JP4058447B2 - Heat pump hot water heater - Google Patents

Description

  The present invention relates to a hot water heater that performs hot water supply and heating using a heat pump cycle.

  As a conventional heat pump hot water storage type hot water heater, a water circulation type heat exchanger is installed in the upper part of the tank that stores hot water at a high temperature by the heat pump cycle, and the high temperature water stored in the tank and the heater radiate and return. Japanese Patent Application Laid-Open No. 2002-349964 discloses a system in which low temperature water circulates in a heat exchanger to absorb heat from a high temperature hot water storage side, reheats the temperature, and circulates hot water to a heater through a circulation pump. (Hereinafter, referred to as Patent Document 1).

  In the conventional high-temperature hot water storage operation in the tank of this prior art, heat is exchanged with the high-pressure and high-temperature refrigerant circuit of the heat pump cycle and the circulating water drawn from the bottom of the tank by the circulation pump, the water temperature in the water circuit is raised and then returned to the top of the tank. Hot water is stored.

  Therefore, hot water is temporarily stored in the tank through a water / refrigerant heat exchanger that performs heat exchange between the water circuit and the refrigerant circuit from the heat pump cycle, and heat exchange between the high-temperature water and the water circuit circulating in the heater is separately performed. In order to carry out heating operation by absorbing heat using the installed water heat exchanger, water refrigerant heat exchange for storing hot water from the heat pump cycle to the hot water storage tank, and hot water in the tank for circulating hot water to the heater The heat exchange between water and the heating water circuit must be performed twice in total. For this reason, heat exchange efficiency falls and there exists a possibility that the energy efficiency of a system may fall.

  As another hot water supply / heating system, for example, a heating medium such as an ethylene glycol aqueous solution is circulated to warm water in a hot water storage tank or perform floor heating operation (Japanese Patent Laid-Open No. 2002-286231 (hereinafter, Patent Document 2). ).

  In the system of Patent Document 2, the hot water storage operation in the tank for hot water supply is performed by an electric heater installed in the tank, and the energy efficiency (heating capacity / power used) of the hot water is reduced to 1 or less. In addition, since the heating circuit using the heat pump cycle that is used after heating is stabilized, there is a concern that the system will be enlarged because a separate heating source is installed, and the heat pump cycle is not used for hot water supply and is configured as a heating source dedicated to heating. Therefore, it does not work in the heating operation unnecessary period such as summer, and it becomes an excessive configuration from the viewpoint of annual use. In winter, the amount of heat used for the start-up of the heating increases, so the amount of stored hot water in the tank decreases, and it may be necessary to increase the tank capacity or perform daytime hot water storage operation with a high electricity bill.

JP 2002-349964 A (summary) JP 2002-286231 A (summary)

  The present invention uses the water refrigerant heat exchanger in which the refrigerant circuit and the tank water circuit are contacted or joined to each other in order to absorb heat from the heat pump cycle in the heat pump operation in which high temperature water is stored in the tank during heating operation. It is necessary to install a water heat exchanger in the tank in order to obtain the temperature rise of the circulating water used for the heater from the hot water stored at a high temperature. Therefore, in order to circulate hot water for heating, the heat source that has absorbed heat in the heat pump cycle is temporarily stored in the tank water circuit by the water-refrigerant heat exchanger, and the high-temperature water in the tank is circulated for the heater through the water heat exchanger. Heat must be absorbed into the water to make warm water for heating. In the case of heat exchange, heat exchange efficiency occurs. Like the system, heat exchange from the high-temperature refrigerant circuit to the tank hot water, heat exchange from the hot water stored in the tank hot water to the circulating water for heating, and double heat exchange Therefore, the heat loss increases and the efficiency of the heating system is reduced. In addition, when heating is started up, hot water for heating is created by absorbing heat from the hot water in the hot water storage tank, and after starting up, the heat pump cycle heat source machine is used for tank hot water in the system that absorbs the heat source for heating from the refrigerant circuit of the heat pump cycle. Since it becomes a heat source dedicated to heating, hot water for hot water storage and startup heating is operated by a tank unit using an electric heater. Heating operation at the stable time requires a dedicated heat pump cycle heat source machine, so the system will be enlarged and the operation rate will be lowered when heating operation is not required such as in the summer of the heat pump cycle heat source machine.

In order to solve the above-described problems, a hot water supply / heating system that performs direct hot water supply and heating by a heat pump cycle heat source machine is used, and water that directly exchanges heat between the refrigerant pipe and the hot water for heating is used exclusively for heating to improve heat exchange efficiency even during heating A refrigerant heat exchanger is installed in parallel separately from the hot water water refrigerant heat exchanger, and the refrigerant pipe of the hot water water refrigerant heat exchanger, the hot water pipe, and the refrigerant pipe of the water refrigerant heat exchanger that directly exchanges heat exclusively for heating. And the heating water pipe is installed in a spiral around the hot water storage tank . (1) The refrigerant circuit for the high-temperature refrigerant at the outlet of the compressor is changed by a switching valve installed in front of the water / refrigerant heat exchanger for hot water supply and heating, and the heat exchanger for hot water supply and the heat exchange for heating in front of the decompression device Each outlet pipe of the vessel joins. Alternatively, (2) the same control is possible even if an electric expansion valve with a variable opening is installed on the outlet side of each of the hot water refrigerant heat exchanger and the heating water refrigerant heat exchanger. In addition, a check valve in the flow direction toward the pressure reducing device side is installed in front of the junction between the outlet of the water refrigerant heat exchanger for heating and the outlet of the water refrigerant heat exchanger for hot water supply. Prevents condensation.

By configuring such a heating circuit, the heating heat source can directly and efficiently absorb heat from the high-temperature refrigerant circuit of the heat pump cycle, and the water refrigerant heat exchanger can be miniaturized, and a highly efficient heating operation can be performed. . Further, the heat pump cycle heat source apparatus of the present invention has a high output, and does not use a large capacity tank unit for hot water storage, and hot water is supplied directly by a heat pump cycle refrigerant circuit and a hot water refrigerant heat exchanger of the hot water supply circuit. Heating is also performed by the refrigerant circuit and the water / refrigerant heat exchanger of the heating water circuit, so the heat exchanger, switching valve / electric expansion valve , reverse support valve , etc. can be stored in the heat pump cycle heat source machine, Contribute to the reduction of manufacturing costs, compact structure, and manufacturing costs.

A heating heat source is formed by configuring the hot water supply circuit and the heating circuit of the heat pump hot water heater / heater as described above from a refrigeration cycle, a hot water / refrigerant heat exchanger, a heating / water refrigerant heat exchanger, a heating device, a switching valve / electric expansion valve, and the like. High-efficiency heat exchange and a low-cost configuration of the heating circuit can be obtained.

  As described above, according to the present invention, efficient heating operation can be performed.

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows a hot water supply and floor heating circuit using the heat pump cycle heat source device of the present embodiment, wherein 1 is a compressor capable of controlling the number of revolutions, 2 is an evaporator that absorbs heat by heat exchange with outside air, and 3 A blower that blows air to the evaporator 2 and promotes heat exchange. 4 is a pressure reducing device that depressurizes condensed high-temperature and high-pressure refrigerant. This is a two-way valve for defrosting by flowing high-temperature refrigerant gas into the evaporator. In this embodiment, two heat pump cycles are configured independently, and two compressors, evaporators, pressure reducing devices, fans and the like are used, and the subscripts a and b distinguish the systems of equipment used in the cycle. Subscript a indicates the first system heat pump cycle, and subscript b indicates the second system heat pump cycle. The water / refrigerant heat exchanger 6 for hot water supply performs heat exchange by contacting the refrigerant circuit with the hot water / tank boiling / bath reheating water circuit. The floor heating water-refrigerant heat exchanger 8 creates hot water to be sent by a circulation pump 7 to a pipe placed over the floor heating panel 9. 21 is a three-way switching valve for switching the refrigerant circuit for hot water supply and floor heating operation.
A check valve 10 is installed between the refrigerant circuit outlet of the heating water / refrigerant heat exchanger 8 and the decompression device 4a. The refrigerant circuit of the hot water refrigerant heat exchanger is spirally installed around the auxiliary hot water storage tank 13, and the refrigerant circuit is kept at a high temperature by heat conduction from the tank to cover the periphery with a heat insulating material. There is no condensation. Reference numeral 11 is a water supply port for hot water supply and bathing, and 12 is a hot water outlet for discharging water to the bathroom and kitchen. The bypass proportional valve 19 is a valve that passes the supplied water in order to mix it with the hot water. The water proportional valve 20 includes high-temperature water composed of water from the hot-water supply water / refrigerant heat exchanger 6 and water from the hot water storage tank 13 mixed by the mixing valve 18 as needed, and low-temperature water from the water supply port 11. Is adjusted to adjust the amount of tapping water with the appropriate temperature. 17 of the hot water outlet 12 indicates a pouring solenoid valve when the hot water filling is performed on the bath 15. Reference numeral 16 denotes a circulation pump for reheating the bath 15. Reference numeral 14 denotes a tank boiling pump that circulates to the tank via the water / refrigerant heat exchanger 6 when hot water is stored in the auxiliary hot water storage tank 13.

  Here, when the hot water storage tank has a small capacity and the heat pump cycle at the start of hot water supply is in a rising transition state, the hot water in the tank is supplementarily supplied to the hot water supply circuit via the mixing valve 18.

  FIG. 2 shows an example of the hot water supply / reflective water refrigerant heat exchanger shown in the present embodiment, wherein 25 is a refrigerant pipe of a heat pump cycle of the first system, 26 is a hot water supply, water tank for raising a tank, and 27 is a second system. The refrigerant pipe 28 of the heat pump cycle is a water pipe for bathing, which is formed flat and increases the contact area of each pipe. Each first system heat pump cycle refrigerant pipe, hot water supply water pipe, second system heat pump cycle refrigerant pipe, and bath reheating water pipe are formed into a set of four in a spiral shape and installed around the auxiliary hot water storage tank.

  FIG. 3 shows a water refrigerant heat exchanger for floor heating, 29 is a refrigerant pipe for the first heat pump cycle, 30 is a hot water pipe for floor heating, 2 of the first heat pump cycle refrigerant pipe and the floor heating water pipe. The book is formed in a spiral shape and is installed around the auxiliary hot water storage tank in the same manner as the hot water refrigerant heat exchanger.

  It should be noted that various heat exchangers such as a heat exchanger in which a plurality of refrigerant thin tubes are pressed from the periphery of the water pipe can be formed into a spiral or straight pipe as a water refrigerant heat exchanger for hot water supply or heating. It is.

  In the heat pump water heater / heater configured as described above, hot water supply, bath hot water filling, bath reheating, and tank boiling operation are performed by simultaneously driving one and two heat pump cycles to reduce auxiliary hot water from the tank. Partial hot water can be directly taken from the heat absorption of the heat pump cycle, resulting in a highly efficient hot water supply operation.

  On the other hand, when floor heating is performed according to the configuration of the present invention, only one system heat pump cycle is operated as shown in FIG. 4, the refrigerant flow switching valve is switched to the floor heating side, the refrigerant flow is switched, and hot water is supplied to the floor heating panel. Operate a circulation pump to circulate. Generally, the floor heating rising load is as small as 3 kW and the stable load is as small as about 1 to 2 kW. Moreover, since the warm water for floor heating is made by exchanging heat with the high-temperature side refrigerant of the heat pump cycle, the heat exchange efficiency is high, and floor heating operation with excellent energy efficiency can be performed. The temperature adjustment of the floor heating is performed by giving the controller 22 the compressor rotation speed of the heat pump cycle according to the temperature difference from the set temperature from the remote controller 23 that has detected the panel temperature, and adjusting the heat absorption amount from the water-refrigerant heat exchanger. Control the temperature. However, when there is a request for hot water supply during the floor heating operation, first, the second system heat pump cycle not connected to the floor heating circuit is activated to perform the hot water supply operation. Further, when a hot water load exceeding the hot water supply capacity of the second system heat pump cycle is generated, the refrigerant flow path of the first system heat pump cycle is switched to the hot water supply circuit side by the switching valve, and the floor heating operation is temporarily stopped.

  In addition, when the floor heating has been operated for a while, since the warm water in the floor heating panel is sufficiently warm, the following operation control is effective. That is, when there is a request for hot water supply when the heat pump cycle of the first system is performing floor heating operation, the operation of the heat pump cycle of the second system is started and the heat pump of the first system that is already in the operating state The three-way switching valve 21 of the cycle is switched so that the entire amount of the high-temperature and high-pressure refrigerant flows through the hot water-water refrigerant heat exchanger 6.

  And if the refrigerant | coolant of a 2nd system heat pump cycle becomes high temperature enough and can supply hot water independently, a hot water discharge operation will be carried out only in the 2nd system heat pump cycle. In the heat pump cycle of the first system, the three-way switching valve 21 switches the flow path and returns to the original floor heating operation.

  In the present embodiment, since the three-way switching valve 21 is used for switching the refrigerant flow path, the hot water supply side operation by the heat pump cycle of the first system is stopped during the floor heating operation, but as shown in FIG. If a valve that can flow in two directions simultaneously is used, the capacity of the second system heat pump cycle and the first system heat pump cycle capacity excluding the heating load can be added to the hot water supply side, so floor heating and high load hot water supply Simultaneous operation is possible.

  The same control is possible even if an electric expansion valve with a variable opening is installed on the outlet side of each of the hot water refrigerant heat exchanger and the heating water refrigerant heat exchanger.

  In this embodiment, a floor heating panel is connected as a heater, but bathroom drying, bathroom heating, indoor heaters, etc. can also be connected, and multiple heater devices can be connected. It is.

  In addition, when natural refrigerant is used as the refrigerant used in the heat pump cycle, especially when carbon dioxide is used and hot water (90 ° C) is stored in a conventional hot water storage tank, the temperature difference from the ambient temperature increases and the temperature from the tank increases. Increases heat dissipation. In the present invention, when a request for hot water supply or heating operation occurs, the heat pump cycle is operated to perform high-efficiency heat exchange between the refrigerant circuit and the hot water circuit, and there is no heat leakage due to heat retention, so that power saving in the hot water supply / heating system becomes significant. .

  As described above, according to the present invention, two compressors capable of controlling the number of revolutions are used to constitute independent heat pump cycle systems, and the water refrigerant heat exchanger for heating is provided in the refrigerant circuit of the heat pump cycle of the first system. And heating water that has been heated by absorbing heat from the heat exchanger is circulated in the heating device by a circulation pump, whereby efficient heating operation can be performed. In addition, by configuring the heat pump cycle independently in two systems, the second system heat pump cycle can perform hot water supply operation even during heating operation, and simultaneously perform the hot water supply load and heating operation that can be covered by the second system heat pump cycle capability. be able to.

  Further, when a hot water supply load exceeding the hot water supply capacity of the second system heat pump cycle and a heating request are generated at the same time, the structure of the three-way switching valve of the first system heat pump cycle uses a switching valve capable of simultaneous outflow in two directions. High load hot water supply and heating can be operated simultaneously.

  As described above, according to the present invention, it is possible to provide a hot water heater that can efficiently achieve hot water supply and heating operation with a small number of components in a heat pump hot water heater.

The block diagram of the hot-water supply heater in one Example of this invention. 1 is a structural diagram of a water-refrigerant heat exchanger that can be used for hot water supply and bath renewal according to the present invention. The structural diagram of the water refrigerant heat exchanger which can be used for the heating concerning this invention. The block diagram for performing operation control of the floor heating concerning the present invention. The block diagram which used the three-way valve for the refrigerant circuit of the hot water supply and heating simultaneous operation concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Speed control compressor, 4 ... Evaporator, 6 ... Hot water refrigerant heat exchanger, 8 ... Heating water refrigerant heat exchanger, 9 ... Floor heating panel, 11 ... Water inlet, 12 ... Outlet, 13 ... Auxiliary Hot water storage tank, 15 ... bathtub, 19 ... bypass proportional valve, 20 ... water proportional valve, 21 ... refrigerant flow path switching valve, 22 ... cycle control device, 23 ... floor heating remote control, 24 ... 2-way outflow 3-way switching valve.

Claims (4)

A compressor that compresses the refrigerant; a heat exchanger for hot water supply to which the high-temperature refrigerant discharged from the compressor is supplied; a decompression device that decompresses the heat-exchanged refrigerant therein; and an evaporation that vaporizes the decompressed refrigerant A heat pump cycle in which the devices are sequentially connected,
Control means for controlling the rotational speed of the compressor to increase or decrease the amount of heat absorption from the hot water supply heat exchanger;
A heat exchanger for heating which is connected in parallel with the heat exchanger for hot water supply and performs heat exchange with a refrigerant branched from the heat pump cycle;
A hot water storage tank for storing the hot water exchanged by the heat exchanger for hot water supply ,
The refrigerant pipe and hot water pipe of the hot water heat exchanger, and the refrigerant pipe and heating water pipe of the heating heat exchanger are installed in a spiral around the hot water storage tank,
A heating circuit is formed by connecting the heating device with the heating heat exchanger and the heating device, heat is exchanged between the refrigerant and the fluid in the heating circuit, and heating is performed by the heating device. Heat pump type hot water heater that can. In claim 1, the water supplied from the water supply port by the heat absorption from the hot water supply heat exchanger is heated so that it can be directly supplied with hot water, and if necessary, hot water from the hot water storage tank via a mixing valve, And / or a heat pump type hot water heater that mixes the low-temperature water from the water supply port via the bypass proportional valve with the water to be discharged and supplies the water at an appropriate temperature to the outlet. . In claim 1 or 2,
The hot water storage tank in which the piping is installed in a spiral shape is the periphery of the piping installed in a spiral shape.
A heat pump type hot water heater with a heat insulating material. The heat pump hot water heater according to any one of claims 1 to 3, wherein the refrigerant used in the heat pump cycle is a natural refrigerant.

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