JP5549645B2 - Hot water storage water heater - Google Patents

Description

  The present invention relates to a hot water storage type water heater.

  In the conventional hot water storage type hot water supply apparatus, it is known to stabilize the hot water supply temperature by gradually changing the hot water flow rate at the start and stop of bath hot water filling (for example, see Patent Document 1). . Specifically, this apparatus includes a path for discharging hot water in the hot water storage tank from the hot water tap and a path for filling the hot water in the hot water storage tank to the bathtub. A four-way valve that switches the water flow path by the rotation of the valve body is disposed in the middle of the path for filling the bathtub, and the flow rate of filling the bathtub changes depending on the position of the valve body of the four-way valve. To do. According to such an apparatus, since the hot water flow rate can be gradually increased or decreased at the start and stop of bath hot water filling, unexpectedly hot water is released from the shower or hot water tap in use. Things are prevented.

JP 2009-92304 A

  However, even if the above-described configuration is used, the following problems occur depending on the system configuration of the water heater. For example, when there is a transition to boiling operation during hot water supply operation, low-temperature water remaining in the heat pump outlet piping due to circuit switching or high-temperature water heated in the heat pump unit suddenly flows into the hot water supply piping Therefore, it is assumed that the hot water temperature fluctuation in the piping occurs. In this case, the hot water temperature correction control for maintaining the user's desired hot water temperature cannot be followed, and there is a risk that extreme hot water temperature variations will occur.

  Further, for example, when low-temperature water remaining in the heat pump outlet pipe flows into the hot water supply pipe, the temperature of the hot water supplied to the external faucet or the like instantaneously decreases. Similarly, when the high-temperature water boiled by the heat pump unit flows into the hot water supply pipe, the temperature of the supplied hot water rises.

  The present invention has been made to solve the above-described problems, and provides a hot water storage type water heater that can prevent extreme fluctuations in hot water temperature when a boiling operation is performed during a hot water operation. The purpose is to provide.

  A hot water storage type hot water supply apparatus according to the present invention includes a hot water storage tank for storing hot water, a heat exchanger for boiling that heats the water in the hot water storage tank using predetermined heating means to make hot water, and one end of the hot water storage A boiling water circulation circuit is connected to the upper part of the tank, a heat exchanger for boiling is installed in the middle, and the other end is connected to the first lower part of the hot water tank, and the upper part of the hot water tank and the boiling water in the boiling water circulation circuit Installed between the heat exchanger and the flow path switching means for switching the flow path by rotation of the valve body, the tank return flow path connecting the flow path switching means and the second lower part of the hot water storage tank, and boiling Circulation pump installed between the first lower part and the heat exchanger for boiling in the water circulation circuit, the other end of the mixed hot water side flow path with one end connected to the upper part of the hot water storage tank, and one end connected to the water supply source The other end and one end of the mixed water side channel The hot water mixing valve connected to the other end of the hot water supply channel connected to the end, and the hot water mixing valve during hot water supply operation for discharging hot water in the hot water storage tank from the hot water supply terminal, Hot water control means for mixing hot water and water in the mixed water flow path to supply hot water at a predetermined temperature to the hot water flow path, and heat for boiling the valve body during the boiling operation for boiling the water in the hot water storage tank A flow in which the heat exchanger for boiling and the upper part of the hot water storage tank communicate with each other via the boiling water circulation circuit from the starting position forming a flow path form in which the exchanger and the tank return channel communicate with each other via the boiling water circulation circuit A heating operation control means for controlling the flow path switching means to rotate to the end position forming the path form and for controlling the circulation pump to operate, and the heating operation control means comprises: Request for boiling operation during hot water supply operation If it is released, the control that prolongs the time required to rotate the valve body from the start position to the end position compared to when a request for boiling operation is issued during non-execution of the hot water supply operation Means are provided.

  According to the present invention, it is possible to provide a hot water storage type water heater that can prevent extreme fluctuations in hot water temperature even when a boiling operation is performed during a hot water operation.

It is a block diagram of the hot water storage type water heater in Embodiment 1 of this invention. It is a circuit block diagram at the time of the boiling independent operation | movement of the hot water storage type water heater in Embodiment 1 of this invention. It is a circuit block diagram at the time of the hot water supply operation | movement of the hot water storage type hot water heater in Embodiment 1 of this invention. It is a circuit block diagram at the time of simultaneous operation | movement with the hot_water | molten_metal supply operation and boiling operation of the hot water storage type water heater in Embodiment 1 of this invention. It is a perspective view of the four-way valve in Embodiment 1 of this invention. It is a horizontal sectional view of the four-way valve in Embodiment 1 of the present invention. It is a horizontal sectional view of the four-way valve in Embodiment 1 of the present invention. It is a horizontal sectional view of the four-way valve in Embodiment 1 of the present invention. It is a circulation flow characteristic figure which shows the circulation flow rate of the hot water discharged from each port when the four-way valve in Embodiment 1 of the present invention is switched, (A) shows the circulation flow characteristic of a port, and (B). The circulation flow characteristics of the d port are shown respectively. It is a figure which shows the valve body position change characteristic of the four-way valve in normal flow path switching. It is a figure which shows the valve body position change characteristic of the four-way valve in the flow path switching during hot water supply operation. It is a figure which shows the valve body position change characteristic at the time of rotating the valve body position of the four-way valve in Embodiment 1 of this invention from valve body position 90 degrees to valve body position 180 degrees. It is a figure which shows the valve body position change characteristic at the time of rotating the valve body position of the four-way valve in Embodiment 1 of this invention from valve body position 90 degrees to valve body position 180 degrees.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a hot water storage type water heater 100 according to Embodiment 1 of the present invention. A hot water storage type water heater 100 shown in FIG. 1 includes a hot water storage tank unit 1 and a heat pump unit 60 configured to use a heat pump cycle. The two units 1 and 60 are connected by a heat pump inlet pipe 41 and a heat pump outlet pipe 42. The hot water storage tank unit 1 has a control unit 70 built therein. Operations of various valves, pumps and the like provided in the hot water storage tank unit 1 and the heat pump unit 60 are controlled by a control unit 70 electrically connected thereto. Hereinafter, each component of the hot water storage type water heater 100 will be described.

  The heat pump unit 60 functions as a heating means for heating (boiling) the low temperature water led from the hot water storage tank unit 1. The heat pump unit 60 includes a compressor 61, a heating heat exchanger 62, an expansion valve 63, and an air heat exchanger 64 connected in a ring shape with a refrigerant circulation pipe 65 to constitute a refrigeration cycle (heat pump cycle). The boiling heat exchanger 62 is for exchanging heat between the refrigerant flowing through the refrigerant circulation pipe 65 constituting the heat pump cycle and the low-temperature water led from the hot water storage tank unit 1. The HP outlet side thermistor 66 is a temperature sensor for detecting the temperature of the high-temperature water heated by the boiling heat exchanger 62, and is provided in the heat pump outlet pipe 42. In order to obtain high-temperature water by the heat pump unit 60, it is preferable that the heat pump cycle is operated at a pressure exceeding the critical pressure using carbon dioxide as a refrigerant.

  On the other hand, the hot water storage tank unit 1 incorporates the following various parts and piping. The hot water storage tank 10 is for storing hot water. A water supply pipe 2 for supplying city water is connected to the lower part of the hot water storage tank 10, and a hot water supply side pipe 3 for supplying the stored hot water to the outside of the water heater is connected to the upper part of the hot water storage tank 10. It is branched and connected from a tank upper pipe 43 described later. In addition, the hot water heated by the heat pump unit 60 is introduced into the hot water storage tank 10 from the upper part of the tank, and the low temperature water is introduced from the lower part of the tank through the water supply pipe 2, thereby Hot water is stored so that a temperature difference occurs in the lower part. Residual hot water thermistors 11 and 12 for detecting the temperature distribution of hot water in the hot water storage tank 10 are respectively attached to the upper and lower portions of the surface of the hot water storage tank 10. Based on the temperature distribution acquired by the remaining hot water thermistors 11 and 12, the amount of hot water in the hot water storage tank 10 is grasped, and the start and stop of the hot water boiling operation in the hot water storage tank 10 by the heat pump unit 60 is controlled. Is done.

  The hot water supply side pipe 3 branched and connected from the tank upper pipe 43 is connected to the hot water supply mixing valve 33 together with the hot water supply side pipe 4 branched from the water supply pipe 2. The hot water mixing valve 33 mixes hot water flowing through the hot water supply side pipe 3 and water flowing through the hot water supply side pipe 4 and supplies hot water adjusted to a predetermined temperature from the hot water supply pipe 5 to a hot water supply terminal such as an external water tap. To do. In addition, a hot water supply temperature thermistor 6 for detecting the temperature of hot water supplied from the hot water supply mixing valve 33 is attached to the hot water supply pipe 5.

  The hot water storage tank unit 1 includes a circulation pump 21 and a use side heat exchanger 22. The circulation pump 21 is a pump for circulating hot water through various pipes to be described later in the hot water storage tank unit 1. The use-side heat exchanger 22 uses the high-temperature water supplied from the hot water storage tank 10 and the heat pump unit 60 to heat the secondary-side heating target water (tub circulation water, heating circulation water, etc.). It is an exchanger. In the present embodiment, as a secondary side configuration of the use side heat exchanger 22, a bathtub water circulation circuit 51 that circulates hot water in the bathtub 50 will be described as an example. The use side heat exchanger 22 is installed in the middle of the bathtub water circulation circuit 51. Further, in the middle of the bathtub water circulation circuit 51, a secondary-side circulation pump 52 for circulating the bathtub water, a bathtub outlet-side thermistor 53 for detecting the temperature of the bathtub water discharged from the bathtub 50, and the bathtub water circulation circuit A water flow detection switch 54 for detecting the water flow 51 is provided.

  Next, the valves and piping included in the hot water storage tank unit 1 will be described. The hot water tank unit 1 has a three-way valve 31 and a four-way valve 32. The three-way valve 31 is a flow path switching means having two inlets (a port and b port) through which hot water flows and one outlet (c port) through which hot water flows out. Either the a port or the b port The hot water path can be switched so that hot water flows in from the water. The four-way valve 32 is a flow path switching means having two inlets (b port and c port) through which hot water flows in and two outlets (a port and d port) through which hot water flows out. , C-a route, cd route, and ba route are configured to be switchable. Details of the configuration of the four-way valve 32 will be described later.

  The hot water storage tank unit 1 includes a tank lower pipe 40, the heat pump inlet pipe 41, the heat pump outlet pipe 42, a tank upper pipe 43, a tank return pipe 44, and a use side heat exchanger primary side (heat source side) inlet pipe 45. The use side heat exchanger has a primary side outlet pipe 46 and a bypass pipe 47.

  More specifically, the tank lower pipe 40 is a flow path connecting the first lower part of the hot water storage tank 10 and the a port of the three-way valve 31, and the heat pump inlet pipe 41 is connected to the c port of the three-way valve 31 and the heat pump unit. The heat pump outlet pipe 42 is a flow path connecting the outlet side of the heat pump unit 60 and the c port of the four-way valve 32, and the tank upper pipe 43 is a four-way valve 32. The tank return pipe 44 is connected to a port of the four-way valve 32 and a return port (second lower part) provided between the center and the lower part of the hot water storage tank 10. ). The use side heat exchanger primary side inlet pipe 45 branches from between the hot water storage tank upper part of the tank upper pipe 43 and the four-way valve 32 and is connected to the primary side inlet of the use side heat exchanger 22. The use side heat exchanger primary side outlet pipe 46 is a flow path that connects the primary side outlet of the use side heat exchanger 22 and the b port of the three-way valve 31. Further, the bypass pipe 47 is a flow path that connects a portion of the heat pump inlet pipe 41 on the outlet side of the circulation pump 21 and the b port of the four-way valve 32. The circulation pump 21 is installed between the connection portion with the bypass pipe 47 on the heat pump inlet pipe 41 and the three-way valve 31.

  Next, the operation | movement operation performed in the hot water storage type water heater 100 in Embodiment 1 of this invention is demonstrated. In the hot water storage type water heater 100 according to the present embodiment, the three-way valve 31 is controlled according to the operation state shown in FIGS. The hot water passage in the hot water storage tank unit 1 is switched for use. More specifically, the “first flow path configuration” that can be selected by the three-way valve 31 means that the first lower part of the hot water storage tank 10 and the heating heat exchanger 62 connect the tank lower pipe 40 and the heat pump inlet pipe 41. The “second flow path configuration” means that the use side heat exchanger primary side outlet pipe 46 and the heating heat exchanger 62 are connected via the heat pump inlet pipe 41. It is a flow path form that communicates.

  Furthermore, in the hot water storage type hot water heater 100 of the present embodiment, the four-way valve 32 is controlled according to the operation state shown in FIGS. The hot water flow path in the hot water storage tank unit 1 is switched and used. More specifically, the “first flow path configuration” that can be selected by the four-way valve 32 means that the heating heat exchanger 62 and the upper part of the hot water storage tank 10 are connected via the heat pump outlet pipe 42 and the tank upper pipe 43. The “second flow path configuration” is a flow channel configuration in which the boiling heat exchanger 62 and the tank return pipe 44 communicate with each other via the heat pump outlet pipe 42. The “third flow path configuration” is a flow channel configuration in which the bypass pipe 47 and the tank return pipe 44 communicate with each other.

  FIG. 2 is a circuit configuration diagram of the hot water storage type water heater 100 according to Embodiment 1 of the present invention at the time of a single heating operation. In addition, the boiling-up single operation here is a thing in which the boiling-up operation which uses the heat pump unit 60 to boil the water in the hot water storage tank 10 is performed independently. During this heating operation alone, the three-way valve 31 communicates with the a port and the c port so that the b port is closed (that is, the first flow path configuration of the three-way valve 31 is selected). Be controlled. Accordingly, the tank lower pipe 40 and the heat pump inlet pipe 41 communicate with each other, and the flow path from the usage side heat exchanger 22 is blocked by closing the usage side heat exchanger primary side outlet pipe 46 side. Further, during the boiling-only operation, the four-way valve 32 is selected so that the c port and the d port communicate with each other and the a port and the b port are closed (that is, the first flow path configuration of the four-way valve 32 is selected). To be controlled). Thereby, the heat pump outlet pipe 42 and the tank upper pipe 43 communicate with each other, and the flow path to the second lower part of the hot water storage tank 10 is blocked by closing the tank return pipe 44 side.

  The boiling-up single operation is executed by starting the operation of the circulation pump 21 and the heat pump unit 60 in a state where the three-way valve 31 and the four-way valve 32 are controlled as described above. As a result, the low-temperature water flowing out from the first lower part of the hot water storage tank 10 is guided to the heat pump unit 60 via the tank lower pipe 40, the three-way valve 31, the circulation pump 21 and the heat pump inlet pipe 41, and heat exchange for boiling is performed. After being heated in the vessel 62 to become hot water, it flows into the hot water storage tank 10 from the upper part of the hot water storage tank 10 through the heat pump outlet pipe 42, the four-way valve 32 and the tank upper pipe 43 and is stored. Here, the hot water circulation path shown in FIG. 2 is referred to as a “boiling water circulation circuit”. By performing such boiling-up single operation, high temperature water is stored from the upper layer inside the hot water storage tank 10, and this high temperature water layer gradually becomes thicker.

  FIG. 3 is a circuit configuration diagram at the time of hot water supply operation of hot water storage type hot water heater 100 according to Embodiment 1 of the present invention. The hot water supply operation here refers to an operation of adjusting hot water stored in the hot water storage tank 10 to a hot water temperature desired by the user and supplying hot water to an external faucet or shower through the hot water supply pipe 5. . This hot water supply operation is started when the user opens an arbitrary faucet, and the hot water stored in the hot water storage tank 10 and the water supplied from the water supply pipe 2 are respectively connected to the hot water supply side pipe 3 and the hot water supply side. It is supplied to the hot water supply mixing valve 33 through the pipe 4. In the hot water supply mixing valve 33, the hot water temperature of the hot water is adjusted to the hot water temperature desired by the user by controlling the mixing ratio of the supplied high temperature water and water. During the hot water supply operation, the hot water temperature of the hot water is constantly monitored by the hot water temperature thermistor 6 to change the amount of hot water, the temperature of the hot water supplied from the hot water storage tank 10, and the water supplied from the water supply pipe 2. By always controlling the mixing ratio of the hot water supply mixing valve 33 according to the temperature fluctuation, hot water adjusted to a constant hot water temperature is supplied to an external faucet or shower.

  During this hot water supply operation, the three-way valve 31 is controlled such that the first flow path configuration is selected. Accordingly, the tank lower pipe 40 and the heat pump inlet pipe 41 communicate with each other, and the flow path from the usage side heat exchanger 22 is blocked by closing the usage side heat exchanger primary side outlet pipe 46 side. During the hot water supply operation, the four-way valve 32 is controlled so that the second flow path configuration is selected. Thereby, the heat pump outlet pipe 42 and the tank return pipe 44 communicate with each other, and the flow path to the upper part of the hot water storage tank 10 is blocked by closing the tank upper pipe 43 side. In this way, the flow path from the use side heat exchanger 22 and the flow path to the upper part of the hot water storage tank 10 are blocked, thereby preventing the hot water from flowing into these devices.

  FIG. 4 is a circuit configuration diagram at the time of simultaneous operation of the hot water supply operation and the boiling operation of hot water storage type water heater 100 according to Embodiment 1 of the present invention. Here, the simultaneous operation of the hot water supply operation and the boiling operation is an operation operation in which the hot water supply operation shown in FIG. 3 and the single heating operation shown in FIG. 4 are performed simultaneously. This operation is performed simultaneously when a boiling operation request is issued by a user operation or when a boiling operation request is issued due to a decrease in high-temperature water in the hot water storage tank 10 during a hot water supply operation. During the simultaneous operation of the hot water supply operation and the boiling operation, the three-way valve 31 is controlled to the first flow path configuration. Accordingly, the tank lower pipe 40 and the heat pump inlet pipe 41 communicate with each other, and the flow path from the usage side heat exchanger 22 is blocked by closing the usage side heat exchanger primary side outlet pipe 46 side. In addition, during the simultaneous operation of the hot water supply operation and the boiling operation, the four-way valve 32 is controlled to the first flow path configuration. Thereby, the heat pump outlet pipe 42 and the tank upper pipe 43 communicate with each other, and the flow path to the second lower part of the hot water storage tank 10 is blocked by closing the tank return pipe 44 side. In the simultaneous operation of the hot water supply operation and the boiling operation, unlike the hot water supply operation shown in FIG. 3, mixed water of hot water from the hot water storage tank 10 and circulating water from the heat pump unit 60 is supplied to the hot water supply side pipe 3. Supplied. Even during the simultaneous operation of the hot water supply operation and the boiling operation, the hot water supply mixing valve 33 is controlled in the same manner as when the hot water supply operation is being performed alone, and the hot water supply is adjusted to a desired hot water temperature. The action is executed.

  Here, the configuration of the four-way valve 32 will be described in detail with reference to FIGS. FIG. 5 is a perspective view of the four-way valve 32 in Embodiment 1 of the present invention, and FIGS. 6 to 8 are horizontal sectional views of the four-way valve 32 shown in FIG. As shown in these drawings, the four-way valve 32 is configured by pipes 32a, 32b, 32c, and 32d of a, b, c, and d ports, a valve frame 32e, a stepping motor 32f, a rotating shaft 32g, and a valve body 32h. Yes. The valve body 32h is accommodated in the valve frame 32e, and is connected to the stepping motor 32f via the rotating shaft 32g. When the stepping motor 32f is driven, the valve body 32h rotates around the rotation shaft 32g. Thereby, the port connected through the communication part 32i shape | molded in the valve body 32h is switched. 6 is a position where the a port and the c port of the four-way valve 32 communicate with each other and the b port and the d port are closed (hereinafter, this valve body position is referred to as “valve body position 90”. For example, during the hot water supply operation, the valve body position is controlled to 90 °. 7 is a position where the c-port and d-port of the four-way valve 32 communicate with each other and the a-port and b-port are closed (hereinafter, this valve-body position is referred to as “valve-body position 180”). For example, during the heating operation, the valve body 32h is rotated from the valve body position 90 ° shown in FIG. 6 to the valve body position 180 ° shown in FIG. Further, the valve body position shown in FIG. 8 represents the valve body position 135 ° in the course of switching from the valve body position 90 ° to the valve body position 180 °. When the valve body position is 135 °, the a port, the c port, and the d port communicate with each other, and the b port is closed.

  FIG. 9 is a circulation flow characteristic diagram showing the circulation flow rate of hot water discharged from each port when the four-way valve 32 is switched from the valve body position 90 ° to the valve body position 180 °. The circulation flow characteristics are shown, and (B) shows the circulation flow characteristics of the d port. As shown in this figure, the four-way valve 32 is characterized in that, for example, when the circuit is switched from the valve body position 90 ° shown in FIG. 6 to the valve body position 180 ° shown in FIG. As shown to (A), it becomes a decreasing tendency and it will be in the obstruction | occlusion state finally by 180 degrees of valve body positions. On the other hand, the circulating flow rate of the d port tends to increase as shown in FIG. 9B, and finally reaches the maximum flow rate at the valve body position 180 °.

  Next, a characteristic operation of the hot water storage type hot water heater 100 according to Embodiment 1 of the present invention will be described. FIG. 10 is a diagram illustrating the valve body position change characteristic of the four-way valve 32 in normal flow path switching. As shown in this figure, when there is a user operation or a boiling operation instruction from the control unit 70, the circulation pump 21 is operated and the four-way valve 32 is switched from the valve body position 90 ° to the valve body position 180 °. It is done. At this time, when the hot water supply operation is not performed, normal flow path switching is performed in which the four-way valve 32 is quickly switched (for example, 10 seconds) from the valve body position 90 ° to the valve body position 180 °.

  On the other hand, FIG. 11 is a diagram showing a valve body position change characteristic of the four-way valve 32 in the flow path switching during the hot water supply operation. As shown in this figure, when a hot water supply operation is performed when there is a user operation or a boiling operation instruction from the control unit 70, the valve body 32h is compared with the normal flow path switching shown in FIG. The time required for switching is prolonged (for example, 40 seconds). As described above, the circulation flow rate of the d port when the four-way valve 32 is switched from the valve body position 90 ° to the valve body position 180 ° tends to increase as it rotates. Therefore, as shown in FIG. 11, the extreme flow rate fluctuation of the circulation flow rate of the d port of the four-way valve 32 is suppressed by slowing the rotation speed of the valve body 32h of the four-way valve 32 as compared with the normal flow path switching. It becomes possible to do. Thereby, the rapid hot water temperature in the hot water supply side pipe 3 due to a large amount of low temperature water remaining in the heat pump outlet pipe 42 and high temperature water boiled up in the heat pump unit 60 flowing into the hot water supply side pipe 3. Since the fluctuation can be suppressed, the hot water temperature correction control of the hot water mixing valve 33 can be sufficiently followed to keep the hot water temperature fluctuation during use extremely small.

  In addition, the valve body position change characteristic of the four-way valve 32 may be changed according to the hot water supply flow rate during the hot water supply operation. That is, for example, when the hot water supply flow rate during hot water supply operation is 10 liters / minute, the rotation time of the valve body 32h is 60 seconds, and when the hot water supply flow rate is 5 liters / minute, the valve body 32h is rotated. By setting the time to 90 seconds, the ratio of the amount of inflow from the heat pump unit 60 side with respect to the entire hot water flow rate does not change greatly between the case where the flow rate is low and the case where the flow rate is high, and the hot water flowing in the hot water supply side pipe 3 It is possible to stabilize the hot water supply temperature by suppressing temperature fluctuations.

  Moreover, the flow path switching operation during the hot water supply operation may be performed intermittently. FIG. 12 is a diagram illustrating a valve body position change characteristic when the valve body position of the four-way valve 32 is rotated from the valve body position 90 ° to the valve body position 180 °. As shown in this figure, by intermittently switching channels every predetermined time (for example, 10 seconds), the time required for switching can be effectively prolonged, and the same effect as described above can be obtained. it can.

  As an example of intermittently performing the flow path switching operation during the hot water supply operation, for example, the hot water supply temperature is constantly monitored by the hot water supply temperature thermistor 6, and when the temperature desired by the user is being supplied, the four-way valve 32 is kept constant. When the opening degree (for example, 10 °) is rotated and the temperature desired by the user is not supplied, it is possible to wait for the rotation to stabilize until the temperature desired by the user is stabilized by the temperature correction control of the hot water supply mixing valve 33. Good.

  In addition, as another example of intermittently performing the flow path switching operation during the hot water supply operation, when the time required for rotation is limited (for example, 20 seconds) and the temperature desired by the user is supplied When the four-way valve 32 is rotated by a certain degree of opening (for example, 10 °) and the temperature desired by the user is not supplied, the rotation may be waited until the set rotation standby time elapses. .

  Furthermore, as shown in FIG. 9, the four-way valve 32 has an opening region where the flow rate increases extremely and an opening region where the flow rate does not change extremely. Therefore, when the flow path switching operation at the time of the hot water supply operation is performed using such a four-way valve 32, the flow rate characteristics depending on the opening degree of the valve body 32h of the four-way valve 32 are set every predetermined time (for example, 10 seconds). The rotation width may be variably set. Specifically, for example, an opening region where the flow rate increases extremely is set to a small opening (for example, 5 °), and an opening region where the flow rate does not change extremely is set to a large opening (for example, 20 °). It is good as well. Thereby, the temperature fluctuation of the hot water flowing through the hot water supply side pipe 3 due to the rotation of the four-way valve 32 can be further suppressed, and the hot water supply temperature can be stabilized.

  Alternatively, the number of intermittent operations may be set variably using the flow rate characteristic depending on the opening degree of the valve body 32h of the four-way valve 32. FIG. 13 is a diagram illustrating a valve body position change characteristic when the valve body position of the four-way valve 32 is rotated from the valve body position 90 ° to the valve body position 180 °. As shown in this figure, the operation from the start to the end of switching is divided into a plurality of regions, and the region from the beginning of switching to the occurrence of extreme flow rate fluctuation is defined as the first region (for example, 90 ° to 120 °) once. The four-way valve 32 is operated in the operation (for example, 30 °) and waits for a certain time (for example, 7.5 seconds) after the operation. Next, a region where extreme flow rate fluctuations occur from the end point (here, 129 °) of the first region is defined as the second region (for example, 120 ° to 160 °), and the opening is smaller than the first region (for example, 10 °). The operation is performed intermittently in a plurality of times, and after the operation, each device waits for a predetermined time (for example, 2.5 seconds). Finally, the third region (here 160 ° to 180 °) is defined as the third region (here 160 ° to 180 °) from the end point of the second region (here 160 °) to the opening until the switching is completed. Switching to the end point of the third region (here, 180 °) is performed by one operation (here, 20 °). Thereby, since only the region where the temperature fluctuation influence during hot water supply due to the rotation of the four-way valve 32 is large can be operated finely, the temperature fluctuation of the hot water flowing in the hot water hot water side pipe 3 can be further suppressed. Moreover, since the region where the influence of temperature fluctuation is small can be quickly rotated, the operation time of the four-way valve 32 can be shortened.

  Furthermore, in the control of the first embodiment described above, the operation of the four-way valve 32 is set to a constant opening degree set in advance, but the flow rate from the heat pump inlet pipe 41 to the tank upper pipe 43 and the tank when the four-way valve 32 is switched are set. The flow rate ratio to the flow rate to the return pipe 44 is known in advance by experiments, and the opening degree when the four-way valve 32 is operated during hot water supply is such that the temperature fluctuation of the hot water supply obtained in the experiment is the smallest. You may set to the opening degree used as variation | change_quantity.

  Further, in the first embodiment described above, the operation when the valve body position of the four-way valve 32 is switched from 90 ° to 180 ° has been described. However, hot water supply generated when the valve body position is switched from 180 ° to 90 °. The same switching method of the four-way valve 32 as described above can be applied to temperature fluctuations.

3 Hot water supply side pipe 4 Hot water supply side pipe 5 Hot water supply pipe 10 Hot water storage tank 21 Circulation pump 22 Use side heat exchanger 32 Four-way valve (flow path switching means)
33 Hot-water supply mixing valve 40 Tank lower piping (boiling water circulation circuit)
41 Heat pump inlet piping (boiling water circulation circuit)
42 Heat pump outlet piping (boiling water circulation circuit)
43 Tank upper piping (boiling water circulation circuit)
44 Tank return pipe 60 Heat pump unit (heating means)
62 Heat exchanger for boiling

Claims (7)

A hot water storage tank for storing hot water,
A boiling heat exchanger that heats the water in the hot water storage tank using predetermined heating means to form high-temperature water;
A boiling water circulation circuit in which one end is connected to the upper part of the hot water storage tank, the boiling heat exchanger is installed in the middle, and the other end is connected to the first lower part of the hot water storage tank;
A flow path switching means installed between the upper part of the hot water storage tank and the boiling heat exchanger in the boiling water circulation circuit and switching the flow path by rotation of a valve body;
A tank return flow path connecting the flow path switching means and the second lower part of the hot water storage tank;
A circulation pump installed between the first lower part and the heating heat exchanger in the boiling water circulation circuit;
The other end of the mixed water side flow path whose one end is connected to the upper part of the hot water storage tank, the other end of the mixed water side flow path whose one end is connected to the water supply source, and the hot water supply flow path whose one end is connected to the hot water supply terminal A hot water mixing valve connected to the other end of the
During a hot water supply operation for discharging hot water in the hot water storage tank from the hot water supply terminal, the hot water mixing valve is controlled to mix the hot water in the mixed hot water channel and the water in the mixed water flow channel, thereby supplying hot water at a predetermined temperature. Control means for supplying hot water to the hot water supply flow path,
During the boiling operation for boiling water in the hot water storage tank, the valve body starts to form a flow path configuration in which the heat exchanger for boiling and the tank return flow path communicate with each other via the boiling water circulation circuit Controlling the flow path switching means so that the boiling heat exchanger and the upper part of the hot water storage tank are rotated to an end position that forms a flow path form communicating with the boiling water circulation circuit. And a heating operation control means for controlling the circulating pump to operate,
When the boiling operation request is issued during execution of the hot water supply operation, the control unit during the boiling operation is when the request for the boiling operation is issued during non-execution of the hot water operation. In comparison, the hot water storage type hot water heater is provided with a control means for prolonging the time required for rotating the valve body from the start position to the end position.   The control means intermittently moves the valve body in the flow path switching means from the start position to the end position multiple times when a request for the boiling operation is issued during execution of the hot water supply operation. The hot water storage type water heater according to claim 1, wherein the hot water storage type water heater is rotated separately.   The control means variably sets a rotation width per rotation according to the position of the valve body when the valve body in the flow path switching means is intermittently rotated a plurality of times. The hot water storage type water heater according to claim 2.   When the control means rotates the valve body in the flow path switching means intermittently in a plurality of times, the control means moves the valve body with a first rotation width from the start position to the first reference position. The valve body is rotated by a second rotation width smaller than the first rotation width from the first reference position to the second reference position, and from the second reference position to the end position. 4. The hot water storage type hot water heater according to claim 3, wherein the valve body is rotated with a third rotation width larger than the second rotation width. A determination means for determining whether or not the temperature of hot water discharged from the hot water supply terminal during the hot water supply operation is the predetermined temperature;
The control means is a case where a request for the boiling operation is issued during execution of the hot water supply operation, and the determination means determines that the temperature of hot water discharged from the hot water supply terminal is not the predetermined temperature. In this case, the hot water storage type hot water heater according to any one of claims 1 to 4, characterized in that the rotation of the valve body in the flow path switching means is temporarily stopped.   6. The control unit according to claim 1, wherein the control unit variably sets a time required for rotating the valve body from the start position to the end position in accordance with a hot water supply amount of the hot water supply operation. The hot water storage type water heater according to claim 1.   When the control means rotates the valve body in the flow path switching means intermittently in a plurality of times, the flow rate of hot water flowing from the flow path switching means to the upper part of the hot water storage tank and the second lower part 3. The hot water storage type hot water heater according to claim 2, wherein a rotation width per one time is variably set so that a change amount of the ratio becomes constant in accordance with a ratio with a flow rate of hot water flowing into the water.

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