JP5737133B2 - Hot water storage water heater - Google Patents

Description

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

  Conventional hot water storage type water heaters are known that control fluctuations in hot water temperature by controlling the flow path switching time of the four-way valve when hot water is filled during hot water supply (for example, Patent Document 1). This apparatus includes a path for discharging hot water in a hot water storage tank through a hot water supply mixing valve, and a path for filling the bathtub with hot water through a bath mixing valve and a four-way valve. The four-way valve can switch the water flow path by rotating the valve body. According to such a device, when a hot water command is generated during hot water supply, the opening of the four-way valve is operated at a low speed, the hot water flow rate is increased, and the decrease speed is decreased, so that hot water starts. It is possible to prevent a situation where the hot water temperature fluctuates during the stop.

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, during the hot water supply operation (state shown in FIG. 3), when the temperature of the hot water in the pipe decreases due to natural heat dissipation and the freeze prevention operation is required, and the heat pump pipe freeze prevention operation is activated, the operation goes to the heat pump unit 60. While the hot water in the return pipe is circulated and heated, the hot water in the tank upper pipe 43 remains at a low temperature. From this state, the circuit of the four-way valve 32 is switched at a low speed as in the prior art (hot water from the circulating heat pump unit 60 is discharged to the tank upper pipe 43 side) to prevent freezing. The remaining low-temperature water flows into the hot water supply side pipe 3 and increases its flow rate. Then, the four-way valve 32 is fully opened, and the heated hot water flows in. Then, the hot water temperature fluctuation in the hot water supply side pipe 3 and the flow rate change occur simultaneously in a short time, and as a result, the hot water temperature correction control by the hot water mixing valve 33 cannot be followed, and the desired hot water temperature of the user May not be able to supply hot water, and extreme fluctuations in hot water temperature may occur.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a hot water storage type hot water heater capable of preventing extreme fluctuations in hot water temperature.

  A hot water storage tank, a water supply flow path for supplying water to the hot water storage tank, a heat exchanger for boiling water to heat the water in the hot water storage tank into high temperature water, and one end connected to the upper part of the hot water storage tank, switching the flow path in the middle Between the boiling water circulation path connected to the first lower part of the hot water storage tank via the means and the heating heat exchanger, and between the boiling heat exchanger and the first lower part of the hot water storage tank in the boiling water circulation path An installed circulation pump, a lower return flow path connecting the flow path switching means and the second lower part of the hot water storage tank, and the flow path switching means are composed of a heating heat exchanger and an upper portion of the hot water storage tank for circulating the boiling water. A first flow path configuration communicating through a flow path, and a second flow path configuration in which a heating heat exchanger and a lower return flow path are communicated via a boiling water circulation flow path. A means that can be switched by rotation, in the boiling water circulation channel. A mixed water side branching from between the connection part between the flow path switching means and the upper part of the hot water storage tank and connected to the hot water mixing means, and a mixed water side branched from the water supply flow path and connected to the hot water mixing means Control the flow path, the hot water supply flow path connected from the hot water mixing means to the external faucet, and the hot water mixing means to mix the hot water in the mixed hot water side flow path and the mixed water side flow path, The hot water supply control means for performing the hot water supply operation to supply the stopper and the first flow path form is formed from the rotation start position at which the valve body forms the second flow path form during the freeze prevention operation of the boiling water circulation flow path. Freezing prevention operation for controlling the flow path switching means so as to rotate to a flow rate regulating position where the flow rate of hot water flowing by the valve body in the flow path switching means is reduced before the rotation end position to be performed A time control means, and the freeze prevention time control means is executing a hot water supply operation. When performing the freeze prevention operation, it is provided with a control means for prolonging the time for rotating the valve body from the start position to the flow rate restriction position as compared to when performing the hot water supply operation non-execution. It is.

  According to the present invention, it is possible to provide a hot water storage type hot water heater capable of preventing extreme fluctuations in hot water temperature.

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 freeze prevention operation | movement of the boiling water circulation flow path in Embodiment 1 of this invention. It is a circuit block diagram at the time of the hot water supply operation | movement in Embodiment 1 of this invention. It is a circuit block diagram at the time of simultaneous operation | movement of the hot water supply operation | movement in Embodiment 1 of this invention, and the freezing prevention operation | movement of a boiling water circulation flow path. It is a perspective view of the four-way valve in Embodiment 1 of this invention. It is a horizontal sectional view of a and c port communication state (valve body position 90 degrees) of a four-way valve. It is a horizontal sectional view of c and d port communication state (valve body position 180 degrees) of a four-way valve. It is a horizontal sectional view of the c and d port communication state (valve element position A °) of the four-way valve. It is a horizontal sectional view of a, c, d port communication state (valve body position B °) of the four-way valve. FIG. 4 is a flow characteristic diagram (A) of the a port and a flow characteristic diagram (B) of the d port with respect to the valve body position of the four-way valve. It is a figure which shows the valve body position of the four-way valve at the time of normal switching, and the characteristic of elapsed time. It is a figure which shows the characteristic of the valve body position and elapsed time of a four-way valve at the time of flow path switching during hot water supply operation. It is a figure which shows the characteristic of a valve body position at the time of rotating a four-way valve by dividing into multiple times intermittently and elapsed time.

  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. In the explanation of the operation, the piping through which the hot water flows is indicated by a thick line, and the flow direction is indicated by an arrow in the vicinity of each piping.

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 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. Further, the hot water storage unit 1 has a control unit 70 built therein. Operations of various valves, pumps, and the like included in the hot water storage 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 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 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 unit 1. The heat pump 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 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 from the tank upper pipe 43 and connected. The hot water storage tank 10 is supplied with hot water heated by the heat pump unit 60 from the upper part of the tank, and low temperature water is supplied from the lower part of the tank through the water supply pipe 2 so that the upper and lower parts in the tank are Hot water is stored so that a temperature difference occurs. Further, the remaining hot water thermistors 11 and 12 for detecting the temperature distribution of hot water in the hot water storage tank 10 by changing the mounting height are attached to 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 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 supply mixing valve 33 mixes the hot water flowing through the hot water supply side pipe 3 and the water flowing through the hot water supply side pipe 4, and supplies the hot water adjusted to a predetermined temperature to the external water faucet or the like via the hot water supply pipe 5. . A hot water supply temperature thermistor 6 for detecting the temperature of the mixed hot water is attached to the hot water supply pipe 5.

  In addition, a circulation pump 21 and a bath-side heat exchanger 22 are built in the hot water storage unit 1. The circulation pump 21 is provided on a heat pump inlet pipe 41 between a later-described three-way valve 31 and a heating heat exchanger 62 in the hot water storage unit 1, and is a pump for circulating hot water through each pipe. The bath-side heat exchanger 22 uses the high-temperature water supplied from the hot water storage tank 10 or the heat pump unit 60 to heat the water to be heated on the secondary side (tub circulation water, heating circulation water, etc.). It is an exchanger. In the present embodiment, as a secondary side configuration of the bath-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 bath-side heat exchanger 22 is installed in the middle of the bathtub water circulation circuit 51. Further, a secondary circulation pump 52 for circulating the bathtub water and a bathtub outlet side thermistor 53 for detecting the temperature of the bathtub water discharged from the bathtub 50 are installed in the middle of the bathtub water circulation circuit 51. Yes.

  Next, the valves and piping provided in the hot water storage unit 1 will be described. The hot water storage 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. , A-b route, a-c route, and cd route, the flow path form is configured to be switchable.

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

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

  FIG. 2 is a circuit configuration diagram at the time of freeze prevention operation of the boiling water circulation passage of hot water storage type hot water heater 100 according to Embodiment 1 of the present invention. The freeze prevention operation of the boiling water circulation flow path here refers to the prevention of freezing of hot water mainly in the tank upper pipe 43 by boiling and circulating the water in the hot water storage tank 10 using the heat pump unit 60. It is a driving to be performed. During the freeze prevention operation of the boiling water circulation channel, the three-way valve 31 is controlled so that the a port and the c port communicate with each other and the b port is closed. As a result, the tank lower pipe 40 and the heat pump inlet pipe 41 communicate with each other, and the flow path from the bath side heat exchanger 22 is blocked by closing the bath side heat exchanger primary side outlet pipe 46 side. Further, during the freeze prevention operation of the boiling water circulation flow path, the four-way valve 32 is controlled so that the c port and the d port communicate with each other and the a port and the b port are closed. As a result, 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 shut off by closing the bypass pipe 44 side.

  This freezing prevention operation of the boiling water circulation flow path is independent or heat pump pipe freezing prevention operation (the three-way valve 31 is controlled so that the a port and the c port communicate with each other and the b port is closed, and the four-way valve 32 is set to a The circulation pump 21 and the heat pump unit 60 are operated in a state where the port and the c port are in communication and the b port and the d port are closed, and hot water is supplied from the first lower part of the hot water storage tank 10 via the heat pump unit 60. Circulated to the second lower part of the hot water storage tank 10 and operation for preventing freezing from the heat pump inlet pipe 41 to the heat pump outlet pipe 42) is performed for a predetermined short time.

  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, the tank upper pipe 43 is prevented from freezing by passing through the heat pump outlet pipe 42, the four-way valve 32, and the tank upper pipe 43 as hot water.

  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. In the hot water supply operation, high temperature water stored in the hot water storage tank 10 and water supplied from the water supply pipe 2 are supplied to the hot water supply mixing valve 33 through the hot water supply side pipe 3 and the hot water supply side pipe 4, respectively. This is an operation of supplying hot water adjusted to a user's desired hot water temperature 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 temperature to supply hot water is controlled by controlling the mixing ratio of the high temperature water and water flowing into the hot water supply mixing valve 33 according to the hot water supply temperature set by the user. Is adjusted to the hot water temperature desired by the user. During the hot water supply operation, the temperature of hot water supplied to an external faucet or shower is constantly monitored by the hot water supply temperature thermistor 6, fluctuations in the amount of hot water supplied, hot water supplied from the hot water storage tank 10, and water supply By constantly controlling the mixing ratio of the hot water supply mixing valve 33 in accordance with the temperature fluctuation of the water supplied from the pipe 2, hot water adjusted to a constant hot water temperature is supplied to an external faucet or shower.

  During the hot water supply operation, the same amount of hot water stored in the hot water storage tank 10 is supplied from the water supply pipe 2 to the lower part of the hot water storage tank 10. The three-way valve 31 during the hot water supply operation is controlled so that the a port and the c port communicate with each other and the b port is closed. The four-way valve 32 during the hot water supply operation is controlled so that the a port and the c port communicate with each other and the b port and the d port are closed. Thereby, the hot water inflow to the upper part of the bath side heat exchanger 22 and the hot water storage tank 10 is prevented.

  Next, FIG. 4 is a circuit configuration diagram at the time of simultaneous operation of the hot water supply operation of hot water storage type hot water heater 100 and the freeze prevention operation of the boiling water circulation passage in the first embodiment of the present invention. The simultaneous operation of the hot water supply operation and the freeze prevention operation of the boiling water circulation flow path here is an operation operation in which the hot water supply operation shown in FIG. 3 and the freeze prevention operation of the boiling water circulation flow path shown in FIG. In this case, for example, during the hot water supply operation, the heat pump outlet side thermistor 66 becomes lower than a predetermined temperature in a low outside air environment, and the control unit 70 that detects the temperature rises from the heat pump pipe freezing prevention operation described above. This is a case where the freeze prevention operation is implemented. During the simultaneous operation of the hot water supply operation and the freeze prevention operation of the boiling water circulation flow path, the three-way valve 31 is controlled so that the a and c ports communicate and the b port is closed, and the four-way valve 32 has the a, c, and d ports. The communication is controlled so that the b port is closed. As a result, the heat pump outlet pipe 42, the tank return pipe 44, and the tank upper pipe 43 communicate with each other with a smaller flow path cross-sectional area than when the flow path is completely switched, and the flow path on the bypass pipe 47 side Blocked. Details of the flow path adjustment by the operation of the valve body 32h in the four-way valve 32 in this case will be described later.

  In the simultaneous operation of the hot water supply operation and the freeze prevention operation of the boiling water circulation flow path, unlike the hot water supply operation shown in FIG. 3, the hot water supply side pipe includes high-temperature water from the hot water storage tank 10 and residual water in the tank upper pipe 43. Mixed water with the circulating water from the heat pump unit 60 is supplied. Even during the simultaneous operation of the hot water supply operation and the freezing prevention operation of the boiling water circulation flow path, the hot water supply mixing valve 33 is controlled in the same manner as when the hot water supply operation is executed alone, and the hot water supply is desired. The operation of adjusting to the hot water temperature 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 9 are horizontal sectional views of the four-way valve 32 shown in FIG. As shown in FIG. 5, the four-way valve 32 is constituted by piping 32a, 32b, 32c, 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. A stepping motor 32f is connected to the valve body 32h via a rotating shaft 32g at the upper part of the valve frame 32e. Accordingly, the valve body 32h is rotated about the rotation shaft 32g by the rotation of the stepping motor 32f, and the flow path in the four-way valve 32 is switched through the communication portion 32i formed in the valve body 32h. ing. 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, this valve body position is used during a single hot water supply operation. 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 freeze-preventing operation of the boiling water circulation passage during the hot water supply operation, the valve body 32h is changed from the valve body position 90 ° shown in FIG. 6 to the valve body position 180 ° shown in FIG. Is rotated.

  Further, the valve body position shown in FIG. 8 is such that the c-port and d-port of the four-way valve 32 communicate with each other in a state where the flow passage cross-sectional area is smaller than that in the case where the valve body position 180 ° in FIG. b indicates a position where the port b is closed (hereinafter, this valve body position is referred to as “A °”). For example, during the freeze-preventing operation of the boiling water circulation channel, the valve body position A ° is changed from 90 °. Until the valve body position A ° is intermittently divided into a plurality of times and then the valve body position A ° is returned to the valve body position 90 °. In the state of the valve body position A °, the flow passage cross-sectional area is small as compared with the case of the valve body position 180 ° as described above, so the amount of hot water flowing from the c port to the d port through the four-way valve 32 is fully opened. It becomes possible to control less than in the case where the valve body position is 180 °. Furthermore, by rotating the valve body position 90 ° to the valve body position A ° intermittently in a plurality of times, the amount of hot water flowing from the c port to the d port can be further controlled. Become.

  Further, the valve body position shown in FIG. 9 is a valve body position on the way from the valve body position 90 ° to the valve body position A ° (hereinafter, this valve body position is referred to as “B °”. 90 ° <B ° < A ° <180 °). At the valve body position B °, the a port, c port, and d port partially communicate with each other and the b port is closed. Even in the state of the valve body position B °, the flow passage cross-sectional area is smaller than that in the case of the valve body position A °, so that the amount of hot water flowing through the four-way valve 32 from the c port to the d port is fully opened. It is less than the case of the valve body position 180 ° and the case of the valve body position A °.

  FIG. 10 (A) is a characteristic diagram showing the relationship between the flow rate of hot water passing through the a port and the valve body position when the circuit of the four-way valve 32 is normally switched, such as during a non-hot water supply operation. ) Is a characteristic diagram showing the relationship between the flow rate of hot water passing through the d port and the valve element position. 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. 7, the four-way valve 32 has a circulation flow rate of 90 ° as shown in FIG. The amount of change at an intermediate position tends to increase with respect to the change in flow rate with respect to the amount of change in the valve body position at the initial position from 180 to 180 ° and at a position close to 180 °. On the contrary, the circulating flow rate of the d port tends to increase, 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. 11 is a diagram showing the relationship between the change in the valve body position of the four-way valve 32 and the time required (elapsed time). The characteristics at the time of normal circuit switching from the valve body position 90 ° to the valve body position 180 ° are shown. Show. As shown in this figure, when there is an instruction to prevent freezing of the boiling water circulation flow path from the controller 70 during the non-hot water supply operation, the four-way valve 32 is moved from the valve body position 90 ° to the valve body position 180 °. Perform channel switching. At this time, the normal flow path switching in which the four-way valve 32 is quickly switched (for example, 15 seconds) from the valve body position 90 ° to the valve body position 180 ° is performed, and a necessary and sufficient flow rate can be secured in a short time.

  On the other hand, FIG. 12 is a diagram showing the relationship between the change in the valve element position of the four-way valve 32 and the time required for the flow path switching during the hot water supply operation. As shown in FIG. 12, when there is an instruction to prevent freezing of the boiling water circulation channel from the control unit 70, the hot water supply operation is performed. The rotation is delayed to increase the time required for switching (for example, 50 seconds), the valve body position is rotated to the state of A ° in FIG. 8, and the flow rate from the port d is 180 °. Try to be less than the case. As shown in FIG. 12, the rotation speed of the valve body 32h of the four-way valve 32 is made slower than that at the time of switching the normal flow path, and the valve body position is rotated to the position of A °. Thus, it is possible to suppress an extreme fluctuation per hour of the flow rate to the d port side of the four-way valve 32. As a result, the low-temperature water remaining in the tank upper pipe 43 and the circulating water boiled up by the heat pump unit 60 flow into the hot water hot water side pipe 3 in a short time and rapidly in the hot water hot water side pipe 3. Therefore, it is possible to sufficiently follow the hot water temperature correction control of the hot water supply mixing valve 33, and the hot water temperature fluctuation during use can be suppressed to a very small level. Further, since the switching of the four-way valve 32 takes a long time compared with the case of FIG. 11, the valve body position is A ° and the flow path is narrow and the flow rate per hour is small, but the flow rate necessary for preventing freezing as a whole is sufficient. Can be secured.

  In addition, after the switching operation of the four-way valve 32 for preventing freezing, the four-way valve 32 may be controlled to return to the original position (valve element position 90 °). Moreover, although FIG. 12 described the case where the flow path switching operation during the hot water supply operation is continuously performed, it may be intermittently performed as illustrated in FIG.

  Further, during the hot water supply operation, when the heat pump piping freeze prevention operation is shifted to the freeze prevention operation control of the boiling water circulation passage, as shown in FIG. 13, the valve element position A ° of the four-way valve 32 is changed to the valve element position B °. By rotating the valve body 32h to intermittently in a plurality of times, it is possible to further suppress an extreme flow rate fluctuation in the circulating flow rate of the d port of the four-way valve 32. As a result, the flow rate of the low-temperature water remaining in the tank upper pipe 43 and the circulating water boiled up by the heat pump unit 60 from the start of flowing into the hot water supply side pipe 3 until the end of the flow rapidly increases. Since there is no change, it is possible to suppress a rapid hot water temperature fluctuation in the hot water supply hot water side pipe 3 and to sufficiently follow the hot water temperature correction control of the hot water supply mixing valve 33. Hot water temperature fluctuations can be kept extremely small.

  The rotation of the valve body 32h of the four-way valve 32 may be changed according to the hot water supply flow rate during the hot water supply operation. 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 set to 60 seconds, and when the hot water supply flow rate is 5 liters / minute, the rotation time of the valve body 32h is set to 60 seconds. It may be 90 seconds. This is so that the ratio of hot water flowing from the heat pump unit 60 side to the entire hot water supply flow rate via the tank upper pipe 43 does not greatly change between when the hot water flow rate is small and when it is high (when the hot water flow rate is low, This is because the amount of hot water flowing from the tank upper pipe 43 side is not so large as to be dominant, and the temperature fluctuation of the hot water flowing in the hot water hot water side pipe 3 is suppressed to stabilize the hot water temperature.

  Furthermore, as shown in FIG. 10, the four-way valve 32 has an opening region where the flow rate increases extremely depending on the rotational position of the valve body 32h 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 opening degree region where the flow rate increases extremely is small (for example, 5 °), and the opening region where the flow rate does not change is large. (For example, 20 °) may be set. 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.

  Further, the number of intermittent operations may be set variably using the flow rate characteristic of the rotation position of the valve body 32h of the four-way valve 32. When there is an opening region where the flow rate increases extremely and an opening region where the flow rate does not change extremely, the operation from the start to the end of switching is divided into a plurality of regions as shown in FIG. The region until the flow rate fluctuation occurs is the first region (for example, 90 ° to B °), and the valve body 32h is operated by one operation (for example, 20 °). )stand by. Next, a region where extreme flow rate fluctuations occur from the end point of the first region (here, B °) is defined as a second region (for example, from B ° to A ° and up to B °), which is smaller than the first region. The operation is intermittently performed at a degree (for example, 10 °) in a plurality of times, and after the operation, each device waits for a certain time (for example, 3 seconds). Next, the third region (here, B ° to 90 °) is defined as the third region (here, B ° to 90 °) from the end point of the second region (here, B °) to the opening degree until the switching is completed. Switching to the end point of the third region (here 90 °) is performed by one operation (here 20 °). Thereby, the temperature fluctuation of the hot water flowing through the hot water supply side pipe 3 can be further suppressed by finely operating only the region where the temperature fluctuation influence during hot water supply due to the rotation of the four-way valve 32 is large. In addition, 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.

DESCRIPTION OF SYMBOLS 1 Hot water storage unit 2 Water supply piping 3 Hot water supply side piping 4 Hot water supply side piping 5 Hot water supply piping 6 Hot water supply temperature thermistor 10 Hot water storage tank 21 Circulation pump 22 Bath side heat exchanger 31 Three-way valve 32 Four-way valve (channel switching means)
32h Valve body 33 Hot-water supply mixing valve 40 Tank lower pipe 41 Heat pump inlet pipe 42 Heat pump outlet pipe 43 Tank upper pipe 44 Tank return pipe 47 Bypass pipe 60 Heat pump unit 62 Heat exchanger 70 for heating 70 Controller

Claims (7)

A hot water storage tank for storing hot water,
A water supply channel for supplying water to the hot water storage tank;
A boiling heat exchanger that heats the water in the hot water storage tank using predetermined heating means to form high-temperature water;
One end is connected to the upper part of the hot water storage tank, and the boiling water circulation flow path is connected to the first lower part of the hot water storage tank via the flow path switching means and the heating heat exchanger for heating.
A circulation pump installed between the boiling heat exchanger and the first lower part of the hot water storage tank in the boiling water circulation channel;
A lower return flow path connecting the flow path switching means and the second lower portion of the hot water storage tank;
The flow path switching means includes a first flow path configuration in which the boiling heat exchanger and the upper part of the hot water storage tank communicate with each other via the boiling water circulation flow path, the boiling heat exchanger, and the lower part. A second flow path configuration in which the return flow path communicates with the boiling water circulation flow path by means of a built-in valve body,
A mixed hot water side flow path branched from between the connection between the flow path switching means in the boiling water circulation flow path and the upper portion of the hot water storage tank, and connected to the hot water mixing means;
A mixed water side channel branched from the water supply channel and connected to the hot water mixing means;
A hot water supply passage connected from the hot water mixing means to an external faucet;
A hot water supply control means for controlling the hot water mixing means to perform a hot water supply operation of mixing hot water of the mixed hot water side flow path and the hot water of the mixed water side flow path and supplying hot water of a predetermined temperature to the external faucet;
During the freeze prevention operation of the boiling water circulation flow path, the flow of the valve body from the rotation start position that forms the second flow path configuration to a position before the rotation end position that forms the first flow path configuration. A control means for preventing freezing operation that controls the flow path switching means so as to rotate to a flow rate regulating position that is regulated so that the flow rate of hot water flowing through the valve body in the path switching means is reduced;
With
When the freeze prevention operation is performed during the execution of the hot water supply operation, the control unit during the prevention of freezing causes the valve body to be more than the case where the freeze prevention operation is performed during the non-execution of the hot water supply operation. A hot water storage type hot water heater comprising a control means for prolonging a time required for rotating between a start position and the flow rate regulating position. The control means includes
During the freeze prevention operation of the boiling water circulation flow path,
Hot water flowing through the valve body in the flow path switching means from a rotation start position that forms the second flow path configuration to a position before the rotation end position that forms the first flow path configuration. So as to rotate to a flow rate regulating position where the flow rate is regulated to be reduced, and then return the valve body to the rotation start position forming the second flow path configuration,
The hot water storage type hot water supply device according to claim 1, wherein the flow path switching means is controlled. The control means is only during execution of the hot water supply operation.
During the freeze prevention operation of the boiling water circulation flow path,
Hot water flowing through the valve body in the flow path switching means from a rotation start position that forms the second flow path configuration to a position before the rotation end position that forms the first flow path configuration. So as to rotate to a flow rate regulating position where the flow rate is regulated to be reduced, and then return the valve body to the rotation start position forming the second flow path configuration,
The hot water storage type hot water supply device according to claim 1, wherein the flow path switching means is controlled. When the control means performs the freeze prevention operation during execution of the hot water supply operation,
The hot water storage according to any one of claims 1 to 3, wherein the valve body in the flow path switching unit is rotated intermittently in a plurality of times from the start position to the flow rate restriction position. Type water heater. When the control means rotates the valve body in the flow path switching means intermittently divided into a plurality of times,
The hot water storage type hot water heater according to claim 4, wherein a rotation width per rotation is variably set according to a position of the valve body. The control means, depending on the amount of hot water supply of the hot water supply operation,
The hot water storage type hot water supply apparatus according to any one of claims 1 to 5, wherein a time required to rotate the valve body from the start position to the flow rate restriction position is variably set. When the control means rotates the valve body in the flow path switching means intermittently divided into a plurality of times,
The rotation width per turn so that the amount of change in the ratio is constant according to the ratio of the amount of hot water flowing from the flow path switching means to the upper part of the hot water storage tank and the flow rate of hot water flowing to the second lower part. The hot water storage type water heater according to claim 4, wherein the hot water storage type water heater is set variably.

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