WO2018096664A1

WO2018096664A1 - Water heater

Info

Publication number: WO2018096664A1
Application number: PCT/JP2016/085099
Authority: WO
Inventors: 謙作畑中; 徹小出
Original assignee: 三菱電機株式会社
Priority date: 2016-11-28
Filing date: 2016-11-28
Publication date: 2018-05-31
Also published as: EP3546846A4; EP3546846B1; JPWO2018096664A1; JP6715948B2; EP3546846A1

Abstract

A control device includes an operation control unit that controls the operations of a compressor, a throttling device, and a transportation device. The operation control unit starts the operation of both the compressor and the transportation device when starting a boiling operation of storing heated water in a tank. The operation control device operates the compressor at a first compressor rotation speed until a predetermined first duration has elapsed from the start of the boiling operation, and operates the compressor at a second compressor rotation speed higher than the first compressor rotation speed after the first duration has elapsed.

Description

Water heater

The present invention relates to a water heater, and more particularly to control of a water heater provided with a refrigerant circuit to which a water circulation circuit is connected.

For example, a heat pump water heater has been proposed that executes control to increase the rotational speed of a pump provided in the water circulation circuit in a step shape when the boiling operation is started (see, for example, Patent Document 1). The heat pump water heater of Patent Document 1 executes this control to shorten the arrival time of the target hot water temperature and prevent overshooting of the hot water temperature with respect to the target hot water temperature.

Japanese Patent Laid-Open No. 2005-140439

When starting the boiling operation, the temperature of the refrigerant, the operation of the equipment, and the like are not stabilized, and the COP ( Coefficient Of Performance) of the water heater tends to decrease. When starting the boiling operation, depending on the operation of various devices provided in the water heater, the reduction of the COP may become larger. When starting the boiling operation, for example, if the number of rotations of the pump is suppressed too much, the COP may be further decreased.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a water heater that can suppress a decrease in COP.

A water heater according to the present invention includes a compressor, a condenser connected to a water circulation circuit, a refrigerant circuit including a throttling device and an evaporator, a tank provided in the water circulation circuit and storing water heated by the condenser. A conveying device provided in the water circulation circuit for conveying water to the tank of the water circulation circuit, a first detection unit for detecting the outside air temperature, and a compressor and a throttling device based on the detected outside air temperature of the first detection unit And a control device that controls the transport device, the control device including an operation control unit that controls operations of the compressor, the squeezing device, and the transport device, and the operation control unit stores the heated water in the tank. When starting the boiling operation, both the compressor and the conveying device are started, and the compressor is first compressed until a predetermined first period elapses from the start of the boiling operation. Operate at machine speed and pass through the first period After, to operate the compressor in a second compressor speed greater than the first compressor speed.

According to the water heater according to the present invention, since it has the above-described configuration, it is possible to suppress a decrease in COP.

It is an example of outline composition of hot water supply machine 100 concerning an embodiment. It is explanatory drawing of the boiling operation of the water heater 100 which concerns on embodiment. It is explanatory drawing of the additional cooking operation of the water heater 100 which concerns on embodiment. It is a functional block diagram of control device Cnt. It is the table with which the compressor rotation speed with which control apparatus Cnt is provided was specified. It is the table with which the rotation speed of conveyance with which control apparatus Cnt is provided was specified. It is the table with which the 2nd period with which control apparatus Cnt is provided was specified. It is the table with which target hot-water temperature with which the control apparatus Cnt is provided was specified. It is the table with which the 3rd period with which control apparatus Cnt is provided was specified. It is explanatory drawing of the time change of operation | movement of the compressor. It is explanatory drawing of the time change of operation | movement of the conveying apparatus. It is explanatory drawing of the time change of target hot-water temperature. This is a modification when the set rotational speed of the compressor 1 is shifted from the first compressor rotational speed to the second compressor rotational speed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. In addition, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one. Further, in the following drawings including FIG. 1, the same reference numerals denote the same or equivalent parts, and this is common throughout the entire specification. Furthermore, the forms of the constituent elements shown in the entire specification are merely examples, and are not limited to these descriptions.

Embodiment.
FIG. 1A is a schematic configuration example diagram of a water heater 100 according to an embodiment. The configuration of the water heater 100 will be described with reference to FIG. 1A.

[Description of configuration]
The water heater 100 includes a refrigerant circuit C1, a water circulation circuit C2, a control device Cnt, and various detection units. Moreover, the water heater 100 is connected to the hot water supply utilization part U1, the hot water supply utilization part U2, and the water supply part U3. The hot water supply utilization unit U1 corresponds to, for example, a bath tub. Moreover, the hot water supply utilization part U2 respond | corresponds, for example to a shower, currant, a kitchen faucet, etc. Furthermore, the water supply unit U3 corresponds to, for example, a water tap connected to a water supply pipe.

In the refrigerant circuit C1, the refrigerant circulates. As the refrigerant, for example, a carbon dioxide refrigerant can be employed. The refrigerant circuit C1 includes a compressor 1 that compresses the refrigerant, a heat exchanger 2 that functions as a condenser, a throttling device 3 that functions to depressurize the refrigerant, and a heat exchanger 4 that functions as an evaporator. The heat exchanger 4 is provided with a blower 4 A that supplies air to the heat exchanger 4.
The heat exchanger 2 includes a refrigerant channel through which a refrigerant flows and a water channel through which water flows. The heat exchanger 2 is configured so that heat can be exchanged between the refrigerant flowing through the refrigerant flow path and the water flowing through the water flow path. The refrigerant circuit C1 is connected to the refrigerant flow path of the heat exchanger 2, and the water circulation circuit C2 is connected to the water flow path of the heat exchanger 2. The heat exchanger 2 condenses the refrigerant flowing through the refrigerant flow path. The heat exchanger 2 can be composed of, for example, a double pipe heat exchanger.

Water is circulated in the water circulation circuit C2. The water circulation circuit C2 includes a water flow path of the heat exchanger 2, a flow path switching device 6A, a mixing circuit 6B, a tank 7 for storing water, a heat exchanger 8, and a flow path switching device 9. The water circulation circuit C2 includes a transport device 5 that transports water to the tank 7 and a transport device 10 that transports water to the hot water supply utilization unit U1. Further, the water circulation circuit C2 includes a pipe P1 to a pipe P16. The conveyance apparatus 5 and the conveyance apparatus 10 can be comprised with the pump which conveys water, for example.

The flow path switching device 6A can be constituted by a four-way valve, for example. The flow path switching device 6A includes four ports through which water flows. The flow path switching device 6A includes a first port a, a second port b, a third port c, and a fourth port d. The first port a of the flow path switching device 6A is connected to the pipe P3. The second port b of the flow path switching device 6A is connected to the pipe P4. The third port c of the flow path switching device 6A is connected to the pipe P2. The fourth port d of the flow path switching device 6A is connected to the pipe P8. The flow path switching device 6A can form a first flow path that connects the third port c and the fourth port d. Moreover, the flow path switching device 6A can form a second flow path that connects the first port a and the second port b. That is, the channel switching device 6A is configured to selectively switch between the first channel and the second channel.

The mixing circuit 6B is a circuit having a function of mixing heated water and water supplied from the water supply unit U3. The mixing circuit 6B includes a channel switching device 6B1 and a channel switching device 6B2. The flow path switching device 6B1 and the flow path switching device 6B2 can be configured by, for example, a three-way valve.
The flow path switching device 6B1 includes a first port a, a second port b, and a third port c. The flow path switching device 6B2 includes a first port a, a second port b, and a third port c.

The first port a of the flow path switching device 6B1 is connected to the pipe P10. The second port b of the flow path switching device 6B1 is connected to the third port c of the flow path switching device 6B2. The third port c of the flow path switching device 6B1 is connected to the second port b of the flow path switching device 6B2. The first port a of the flow path switching device 6B2 is connected to the pipe P12. A pipe P11 is connected to a pipe connecting the second port b of the flow path switching device 6B1 and the third port c of the flow path switching apparatus 6B2.

The tank 7 stores the water heated by the heat exchanger 2. The tank 7 is connected to the pipe P3, the pipe P5, the pipe P6, and the pipe P7.
The heat exchanger 8 includes a first water channel to which the pipes P8 and P9 are connected, and a second water channel to which the pipes P12 and P13 are connected. The heat exchanger 2 is configured to exchange heat between water flowing through the first water flow path and water flowing through the second water flow path.

The flow path switching device 9 can be constituted by a three-way valve, for example. The flow path switching device 9 includes a first port a, a second port b, and a third port c. The first port a of the flow path switching device 9 is connected to the pipe P16. The second port b of the flow path switching device 9 is connected to the pipe P9. The third port c of the flow path switching device 9 is connected to the pipe P6. The flow path switching device 9 can form a third flow path that connects the first port a and the second port b. Further, the flow path switching device 9 can form a fourth flow path that connects the first port a and the third port c. That is, the flow path switching device 9 is configured to selectively switch between the third flow path and the fourth flow path.

The pipe P1 connects the water discharge side of the transport device 5 and the water flow path of the heat exchanger 2.
The pipe P2 connects the water channel of the heat exchanger 2 and the third port c of the channel switching device 6A.
The pipe P3 connects the first port a of the flow path switching device 6A and the tank 7.
The pipe P4 connects the second port b of the flow path switching device 6A and the pipe P1.
The pipe P5 connects the pipe P8 and the tank 7. The pipe P5 connects the pipe P8 and the mixing circuit 6B.

The pipe P6 connects the tank 7 and the third port c of the flow path switching device 9.
The pipe P7 connects the tank 7 and the pipe P11.
The pipe P8 connects the fourth port d of the flow path switching device 6A and the pipe P5. The pipe P8 connects the fourth port d of the flow path switching device 6A and the first water flow path of the heat exchanger 8.
The pipe P9 connects the first water flow path of the heat exchanger 8 and the second port b of the flow path switching device 9.

The pipe P10 connects the hot water supply utilization unit U2 and the first port a of the flow path switching device 6B1 of the mixing circuit 6B.
The pipe P11 connects the water supply unit U3 and a pipe between the second port b of the flow path switching device 6B1 of the mixing circuit 6B and the third port c of the flow path switching apparatus 6B2. The pipe P11 is connected to the pipe P7. Water is supplied to the mixing circuit 6B and the tank 7 through the pipe P11.

The pipe P12 connects the first port a of the flow path switching device 6B2 of the mixing circuit 6B and the second water flow path of the heat exchanger 8. The pipe P12 connects the first port a of the flow path switching device 6B2 of the mixing circuit 6B and the pipe P15.
The pipe P13 connects the water discharge side of the transport apparatus 10 and the second water flow path of the heat exchanger 8.
The pipe P14 connects the water suction side of the transport apparatus 10 and the hot water supply utilization unit U1.
The pipe P15 connects the pipe P12 and the hot water supply utilization unit U1.
The pipe P16 connects the water suction side of the transport device 5 and the first port a of the flow path switching device 9.

The first detection unit 10A is a temperature sensor that detects the outside air temperature. The second detection unit 10 B is a temperature sensor that detects the refrigerant temperature on the discharge side of the compressor 1. The third detection unit 10 C is a temperature sensor that detects the heat medium temperature at the outlet of the heat exchanger 2.
The fourth detection unit 10 D is a temperature sensor that detects the temperature of the water stored in the tank 7. The fourth detection unit 10 D can also be used to calculate the amount of water stored in the tank 7. For example, the fourth detection unit 10 D can be configured by a plurality of temperature sensors arranged in the vertical direction of the tank 7.

The detection results of the first detection unit 10A to the fourth detection unit 10D are output to the control device Cnt to control the compressor 1, the conveyance device 5, the conveyance device 10, and the like.

Each functional unit included in the control device Cnt is configured with dedicated hardware or MPU (Micro Processing Unit) that executes a program stored in a memory. When the control device Cnt is dedicated hardware, the control device Cnt is, for example, a single circuit, a composite circuit, an ASIC (application-specific integrated circuit), an FPGA (field-programmable gate array), or a combination thereof. Applicable. Each functional unit realized by the control device Cnt may be realized by individual hardware, or each functional unit may be realized by one piece of hardware. When the control device Cnt is an MPU, each function executed by the control device Cnt is realized by software, firmware, or a combination of software and firmware. Software and firmware are described as programs and stored in a memory. The MPU implements each function of the control device Cnt by reading and executing a program stored in the memory. The memory is a nonvolatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, or an EEPROM.

[Description of operation]
FIG. 1B is an explanatory diagram of the boiling operation of the water heater 100 according to the embodiment.
The water heater 100 can perform a boiling operation in which water is boiled by the heat exchanger 2 and stored in the tank 7. During the boiling operation, the control device Cnt operates the compressor 1 and circulates the refrigerant in the refrigerant circuit C1. Here, at the start of the boiling operation, the controller Cnt sets the rotation speed of the compressor 1 to a first compressor rotation speed described later.
Further, the controller Cnt operates the transport device 5 during the boiling operation. Here, at the start of the boiling operation, the control device Cnt sets the rotational speed of the transport device 5 to a first transport rotational speed described later. During the boiling operation, the control device Cnt switches the flow path switching device 6A to the first flow path, and switches the flow path switching device 9 to the fourth flow path. Thereby, the water of the water circulation circuit C2 flows in the order of the transport device 5, the heat exchanger 2, the flow path switching device 6A, the tank 7, and the flow path switching device 9, and returns to the transport device 5.

FIG. 1C is an explanatory diagram of the additional cooking operation of the water heater 100 according to the embodiment.
The water heater 100 can also perform other operations of the boiling operation. Here, the additional cooking operation will be described as an example.
The additional cooking operation is an operation in which the water stretched in the hot water supply utilization unit U1 (bath) is heated again. In the additional cooking operation, the control device Cnt may stop the compressor 1 or may operate it. Further, in the additional cooking operation, the control device Cnt operates the transport device 5 and the transport device 10. In the additional cooking operation, the control device Cnt switches the flow path switching device 6A to the second flow path, and switches the flow path switching device 9 to the third flow path. Thereby, the water that has flowed out of the transfer device 5 of the water circulation circuit C2 flows through the flow path switching device 6A, the tank 7, the heat exchanger 8, and the flow path switching device 9, and returns to the transfer device 5. On the other hand, the water that has flowed out of the transfer device 10 of the water circulation circuit C2 is heated to the water flowing through the first water flow path of the heat exchanger 8, and then supplied to the hot water supply utilization unit U1 through the pipe P15.

[Regarding the function of the control device Cnt]
FIG. 2 is a functional block diagram of the control device Cnt.

The control device Cnt includes a heat amount acquisition unit 90A, a heat storage amount acquisition unit 90B, a first rotation speed acquisition unit 90C, and a second rotation speed acquisition unit 90D. The control device Cnt includes a period acquisition unit 90E, a tapping temperature information acquisition unit 90F, and an opening degree acquisition unit 90G. Furthermore, the control device Cnt includes an operation control unit 90H and a storage unit 90I.

The heat quantity acquisition unit 90A of the control device Cnt acquires data related to the heat quantity of the water stored in the tank 7. The data relating to the amount of heat of water corresponds to the amount of heat of the remaining hot water, which is the amount of heat of water in the tank 7. The calorie | heat amount acquisition part 90A acquires the remaining hot water calorie | heat amount based on the detected temperature of 4th detection part 10D.

The heat storage amount acquisition unit 90B of the control device Cnt acquires data (target heat storage amount) related to the target value of the total heat storage amount (total heat amount) of the water stored in the tank 7. Data relating to the target value of the total heat storage amount of water corresponds to the target heat storage amount in the tank 7. The heat storage amount acquisition unit 90B calculates a target value of the total heat storage amount of water stored in the tank 7 based on, for example, the heat amount of water used in the hot water supply utilization unit U1, the hot water supply utilization unit U2, and the like. The heat storage amount acquisition unit 90B acquires data regarding the calculated target value as the target heat storage amount.

The first rotation speed acquisition unit 90C of the control device Cnt acquires the first compressor rotation speed and the second compressor rotation speed based on the remaining hot water heat amount, the target heat storage amount, and the detected outside air temperature. . The first rotation speed acquisition unit 90C acquires the remaining hot water heat amount from the heat amount acquisition unit 90A, acquires the target heat storage amount from the heat storage amount acquisition unit 90B, and acquires the detected outside air temperature from the first detection unit 10A. The first compressor rotation speed and the second compressor rotation speed are predetermined constant values. Further, the second compressor rotational speed is larger than the first compressor rotational speed. Specific acquisition means for the first compressor speed and the second compressor speed will be described later with reference to FIG.

The second rotation speed acquisition unit 90D of the control device Cnt acquires the first transfer rotation speed and the second transfer rotation speed based on the remaining hot water heat amount, the target heat storage amount, and the detected outside air temperature. The second rotation speed acquisition unit 90D acquires the remaining hot water heat amount from the heat amount acquisition unit 90A, acquires the target heat storage amount from the heat storage amount acquisition unit 90B, and acquires the detected outside air temperature from the first detection unit 10A. The first conveyance rotation number is a predetermined constant value. On the other hand, the second conveyance rotation number is not limited to a predetermined constant value, and may be a fluctuation value that changes with time. In addition, the first transport rotational speed is smaller than the second transport rotational speed. This magnitude relationship is satisfied regardless of whether the second conveyance rotation number is a constant value or a fluctuation value. Specific acquisition means for the first transport rotation speed and the second transport rotation speed will be described later with reference to FIG. 4A.

The period acquisition unit 90E of the control device Cnt can acquire the first period stored in advance in the storage unit 90I from the storage unit 90I.

Further, the period acquisition unit 90E acquires the second period based on the remaining hot water heat amount, the target heat storage amount, and the detected outside air temperature. The period acquisition unit 90E acquires the remaining hot water heat amount from the heat amount acquisition unit 90A, acquires the target heat storage amount from the heat storage amount acquisition unit 90B, and acquires the detected outside air temperature from the first detection unit 10A. Specific means for acquiring the second period will be described later with reference to FIG. 4B.

The hot water temperature information acquisition unit 90F of the control device Cnt acquires the first target hot water temperature and the second target hot water temperature based on the remaining hot water amount, the target heat storage amount, and the detected outside air temperature. For example, when the detected outside air temperature becomes low as in winter, the first target hot water temperature and the second target hot water temperature are increased accordingly. The hot water temperature information acquisition unit 90F acquires the detected outside air temperature from the first detection unit 10A. Further, the hot water temperature information acquisition unit 90F acquires a third period in which the target hot water temperature is set to the first target hot water temperature based on the remaining hot water heat amount, the target heat storage amount, and the detected outside air temperature.

The opening degree acquisition unit 90G of the control device Cnt determines the first opening degree that is the target opening degree of the expansion device 3 based on the first compressor rotation speed and the target hot water temperature at the start of the boiling operation. get. The opening degree obtaining unit 90G obtains the first compressor rotational speed from the first rotational speed obtaining unit 90C, and obtains the target hot water temperature from the hot water temperature information obtaining unit 90F. When a predetermined time has elapsed since the start of the heating operation, the opening degree acquiring unit 90G is based on the refrigerant temperature discharged from the compressor 1 and is the second opening that is the target opening degree of the expansion device 3. Get the opening. That is, the opening degree acquisition unit 90G acquires the second opening degree based on the temperature detected by the second detection unit 10B.

The operation control unit 90H of the control device Cnt controls the rotational speed of the compressor 1, the opening degree of the expansion device 3, the rotational speed of the transport device 5, and the rotational speed of the transport device 10. In addition, the operation control unit 90H switches the rotation speed of the blower 4A, the flow path of the flow path switching device 6A, the flow path switching of the mixing circuit 6B (the flow path switching device 6B1 and the flow path switching device 6B2), and the flow The switching of the flow path of the path switching device 9 is controlled.

Various data are stored in the storage unit 90I of the control device Cnt.

[About the first compressor speed and the second compressor speed]
FIG. 3 is a table provided in the control device Cnt, in which the compressor rotational speed is specified.
The control device Cnt includes a first table in which the first compressor rotational speed is specified and a second table in which the second compressor rotational speed is specified. In the first table and the second table, compressor rotational speeds that satisfy the following relationship are specified.

In the first table, a plurality of heat amount difference values corresponding to the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount which is the heat amount of the water in the tank 7 are specified. As the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of the water in the tank 7, increases, the heat difference value also increases. Here, the calorific value difference value can be defined by a numerical value determined based on the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of the water in the tank 7. For example, if the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of water in the tank 7, is a numerical value within a predetermined first range, the heat amount difference value is zero. That is, in this case, the control device Cnt refers to the cell in the column “0” in the first table of FIG. Further, for example, if the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of the water in the tank 7, is a numerical value within a predetermined second range that is larger than the first range. The calorie difference value is 100. That is, in this case, the control device Cnt refers to the cell in the column “100” in the first table of FIG. Here, as an example, five different heat quantity difference values are specified.
In the first table, a plurality of outside air temperature values corresponding to the detected outside air temperature are specified. Here, the outside air temperature value can be defined by a numerical value determined based on the detected outside air temperature. For example, if the detected outside air temperature is 40 degrees or less and higher than 25 degrees, the outside air temperature value is 40. That is, in this case, the control device Cnt refers to the cell in the row “40” in the first table of FIG. For example, if the detected outside air temperature is 25 degrees or less and higher than 16 degrees, the outside air temperature value is 25. That is, in this case, the control device Cnt refers to the cell in the row “25” in the first table of FIG. Here, as an example, six different outside air temperature values are specified. Accordingly, 5 × 6 = 30 first compressor rotation speeds are specified in the first table. In addition, the 3rd table, the 4th table, the 5th table, the 6th table, the 7th table, and the 8th table demonstrated based on FIG. 4A, FIG. 4B, FIG. 5A, and FIG. 5B mentioned later. Is also provided with the same format as the first table. That is, for each of these tables, a plurality of (for example, five) heat amount difference values corresponding to the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount that is the heat amount of the water in the tank 7 are specified. A plurality of (for example, six) outside air temperature values corresponding to the detected outside air temperature are specified. 4A, 4B, 5A, and 5B, the definition of the calorific value difference and the outside air temperature value and the explanation of the calorie difference value and the outside air temperature value described based on FIG. 3 are applied. be able to.

The first compressor rotation speed increases as the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of water in the tank 7, increases. That is, when the outside air temperature value is constant, the first compressor rotation speed increases as the heat difference value increases. When the outside air temperature value is constant, the value is larger as the first compressor speed specified on the right side of the first table is higher.

Also, the first compressor rotation speed increases as the detected outside air temperature decreases. That is, when the heat difference value is constant, the first compressor rotation speed increases as the outside air temperature value decreases. In the case where the calorific value difference is constant, the value is larger as the first compressor speed specified on the lower side of the first table.

Also in the second table, the second compressor rotational speed is specified in the same manner as the first table. In the second table, a plurality of heat amount difference values corresponding to the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount which is the heat amount of the water in the tank 7 are specified. Here, as an example, five different heat quantity difference values are specified. In the second table, a plurality of outside air temperature values corresponding to the detected outside air temperature are specified. Here, as an example, eight different outside air temperature values are specified. Therefore, 5 × 8 = 40 second compressor rotation speeds are specified in the second table.

The second compressor rotational speed increases as the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of water in the tank 7, increases. That is, when the outside air temperature value is constant, the second compressor rotation speed increases as the heat quantity difference value increases.
Further, the second compressor rotational speed is larger as the detected outside air temperature is lower. That is, when the calorific value difference value is constant, the second compressor rotation speed increases as the outside air temperature value decreases.

During the period when the boiling operation is not started, it is difficult to increase the efficiency of converting the work of the compressor 1 into the amount of heat of water stored in the tank 7. This is because the temperature of the refrigerant and the operation of various devices are not stabilized at the beginning of the boiling operation. Therefore, when the controller Cnt starts the boiling operation, the rotational speed of the compressor 1 is suppressed as the first compressor rotational speed, and the rotational speed of the compressor 1 is set to the second rotational speed after the first period has elapsed. By executing the control to increase the compressor rotational speed, it is possible to suppress the decrease in COP.

Numeral values that can improve the COP of the water heater 100 under various circumstances are adopted for the compressor rotation speeds specified in the first table and the second table. In the embodiment, various situations are determined based on the detected outside air temperature and the difference between the target heat storage amount and the remaining hot water heat amount. In the embodiment, a situation of 5 × 8 = 40 is assumed. When the control device Cnt operates the compressor 1 at the compressor rotational speed corresponding to each situation, the water heater 100 can realize a boiling operation with a high COP even under various situations.

[About the first conveyance rotation speed and the second conveyance rotation speed]
FIG. 4A is a table provided with the control device Cnt, in which the number of conveyance rotations is specified.
The control device Cnt includes a third table in which the first transfer rotation speed is specified and a fourth table in which the second transfer rotation speed is specified. In the third table and the fourth table, the number of conveyance rotations satisfying the following relationship is specified.

The first transfer rotational speed is larger as the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of water in the tank 7, is smaller. That is, when the outside air temperature value is constant, the first transfer rotation speed increases as the calorific value difference value decreases.
In addition, the first transfer rotation speed is larger as the detected outside air temperature is higher. That is, when the calorific value difference value is constant, the first transfer rotation speed increases as the outside air temperature value increases.

The second conveyance rotation speed increases as the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of water in the tank 7, is smaller. That is, when the outside air temperature value is constant, the second conveyance rotation speed increases as the calorific value difference value decreases.
In addition, the second conveyance rotation speed increases as the detected outside air temperature increases. That is, when the calorific value difference value is constant, the second transfer rotational speed increases as the outside air temperature value increases.

FIG. 4B is a table with which the second period is specified, which is included in the control device Cnt.
The control device Cnt includes a fifth table in which the second period is specified. In the fifth table, a second period that satisfies the following relationship is specified.

The second period is shorter as the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of water in the tank 7, is smaller. That is, when the outside air temperature value is constant, the second period becomes shorter as the calorific value difference value is smaller.
The second period is shorter as the detected outside air temperature is higher. That is, when the calorific value difference value is constant, the second period is shorter as the outside air temperature value is higher.

When the second conveyance rotation number is a variable value, the control device Cnt acquires the initial value of the second conveyance rotation number based on the remaining hot water heat amount, the target heat storage amount, and the detected outside air temperature. Then, when a predetermined condition is satisfied, the control device Cnt performs, for example, a variation control that varies the conveyance rotation number, and varies the second conveyance rotation number. As the variation control, for example, PID control ( Proportional-Integral-Differential Controller ) can be employed. In addition, it is not limited to PID control, P control or PI control may be sufficient. Here, the predetermined condition may be, for example, that the detected temperature (hot water temperature) of the third detection unit 10C exceeds a predetermined target hot water temperature. That is, the control device Cnt shifts to fluctuation control when the temperature detected by the third detector 10C (the temperature of the hot water) exceeds the first target hot water temperature or the second target hot water temperature. As a result, the rotational speed of the transport device 5 changes from the initial value of the second transport rotational speed.

When the rotation speed of the transport device 5 is suppressed or the transport device 5 is kept stopped in a period that is shortly after starting the boiling operation, the acquisition efficiency of the amount of heat supplied from the refrigerant circuit C1 is reduced. There is. That is, it is difficult to increase the efficiency of converting the work of the compressor 1 into the amount of heat of water stored in the tank 7. Therefore, when the control device Cnt starts the boiling operation, the start of the operation of the compressor 1 and the operation of the transfer device 5 can be suppressed, thereby suppressing the decrease in COP of the water heater 100.

The numerical values that can improve the COP of the water heater 100 under various circumstances are adopted for the pump rotation speeds specified in the third table and the fourth table. For the period specified in the fifth table, a numerical value that can improve the COP of the water heater 100 under various circumstances is adopted. In the embodiment, various situations are determined based on the detected outside air temperature and the difference between the target heat storage amount and the remaining hot water heat amount. In the embodiment, a situation of 5 × 8 = 40 is assumed. The controller Cnt operates the transfer device 5 in the second period corresponding to the number of rotations of the pump corresponding to each situation and the hot water heater 100 has a high COP even in various situations. Can be realized.

[First target hot water temperature and second target hot water temperature]
FIG. 5A is a table with which the target hot water temperature is specified, which is included in the control device Cnt.
The control device Cnt includes a sixth table in which the first target hot water temperature is specified and a seventh table in which the second target hot water temperature is specified. In the sixth table and the seventh table, the first target hot water temperature and the second target hot water temperature satisfying the following relationship are specified.

The first target hot water temperature is higher as the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of water in the tank 7, is larger. That is, when the outside air temperature value is constant, the first target hot water temperature is higher as the calorie difference value is larger.
The first target hot water temperature is higher as the detected outside air temperature is lower. That is, when the calorific value difference value is constant, the first target hot water temperature is higher as the outside air temperature value is smaller.

The second target hot water temperature is higher as the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of water in the tank 7, is larger. That is, when the outside air temperature value is constant, the second target hot water temperature is higher as the calorie difference value is larger.
The second target hot water temperature is higher as the detected outside air temperature is lower. That is, when the calorific value difference value is constant, the second target hot water temperature is higher as the outside air temperature value is smaller.

FIG. 5B is a table with which the third period is specified, which is included in the control device Cnt.
The control device Cnt includes an eighth table in which the third period is specified. In the eighth table, a third period that satisfies the following relationship is specified.

The third period is longer as the difference between the target heat storage amount in the tank 7 and the remaining hot water heat amount, which is the heat amount of water in the tank 7, is larger. That is, when the outside air temperature value is constant, the third period becomes longer as the calorific value difference is larger.
The third period is longer as the detected outside air temperature is lower. That is, when the calorific value difference value is constant, the third period becomes longer as the outside air temperature value is lower.

Here, the effect will be explained using winter as an example. If the target hot water temperature (corresponding to the first target hot water temperature) is suppressed during the period when the boiling operation is not started, the opening degree of the expansion device 3 becomes too large, and the refrigerant discharged from the compressor 1 The temperature is unlikely to increase, and the COP of the water heater 100 may decrease. Therefore, when the control device Cnt starts the boiling operation, it is possible to suppress the decrease in COP of the water heater 100 by setting the target hot water temperature in consideration of the detected outside air temperature. In addition, when the control device Cnt starts the boiling operation, the decrease in COP of the water heater 100 is suppressed by setting the target hot water temperature in consideration of the difference between the target heat storage amount and the remaining hot water heat amount. be able to.

For each target hot water temperature specified in the sixth table and the seventh table, a numerical value capable of improving the COP of the water heater 100 under various circumstances is adopted. During the period specified in the eighth table, a numerical value that can improve the COP of the water heater 100 under various circumstances is adopted. In the embodiment, various situations are determined based on the detected outside air temperature and the difference between the target heat storage amount and the remaining hot water heat amount. In the embodiment, a situation of 5 × 8 = 40 is assumed. The controller Cnt sets the target hot water temperature corresponding to each situation and the third period corresponding to each situation, so that the water heater 100 can realize a boiling operation with a high COP even under various situations.

[Operation of compressor 1 in boiling operation]
FIG. 6A is an explanatory diagram of the change over time of the operation of the compressor 1.
Note that time t = 0 in FIG. 6A corresponds to the start of the boiling operation.
Further, time t = t1 in FIG. 6A corresponds to the end of the first period of the boiling operation.
The compressor 1 operates at the first compressor speed during the first period. When the first period elapses, the compressor 1 operates at a second compressor rotational speed that is greater than the first compressor rotational speed.

[Operation of transfer device 5 in boiling operation]
FIG. 6B is an explanatory diagram of the change over time of the operation of the transport device 5.
Note that time t = 0 in FIG. 6B corresponds to the start of the boiling operation.
Further, time t = t2-1 in FIG. 6B corresponds to the end of the second period of the boiling operation.
Further, the time t = t2-2 in FIG. 6B corresponds to the time when the detected temperature (hot water temperature) of the third detection unit 10C exceeds the first target hot water temperature. Note that FIG. 6B illustrates an example in which the second period is shorter than the third period.
The conveyance device 5 operates at the first conveyance rotation number during the second period. When the second period elapses, the transport device 5 starts operation at a second transport rotational speed that is smaller than the first transport rotational speed. And when the detection temperature (hot water temperature) of the 3rd detection part 10C exceeds 1st target hot water temperature, the rotation speed of the conveying apparatus 5 fluctuates from 2nd conveyance rotation speed.

[Changes in target hot water temperature over time during boiling operation]
FIG. 6C is an explanatory diagram of a change over time in the target hot water temperature.
Note that time t = 0 in FIG. 6C corresponds to the start of the boiling operation.
Further, time t = t3 in FIG. 6C corresponds to the end of the third period of the boiling operation.
The control device Cnt sets the set value of the target hot water temperature as the first target hot water temperature during the third period. And control apparatus Cnt makes the setting value of target hot-water temperature the 2nd target hot-water temperature larger than 1st target hot-water temperature, when the 3rd period passes.

FIG. 7 is a modified example when the set rotational speed of the compressor 1 is shifted from the first compressor rotational speed to the second compressor rotational speed. The control device Cnt may increase the set rotational speed of the compressor 1 stepwise from the first compressor rotational speed to reach the second compressor rotational speed at the end of the first period. . The same applies to the operation of the transport device 5.

1 compressor, 2 heat exchanger, 3 expansion device, 4 heat exchanger, 4A blower, 5 transport device, 6A flow switching device, 6B mixing circuit, 6B1 flow switching device, 6B2 flow switching device, 7 tank, 8 heat exchanger, 9 flow path switching device, 10 transport device, 10A first detection unit, 10B second detection unit, 10C third detection unit, 10D fourth detection unit, 90A heat quantity acquisition unit, 90B heat storage Quantity acquisition unit, 90C first rotation number acquisition unit, 90D second rotation number acquisition unit, 90E period acquisition unit, 90F hot water temperature information acquisition unit, 90G opening degree acquisition unit, 90H operation control unit, 90I storage unit, 100 Water heater, C1 refrigerant circuit, C2 water circulation circuit, Cnt control device, P1 piping, P2 piping, P3 piping, P4 piping, P5 piping, P6 piping, P7 piping, 8 piping, P9 pipe, P10 pipe, P11 pipe, P12 pipe, P13 pipe, P14 pipe, P15 pipe, P16 pipe, U1 hot water utilization unit, U2 hot water usage part, U3 water supply unit.

Claims

A refrigerant circuit including a compressor, a condenser connected to a water circulation circuit, a throttling device and an evaporator;
A tank that is provided in the water circulation circuit and stores water heated by the condenser;
A conveying device provided in the water circulation circuit, for conveying water to the tank of the water circulation circuit;
A first detector for detecting the outside air temperature;
A control device for controlling the compressor, the expansion device, and the transport device based on the detected outside air temperature of the first detection unit;
With
The control device includes:
An operation control unit for controlling operations of the compressor, the squeezing device, and the conveying device;
The operation controller is
When starting the boiling operation to store the water heated in the tank, start both the compressor and the transport device,
Until the predetermined first period has elapsed from the start of the boiling operation, the compressor is operated at the first compressor speed,
After the elapse of the first period, the compressor is operated at a second compressor rotational speed that is greater than the first compressor rotational speed.
The first compressor speed is
The hot water heater according to claim 1, wherein a difference between a target heat storage amount in the tank and a remaining hot water heat amount that is a heat amount of water in the tank is larger.
The second compressor speed is
The water heater according to claim 1 or 2, wherein the hot water heater is larger as a difference between a target heat storage amount in the tank and a remaining hot water heat amount that is a heat amount of water in the tank is larger.
The first compressor speed is
The hot water heater according to any one of claims 1 to 3, wherein the detected outside air temperature is lower as it is lower.
The second compressor speed is
The hot water supply apparatus according to any one of claims 1 to 4, wherein the detected outside air temperature is lower as the temperature is lower.
The operation controller is
Until the predetermined second period elapses from the start of the boiling operation, the transport device is operated at the first transport speed,
The hot water heater according to any one of claims 1 to 5, wherein after the elapse of the second period, the transport device is operated at a second transport rotational speed that is smaller than the first transport rotational speed.
The first transfer rotation number is:
The hot water heater according to claim 6, wherein the difference between the target heat storage amount in the tank and the remaining hot water heat amount, which is the heat amount of water in the tank, is larger.
The second transport rotation number is:
The hot water heater according to claim 6 or 7, wherein the difference between the target heat storage amount in the tank and the remaining hot water heat amount that is the heat amount of water in the tank is larger.
The first transfer rotation number is:
The water heater according to any one of claims 6 to 8, wherein the hot water temperature is higher as the detected outside air temperature is higher.
The second transport rotation number is:
The water heater according to any one of claims 6 to 9, wherein the detected outdoor air temperature is higher as it is higher.
The second period is:
The hot water supply apparatus according to any one of claims 6 to 10, wherein the smaller the difference between the target heat storage amount in the tank and the remaining hot water heat amount, which is the heat amount of water in the tank, is shorter.
The second period is:
The hot water supply device according to any one of claims 6 to 11, wherein the detected outside air temperature is higher as it is higher.
The control device includes:
The hot water supply apparatus according to any one of claims 1 to 12, further comprising a calorific value acquisition unit configured to acquire a residual hot water calorific value that is a calorific value of water in the tank.
The control device includes:
The hot water heater according to any one of claims 1 to 13, further comprising a heat storage amount acquisition unit that acquires a target heat storage amount in the tank.
The control device includes:
The first compressor rotation speed and the second compressor rotation speed are acquired based on a remaining hot water heat amount that is a heat amount of water in the tank, a target heat storage amount in the tank, and the detected outside air temperature. The water heater according to any one of claims 1 to 14, further comprising a first rotation speed acquisition unit.
The control device includes:
The second transfer rotational speed is acquired based on the remaining hot water heat quantity that is the heat quantity of water in the tank, the target heat storage quantity in the tank, and the detected outside air temperature. The hot water heater according to any one of claims 6 to 12 and claims 13 to 15 dependent on claims 6 to 12.
The control device includes:
Based on the amount of remaining hot water, which is the amount of water in the tank, the target amount of heat stored in the tank, and the detected outside air temperature, the second period in which the transport device is operated at the first transport speed. The hot water supply apparatus according to any one of claims 6 to 12, 16 and claim 13 to 15 dependent on claim 6 to 12, further comprising a period acquisition unit for acquisition.