JP6774980B2 - Hot water storage system - Google Patents

Description

The present invention relates to a hot water storage type hot water supply system that supplies hot water generated by a heat pump or the like.

In recent years, as a water heater, the introduction of a hot water storage type hot water supply system that stores hot water generated by a heat pump or the like in a hot water storage tank and supplies hot water from the hot water storage tank to a load such as a kitchen, a washroom, or a bath is increasing. The heat pump includes at least a heat exchanger, a compressor, and a water heat exchanger, takes in the heat energy of the outside air inside, and heats the refrigerant (natural refrigerant) via the heat exchanger. The warmed refrigerant is compressed by the compressor to a higher temperature, and the water in the hot water storage tank is heated via a water heat exchanger.

This type of hot water supply system is usually set to perform a series of processes for heating and keeping the water supplied in the hot water storage tank at night when the electricity rate is low. Therefore, it is possible to reduce the utility cost for hot water supply as compared with the instantaneous water heater that heats each time it is used. Further, since the electric power used is basically about the drive source of the compressor, energy saving is realized.

However, since a heat pump is used, it is easily affected by the outside air temperature, and since the hot water storage tank is usually installed outdoors, the heat generation efficiency is significantly reduced, especially during the winter season in cold regions, and the hot water storage tank is inside the hot water storage tank. There was a possibility that heat dissipation loss would occur, such as running out of hot water.

Therefore, conventionally, for example, a hot water storage tank for storing hot water heated by an electric heater (electric heater) and a hot water supply pipe communicating in the hot water storage tank are provided, and the hot water supply pipe is branched at at least one place in the middle. Then, each branch pipe is led to a hot water supply place, and an electric water heater has been proposed in which at least one of the branch pipes is connected to a gas instantaneous water heater (for example, Patent Document). See 1.).

According to this configuration, for example, the temperature of the hot water stored in the hot water storage tank is set to a temperature suitable for use in the kitchen (60 ° C.), and the bathroom is equipped with a gas instantaneous water heater connected to the branch pipe. By additional heating with a hot water supply at a high temperature (80 ° C.), it is possible to supply hot water at a temperature suitable for each purpose to each hot water supply location.

In addition, a hybrid hot water supply system has been proposed that reheats water heaters by adding gas type and kerosene type instantaneous water heaters to water heaters with electric hot water storage tanks, including those that use electricity at midnight (for example, patents). See Reference 2.).

According to this configuration, it is possible to reduce the volume of the conventional hot water storage tank, improve the system efficiency, and minimize the heat loss and the residual hot water loss.

Jikkenhei 5-36242 Gazette Utility model registration No. 3137813

However, the above-mentioned prior art discloses a configuration in which a water heater with an electric water heater and an instantaneous water heater are simply connected, and exclusively claims to improve efficiency by reducing the volume of the hot water storage tank (hot water storage tank). (Patent Document 2) or a hot water storage type electric water heater and an instantaneous water heater are always used in parallel (Patent Document 1). Therefore, in these configurations, the hot water storage type hot water supply is used. The configuration was such that the merits of the system could not be fully demonstrated.

In other words, the major merit of introducing a hot water storage system is that, as mentioned above, water is heated and kept warm at night when electricity charges are low, and the amount of electricity used during the daytime when electricity charges are relatively high is suppressed. .. However, in the above-mentioned prior art, since the instantaneous water heater and the instantaneous water heater are in a state where they can be used at all times when hot water is used, the system configuration does not take into consideration the above-mentioned cost advantage. If the main purpose of the user to switch from the existing instantaneous water heater or instant water heater to the hot water storage system is the above-mentioned price merit, there is an incentive for introduction in the system having the above-mentioned conventional technology. Doesn't work.

By the way, in many cases, the introduction of the hot water storage type hot water supply system is switched from the existing water heater. Water heater installers typically completely remove existing water heaters and install new hot water storage systems, but simply, as in the configuration disclosed in the prior art, simply existing water heaters. When connected to a water heater, if the hot water outlet pressure of the hot water storage type hot water supply system exceeds the maximum inflow pressure allowed on the existing water heater side, the hot water supply pipe may be damaged due to the hot water outlet pressure, which may cause water leakage. there were.

The heat pump is usually installed outdoors. Then, when exhausting, dew condensation occurs on the heat exchanger. When impurities or the like dissolve in this dew and become an acidic liquid, if it drips in the vicinity of the heat pump, it causes corrosion of the gantry on which the heat pump is installed. Therefore, when installing the heat pump, a drain drain pipe is joined to the heat pump so that the water is drained to a region where inconveniences such as corrosion can be avoided. However, in cold regions, the drain drain pipe freezes in winter, which may hinder drainage. Therefore, it is prohibited to join the drain drain pipe. As a result, the installation becomes unstable due to the corrosion of the heat pump mount, and the operation malfunctions. There was a risk of causing it. If the heat pump malfunctions, it may hinder the realization of the desired efficient hot water supply when the hot water storage type electric water heater and the existing water heater are connected and used as in the conventional technique. It was.

Therefore, the present invention is intended to solve the above problems, and is desired efficiently and effectively when a problem such as running out of hot water occurs while maximizing the advantages of introducing the hot water storage type hot water supply system. The purpose is to provide a hot water storage type hot water supply system that can realize hot water supply at temperature.

In order to achieve the above object, the hot water storage type hot water supply system according to the present invention operates another water heater only when the hot water supplied from the hot water storage tank is lower than the set temperature, and the set temperature is achieved. It is characterized by controlling so as to heat the water.

That is, the hot water storage type hot water supply system according to the present invention.
A hot water generator that generates hot water from the supplied water,
A hot water storage unit that stores the generated hot water and discharges the hot water to a load via a hot water supply pipe.
A spare hot water supply pipe that allows at least a direct pressure type or combustion type spare water heater to be connected between the supply pipe and the load.
A detection unit that detects the temperature of hot water in the hot water storage unit,
The hot water discharged from the hot water storage unit is set to a predetermined temperature, and the hot water is supplied to the load via the spare water heater and the spare hot water pipe, and the temperature detected by the detection unit is the set predetermined temperature. When the temperature is lower than the above temperature, the preparatory water heater is operated to generate hot water heated to a predetermined temperature and supply the hot water to the load.
That it has a.

Then, the hot water generation unit is composed of a heat pump that compresses the refrigerant that has absorbed the heat energy of the outside air and returns the refrigerant through the heat exchanger, and the hot water storage unit has the primary side of the hot water generated by the heat exchanger. It is composed of a hot water storage tank connected to a supply pipe and the secondary side is connected to a hot water supply pipe that sends the hot water to a plurality of the loads, and the control unit first sets the temperature of the hot water discharged from the hot water storage tank. When the temperature is set and the temperature of the hot water discharged from the preliminary hot water pipe can be set as the second set temperature lower than the first set temperature, and the temperature detected by the detection unit is less than the second set temperature. To the drain drain pipe that discharges water such as dew that occurs in the recirculation cycle of the heat pump, the preliminary water heater is operated to heat the temperature to the second set temperature so that hot water can be supplied to the load. The most important feature is the installation of an outside temperature sensing type heater that automatically operates when the temperature drops below a predetermined temperature .

According to this configuration, the preliminary water heater operates when the hot water stored in the hot water storage tank is lower than the set temperature desired by the user (in the case of so-called "out of hot water"). As long as the temperature is maintained, the hot water in the hot water storage tank will be supplied exclusively, and it will be possible to make the best use of the hot water generated by the nighttime rate, which has a low electricity rate.

Furthermore, the temperature of hot water for hot water from the hot water storage tank, namely, a first set temperature, the temperature at which the pre-water heater is activated, i.e., by Rukoto provided a predetermined temperature difference between the second set temperature, the It is possible to operate the preliminary water heater each time the temperature drops below the first set temperature to prevent the operation of the preliminary water heater from being repeated frequently.

The control unit may stop the operation of the preliminary water heater when the detection unit detects the first set temperature or higher after the operation of the preliminary water heater.

When the load includes at least a bath, the preliminary water heater has a function of additional cooking with respect to the bath, and the control unit operates the preliminary water heater, the control unit controls the hot water of the bath. The tension and additional hot water may be supplied from the hot water storage tank and re-cooked by the preliminary water heater. In the case of hot water filling and adding hot water, even if the temperature is lower than the second set temperature, it is better to use the hot water in the hot water storage tank and re-cook with the preliminary water heater to prepare the hot water including hot water filling and adding hot water. The overall thermal efficiency is better than replacing all the vessels.

By the way, as described above, when hot water flows from the hot water storage tank to the preliminary water heater, and the allowable inflow pressure of the preliminary water heater is lower than the hot water discharge pressure of the hot water storage tank, simply connecting the two makes it possible to store hot water. Due to the hot water discharge pressure of the tank, the spare water heater (specifically, the can body, piping, etc. in the spare water heater) is exposed to excessive pressure, which may cause damage and cause water leakage.

Therefore, a hot water storage type hot water supply system is provided with a switching three-way valve provided between the supply pipe and the load, and a direct pressure type or combustion type spare where the allowable inflow pressure of water or hot water is lower than the hot water discharge pressure of the hot water storage tank. A flow path interposed for flowing hot water from the hot water storage tank in the hot water supply pipe between the secondary side of the hot water storage tank and the switching three-way valve, and a switching hot water pipe that can be connected to the water heater. A modified three-way valve, a flow path changing pipe one connected to the flow path changing three-way valve and the other connected to the spare water heater.
The temperature of the hot water discharged from the hot water storage tank is set by the detection unit that detects the temperature of the hot water in the hot water storage tank. If the temperature detected by the detection unit is less than the set temperature, the hot water is hot water from the hot water supply pipe. The switching three-way valve is controlled to open and close so as to shut off the hot water supply and operate the preliminary water heater to generate hot water heated to a predetermined temperature and supply hot water to the load from the switching hot water pipe. possess a control unit, wherein the control unit, the flow path changes the three-way valve opening and closing control, the inflow allowable pressure of the pre-water heater, if below the tapping pressure of the hot water storage tank, the flow path changing tube The side is shut off and the hot water supply pipe side is opened, and when the allowable inflow pressure is equal to or higher than the hot water discharge pressure of the hot water storage tank, the flow path changing pipe side is opened and the flow path changing three-way valve is used. The hot water supply pipe side connecting to the switching three-way valve is cut off, the temperature of the hot water discharged from the hot water storage tank is set as the first set temperature, and the temperature of the hot water discharged from the switching hot water pipe is lower than the first set temperature. Each of the two set temperatures can be set, and when the temperature detected by the detection unit is less than the second set temperature, the preliminary water heater is operated to heat the water to the second set temperature to supply hot water to the load. It may be a configuration that enables it .

According to this configuration, the hot water discharged from the hot water storage tank does not flow directly into the spare water heater, and when the set temperature drops, the spare water heater operates in a timely manner. It enables hot water supply at the desired temperature without damage.

When the detection unit detects the set temperature or higher after the preliminary water heater is operated, the control unit stops the operation of the preliminary water heater, controls the opening and closing of the switching three-way valve, and shuts off the switching hot water pipe. Then, the hot water supply pipe may be opened so that the hot water in the hot water storage tank can be supplied to the load again.

The control unit may automatically execute the opening / closing control of the switching three-way valve based on the temperature detected by the detection unit.

According to this configuration, the preliminary water heater operates appropriately according to the set temperature without the user performing the opening / closing operation (switching operation) of the switching three-way valve.

Further, as in the case of the configuration without the switching three-way valve, the load includes at least a bath, the preliminary water heater has a function of reheating the bath, and the control unit controls the preliminary water heater. When activated, the control unit may be re-cooked by the pre-water heater, and when the control unit operates the pre-water heater, the control unit may fill the bath with hot water and The hot water may be supplied from the hot water storage tank.

As described above, depending on the inflow allowable pressure of the preliminary water heater, there are two configurations, one in which the switching three-way valve is interposed and the other in which the switching three-way valve is not interposed, regardless of the preliminary water heater. , It may be a configuration that can be connected for general purposes.

That is, as described above, in order to allow hot water from the hot water storage tank to flow into the hot water supply pipe between the secondary side of the hot water storage tank and the switching three-way valve, the preliminary water heater is provided via a flow path changing three-way valve. A flow path changing pipe that can be connected to the water heater may be connected to the water heater.

In addition, any of the configuration in which the switching three-way valve is interposed, the configuration in which the switching three-way valve is not interposed, and the general-purpose configuration may be configured by connecting a compatible spare water heater. Mainly, the configuration without connecting the spare water heater is for connecting to the existing spare water heater, while the system including the spare water heater as a component is for introducing a new hot water supply system. belongs to.

The drain drain pipe that discharges water such as dew condensation generated in the recirculation cycle of the heat pump from the heat pump is equipped with an outside air temperature sensing type heater that automatically operates when the outside air temperature falls below a predetermined temperature. You may.

The hot water storage type hot water supply system according to the present invention operates the preliminary water heater until a desired set temperature is reached when a problem such as running out of hot water occurs while making maximum use of the hot water generated and stored by the heat pump. Therefore, even in a cold region, it is possible to efficiently and effectively supply hot water at a desired temperature at all times.

FIG. 1 is a schematic configuration diagram of a hot water storage type hot water supply system according to the present invention, FIG. 1A is a diagram showing a flow of hot water supply when the spare water heater is stopped, and FIG. 1B is a diagram showing a flow of hot water supply when the spare water heater is operating. It is a figure which showed the flow of the hot water supply of. FIG. 2 is a schematic configuration diagram of a hot water storage type hot water supply system according to the first embodiment of the present invention. FIG. 3 is a schematic configuration diagram of a hot water storage type hot water supply system according to a second embodiment of the present invention. FIG. 4 is a schematic configuration diagram of a hot water storage type hot water supply system according to a third embodiment of the present invention. FIG. 5 is a schematic configuration diagram of a hot water storage type hot water supply system according to a fourth embodiment of the present invention. FIG. 6 is a schematic configuration diagram of a hot water storage type hot water supply system according to a fifth embodiment of the present invention. FIG. 7 is a schematic configuration diagram of a hot water storage type hot water supply system according to a sixth embodiment of the present invention.

FIG. 1 is a schematic configuration diagram of a hot water storage type hot water supply system according to the present invention. In the figure, the solid arrow indicates the flow of hot water supply, and the broken line arrow indicates the flow of water supply. Reference numeral 1 denotes a hot water generation unit of the hot water storage type hot water supply system according to the present invention. In the present embodiment, a heat pump will be used as the hot water generating unit, but the purpose is not limited to this. (The same shall apply hereinafter in each embodiment.)

The hot water generated by the heat pump 1 is stored in the hot water storage tank 2 (corresponding to the hot water storage section). The hot water stored in the hot water storage tank 2 is discharged in response to the request of the load 4. Here, the “load” refers to equipment (kitchen, wash basin, bath, etc.) equipped with a hot water tap used by consumers.

Since the amount of water corresponding to the amount of hot water consumed by discharging hot water from the hot water storage tank 2 is replenished to the hot water storage tank 2 from the water supply pipe 5, the hot water storage tank 2 is always in a full state. When water is replenished into the hot water storage tank 2 from the water supply unit 5 (arranged in parallel with the flow of the broken line arrow), hot water is generated by the heat pump 1 and the hot water is stored in the hot water storage tank 2 again.

The temperature of the hot water discharged from the hot water storage tank 2 is set by the control unit 3. Further, the control unit 3 detects the actual hot water temperature H of the hot water that is set to the set temperature P from the hot water storage tank 2 and discharges the hot water, and controls the hot water supply at the set temperature P in response to the hot water supply request from the load 4. To do.

When the load 4 uses an amount equal to or greater than the amount of hot water at the set temperature P stored in the hot water storage tank 2, the hot water satisfying the set temperature P is lost in the hot water storage tank 2, resulting in a so-called "out of hot water" state. In a hot water storage type hot water supply system, when the hot water runs out, hot water is generated by the heat pump 1, but in general, it takes several hours after the hot water runs out until hot water that can be supplied is generated. , The consumer side has no choice but to limit the use of hot water, which causes inconvenience that stable hot water supply becomes difficult. Therefore, a direct pressure type or combustion type preliminary water heater 6 is interposed between the hot water storage tank 2 and the load 4 so that hot water having a set temperature P can be continuously supplied even if the hot water storage tank 2 runs out of hot water. I'm letting you.

Here, the direct pressure type is provided with a heat exchange pipe, and when water flows through the pipe, the pipe is heated to generate hot water, and at the same time as the hot water tap is opened, the hot water is instantly heated and supplied. It has become. In addition, the water supply pressure and the hot water discharge pressure are almost the same. On the other hand, the combustion type refers to a type that uses gas, kerosene, or the like as a heat source for generating hot water. In any case, unlike the hot water storage type water heater, the spare water heater 6 has a feature that hot water at a temperature desired by a customer can be constantly and immediately supplied without running out of hot water. If so, there is no particular limitation.

As shown in FIG. 1A, when the hot water outlet temperature H is detected, if the hot water outlet temperature H is equal to or higher than the set temperature P, the hot water is discharged from the hot water storage tank 2 without operating the spare water heater 6. It is controlled so that the hot water is passed through and supplied to the load 4.

On the other hand, as shown in FIG. 1B, when the hot water outlet temperature H becomes lower than the set temperature P, the hot water discharged from the hot water storage tank 2 is set to the set temperature by the preliminary water heater 6 whose operation is controlled by the control unit 3. After being heated to P, hot water is supplied to the load 4.

As described above, the hot water storage type hot water supply system according to the present invention uses the hot water of the hot water storage tank 2 until the hot water storage tank 2 runs out of hot water, and operates the spare water heater 6 only when the hot water runs out. Here, since the preliminary water heater 6 heats not the water supplied from the water supply pipe but the hot water after the hot water runs out, the time for reaching the set temperature P can be shortened. As a result, the hot water generated by using the cheap nighttime charge is used to the maximum extent, and only when the hot water runs out, the reserve water heater 6 is used to add the desired temperature at which the hot water is insufficient after the hot water runs out. Since it is heated, energy efficiency is increased, and hot water at a desired temperature can be always provided while keeping costs down.

Hereinafter, specific embodiments of the present invention will be described with reference to FIGS. 2 to 7.

<First Embodiment>
As shown in FIG. 2, the system described in the present embodiment is a hot water supply system dedicated to the load equipment 41 (specifically, the kitchen, the wash basin, etc.) excluding the so-called bath kettle as the load 4. The load equipment 41 is composed of a plurality of load equipments such as 41a, 41b and 41c.

The heat pump 1 includes a fan 11 and is installed outdoors in order to take in outside air. In the present embodiment, the heat pump 1 side is referred to as the primary side and the load 4 side is referred to as the secondary side with respect to the hot water storage tank 2 (hereinafter, the same applies to each embodiment).

From the heat energy of the outside air taken in by the fan 11, the refrigerant is warmed through the heat exchanger 12 and compressed by the compressor 13. By being compressed, the refrigerant becomes hotter than when the heat energy is taken in by the heat exchanger 12. The high-temperature refrigerant is sent to the water heat exchanger 15 via the refrigerant flow path 14, and the heat energy is transferred to the water on the hot water storage tank 2 side in the heating region E.

The refrigerant after the transition is expanded by the expansion valve 16 to a low temperature, and is sent to the heat exchanger 12. By repeating the reflux cycle from the fan 11 to the expansion valve 16, hot water is constantly supplied to the hot water storage tank 2, and stable hot water supply becomes possible.

The hot water storage tank 2 receives the heat energy transfer in the heating region E of the heat pump 1 and the tank main body 21, and supplies the generated hot water to the tank main body 21 and from the supply pipe 22 to the tank main body 21. The supply port 23 for supplying the hot water, the hot water outlet 24 for supplying the hot water stored in the tank body 21 to the load 4 on the secondary side, the hot water supply pipe 25 for supplying the hot water discharged from the hot water outlet 24, and the tank. It is composed of a water supply port 26 for replenishing water corresponding to the amount of hot water consumed by the hot water from the main body 21 and a water supply port 27 for supplying the supplied water to the supply pipe 22.

As described above, the hot water supplied from the supply port 23 and the water supplied from the water supply port 26 flow into the same tank body 21, but due to the difference in specific gravity, the lower part is the low temperature layer W and the upper part is the high temperature layer H. Therefore, a middle temperature layer M in the intermediate temperature zone between the low temperature layer W and the high temperature layer H is formed, and the three parties do not mix and maintain the layer structure. Therefore, it is preferable that the tank body 21 is made of, for example, a vertically long cylindrical shape, and has a supply port 23 and a hot water outlet 24 at the upper part and a water supply port 26 and a water supply port 27 at the lower part.

The hot water on the high temperature layer H side flows into the spare water heater 6 connected to the hot water supply pipe 25 from the hot water outlet 24. On the other hand, the water on the low temperature layer W side flows into the hot water storage tank main body 21 from the hot water storage tank side water supply pipe 51 of the water supply unit 5 through the water supply port 26.

The spare water heater 6 is composed of a water heater main body 61 and a spare hot water outlet pipe 62, and the inflowing hot water is passed through a pipe (not shown) arranged in the water heater main body 61. Outflow from 62.

The hot water from the spare hot water supply pipe 62 merges with the load side water supply pipe 52 of the water supply unit 5 and is supplied to the load 4. A mixing tap is attached to the terminals of the loads 41a to 41c (not shown), and hot water is supplied at a temperature desired by the consumer.

As described with reference to FIG. 1, the standby water heater 6 is controlled by the control unit 3 to operate when the temperature of the hot water discharged from the hot water storage tank 2 is lower than the preset set temperature. Has been done. In addition to controlling the operation of the preliminary water heater 6, the control unit 3 executes the setting of the hot water supply temperature, the calculation of the amount of hot water in the hot water storage tank 2, and the like.

The control unit 3 is composed of at least an arithmetic processing unit 31, a temperature sensor 32 that detects the hot water discharge temperature of the hot water storage tank 2, and temperature setting units 33 and 34. The arithmetic processing unit 31 is composed of, for example, an embedded program for performing the various controls and arithmetic executions, a memory, a ROM, a RAM, and the like. The memory stores the setting information input from the temperature setting unit 33, which will be described later. Further, the ROM stores various operation programs, and the RAM temporarily stores various data generated in the process of the arithmetic processing. The temperature setting units 33 and 34 have an input unit such as a liquid crystal display, and in addition to the temperature setting, display the status in the hot water storage tank 2 (the temperature setting unit is a hot water discharge from the hot water storage tank 2 and a preliminary water heater. Since there are two hot waters that are discharged from No. 6, two are installed side by side, but they may be integrated into one. Further, although the arithmetic processing unit 31 is one in the drawing, the above temperature Two things may be installed side by side corresponding to the setting unit). Although the temperature sensor 32 is shown as a single body separated from the tank main body 21 in the drawing for convenience, in reality, the temperatures of the low temperature layer W, the medium temperature layer M, and the high temperature layer H are described above. Is preferably detected and output to the arithmetic processing unit 31. More specifically, a known thermistor may be used for the temperature sensor 32.

In the temperature setting unit 33, the set temperature of the hot water discharged from the hot water storage tank 2 is set as the first set temperature, and the set temperature of the hot water discharged from the spare hot water pipe 62 is set as the second set temperature lower than the first set temperature. When the temperature detected by the sensor 32 becomes lower than the second set temperature, the control unit 3 operates the preliminary water heater 6 to heat the temperature to the second set temperature and supply hot water to the load. For example, if the first set temperature is set to 50 degrees and the second set temperature is set to 45 degrees, the spare water heater 6 will not operate if the temperature of the hot water discharged from the hot water storage tank 2 is 45 degrees or higher. , The hot water is supplied to the load 4 without being heated. On the other hand, when the temperature of the hot water discharged from the hot water storage tank 2 is detected at 40 degrees, the control unit 3 operates the preliminary water heater 6 to heat the hot water discharged from the hot water storage tank 2 by a difference of 5 degrees. Then, the hot water is discharged at 45 degrees.

While the preliminary water heater 6 is operating, the heat pump 1 operates to generate hot water, and hot water that has reached the first set temperature (50 degrees in the above example) can be discharged to the hot water storage tank 2. When the temperature sensor 32 detects that the water has been stored, the operation of the preliminary water heater 6 is stopped, and when there is a request for hot water from the load 4 side, the hot water discharged from the hot water storage tank 2 is added to the preliminary water heater 6 again. You may try to supply hot water without warmth.

If the operating condition of the preliminary water heater 6 is lower than the first set temperature, the preliminary water heater 6 must be operated frequently, which leads to a decrease in energy efficiency. In particular, if the hot water in the hot water storage tank 2 is stopped each time the temperature of the hot water in the hot water storage tank 2 becomes equal to or higher than the first set temperature after the operation of the preliminary water heater 6, the operation and stop are repeated with high frequency, and the preliminary hot water supply is performed. Unburned gas stays in the vessel 6 and causes malfunction such as abnormal ignition. Therefore, a predetermined temperature difference is provided between the temperature of the hot water discharged from the hot water storage tank, that is, the first set temperature, and the temperature at which the preliminary water heater operates, that is, the second set temperature.

In the case of cold regions, the temperature inside the hot water storage tank 2 tends to decrease faster in winter due to the influence of the outside air, and the amount of hot water used tends to increase. Therefore, by operating the preliminary water heater 6 at the minimum necessary by setting the temperature as described above, hot water can be stably supplied at a desired temperature, and hot water in the hot water storage tank 2 is used to the maximum extent. The cost required for generation can be suppressed.

The spare water heater 6 may be provided in a connected form when the hot water storage type hot water supply system according to the present invention is installed, or may be connected to an existing one. Hereinafter, also in each embodiment, a spare water heater 6 is incorporated in advance as a component of the system, and an existing spare water heater 6 can be connected (that is, a spare water heater 6 is not included as a component). Two forms can be provided.

By the way, as described above, since the heat pump 1 is installed outdoors, it is usually installed on the gantry 17. Then, in the reflux cycle of the heat pump 1, dew condensation occurs due to the temperature difference. Therefore, in order to discharge this, a drain drain pipe (not shown) is usually connected, but in a cold region, in order to prevent the drain drain pipe from freezing in winter and making it impossible to discharge the dew condensation. In general, installers do not connect drain drains. However, if the drain drain pipe is not connected, drainage will occur in the vicinity of the gantry 17, which will cause installation instability due to corrosion and further malfunction. Since temperature detection is one of the important points in the hot water storage type hot water supply system according to the present invention, it is important to eliminate the cause of the malfunction of the heat pump 1, particularly the malfunction in winter in a cold region. Therefore, after connecting the drain drain pipe, an outside air temperature sensing type heater (not shown) that automatically operates when the outside air temperature falls below a predetermined temperature may be attached. Even in winter in cold regions, the outside air temperature may be the temperature at which the drain drain pipe does not freeze. Therefore, by adopting the outside air temperature sensing type, a power saving effect can be expected as compared with the heater that is always energized in winter (hereinafter, similarly, in each embodiment, the drain drain pipe is connected and the outside air temperature sensing type heater is installed. It is possible).

<Second Embodiment>
FIG. 3 shows a form when the load 4 includes the bath 42. Hereinafter, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted unless otherwise specified.

In the present embodiment, the preliminary water heater 6 has a function of reheating the bath 42. That is, the hot water of the bath 42 whose temperature has dropped is sent to the preliminary water dispenser main body 61 via the feed pipe 63 by a suction pump (not shown). The hot water sent in is heated by the preliminary water heater 6 and then supplied to the bath 42 via the return pipe 64.

On the other hand, the hot water filling and the additional hot water of the bath are supplied from the hot water supply pipe 25 connected to the hot water storage tank 2 via the hot water supply pipe 28 for the bath which is branched and connected. Therefore, even if the hot water storage tank 2 is lower than the first set temperature, the hot water filling and the additional hot water of the bath are supplied by the hot water supply pipe 28 for the bath, and only the insufficient temperature is re-cooked by the preliminary water heater 6. It is heated. Even if the temperature is lower than the second set temperature, it is better to use the hot water in the hot water storage tank and re-cook with the spare water heater 6, so that the hot water supply including the hot water filling and the additional hot water is replaced with the spare water heater 6. This is because the overall thermal efficiency is better than that.

<Third Embodiment>
In FIG. 4, a switching three-way valve 7 is provided between the hot water supply pipe 25 and the load 4, and the switching three-way valve 7 and the spare water heater 6 are connected by a switching hot water outlet pipe 66.

When the existing reserve water heater 6 is used, the allowable inflow pressure of the reserve water heater 6 may be lower than the outlet pressure of the hot water storage tank 2. For example, when the hot water outlet pressure of the hot water storage tank 2 exceeds 180 kPa and the allowable inflow pressure of the preliminary water heater 6 is 80 kPa, when hot water flows from the hot water storage tank 2 into the spare water heater 6, the can body in the spare water heater 6 Since the piping and the like are exposed to excessive pressure, there is a risk of damage, which may cause water leakage. In recent years, while there is a hot water storage type hot water supply system having a hot water discharge pressure close to the tap pressure, a so-called semi-hot water storage type oil water heater (this type of water heater is equipped with a combustion system and conforms to the definition of the preliminary water heater. The permissible inflow pressure is 190 kPa at the highest, and the water heater decompression type is adopted. Therefore, in the case of the above combination, that is, the configuration in which the hot water storage type hot water supply system having a high hot water discharge pressure and the semi-hot water storage type oil water heater are connected, there is a risk of damaging the equipment on the semi-hot water storage type oil water heater side.

Therefore, when the temperature of the hot water discharged from the hot water storage tank 2 is equal to or higher than the first set temperature, the control unit 3 releases the flow of the switching three-way valve 7 in the 7a to 7c directions and shuts off the flow from 7a to 7b. By controlling the opening and closing in this way, the hot water discharged from the hot water storage tank 2 is supplied to the load 4 as it is.

On the other hand, when the temperature of the hot water discharged from the hot water storage tank 2 is lower than the second set temperature, the control unit 3 blocks the flow of the switching three-way valve 7 in the direction from 7a to 7c and opens the flow from 7b to 7c. By controlling the opening and closing in this way, the hot water discharged from the hot water storage tank 2 is prevented from flowing into the preliminary water heater 6, and the hot water is supplied from the preliminary water heater 6 to the load 4 via the switching hot water pipe 66.

When hot water is supplied from the reserve water heater 6, water needs to be supplied to the reserve water heater 6, so that water may be supplied from the reserve hot water supply side water supply pipe 65 branched from the hot water storage tank side water supply pipe 51.

Further, when the detection unit 32 detects the first set temperature or higher after the preliminary water heater 6 is operated, the control unit 3 stops the operation of the preliminary water heater 6 again and switches 7a to 7c of the switching three-way valve 7. At the same time as opening, the flow of the switching three-way valve 7 from 7a to 7b is cut off, and the hot water of the hot water storage tank 2 is supplied to the load 4 as it is from the hot water supply pipe 25.

The control unit 3 may automatically execute each of the opening / closing controls of the switching three-way valve 7 based on the temperature detected by the temperature sensor 32. In the present embodiment, the switching three-way valve 7 is an electromagnetic three-way valve so as to be compatible with the automatic opening / closing control. The control unit 31 (specifically, the displays of the temperature setting units 33 and 34) displays the temperature detected by the temperature sensor 32 and displays a message prompting the opening / closing control of the switching three-way valve 7 (message). In addition to the character notation, it may be written by voice.) Alternatively, the consumer may manually open and close the three-way valve 7.

<Embodiment 4>
FIG. 5 shows that when the load 4 includes at least the bath 42, the reserve water heater 6 has a function of additional cooking with respect to the bath 42, and the control unit 3 operates the reserve water heater 6, the control unit 3 Indicates a form in which the preliminary water heater 6 is used for additional cooking. The difference from the fifth embodiment, which will be described later, is that the hot water supply from the hot water storage tank 2 is not completely cut off when the preliminary water heater 6 is operated to re-cook.

<Embodiment 5>
FIG. 6 shows a mode in which when the control unit 3 operates the preliminary water heater 6, the control unit 3 controls the flow path so that the hot water filling and the additional hot water of the bath 42 are supplied from the hot water storage tank 2. .. This embodiment is a modification of the second embodiment that can be applied when the allowable inflow pressure of the preliminary water heater 6 is lower than the outflow pressure of the hot water storage tank 2 as in the third embodiment.

<Embodiment 6>
FIG. 7 shows a versatile embodiment applicable to both the second and fifth embodiments.

That is, in order to allow hot water from the hot water storage tank 2 to flow into the hot water supply pipe 25 between the secondary side of the hot water storage tank 2 and the switching three-way valve 7, the spare water heater 6 is supplied via the flow path changing three-way valve 8. A connectable flow path changing pipe 67 is connected.

When the allowable inflow pressure of the preliminary water heater 6 is equal to or higher than the outflow pressure of the hot water storage tank 2 as in the second embodiment, the control unit 3 releases the flow from 8a to 8b of the flow path changing three-way valve 8. At the same time, the flow of the branch three-way valve 7 from 7a to 7c is blocked. In this case, the configuration is the same as that of the second embodiment.

On the other hand, when the allowable inflow pressure of the preliminary water heater 6 is lower than the outflow pressure of the hot water storage tank 2 as in the fifth embodiment, the control unit 3 blocks the flow of the flow path changing three-way valve 8 from 8a to 8b. At the same time, the flow from 7a to 7c of the branch three-way valve 7 is opened. In this case, the configuration is the same as that of the fifth embodiment.

In this embodiment, for example, when the spare water heater 6 is replaced due to a failure or the like, the piping configuration is not changed depending on the height relationship between the allowable inflow pressure and the hot water discharge pressure of the hot water storage tank 2. It shows a versatile product that can be replaced and installed.

1 Heat pump 11 Fan 12 Heat exchanger 13 Compressor 14 Refrigerant flow path 15 Water heat exchanger 16 Expansion valve 17 Stand 2 Hot water storage tank 21 Hot water storage tank body 22 Supply pipe 23 Supply port 24 Hot water outlet 25 Hot water supply pipe 26 Water supply port 27 Water supply port 3 Control unit 31 Calculation processing unit 32 Temperature sensor 33, 34 Temperature setting unit 4 Load 41 Load equipment 42 Bath 5 Water supply unit 51 Hot water storage tank side water supply pipe 52 Load side water supply pipe 6 Spare water heater 61 Spare water heater body 62 Spare system hot water supply pipe 63 Feed pipe 64 Return pipe 65 Spare hot water supply side Water supply pipe 66 Switching hot water supply pipe 67 Flow path changing pipe 7 Switching three-way valve 8 Flow flow changing three-way valve

Claims (12)

It is a hot water storage type hot water supply system that stores the generated hot water and then supplies it.
It consists of a heat pump that compresses the refrigerant that has absorbed the heat energy of the outside air and recirculates it through a heat exchanger, and has a hot water generator that generates hot water from the supplied water.
The primary side is connected to a hot water supply pipe generated by the heat exchanger, and the secondary side is composed of a hot water storage tank connected to a hot water supply pipe that sends the hot water to a plurality of loads.
A hot water storage unit that stores the generated hot water and discharges the hot water to the load via a hot water supply pipe.
A spare hot water supply pipe that allows at least a direct pressure type or combustion type spare water heater to be connected between the hot water supply pipe and the load.
A detection unit that detects the temperature of hot water in the hot water storage unit,
A control unit that can set the temperature of the hot water discharged from the hot water storage tank as the first set temperature and the temperature of the hot water discharged from the preliminary hot water pipe as the second set temperature lower than the first set temperature. Have,
When the temperature detected by the detection unit is a temperature from the first set temperature to the second set temperature, the control unit does not operate the spare water heater, but the spare water heater and the spare hot water pipe. The temperature detected by the detector when hot water is supplied to the load via
When the temperature is lower than the second set temperature, the control unit operates the preliminary water heater to heat the water heater to the second set temperature so that hot water can be supplied to the load, and dew condensation and the like generated in the recirculation cycle of the heat pump. A hot water storage type hot water supply system in which an outside air temperature sensing heater that automatically operates when the outside air temperature falls below a specified temperature is attached to a drain drain pipe that drains the water from the heat pump. The hot water storage type hot water supply system according to claim 1, wherein the control unit stops the operation of the preliminary water heater when the detection unit detects a temperature equal to or higher than the first set temperature after the operation of the preliminary water heater. When the load includes at least a bath, the preliminary water heater has a function of additional cooking with respect to the bath, and the control unit operates the preliminary water heater, the control unit is the bath. The hot water storage type hot water supply system according to claim 1 or 2, wherein hot water filling and additional hot water are supplied from the hot water storage tank and re-cooked by the preliminary water heater. The hot water storage type hot water supply system according to any one of claims 1 to 3, wherein the spare water heater is connected to the spare hot water supply pipe. It is a hot water storage type hot water supply system that stores the generated hot water and then supplies it.
It consists of a heat pump that compresses the refrigerant that has absorbed the heat energy of the outside air and returns it through a heat exchanger, and has a hot water generator that generates hot water from the supplied water.
The primary side is connected to a hot water supply pipe generated by the heat exchanger, and the secondary side is composed of a hot water storage tank connected to a hot water supply pipe that sends the hot water to a plurality of loads, and stores the generated hot water. Then, the hot water storage unit that discharges the hot water to the load via the hot water supply pipe,
A switching three-way valve provided between the hot water supply pipe and the load,
A switching hot water pipe that enables connection to a direct pressure type or combustion type preliminary water heater whose inflow allowable pressure of water or hot water is lower than the hot water discharge pressure of the hot water storage tank.
A flow path changing three-way valve interposed in the hot water supply pipe between the secondary side of the hot water storage tank and the switching three-way valve to allow hot water from the hot water storage tank to flow in.
One is connected to the flow path changing three-way valve, and the other is connected to the spare water heater.
A detector that detects the temperature of hot water in the hot water storage tank,
A control unit that can set the temperature of the hot water discharged from the hot water storage tank as the first set temperature and the temperature of the hot water discharged from the preliminary hot water pipe as the second set temperature lower than the first set temperature. Have,
The control unit controls the opening and closing of the flow path changing three-way valve, and when the allowable inflow pressure of the preliminary water heater is lower than the hot water discharge pressure of the hot water storage tank, the flow path changing pipe side is shut off and the hot water supply pipe is cut off. When the side is opened and the allowable inflow pressure is equal to or higher than the outflow pressure of the hot water storage tank, the flow path changing pipe side is opened and the hot water supply connecting the flow path changing three-way valve and the switching three-way valve is connected. The pipe side is shut off, the temperature of the hot water discharged from the hot water storage tank is set as the first set temperature, and the temperature of the hot water discharged from the switching hot water pipe can be set as the second set temperature lower than the first set temperature. A hot water storage type hot water supply system that operates the preliminary water heater to heat up to the second set temperature and supply hot water to the load when the temperature detected by the detection unit is lower than the second set temperature. When the detection unit detects the set temperature or higher after the preliminary water heater is operated, the control unit stops the operation of the preliminary water heater, controls the opening and closing of the switching three-way valve, and shuts off the switching hot water pipe. The hot water storage type hot water supply system according to claim 5, wherein the hot water supply pipe is opened so that hot water in a hot water storage tank can be supplied to a load. The hot water storage type hot water supply system according to claim 5 or 6, wherein the control unit automatically executes opening / closing control of the switching three-way valve based on the temperature detected by the detection unit. When the load includes at least a bath, the preliminary water heater has a function of additional cooking with respect to the bath, and the control unit operates the preliminary water heater, the control unit operates the preliminary water heater. The hot water storage type hot water supply system according to any one of claims 5 to 7, wherein the hot water is re-cooked. The hot water storage type hot water supply system according to claim 8, wherein when the control unit operates a preliminary water heater, the control unit supplies hot water from the hot water storage tank to the hot water filling and adding hot water of the bath. The hot water storage type hot water supply system according to any one of claims 5 to 9, wherein the preliminary water heater is connected to the switching hot water supply pipe. The hot water storage type hot water supply system according to any one of claims 5 to 10 , wherein the preliminary water heater is connected to the switching hot water supply pipe. 5. Claim 5 in which an outside air temperature sensing type heater that automatically operates when the outside air temperature falls below a predetermined temperature is attached to a drain drain pipe that discharges water such as dew condensation generated in the recirculation cycle of the heat pump from the heat pump. The hot water storage type hot water supply system according to any one of claims 11 to 11 .

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