether or not a defrosting electromagnetic on-off valve for performing a defrosting operation normally opens and closes.

  Conventionally, a refrigerant circulation circuit in which a compressor, a condenser, a pressure reducing means, and an evaporator are connected in order by a refrigerant circulation pipe, and water supplied to the condenser by a feed water pump is heated to a target with a high-pressure refrigerant compressed by the compressor. 2. Description of the Related Art A heat pump hot water supply apparatus that includes a hot water supply circuit that is used for hot water supply by heat exchange heating to temperature is known. In such a heat pump hot water supply device, the evaporative heat exchanger usually frosts at a time when the outside air temperature is low, and heat exchange cannot be performed. Therefore, it is necessary to perform a defrosting operation to melt the frost attached to the evaporator. is there. In order to enable such a defrosting operation, a bypass path is provided that branches from the discharge side of the compressor, bypasses the condenser and the decompression means, and joins to the inlet side of the evaporator. A defrosting solenoid valve is interposed, and when defrosting is required, the defrosting solenoid valve is opened so that a high-temperature refrigerant can be introduced from the compressor into the evaporator to melt the frost. (See, for example, paragraph 0071 of Patent Document 1).

Japanese Patent No. 3925433

  However, in the conventional heat pump hot water supply apparatus, even if the defrosting solenoid valve is out of order, the occurrence of the failure may not be detected at an early stage, which may cause a delay in countermeasures. That is, the defrosting operation is executed only when the defrosting operation start condition is established, for example, the outside air temperature is in a predetermined low temperature state and the temperature of the evaporator is lowered to a predetermined temperature or less. Until then, the defrosting solenoid valve is kept closed. For this reason, even if it is in an open failure state (a failure state in which the valve is stuck and does not open even if the opening operation is controlled), if the defrosting operation start condition is not satisfied, the opening operation is not performed. As a result, the detection of the occurrence of a failure in the defrosting solenoid valve is delayed. Moreover, frost formation is unlikely to occur in summer, and failure detection will be delayed more and more.

  As a countermeasure, it is conceivable to provide an operation switch for switching the opening / closing of the defrosting electromagnetic valve from the control so that the defrosting electromagnetic valve can be opened / closed independently by turning on the operation switch. However, even if such an operation switch is provided, the operation is difficult or the cost is increased. In other words, the heat pump part is usually installed outdoors, and even if an operation switch is provided on the control board protected in the housing, it becomes difficult to operate, but an operation switch is provided at a position where it can be easily operated by predetermined electrical equipment. As a result, the cost increases.

  The present invention has been made in view of such circumstances, and an object of the present invention is to detect the occurrence of a failure in the defrosting on-off valve at an early stage without adding means such as an operation switch. An object of the present invention is to provide a heat pump hot water supply apparatus.

  In order to achieve the above object, in the present invention, a compressor, a condenser, a decompression means, and a heat pump unit in which an evaporator is connected in order by a refrigerant circulation pipe, and refrigerant discharged from the compressor are supplied to the evaporator. On the other hand, a bypass path that bypasses and supplies the pressure reducing means, a normally-closed opening / closing control valve interposed in the bypass path, and the opening / closing control valve is opened when the defrosting start condition for the evaporator is satisfied. Thus, the following specific matters are provided for a heat pump hot water supply apparatus including a control means for defrosting operation control for introducing a high-temperature refrigerant from a compressor into an evaporator. In other words, the control means is configured to perform initial control for opening / closing conversion of the open / close control valve when the power is turned on regardless of whether the defrost start condition is satisfied or not (claim 1).

  In the case of the present invention, when the power is turned on by executing the initial control, first, the open / close control valve is forcibly converted to open / close first. It becomes possible to confirm whether or not. That is, for example, if the power is turned on at the time of installation or maintenance of the apparatus, it is possible to confirm whether the open / close control valve normally opens and closes without waiting for the defrost start condition to be satisfied. In other words, it can be determined that the valve is operating normally if there is a valve opening / closing sound, and it can be determined that the valve is stuck in the closed state or the open state and is in an abnormal state if there is no valve opening / closing sound. become. As described above, it is possible to detect the occurrence of a failure of the defrosting on / off control valve at an early stage without newly adding means such as an operation switch.

  In the heat pump hot water supply apparatus of the present invention, the control means may be configured not to perform the initial control when a predetermined set time elapses after the power is turned on (Claim 2). By doing so, the forced opening / closing conversion of the open / close control valve is executed at the beginning of the installation by turning on the power. Can be done. On the other hand, if a predetermined set time elapses after the early confirmation, the forced open / close conversion of the open / close control valve is not executed, and no valve open / close sound is generated even when the power is turned on again. As a result, it is possible to avoid the occurrence of situations such as causing the user to have questions such as making a sound every time the power is turned on, or causing anxiety that it is a malfunction. become.

  As described above, according to the heat pump water heater of the present invention, when the power is turned on by the execution of the initial control, the open / close control valve is first forcibly opened / closed. Whether or not the opening / closing control valve normally opens and closes can be confirmed based on the presence or absence. That is, if the power is turned on at the time of installation or maintenance of the apparatus, it is possible to check whether the open / close control valve normally opens and closes without waiting for the defrost start condition to be satisfied. For this reason, it becomes possible to detect the occurrence of a failure of the defrosting on / off control valve at an early stage without newly adding means such as an operation switch.

  According to the heat pump hot water supply apparatus of the second aspect, the control means is configured such that the initial control is not performed when a predetermined set time has elapsed after the power is turned on. Since the forced open / close conversion is executed, it is possible to confirm whether the open / close control valve normally opens / closes by the generation of the valve open / close sound. When the time has elapsed, the forced open / close conversion of the open / close control valve is not executed, and the valve open / close sound can be prevented from being generated even when the power is turned on again. As a result, it is possible to avoid the occurrence of situations such as causing the user to have questions such as making a sound every time the power is turned on, or causing anxiety that it is a malfunction. become.

It is a schematic diagram of the heat pump hot-water supply apparatus which concerns on embodiment of this invention. It is a front view which shows the example of the installation state of the heat pump hot-water supply apparatus of FIG. It is a basic control flowchart concerning operation control of a heat pump hot-water supply apparatus. It is a flowchart of the defrost electromagnetic valve check control of 1st Embodiment. It is a flowchart which shows the example of normal driving | operation control. It is a flowchart of the defrost electromagnetic valve check control of 2nd Embodiment. It is a flowchart which shows the example of the normal driving control applied to 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show a heat pump hot water supply apparatus according to an embodiment of the present invention. This heat pump hot-water supply device is a combination of a heat pump unit 1 and a hot water storage unit 2, and can heat and heat the water in the hot water storage unit 2 using a refrigeration cycle. As shown in FIG. 1, the heat pump unit 1 circulates a refrigerant through a compressor 11, a condensation heat exchanger (condenser) 12, an expansion valve 13 as a decompression unit, and an evaporation heat exchanger (evaporator) 14. The pipes 15 are connected in order. As the refrigerant to be circulated in the heat pump unit 1, an appropriate HC refrigerant such as propane or CO 2 can be employed. The hot water storage unit 2 includes a hot water storage tank 21, a water circulation pipe 22 that circulates hot water stored in the hot water storage tank 21, and the condensation heat exchanger, and water from the bottom of the hot water storage tank 21 for the condensation heat exchange. The water supply pump 23 is pumped to the vessel 12 and led from the condensation heat exchanger 12 to the top of the hot water storage tank 21 after heating. The heat pump unit 1 and the hot water storage unit 2 are controlled by the controllers 3 and 3a so that water is heated to the target boiling temperature in the condensation heat exchanger 12 and stored in the hot water storage tank 21. . In addition, it is not restricted to what was illustrated in FIG. 2, The heat pump unit 1 and the hot water storage unit 2 can also be accommodated in one housing | casing.

  The operation of the heat pump unit 1 will be briefly described. When compressed by the compressor 11, high-temperature refrigerant is discharged from the compressor 11 to the refrigerant circulation pipe 15, and the discharge temperature is detected and detected by the discharge temperature sensor 16. The discharge temperature is output to the controller 3. The condensation heat exchanger 12 is configured such that a part of the refrigerant circulation pipe 15 is passed through the inside, and a part of the water circulation pipe 22 is passed through the inside from the reverse direction to exchange heat therebetween. Then, the high-temperature refrigerant discharged from the compressor 11 to the refrigerant circulation pipe 15 and the water supplied from the bottom of the hot water storage tank 21 by the water supply pump 23 are subjected to heat exchange, and the water is converted into hot water by heat exchange heating. The refrigerant whose heat has been removed by the exchange condenses. The expansion valve 13 depressurizes the refrigerant condensed in the condensation heat exchanger 12. The operation of the expansion valve 13 is controlled by the controller 3 using the opening degree as an operation control amount. The evaporative heat exchanger 14 includes a fan 14a that blows outside air by its rotational operation, and heat is exchanged between the outside air and the refrigerant decompressed by the expansion valve 13, thereby evaporating the refrigerant. The refrigerant temperature immediately after leaving the evaporating heat exchanger 14 is detected by the evaporating heat exchanger outlet temperature sensor 17 as the evaporating heat exchanger temperature, and the detected evaporating heat exchanger outlet temperature is output to the controller 3. Become. Then, the refrigerant evaporated by heat exchange in the evaporating heat exchanger 14 is compressed again in the compressor 11 and becomes a high temperature state.

  Further, the bypass that supplies the refrigerant discharged from the compressor 11 and before entering the condensation heat exchanger 12 directly to the inlet side of the evaporation heat exchanger 14 by bypassing the condensation heat exchanger 12 and the expansion valve 13. A path 18 is provided. The bypass path 18 is provided with a defrosting electromagnetic valve 19 as an opening / closing control valve for defrosting, and this defrosting electromagnetic valve 19 is kept closed during normal operation except during defrosting operation. By performing open conversion control during the frost operation, the high-temperature refrigerant discharged from the compressor 11 can be directly supplied to the evaporating heat exchanger 14 through the bypass 18. In addition, as a bypass path for the defrosting operation of the evaporative heat exchanger 14, for example, a bypass path branched from the outlet side of the condensation heat exchanger 12, for example, and communicated with the inlet side of the evaporative heat exchanger 14 That is, a bypass path that bypasses only the expansion valve 13 is adopted, and a defrosting electromagnetic valve as an open / close control valve can be interposed in the bypass path, and the following embodiment is applied to the defrosting electromagnetic valve. You can also

  On the other hand, in the hot water storage unit 2, when the water in the hot water storage tank 21 is pumped to the condensation heat exchanger 12 by the operation of the water supply pump 23, before the heat exchange heating by the incoming water temperature sensor 24 in front of the inlet of the condensation heat exchanger 12. The detected incoming water temperature is output to the controller 3. In addition, when the hot water is heated by heat exchange by passing through the condensation heat exchanger 12, the boiling temperature is detected by the hot water temperature sensor 25 on the outlet side of the condensation heat exchanger 12, and the detected boiling temperature is determined by the controller. 3 is output. In addition, the outside air temperature is detected by the outside air temperature sensor 26 and output to the controller 3. The hot water heated by the condensation heat exchanger 12 is returned to the top side of the hot water storage tank 21 and stored, and is used for subsequent hot water supply. If the amount of hot water in the hot water storage tank 21 is reduced by hot water supply, water is supplied accordingly.

  The above-described operation control of the heat pump water heater is performed by the controller 3 or 3a that includes an MPU, a memory, and the like and in which a predetermined program is recorded in advance. As shown in FIG. 3, when the controller 3 or 3a is turned on, the defrosting electromagnetic valve check control SUB1 or SUB3 is executed by the defrosting electromagnetic valve check control means as the initial control, and then the normal operation control SUB2 or SUB4 is executed. It is executed by normal operation control means. The normal operation control SUB2 or SUB4 performs, for example, boiling control so that the water on the hot water storage unit 2 side is heated by the condensation heat exchanger 12 with the target boiling temperature as the target temperature, while the defrosting operation start condition is satisfied. Defrosting operation control is performed for the evaporative heat exchanger 14.

<First Embodiment>
In the first embodiment, when the controller 3 is turned on, the defrosting electromagnetic valve check control SUB1 is executed as initial control, and then the normal operation control SUB2 is executed. In the defrosting electromagnetic valve check control SUB1, when the power is turned on, as shown in FIG. 4, the defrosting electromagnetic valve 19 in the closed state is once converted to open and then converted back to the original closed state. The operation is controlled (step S11). And it transfers to normal operation control SUB2. FIG. 5 shows an example of the normal operation control SUB2. First, it waits until an operation start command is output (NO in step S21). If an operation start command is output (YES in step S21), a boiling operation is started (step S22). That is, as described above, in the hot water storage unit 2, the water supply pump 23 is operated to circulate the water in the hot water storage tank 21 between the condensation heat exchanger 12, while the compressor 11 is operated to condense the high-temperature and high-pressure refrigerant. The heat is supplied to the heat exchanger 12 and the water is heat-exchanged and heated in the condensation heat exchanger 12. The refrigerant condensed by heat exchange heating is decompressed and expanded by the expansion valve 13, vaporized in the evaporating heat exchanger 14, compressed again by the compressor 11, and circulated and supplied to the condensation heat exchanger 12. In order to boil up to the target boiling temperature, for example, the outside air temperature detected by the outside air temperature sensor 26 at the time of the current operation, the detected water inlet temperature detected by the water inlet temperature sensor 24, the detected discharge temperature detected by the discharge temperature sensor 16, and the target water heating Based on the temperature or the like, the rotational speed of the compressor 11 is changed and controlled so that the boiling temperature detected by the tapping temperature sensor 25 becomes the target boiling temperature, the opening degree of the expansion valve 13 is changed or controlled, or The circulating flow rate of the feed water pump 23 can be changed and controlled.

  Then, whether or not the defrosting start condition is satisfied is monitored while performing the boiling operation (NO in step S23), and if the defrosting start condition is satisfied, the defrosting operation control is started (YES in step S23). S24) The defrosting operation is executed until the return condition to the normal operation is satisfied. In the defrosting operation, the defrosting electromagnetic valve 19 is opened and converted so that the high-temperature refrigerant discharged from the compressor 11 bypasses the condensation heat exchanger 12 and the expansion valve 13 and bypasses the evaporation heat exchanger 14. The frost attached to the evaporative heat exchanger 14 is melted with this high-temperature refrigerant. Before and after the defrosting operation, operation control for adjusting the pressure in the system sandwiching the defrosting electromagnetic valve 19 (for example, operation control of the expansion valve 13) can be added.

  The above-described boiling operation and defrosting operation (steps S22 to S24) are continued until the operation stop command is output (NO in step S25). If the operation stop command is output, the process returns and enters a standby state (step NO in S21). As a defrosting start condition, the temperature of the evaporative heat exchanger 14 (for example, the evaporative heat exchanger outlet temperature detected by the evaporative heat exchanger outlet temperature sensor 17) is a predetermined set temperature at which defrosting is required due to frost formation. It can be set that it has decreased to the following. Further, defrosting is started, for example, that the differential temperature obtained by subtracting the target boiling temperature from the detected discharge temperature of the compressor 11 is equal to or lower than the set differential temperature, or that the change trend of the detected discharge temperature at that time is decreasing. It may be added to the conditions. Further, the normal operation control SUB2 in FIG. 5 is an example of normal operation control, and different operation control can be adopted.

  In the case of the first embodiment described above, when power is turned on by the defrosting electromagnetic valve check control SUB1, the defrosting electromagnetic valve 19 is first forcibly opened and closed. It can be confirmed whether or not the frost electromagnetic valve 19 is normally opened and closed. That is, if the power is turned on at the time of installation or maintenance of the apparatus (for example, an operation of inserting a power outlet), the defrosting solenoid valve 19 does not wait for establishment of the defrosting start condition (start of defrosting operation control). Since it is forcibly opened and closed, it can be confirmed whether or not the defrosting electromagnetic valve 19 is normally opened and closed. That is, if there is a valve opening / closing sound, it can be determined that the valve is operating normally, and if there is no valve opening / closing sound, it can be determined that the valve is stuck in the closed state and is in an abnormal state. From the above, it becomes possible to detect a failure of the defrosting electromagnetic valve 19 for defrosting at an early stage without newly adding means such as an operation switch.

Second Embodiment
In the second embodiment, when power is turned on by the controller 3a, the defrosting electromagnetic valve check control SUB3 (see FIG. 3) is executed as initial control, and then the normal operation control SUB4 is executed. Yes. In the defrosting electromagnetic valve check control SUB3, when the power is turned on, as shown in FIG. 6, it is determined whether the opening / closing necessity flag is “1” or “0” (step S31). If the rejection flag is “1”, similarly to the defrosting electromagnetic valve check control SUB1 of the first embodiment, the defrosting electromagnetic valve 19 in the closed state is once converted to open and then converted to the original closed state. The operation is controlled to return to (step S32). The opening / closing necessity flag is initially set to “1”, and the opening / closing necessity flag is recorded in an electrically rewritable non-volatile memory (for example, EEPROM), and the heat pump water heater is turned off. Even if it is done, the contents of the opening / closing necessity flag are not lost. On the other hand, if the opening / closing necessity flag is “0”, the opening / closing conversion (step S32) of the defrosting electromagnetic valve 19 is not performed, the process proceeds to step S33, and the opening / closing necessity flag is rewritten from “0” to “1”. Then, the process proceeds to normal operation control SUB4.

  The normal operation control SUB4 of the second embodiment compulsorily changes the opening / closing necessity flag from “1” to “normal operation control SUB2 of the first embodiment when a set time (for example, 10 hours) has elapsed since the power was turned on. A process of rewriting to “0” is added. In actual control, it may be determined as appropriate in which step of the normal operation control the forced rewriting process of the opening / closing necessity flag is performed. In the example shown in FIG. 7 as an example, first, it is determined whether or not a set time has elapsed since power-on (step S41), and until the set time has elapsed (NO in step S41), the first implementation is performed. The same operation control as the normal operation control SUB2 exemplified in the embodiment is executed (steps S43 to S47).

  That is, it waits until the operation start command is output (NO in step S43), and if the operation start command is output (YES in step S43), the boiling operation is started (step S44). Then, it is monitored whether or not the defrosting start condition is satisfied while performing the boiling operation (NO in step S45), and if the defrosting start condition is satisfied, the defrosting operation control is started (YES in step S45). S46) The defrosting operation is executed until the return condition to the normal operation is satisfied. The boiling operation or the defrosting operation (steps S44 to S47) is continued until the operation stop command is output (NO in step S47), and if the operation stop command is output, the process returns to step S41 and whether or not the set time has elapsed. This determination is repeated, and if it has not elapsed, a standby state is entered (NO in step S43).

  If the set time has elapsed since the power was turned on in step S41 (YES in step S41), the opening / closing necessity flag is forcibly rewritten from “1” to “0”, and the normal operation in steps S43 to S46 is performed. Execute control. Therefore, after that, even if the power is turned off and the power is turned on again, the normal operation control is executed without executing the forced open / close conversion (step S32) of the defrosting electromagnetic valve 19.

  In the second embodiment described above, the forced opening / closing conversion of the defrosting electromagnetic valve 19 is executed by turning on the power at the beginning of installation, so whether the defrosting electromagnetic valve 19 normally opens and closes as in the first embodiment. The confirmation of whether or not can be performed at an early stage by the occurrence of valve opening / closing sound. On the other hand, if a predetermined set time elapses after the early confirmation, the forced opening / closing conversion of the defrosting electromagnetic valve 19 is not executed, and no valve opening / closing sound is generated even when the power is turned on again. As a result, it is possible to avoid the occurrence of situations such as causing the user to have questions such as making a sound every time the power is turned on, or causing anxiety that it is a malfunction. become. Even after the set time has elapsed since the power was turned on, when it is desired to check whether the defrosting solenoid valve 19 is open or closed for maintenance, after the power is turned on once, for example, the outlet is immediately disconnected and the outlet is reinserted. As a result, the open / close necessity flag can be restored to the original “1”, whereby the forced open / close conversion of the defrosting electromagnetic valve 19 can be executed.

1 Heat Pump Unit 2 Hot Water Storage Unit 11 Compressor 12 Condensation Heat Exchanger (Condenser)
13 Expansion valve (pressure reduction means)
14 Evaporation heat exchanger (evaporator)
15 Refrigerant circulation pipe 18 Bypass path 19 Defrosting solenoid valve (open / close control valve)
3, 3a controller (control means)
SUB1, SUB3 Defrosting solenoid valve check control (initial control)

Claims (2)

A heat pump unit in which a compressor, a condenser, a decompression unit, and an evaporator are connected in order through a refrigerant circulation pipe, and a bypass path that supplies the refrigerant discharged from the compressor by bypassing the decompression unit to the evaporator And a normally-closed open / close control valve interposed in the bypass passage, and opening / closing the open / close control valve when the defrost start condition for the evaporator is established, and introducing high-temperature refrigerant from the compressor into the evaporator A heat pump hot water supply device comprising a control means for controlling the defrosting operation,
The control means is configured to perform initial control for opening / closing conversion of the open / close control valve when the power is turned on regardless of whether the defrost start condition is satisfied or not.
A heat pump hot water supply apparatus characterized by that. It is a heat pump hot-water supply apparatus of Claim 1, Comprising:
The heat pump hot water supply apparatus, wherein the control means is configured not to perform the initial control when a predetermined set time elapses after power is turned on.

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