JP5178142B2 - Hot water storage water heater - Google Patents

Description

  The present invention boils low-temperature water taken from the lower part of a hot water storage tank into hot water with a boiling heat exchanger, while hot water stored in the hot water storage tank is used as a heat source for hot water used in a bathtub or hot water heating equipment. The present invention relates to a hot water storage type water heater that boils water.

  Hot water boiled by the heat source machine is temporarily stored in a hot water storage tank, and when the user opens the hot water tap provided at the end of the hot water pipe connected to the hot water storage tank, the hot water in the hot water storage tank is left as it is or with water. In the hot water storage water heaters that are configured to be discharged, the hot water in the hot water storage tank can be used as a heat source for boiling the hot water used in bathtubs and hot water heating facilities. Has been.

  In such a hot water storage type hot water heater, a boiling circulation line for boiling low-temperature water taken from the lower part of the hot water storage tank into hot water by a boiling heat exchanger and returning it to the hot water storage tank from the upper part of the hot water storage tank, There is provided a heat source circulation pipe that uses hot water taken from the upper part of the hot water storage tank as a heat source in the secondary usage side heat exchanger and then returns the hot water from the lower part of the hot water storage tank to the hot water storage tank. Conventionally, one circulation pump has been arranged in each circulation pipe. However, in the hot water storage type water heater (hot water heater) described in Patent Document 1, hot water in each circulation pipe is provided by one circulation pump. Allows circulation.

  In the hot water storage type water heater described in Patent Document 1, a first three-way valve is provided on the lower side of the hot water storage tank (hot water tank) in the boiling circulation line, and the boiling three-way valve is used for the boiling circulation line. The second three-way valve is provided on the downstream side of the boiling heat exchanger (hot water supply heat exchanger), and the second three-way valve is connected to the heat source from the boiling circulation line. The circulation line for use is branched. And by arrange | positioning a circulation pump between the 1st three-way valve and the heat exchanger for boiling, the circulation of the hot water in each circulation line is enabled by one circulation pump.

JP 2004-218907 A

  However, in the hot water storage type water heater described in Patent Document 1, when a secondary use operation (tub water boiling operation) is performed in which hot water taken from the upper part of the hot water storage tank is used as a heat source in the secondary usage side heat exchanger In addition, after the hot water taken from the upper part of the hot water storage tank exchanges heat with the spent water in the secondary use side heat exchanger (use side heat exchanger), a boiling heat exchanger (hot water supply heat exchanger) is installed. After that, since it is returned to the lower part of the hot water storage tank, the length of the piping in the heat source circulation line tends to be long. An increase in the pipe length in the heat source circulation line leads to an increase in heat dissipation loss in the heat source circulation line, and an increase in heat dissipation loss leads to a decrease in utilization efficiency of hot water.

  The present invention has been made in view of the above circumstances, and includes a boiling circulation line and a heat source circulation line, and the circulation of hot water in each circulation line can be performed by a single circulation pump. An object of the present invention is to obtain a hot water storage type water heater that can easily increase the utilization efficiency of hot water.

The hot water storage type water heater of the present invention that achieves the above-mentioned object is for boiling water, in which low-temperature water taken from the lower part of the hot water storage tank is boiled into hot water by a boiling heat exchanger and returned to the hot water storage tank from the upper part of the hot water storage tank. A hot water storage type water heater having a circulation line and a heat source circulation line for returning hot water taken from the upper part of the hot water storage tank to the hot water storage tank from the lower part of the hot water storage tank after being used as a heat source in the secondary use side heat exchanger The boiling circulation line and the heat source circulation line include a first shared line part whose one end is connected to the lower part of the hot water storage tank, a first upstream line of the boiling heat exchanger, and a first one. A second shared pipe section provided in a region located on the downstream side of each of the shared pipe section and the secondary usage side heat exchanger, and a secondary usage side heat exchanger on the downstream side of the boiling heat exchanger A third joint provided in an area located upstream of the first end and connected at one end to the upper part of the hot water storage tank. A first control valve that joins the boiling circulation pipe and the heat source circulation pipe, a circulation pump, and a heat source circulation pipe to the second shared pipeline section. And a second control valve that branches from the circulation pipe is arranged in this order from the upstream side of the second shared pipe section, and the second control valve The amount of flow down to the heat source circulation pipe can be adjusted individually, and the secondary use operation using hot water taken from the upper part of the hot water storage tank as a heat source in the secondary use side heat exchanger, and during the secondary use operation After a portion of the hot water whose temperature has been reduced due to heat removal from the secondary use side heat exchanger flows from the second shared pipeline into the boiling circuit, A chasing operation for returning to the heat source circuit from the downstream side can be performed simultaneously .

  In the hot water storage type hot water supply apparatus of the present invention, the second shared pipeline section is provided in a region located upstream of the boiling heat exchanger, and the circulation pump is disposed in the second shared pipeline section. The hot water circulation in each of the boiling circulation line and the heat source circulation line can be performed by one circulation pump. Compared with the hot water supply apparatus described in Patent Document 1 in which the downstream end of the heat source circulation pipe is connected to the hot water storage tank on the downstream side of the boiling heat exchanger (hot water supply heat exchanger), the heat source circulation pipe It is easy to shorten the piping length in the passage, and as a result, it is easy to suppress the heat radiation loss in the circulation pipe for the heat source and increase the utilization efficiency of hot water. Therefore, according to the present invention, it is easy to inexpensively provide a hot water storage type hot water heater that includes a boiling circulation line and a heat source circulation line and has high hot water utilization efficiency.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a hot water storage type water heater of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments described below.

  FIG. 1 is a block diagram schematically showing an example of a hot water storage type water heater. The hot water storage type water heater 70 shown in the figure has a function of boiling low-temperature water such as city water into hot water and supplying it to a desired location, and a function as a heat source of hot water used in a bathtub, hot water heating equipment, etc. The hot water storage type water heater 70 includes a hot water supply unit 1 and a heat pump unit 60. Hereinafter, the components of the hot water storage type hot water heater 70 will be described.

  The hot water supply unit 1 includes a hot water storage tank 10, a water supply pipe 15 connected to the lower part of the hot water storage tank 10 to supply low temperature water such as city water into the hot water storage tank 10, and a heat pump unit 60 from the lower part of the hot water storage tank 10. And a hot water supply pipe 30 which is connected to the upper part of the hot water storage tank 10 and sends hot water in the hot water storage tank 10 to a desired hot water supply destination. . Furthermore, from the upper part of the hot water storage tank 10 to the lower side of the hot water storage tank 10 through the secondary usage side heat exchanger 35 and the heat source circulation line 40 and the heated equipment 80 such as a bathtub or hot water heating equipment to the secondary usage side. A facility-side circulation conduit 50 that returns to the heated facility 80 via the heat exchanger 35 is also included.

The boiling circulation line 20 is a circulation line for boiling low-temperature water taken from the lower part of the hot water storage tank 10 into hot water by the heat pump unit 60 and then returning it to the upper part of the hot water storage tank 10. The boiling circulation pipe 20 includes a first shared pipe section CL ₁ having one end connected to the lower part of the hot water storage tank 10 and a first dedicated pipe connected to the other end of the first shared pipe section CL _1. and the flow path portion 20a, the second dedicated to the second common line portion CL ₂ connected to the downstream end of the first dedicated pipeline section 20a, which is connected to the second downstream end of the common conduit section CL ₂ and the flow path portion 20b, and a third common line portion CL ₃ connecting the upper part of the downstream end and the hot water storage tank 10 of the second dedicated pipeline section 20b.

The second shared pipe section CL ₂ is provided upstream of the heat pump unit 60, and the second shared pipe section CL ₂ includes a boiling circulation pipe 20 and a heat source circulation pipe 40. Are arranged in this order from the upstream side, the first control valve 22 for joining the two, the circulation pump 24, and the second control valve 26 for branching the heat source circulation line 40 from the boiling circulation line 20. . The first control valve 22 has two inlets and one outlet, and the second control valve 26 has one inlet and two outlets. Each of the first control valve 22 and the second control valve 26 is driven by a motor M. The second control valve 26 can arbitrarily change the flow rate at each of the two outlets.

The heat source circulation line 40 uses hot water taken from the upper part of the hot water storage tank 10 as a heat source for heating the used water in the secondary usage side heat exchanger 35 and then returns the hot water from the lower part of the hot water storage tank 10 to the hot water storage tank 10. It is a circulation line. The heat source circulation pipe 40 reaches the first control valve 22 through the third shared pipe section CL ₃ and the third shared pipe section CL ₃ through the secondary use side heat exchanger 35. a first dedicated pipeline section 40a, and the second common line portion CL ₂ above, the second downstream end of the common conduit section CL ₂ (second control valve 26) and the first and the shared line portion CL ₁ a second dedicated pipeline section 40b connecting includes a first and a common conduit portion CL ₁ above.

  The facility-side circulation conduit 50 circulates the used water (water or hot water) taken from the heated facility 80 such as a bathtub or a hot water heating facility after being heated by the secondary usage side heat exchanger 35 and then returned to the heated facility 80. It is a pipeline. The spent water is heated in the secondary use side heat exchanger 35 by using hot water flowing down the heat source circulation pipe 40, specifically, hot water flowing down the first dedicated pipe section 40a as a heat source. . In the illustrated example, the circulation pump 55 is disposed between the heated facility 80 and the secondary usage side heat exchanger 35.

  On the other hand, the heat pump unit 60 is for boiling low-temperature water flowing down the boiling circulation line 20 into hot water. The compressor 61 compresses the refrigerant, the heat exchanger 62 for boiling, the expansion valve 63, and the like. The refrigeration cycle system includes an evaporator 64 and a circulation pipe 65 that connects these in an annular shape. A cooling fan 66 that cools the evaporator 64 is provided in the vicinity of the evaporator 64. Yes. The refrigerant is compressed by the compressor 61 to become high temperature and high pressure, and then radiates heat by the boiling heat exchanger 62, is depressurized by the expansion valve 63, absorbs heat by the evaporator 64, and becomes a gas state. 61 is inhaled.

  A region of the boiling circulation pipe 20, specifically, a region of the second dedicated pipe part 20 b passes through the boiling heat exchanger 62 and flows down the second dedicated pipe part 20 b. The low-temperature water is boiled into hot water by exchanging heat between the condensed refrigerant and the heat exchanger 62 for boiling.

  Although not shown, the hot water storage type hot water heater 70 includes a control unit that controls operations of the first control valve 22, the circulation pump 24, the second control valve 26, the circulation pump 55, and the heat pump unit 60, and the control unit. And an operation unit that is used as an input device for commands and the like. The hot water storage type water heater 70 performs a hot water boiling operation or a secondary usage operation using the hot water in the hot water storage tank as a heat source in accordance with a command or the like input from the operation unit by the user. Hereinafter, each operation will be described with reference to FIG. 2 or FIG.

FIG. 2 is a block diagram showing a flow path of low temperature water or hot water when a boiling operation is performed by the hot water storage type hot water supply device 70. As indicated by an arrow A in the figure, low temperature water or hot water flows down the boiling circulation pipe 20 during the boiling operation. Influx of water from the upper portion of the hot water storage tank 10 to the heat source for the circulation line 40, the flow of hot water from the second common line portion CL ₂ to the second dedicated line portion 40b of the heat source for the circulating pipe 40, and the equipment-side There is no inflow of used water into the circulation line 50. That is, at the time of boiling up operation, the first control valve 22 is communicated with only the first dedicated line portion 20a to the second common line portion CL _2, the second control valve 26 is only the second private line portion 20b first 2 so as to communicate with the shared line portion CL _2, these operations of the first control valve 22 and the second control valve 26 is controlled. Further, the circulation pump 24 and the heat pump unit 60 are respectively operated. Circulation pump 55 is not operated.

The hot water storage tank 10 before the start of the boiling operation is filled with low temperature water such as city water supplied from the water supply pipe 15 or the remaining hot water stays on the upper side and the low temperature supplied from the water supply pipe 15 is reached. Water stays below and is full. When the boiling operation is started, the low-temperature water that has flowed into the first shared pipe section CL ₁ from the lower part of the hot water storage tank 10 is in the first shared pipe section CL ₁ , the first dedicated pipe section 20a, and the second flows into the second dedicated pipeline section 20b sequentially flows down a shared line portion CL _2. Then, after being boiled in hot water by boiling for raising heat exchanger 62 in the process of flowing down the second dedicated pipeline section 20b, through the third common line portion CL ₃ from the second dedicated pipeline section 20b the hot-water It reaches the upper part of the tank 10 and returns to the hot water storage tank 10 from here. A temperature sensor (not shown) is provided on the lower side of the hot water storage tank 10, and when the control unit (not shown) detects that the temperature detected by the temperature sensor exceeds a predetermined temperature, the control unit End boiling operation.

FIG. 3 is a block diagram showing a flow path of hot water and used water when a secondary use operation is performed by the hot water storage type hot water heater 70. As indicated by the arrow B in the figure, during secondary use operation, hot water taken from the upper part of the hot water storage tank 10 flows down the third shared conduit portion CL ₃ and the first dedicated conduit portion 40a sequentially, 1 The used water is heated by the secondary use side heat exchanger 35 in the process of flowing down the dedicated pipe section 40a. The hot water that has been deprived of heat by the secondary-use-side heat exchanger 35 further flows down the first dedicated pipe section 40a and flows from the first control valve 22 into the second shared pipe section CL2, and the _second 2 After flowing down the common pipe section CL ₂ and flowing into the second dedicated pipe section 40 b from the second control valve 26, the hot water storage tank 10 is transferred from the lower part of the hot water storage tank 10 through the first common pipe section CL _1. Returned. Moreover, as shown by the arrow C in the figure, the used water taken from the heated equipment 80 flows down the equipment-side circulation pipe 50, and the heat source circulation pipe 40 (first dedicated pipe section 40a). After being heated by the secondary usage side heat exchanger 35 using hot water flowing down as a heat source, it is returned to the heated facility 80. No inflow of cold water from the lower part of the hot water storage tank 10 to the first common line portion CL _1.

That is, when secondary usage operation, the first control valve 22 is communicated with only the first dedicated line portion 40a to the second common line portion CL _2, the second control valve 26 is only the second private line section 40b so as to communicate with the second common line portion CL _2, these operations of the first control valve 22 and the second control valve 26 is controlled. Further, the circulation pump 24 and the circulation pump 55 are operated. The heat pump unit 60 is not operated.

  A control unit (not shown) that the temperature detected by a temperature sensor (not shown) provided in a predetermined location of the facility-side circulation pipe 50, for example, in the vicinity of the inlet to the heated facility 80, exceeds a predetermined temperature. Is detected, the secondary use operation is terminated. When the secondary use operation is performed, the high temperature hot water stored in the upper part of the hot water storage tank 10 flows into the heat source circulation pipe 40 and is deprived of heat by the secondary use side heat exchanger 35, As a result of returning to the hot water storage tank 10 from the lower part of the hot water storage tank 10, the amount of hot water in the hot water storage tank 10 gradually decreases. Therefore, when the control unit detects that the temperature detected by a temperature sensor (not shown) provided on the upper side of the hot water storage tank 10 is lower than a predetermined temperature, the hot water storage type hot water heater 70 performs the secondary use operation. finish. It is also possible to configure the hot water storage type hot water heater 70 so as to maintain or increase the amount of heat stored in the hot water storage tank 10 by replenishing hot water whose temperature has decreased in the secondary usage operation while continuing the secondary usage operation.

FIG. 4 is a block diagram showing a flow path of hot water and used water when the secondary use operation and the reheating operation are simultaneously performed by the hot water storage type hot water heater 70. When the secondary use operation and the follow-up operation are performed simultaneously, as shown by arrows B and C in the figure, hot water or used water in each of the heat source circulation pipe 40 and the facility-side circulation pipe 50 is used. The circulation form is the same as the circulation form when the secondary use operation is performed independently. On the other hand, in the boiling circulation line 20, as indicated by an arrow D in the figure, a part of the hot water whose temperature has been reduced due to the heat deprived by the secondary use side heat exchanger 35 due to the secondary use operation is obtained. second after the reheating and flows from the common conduit section CL ₂ to the second dedicated pipeline section 20b, the first dedicated line portion of the third common line portion CL heat source circulating passage 40 from the downstream side of the ₃ It is returned to 40a. No inflow of cold water from the lower part of the hot water storage tank 10 to the first common line portion CL ₁ and the first dedicated pipeline section 20a.

That is, when performing secondary usage operation and reheating operation and at the same time, the first control valve 22 is communicated with only the first dedicated line portion 40a to the second common line portion CL _2, the second control valve 26 is 2 One of the second dedicated pipeline section 20b, 40b and to cause the second communication with the common conduit section CL _2, these operations of the first control valve 22 and the second control valve 26 is controlled. Hot water flowing down the first dedicated pipeline section 40a of the heat source circulating passage 40, after the first control valve 22 and flows second shared line portion CL ₂ flows down the second common line portion CL ₂ The second control valve 26 distributes each of the two second dedicated pipe sections 20b and 40b at a predetermined ratio. Then, the second control valve 26 is distributed to the second dedicated pipeline section 20b yu, third downstream shared line portion CL ₃ after being boiled in hot water by boiling for raising the heat exchanger 62 To the first dedicated pipe section 40a of the heat source circulation path 40. Further, the second control valve 26 is distributed to the second dedicated pipeline section 40b water is returned to the hot water storage tank 10 from the lower portion of the hot water storage tank 10 via the first common line portion CL _1.

  When the secondary use operation and the follow-up operation are performed simultaneously, the circulation pump 24, the circulation pump 55, and the heat pump unit 60 are each operated. The amount of hot water flowing from the second control valve 26 to each of the second dedicated pipe sections 20b and 40b takes into account, for example, the required heating capacity in the secondary usage side heat exchanger 35 and the heating capacity of the heat pump unit 60. The rotation speed of the circulation pump 24 is adjusted based on data created in advance, and the distribution ratio of the second control valve 26 is adjusted.

In the hot water storage type hot water heater 70 having the above-described configuration, the second shared pipe section CL ₂ is located in a region located upstream of the boiling heat exchanger 62 and downstream of the secondary usage side heat exchanger 35. Since the circulation pump 24 is provided and disposed here, the circulation pump 24 can circulate hot water in each of the boiling circulation line 20 and the heat source circulation line 40. Since it is not necessary to arrange one circulation pump in each of the boiling circulation line 20 and the heat source circulation line 40, the manufacturing cost can be reduced. Compared with the hot water supply apparatus described in Patent Document 1 in which the downstream end of the heat source circulation pipe is connected to the hot water storage tank on the downstream side of the boiling heat exchanger (hot water supply heat exchanger), the heat source circulation pipe It is easy to shorten the piping length in the path 40, and as a result, it is easy to suppress the heat radiation loss in the heat source circulation pipe 40 and increase the utilization efficiency of hot water. Therefore, in the hot water storage type hot water heater 70, it becomes easy to provide a low-cost hot water utilization efficiency that includes the boiling circulation line 20 and the heat source circulation line 40 and has high utilization efficiency of hot water.

  In addition, when the hot water storage type hot water heater 70 is configured so that hot water whose temperature has decreased in the secondary usage operation can be replenished while the secondary usage operation is continued, the amount of heat stored in the hot water storage tank 10 is reduced. Since it is possible to prevent a drop, it is possible to boil the hot water used in the heated equipment 80 such as a bathtub or hot water heating equipment while ensuring the amount of hot water supplied from the hot water storage tank 10 to a hot water supply destination such as a kitchen or a washroom. As a result, the convenience increases.

  As mentioned above, although the hot water storage type hot water heater of the present invention has been described with reference to the embodiment, the present invention is not limited to the above-described form as described above. For example, the number of secondary usage-side heat exchangers and facility-side circulation pipelines is not limited to one each, and the number of secondary usage-side heat exchangers and facility-side circulation pipelines is not limited to bathtubs or hot water heating. It can be appropriately selected according to the total number of facilities to be heated such as facilities. Moreover, about an equipment side circulation pipeline, it can also be set as arbitrary components other than setting it as an essential component.

  The heat pump unit may be, for example, a unit that pressurizes carbon dioxide, which is a refrigerant, to a pressure higher than the critical pressure, or may be a unit that pressurizes the refrigerant to a pressure lower than the critical pressure. As the refrigerant, in addition to carbon dioxide, fluorocarbon gas, ammonia gas, or the like may be used. The hot water storage type hot water heater of the present invention can be variously modified, modified, combined, etc. in addition to those described above.

  Since the hot water storage type hot water supply apparatus of the present invention can also perform secondary use of hot water, in order to save energy in homes and offices equipped with a bathtub, hot water heating equipment, etc. in addition to hot water supply equipment. It is suitable.

It is a block diagram which shows roughly an example of the hot water storage type water heater of this invention. It is a block diagram which shows the flow path of the low temperature water or hot water when a boiling operation is performed by the hot water storage type hot water supply device shown in FIG. It is a block diagram which shows the flow path of the hot water when the secondary use driving | operation is performed with the hot water storage type water heater shown in FIG. It is a block diagram which shows the flow path of hot water and used water when a secondary use driving | operation and a chasing operation are performed simultaneously with the hot water storage type water heater shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot water supply unit 10 Hot water storage tank 20 Circulation line for boiling 20a 1st exclusive pipe part 20b 2nd exclusive pipe part 22 1st control valve 24 Circulation pump 26 2nd control valve 35 Secondary use side heat exchanger 40 Heat source Circulation pipeline 40a First dedicated pipeline section 40b Second dedicated pipeline section 50 Equipment-side circulation pipeline 55 Circulation pump 60 Heat pump unit 62 Boiling heat exchanger 70 Hot water storage hot water supply CL ₁ First shared pipeline section CL ₂ 2nd shared pipeline section CL ₃ 3rd shared pipeline section

Claims (2)

Boiling low temperature water taken from the bottom of the hot water tank is boiled into hot water by a boiling heat exchanger and returned to the hot water tank from the upper part of the hot water tank, and hot water taken from the upper part of the hot water tank is A hot water storage type hot water heater comprising a heat source circulation pipe that is used as a heat source in a secondary use side heat exchanger and then returned from the lower part of the hot water storage tank to the hot water storage tank,
The boiling circulation line and the heat source circulation line include a first shared line part having one end connected to a lower portion of the hot water storage tank, an upstream side of the boiling heat exchanger, and the first line. A second shared pipeline section provided in a region located on the downstream side of each of the first shared pipeline section and the secondary usage side heat exchanger; and a downstream side of the boiling heat exchanger and the secondary usage A third shared conduit portion provided in a region located on the upstream side of the side heat exchanger and having one end connected to an upper portion of the hot water storage tank;
In the second shared pipeline section, a first control valve that joins the boiling circulation pipeline and the heat source circulation pipeline, a circulation pump, and the heating source circulation pipeline to the circulation for boiling. A second control valve for branching from the pipeline is arranged in this order from the upstream side in the second shared pipeline section ,
The second control valve can individually adjust the amount of flow down to the boiling circulation line and the amount of flow down to the heat source circulation line,
Secondary usage operation using hot water taken from the upper part of the hot water storage tank as a heat source in the secondary usage side heat exchanger, and the temperature is lowered due to heat being taken away by the secondary usage side heat exchanger during the secondary usage operation A part of the hot water that has flowed from the second shared pipe part into the boiling circulation path and chased, and then returned to the heat source circulation path from the downstream side of the third shared pipe part Can be done at the same time,
A hot water storage water heater characterized by that. The facility-side circulation pipeline according to claim 1, further comprising a facility-side circulation line that boils spent water taken from other facilities using hot water and returns the spent water to the facility using the secondary-use-side heat exchanger. Hot water storage water heater.

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