JP2012247079A - Heat pump type water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump type water heater warning of malfunction of an expansion valve in defrosting operation.SOLUTION: In defrosting operation that an output from a compressor 4 installed on a refrigerant circuit 8 for melting frost attached to an air heat exchanger 7 is increased by a predetermined value to fully open the expansion valve 6, when it is determined that the temperature of hot water detected by a return pipe temperature sensor 23 or the refrigerant temperature detected by a water and heat mixing inlet temperature sensor 13 exceeds a predetermined value continuously for a time exceeding a predetermined time, a warning part 34 installed on a remote controller 33 warns in a voice of the malfunction of the expansion valve 6 and necessity to repair or exchange it to detect the malfunction regardless of the aperture of the expansion valve 6.

Description

  The present invention relates to a heat pump hot water supply apparatus that heats hot water in a hot water storage tank with a refrigerant circuit.

  Conventionally, in this type, a refrigerant circuit in which a compressor, a refrigerant water heat exchanger, an expansion valve, and an air heat exchanger are connected by piping, a hot water storage tank for storing hot water, the hot water storage tank and the refrigerant water heat exchanger And a heat pump circulation circuit that is connected in a ring with a pipe, drives a circulation pump installed in the heat pump circulation circuit, heats hot water in the hot water storage tank with a high-temperature refrigerant in a refrigerant water heat exchanger, and heats it. During boiling operation to raise the temperature to the target boiling temperature, the hot water in the heat pump circulation circuit heated by the refrigerant water heat exchanger after the elapse of a predetermined time from the start of the boiling operation does not reach the predetermined target boiling temperature. Reduce the circulating pump speed to the lower limit, close the expansion valve opening to the lower limit, increase the compressor output to the upper limit to increase the temperature of the hot water, and the temperature of the hot water rises to the target boiling temperature If not There is one that determines that it is abnormal.

JP 2002-213816 A

  However, in this conventional one, when the expansion valve is fixed at an intermediate opening, it is possible to raise the temperature of the hot water to the target boiling temperature by controlling the rotation speed of the circulation pump and the output of the compressor, There is a problem that the abnormality of the expansion valve cannot be detected if the hot water reaches the target boiling temperature.

  In order to solve the above problems, in claim 1 of the present invention, a compressor, a refrigerant water heat exchanger, an expansion valve, an air heat exchanger connected by piping, a hot water storage tank for storing hot water, A heat pump circulation circuit in which a hot water storage tank and the refrigerant water heat exchanger are annularly connected by piping, a hot water temperature sensor that detects the temperature of hot water near the refrigerant water heat exchanger, and the expansion valve is opened to open the compressor In the heat pump type hot water supply apparatus comprising a defrosting control means for controlling a defrosting operation in which the refrigerant whose pressure has been increased by passing through the air heat exchanger and flowing into the air heat exchanger to melt frost on the air heat exchanger, If the detected value at the refrigerant temperature sensor for detecting the temperature of the refrigerant discharged from the hot water temperature sensor or the compressor during defrosting of the air heat exchanger is equal to or higher than a predetermined value, the expansion valve malfunctions. Is notified.

  According to this invention, even if the expansion valve is fixed at the intermediate opening and the boiling operation can be performed, the refrigerant is decompressed by the expansion valve fixed at the intermediate opening during the defrosting operation. As the temperature of the hot water near the refrigerant water heat exchanger or the temperature of the refrigerant discharged from the compressor rises, the abnormality of the expansion valve is judged. Can be detected.

Schematic configuration diagram showing an embodiment of the present invention Control block diagram for explaining the heat-pon control unit of the invention The flowchart explaining operation | movement of the defrost operation of the same invention

Next, an embodiment of the present invention will be described with reference to the drawings.
Reference numeral 1 denotes a hot water storage tank unit that stores a hot water storage tank 2 for storing hot water, and 3 denotes a heat pump unit that can heat the hot water in the hot water storage tank 2.

  The heat pump unit 3 includes a compressor 4 that compresses the refrigerant to a high temperature and a high pressure, a refrigerant water heat exchanger 5 that heats hot and cold water by heat exchange with the high temperature and pressure refrigerant, an electric expansion valve 6 that decompresses the refrigerant, A refrigerant circuit 8 in which an air heat exchanger 7 that evaporates the refrigerant with air heat is connected in a ring shape with a pipe, and a blower fan 9 that sends ambient air to the air heat exchanger 7 is provided. Uses carbon dioxide as a refrigerant and constitutes a supercritical heat pump cycle.

  A heat pump control unit 10 is provided in the heat pump unit 3 and controls the output of the compressor 4 and the rotation speed of the blower fan 9. The heat pump control unit 10 flows in the refrigerant circuit 8 as a defrost control unit. The comparison means 11 for confirming the frosting state of the air heat exchanger 7 by comparing the refrigerant temperature to be performed with a predetermined value and determining the presence or absence of the defrosting operation, and the elapsed time of various operations during the defrosting operation are measured. Timing means 12.

  Here, the refrigerant water heat exchanger 5 employs a counter flow system in which the refrigerant and hot water in the hot water storage tank 2 that is heated water face each other. In the supercritical heat pump cycle, the refrigerant is super The water to be heated can be efficiently heated to a high temperature because it is condensed in a critical state, and the expansion is performed so that the temperature difference between the refrigerant inlet temperature flowing into the refrigerant water heat exchanger 5 and the outlet temperature flowing out becomes constant. If the temperature of the water to be heated flowing into the refrigerant water heat exchanger 5 is controlled at a low temperature of 5 to 20 ° C. by controlling the valve 6 or the compressor 4, the COP can be improved efficiently.

  Reference numeral 13 denotes a hydrothermal inlet temperature sensor as a refrigerant temperature sensor for detecting the temperature of the refrigerant discharged from the compressor 4 and flowing into the refrigerant water heat exchanger 5, and 14 is the temperature of the refrigerant radiated by the refrigerant water heat exchanger 5. A water heat exchanger outlet temperature sensor to be detected, 15 is an air heat exchanger inlet temperature sensor that detects the temperature of the refrigerant depressurized by the expansion valve 6 and flows into the air heat exchanger 7, and 16 is a refrigerant vapor evaporated by the air heat exchanger 7. An air heat outlet temperature sensor 17 that detects the temperature, and 17 is an outside air temperature sensor that is installed at the top of the air heat exchanger 7 and detects the ambient air temperature.

  Reference numeral 18 denotes a heat pump outgoing pipe that connects the lower part of the hot water storage tank 2 and the refrigerant water heat exchanger 5 with a pipe, 19 denotes a heat pump return pipe that connects the refrigerant water heat exchanger 5 and the upper part of the hot water storage tank 2 with a pipe, and 20 denotes a heat pump outgoing pipe. A circulation pump that is installed in the middle of the pipe 18 and circulates hot water in the pipe. By driving the circulation pump 20, hot water in the lower part of the hot water storage tank 2 flows into the refrigerant water heat exchanger 5 from the heat pump forward pipe 18. The heat pump circulation circuit 21 for storing hot water by forming hot water and flowing into the hot water storage tank 2 from the heat pump return pipe 19 is formed.

  22 is a forward pipe temperature sensor that is installed in the heat pump forward pipe 18 and detects the temperature of hot water flowing into the refrigerant water heat exchanger 5, and 23 is hot water that is installed in the heat pump return pipe 19 and heated by the refrigerant water heat exchanger 5. The return pipe temperature sensor 22 and the return pipe temperature sensor 23 serving as a hot water temperature sensor are used to detect the temperature, and the output of the compressor 4 and the rotation speed of the circulation pump 20 are determined based on the detected hot water temperature. It controls and raises to the set target boiling temperature.

  Reference numeral 24 is a water supply pipe for flowing city water into the hot water storage tank 2, 25 is a hot water discharge pipe for discharging hot water at the upper part of the hot water storage tank 2, and 26 is connected to a water supply bypass pipe 27 and a hot water supply pipe 25 branched from the water supply pipe 24. It is an electric mixing valve that adjusts the opening of the valve to make hot water at a set temperature, and supplies the hot water supply pipe 28 with the opening of the mixing valve 26 adjusted to a temperature set by the user.

  A plurality of hot water storage temperature sensors 29 are arranged in the vertical direction of the hot water storage tank 2. In this embodiment, five hot water storage temperature sensors 29a, 29b, 29c, 29d and 29e are provided. The amount of residual heat in the hot water storage tank 2 and the vertical temperature distribution in the hot water storage tank 2 can be confirmed by the temperature information detected by.

  30 is a relief valve for preventing a pressure increase due to volume expansion of the heated hot water communicated with the upper part of the hot water storage tank 2, 31 is a pressure reducing valve for reducing the pressure from the city water to a constant level, and 32 is provided on the water supply pipe 24 with a stopper. It is a hydrant.

  33 is a remote control installed in the kitchen, etc., and the user can set the hot water supply temperature, bath temperature, bath filling amount, etc. by operating various switches. Is provided with a voice guidance unit 34.

  A hot water supply control unit 35 incorporates a microcomputer that receives the input of each sensor installed in the hot water storage tank unit 1 and controls the drive of each actuator. The hot water supply control unit 35 is connected to the remote controller 33 wirelessly or by wire, and allows the user to set an arbitrary hot water supply set temperature and bath set temperature, and controls hot water supply operation, bath reheating operation, and the like.

Next, the operation of this embodiment will be described.
First, the boiling operation will be described. When the hot water storage temperature sensor 29 detects the temperature of the hot water stored in the hot water storage tank 2 in the midnight power time zone and confirms that the necessary amount of heat does not remain on the next day, The hot water supply control unit 35 issues a boiling start command to the heat pump control unit 10.

  Upon receiving the command, the heat pump control unit 10 starts driving the circulation pump 20 after starting the compressor 4, and the expansion valve 6 so that the refrigerant temperature detected by the hydrothermal inlet temperature sensor 13 becomes the target temperature. And the number of revolutions of the circulation pump 20 or the drive frequency of the compressor 4 is controlled so that the temperature detected by the return pipe temperature sensor 23 becomes the target boiling temperature. The low-temperature water of about 5 to 20 ° C. taken out from the connected heat pump outlet pipe 18 is heated to a target boiling temperature of about 70 to 90 ° C. by the refrigerant water heat exchanger 5, and the upper part of the hot water storage tank 2 from the heat pump return pipe 19 Return to.

  When the hot water stored in the hot water storage tank 2 is successively stacked and heated to the target boiling temperature and the necessary amount of heat is detected by the hot water temperature sensor 29, the hot water supply control unit 35 sends the hot water control unit 35 to the heat pump control unit 10. On the other hand, a boiling stop command is issued, and the heat pump control unit 10 stops the compressor 4 and also stops the circulation pump 20 and ends the boiling operation.

Next, a defrosting operation that occurs during the boiling operation will be described based on the flowchart of FIG.
In addition, the numerical value shown by FIG. 3 is an example, and in order to determine the presence or absence of a defrost operation, a numerical value is not limited. Specific numerical values for various determinations are set as appropriate based on the basic performance and usage environment of the hot water storage tank unit 1 and the heat pump unit 3.

  When the boiling operation is performed (S101), the comparison unit 11 determines whether the refrigerant temperature detected by the air heat exchange outlet temperature sensor 16 is equal to or lower than a predetermined value set as a defrosting operation start condition (S102). If it is determined that it is below the predetermined value, the output of the compressor 4 is increased by a predetermined value, the opening of the expansion valve 6 is maximized, the blower fan 9 and the circulation pump 20 are stopped, and the high-temperature refrigerant is supplied to the air heat exchanger 7. And defrosting operation for melting frost is started (S103).

  When the defrosting operation is started in S103, the comparison unit 11 determines whether the temperature detected by the return pipe temperature sensor 23 is equal to or higher than 108 ° C., which is a predetermined value (S104), and determines that the temperature is equal to or higher than 108 ° C. Next, the time measuring means 12 determines whether the state of 108 ° C. or higher continues for a predetermined time of 10 seconds or more (S105), and if it is determined that the state of 108 ° C. or higher continues for 10 seconds or longer, Assuming that the expansion valve 6 is not fully opened and the temperature of the refrigerant discharged from the compressor 4 is abnormally high, an error signal notifying the abnormality of the expansion valve 6 is transmitted to the remote controller 33, and the notification unit 34 sends the error signal to the expansion valve 6. The defrosting operation is terminated by informing the user that there is an abnormality and that repair or replacement is necessary (S106).

  If it is determined in S104 that the temperature detected by the return pipe temperature sensor 23 is less than 108 ° C. or the state in which the temperature of 108 ° C. or more is not continued for 10 seconds or more in S105, the comparison unit 11 determines that the hydrothermal inlet temperature sensor 13 It is determined whether or not the temperature of the refrigerant discharged from the compressor 4 detected in step S is equal to or higher than a predetermined value of 130 ° C. (S107). If it is judged by the time measuring means 12 whether or not the above is continued (S108), and if it is judged that the state of 130 ° C. or more continues for 5 seconds or more, there is an abnormality in the expansion valve 6 in S106 and repair or replacement is necessary. Is notified by voice and the defrosting operation is terminated.

  If it is determined in S107 that the refrigerant temperature detected by the hydrothermal inlet temperature sensor 13 is less than 130 ° C. or that the state of 130 ° C. or higher is not continued for 5 seconds or more in S108, the comparison means 11 It is determined whether the temperature detected by the temperature sensor 16 is equal to or higher than a predetermined value that is a defrosting operation end condition (S109). If it is determined that the temperature is higher than the predetermined value, the output of the compressor 4 and the expansion valve 6 are opened. The degree is returned to the state before the defrosting operation, the blower fan 9 and the circulation pump 20 are driven, and the boiling operation is started again (S110). If the temperature detected by the air heat exchanger outlet temperature sensor 16 is less than the predetermined value, the temperature detected by the return pipe temperature sensor 23 is confirmed again in S104.

  As described above, when the defrosting operation for melting frost of the air heat exchanger 7 is performed, the temperature detected by the return pipe temperature sensor 23 or the hydrothermal inlet temperature sensor 13 continues for a predetermined time or more. If the value is equal to or greater than the predetermined value, the notification unit 34 notifies that there is an abnormality in the expansion valve 6, so that it is possible to detect the abnormality regardless of the opening degree of the expansion valve 6. Since the control notifies the abnormality of the expansion valve 6, the abnormality of the expansion valve 6 can be detected more reliably and the safety is improved.

  The present invention is not limited to the above contents. For example, the abnormality of the expansion valve 6 can be notified from the temperature detected by the forward pipe temperature sensor 22, and the forward pipe temperature during the defrosting operation can be reported. If the temperature detected by the sensor 22 continues for a predetermined time or more and exceeds a predetermined value, it is determined that the expansion valve 6 is abnormal, and the notification unit 34 notifies that the expansion valve 6 is abnormal and needs to be repaired or replaced. The forward pipe temperature sensor 22 and the return pipe temperature sensor 23 are installed in a pipe in the vicinity of the refrigerant water heat exchanger 5, so that the rise in the temperature of hot water accompanying the rise in the refrigerant temperature can be reliably detected. To do.

  Further, in this embodiment, when it is determined that the expansion valve 6 is abnormal, the control is performed by voice notification from the notification unit 34 of the remote controller 33. For example, the expansion valve 6 is displayed on a screen that displays a hot water supply set temperature, a bath set temperature, and the like. It may be a control that displays an abnormality indicating that repair or replacement is necessary, or any other means that allows the user to grasp the abnormality of the expansion valve 6.

DESCRIPTION OF SYMBOLS 1 Hot water storage tank unit 2 Hot water storage tank 3 Heat pump unit 4 Compressor 5 Refrigerant water heat exchanger 6 Expansion valve 7 Air heat exchanger 8 Refrigerant circuit 11 Comparison means 12 Timekeeping means 21 Heaton circulation circuit 23 Return pipe temperature sensor 34 Notification part

Claims (1)

  A refrigerant circuit in which a compressor, a refrigerant water heat exchanger, an expansion valve, and an air heat exchanger are connected by piping, a hot water storage tank for storing hot water, and the hot water storage tank and the refrigerant water heat exchanger are connected in an annular shape by piping. A heated water circulation circuit, a hot water temperature sensor that detects the temperature of hot water near the refrigerant water heat exchanger, and the refrigerant that is boosted by the compressor by opening the expansion valve is allowed to pass through the air heat exchanger. A heat pump type hot water supply apparatus comprising a defrosting control means for controlling a defrosting operation for melting the frost formation of the air heat exchanger, wherein the defrosting control means is configured to remove the hot water temperature during the defrosting of the air heat exchanger. A heat pump type hot water supply apparatus that reports an abnormality of the expansion valve if a detection value of a refrigerant temperature sensor that detects a temperature of a refrigerant discharged from the sensor or the compressor is equal to or greater than a predetermined value.

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