JP2005106416A - Heat pump type hot water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump type hot water supply device capable of supplying hot water, even when a hot water storage tank has no water, day and night, and even during defrosting operation, by solving the problem of conventional heat pump type hot water supply devices incapable of sufficiently supplying hot water during defrosting operation, day and night. <P>SOLUTION: In this heat pump type hot water supply device, operation control is executed when supply of hot water is used at a terminal to set a mixing operation mode when the hot water storage tank has hot water, and set an instantaneous water boiling mode when otherwise. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat pump type water heater having a circuit configuration capable of smoothly supplying hot water by a heat pump refrigeration cycle and adapted to an instantaneous hot water supply method using a heat pump.

  Conventional hot water heaters have a combustion water heater that does not have a hot water tank, burns gas, etc., instantaneously boiles water with its powerful combustion heat, and supplies hot water, and a large capacity hot water tank. There was an electric water heater that used cheap electricity at nighttime to store a large amount of hot water heated by an electric heater during the night in a hot water storage tank and use the hot water stored in the hot water storage tank during the day. And recently, a heat pump type water heater that is said to be more energy efficient than an electric water heater has begun to spread.

  A heat pump water heater is equipped with a large-capacity hot water storage tank, similar to an electric water heater, and uses hot electricity at night to boil hot water in the heat pump circuit and store it in the hot water storage tank. The type used for is common. This heat pump type hot water heater uses a change in the state of the refrigerant as a heat source, so it is several times better in energy efficiency than electric heater heating, and does not combust gas, so it does not emit CO2 and is friendly to the global environment. It has been broken.

  As such a conventional heat pump type water heater, there is one disclosed in Patent Document 1 below. The heat pump water heater shown in this prior art is composed of a heat pump circuit composed of a compressor, a refrigerant-to-water heat exchanger, a pressure reducing device, and an evaporator, a large-capacity hot water storage tank, a water refrigerant heat exchanger, and a hot water storage tank. It is the structure provided with the boiling circuit comprised from the circulation pump which circulates this water to a refrigerant | coolant vs. water heat exchanger.

  This heat pump type hot water heater uses an inexpensive electric power at night and operates an energy efficient heat pump circuit to store hot water in the hot water storage tank. The heat pump is gradually warmed up to a predetermined hot water temperature, and when the temperature detector detects that the predetermined hot water temperature has been reached, the operation of the heat pump circuit is stopped. During the day, when hot water is used at the terminal used, it is mixed with use water (for example, tap water) with a mixing valve and diluted to an appropriate temperature. By increasing the temperature of the hot water stored in the hot water storage tank as much as possible, the amount of water to be diluted is increased, and the amount of hot water taken out from the hot water storage tank is decreased.

  Moreover, although the heat pump water heater described in Patent Document 1 is a type of storing hot water using electric power at night as in an electric water heater, a set hot water temperature is set by a decrease in the amount of hot water or a decrease in temperature in the hot water storage tank. When the temperature cannot be obtained, the heat pump circuit can be operated to replenish hot water in the hot water storage tank, or in some cases, a reheating operation can be performed by using a heater using an electric heater and a heat pump circuit in combination.

Japanese Patent Laid-Open No. 9-126547 (see FIG. 3)

  However, since the conventional heat pump type hot water heater is a type that stores a large amount of hot water in the hot water tank, it is not used where the efficiency of the heat pump circuit is sufficiently high, and a lot of heat is generated from the surface of the large hot water tank. The energy is wasted and the energy is wasted, which causes a decrease in energy efficiency. And since it has a large-capacity hot water storage tank, a large space is required, and the transportation and installation of the water heater are troublesome.

  In addition, conventional heat pump water heaters basically use hot water boiled in the heat pump circuit at night in hot water tanks, and use the stored hot water during the day. There was a case.

  In addition, the heat pump water heater is controlled to be defrosted when frost adheres to the evaporator during nighttime operation (when hot water is stopped), but hot water runs out during the day. At that time, when the heat pump water heater is operated and frost is attached to the evaporator, if the defrosting operation is performed, the supply to the hot water supply use side terminal may not be sufficiently performed. Moreover, even after hot water has completely disappeared from the hot water storage tank, not only hot water supply but also hot water storage operation took a long time, and it was impossible to meet the demand for hot water.

  An object of the present invention is to provide a heat pump type hot water heater capable of supplying hot water even when there is no hot water in a hot water storage tank, day or night, and even during a defrosting operation.

  In order to achieve the above object, the heat pump type water heater of the present invention is discharged by a compressor, a refrigerant-to-water heat exchanger, a decompression device, a heat pump circuit connected to an evaporator, and a condenser of those heat pump circuits. A refrigerant-to-water heat exchanger that heats the water with heated heat, a hot water storage tank that stores water warmed by the refrigerant-to-water heat exchanger, and water that has been warmed by the refrigerant-to-water heat exchanger In a heat pump type water heater provided with a direct hot water supply circuit to be supplied from the heat exchanger to the use side terminal, a hot water supply control unit for controlling the hot water supply circuit, and a heat pump control unit for controlling the operation of the heat pump circuit, during the defrosting operation This is achieved by performing control that can supply hot water directly in the hot water supply circuit regardless of whether it is day or night, even when there is no hot water in the hot water storage tank when the hot water supply is used at the use side terminal.

  ADVANTAGE OF THE INVENTION According to this invention, when a use side terminal is supplied during a defrost operation, even if there is no hot water in a hot water storage tank, the heat pump type hot water heater which can supply hot water day or night can be provided.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG.

  In FIG. 1, the heat pump type hot water heater in the embodiment of the present invention includes a hot water supply circuit 3 (not including a bathtub 19 described later) and a heat pump circuit 1, 2 for heating and supplying water by the heat pump circuits 1, 2. Heat pump control units A and B to be controlled and a hot water supply control unit C to control the hot water supply circuit 3 are housed in a single box.

  The heat pump circuits 1 and 2 include a compressor 4, a four-way valve 5, a refrigerant-to-water heat exchanger 6, a decompression device 7, and an evaporator 8. A fan 8a is arranged so as to vent the outside air to the evaporator 8.

  The four-way valve 5 is used for defrost control in which a high-temperature and high-pressure refrigerant discharged from the compressor 4 is allowed to flow through the evaporator 8 by switching the valve, and frost adhering to the evaporator 8 is melted.

  The compressor 4 is controlled from a low speed (for example, 2000 rotations / minute) to a high speed (for example, 8000 rotations / minute) by PWM control, voltage control (for example, PAM control), and rotation speed control combining these. In particular, when supplying hot water directly from the refrigerant-to-water heat exchanger 9, the heat pump control units A and B operate the compressor 4 at high speed.

  Next, water is taken from the water pipe and supplied to the terminal on the use side via the refrigerant-to-water heat exchanger 9, or the water is circulated inside as described later to bring it to a predetermined temperature (for example, 42 ° C.). The hot water supply circuit 3 to be raised will be described.

  The hot water supply circuit 3 includes a pressure reducing check valve 11, a refrigerant-to-water heat exchanger 9, a hot water storage tank 10, a circulation pump 13, and mixing that mixes hot water from the hot water storage tank 10 and hot water from the refrigerant-to-water heat exchanger 9. A valve 14, a mixing valve 15 that mixes hot water from the mixing valve 14 and water from the water supply pipe 27, and a flow rate adjustment valve 16 that adjusts the flow rate of hot water are connected by a water pipe.

  The bathtub water circuit is composed of a refrigerant-to-water heat exchanger 9, a pouring solenoid valve 17, and a circulation pump 18 for the bathtub.

  The water heater of the present embodiment heats up the high-temperature refrigerant of the heat pump circuits 1 and 2 and the water introduced from the water supply pipe 27 by the heat exchange in the refrigerant-to-water heat exchanger 9, and directly goes to the terminal used. By adopting a hot water supply system, a conventional large hot water storage tank can be dispensed with.

  Although the heat of condensation sufficient to warm the water cannot be generated until the pressure condition immediately after the start of operation is stabilized, the hot water stored in the hot water storage tank 10 and the refrigerant-to-water heat exchanger can be generated for a short time. The hot water storage tank 10 can be reduced in size while maintaining the set temperature by mixing the water from 9 and supplying hot water. When the operation of the heat pump circuits 1 and 2 is stabilized and the hot water at the set temperature is boiled up, the hot water stored in the hot water storage tank 10 is stopped and the hot water is supplied directly.

  Next, supply of water to the heat pump water heater will be described. The water supplied from the water supply pipe 27 flows into the pressure reducing check valve 11, and one end of the water is diverted to the hot water storage tank 10 through the water supply pipe 27 and the other to the refrigerant-to-water heat exchanger 9. The hot water supply to the use terminal is supplied through the mixing valve 14 and the flow rate adjusting valve 16 at a set temperature. The operation of each part will be described below.

  As described above, the mixing valve 14 supplementally mixes hot water in the hot water storage tank 10 when the temperature of the hot water coming out of the refrigerant-to-water heat exchanger 9 cannot be sufficiently increased immediately after the heat pump circuit operation is started. This is a valve for supplying hot water at a set temperature to the terminal used. The mixing valve 14 and the hot water storage tank 10 are connected by a hot water supply pipe 28.

  When the temperature of the hot water supplied from the mixing valve 14 is higher than the set temperature, the mixing valve 15 reduces the hot water temperature to the set temperature by mixing with the water supplied from the water supply pipe 27. The flow rate adjustment valve 16 is a valve that regulates the flow rate so that the amount of hot water supply does not exceed the planned total amount.

  Further, each part includes a feed water temperature sensor 20, a water heat exchanger outlet water temperature sensor 21 that detects the temperature of water from the refrigerant-to-water heat exchanger 9, and hot water in the mixed hot water storage tank 10 and water in the water heat exchanger outlet. A water temperature sensor 22 that measures the temperature, a hot water temperature sensor 23 that measures the final hot water temperature, tank temperature sensors 24, 25, and 26 that measure the amount of hot water remaining in the hot water storage tank 10, and an evaporator on the refrigeration cycle side. 8, an evaporator temperature sensor 8b for measuring the intermediate temperature 8 is arranged with a suction temperature sensor 8c for sensing the suction temperature of the compressor 4.

  And other equipment other than the hot water supply circuit 3 including the heat pump circuits 1 and 2 and the hot water storage tank 10 and the bathtub 19 are accommodated in a box which will be described later.

  Next, the operation of each unit when the terminal in use is used will be described. When hot water supply starts from the use terminal, the flow sensor 12 senses the use of the terminal, starts the compressor 4 and starts the operation of the heat pump circuits 1 and 2. At the initial stage of operation, the heat pump circuits 1 and 2 are still in a standing state, so that the hot water supply operation using the hot water storage tank 10 is performed. The water introduced from the water supply pipe 27 reaches the lower part of the hot water storage tank 10 through the pressure reducing check valve 11 and the water supply pipe 27. In the hot water storage tank 10, water is supplied from the lower part thereof, and hot water stored in the upper part of the hot water storage tank 10 is pushed out to the hot water supply pipe 28 by the water pressure.

  On the other hand, the water from the water supply pipe 27 is divided into a water circuit that flows to the refrigerant-to-water heat exchanger 9 in order to heat the water by the refrigeration cycle. The temperature is sensed by the temperature sensor 22 so that the temperature is set by the mixing valve 14 that mixes the hot water from the hot water storage tank 10 and the hot water from the refrigerant-to-water heat exchanger 9. It adjusts with the quantity of the water from the refrigerant | coolant versus water heat exchanger 9 heated from the cycle. In the initial stage of the operation, the water passing through the refrigerant-to-water refrigerant heat exchanger 9 is not sufficiently warmed, so the amount of hot water from the hot water storage tank 10 is large, and the water flowing through the refrigerant-to-water heat exchanger 9 The amount is reduced (mixed operation mode). Here, in the initial stage of operation, when the amount of water flowing through the refrigerant-to-water heat exchanger 9 is reduced, the temperature can be rapidly increased due to a small amount of water.

  In this mixing operation mode, when the temperature of the hot water at the terminal used is too high (when the temperature is higher than the set value), the mixing valve 15 is opened and the water from the water supply pipe 27 is mixed to adjust the hot water temperature.

  As the operation continues, the heat pump circuits 1 and 2 begin to stabilize gradually, the temperature of hot water supplied from the refrigerant-to-water heat exchanger 9 also becomes high, and the hot water from the hot water storage tank 10 and the refrigerant-to-water heat exchanger 9 The mixing valve 14 for mixing hot water gradually narrows down the hot water from the hot water storage tank 10, and when the hot water temperature from the refrigerant-to-water heat exchanger 9 reaches the set temperature, the hot water from the hot water storage tank 10 is completely discharged. The hot water can be supplied to the terminal only with the hot water that has been closed and heated by the refrigerant-to-water heat exchanger 9 heated by the heat pump circuits 1 and 2 (instantaneous water heating mode).

  In order to supply hot water to the terminal at the set temperature at this time, the temperature is sensed by the temperature sensor 22, hot water discharged from the refrigerant-to-water heat exchanger 9 and passed through the mixing valve 14 is mixed with the bypassed water. The set hot water is supplied to the terminal by the mixing valve 15. In particular, when the temperature of water supplied from the water supply pipe 27 is high, such as in summer, the temperature of hot water output from the refrigerant-to-water heat exchanger 9 becomes higher than the set temperature. At this time, the mixing valve 15 is adjusted so as to reach the set temperature, so that water is appropriately mixed and hot water is supplied to the terminal (water mixing mode).

  When hot water is supplied to the bathtub 19 or hot water is poured, the same operation as described above (mixing operation mode, instantaneous water heater mode, water mixing mode) is performed, and the hot water solenoid valve 17 is opened to fill the bathtub 19 with hot water.

  In the present embodiment, when hot water is supplied from the use side terminal during defrosting operation, operation of a heat pump type water heater that can supply to the terminal regardless of whether it is day or night even if there is no hot water in the hot water storage tank Control is illustrated in FIG.

  First, the circuit during the defrosting operation will be described.

  The variable-temperature compressor 4 that compresses the low-temperature and low-pressure refrigerant and discharges it as a high-temperature and high-pressure refrigerant passes through the four-way valve 5, and the discharged high-temperature and high-pressure refrigerant is converted into the evaporator 8, the decompression device 7, and refrigerant-to-water heat exchange. The defrosting operation is performed with a configuration in which the vessel 6 is connected to the refrigerant pipe. During this defrosting operation, the evaporator 8 is on the condensation side and the refrigerant-to-water heat exchanger 6 is on the heat-absorbing side, so heat exchange between the refrigerant-to-water heat exchanger 6 and the refrigerant-to-water heat exchanger 9 is performed. It becomes impossible to supply hot water during defrosting operation. However, hot water is used from the use side terminal even during the defrosting operation.

  While the defrosting operation is in the operation mode of the defrosting circuit 29, when hot water is supplied, the hot water supply circuit 30 is obtained and the following operation control is performed.

  It is detected from the water heat exchanger outlet water temperature sensor 21 whether the set temperature is satisfied. If the set temperature is satisfied, the hot water in the hot water storage tank 10 is supplied without using it. However, if the set temperature is not satisfied, the opening of the mixing valve 14 is increased so that the set temperature is reached by increasing the number of revolutions of the compressor or by mixing the hot water in the refrigerant-to-water heat exchanger 9 and the hot water in the hot water storage tank 10. As a result, the flow ratio from the hot water storage tank 10 is increased, and the temperature of the hot water passing through the mixing valve 14 is adjusted. Then, the temperature sensor 22 detects whether or not the set temperature is reached. If the set temperature is reached, the hot water is supplied as it is.

  However, since the hot water from the hot water storage tank 10 is limited, the hot water temperature is specified from the detection result of the tank temperature sensor 25 among the sensors 24, 25, 26 for detecting the temperature in the hot water storage tank 10, and the hot water temperature of the tank is Hot water supply from the tank is stopped when the temperature falls below the predetermined value.

  Even if the hot water supply from the hot water storage tank 10 is exhausted, the temperature sensor 22 detects whether or not the set temperature has been reached. However, when the set temperature is not reached, hot water at the set temperature is supplied and supplied directly through the hot water supply circuit by increasing the number of revolutions of the compressor, or by restricting the mixing valve 15 and the flow rate adjusting valve 16.

  According to the present embodiment, by performing such operation control, hot water can be supplied regardless of whether it is daytime or night even when hot water is used from the terminal during the defrosting operation.

It is a block diagram of the heat pump type water heater which shows-Example of this invention. It is a control flowchart when there is hot water supply use from a use side terminal during a defrost operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 ... Heat pump circuit, 3 ... Direct hot-water supply circuit, 4 ... Compressor, 5 ... Four-way valve, 6 ... Refrigerant to water heat exchanger, 7 ... Decompression device, 8 ... Evaporator, 9 ... Refrigerant to water heat exchanger DESCRIPTION OF SYMBOLS 10 ... Hot water storage tank, 11 ... Pressure-reduction check valve, 12 ... Flow sensor, 13, 18 ... Circulation pump, 14, 15 ... Mixing valve, 16 ... Flow control valve, 17 ... Hot water solenoid valve, 19 ... Bathtub, 20 ... Water supply temperature sensor, 21 ... Water heat exchanger outlet water temperature sensor, 22, 23 ... Temperature sensor, 24, 25, 26 ... Tank temperature sensor, 27 ... Water supply pipe, 28 ... Hot water supply pipe, 29 ... Defrost circuit, 30 ... Hot water supply circuit.

Claims (3)

  A heat pump circuit connected to a compressor, a refrigerant-to-water heat exchanger, a decompression device, and an evaporator, a refrigerant-to-water heat exchanger that heats water with heat released by a radiator of the heat pump circuit, and the refrigerant A hot water storage tank for storing water warmed by the water-to-water heat exchanger, a direct hot water supply circuit for supplying water warmed by the refrigerant-to-water heat exchanger from the refrigerant-to-water heat exchanger to the use side terminal, and its direct In a heat pump type hot water heater equipped with a hot water supply control unit for controlling a hot water supply circuit and a plurality of heat pump control units for controlling the operation of the heat pump circuit, if there is hot water use at the use side terminal during the defrosting operation, the hot water storage tank A heat pump type water heater that can control hot water supply directly in the hot water supply circuit regardless of whether it is hot or cold.   The heat pump water heater according to claim 1, wherein the defrosting operation is performed by sending a refrigerant compressed to a high temperature and a high pressure by a compressor to an evaporator by a four-way valve. The heat pump water heater according to claim 1 or 2, wherein the heat pump circuit is a two-cycle system using two compressors each.

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