JP5438401B2 - Hybrid hot water supply system and operation control method thereof - Google Patents

Description

  The present invention relates to a hybrid hot water supply system in which hot water is stored and supplied to a hot water supply load, in which an auxiliary hot water supply means including an electric heat pump hot water supply means and a combustion hot water heater is arranged in parallel.

A hybrid hot water supply system having an auxiliary hot water supply means composed of an electric heat pump hot water supply means and a combustion type hot water heater can be used depending on the situation, or both hot water supply means can be used at the same time. By using these advantages and complementing each other's disadvantages, it is possible to reduce running costs and initial costs, reduce CO ₂ emissions, and provide stable hot water supply.

  Among hybrid hot water supply systems, one hot water storage tank is provided with auxiliary hot water supply means including a heat pump hot water supply means and a combustion hot water heater arranged in parallel, and based on the hot water temperature detected by a temperature sensor in the hot water storage tank. In the case of a system configuration in which the heat pump hot water supply means is preferentially operated and the auxiliary hot water supply means is operated when the amount of hot water stored in the hot water storage tank is reduced, both hot water supply means can share a single hot water storage tank. The initial cost can be reduced, and the heat pump hot water supply means capable of high-efficiency operation is preferentially operated, so that it is a highly effective hot water supply system with high energy saving. As such a hybrid hot-water supply system, there is one disclosed in, for example, the following Patent Document 1 (see FIG. 1) or Patent Document 2 (see FIGS. 3 and 4).

Japanese Patent No. 4139826 JP 2007-170770 A

  FIG. 5 schematically shows a schematic configuration of a hybrid hot water supply system in which a single hot water storage tank 1 is configured by arranging heat pump hot water supply means 2 and auxiliary hot water supply means 3 including a combustion hot water machine in parallel.

  In the configuration shown in FIG. 5, the heat pump hot water supply means 2 heats the low-temperature water discharged from the water inlet / outlet 15 provided at the lower part of the hot water storage tank 1, and from the water inlet 11 provided at the upper part of the hot water storage tank 1. 1, similarly, the auxiliary hot water supply means 3 heats the low-temperature water discharged from the water outlet 14 provided at the lower part of the hot water storage tank 1 and stores the hot water from the water inlet 11 provided at the upper part of the hot water storage tank 1. Supply to tank 1. A circulation pump 20 is provided in a pipe line between a water inlet of the heat pump hot water supply means 2 and a water inlet / outlet 15 of the hot water storage tank 1, and a circulation pump 30 is provided in a pipe line between the water inlet of the auxiliary hot water supply means 3 and the water outlet 14 of the hot water storage tank 1. However, each is intervened.

  The hot water storage tank 1 is provided with a first temperature sensor 18 for detecting the water temperature in the middle portion in the vertical direction in the hot water storage tank 1 and a second temperature sensor 19 for detecting the water temperature in the lower part of the hot water storage tank 1. The temperature sensors 18 and 19 output the operation value with the operation value turned on when the detected value is less than or equal to the lower limit value of the set temperature range, and the operation value is turned off when the detected value is greater than or equal to the upper limit value. (Temperature Indicating Controller) function.

  The start and stop of the operation of the heat pump hot water supply means 2 and the circulation pump 20 is controlled by the operation value output from the second temperature sensor 19, and the start and stop of the operation of the auxiliary hot water supply means 3 and the circulation pump 30 is the first temperature sensor 18. It is controlled by the operation value output from.

  When high-temperature water is supplied from the hot water storage tank 1 to the hot water supply load 4, the pressure in the hot water storage tank 1 decreases, and from a water supply source 5 such as a water supply or water supply tank through an inlet / outlet 15 provided at the lower part of the hot water storage tank 1. Thus, low temperature water is supplied into the hot water storage tank 1. Accordingly, a high temperature water layer (high temperature layer) is formed above the hot water storage tank 1, a low temperature water layer (low temperature layer) is formed below the hot water storage tank 1, and high temperature water is supplied to the hot water supply load 4. Along with this, the low temperature water layer expands upward and pushes the high temperature layer upward. When the low temperature layer is formed, the detection value of the second temperature sensor 19 becomes equal to or lower than the lower limit value of the set temperature range of the second temperature sensor 19, and the heat pump hot water supply means 2 and the operation value output from the second temperature sensor 19 The operation of the circulation pump 20 is started, and the high temperature water heated by the heat pump hot water supply means 2 is supplied to the high temperature layer in the hot water storage tank 1, and the high temperature layer expands downward and pushes the low temperature layer downward. As a result, when the detected value of the second temperature sensor 19 is equal to or higher than the upper limit value of the set temperature range of the second temperature sensor 19, the operation of the heat pump hot water supply means 2 and the circulation pump 20 is stopped. When the amount of heat consumed by the hot water supply load 4 is large, the amount of high temperature water discharged to the hot water supply load 4 increases, and the amount of hot water heated by the heat pump hot water supply means 2 is supplied to the high temperature layer in the hot water storage tank 1. When the temperature is exceeded and the high temperature layer is pushed up further, the detection value of the first temperature sensor 18 becomes equal to or lower than the lower limit value of the set temperature range of the first temperature sensor 18 and is assisted by the operation value output from the first temperature sensor 18. The operation of the hot water supply means 3 and the circulation pump 30 is started, the high temperature water heated by the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 is supplied to the high temperature layer in the hot water storage tank 1, the high temperature layer expands downward, and the low temperature layer Press down. Accordingly, when the detected value of the first temperature sensor 18 is equal to or higher than the upper limit value of the set temperature range of the first temperature sensor 18, the operation of the auxiliary hot water supply means 3 and the circulation pump 30 is stopped. As a result, the heat pump hot water supply means capable of high efficiency operation with respect to the auxiliary hot water supply means 3 is preferentially operated, and the amount of hot water stored in the hot water storage tank 1 is set by the detection value of the first temperature sensor 18. It is maintained at a constant amount that falls within the temperature range.

  By the way, the energy consumption efficiency (coefficient of performance: COP) of the heat pump hot water supply means 2 has a characteristic that it becomes higher as the incoming water temperature is lower, and the temperature of the low-temperature water supplied from the inlet / outlet 15 provided in the lower part of the hot water storage tank 1 is The lower one is preferable because the COP becomes higher. In addition, when the load is low, the water temperature of the high temperature layer in the hot water storage tank 1 becomes the discharge temperature of the heat pump hot water supply means 2, so that the water temperature of the high temperature layer is kept constant to suppress fluctuations in the water temperature of the low temperature layer. It is preferable to achieve efficient operation. Therefore, generally, the operation of the heat pump hot water supply means 2 is controlled so that the temperature of the discharged water is constant. On the other hand, the auxiliary hot water supply means 3 composed of a combustion-type hot water machine is generally only controlled so that the heating capacity of the combustion-type hot water machine is constant because the energy consumption efficiency is not affected by the incoming water temperature. Is not controlled so that the water temperature is constant.

  That is, in the conventional hybrid hot water supply system, the auxiliary hot water supply means 3 is not controlled so that the water temperature is constant, and the water temperature depends on the heating capacity of the combustion water heater, the incoming water temperature, and the flow rate of the circulation pump 30. It is uniquely determined and constantly fluctuates according to changes in the incoming water temperature or the flow rate of the circulation pump 30.

  The operation of the auxiliary hot water supply means 3 starts when the detected value of the first temperature sensor 18 is equal to or lower than the lower limit value of the set temperature range of the first temperature sensor 18 and is continued until the detected value is equal to or higher than the upper limit value. 3, when the temperature of the discharged water 3 is lower than the upper limit value, the hot water supplied from the heat pump hot water supply means 2 is mixed with the hot water lower than the discharged water temperature of the heat pump hot water supply means 2 supplied from the auxiliary hot water supply means 3. As shown in FIG. 6, an intermediate temperature layer lower in temperature than the original high temperature layer is formed greatly below the high temperature layer in the hot water storage tank 1. When the intermediate temperature layer becomes large, the low temperature layer is pushed down, and the intermediate temperature layer reaches the inlet / outlet 15 provided at the lower part of the hot water storage tank 1. If the water temperature of the intermediate temperature layer is lower than the upper limit value of the set temperature range of the second temperature sensor 19, the operation of the heat pump hot water supply means 2 is continued without stopping, but the incoming water temperature of the heat pump hot water supply means 2 is intermediate. Since the temperature rises due to the influence of the temperature layer, the energy consumption efficiency is greatly lowered, and the operation efficiency of the entire hybrid hot water supply system is lowered.

  Further, since the intermediate temperature layer is formed by heating both the heat pump hot water supply means 2 and the auxiliary hot water supply means 3, the increase in the intermediate temperature layer means that the operating rate of the heat pump hot water supply means 2 relative to the auxiliary hot water supply means 3 is relative. The operation control of increasing the overall operation efficiency of the hybrid hot water supply system by preferentially operating the heat pump hot water supply means 2 is hindered by the formation of the intermediate temperature layer.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a hybrid hot water supply system that can be operated with high efficiency and high operation rate of a heat pump hot water supply means, and an operation control method thereof.

In order to achieve the above object, the present invention heats hot water storage tanks that store hot water to supply hot water loads and water supplied from the hot water storage tanks by exchanging heat with heat radiation from a condenser of a heat pump circuit. An electric heat pump hot water supply means for supplying to the hot water storage tank, an auxiliary hot water supply means for heating water supplied from the hot water storage tank and supplying the hot water storage tank to the hot water storage tank, and the hot water storage tank A first temperature sensor that detects a water temperature at a high temperature position of two predetermined points that have different water temperatures when a water temperature distribution occurs in the water temperature, and a water temperature at a low temperature position or the low temperature position of the two predetermined points. A hot water supply system or an operation control method thereof, wherein the auxiliary hot water supply means includes at least the above-mentioned hot water supply system. Operation start / stop control is performed based on the temperature detected by one temperature sensor, and the heat pump hot water supply means is controlled to start / stop based on at least the temperature detected by the second temperature sensor, and the heat pump hot water supply means and the auxiliary When each operation is started, the hot water supply means is controlled to discharge water temperature so that each water discharge temperature becomes a set water discharge temperature set separately or in common.
The outlet water temperature control of the auxiliary hot water supply means determines the circulation flow rate between the auxiliary hot water supply means and the hot water storage tank in accordance with the set temperature of the outlet water, the detected value of the incoming water temperature of the auxiliary hot water supply means, and the heating capacity of the auxiliary hot water supply means. When the primary control set to a fixed primary circulation flow rate and the outlet water temperature of the auxiliary hot water supply device fluctuate beyond the preset outlet water temperature by a predetermined error range or more, the primary control takes precedence over the primary control. And a secondary hot water control system that feedback-controls the circulation flow rate in a direction that suppresses the fluctuation .

  In the hybrid hot water supply system having the above characteristics, both the heat pump hot water supply means and the auxiliary hot water supply means are configured to heat the water supplied from the hot water storage tank and supply it to the hot water storage tank. Are arranged in parallel.

  It should be noted that when the water temperature distribution is generated in the hot water storage tank, the predetermined two points that have different water temperatures are, for example, when the hot water storage tank is a single tank type, and when the water temperature distribution is generated in the hot water storage tank, As the temperature becomes higher, there are two different points in the vertical direction. For example, one is the installation position of the first temperature sensor 16 shown in FIG. 1 or FIG. 4 and the other is the installation position of the water outlet 14 or the second temperature sensor 17. Respectively.

  Furthermore, in the hybrid hot water supply system or the operation control method thereof according to the above feature, the heat pump hot water supply means starts operation when the temperature detected by the second temperature sensor is equal to or lower than a predetermined first temperature, and the second temperature sensor When the detected temperature becomes equal to or higher than a predetermined second temperature higher than the first temperature, the operation is controlled to stop, and the auxiliary hot water supply means detects the temperature detected by the first temperature sensor below a predetermined third temperature. Then, the operation is started, and when the detected temperature of the first temperature sensor becomes equal to or higher than a predetermined fourth temperature higher than the third temperature, the operation is controlled to stop, and the heat pump hot water supply means and the auxiliary hot water supply means are When each operation starts, each water discharge temperature becomes a water discharge set temperature that is set separately or in common above the higher one of the second temperature and the fourth temperature. It is preferably water outlet temperature control.

Furthermore, in the hybrid hot water supply system or the operation control method thereof according to the above feature, the frequency of AC power supplied to a circulation pump interposed in a pipe line between the auxiliary hot water supply means and the hot water storage tank is changed to control the circulation flow rate. It is preferable to carry out by inverter control .

  According to the hybrid hot water supply system or the operation control method thereof having the above characteristics, in the hybrid hot water supply system having the configuration in which the auxiliary hot water supply means including the electric heat pump hot water supply means and the combustion hot water heater is arranged in parallel to the hot water storage tank. Even for the auxiliary hot water supply means with low consumption efficiency, the temperature of the outlet water is controlled in the same way as the heat pump hot water supply means, so the intermediate temperature layer formed in the hot water storage tank is greatly reduced compared to the case where the auxiliary hot water supply means is not controlled for the outlet water temperature. Since it can reduce, it can suppress that the energy consumption efficiency and operating rate of a heat pump hot-water supply means fall by an intermediate temperature layer, and can provide the hybrid hot-water supply system which can be drive | operated with high efficiency, and its operation control method.

The system block diagram which shows typically the schematic structure in one Embodiment of the hybrid hot-water supply system which concerns on this invention Explanatory drawing which shows typically the water temperature distribution in the hot water storage tank in the hybrid hot-water supply system shown in FIG. System configuration diagram schematically showing schematic configuration in another embodiment of hybrid hot water supply system according to the present invention A schematic system configuration diagram of a schematic configuration in another embodiment of a hybrid hot water supply system according to the present invention System configuration diagram schematically showing an example of a schematic configuration of a conventional hybrid hot water supply system Explanatory drawing which shows typically the water temperature distribution in the hot water storage tank in the conventional hybrid hot-water supply system shown in FIG.

  DESCRIPTION OF EMBODIMENTS Embodiments of a hybrid hot water supply system according to the present invention (hereinafter referred to as “the present invention system” as appropriate) and an operation control method thereof (hereinafter referred to as “the present invention method” as appropriate) will be described with reference to the drawings. To do. In the present embodiment, the same components and the same parts as those of the hybrid hot water supply system shown in FIG. 5 will be described with the same reference numerals for easy understanding of the present invention.

  FIG. 1 is a system configuration diagram schematically showing a schematic configuration in an embodiment of the system of the present invention. In addition, the double line in a figure has shown the piping (pipe line) of the water channel, the solid line has shown the electric power line, and the dotted line and the broken line have each shown the signal line for control. As shown in FIG. 1, the system of the present invention includes a hot water storage tank 1, an electric heat pump hot water supply means 2, an auxiliary hot water supply means 3 composed of a combustion hot water machine, and a control device 6, and the heat pump hot water supply means 2 and the auxiliary hot water supply means 3. Is arranged in parallel to the hot water storage tank 1.

  In this embodiment, the hot water storage tank 1 is assumed to be of a single tank type, and the wall of the hot water storage tank 1 has a water inlet into which water flows into the hot water storage tank 1 and water flows out of the hot water storage tank 1. There are water outlets to be used. Specifically, the water inlet 11 and the water outlet 12 are provided at the upper part, the water inlet 13 is provided at the center in the vertical direction, and the water outlet 14 and the water inlet 15 are provided at the lower part, respectively.

  Further, the hot water storage tank 1 includes a first temperature sensor 16 that detects a water temperature at an intermediate portion in the vertical direction in the hot water storage tank 1 and a second temperature sensor 17 that detects a water temperature in the lower part of the hot water storage tank 1. It is provided in a pipeline 23 connected to the water outlet 14. In the present embodiment, the second temperature sensor 17 is not installed so as to directly detect the water temperature in the lower part of the hot water storage tank 1, and is a pipe near the water outlet 14 that is substantially equal to the water temperature in the lower part of the hot water storage tank 1. The water temperature in the path 21 is alternatively detected. That is, the hot water storage tank 1 according to the present embodiment does not include the heat pump hot water supply means 2 and has conventionally performed start / stop control of the operation of the combustion hot water heater (auxiliary hot water supply means 3) only by the temperature detected by the first temperature sensor 16. The hot water storage tanks used in the hot water supply system can be used. Therefore, the system of the present invention can be configured by adding the heat pump hot water supply means 2 to the conventional hot water supply system, and it takes time and effort to bother to remodel the hot water storage tank 1 in order to install the second temperature sensor 17. Save. Similarly, the hot water storage tank 1 of the present embodiment is not provided with the auxiliary hot water supply means 3, and the conventional heat pump hot water supply in which the operation of the heat pump hot water supply means 2 is controlled only by the temperature detected by the first temperature sensor 16. The hot water tank used in the system can also be used. In addition, when the through-hole for installing the 2nd temperature sensor 17 is provided in the wall part lower part of the hot water storage tank 1, you may attach the 2nd temperature sensor 17 to the wall part of the hot water storage tank 1 directly.

  Water has a property of moving upward as the temperature increases, so-called convection. The hot water storage tank 1 is supplied with low-temperature water from a water inlet 15 provided in the lower part, and is supplied with high-temperature water from a water inlet 11 provided in the upper part. The water temperature distribution which becomes high temperature will be shown. The first temperature sensor 16 is installed at a higher temperature position in the water temperature distribution of the hot water storage tank 1 than the second temperature sensor 17.

  In the present embodiment, the first and second temperature sensors 16 and 17 do not have the function of the temperature indicating controller provided in the first and second temperature sensors 18 and 19 used in the hybrid hot water supply system shown in FIG. The detected temperature is output as an analog value of voltage or current to an analog input port of the arithmetic processing unit 61 provided in the control device 6.

  The system configuration of the system of the present invention will be specifically described below with reference to FIG.

The heat pump hot water supply means 2 is constituted by a CO ₂ heat pump adopting, for example, CO ₂ as a refrigerant of the heat pump circuit, and heats the low-temperature water that has entered from the water inlet 21 by heat exchange with heat radiation from the condenser of the heat pump circuit, The water is supplied from the water outlet 22 to the water inlet 11 of the hot water storage tank 1 through the pipeline 24. Further, the water outlet 14 of the hot water storage tank 1 and the water inlet 21 of the heat pump hot water supply means 2 are connected by a pipe 23, and an electric circulation pump 20 is interposed in the pipe 23. Thereby, a circulation path is formed between the heat pump hot water supply means 2 and the hot water storage tank 1. The circulation pump 20 may be provided in the pipe line 24, or may be provided inside the heat pump hot water supply means 2 and configured as a part of the heat pump hot water supply means 2. The compressor of the heat pump circuit is composed of, for example, a three-phase induction motor, and operates using commercial power (three-phase 200 V) as a power source.

  In the present embodiment, the heat pump hot water supply means 2 is configured to automatically control the outlet water temperature so that the set outlet water temperature is reached without depending on the control from the outside. In addition, since the discharge water temperature control of the heat pump hot-water supply means 2 is performed by the flow rate control similar to the discharge water temperature control of the auxiliary hot water supply means 3 mentioned later, detailed description is omitted.

  The auxiliary hot water supply means 3 is comprised by combustion type hot water machines, such as a gas tank vacuum type hot water machine, for example. The gas-fired vacuum water heater is provided with a furnace that heats the heat transfer water with the flame of the gas burner at the bottom of the can body, and a U-shaped heat transfer tube in the decompressed air at the top of the can body. The heat transfer water enclosed in the lower part of the gas is heated by a flame of a gas burner, and the water flowing in the heat transfer pipe is heated by heating the heat transfer pipe in the reduced-pressure steam on the upper part. The auxiliary hot water supply means 3 is composed of a combustion type hot water heater to supplement the disadvantages of the electric heat pump hot water supply means 2, and is not necessarily limited to a gas-fired vacuum hot water heater. In addition to the gas-fired water heater, which is a gas, an oil-fired water heater using petroleum as a fuel may be used, or a combustion-type water heater using other fuel or energy may be used.

  The auxiliary hot water supply means 3 introduces and heats the low-temperature water that has entered from the water inlet 31 into the heat transfer pipe, and supplies the low temperature water to the water inlet 11 of the hot water storage tank 1 through the pipes 34 and 24. The pipe line 34 connects a branch point provided in the middle of the pipe line 24 and the water outlet 32 of the auxiliary hot water supply means 3. Further, a branch point provided on the upstream side of the circulation pump 20 of the pipe line 23 and a water inlet 31 of the auxiliary hot water supply means 3 are connected by a pipe line 33, and an electric circulation pump 30 is interposed in the pipe line 33. It is disguised. Thereby, a circulation path is formed between the auxiliary hot water supply means 3 and the hot water storage tank 1. The circulation pump 30 may be provided inside the auxiliary hot water supply means 3 and may be configured as a part of the auxiliary hot water supply means 3. The circulation pump 30 may be provided on the pipe line 34 side.

  A hot water supply load 4 is connected to the water outlet 12 and the water inlet 13 of the hot water storage tank 1 via pipe lines 41 and 42. In addition, the hot water supply load 4 is comprised with a currant, a shower, a bathtub, etc., for example. When the hot water supply load 4 is a circulation load, a circulation pump 40 is interposed in the middle of the pipeline 41 (or pipeline 42). Further, a water supply source 5 is connected to the water inlet 15 of the hot water storage tank 1 through a pipe 51. The water supply source 5 is constituted by a water supply tank or a water supply tank that stores the water supply of the water supply.

  The pipes 23, 24, 33, 34, 41, 42, 51 include an on-off valve (two-way valve), a check valve, a pressure reducing valve, a constant flow valve, a safety valve, an automatic air vent valve, etc. It is assumed that necessary items are interposed as appropriate, and the illustration is omitted.

  Next, the operation control method (the present invention method) of the present system shown in FIG. 1 will be described.

  In the conventional hybrid hot water supply system shown in FIG. 5, each start / stop control of the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 is output from a first temperature sensor 18 and a second temperature sensor 19 each having a function of a temperature indicating controller. However, in this embodiment, a separate control device 6 is provided for performing on / off control of the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 and for controlling the outlet water temperature of the auxiliary hot water supply means 3.

  The control device 6 includes a calculation processing unit 61 having a dedicated microcomputer for performing calculation processing of each start / stop control of the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 and the outlet water temperature control of the auxiliary hot water supply means 3, and auxiliary hot water supply means. The inverter circuit unit 62 is configured to change the frequency of the AC power supplied to the three circulation pumps 30.

  Arithmetic processing section 61 is similar to the temperature indicating controller of first temperature sensor 18 and second temperature sensor 19 in the conventional hybrid hot water supply system shown in FIG. 5 as on / off control of heat pump hot water supply means 2 and auxiliary hot water supply means 3. In other words, when the signal values indicating the detected temperatures input from the first and second temperature sensors 16 and 17 are equal to or lower than the lower limit values of the set temperature ranges, the operation value is turned on. When the value exceeds the upper limit, the operation value is turned off and output. Hereinafter, for convenience, the lower limit value of the temperature range set by the second temperature sensor 17 is referred to as a first temperature T1, the upper limit value is referred to as a second temperature T2, and the lower limit of the temperature range set by the first temperature sensor 16 is referred to. The value is referred to as a third temperature T3, and the upper limit value is referred to as a fourth temperature T4. In the following description, as an example, it is assumed that the first temperature T1, the second temperature T2, the third temperature T3, and the fourth temperature T4 are 35 ° C., 50 ° C., 55 ° C., and 60 ° C., respectively, in the order of description.

  The inverter circuit unit 62 generates AC output power obtained by changing the frequency of commercial AC power (for example, three-phase 200 V, 50 Hz / 60 Hz) input to the primary side based on the operation value output from the arithmetic processing unit 61. Output from the secondary side to supply power to the circulation pump 30. In FIG. 1, the power supply from the inverter circuit unit 62 to the circulation pump 30 is indicated by a solid line. The discharge flow rate of the circulation pump 30 (that is, the flow rate of water flowing through the heat transfer pipe of the auxiliary hot water supply means 3) changes according to the frequency of the AC output power, and the outlet water temperature of the auxiliary hot water supply means 3 according to the principle described later. Is controlled.

  A third temperature sensor 35 for detecting the incoming water temperature of the auxiliary hot water supply means 3 is provided in the vicinity of the inlet 31 on the downstream side of the circulation pump 30 of the pipe 33 connected to the water inlet 31 of the auxiliary hot water supply means 3. In the vicinity of the water outlet 32 of the pipe 34 connected to the water outlet 32 of the means 3, a fourth temperature sensor 36 for detecting the water temperature of the auxiliary hot water supply means 3 is provided. Similarly to the first and second temperature sensors 16 and 17 that detect the water temperature of the hot water storage tank 1, the third and fourth temperature sensors 35 and 36 are not added with the function of the temperature indicating controller, and the detected temperature Is output to the analog input port of the arithmetic processing unit 61 as an analog value of voltage or current. In FIG. 1, four signal lines inputted from the temperature sensors 16, 17, 35, and 36 to the arithmetic processing unit 61 are indicated by dotted lines, and the heat pump hot water supply unit 2, the auxiliary hot water supply unit 3, and the circulation from the arithmetic processing unit 61. The control signal line output to the pump 20 is indicated by a broken line. Hereinafter, each detected temperature of the temperature sensors 16, 17, 35, and 36 is referred to as “detected temperature” including a signal value converted into an analog value of voltage or current.

  First, start / stop control of each operation of the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 in the method of the present invention will be described.

  A predetermined amount of hot water in the hot water storage tank 1 is stored, and hot water is used in the hot water supply load 4 while the operation of the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 is stopped. When hot water is supplied to the hot water tank, the pressure in the hot water storage tank 1 decreases, and low temperature water is supplied into the hot water storage tank 1 from the water supply source 5 through the inlet / outlet 15 provided in the lower part of the hot water storage tank 1. . Accordingly, since the water temperature in the hot water storage tank 1 is lowered from the lower side of the hot water storage tank 1, the temperature detected by the second temperature sensor 17 is first decreased to be equal to or lower than the first temperature T1 (35 ° C.). The arithmetic processing unit 61 of the control device 6 that has received the signal value indicating the detected temperature from the temperature sensor 17 determines that the detected temperature of the second temperature sensor 17 is equal to or lower than the first temperature T1 (35 ° C.). Then, a control signal (ON state) is output to the heat pump hot water supply means 2 and the circulation pump 20 to start each operation. When the heat pump hot water supply means 2 starts operation, the temperature control is performed by a control means (not shown) built in so that the water temperature becomes a predetermined water temperature (for example, 60 ° C. to 65 ° C.) equal to or higher than the fourth temperature T4. The hot water controlled to the outlet water temperature is supplied to the hot water storage tank 1 from the water inlet 11 at the upper part of the hot water storage tank 1. Here, when the amount of hot water used by the hot water supply load 4 is small and only the heat pump hot water supply means 2 can supply hot water, the amount of hot water stored in the hot water storage tank 1 (high temperature layer) is directed downward from above. The arithmetic processing unit 61 of the control device 6 that receives the input of the signal value indicating the detected temperature from the second temperature sensor 17 increases, and the detected temperature of the second temperature sensor 17 becomes equal to or higher than the second temperature T2 (50 ° C.). Then, it is determined that the temperature detected by the second temperature sensor 17 is equal to or higher than the second temperature T2 (50 ° C.), and a control signal (off state) is output to the heat pump hot water supply means 2 and the circulation pump 20, and each operation is performed. Stop.

  On the other hand, when the amount of hot water used by the hot water supply load 4 is large and the heat pump hot water supply means 2 alone is not enough to supply hot water, the amount of hot water stored in the hot water tank 1 (high temperature layer) further decreases, and the hot water storage tank The temperature of the low-temperature water supplied from the lower side of 1 (the low-temperature layer) increases upward, and the temperature detected by the first temperature sensor 16 decreases to become the third temperature T3 (55 ° C.) or less, and the first The arithmetic processing unit 61 of the control device 6 that has received the signal value indicating the detected temperature from the temperature sensor 16 determines that the detected temperature of the first temperature sensor 16 is equal to or lower than the third temperature T3 (55 ° C.). In addition, a control signal (ON state) is output to the auxiliary hot water supply means 3 to start operation, and the inverter circuit unit 62 is activated to instruct power supply to the circulation pump 30 and to operate the circulation pump 30. Let it begin. From the start of operation of the auxiliary hot water supply means 3 and the circulation pump 30, the control device 6 causes the auxiliary hot water supply means 3 to have a predetermined water temperature (for example, 60 ° C. to 65 ° C.) equal to or higher than the fourth temperature T4. The auxiliary hot water supply means 3 supplies the hot water controlled to the water temperature to the hot water storage tank 1 from the water inlet 11 at the upper part of the hot water storage tank 1. Note that the outlet temperature control for the auxiliary hot water supply means 3 is actually performed for the circulation pump 30 as described later. Here, when the temperature control of the auxiliary hot water supply means 3 is not performed, the temperature of the auxiliary hot water supply means 3 may drop to around 40 ° C., and hot water around 40 ° C. is mixed with a high temperature layer of about 60 ° C. Therefore, as described in the section “Problems to be Solved by the Invention”, an intermediate temperature layer is formed in the hot water storage tank 1 and the energy consumption efficiency of the heat pump hot water supply means 2 may be reduced. However, in this embodiment, since the outlet water temperature is controlled for the auxiliary hot water supply means 3, such an intermediate temperature layer is not formed, and the high energy consumption efficiency of the heat pump hot water supply means 2 can be maintained.

  If both the hot water supply means 2 and the auxiliary hot water supply means 3 are in operation, and the total amount of hot water supplied by both hot water supply means exceeds the amount of hot water used by the hot water supply load 4, the hot water in the hot water storage tank 1 is heated. The amount of hot water storage (high temperature layer) increases from above to below. First, the detected temperature of the first temperature sensor 16 becomes equal to or higher than the fourth temperature T4 (60 ° C.), and a signal indicating the detected temperature from the first temperature sensor 16 The arithmetic processing unit 61 of the control device 6 that has received the input of the value determines that the temperature detected by the first temperature sensor 16 is equal to or higher than the fourth temperature T4 (60 ° C.), and sends a control signal to the auxiliary hot water supply means 3. (OFF state) is output, the operation is stopped, the inverter circuit unit 62 is deactivated, the power supply to the circulation pump 30 is stopped, and the operation of the circulation pump 30 is stopped. Further, when the amount of hot water stored in the hot water storage tank 1 (high temperature layer) increases downward, the temperature detected by the second temperature sensor 17 becomes equal to or higher than the second temperature T2 (50 ° C.). Receiving the input of the signal value indicating the detected temperature, the arithmetic processing unit 61 of the control device 6 determines that the detected temperature of the second temperature sensor 17 is equal to or higher than the second temperature T2 (50 ° C.), and heat pump hot water supply means 2 and the circulation pump 20, a control signal (off state) is output to stop each operation.

  As described above, when the start / stop control of each operation of the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 is arranged, the hot water supply by the heat pump hot water supply means 2 has a temperature detected by the second temperature sensor 17 equal to or lower than the first temperature T1 (35 ° C.). The hot water supply by the auxiliary hot water supply means 3 starts when the temperature detected by the first temperature sensor 16 is equal to or lower than the third temperature T3 (55 ° C.) and the fourth temperature is reached. Stop at T4 (60 ° C) or higher. Here, the set values of the first temperature T1 (35 ° C.) and the second temperature T2 (50 ° C.) of the second temperature sensor 17 are set in experimental data or the like so that the auxiliary hot water supply means 3 does not enter the operating state alone. Each specific value in the parentheses is an example. Therefore, the first temperature T1 may be set to be equal to or higher than the third temperature T3, and the second temperature T2 may be set to be higher than or equal to the fourth temperature T4. In addition, the target value (predetermined value above the higher one of the second temperature T2 and the fourth temperature T4) of the water temperature control of the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 is set to the same value. In addition, there may be a difference of about 1 to 5 ° C. In addition, if the second temperature T2 is set higher than the fourth temperature T4 (60 ° C.), the target values for the water discharge temperature control of the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 are the second values, respectively. Temperature T2 or higher is set.

  Next, the water temperature control for the auxiliary hot water supply means 3 in the method of the present invention will be described. The outlet temperature control for the auxiliary hot water supply means 3 is executed by controlling the flow rate of water circulating between the auxiliary hot water supply means 3 and the hot water storage tank 1.

  Assuming that the auxiliary hot water supply means 3 is a gas-fired vacuum water heater, the control of the water heater itself is controlled by the temperature of the internal can water. For example, when the temperature of the can water becomes 83 ° C. or lower, combustion starts, and when the temperature becomes 90 ° C. or higher, the can water temperature is maintained within a predetermined control temperature range. The temperature of the can water decreases due to heat exchange with water flowing in the heat transfer tube by the operation of the circulation pump 30, and increases due to combustion. Therefore, the rated heating capacity of the auxiliary hot water supply means 3 is determined by the difference between the flow rate of water flowing through the heat transfer pipe (discharge flow rate of the circulation pump 30) and the incoming and outgoing water temperatures of the auxiliary hot water supply means 3 (heat transfer pipe). The Therefore, by adjusting the discharge flow rate of the circulation pump 30 so that the predetermined outlet water temperature is obtained based on the rated heating capacity and the incoming water temperature, the outlet water temperature can be controlled to be constant.

  Therefore, in this embodiment, the temperature control of the auxiliary hot water supply means 3 is performed by rated operation of the auxiliary hot water supply means 3 and the temperature detected by the third temperature sensor 35 installed near the water inlet 31 of the auxiliary hot water supply means 3 (incoming water temperature). The feedforward control (corresponding to the primary control) for adjusting the discharge flow rate of the circulation pump 30 based on the above is performed. Specifically, the discharge flow rate of the circulation pump 30 is adjusted by changing the frequency of the AC power supplied from the inverter circuit unit 62 to the circulation pump 30.

  The incoming water temperature and the outgoing water temperature of the auxiliary hot water supply means 3 are Ti (° C.) and To (° C.), respectively, the rated heating capacity (work rate) is A (kW), and the discharge flow rate of the circulation pump 30 is B (L / h). Then, each relationship is given by the following formula 1. In addition, 860 (kcal / kWh) in Formula 1 is a conversion coefficient between the work rate and the heat quantity per unit time. For example, when the rated heating capacity A of the auxiliary hot water supply means 3 is 110 kW and the incoming water temperature Ti is 15 ° C., when the discharge flow rate B is adjusted to 2217 (L / h), the outlet water temperature To becomes 60 ° C.

(Equation 1)
B = A × 860 / (To-Ti)

  When performing the control for starting the operation of the auxiliary hot water supply means 3, the arithmetic processing unit 61 outputs a control signal for starting operation to the auxiliary hot water supply means 3, and uses the detected temperature of the third temperature sensor 35 to The output frequency corresponding to the discharge flow rate of the circulation pump 30 calculated by the relational expression 1 is designated to the inverter circuit unit 62. For example, a plurality of discrete values are set in advance as control values for the output frequency, the correspondence between the detected temperature of the third temperature sensor 35 and the discrete value for the output frequency is tabulated, and the storage area in the arithmetic processing unit 61 Store it in. The arithmetic processing unit 61 uses the table to determine the output frequency from the input temperature detected by the third temperature sensor 35 and designates it to the inverter circuit unit 62. The inverter circuit unit 62 supplies the circulation pump 30 with AC output power having an output frequency specified by the arithmetic processing unit 61, so that the circulation pump 30 starts operation at the discharge flow rate calculated by the arithmetic processing unit 61.

  By the way, there is a possibility that the heating capacity of a combustion type hot water machine such as a gas-fired vacuum type hot water machine may change from the value set in the relational expression of the above equation 1 due to adjustment of the fuel amount, aging deterioration, or the like. Then, in the feedforward control, it is conceivable that the temperature of the outlet water of the auxiliary hot water supply means 3 deviates from the desired water temperature. Therefore, in the present embodiment, in order to perform long-term stable control in the outlet water temperature control of the auxiliary hot water supply means 3, in addition to the feed forward control (primary control) described above, feedback control (2 described below) Equivalent to the next control).

  Specifically, the feed water temperature of the auxiliary hot water supply means 3 is detected using the third temperature sensor 35 for feedforward control, and the output of the auxiliary hot water supply means 3 is used for feedback control using the fourth temperature sensor 36. The water temperature is detected, and the temperature detected by the fourth temperature sensor 36 is input to the arithmetic processing unit 61. The arithmetic processing unit 61 has a lower limit value and an upper limit value (for example, 59 ° C. and 61 ° C.) of the error range between the input detected temperature (outflow temperature) of the fourth temperature sensor 36 and the target value (for example, 60 ° C.) of the discharged water temperature. When the temperature detected by the temperature sensor 36 is lower than the lower limit value (59 ° C.), the arithmetic processing unit 61 performs an operation of lowering the discrete value of the output frequency currently specified by one step. Thereby, since the discharge flow rate of the circulation pump 30 falls by one step, the temperature of the outlet water of the auxiliary hot water supply means 3 rises. The operation of lowering the discrete value of the output frequency by one step is continued until the outlet water temperature of the auxiliary hot water supply means 3 becomes equal to or higher than the lower limit value (59 ° C.) of the target range. On the other hand, when the temperature detected by the fourth temperature sensor 36 is higher than the upper limit value (61 ° C.), the arithmetic processing unit 61 performs an operation of increasing the discrete value of the output frequency currently specified by one step. Thereby, since the discharge flow rate of the circulation pump 30 increases by one step, the temperature of the outlet water of the auxiliary hot water supply means 3 is lowered. The operation of increasing the discrete value of the output frequency by one step is continued until the outlet water temperature of the auxiliary hot water supply means 3 becomes equal to or lower than the upper limit value (61 ° C.) of the target range.

  Therefore, when the outlet water temperature of the auxiliary hot water supply means 3 deviates from the target range (59 ° C. to 61 ° C.), the feedback control operates the discrete value of the output frequency in preference to the feed forward control.

  In the present embodiment, even if the heating capacity of the auxiliary hot water supply means 3 or the discharge capacity of the circulation pump 30 varies, the feed forward control cannot feed the water temperature of the auxiliary hot water supply means 3 to the target value. By adding the forward control, it is possible to perform the discharge temperature control of the auxiliary hot water supply means 3 that is stable in the long term.

  In addition, since each of the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 operates, high temperature water is stored in the hot water storage tank 1, so that the incoming water temperature of the auxiliary hot water supply means 3 becomes higher than that at the start of operation. Since the discharge flow rate of the circulation pump 30 set in the feedforward control remains unchanged, the outlet water temperature of the auxiliary hot water supply means 3 increases in the same manner, but the circulation set in the feedforward control by the feedback control. The discharge flow rate of the pump 30 is adjusted.

  Next, another embodiment of the device of the present invention will be described.

  <1> In the above-described embodiment, the control device 6 is provided to perform the on / off control of the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 and the water discharge temperature control of the auxiliary hot water supply means 3, as shown in FIG. In addition, the start / stop control of the heat pump hot water supply means 2 and the circulation pump 20 is performed by the operation value output from the second temperature sensor 19 having the function of the temperature indicating controller, and the start / stop control of the auxiliary hot water supply means 3 is The control device 6 may be used exclusively for controlling the discharge flow rate of the circulation pump 30 by using the operation value output from the first temperature sensor 18 having the function of the indicating controller. In this case, the operation value output from the first temperature sensor 18 needs to be input to the arithmetic processing unit 61, but the operation value output from the second temperature sensor 19 needs to be input to the arithmetic processing unit 61. Absent. Further, when the control device 6 is exclusively used for controlling the discharge flow rate of the circulation pump 30, the control device 6 may be provided in the auxiliary hot water supply means 3.

  <2> Further, in the above embodiment, the discharge flow rate of the circulation pump 30 in the outlet water temperature control of the auxiliary hot water supply means 3 is controlled by controlling the frequency of the AC power supplied to the circulation pump 30. Proportional valves may be provided in either of the pipes 33 and 34 forming the circulation flow path between the means 3 and the hot water storage tank 1, and the opening degree of the proportional valve may be controlled. You may carry out by controlling both the frequency of the alternating current power supplied to this, and the opening degree of this proportional valve.

  <3> Further, in the above embodiment, the first temperature sensor 16 and the second temperature sensor 17 that detect the water temperature of the hot water storage tank 1 do not have the function of the temperature indicating controller, and the determination process by the temperature indicating controller is performed. Although it was the structure performed by the arithmetic processing part 61, as each temperature sensor which detects the water temperature of the hot water storage tank 1, it is the 1st temperature sensor provided with the function of the said temperature indication controller similarly to said another embodiment <1>. 18 and the second temperature sensor 19 may be used to output the operation values (on-off binary information) output from the temperature sensors 18 and 19 to the digital input port of the arithmetic processing unit 61, respectively. In this case, the arithmetic processing unit 61 outputs the operation value received from the first temperature sensor 18 to the auxiliary hot water supply means 3 as a control signal without performing comparison determination between each detected temperature and each set temperature. 2 The operation value received from the temperature sensor 19 is output to the heat pump hot water supply means 2 and the circulation pump 20 as a control signal.

  <4> Further, in the above embodiment, the start / stop control of each operation of the heat pump hot water supply means 2 and the auxiliary hot water supply means 3 is performed based on only the temperature detected by the second temperature sensor 17 in the heat pump hot water supply means 2. In the above description, the control is performed based on only the temperature detected by the first temperature sensor 16, but other conditions may be added in each start / stop control.

  For example, when the energy consumption efficiency (COP) of the heat pump hot water supply means 2 is greatly influenced not only by the incoming water temperature but also by the outside air temperature at the installation location, a second temperature sensor is provided for detecting the outside air temperature. Based on both the temperature detected by the temperature sensor 17 and the outside air temperature, the start / stop control of the operation of the heat pump hot water supply means 2 may be performed.

  <5> Furthermore, in the said embodiment, although the structure shown in FIG. 1 was illustrated as a pipe line structure by which the heat pump hot-water supply means 2 and the auxiliary hot-water supply means 3 are arrange | positioned in parallel with respect to the hot water storage tank 1, heat pump hot-water supply means The pipe configuration in which 2 and the auxiliary hot water supply means 3 are arranged in parallel to the hot water storage tank 1 is not limited to the configuration shown in FIG. For example, as shown in FIG. 4, the inlet 15 is an inlet / outlet 15, the inlet / outlet 15 of the hot water tank 1 and the inlet 21 of the heat pump hot water supply means 2 are connected by a pipe 23, and the outlet of the hot water tank 1 is connected. 14 and the water inlet 31 of the auxiliary hot water supply means 3 may be connected by a pipe 33, and a branch point provided upstream of the circulation pump 20 in the pipe 23 and the water supply source 5 may be connected by a pipe 51. good. Further, as shown in FIG. 4, the second temperature sensor 17 may be attached directly below the wall portion of the hot water storage tank 1 instead of being provided near the inlet / outlet 15 of the conduit 23.

  <6> Furthermore, in the said embodiment, although the one tank type thing was assumed as the hot water storage tank 1, the multiple tank type which connected the several hot water storage tank 1 in series may be sufficient. In this case, the water temperature distribution in the hot water storage tank 1 is formed not only in the vertical direction in each tank but also in the order of arrangement of the tanks, so the first temperature sensor 16 exists in the middle in the order of arrangement. The second temperature sensor may be provided in the tank closest to the water inlet 21 of the heat pump hot water supply means 2.

  The hybrid hot water supply system and its stop control method according to the present invention include an electric hot pump hot water supply means and an auxiliary hot water supply means comprising a combustion hot water heater in parallel with respect to a hot water storage tank that stores hot water and supplies it to a hot water supply load. The present invention can be used for a hybrid hot water supply system arranged and configured.

1: Hot water storage tank 2: Electric heat pump hot water supply means 3: Auxiliary hot water supply means (combustion water heater)
4: Hot water supply load 5: Water supply source 6: Control device 11, 13: Hot water tank water inlet 12, 14: Hot water tank water outlet 15: Hot water tank water inlet (water inlet / outlet)
16: 1st temperature sensor 17: 2nd temperature sensor 18: 1st temperature sensor (temperature indication controller)
19: Second temperature sensor (temperature indicating controller)
20, 30, 40: Circulation pump 21: Water inlet of heat pump hot water supply means 22: Water outlet of heat pump hot water supply means 23, 24, 33, 34, 41, 42, 51: Pipe line 31: Water inlet of auxiliary hot water supply means 32: Water outlet 35 of auxiliary hot water supply means 35: third temperature sensor 36: fourth temperature sensor 61: arithmetic processing section 62: inverter circuit section

Claims (6)

A hot water storage tank that stores hot water and supplies it to a hot water supply load;
Electric heat pump hot water supply means for supplying water to the hot water tank by heating the water supplied from the hot water tank by heat exchange with heat radiation from the condenser of the heat pump circuit,
Auxiliary hot water supply means comprising a combustion hot water machine for heating water supplied from the hot water storage tank and supplying the hot water storage tank,
A first temperature sensor for detecting a water temperature at a high temperature position among two predetermined water temperatures that are different when a water temperature distribution is generated in the hot water storage tank;
A second temperature sensor for detecting a water temperature at a low temperature position of the two predetermined points or a water temperature near the water outlet or the water inlet / outlet provided at the low temperature position;
The auxiliary hot water supply means is controlled to start and stop based on at least the temperature detected by the first temperature sensor,
The heat pump hot water supply means is controlled to start / stop operation based on at least the temperature detected by the second temperature sensor,
When the heat pump hot water supply means and the auxiliary hot water supply means start their respective operations, the water discharge temperature is controlled so that the respective water discharge temperatures become the water discharge set temperatures set separately or in common .
The water temperature control of the auxiliary hot water supply means is
A primary flow rate that sets a circulation flow rate between the auxiliary hot water supply means and the hot water storage tank to a primary circulation flow rate that is determined according to the set water discharge temperature, the detected water temperature of the auxiliary hot water supply means, and the heating capacity of the auxiliary hot water supply means. Control,
When the outlet water temperature of the auxiliary hot water supply unit fluctuates beyond a predetermined error range from the outlet water set temperature, the circulating flow rate at the time of the fluctuation is set in a direction to suppress the fluctuation in preference to the primary control. A hybrid hot water supply system comprising: secondary control for feedback control . The heat pump hot water supply means starts operation when the temperature detected by the second temperature sensor becomes equal to or lower than a predetermined first temperature, and the temperature detected by the second temperature sensor is a predetermined second temperature higher than the first temperature. When it is over, it is controlled to stop driving,
The auxiliary hot water supply means starts operation when a temperature detected by the first temperature sensor becomes equal to or lower than a predetermined third temperature, and a predetermined fourth temperature at which the temperature detected by the first temperature sensor is higher than the third temperature. When it is over, it is controlled to stop driving,
When each of the heat pump hot water supply means and the auxiliary hot water supply means is started, the temperature of each water discharge is set to be different from or higher than the higher one of the second temperature and the fourth temperature. The hybrid hot water supply system according to claim 1, wherein the water discharge temperature is controlled so as to become a water discharge set temperature. The control of the circulation flow rate is performed by inverter control by changing a frequency of AC power supplied to a circulation pump interposed in a pipe line between the auxiliary hot water supply means and the hot water storage tank. The hybrid hot water supply system according to 1 or 2. A hot water storage tank that stores hot water and supplies it to a hot water supply load;
Electric heat pump hot water supply means for supplying water to the hot water tank by heating the water supplied from the hot water tank by heat exchange with heat radiation from the condenser of the heat pump circuit,
Auxiliary hot water supply means comprising a combustion hot water machine for heating water supplied from the hot water storage tank and supplying the hot water storage tank,
A first temperature sensor for detecting a water temperature at a high temperature position among two predetermined water temperatures that are different when a water temperature distribution is generated in the hot water storage tank;
And a second temperature sensor for detecting a water temperature at a low temperature position of the two predetermined points or a water temperature at or near the water outlet / outlet provided at the low temperature position. And
Controlling the start and stop of the operation of the auxiliary hot water supply means based on at least the temperature detected by the first temperature sensor;
Controlling the start and stop of the operation of the heat pump hot water supply means based on at least the temperature detected by the second temperature sensor;
For each of the heat pump hot water supply means and the auxiliary hot water supply means, when each operation is started, the water discharge temperature is controlled so that each water discharge temperature becomes a water discharge set temperature set separately or in common ,
In the water temperature control of the auxiliary hot water supply means,
A primary flow rate that sets a circulation flow rate between the auxiliary hot water supply means and the hot water storage tank to a primary circulation flow rate that is determined according to the set water discharge temperature, the detected water temperature of the auxiliary hot water supply means, and the heating capacity of the auxiliary hot water supply means. Control,
When the outlet water temperature of the auxiliary hot water supply unit fluctuates beyond a predetermined error range from the outlet water set temperature, the circulating flow rate at the time of the fluctuation is set in a direction to suppress the fluctuation in preference to the primary control. An operation control method for a hybrid hot water supply system, wherein secondary control for feedback control is performed . The operation of the heat pump hot water supply means is started when the detected temperature of the second temperature sensor becomes equal to or lower than a predetermined first temperature, and the detected second temperature sensor has a predetermined second temperature higher than the first temperature. When it is over, control to stop,
The operation of the auxiliary hot water supply means is started when the detected temperature of the first temperature sensor becomes equal to or lower than a predetermined third temperature, and the detected fourth temperature is higher than the third temperature. When it is over, control to stop,
When each operation is started with respect to the heat pump hot water supply means and the auxiliary hot water supply means, the respective outlet water temperatures are set separately or in common above the higher one of the second temperature and the fourth temperature. 5. The operation control method for a hybrid hot water supply system according to claim 4, wherein the water discharge temperature is controlled so that the water discharge set temperature is reached. 5. The control of the circulation flow rate is performed by inverter control by changing the frequency of AC power supplied to a circulation pump interposed in a pipe line between the auxiliary hot water supply means and the hot water storage tank. Or the operation control method of the hybrid hot-water supply system of 5.

Images