JP2010236710A - Hybrid type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To use heating by a gas heating means together so as to excel also in an aspect of running cost while capitalizing on an efficiency of an electric heat pump water heater in accordance with an inflow water temperature, an outside air temperature, and a required tapping temperature. <P>SOLUTION: Based on the inflow water temperature, the outside air temperature, and the required tapping temperature, a temperature of hot water minimizing the running cost is extracted as a set hot water temperature by a set hot water temperature extracting means 25. An electric motor 2 of a compressor is controlled by a compressor control means 29. While the hot water at the set hot water temperature is obtained by operating the electric heat pump water heater with a high coefficient of performance, a flow regulating valve 24 of a gas burner is controlled by a gas supply amount control means 32. The hot water at the set hot water temperature is heated by the gas burner. Thus, the hot water at the required tapping temperature set by a hot water temperature setting unit 20 is obtained. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hybrid type hot water supply apparatus including an electric heat pump water heater and a hot water supply configuration by gas heating means such as a gas burner of a gas instantaneous water heater.

Conventionally, the following is known as a hybrid hot water supply apparatus as described above.
An electric compressor that compresses the refrigerant and heats it to a refrigerant pipe that circulates and flows the refrigerant, a heat exchanger that radiates the heat of the high-temperature refrigerant from the compressor and heats the water flowing in the water supply pipe, An expansion valve that adiabatically expands the refrigerant from the heat exchanger and an evaporator that heats the refrigerant from the expansion valve are provided in that order to form an electric heat pump water heater, and a heating unit that is heated by a gas burner is provided, At the downstream side of the exchanger, a water supply pipe is attached to the heating part so that heat can be transferred, and heated with an electric heat pump water heater with a high coefficient of performance to obtain hot water, the hot water is heated with a gas burner of a gas instantaneous water heater It is comprised so that high temperature hot water may be obtained (refer patent document and FIG. 1).

  JP 2007-255775 A

Although the electric heat pump water heater has excellent efficiency at the time of rating, there is a problem that the efficiency decreases when the outside air temperature is low or the required hot water temperature is high, and the water supplied to the electric heat pump water heater There was a problem that the efficiency fluctuated depending on the temperature of the water, that is, the fluctuation of the water temperature.
On the other hand, in the gas burner of the gas instantaneous water heater, there is little decrease in efficiency when the outside air temperature is low or when the required hot water temperature is high, and there is little fluctuation in efficiency due to fluctuations in the incoming water temperature.
However, in the above conventional example, even when the electric heat pump water heater is operated in a state of high efficiency with high coefficient of performance in obtaining predetermined hot water, its power consumption is more than necessary. This does not take into consideration the power consumption of the electric heat pump water heater and the fuel gas consumption of the gas instantaneous water heater, and there is room for improvement in terms of running cost.

  The present invention has been made in view of such circumstances, and is excellent in running cost while making good use of the efficiency of the electric heat pump water heater in correspondence with the incoming water temperature, the outside air temperature, and the required hot water temperature. Thus, it aims at enabling it to use together the heating by a gas heating means.

In order to achieve the above-described object, the hybrid hot water supply device of the invention according to claim 1
An electric compressor that compresses the refrigerant and heats it to a refrigerant pipe that circulates and flows the refrigerant; and a heat exchanger that dissipates the heat of the high-temperature refrigerant from the compressor and heats the water flowing in the water supply pipe. And an expansion means for adiabatic expansion of the refrigerant from the heat exchanger and an evaporator for heating the refrigerant from the expansion means in that order to constitute an electric heat pump water heater, and heating by the gas heating means In the hybrid hot water supply apparatus provided with a portion, and the water supply pipe is attached downstream of the heat exchanger so that heat can be transferred to the heating unit.
An incoming water temperature sensor for measuring the temperature of water supplied to the electric heat pump water heater,
An outside temperature sensor for measuring the outside temperature;
A first hot water temperature sensor for measuring a temperature of hot water flowing in a water supply pipe between the heat exchanger and the heating unit;
A set hot water temperature table that stores, as the set hot water temperature, the hot water temperature that minimizes the running cost, previously obtained based on the incoming water temperature, the outside air temperature, and the required hot water temperature, as the hot water temperature obtained by the electric heat pump water heater. When,
Hot water detection means for detecting a hot water request and outputting a hot water supply signal;
Hot water supply starting means for starting an electric heat pump water heater in response to a hot water supply signal from the hot water detection means;
Set hot water temperature extraction means for extracting a set hot water temperature from the set hot water temperature table based on the incoming water temperature measured by the incoming water temperature sensor, the outside air temperature measured by the outside air temperature sensor and the required hot water temperature;
Compressor control means for controlling the compressor so that the measured hot water temperature becomes the set hot water temperature by comparing the hot water temperature measured by the first hot water temperature sensor with the set hot water temperature;
Gas heating starting means for starting the gas heating means when the hot water temperature measured by the first hot water temperature sensor reaches a set hot water temperature;
A second hot water temperature sensor for measuring the temperature of the hot water that has passed through the heating section;
Gas supply amount control means for controlling the gas supply amount to the gas heating means so that the temperature of the hot water measured by the second hot water temperature sensor becomes the required hot water temperature.

According to the configuration of the hybrid hot water supply apparatus of the invention according to claim 1, when hot water is supplied, the hot water temperature at which the running cost is minimized is extracted as the set hot water temperature based on the incoming water temperature, the outside air temperature, and the required hot water temperature. While operating an electric heat pump water heater with a high coefficient of performance to obtain hot water at the set hot water temperature, the hot water that has passed through the heat exchanger of the electric heat pump water heater is heated by the gas heating means to obtain hot water at the required hot water temperature. be able to.
Therefore, heating by the gas heating means can be used in combination with the efficiency of the electric heat pump water heater in correspondence with the incoming water temperature, the outside air temperature, and the required hot water temperature, and the running cost can be improved, thereby improving the economy. .

It is a whole schematic block diagram which shows the Example of the hybrid type hot-water supply apparatus which concerns on this invention. It is a block diagram which shows a control system. It is a graph which shows correlation with incoming water temperature, external temperature, and a coefficient of performance. It is a graph which shows correlation with incoming water temperature, external temperature, and a coefficient of performance. It is a graph which shows the correlation with a coefficient of performance and the cost per unit calorie | heat amount. It is a graph which shows the correlation with tapping temperature, outside temperature, and a coefficient of performance.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an overall schematic diagram showing a first embodiment of a hybrid hot water supply apparatus according to the present invention, in which refrigerant is compressed into a closed refrigerant pipe 1 that circulates and flows with refrigerant such as chlorofluorocarbon gas or carbon dioxide gas. Then, the compressor 3 driven by the electric motor 2 to increase the temperature, the heat exchanger 4 that radiates the heat of the high-temperature refrigerant from the compressor 3, and the expansion means that adiabatically expands the refrigerant from the heat exchanger 4 The expansion valve 5 and the evaporator 6 are interposed in that order to constitute an electric heat pump water heater 7. An expansion turbine or the like may be used as the expansion means.

A water supply pipe 8 is introduced into the heat exchanger 4, and the water flowing in the water supply pipe 8 is heated by the heat radiated from the high-temperature refrigerant from the compressor 3.
On the downstream side of the heat exchanger 4, a water supply pipe 8 is attached to a heating unit 10 that constitutes a gas instantaneous water heater 9 so that heat can be transferred.

The gas instantaneous water heater 9 is configured such that a casing 11 is provided with a heating unit 10 and a gas burner 12 as gas heating means provided below the heating unit 10.
An exhaust gas pipe 13 for discharging combustion exhaust gas from the gas burner 12 is connected to an upper portion of the casing 11 and an exhaust fan 14 is attached. An exhaust gas pipe 13 is introduced into the evaporator 6 so that the refrigerant flowing in the evaporator 6 can be heated using the exhaust heat of the gas burner 12.

  On the downstream side of the heating unit 10, the water supply pipe 8 is provided with a tapping sensor 15 as a tapping sensor 15 that senses a tapping request by sensing the flow of water inside and supplies a hot water supply signal. For example, the hot water detection means may be configured to detect that a hot water supply curan has been opened.

An incoming water temperature sensor 16 for measuring the temperature of water supplied to the electric heat pump water heater 7 is provided at a location upstream of the heat exchanger 4 in the water supply pipe 8, and between the heat exchanger 4 and the heating unit 10. Thus, the first hot water temperature sensor 17 for measuring the temperature of hot water flowing through the water supply pipe 8 is provided, and the second hot water for measuring the temperature of the hot water passed through the heating unit 10 is further provided in the water supply pipe 8. A temperature sensor 18 is provided.
In addition, an outside air temperature sensor 19 for measuring the outside air temperature and a hot water temperature setting device 20 for setting a tapping temperature for the gas instantaneous water heater 9 are provided.

  The incoming water temperature sensor 16, the first and second hot water temperature sensors 17, 18, the outside air temperature sensor 19, and the hot water temperature setting device 20 are connected to the controller 21, and the electric motor 2, the blower fan 6 a, and the exhaust fan are connected to the controller 21. 14, an ignition switch 22 for the gas burner 12, and a flow rate adjusting valve 24 interposed in a fuel gas supply pipe 23 connected to the gas burner 12 are connected.

  The controller 21 includes a set hot water temperature extracting means 25, a set hot water temperature table 26, a first comparing means 27, a hot water supply starting means 28, a compressor control means 29, a gas heating starting means 30, a second comparing means 31 and a gas. Supply amount control means 32 is provided.

In the set hot water temperature table 26, as will be described later, the running cost obtained in advance based on the incoming water temperature, the outside air temperature, and the required hot water temperature is minimized as the hot water temperature obtained by the electric heat pump water heater 7. The hot water temperature is stored as the set hot water temperature.
In the set hot water temperature extraction means 25, a set hot water temperature table based on the incoming water temperature measured by the incoming water temperature sensor 16, the outside air temperature measured by the outside air temperature sensor 19, and the required hot water temperature set by the hot water temperature setter 20. The set hot water temperature is extracted from 26.

  In the first comparison means 27, in response to the hot water supply signal from the hot water sensor 15 via the hot water supply starting means 28, the measured hot water temperature by the first hot water temperature sensor 17 and the set hot water temperature extracted by the set hot water temperature extracting means 25. When the measured hot water temperature is lower than the set hot water temperature, a first temperature rise signal is sent to the compressor control means 29, and when the measured hot water temperature is higher than the set hot water temperature, the first temperature drop signal is sent to the compressor control means 29, respectively. It is designed to output. Further, when the hot water temperature measured by the first hot water temperature sensor 17 first reaches the set hot water temperature, an activation signal is output to the gas heating activation means 30.

  In the hot water supply starting means 28, the electric heat pump water heater 7, that is, the electric motor 2 and the blower fan 6a of the compressor 3 is started in response to the hot water supply signal from the hot water sensor 15, and the first comparison means 27 is started. A hot water supply signal is output for startup.

  In the compressor control means 29, the rotational speed of the electric motor 2 is increased by a set amount in response to the first temperature raising signal from the first comparison means 27, and the discharge pressure of the compressor 3 is increased. In response to the first temperature drop signal from the first comparison means 27, the rotational speed of the electric motor 2 is decreased by a set amount so as to reduce the discharge pressure of the compressor 3, that is, the first hot water temperature sensor. The compressor is controlled so that the measured hot water temperature at 17 becomes the set hot water temperature.

  The gas heating starter 30 ignites the ignition switch 22 in response to the start signal from the first comparison unit 27 as the measured hot water temperature measured by the first hot water temperature sensor 17 becomes the set hot water temperature, and exhausts the exhaust gas. The fan 14 is activated, that is, the gas burner 12 is activated. In addition, an activation signal is output to the second comparison means 31.

  In the second comparison means 31, in response to the activation signal from the gas heating activation means 30, the hot water temperature measured by the second hot water temperature sensor 18 and the required hot water temperature set by the hot water temperature setting device 20. When the measured hot water temperature is lower than the required hot water temperature, the gas supply amount control means 32 outputs a second temperature rise signal, and when the measured hot water temperature is higher than the required hot water temperature, the second temperature decrease signal. To output.

  In response to the second temperature rise signal from the second comparison means 31, the gas supply amount control means 32 outputs an opening signal to the flow rate adjustment valve 24, and opens the flow rate adjustment valve 24 by a set opening degree to produce fuel. The gas supply amount is increased, and on the other hand, in response to the second temperature drop signal from the second comparison means 31, a closing signal is output to the flow rate adjusting valve 24, and the flow rate adjusting valve 24 is closed by the set opening degree. The supply amount of the fuel gas is controlled so that the supply amount of the fuel gas is reduced and hot water having the required hot water temperature is obtained.

Next, the creation of the set hot water temperature table 26 will be described using an example.
First, the coefficient of performance (COP) is obtained based on the incoming water temperature and the outside air temperature based on the correlation between the incoming water temperature, the outside air temperature, and the coefficient of performance shown in the graphs of FIGS. The incoming water temperatures in FIGS. 3 and 4 are T1: 10 ° C., T2: 20 ° C., T3: 30 ° C., T4: 40 ° C., T5: 50 ° C., and T6: 60 ° C., respectively.
On the other hand, from the correlation between the coefficient of performance shown in the graph of FIG. 5 and the cost per unit heat quantity, the branch point of the coefficient of performance that is the minimum cost is obtained. According to this graph, while the cost G of the instantaneous gas water heater 9 is constant, the cost E of the electric heat pump water heater 7 changes, and the coefficient of performance at the branch point is 250%, that is, 2. 5 The coefficient of performance at this branching point differs depending on the model of the gas instantaneous water heater 9 and the electric heat pump water heater 7 to be used, and is determined for each model to be used.

  For example, when the incoming water temperature is 20 ° C., as can be seen from the graph of FIG. 3, the outside air temperature is 5 ° C. or higher and the coefficient of performance exceeds 2.5. Based on this bifurcation point 2.5, from the correlation of the tapping temperature, the outside air temperature and the coefficient of performance shown in the graph of FIG. The hot water temperature 50 ° C. is the set hot water temperature. If the outside air temperature is 10 ° C., a hot water temperature of about 57 ° C. is obtained by proportional calculation between the hot water temperatures of 50 ° C. and 60 ° C., and this hot water temperature 57 ° C. becomes the set hot water temperature. The outside air temperatures in FIG. 6 are HT1: 40 ° C., HT2: 50 ° C., and HT3: 60 ° C., respectively.

In addition, when the outside air temperature is 0 ° C., a coefficient of performance of 2.0 is obtained from FIG. 3. When this outside air temperature of 0 ° C. and the coefficient of performance of 2, 0 are applied to FIG. The hot water temperature 50 ° C. is the set hot water temperature.
To sum up these values, when the incoming water temperature is 20 ° C., the set hot water temperature is 50 ° C. when the outside air temperature is 0 ° C., the set hot water temperature is 50 ° C. when the outside air temperature is 5 ° C., and the set hot water temperature is 57 ° C. when the outside air temperature is 10 ° C.
Thus, for example, the set hot water temperature of the outside air temperature changed by 0.2 ° C. is obtained for each incoming water temperature changed by 0.2 ° C., and those values are stored in the set hot water temperature table 26. I will let you.
By adding the required hot water temperature, when the required hot water temperature is lower than the set hot water temperature, hot water is obtained only by the electric heat pump water heater 7.

  With the above configuration, the hot water with the minimum running cost, which is obtained in advance based on the incoming water temperature, the outside air temperature, and the required hot water temperature as the hot water temperature obtained by the electric heat pump water heater 7 in the set hot water temperature table 26. Can be stored as the set hot water temperature, hot water up to the set hot water temperature is obtained by the electric heat pump water heater 7, and hot water at the set hot water temperature is heated by the gas burner 12 to obtain hot water at the required hot water temperature. Thus, hot water having the required hot water temperature can be obtained economically.

  The present invention can also be applied to a case where hot water heated by midnight power is stored in a hot water storage tank. In that case, when the hot water in the hot water storage tank becomes empty or when the temperature of the hot water stored in the hot water storage tank is lower than the set hot water temperature, it is obtained by the gas instantaneous water heater 9.

DESCRIPTION OF SYMBOLS 1 ... Refrigerant piping 3 ... Compressor 4 ... Heat exchanger 5 ... Expansion valve (expansion means)
6 ... Evaporator 7 ... Electric heat pump water heater 8 ... Water supply pipe 10 ... Heating part 12 ... Gas burner (gas heating means)
15 ... Hot water sensor (hot water detection means)
DESCRIPTION OF SYMBOLS 16 ... Incoming water temperature sensor 17 ... 1st hot water temperature sensor 18 ... 2nd hot water temperature sensor 19 ... Outside temperature sensor 25 ... Set hot water temperature extraction means 26 ... Set hot water temperature table 28 ... Hot water supply starting means 29 ... Compressor control means 30 ... Gas heating starting means 32 ... Gas supply amount control means

Claims (1)

An electric compressor that compresses the refrigerant and heats it to a refrigerant pipe that circulates and flows the refrigerant; and a heat exchanger that dissipates the heat of the high-temperature refrigerant from the compressor and heats the water flowing in the water supply pipe. And an expansion means for adiabatic expansion of the refrigerant from the heat exchanger and an evaporator for heating the refrigerant from the expansion means in that order to constitute an electric heat pump water heater, and heating by the gas heating means In the hybrid hot water supply apparatus provided with a portion, and the water supply pipe is attached downstream of the heat exchanger so that heat can be transferred to the heating unit.
An incoming water temperature sensor for measuring the temperature of water supplied to the electric heat pump water heater,
An outside temperature sensor for measuring the outside temperature;
A first hot water temperature sensor for measuring a temperature of hot water flowing in a water supply pipe between the heat exchanger and the heating unit;
A set hot water temperature table that stores, as the set hot water temperature, the hot water temperature that minimizes the running cost, previously obtained based on the incoming water temperature, the outside air temperature, and the required hot water temperature, as the hot water temperature obtained by the electric heat pump water heater. When,
Hot water detection means for detecting a hot water request and outputting a hot water supply signal;
Hot water supply starting means for starting an electric heat pump water heater in response to a hot water supply signal from the hot water detection means;
Set hot water temperature extraction means for extracting a set hot water temperature from the set hot water temperature table based on the incoming water temperature measured by the incoming water temperature sensor, the outside air temperature measured by the outside air temperature sensor and the required hot water temperature;
Compressor control means for controlling the compressor so that the measured hot water temperature becomes the set hot water temperature by comparing the measured hot water temperature with the first hot water temperature sensor and the set hot water temperature;
Gas heating starting means for starting the gas heating means when the hot water temperature measured by the first hot water temperature sensor reaches a set hot water temperature;
A second hot water temperature sensor for measuring the temperature of the hot water that has passed through the heating unit;
Gas supply amount control means for controlling the gas supply amount to the gas heating means so that the temperature of the hot water measured by the second hot water temperature sensor becomes the required hot water temperature;
A hybrid hot water supply apparatus characterized by comprising:

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