JP2013119954A - Heat pump hot water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump hot water heater that has high defrosting capacity and can achieve highly efficient defrosting operation using stored heat.SOLUTION: A heat pump hot water heater includes a heat pump cycle having a compressor 1, a water-refrigerant heat exchanger 2, a pressure reducer 3, and an air heat exchanger 4 connected in sequence, and a hot water circuit having the water-refrigerant heat exchanger 2, a hot water circulating means 13, an opening and closing means 24, and a bypass circuit 23 for bypassing the water-refrigerant heat exchanger 2. During transition from a normal heating operation to a defrosting operation, operation of the heat pump cycle is continued, and the opening and closing means 24 is opened and heat storage operation is performed for circulating hot water between the bypass circuit 23 and the water-refrigerant heat exchanger 2.

Description

  The present invention relates to a heat pump type hot water heater.

  Conventionally, a defrosting method of this type of heat pump type hot water heater generally employs a defrosting method in which a four-way valve is switched and a refrigerant in a refrigeration cycle flows in the reverse direction.

  That is, in the defrosting operation, the flow direction of the refrigerant is the same as that during cooling, and a high-temperature and high-pressure refrigerant is passed through the outdoor heat exchanger to melt frost adhering to the heat exchanger.

  In this defrosting method, the water-refrigerant heat exchanger becomes an evaporator during defrosting, so when the temperature of water is low during defrosting operation or when the flow rate of water drops due to problems such as dust However, there has been a basic problem that the temperature of the water further decreases, the water in the water-refrigerant heat exchanger freezes, and the water-refrigerant heat exchanger breaks down.

  As a countermeasure to this basic problem, in general, a method of heating with a heater so that the temperature of hot water does not decrease during defrosting operation is devised, or a method of responding by replacing water with antifreeze is proposed, Has been implemented. In hot water supply equipment, as a method of defrosting operation, a method of performing a defrosting operation while maintaining a heating operation circuit without switching a four-way valve has been proposed and implemented.

  FIG. 6 is a configuration diagram of a refrigeration cycle and a water circuit of a conventional hot water supply apparatus.

  As shown in the figure, a heat pump circuit in which a compressor 111, a hot water supply heat exchanger 112, an expansion valve 113A, and an evaporator 114 are connected by piping, a hot water storage tank 120, and a fluid circuit in which a fluid circulation pump 123 is connected by piping. A heat pump hot water supply apparatus having a defrosting start determining means for determining the start of defrosting, and reducing the flow rate of the fluid circulation pump 123 before or after the defrosting start determination, and generating a minimum flow rate of the fluid circulation pump 123 An invention that operates in a region close to this region is disclosed (for example, see Patent Document 1).

JP-A-2005-147609

  However, in this refrigeration cycle method, the amount of heat of the compressor used for the defrosting operation is small, and the defrosting may not end in time.

  In the case of a hot water heater used in a cold region, if the heating refrigerant in the heat pump circuit is passed through the water-refrigerant heat exchanger, the amount of heat necessary for defrosting is taken away by the water-refrigerant heat exchanger. In some cases, frost cannot be melted and remains due to poor defrosting.

  In general, in the defrosting operation using the four-way valve switching method, the method of increasing the temperature of the water circuit with the heater is also inefficient in operation during the defrosting operation, and adding the heater increases the product cost. There are many issues.

This invention solves the said conventional subject, and it aims at providing the heat-pump type hot water heater which can implement | achieve highly efficient defrosting operation with high defrosting capability using heat storage.

  In order to achieve the above object, a heat pump hot water heater of the present invention includes a heat pump cycle in which a compressor, a water-refrigerant heat exchanger, a decompressor, and an air heat exchanger are sequentially connected, and the water-refrigerant heat exchanger. A hot water circuit having a bypass circuit for bypassing the water-refrigerant heat exchanger, and a control device provided with a hot water circulation means and an opening / closing means, and at the time of transition from a normal heating operation to a defrosting operation, the heat pump cycle This operation is continued, and the opening / closing means is opened, and a heat storage operation is performed in which hot water is circulated between the bypass circuit and the water-refrigerant heat exchanger.

  Thereby, since the defrosting operation can be performed using the heat stored in the water circuit by the heat pump without mounting the four-way valve on the product, an operation with high efficiency during the defrosting operation can be performed. Moreover, since this structure utilizes the heat storage amount in order to increase the defrosting power, the defrosting operation can be completed in an earlier time than the operation of defrosting only with the input heat of the compressor.

  ADVANTAGE OF THE INVENTION According to this invention, the heat pump type hot water heater which can implement | achieve a highly efficient defrost operation using a thermal storage with high defrosting capability can be provided.

The block diagram of the heat pump type hot water heater in Embodiment 1 of this invention Block diagram of the control device for the heat pump type hot water heater Defrosting operation time chart of the heat pump type hot water heater The block diagram of the heat pump type hot water heater in Embodiment 2 of this invention The block diagram of the heat pump type hot water heater in Embodiment 3 of this invention Configuration diagram of conventional heat pump water heater

  A first invention is provided with a heat pump cycle in which a compressor, a water-refrigerant heat exchanger, a decompressor, and an air heat exchanger are sequentially connected, the water-refrigerant heat exchanger, hot water circulation means, and opening / closing means, A hot water circuit having a bypass circuit for bypassing the water-refrigerant heat exchanger, and a control device; during the transition from the normal heating operation to the defrosting operation, the operation of the heat pump cycle is continued; It is a heat pump type hot water heater that is open and performs a heat storage operation for circulating hot water between the bypass circuit and the water-refrigerant heat exchanger.

  Thereby, since the defrosting operation can be performed using the heat stored in the water circuit by the heat pump without mounting the four-way valve on the product, an operation with high efficiency during the defrosting operation can be performed. Moreover, since this structure utilizes the heat storage amount in order to increase the defrosting power, the defrosting operation can be completed in an earlier time than the operation of defrosting only with the input heat of the compressor.

  Further, since the four-way valve is not mounted, the heat loss between the discharged refrigerant and the suction refrigerant inside the four-way valve is eliminated in the operation when the normal warm water heating is performed, and the efficiency in the normal heating operation is increased. In addition, the structure is simplified and the material cost is low.

  Further, there is no generation of refrigerant sound due to the four-way valve switching defrosting, and there is no problem that the cold water circulates in the panel and the panel temperature decreases. From such an operation, the user does not notice that the user has entered the defrosting operation during the defrosting operation and does not feel uncomfortable.

In a second aspect of the present invention, after reducing the operating frequency of the compressor during the transition to the defrosting operation,
The hot water circulating means is operated with a reduced rotation speed.

  Thereby, it can be stored in the water circuit of the outdoor unit before entering the defrosting operation. In addition, the temperature of the hot water can be increased more quickly by reducing the number of revolutions of the pump, which is the hot water circulation means, and the pressure suddenly increases at the operating frequency of the normal compressor, exceeding the allowable pressure of the compressor. Therefore, the refrigerant circulation amount of the compressor is reduced, the pressure load due to the rapid increase in high pressure is reduced, and the defrosting operation can be performed by quickly storing heat in the water circuit.

  In addition, rapid pressure fluctuations and oil discharge of the compressor due to high frequency operation are reduced, and highly reliable operation is possible.

  According to a third aspect of the present invention, there is provided temperature detecting means for detecting a refrigerant temperature of the water-refrigerant heat exchanger, and the decompressor is operated in the opening direction after the temperature detected by the temperature detecting means reaches a predetermined temperature. And defrosting operation is started.

  Thus, heat can be stored in the water circuit before the defrosting operation, and the defrosting operation can be started using the heat with certainty, so that the defrosting capability is high and the defrosting can be performed in a short time. Incidentally, the maximum refrigerant condensing temperature is about 55 ° C. Since this heat storage amount can be secured at a constant level, the defrosting power during the defrosting operation can also be secured at a constant level.

  According to a fourth aspect of the present invention, the opening of the decompressor is operated in the opening direction, and the blower that blows air to the hot water circulation means and the air heat exchanger is stopped when the opening is substantially fully open.

  Thus, the stored heat and the input heat of the compressor can be reliably utilized for defrosting the air heat exchanger without radiating to the outside air.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 is a configuration diagram of a heat pump hot water heater in the first embodiment of the present invention. In the figure, an outdoor unit 20 includes a heat pump circuit including a compressor 1, a water-refrigerant heat exchanger 2, a decompressor 3, and an air heat exchanger 4, a blower 5 for blowing air to the air heat exchanger 4, and hot water. Return pipe 11, water supply tank 12, pump 13 as hot water circulation means, hot water outgoing pipe 14, bypass circuit 23, two-way valve 24 as opening / closing means, thermal valve a 15 a, thermal valve b 15 b, thermal valve c 15 c, heat A thermal valve hot water circuit comprising a valve d15d is provided. The decompressor 3 here may be an electromagnetic expansion valve.

  Terminal panels (warm floor panels) 16 and 17 are connected to the warm water return pipe 11 and warm water outlet pipe 14, and an operation remote controller 18 for the user to set the temperature of the terminal panels (floor warm panels) 16 and 17. Is installed.

  Further, the water supply tank 12 is not limited because the water-refrigerant heat exchanger 2 and the hot water circulation means may be provided without the water supply tank 12.

  Moreover, in FIG. 1, the flow of a refrigerant | coolant and the flow of warm water are shown. The refrigerant flow is indicated by arrows, and the hot water flow is indicated by block arrows.

Before the defrosting operation is received, the water circuit side receives the determination to start the defrosting operation, operates the pump 13 of the hot water circulation means at a low speed, operates the two-way valve 24 in the opening direction, and flows the water circuit outdoor. Circulate in unit 20. The heat pump side continues the heating operation without stopping the compressor 1 operation, and stores the heat obtained by the heat pump in the water-refrigerant heat exchanger 2 and the water supply tank 12.

  FIG. 2 is a block diagram of the control device for the heat pump type hot water heater in the first embodiment of the present invention. As shown in FIG. 3, when the defrost start determination is made by the defrost start determination means 57 on the outdoor unit 20 side and it is determined that the heat storage operation is before the start of defrosting, the compressor operation means 51 and the decompressor opening variable The defrosting start determination is transmitted to the means 52, the fan operating means 53, the defrosting start receiving means 60 for controlling the water circuit, the pump operating means 65, the thermal valve a15a opening / closing means 61, the thermal valve b15b opening / closing means 62, the heat The operation of each valve is controlled by the valve c15c opening / closing means 63, the heat valve d15d opening / closing means 64, and the two-way valve opening / closing means 66, and after the heat storage operation, the operation proceeds to the defrosting operation.

  Moreover, the refrigerant | coolant condensing temperature detection means 30 and the air heat exchanger temperature detection means 32 which detect the temperature of the water-refrigerant heat exchanger 2 are arrange | positioned. In this block diagram, the defrosting start signal and the reception signal are separated, but the separation of the microcomputers is not limited, and may be handled by one microcomputer.

  FIG. 3 is a time chart showing the behavior when the heat pump type hot water heater according to Embodiment 1 of the present invention is operated.

  When the defrosting transition is determined, the process proceeds from the hot water heating operation by the heat pump in step 1 to the heat storage operation in step 2. At this time, the operating frequency of the compressor 1 is lowered to a predetermined frequency, and at the same time, the throttle direction is controlled so that the opening degree of the decompressor 3 also becomes the opening degree (closed direction) corresponding to the frequency of the compressor 1. . At this timing, the two-way valve 24 is operated in the opening direction so that the water flow is circulated in the outdoor unit 20.

  At this time, the operating speed of the pump 13 is decreased after a predetermined time from the defrost transition determination. In the section of step 2, heat obtained by the heat pump is stored in the water-refrigerant heat exchanger 2, the water supply tank 12, and the outdoor unit water circuit.

  Next, when shifting from step 2 to step 3, when the refrigerant condensing temperature of the water-refrigerant heat exchanger 2 reaches a set temperature, it is determined that heat can be stored, and the defrosting operation start is started. To do.

  Next, in step 3, the opening of the decompressor 3 is controlled to be fully open or close to full open, and the blower 5 is stopped and defrosting is started. In addition, after the start of step 3, the frequency of the compressor 1 is increased after a certain time to increase the defrosting power. At this time, the pump 13 and the blower 5 are stopped. The two-way valve 24 is also operated in the closing direction.

  Next, in step 4, the defrosting operation is continued, and when the temperature of the air heat exchanger 4 becomes equal to or higher than a set temperature (about 4 ° C.), the temperature of the air heat exchanger 4 is further determined from the determination of the completion of the defrosting. In order to raise the pressure, the throttle opening degree of the decompressor 3 is controlled slightly in the closing direction (about 400 pulses).

  Next, after defrosting is determined, the process proceeds from step 4 to step 5. At this time, the compressor 1 frequency shifts to an operation frequency at which normal warm water heating is started. The decompressor 3 also shifts to the opening degree control at the start, and the blower 5 is also operated to return to the hot water heating operation. At this time, the pump 13 operates at a low rotation speed at the time of start-up, and shifts to a normal rotation speed after a certain time. After step 5, the normal heat pump warm water heating operation is resumed.

  In the first embodiment, the operating frequency of the compressor 1 is changed. However, the constant temperature compressor 1 can also perform heat storage heating and then perform a defrosting operation.

  Here, the start determination of defrosting is generally detected and controlled by the temperature and temperature change of the air heat exchanger 4, the outside air temperature, the operation time of the compressor 1, and the like.

(Embodiment 2)
FIG. 4 is a configuration diagram of the heat pump type hot water heater according to the second embodiment of the present invention, and shows the flow of refrigerant and the flow of hot water.

  In the figure, an outdoor unit 20 includes a heat pump circuit including a compressor 1, a water-refrigerant heat exchanger 2, a decompressor 3, and an air heat exchanger 4, a blower 5 for blowing air to the air heat exchanger 4, and hot water. From the return pipe 11, the water supply tank 12, the hot water circulating means 13, the hot water outgoing pipe 14, the bypass circuit 23, the two-way valve 24, the thermal valve a15a, the thermal valve b15b, the thermal valve c15c, and the thermal valve d15d And a thermally operated valve hot water circuit.

  Terminal panels (warm floor panels) 16 and 17 are connected to the warm water return pipe 11 and warm water outlet pipe 14, and an operation remote controller 18 for the user to set the temperature of the terminal panels (floor warm panels) 16 and 17. Is installed.

  In this arrangement, the heat stored in the water supply tank 12 can be supplied to the water-refrigerant heat exchanger with the shortest water circuit, which is more efficient.

(Embodiment 3)
FIG. 5 is a configuration diagram of the heat pump type hot water heater according to Embodiment 3 of the present invention, and shows the flow of refrigerant and the flow of hot water.

  As a structure on the heat pump side, the outdoor unit 20 is provided with a compressor 1, a decompressor 3, and an air heat exchanger 4, and the indoor unit 21 is provided with a hot water return pipe 11, a water-refrigerant heat exchanger 2, a water supply tank 12, a pump 13, It is set as the structure which provided the warm water going-out piping 14. FIG. The outdoor unit 20 and the indoor unit 21 are connected by a refrigerant connection pipe 22.

  Thus, the type in which the outdoor unit 20 and the indoor unit 21 are separated can be expected to have the same effect as the integrated type of the outdoor unit 20, and is included in the present invention.

  As described above, the heat pump type hot water heater according to the present invention can be applied to deployment to large-sized commercial equipment because it has high defrosting capability and high efficiency defrosting operation using heat storage.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Water-refrigerant heat exchanger 3 Pressure reducer 4 Air heat exchanger 5 Blower 11 Hot water return piping 12 Water supply tank 13 Pump (hot water circulation means)
14 Hot water outlet pipe 15a Thermal valve a
15b Thermal valve b
15c Thermal valve c
15d Thermal valve d
16 Panel a
17 Panel b
18 Operation remote control 20 Outdoor unit 21 Indoor unit 22 Refrigerant connection piping 23 Bypass circuit 24 Two-way valve (opening / closing means)

Claims (4)

A heat pump cycle in which a compressor, a water-refrigerant heat exchanger, a decompressor, and an air heat exchanger are sequentially connected; and the water-refrigerant heat exchanger, hot water circulation means, and opening / closing means are provided. A hot water circuit having a bypass circuit that bypasses the control circuit, and a control device, during the transition from the normal heating operation to the defrosting operation, the operation of the heat pump cycle is continued, and the opening / closing means is opened, and the bypass circuit A heat pump type hot water heater that performs a heat storage operation for circulating hot water between the water-refrigerant heat exchanger and the water-refrigerant heat exchanger. 2. The heat pump hot water heater according to claim 1, wherein after the operation frequency of the compressor is reduced during the transition to the defrosting operation, the operation is performed with the rotation speed of the hot water circulation means being reduced. Temperature detecting means for detecting the refrigerant temperature of the water-refrigerant heat exchanger is provided, and after the temperature detected by the temperature detecting means reaches a predetermined temperature, the decompressor is operated in the opening direction to perform a defrosting operation. The heat pump type hot water heater according to claim 1 or 2, wherein the heat pump type hot water heater is started. The heat pump hot water heater according to claim 3, wherein the opening of the decompressor is operated in the opening direction, and the blower that blows air to the hot water circulation means and the air heat exchanger is stopped when the opening is substantially fully open. Machine.

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