JP2011153774A - Hot water storage type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize pressure loss in a hot water/water mixing means, in a storage type hot water supply device including a hot water storage tank 1 connected to a water supply passage 4 at its bottom section and with a hot water tapping passage 5 at its top section, a tank water circulation passage 2 for circulating tank water from the bottom section to the top section of the hot water storage tank, and a heating device 3 for heating the tank water flowing to the tank water circulation passage, and further including the hot water/water mixing means 7 for controlling a mixing ratio of warm water tapped from the hot water storage tank through the hot water tapping passage and cold water supplied through a branched water supply passage 4c branched from the water supply passage 4. <P>SOLUTION: The hot water/water mixing means 7 is composed of a first flow control valve 71 disposed in the hot water tapping passage 5, and a second flow control valve 72 disposed in the branched water supply passage 4c. Pipe conduit resistance of a part of the hot water tapping passage from the first flow control valve 71 to a joining section of the hot water tapping passage 5 and the branched water supply passage 4c is equal to that of a part of the branched water supply passage from the second flow control valve to the joining section. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hot water storage type hot water supply apparatus including a hot water storage tank having a water supply channel connected to the bottom and a hot water supply channel connected to the top.

  The hot water storage type hot water supply apparatus includes a tank water circulation path that circulates tank water from the bottom to the top of the hot water storage tank, and a heating device such as a heat pump that heats the tank water flowing in the tank water circulation path. Then, by adjusting the mixing ratio of the hot water discharged from the hot water storage tank through the hot water supply channel and the cold water supplied through the branched water supply channel branched from the water supply channel, the hot water at the set temperature is supplied. It is supplied to the terminal.

  Conventionally, the hot / cold water mixing means is constituted by a hot / cold water mixing valve composed of an electric three-way valve provided at the junction of the outlet hot water channel and the branch water supply channel (see, for example, Patent Document 1). This hot and cold water mixing valve is arranged in the outer casing that houses the hot water storage tank. It is necessary to reduce the size of the mixing valve. However, when the hot and cold water mixing valve is downsized in this way, the passage portion in the valve becomes narrow and pressure loss increases, making it difficult to secure a sufficient amount of hot water to the hot water supply terminal.

JP 2007-187388 A

  This invention makes it the subject to provide the hot water storage type hot-water supply apparatus which enabled the pressure loss in a hot-water mixing means to be made as small as possible in view of the above point.

  In order to solve the above problems, the present invention comprises a hot water storage tank having a water supply channel connected to the bottom and a hot water supply channel connected to the top, a tank water circulation channel for circulating tank water from the bottom to the top of the hot water tank, A hot water storage type hot water supply device comprising a heating device for heating the tank water flowing in the tank water circulation path, and supplied via hot water discharged from the hot water storage tank via the hot water supply path and a branched water supply path branched from the water supply path Provided with hot water mixing means for adjusting the mixing ratio with cold water so that hot water at a set temperature is supplied to the hot water supply terminal, the hot water mixing means is a first flow rate adjusting valve interposed in the hot water outlet And a second flow rate control valve interposed in the branch water supply channel, the pipe resistance of the portion of the hot water discharge channel from the first flow rate control valve to the junction of the hot water supply channel and the branch water supply channel, and the second flow rate From the control valve to the hot water outlet and the branch water supply A pipeline resistance of the portion of the branch water supply path to flow portion is characterized in that set to be equal.

  According to the present invention, since the hot and cold mixing means is composed of the first and second flow rate control valves, the flow rate control valves are distributed in the upper and lower empty spaces in the outer casing for storing the hot water storage tank. Can be arranged. Therefore, it is possible to avoid an increase in the size of the outer casing without particularly downsizing each flow control valve. Therefore, the pressure loss in each flow rate control valve can be made as small as possible, and the amount of hot water supplied to the hot water supply terminal can be sufficiently secured.

  By the way, the pipe resistance of the portion of the hot water outlet from the first flow rate control valve to the junction of the outlet hot water channel and the branch water supply channel, and the branch water supply from the second flow rate control valve to the junction of the hot water outlet and the branch water supply channel. If the pipe resistance at the portion of the road is different, when the amount of hot water supply is changed, the ratio of the amount of hot water and the amount of cold water supplied to the junction is changed due to the difference in pipe resistance. Therefore, each time the hot water supply amount changes, the flow rate adjusting operation by each flow rate adjusting valve is performed. On the other hand, in this invention, even if the amount of hot water supply changes, the ratio of the amount of hot water supplied to a joining part and the amount of cold water does not change. Therefore, even if the hot water supply amount changes, the flow rate adjustment operation by each flow rate adjustment valve is not performed, the operation frequency of each flow rate adjustment valve is reduced, and durability is improved.

  In the present invention, a hot water outlet for connecting the hot water outlet is opened on the end plate at the top of the hot water storage tank, and the first flow rate control valve is interposed at the upstream end of the hot water outlet and is directly connected to the hot water outlet. It is desirable. According to this, freezing at the first flow rate control valve is prevented by heat transfer from the hot water storage tank, and the freeze prevention means for the first flow control valve becomes unnecessary, and the hot water outlet and the first flow rate control valve are installed. The connecting pipe to be connected becomes unnecessary, and the cost can be reduced.

  Further, the end plate is generally formed in a hemispherical shape. In this case, it is possible to open a hot water outlet at a lower portion than the highest portion of the end plate and directly connect the first flow rate control valve to the hot water outlet. desirable. According to this, the first flow rate control valve can be disposed in a space efficient space space in the upper empty space in the outer casing (a space formed between the ceiling portion of the outer casing and the end plate), and the height dimension of the outer casing is increased. You can avoid that.

Explanatory drawing which shows the structure of the hot water storage type hot water supply apparatus of embodiment of this invention. Sectional drawing of the top part of the hot water storage tank which is a component of the hot water storage type hot water supply apparatus of embodiment. The perspective view seen from diagonally upward of the hot water storage tank of FIG.

  FIG. 1 shows a hot water storage type hot water supply apparatus according to an embodiment of the present invention. This hot water storage type hot water supply apparatus heats a hot water storage tank 1, a tank water circulation path 2 that circulates tank water (water in the hot water storage tank 1) from the bottom to the top of the hot water storage tank 1, and tank water that flows through the tank water circulation path 2. And a heat pump unit 3 as a heating device.

  The hot water storage tank 1 is a tank having a longitudinal capacity of, for example, 50 L in the vertical direction. A water supply channel 4 is connected to the bottom of the hot water storage tank 1, and a hot water supply channel 5 is connected to the top. Cold water from the water pipe 4a is supplied to the water supply path 4 via the pressure reducing valve 4b. Further, a branch water supply path 4c branched from the portion of the water supply path 4 on the downstream side of the pressure reducing valve 4b is provided. The branch water supply path 4c and the hot water supply path 5 are connected to a hot water supply terminal 6a such as a hot water tap. 6 is joined to and connected to the upstream end. Then, the mixing ratio between the hot water discharged from the hot water storage tank 1 through the hot water supply passage 5 and the cold water supplied through the branch water supply passage 4c is adjusted by the hot water mixing means 7 described later, so that the hot water at the set temperature is supplied. It is supplied to the terminal 6a.

  The hot water supply passage 6 is provided with a bypass valve 6b, and in parallel with the bypass valve 6b, a hot water supply heat source device 8 using a burner (not shown) as a heating source is connected. And when the temperature of the hot water discharged to the hot water supply channel 5 becomes lower than the set temperature, the bypass valve 6b is closed, the hot water supply heat source unit 8 is operated, and the hot water supply heat source unit 8 heats the water to the set temperature. Like to do.

  The heat pump unit 3 is a publicly known unit configured with a closed circuit that returns the refrigerant from the evaporator 31 to the evaporator 31 via the compressor 32, the radiator 33, and the expansion valve 34. The evaporator 31 is provided with a fan 31a, and the refrigerant absorbs heat from the atmosphere blown by the fan 31a and evaporates. The evaporated refrigerant is compressed by the compressor 32 to become high temperature and high pressure, radiated by the radiator 33, depressurized by the expansion valve 34, and returned to the evaporator 31.

  The tank water circulation path 2 is configured to circulate tank water from the bottom to the top of the hot water storage tank 1 via the radiator 33 of the heat pump unit 3, and is provided in the tank water circulation path 2 on the heat pump unit 3 side. A circulation pump 2a is provided. When the circulation pump 2 a is operated, low-temperature tank water is supplied to the radiator 33 from the bottom of the hot water storage tank 1, and the tank water is heated by heat exchange with the refrigerant in the radiator 33 and returned to the top of the hot water storage tank 1. It is. Circulation pump 2a and heat pump unit 3 are activated when the temperature detected by a temperature sensor (not shown) that detects the temperature of the tank water in the upper part of hot water storage tank 1 falls below a predetermined temperature.

  The hot water storage tank 1 is accommodated in the outer casing 12 in a state of being covered with a heat insulating material 11 (see FIGS. 2 and 3). On the lateral side surface of the outer casing 12, a water supply connection port 12 a that connects the water pipe 4 a to the water supply channel 4, and a hot water supply connection port 12 b that connects a hot water supply pipe 6 c that becomes the hot water supply channel 6 outside the outer casing 12, A forward connection port 12c and a return connection port 12d for the heat source device are provided to connect the inflow side piping 8a and the outflow side piping 8b of the hot water supply heat source device 8 to the upstream and downstream hot water supply passages 6b of the bypass valve 6b, respectively. It has been. Further, on the other side surface of the outer casing 12 in the lateral direction, a forward connection port 12e for the circulation path that connects the forward pipe 2b and the return pipe 2c to the heat pump unit 3, which is the tank water circulation path 2 outside the outer casing 12, respectively. And a return connection port 12f.

The hot water / mixing means 7 is composed of a first flow rate adjusting valve 71 provided in the tap water passage 5 and a second flow rate adjusting valve 72 provided in the branch water supply passage 4c. Further, a first temperature sensor 73 ₁ which detects the temperature of hot water flowing through the tapping passage 5, _two second temperature sensor 73 for detecting the temperature of the cold water flowing through the branch water supply passage 4c, the temperature of the hot water flowing through the hot water supply passage 6 are provided and a third temperature sensor 73 ₃ which detects. Then, the first and second respective flow rate control valves 71 and 72 to feed forward control based on the first and _one second the temperature sensors 73, 73 ₂ of the detected temperature, the third temperature sensor 73 _third detection The flow rate control valves 71 and 72 are feedback-controlled so that the temperature becomes the set temperature, and the mixing ratio of hot water and cold water is automatically adjusted so that hot water at the set temperature is supplied to the hot water supply terminal 6a.

  If the hot and cold mixing means 7 is composed of the first and second flow rate adjusting valves 71 and 72 as described above, the both flow rate adjusting valves 71 are provided in the upper and lower empty spaces in the outer casing 12 for storing the hot water storage tank 1. , 72 can be distributed. Therefore, it is possible to avoid an increase in the size of the outer casing 12 without particularly reducing the size of each of the flow rate control valves 71 and 72. Therefore, the pressure loss at each of the flow rate control valves 71 and 72 can be made as small as possible to ensure a sufficient amount of hot water to the hot water supply terminal 6a.

  By the way, the pipe resistance of the portion of the hot water supply path 5 from the first flow rate control valve 71 to the junction (the upstream end of the hot water supply path 6) between the hot water supply path 5 and the branch water supply path 4c, and the hot water supply from the second flow rate control valve 72. If the pipe resistance of the branch water supply path 4c up to the upstream end of the path 6 is different, when the amount of hot water supply is changed by adjusting the opening of the hot water tap as the hot water supply terminal 6a, the hot water supply is caused by the difference in the pipe resistance. The ratio between the amount of hot water supplied to the path 6 and the amount of cold water will change. Therefore, every time the hot water supply amount changes, the flow rate adjusting operation by the flow rate adjusting valves 71 and 72 is performed. As a result, the operation frequency of each flow control valve 71, 72 increases, and the durability is adversely affected. Furthermore, when the hot water supply amount changes, the hot water supply temperature deviates from the set temperature until the flow rate adjustment operation by the flow rate adjustment valves 71 and 72 is completed, which makes the user feel uncomfortable.

  Therefore, in the present embodiment, the pipe resistance of the portion of the hot water discharge path 5 from the first flow rate adjustment valve 71 to the upstream end of the hot water supply path 6 and the branched water supply from the second flow rate adjustment valve 72 to the upstream end of the hot water supply path 6. The pipe line resistance of the part of the path 4c is made equal. According to this, even if the amount of hot water supply changes, the ratio of the amount of hot water supplied to the hot water supply passage 6 and the amount of cold water does not change. Therefore, even if the amount of hot water supply changes, the flow rate adjustment operation by each flow rate adjustment valve 71, 72 is not performed, the operation frequency of each flow rate adjustment valve 71, 72 decreases, and durability improves. Furthermore, even if the hot water supply amount changes, the hot water supply temperature does not change, and the user does not feel uncomfortable.

  In FIG. 1, the length of the portion of the hot water supply passage 5 from the first flow rate adjustment valve 71 to the upstream end of the hot water supply passage 6 and the portion of the branch water supply passage 4 c from the second flow rate adjustment valve 72 to the upstream end of the hot water supply passage 6 are shown. Even if they are not equal, the pipe resistances can be made equal by changing the pipe diameters and the degree of bending of the hot water supply path 5 and the branch water supply path 4c.

  2 and 3, the top of hot water storage tank 1 is formed of a hemispherical end plate 1a. In the end plate 1a, a return port 1b for connecting the tank water circulation path 2 is located at the highest portion of the end plate 1a, and at the lower portion of the return port 1b, a tap water path 5 is connected. A hot spring outlet 1c is established. The first flow rate control valve 71 is directly connected to the hot water outlet 1 c in a state of being interposed at the upstream end of the hot water flow path 5. That is, the inflow port 71a of the first flow rate control valve 71 is directly connected to the hot water outlet 1c.

  If the first flow rate control valve 71 is directly connected to the hot water outlet 1c in this way, freezing at the first flow rate control valve 71 is prevented by heat transfer from the hot water storage tank 1, and freezing prevention for the first flow rate control valve 71 is achieved. This eliminates the need for a means and eliminates the need for a connecting pipe for connecting the hot water outlet 1c and the first flow rate adjusting valve 71, thereby reducing the cost. Furthermore, since the tap 1c is opened at a relatively low portion of the end plate 1a, the empty space in the upper part of the outer casing 12 (the space generated between the ceiling portion of the outer casing 12 and the end plate 1a) is efficiently space-efficient. 1 The flow control valve 71 can be arrange | positioned and it can avoid that the height dimension of the exterior casing 12 becomes large.

  In addition, the hot water storage type hot water supply apparatus is a pressure relief that opens when the pressure in the hot water storage tank 1 exceeds a predetermined value in order to prevent bubbles from being stored in the hot water storage tank 1 and excessively increasing the pressure. A valve 9 is provided. Conventionally, the pressure relief valve is generally connected to the hot water discharge path 5. However, when the internal pressure of the hot water discharge path 5 suddenly increases due to a water hammer phenomenon that occurs when hot water supply is stopped, the pressure relief valve is The valve opens and the hot water is drained wastefully.

  Therefore, in this embodiment, the pressure relief valve 9 is connected to the tank water circulation path 2 at the end of the hot water storage tank 1 on the top side. The pressure relief valve 9 is provided with a lever 9a for manually opening the valve, and functions as a valve for opening the hot water storage tank 1 to the atmosphere when water is poured into the hot water storage tank 1 or drained. A drain hose 9 b is connected to the outlet of the pressure relief valve 9.

  If the pressure relief valve 9 is connected to the tank water circulation path 2 in this way, the hot water storage tank 1 functions as a buffer even if the internal pressure of the hot water discharge path 5 suddenly increases due to a water hammer phenomenon when hot water supply is stopped. Up to the valve 9, the influence of the rapid increase in the internal pressure of the hot water outlet 5 becomes difficult to reach. Therefore, even if the water hammer phenomenon occurs, the pressure relief valve 9 does not open, and it is possible to prevent the warm water from being drained wastefully.

  Moreover, in this embodiment, since the return port 1b is opened in the highest part of the end plate 1a as described above, and the hot water outlet 1c is opened in a lower part, the bubbles in the hot water storage tank 1 are at the highest point. It is guided to the pressure relief valve 9 from the positioned return port 1b, and air bubbles can be prevented from entering the hot water outlet 5.

  Further, the circulation pump 2a and the heat pump unit 3 may be operated during hot water supply. In this case, when the high temperature water flowing into the hot water storage tank 1 from the return port 1b flows directly to the hot water outlet 1c, the temperature of the hot water discharged from the hot water channel 5 rises rapidly, and the first flow rate control valve 71 is controlled. The hot water temperature will overshoot due to the response delay. In particular, when the hot water supply heat source unit 8 is operating, the amount of overshoot increases and hot water is supplied.

  On the other hand, in this embodiment, even if high temperature water flows into the hot water storage tank 1 from the return port 1b, it becomes difficult for high temperature water to flow directly into the hot water outlet 1c lower than the return port 1b. The temperature of the heated water rises relatively slowly. Therefore, the control of the hot water flow rate by the first flow rate control valve 71 is in time, the hot water temperature overshoot is suppressed, and no hot water is supplied.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to this. For example, the hot water storage type hot water supply apparatus of the above embodiment is of a hybrid type provided with the hot water supply heat source unit 8 in addition to the heat pump unit 3, but the hot water supply heat source unit 8 may be omitted. Further, as a heating device for heating the tank water flowing in the tank water circulation path 2, a device other than the heat pump unit 3 such as a solar panel or a fuel cell can be used. In the above embodiment, the pressure relief valve 9 is connected to the tank water circulation path 2, but it is also possible to directly attach the pressure relief valve to the top of the hot water storage tank 1.

  DESCRIPTION OF SYMBOLS 1 ... Hot water storage tank, 1a ... End plate, 1c ... Hot water outlet, 2 ... Tank water circulation path, 3 ... Heat pump unit (heating device), 4 ... Water supply path, 4c ... Branch water supply path, 5 ... Hot water supply path, 6 ... Hot water supply path, 6a ... Hot water supply terminal, 7 ... Hot water mixing means, 71 ... First flow rate adjustment valve, 72 ... Second flow rate adjustment valve.

Claims (3)

A hot water storage tank having a water supply channel connected to the bottom and a hot water supply channel connected to the top, a tank water circuit that circulates tank water from the bottom to the top of the hot water tank, and heating that heats the tank water flowing through the tank water circuit A hot water storage type hot water supply device comprising a device, adjusting a mixing ratio of hot water discharged from a hot water storage tank through a hot water supply channel and cold water supplied through a branch water supply channel branched from the water supply channel, In what has hot water mixing means to allow hot water of a set temperature to be supplied to the hot water supply terminal,
The hot water mixing means is composed of a first flow rate control valve interposed in the outlet channel and a second flow rate control valve interposed in the branch water supply channel,
The pipe resistance of the portion of the hot water path from the first flow rate control valve to the junction of the hot water channel and the branch water supply channel, and the branch water channel of the branch water channel from the second flow rate control valve to the junction of the hot water channel and the branch water channel A hot water storage type hot water supply device characterized in that the pipe line resistance of the portion is equal.   A hot water outlet that connects the hot water passage is opened on the end plate of the hot water storage tank, and the first flow rate control valve is interposed at the upstream end of the hot water passage and is directly connected to the hot water outlet. The hot water storage type hot water supply apparatus according to claim 1.   The hot water storage hot water supply apparatus according to claim 2, wherein the end plate is formed in a hemispherical shape, and the hot water outlet is opened at a lower portion than the highest portion of the end plate.

Images