JP2016180565A - Hot water storage type water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deposition of scale on a secondary side of a heat exchanger for hot water supply and to preferably maintain heat conduction efficiency and a hot water supply flow rate of the heat exchanger for hot water supply for a long period of time.SOLUTION: A heat pump type water heater includes: a heat pump unit 1; a hot water storage tank 8; a control unit 9; an outgoing pipeline 11 for water heating; a return pipeline 12 for water heating; a flow passage switching valve 13; a heat exchanger 16 for hot water supply; and a remote controller 40 and the like. The control unit 9 can execute both a heating utilization hot water supply operation for heating water by the heat exchanger 16 for hot water supply with heating hot water from the heat pump unit 1 as a heat source, and a stored hot water utilization hot water supply operation for heating water by the heat exchanger 16 for hot water supply with stored hot water from the hot water storage tank 8 as the heat source. Also, the control unit 9, by controlling the flow passage switching valve 13 when performing hot water supply, switches which hot water is introduced to a primary side flow passage of the heat exchanger 16 for hot water supply out of the heating hot water and the stored hot water, based on a target hot water supply temperature.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hot water storage type water heater that can also use high hardness water.

  As a prior art, for example, a heat pump type water heater as described in Patent Document 1 is known. The conventional water heater has a function of using high-temperature water stored in a tank as a heat source. More specifically, when hot water is supplied, heat is exchanged between high-temperature water introduced from the tank to the primary side of the heat exchanger and hot water for hot water supply such as tap water and well water introduced to the secondary side of the heat exchanger. The hot water for hot water supply is heated and supplied to the outside.

JP 2012-7802 A

  In the prior art described above, high-hardness water containing a relatively high concentration of hardness components such as calcium may be used as hot water for hot water supply. However, when high-hardness water is heated in the heat exchanger of the water heater, the hardness component in the water is deposited as a scale (solid precipitate) such as calcium carbonate, thereby improving the heat conduction efficiency of the heat exchanger. There is a problem that the temperature is lowered or the scale is clogged in the heat exchanger and the hot water flow rate is lowered.

  The present invention has been made in order to solve the above-described problems, and suppresses the scale from adhering to the secondary side of the hot water heat exchanger, and the heat conduction efficiency and hot water flow rate of the hot water heat exchanger. It aims at providing the hot water storage type water heater which can maintain well for a long period of time.

  The hot water storage type hot water supply apparatus according to the present invention includes a heating source for heating hot water, a hot water storage tank for storing hot water heated by the heating source, a primary flow path and heating for introducing hot water from the heating source and the hot water storage tank. A hot water supply heat exchanger that has a secondary flow path into which the target water is introduced and heats the heated target water by performing heat exchange between the primary flow path and the secondary flow path; Introduced into the primary flow path of the hot water supply heat exchanger and target temperature setting means for setting the target temperature of hot water hot water flowing out from the secondary flow path of the hot water supply heat exchanger toward the hot water supply target as the target hot water supply temperature By switching the hot water to be heated to either one of heated hot water heated by a heating source and hot water stored in a hot water storage tank, and controlling the switching means when hot water is supplied, Either hot water or hot water storage hot water is used as the primary side of the heat exchanger for hot water supply It comprises a control unit for switching on the basis whether to introduce the road to the target hot-water supply temperature, the.

  ADVANTAGE OF THE INVENTION According to this invention, even when high hardness water is used as heating object water, it can suppress that a scale adheres and deposits on the heat exchanger for hot water supply. Therefore, the heat conduction efficiency and the hot water flow rate of the hot water heat exchanger can be maintained well over a long period of time, and the life of the hot water storage type hot water heater can be extended.

It is a block diagram which shows the heat pump type water heater by Embodiment 1 of this invention. In Embodiment 1 of this invention, it is operation | movement explanatory drawing which shows a hot water storage driving | operation. In Embodiment 1 of this invention, it is operation | movement explanatory drawing which shows the hot water storage utilization hot water supply driving | operation. In Embodiment 1 of this invention, it is operation | movement explanatory drawing which shows a heating utilization hot water supply driving | operation. It is a block diagram which shows the heat pump type water heater by Embodiment 2 of this invention. In Embodiment 2 of this invention, it is a characteristic diagram which shows the pulsation control of the hot water supply flow volume. It is a block diagram which shows the heat pump type water heater by Embodiment 3 of this invention. In Embodiment 3 of this invention, it is a characteristic diagram which illustrates the relationship between pH and calcium hardness of hot water, and the precipitation tendency of a scale.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used in this specification, common elements are denoted by the same reference numerals, and redundant description is omitted. Further, the present invention is not limited to the following embodiments, and can be variously modified without departing from the gist of the present invention. Further, the present invention includes all combinations of configurations that can be combined among the configurations shown in the following embodiments. Moreover, in embodiment, the heat pump type water heater is described as an example of the hot water storage type water heater.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing a heat pump type hot water heater according to Embodiment 1 of the present invention. As shown in this figure, the heat pump type water heater of the present embodiment includes a heat pump unit 1 arranged outside the room and a tank unit 2 arranged inside the room. The heat pump unit 1 is a heating source for heating (boiling) hot water supplied from a hot water storage tank 8 and a water source, which will be described later, and the compressor 3, the water heating heat exchanger 4, the expansion valve 5 and the evaporator 6 are used as refrigerant. A heat pump cycle connected in a ring shape by a pipe 7 is provided. For example, carbon dioxide, which is a natural refrigerant, is used as the refrigerant circulating through the refrigerant pipe 7. In this specification, warm water (hot water) and water may be collectively referred to as “hot water”. Moreover, in this specification, the hot water heated by the heat pump unit 1 is referred to as “heating hot water”, the hot water stored in the hot water storage tank 8 is referred to as “hot water hot water”, and a hot water supply heat exchanger 16 described later is used. The hot water flowing out from the secondary channel toward the hot water supply target may be referred to as “hot water hot water”.

  The tank unit 2 includes a hot water storage tank 8, a control unit 9, a water pump 10, a water heating forward pipe 11, a water heating return pipe 12, a flow switching valve 13, a hot water heating forward pipe 14, and a hot water heating return pipe. 15, a hot water supply heat exchanger 16, a relief valve 17, a water intake valve 18, a water introduction valve 19, a water supply pipe 20, a hot water supply pipe 22, and the like are incorporated. The hot water storage tank 8 stores hot water heated by the heat pump unit 1. A hot water inlet / outlet 8 a is provided in the upper part of the hot water storage tank 8, and a water inlet 8 b and a water outlet 8 c are provided in the lower part of the hot water tank 8. Heated hot water is introduced into the hot water storage tank 8 from the upper hot water inlet / outlet 8a, and cold water such as tap water and well water is introduced from the lower water inlet 8b. As a result, a temperature stratification is formed in the hot water storage tank 8 so that the water temperature increases toward the upper side. Further, a relief valve 17 is connected to the upper part of the hot water storage tank 8 to release the pressure when the pressure in the tank becomes excessive.

  One end of the water heating forward pipe 11 is connected to the secondary inlet of the water heating heat exchanger 4, and the other end is connected to a water outlet 8c of the hot water storage tank 8 via a water intake pipe 15a described later. Yes. A water introduction valve 19, a water feed pump 10, and a water intake valve 18 are provided in the middle of the water heating forward pipe 11 in order from the side closer to the water heating heat exchanger 4. Further, the water introduction port 8b of the hot water storage tank 8 and the water introduction valve 19 are connected to each other via a tank return pipe 11a. The water supply pump 10 is a pump for circulating hot water in a hot water storage circuit, a hot water storage hot water circulation circuit, and a heating hot water circulation circuit described later. On the other hand, one end of the water heating return pipe 12 is connected to the secondary outlet of the water heating heat exchanger 4, and the other end is connected to the hot water inlet / outlet 8a of the hot water storage tank 8 via the tank upper pipe 12a. Yes. A flow path switching valve 13 is provided between the water heating return pipe 12 and the tank upper pipe 12a.

  The flow path switching valve 13 is configured by an electromagnetic three-way valve having three ports. A water heating return pipe 12, a tank upper pipe 12a, and a hot water heating forward pipe 14 are connected to each port of the flow path switching valve 13, respectively. The flow path switching valve 13 is connected to the first flow path form for communicating the water heating return pipe 12 and the tank upper pipe 12a, and the second flow path for communicating the tank upper pipe 12a and the hot water supply heating forward pipe 14. The flow path is switched to any one of three flow path forms including a flow path form and a third flow path form that communicates the water heating return pipe 12 and the hot water heating forward pipe 14. The hot water supply heating forward pipe 14 connects the flow path switching valve 13 and the primary side inlet of the hot water supply heat exchanger 16. The hot water heating return pipe 15 connects the primary outlet of the hot water heat exchanger 16 and the intake valve 18. The intake valve 18 and the water outlet 8c of the hot water storage tank 8 are connected to each other via an intake pipe 15a.

  The hot water supply heat exchanger 16 includes a primary side flow path through which hot water is introduced from the heat pump unit 1 and the hot water storage tank 8, and a secondary side flow path through which low temperature water to be heated is introduced from the water supply pipe 20. Have. The hot water supply heat exchanger 16 heats the heating target water using the heated hot water and the hot water storage hot water as a heat source by exchanging heat between the primary side flow path and the secondary side flow path. Is to be generated. The water supply pipe 20 supplies low-temperature water to the tank unit 2 from an external water source (not shown), and one end side is connected to the water source. The other end of the water supply pipe 20 branches inside the tank unit 2 and is connected to the secondary inlet and the water introduction valve 19 of the hot water supply heat exchanger 16. A pressure reducing valve 21 that adjusts the pressure of the low-temperature water introduced into the hot water storage tank 8 is provided in the middle of the water supply pipe 20. On the other hand, a hot water supply pipe 22 is connected to the secondary outlet of the hot water supply heat exchanger 16. The hot water supply pipe 22 supplies hot water supply hot water heated by the hot water supply heat exchanger 16 to an external hot water supply target (not shown). Examples of hot water supply objects include hot water taps such as showers and currants, bathtubs, hot water heaters, and the like.

  The intake valve 18 is constituted by an electromagnetic three-way valve having three ports. To each port of the water intake valve 18, a water heating forward pipe 11, a hot water supply heating return pipe 15 and a water intake pipe 15 a are respectively connected. The intake valve 18 has a first flow path configuration that communicates the water heating forward pipe 11 and the hot water supply heating return pipe 15, and a second flow path that communicates the water heating forward pipe 11 and the intake pipe 15 a. It is switched to one of two flow path forms consisting of a path form. The water introduction valve 19 is configured by an electromagnetic four-way valve having four ports. Each port of the water introduction valve 19 includes one end side of the water heating forward pipe 11 (on the heat pump unit 1 side), the other end side of the water heating forward pipe 11 (on the side of the hot water supply heat exchanger 16), and a tank return pipe 11a. And a water supply pipe 20 are connected to each other. And the water introduction valve 19 connects the 1st flow path form which connects the one end side of the water heating forward piping 11, and the other end side, the other end side of the water heating forward piping 11, and the tank return piping 11a. One of the three flow path forms consisting of a second flow path form that communicates and a third flow path form that communicates the water supply pipe 20 and the tank return pipe 11a (used when water is supplied to the hot water storage tank 8). Switched.

  The heat pump hot water heater forms a hot water storage circuit, a hot water hot water circulation circuit, and a heated hot water circulation circuit, which will be described later, according to the combination of the flow path forms of the flow path switching valve 13, the intake valve 18 and the water introduction valve 19 described above. . When hot water is supplied, hot water introduced into the primary flow path of the hot water supply heat exchanger 16 is changed to either heated hot water or hot water storage hot water depending on whether the hot water storage hot water circulation circuit or the heating hot water circulation circuit is selected. Switch. Therefore, the flow path switching valve 13, the intake valve 18 and the water introduction valve 19 constitute a specific example of the switching means in the present embodiment.

  Next, a control system of the heat pump type hot water heater will be described. The heat pump type water heater of the present embodiment includes a control unit 9 built in the tank unit 2 and a remote controller 40. The control unit 9 controls the heat pump type hot water heater, and is constituted by a microcomputer or the like, a storage circuit in which a control program or the like is stored in advance, and an arithmetic processing unit (CPU) that performs an operation based on the control program. And an input / output port for inputting and outputting signals. The input / output port includes a sensor system including various sensors mounted on a heat pump type hot water heater, and various types including a compressor 3, a water supply pump 10, a flow path switching valve 13, a water intake valve 18, a water introduction valve 19, and the like. The actuator is connected. The sensor system includes a tank temperature sensor 30, a tapping temperature sensor 31, a hot water supply flow rate sensor 32, and the like.

  A plurality of tank temperature sensors 30 are mounted at different height positions on the surface of the hot water storage tank 8. The controller 9 can detect the temperature distribution in the hot water storage tank 8 based on the detection result of the tank temperature sensor 30 and can calculate the amount of hot water stored in the hot water storage tank 8 (hot water storage amount). The hot water temperature sensor 31 detects the temperature of hot water (heating hot water) flowing out from the water heating heat exchanger 4 of the heat pump unit 1. The hot water supply flow rate sensor 32 detects the flow rate of hot water flowing through the secondary flow path of the hot water supply heat exchanger 16, that is, the amount of hot water supply hot water. The remote controller 40 is installed in, for example, a kitchen or bathroom, and is operated by a user, and is connected to the control unit 9 so as to be able to communicate with each other.

  The remote controller 40 inputs an operation command for the heat pump type hot water heater or changes various setting values, and includes an operation unit operated by a user and a display unit for displaying various information. The set value that can be changed by the remote controller 40 includes a target hot water temperature that is a target temperature of hot water and hot water flowing out from the secondary side flow path of the hot water supply heat exchanger 16 toward the hot water supply target. That is, the remote controller 40 corresponds to the target temperature setting means of the present embodiment. The control unit 9 controls the heat pump type hot water heater by driving the actuator based on input information from the sensor system and the remote controller 40, and executes hot water storage operation, hot water storage hot water supply operation, heating hot water supply operation, and heat source switching control. To do. Hereinafter, these operations and controls will be described.

(Hot water storage operation)
FIG. 2 is an operation explanatory view showing a hot water storage operation in Embodiment 1 of the present invention. As shown in this figure, in the hot water storage operation, heated hot water heated by the heat pump unit 1 is stored in the hot water storage tank 8. During the hot water storage operation, the flow path switching valve 13 is switched to the first flow path configuration, the intake valve 18 is switched to the second flow path configuration, and the water introduction valve 19 is switched to the first flow path configuration. Thereby, a hot water storage circuit shown in FIG. 2 is formed between the heat pump unit 1 and the hot water storage tank 8. The hot water storage circuit passes through the water outlet 8c of the hot water storage tank 8 through the water intake pipe 15a, the water intake valve 18, the water pump 10, the water introduction valve 19 and the water heating forward pipe 11 in order of the water heating heat exchanger 4 2. After reaching the secondary flow path and passing through the secondary flow path, the water heating return pipe 12, the flow switching valve 13, and the tank upper pipe 12a are sequentially passed to the hot water inlet / outlet 8a of the hot water storage tank 8. It is a circulation channel that reaches.

  In the hot water storage operation, the heat pump unit 1 and the water pump 10 are operated with the hot water storage circuit formed as described above. As a result, the low-temperature water staying in the lower part of the hot water storage tank 8 is introduced into the heat pump unit 1 through the hot water storage circuit and is heated by the heat pump unit 1. The heated hot water flowing out of the heat pump unit 1 flows into the upper portion of the hot water storage tank 8 through the hot water storage circuit. Therefore, hot water can be stored in the hot water storage tank 8.

(Hot water supply operation using hot water storage)
FIG. 3 is an operation explanatory diagram showing a hot water storage hot water supply operation in Embodiment 1 of the present invention. In the hot water storage hot water supply operation, when a hot water supply operation is performed, the hot water stored in the hot water storage tank 8 is used as a heat source to heat the water to be heated, and the hot water is supplied to the hot water supply target. Here, when the user opens the hot water tap or starts hot water supply to the hot water use device including the bathtub, a water flow is generated in the hot water supply pipe 22 due to the water pressure applied to the water supply pipe 20. The controller 9 detects this water flow as a hot water supply operation by the hot water supply flow rate sensor 32. During the hot water supply operation, the water to be heated supplied from the water source flows through the hot water supply circuit. The hot water supply circuit is a flow path that reaches the target of hot water supply from the water source via the water supply pipe 20, the secondary flow path of the hot water supply heat exchanger 16 and the hot water supply pipe 22 in order.

  In the hot water storage hot water supply operation, as shown in FIG. 3, the flow path switching valve 13 is switched to the second flow path configuration, the intake valve 18 is switched to the first flow path configuration, and the water introduction valve 19 is switched to the second flow path configuration. Switch to flow channel configuration. Thereby, a hot water storage hot water circulation circuit is formed between the hot water storage tank 8 and the hot water supply heat exchanger 16. The hot water storage hot water circulation circuit includes a hot water inlet / outlet 8a of the hot water storage tank 8 and a tank upper pipe 12a, a flow path switching valve 13, a hot water heating forward pipe 14, a primary flow path of the hot water heat exchanger 16, and a hot water heating return pipe. 15, a circulation passage that reaches the water introduction port 8 b of the hot water storage tank 8 through the water intake valve 18, the water pump 10, the water introduction valve 19, and the tank return pipe 11 a in this order.

  In the hot water storage hot water supply operation, the water supply pump 10 is operated in such a state that the hot water storage hot water circulation circuit is formed. Thereby, the high temperature water which retains in the upper part of the hot water storage tank 8 is introduce | transduced into the primary side flow path of the hot water supply heat exchanger 16 through the hot water storage hot water circulation circuit. This high-temperature water is returned to the lower part of the hot water storage tank 8 through the hot water storage hot water circulation circuit after exchanging heat with the water to be heated flowing in the secondary flow path of the hot water supply heat exchanger 16. As a result, the low temperature water supplied from the water source is heated by the hot water supply heat exchanger 16 to become hot water (hot water supply hot water) when flowing through the hot water supply circuit, and this hot water supply hot water is supplied to the hot water supply target by the hot water supply circuit. The Therefore, hot water can be supplied using the hot water storage hot water as a heat source. In addition, although illustration is abbreviate | omitted, you may provide the temperature adjustment mechanism in the hot water supply piping 22 which produces | generates hot water of desired temperature by mixing low temperature water with hot water supply hot water.

(Heating hot water supply operation)
FIG. 4 is an operation explanatory diagram showing a heating-use hot water supply operation in Embodiment 1 of the present invention. In the hot water supply operation using heating, when a hot water supply operation is performed, the heating target water is heated using the heated hot water heated by the heat pump unit 1 as a heat source and the hot water is supplied to the hot water supply target. More specifically, in the heating hot water supply operation, as shown in FIG. 4, the flow path switching valve 13 is switched to the third flow path configuration, the intake valve 18 is switched to the first flow path configuration, and the water introduction valve 19 is switched. Is switched to the first flow path configuration. Thereby, a heating hot water circulation circuit is formed between the heat pump unit 1 and the hot water supply heat exchanger 16. The heated hot water circulation circuit includes a water heating return pipe 12, a flow path switching valve 13, a hot water heating forward pipe 14, and a hot water heat exchanger 16 from the secondary side flow path of the water heating heat exchanger 4 of the heat pump unit 1. The secondary side of the water heating heat exchanger 4 passes through the primary side flow path, the hot water heating return pipe 15, the intake valve 18, the water pump 10, the water introduction valve 19 and the water heating forward pipe 11 in order. It is a circulation channel which returns to a channel.

  In the heating hot water supply operation, the heat pump unit 1 and the water pump 10 are operated with the heated hot water circulation circuit formed as described above. As a result, the high temperature water heated by the heat pump unit 1 is introduced into the primary flow path of the hot water supply heat exchanger 16 through the heated hot water circulation circuit. This high-temperature water is returned to the heat pump unit 1 through the heated hot water circulation circuit after exchanging heat with the water to be heated flowing in the secondary-side flow path of the hot water supply heat exchanger 16. Therefore, hot water can be supplied using the heated hot water as a heat source.

  In addition, when the stop of a water flow is detected by the hot water supply flow rate sensor 32, the above-described hot water storage hot water supply operation and heating hot water supply operation are ended. In this case, the heat pump unit 1, the water pump 10 and the like are stopped, and the flow path switching valve 13, the water intake valve 18 and the water introduction valve 19 are switched to the flow path configuration during hot water storage operation.

(Heat source switching control)
Next, heat source switching control for switching the heat source during hot water supply to either heated hot water or hot water storage hot water will be described. The heat source switching control selects either a hot water storage hot water supply operation or a heating hot water supply operation based on a target hot water supply temperature when performing hot water supply. More specifically, in the heat source switching control, when the temperature of the heated hot water is lower than the temperature of the hot water storage hot water and the target hot water temperature is set lower than a predetermined temperature reference value, the heating hot water supply operation is performed. Execute. On the other hand, when the target hot water supply temperature is set to a high temperature equal to or higher than the temperature reference value, a hot water storage hot water supply operation is executed. In addition, the temperature reference value mentioned above is preset as a temperature between the temperature of heating hot water and the temperature of hot water storage hot water, for example.

  As a specific example, for example, it is assumed that high-temperature water of 60 ° C. or higher is stored on the upper side of the hot water storage tank 8 and the boiling temperature by the heat pump unit 1 is 50 ° C. or lower. Further, it is assumed that the temperature reference value for properly using the hot water storage hot water supply operation and the heating hot water supply operation is set to 45 ° C. In this state, the target hot water supply temperature is set to a high temperature of 45 ° C. or higher in order to operate a device that uses high-temperature water, such as a dishwasher, or because the user needs high-temperature water. When the hot water supply operation is performed, the hot water storage use hot water supply operation shown in FIG. 3 is executed. Thereby, the hot water storage water of 60 degreeC or more is supplied to the primary side flow path of the hot water supply heat exchanger 16 as a heat source, for example.

  On the other hand, when hot water supply operation is performed when the target hot water supply temperature is set to a low temperature of less than 45 ° C. in order to use hot water having a relatively low temperature such as hand washing and showering, FIG. The hot water supply operation shown in FIG. Thereby, for example, heated hot water of 50 ° C. or lower is supplied to the primary flow path of the hot water supply heat exchanger 16 as a heat source.

  As described in detail above, according to the present embodiment, the heat source can be switched according to the target hot water supply temperature. Thereby, the hot hot water hot water stored in the hot water storage tank 8 is prevented from being constantly supplied to the hot water supply heat exchanger 16, and the relatively low temperature heating hot water from the heat pump unit 1 is supplied to the hot water supply heat exchanger 16. The opportunity to be supplied can be increased. For this reason, even when high-hardness water is used as the heating target water, it is possible to prevent the scale from adhering to and accumulating on the hot water supply heat exchanger 16. Therefore, the heat conduction efficiency and the hot water supply flow rate of the hot water supply heat exchanger 16 can be well maintained over a long period of time, and the life of the heat pump type hot water heater can be extended.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIGS. The feature of the present embodiment is that it includes a flow rate adjusting means for adjusting the flow rate of hot water supply hot water. FIG. 5 is a configuration diagram showing a heat pump type water heater according to Embodiment 2 of the present invention. As shown in this figure, the heat pump type water heater of the present embodiment is configured in substantially the same manner as in the first embodiment, but the secondary side inlet of the heat exchanger 16 for hot water supply in the water supply pipe 20. A flow rate adjusting valve 33 as a flow rate adjusting means is provided at a portion connected to the. The flow rate adjustment valve 33 is controlled by the control unit 9 to adjust the flow rate of the hot water flowing through the secondary flow path of the hot water supply heat exchanger 16, and is upstream of the hot water supply flow rate sensor 32 (water source Side).

In the present embodiment, the pulsation control is executed by the control unit 9 when the target hot water supply temperature is equal to or higher than a preset control start temperature. FIG. 6 is a characteristic diagram showing pulsation control of the hot water supply flow rate in the second embodiment of the present invention. As shown in this figure, in the pulsation control, the flow rate of hot water flowing through the secondary side flow path of the hot water supply heat exchanger 16, that is, the pulsation operation for increasing and decreasing the hot water supply flow rate is repeated, and the flow rate A at the time of increase is also shown. flow rate difference between the flow rate a when decreasing the _H (a H _-A) held above a preset pulsation reference value a. Here, the control start temperature is set, for example, in accordance with the minimum value of the temperature at which the scale easily precipitates in the secondary flow path of the hot water supply heat exchanger 16. Further, the pulsation reference value is set according to the minimum value of the flow rate difference (A _H −A) at which a scale adhesion suppression effect is obtained by pulsation control.

  As a specific example of executing pulsation control, for example, when hot water supply operation is performed in a case where the target hot water supply temperature is set to a high temperature of 45 ° C. or higher because hot water supply is required, As shown, the hot water supply operation using hot water is performed, and hot water is supplied using hot hot water as a heat source. At this time, the control unit 9 executes pulsation control by periodically increasing and decreasing the opening degree of the flow rate adjustment valve 33. As a result, pulsation of the flow rate is applied to the secondary side flow path of the hot water supply heat exchanger 16, so that the adhesion of the scale can be suppressed by this pulsation and the scale immediately after the adhesion can be peeled off. In this specific example, the case where the temperature reference value for properly using the hot water storage hot water supply operation and the heating hot water supply operation is set equal to the control start temperature for starting the pulsation control is illustrated. However, the present invention is not limited to this, and the temperature reference value and the control start temperature may be set to different values.

  According to the present embodiment configured as described above, when hot water is supplied using a high-temperature heat source in which scale is likely to precipitate, pulsation control can be performed to suppress scale adhesion. As a result, the scale adhesion suppression effect can be further enhanced by a synergistic effect with the control described in the first embodiment. Therefore, the heat conduction efficiency and the hot water supply flow rate of the hot water supply heat exchanger 16 can be well maintained over a long period of time, and the life of the heat pump type hot water heater can be extended.

Embodiment 3 FIG.
Next, Embodiment 3 of the present invention will be described with reference to FIG. 7 and FIG. The feature of this embodiment is that a water quality measuring means is provided in addition to the configuration of the second embodiment. FIG. 7 is a configuration diagram showing a heat pump type water heater according to Embodiment 3 of the present invention. As shown in this figure, the heat pump type hot water heater of the present embodiment is configured in substantially the same manner as in the second embodiment, but the secondary side inlet of the heat exchanger 16 for hot water supply in the water supply pipe 20. The water quality measuring means 34 is provided in the part connected to. The water quality measuring means 34 measures the quality of the hot water flowing through the secondary flow path of the hot water supply heat exchanger 16, and is composed of, for example, a pH meter, a hardness meter, or the like.

  The controller 9 constantly monitors the quality of the water flowing through the water supply pipe 20 by the water quality measurement means 34, and determines the scale precipitation tendency by, for example, inquiring the water quality measurement result with the water quality information via the network. And when it determines with a scale being easy to deposit based on the measurement result of water quality, the above-mentioned pulsation control is performed. The scale precipitation tendency is executed using, for example, data shown in FIG. FIG. 8 is a characteristic diagram illustrating the relationship between the pH and calcium hardness of hot water and the tendency of precipitation of scale. In the following description, a region where the scale precipitation tendency is larger than 1 in FIG. 8 is referred to as a “scale occurrence region”.

  The control part 9 determines with the hot water from which a scale tends to precipitate, when the measurement result of a water quality corresponds to a scale frequent occurrence area | region. In this case, even if the target hot water temperature is set to a temperature lower than the temperature reference value (or control start temperature), the above-described pulsation control is executed. As a result, the scale adhesion suppression effect can be further enhanced by a synergistic effect with the control described in the second embodiment. Therefore, the heat conduction efficiency and the hot water supply flow rate of the hot water supply heat exchanger 16 can be well maintained over a long period of time, and the life of the heat pump type hot water heater can be extended.

  In the first to third embodiments, the heat pump type hot water heater is exemplified as the hot water storage type hot water heater, but the present invention is not limited to this. That is, in the present invention, not only the heat pump unit 1 but also heating means such as an electric heating type and a fuel combustion type may be used.

1 Heat pump unit (heating source)
8 Hot water storage tank 8a Hot water inlet / outlet 8b Water inlet 8c Water outlet 9 Control unit 10 Water pump 13 Flow path switching valve (switching means)
16 Heat exchanger for hot water supply 18 Water intake valve (switching means)
19 Water introduction valve (switching means)
20 Water supply piping 22 Hot water supply piping 30 Tank temperature sensor 31 Hot water temperature sensor 32 Hot water flow rate sensor 33 Flow rate adjustment valve (flow rate adjustment means)
34 Water quality measuring means 40 Remote control (target temperature setting means)

Claims (4)

A heating source for heating hot water,
A hot water storage tank for storing hot water heated by the heating source;
A primary-side channel into which hot water is introduced from the heating source and the hot water storage tank; and a secondary-side channel into which water to be heated is introduced; the primary-side channel and the secondary-side channel; A heat exchanger for hot water supply for heating the water to be heated by performing heat exchange between,
Target temperature setting means for setting, as a target hot water temperature, a target temperature of hot water hot water flowing out from the secondary-side flow path of the hot water supply heat exchanger toward the hot water supply target;
Switching means capable of switching the hot water introduced into the primary flow path of the heat exchanger for hot water supply to either one of the heated hot water heated by the heating source and the hot water stored in the hot water storage tank. When,
When the hot water is supplied, by controlling the switching means, which hot water of the heated hot water and the hot water storage hot water is introduced into the primary flow path of the hot water heat exchanger is set as the target hot water temperature. A control unit to switch based on,
Hot water storage water heater equipped with.   In a state where the temperature of the heated hot water is lower than the temperature of the hot water storage hot water, the controller is configured to supply the heated hot water when the target hot water supply temperature is set lower than a predetermined temperature reference value. When introduced into the primary flow path of the hot water supply heat exchanger and the target hot water supply temperature is set to a high temperature equal to or higher than the temperature reference value, the hot water storage hot water is used as the primary temperature of the hot water supply heat exchanger. The hot water storage type water heater according to claim 1, which is introduced into the side flow path. A flow rate adjusting means for adjusting the flow rate of the hot water supply hot water;
The control unit repeats the operation of increasing and decreasing the flow rate of the hot water hot water by the flow rate adjusting means, and has a pulsation control execution function for maintaining a flow rate difference between the increase and decrease at a predetermined pulsation reference value or more. The hot water storage type hot water supply apparatus according to claim 1 or 2, wherein the pulsation control is executed when the target hot water supply temperature is equal to or higher than a preset control start temperature. Flow rate adjusting means for adjusting the flow rate of the hot water supply hot water;
Water quality measuring means for measuring the quality of hot water flowing through the secondary flow path of the hot water supply heat exchanger;
With
The control unit repeats the operation of increasing and decreasing the flow rate of the hot water hot water by the flow rate adjusting means, and has a pulsation control execution function for maintaining a flow rate difference between the increase and decrease at a predetermined pulsation reference value or more. The hot water storage type hot water supply apparatus according to claim 1 or 2, wherein the pulsation control is executed based on a measurement result of the water quality measuring means.

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