JP2008025962A - Heat pump water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem in a heat pump water heater that when it is set with a pipe length of a predetermined length or more, circulation of water is deteriorated due to a flow rate lower than expected, causing operation stop as a product. <P>SOLUTION: This water heater comprises a pipe length setting means 25 for distinctly setting a pipe length. When the pipe length setting means determines that a set pipe length is a predetermined length or more, a fluid circulating pump 23 is operated while increasing a fixed flow rate for operating the fluid circulating pump 23 in the predetermined length or less at a fixed rate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to operation control of a fluid circulation pump during long piping in a heat pump water heater.

In the prior art, the heat pump hot water supply device does not have a pipe length setting means, and even if the pipe length is installed with a predetermined length or more depending on the installation situation, the heat pump water heater operates only at a fixed flow rate less than the predetermined length. (See, for example, Patent Document 1).
JP 2005-140439 A

  However, in the conventional configuration, when the pipe length is set longer than a predetermined length, the flow rate is lower than expected, so the water circulation is worsened and the operation stops as a product. There was a problem that there was.

  The present invention solves the above-described conventional problems, and includes a pipe length setting unit in the heat pump water heater, so that even if the pipe length setting unit determines that the pipe length is equal to or longer than a predetermined length, The fixed flow rate for operating the fluid circulation pump at a certain length or less is increased at a constant rate, and the fluid circulation pump is operated to prevent the operation from being stopped as a product.

  In order to solve the conventional problems, a heat pump unit type hot water supply apparatus of the present invention includes a heat pump unit having a heat pump circuit in which a compressor, a hot water heat exchanger, an expansion valve, and an evaporator are connected by piping, and a heat pump. In a heat pump hot water supply apparatus comprising a fluid circulation pump that determines the flow rate according to an instruction from the unit and a hot water storage tank unit having a hot water storage tank for storing hot water boiled by the heat pump unit, a pipe length connecting the heat pump unit and the hot water storage tank unit If the pipe length setting means determines that the pipe length is greater than or equal to a predetermined length, a fixed flow rate for operating the fluid circulation pump at a predetermined length or less is set to a fixed flow rate. The fluid circulation pump is operated at an increased rate.

  As a result, even when the pipe length is set longer than the predetermined length, it is determined that the pipe length is longer than the predetermined length by the pipe length setting means, and the fluid circulation pump is operated below the predetermined length. The fluid circulation pump can be operated by increasing the flow rate at a certain rate, so that the product can be prevented from being stopped.

  The heat pump unit type hot water supply apparatus of the present invention has pipe length setting means, and when the pipe length setting means determines that the pipe length is equal to or longer than a predetermined length, the fluid circulation pump is operated below the predetermined length. By operating the fluid circulation pump with the fixed flow rate to be increased at a certain rate, it is possible to prevent the operation of the product from being stopped and to provide the product regardless of the installation situation .

A first invention includes a heat pump unit having a heat pump circuit in which a compressor, a hot water supply heat exchanger, an expansion valve, and an evaporator are connected by piping, a fluid circulation pump that determines a flow rate according to an instruction from the heat pump unit, and A heat pump water heater comprising a hot water storage tank unit having a hot water storage tank for storing hot water boiled by the heat pump unit. When it is determined that the set pipe length by the means is equal to or longer than the predetermined length, by performing a fixed flow rate increasing operation in which the fixed flow rate for operating the fluid circulation pump at a predetermined length or less is increased at a constant rate, Providing products without being affected by installation conditions, which can prevent the product from stopping operation, etc. Theft is possible.

  The second invention is the first invention in particular, and the fluid circulation pump is provided on the heat pump side, and by performing a fixed flow rate increasing operation, it is possible to prevent operation stop as a product, and it depends on the installation situation. The product can be provided without any problems.

  The third aspect of the invention is the first aspect of the invention, in particular, in the fixed flow rate increasing operation of the fluid circulation pump before the compressor starts, immediately after the start, or after the stop, or during the defrost control or the freeze prevention control. By performing in any one or two or more cases, it is possible to prevent the operation of the product from being stopped, and it is possible to provide the product regardless of the installation situation.

  According to a fourth invention, in the heat pump water heater of the first to third inventions, the heat pump circuit is a supercritical heat pump cycle in which the pressure of the refrigerant is equal to or higher than the critical pressure, and the refrigerant in the heat exchanger for hot water supply is critical. Since the pressure is higher than the pressure, it does not condense even if the temperature is lowered due to heat deprived by the water in the hot water supply heat exchanger. Therefore, it becomes easy to form a temperature difference between the refrigerant and water over the entire area of the heat exchanger for hot water supply, so that hot water can be obtained and the heat exchange efficiency can be increased.

  The fifth invention is the heat pump water heater of the first to fourth inventions, wherein the refrigerant to be used is carbon dioxide, and the product cost is reduced by using relatively inexpensive and stable carbon dioxide as the refrigerant. It is possible to reduce the reliability and improve the reliability. In addition, carbon dioxide has an ozone depletion coefficient of zero and a global warming coefficient of about 1/700 of the alternative refrigerant HFC-407C, which is very small.

(Embodiment 1)
FIG. 1 is a circuit configuration diagram of the heat pump water heater in the first embodiment of the present invention. First, the heat pump circuit of the heat pump hot water supply apparatus according to the present embodiment will be described.

  The heat pump circuit 10 is configured by connecting a compressor 11, a hot water supply heat exchanger 12, a main expansion valve 13A, a capillary tube 13B, and an evaporator 14 in this order by piping. A blower 15 for sending air to the evaporator 14 is installed on the leeward side of the evaporator 14. The heat pump circuit 10 includes a temperature sensor 10A for detecting the temperature of the compressor 11, a temperature sensor 10B for detecting the refrigerant temperature discharged from the compressor 11, a pressure sensor 10C for detecting the refrigerant pressure discharged from the compressor 11, and an evaporator. 14 includes a temperature sensor 10D for detecting the intake air 14 and a temperature sensor 10E for detecting the evaporator temperature of the evaporator 14. Here, the temperature sensor 10 </ b> A detects cold start, and the pressure sensor 10 </ b> C detects abnormality of the compressor 11 or the heat pump circuit 10.

  Next, a hot water storage circuit of the heat pump hot water supply apparatus according to the present embodiment will be described.

A bottom pipe 21 of the hot water storage tank 20 is connected to a water supply pipe 32 such as a water pipe via a pressure reducing valve 31. Further, the bottom piping 22 of the hot water storage tank 20 is connected to the inflow side of the water piping 12A of the hot water heat exchanger 12 via the fluid circulation pump 23. It is controlled by the setting of the pipe length setting means 25. The upper circulation pipe 24 of the hot water storage tank 20 is connected to the outflow side of the water pipe 12A. The hot water storage tank 20 according to the present embodiment is a stacked hot water storage tank, and is configured so that stirring in the tank is prevented and high temperature water is accumulated at the top and low temperature water is accumulated at the bottom.

  On the other hand, the upper hot water supply pipe 33 of the hot water storage tank 20 is connected to the mixing valve 34. Further, a water discharge pipe 35 branched from the bottom pipe 21 of the hot water storage tank 20 is connected to the mixing valve 34. The outlet circuit on the outflow side of the mixing valve 34 is connected to a faucet 36 for hot water supply such as a kitchen or a washroom. This tapping circuit is provided with a flow sensor 30A for detecting the tapping amount and a temperature sensor 30B for detecting tapping temperature.

  The hot water storage tank 20 is provided with a plurality of temperature sensors 20A, 20B, 20C for detecting the amount of hot water in the hot water storage tank 20. In addition, a temperature sensor 20 </ b> D that detects the incoming water temperature derived from the bottom pipe 22 of the hot water storage tank 20 is provided in the inflow side pipe of the water pipe 12 </ b> A. In addition, the upper circulation pipe 24 is provided with a temperature sensor 20E that detects a tapping temperature derived from the water pipe 12A.

  Hereinafter, the hot water storage operation of the heat pump water heater according to the present embodiment will be described.

  When the time reaches a predetermined time or the temperature sensors 20A, 20B, and 20C in the hot water storage tank 20 detect that the amount of hot water in the hot water storage tank 20 has become less than a predetermined amount, the heat pump circuit 10 is operated to store hot water. Start driving.

  In the heat pump circuit 10, the refrigerant compressed by the compressor 11 dissipates heat by the hot water supply heat exchanger 12, is decompressed by the main expansion valve 13 </ b> A and the capillary tube 13 </ b> B, and then is sent by the blower 15 by the evaporator 14. Heat is absorbed from the air and is sucked into the compressor 11 in a gas state.

  On the other hand, by the operation of the fluid circulation pump 23, the water in the hot water storage tank 20 is guided to the water pipe 12A through the bottom pipe 22 and the hot water heated by the water pipe 12A passes through the upper circulation pipe 24. And returned to the hot water storage tank 20.

  The capacity control in the compressor 11 and the opening degree control in the expansion valve 13 are controlled such that the refrigerant discharge refrigerant temperature detected by the temperature sensor 10B maintains a preset temperature.

  Next, when it is determined using FIG. 2 that the pipe length according to the present embodiment is equal to or longer than the predetermined length, the fixed flow rate for operating the fluid circulation pump below the predetermined length is increased at a constant rate. The operation of the fluid circulation pump will be described.

  FIG. 2 is a flowchart showing a method of increasing the fixed flow rate according to the present embodiment.

  It is determined whether the length of the pipe length set by the pipe length setting (S41) is equal to or longer than the predetermined length (S42). If it is determined that the length is less than the predetermined length, the fixed flow rate X is used (S42). When it is determined that the length is equal to or longer than the predetermined length, the fixed flow rate X × (1 + α) (S43), which is increased at a fixed rate to the fixed flow rate X, is determined as the flow rate of the fluid circulation pump (S45).

  Then, the fixed flow rate increasing operation of the fluid circulation pump is performed either before the compressor is started, immediately after the compressor is started, after the compressor is stopped, during defrosting control, or during freeze prevention control. Alternatively, by performing the operation in two or more cases, it is possible to prevent the operation of the product from being stopped, and it is possible to provide the product regardless of the installation state.

  In the present embodiment, the case where the hot water storage tank is provided has been described. However, an instantaneous water heater type heat pump hot water supply apparatus that discharges hot water heated by a hot water supply heat exchanger as it is may be used.

  In addition, the heat pump circuit 10 according to the present embodiment preferably uses carbon dioxide as a refrigerant and is operated in a state where the critical pressure is exceeded on the high pressure side.

  As described above, the present invention is suitable for a heat pump hot water supply apparatus.

The circuit block diagram of the heat pump hot-water supply apparatus in Embodiment 1 of this invention Sectional drawing which showed the increase method of the fixed flow volume in Embodiment 1 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Heat pump circuit 11 Compressor 12 Heat exchanger for hot water supply 13A Main expansion valve 14 Evaporator 20 Hot water storage tank 23 Fluid circulation pump 25 Pipe length setting means

Claims (5)

A heat pump unit having a heat pump circuit in which a compressor, a heat exchanger for hot water supply, an expansion valve, and an evaporator are connected by piping, a fluid circulation pump that determines a flow rate according to an instruction from the heat pump unit, and boiling in the heat pump unit A heat pump hot water supply apparatus comprising a hot water storage tank unit having a hot water storage tank for storing raised hot water, comprising a pipe length setting means for distinguishing a pipe length connecting the heat pump unit and the hot water storage tank unit, and the pipe length setting means When the pipe length is determined to be greater than or equal to a predetermined length, a fixed flow rate increasing operation is performed in which the fixed flow rate for operating the fluid circulation pump is increased at a constant rate below a predetermined length. Heat pump hot water supply device. The heat pump hot water supply apparatus according to claim 1, wherein the fluid circulation pump is provided on a heat pump unit side. The fixed flow rate increasing operation of the fluid circulation pump is performed before the compressor is started, immediately after the start, or after being stopped, or during any one or two or more during defrost control or freeze prevention control. The heat pump hot water supply apparatus according to claim 1, wherein the heat pump hot water supply apparatus is performed. The heat pump hot water supply apparatus according to any one of claims 1 to 3, wherein the heat pump circuit is a supercritical heat pump cycle in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure. The heat pump hot water supply apparatus according to any one of claims 1 to 4, wherein the refrigerant used is carbon dioxide.

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