JP2019158211A - Hot water supply unit and hot water supply system - Google Patents

Abstract

To provide a compact hot water supply unit with a simple structure, and a hot water supply system, which allow stable temperature adjustment to be executed from an initial hot water supply stage.SOLUTION: A low temperature side pipe 309 is connected to a lower part of a hot water storage tank 307. The low temperature side pipe 309 is a pipe for sending low temperature water to a heat source 305. A high temperature side pipe 311 is connected to a higher part of the hot water storage tank 307. The high temperature side pipe 311 is a pipe for returning high temperature water from the heat source 5 to the hot water storage tank 307. In a hot water supply unit 403, the high temperature side pipe 311 and a hot water supply pipe 313 are arranged close to each other. By executing heat exchange between hot water in the high temperature side pipe 311 and hot water in the hot water supply pipe 313, the hot water in the hot water supply pipe 313 rises in temperature by the hot water in the high temperature side pipe 311 so as to suppress a decrease in temperature of the hot water in the hot water supply pipe 313.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hot water supply unit and a hot water supply system using heat from a heat source.

  Conventionally, for example, a cogeneration system that effectively uses heat generated by a generator or the like has been proposed. FIG. 4 is a diagram showing an overall configuration of a conventional cogeneration system 1. As shown in the figure, the cogeneration system 1 includes a power generation device 100 that generates electricity and heat, a hot water storage device 200 (hot water storage tank 307) that stores hot water, a hot water storage device 200 (hot water storage tank 307), and the power generation device 100. A heat recovery circuit 7 is provided for recovering the exhaust heat of the power generation apparatus 100 by circulating hot water between them through the heat exchanger 6.

  The power generation device 100 mainly includes a fuel cell 11, a hydrogen generator 2, an air supply device 3, a cooling water circulation circuit 4, a cooling water pump 5, a heat exchanger 6, a heat recovery circulation circuit 7, a heat recovery circulation pump 8, an electric power. A conversion device 9, a control device 10, a cooling temperature sensor 13, a surplus power consumption heater 14, and the like are provided.

  The fuel cell 11 generates electric power and heat simultaneously by electrochemically reacting a reducing agent gas containing hydrogen and an oxidant gas containing oxygen such as air. The fuel cell 11 includes a polymer electrolyte membrane that selectively transports hydrogen ions, and a plurality of pairs of electrodes formed on both sides of the polymer electrolyte membrane, that is, a fuel electrode (anode) and a plurality of air electrodes (cathodes). Is done. The anode and the cathode, for example, are mainly composed of carbon powder supporting a platinum-based metal catalyst, a catalyst layer formed on both surfaces of the polymer electrolyte membrane, and an air permeability and an electron formed on the outer surface of the catalyst layer. It is composed of a gas diffusion layer having both conductivity. As the fuel cell 11, for example, a solid polymer form, a phosphoric acid form, a solid oxide form, or the like is used.

  The anode of the fuel cell 11 is connected to the downstream end of the reducing agent gas supply path 15. The upstream end of the reducing agent gas supply path 15 is connected to the hydrogen generator 2. Thereby, the reducing agent gas containing much hydrogen produced | generated with the hydrogen production | generation apparatus 2 is supplied to an anode. The hydrogen generator 2 generates a reducing agent gas containing a large amount of hydrogen necessary for power generation of the fuel cell 11 by adding steam to a hydrocarbon-based raw material such as city gas and performing a reforming reaction.

  The cathode of the fuel cell 11 is connected to the downstream end of the oxidant gas supply path 16. The upstream end of the oxidant gas supply path 16 is connected to the air supply device 3. As a result, the oxidant gas is supplied from the air supply device 3 to the cathode. Air is mainly used as the oxidant gas. For example, a centrifugal pump, a reciprocating pump, a scroll pump, or the like is used as the air supply device 3.

  A coolant pump 5, a coolant temperature sensor 13, a fuel cell 11, a surplus power consumption heater 14, and a heat exchanger 6 are connected to the coolant circulation circuit 4. The coolant is supplied to the fuel cell 11 through the coolant circulation circuit 4 by driving the coolant pump 5. Thereby, the heat generated by the power generation of the fuel cell 11 is removed. After the cooling water is heated by the fuel cell 11, the heat is transferred to the hot water by the heat exchanger 6 to be cooled, and then supplied to the fuel cell 11 again. The surplus power consumption heater 14 is used to heat up and consume surplus power by power generation. The surplus power consumption heater 14 may be inserted into the pipe to directly heat the cooling medium, or may be installed outside the pipe to indirectly supply the cooling medium. You may heat.

  The heat recovery circuit 7 is connected from the lower part of the hot water storage tank 307 to the upper part of the hot water storage tank 307. A heat recovery circulation pump 8 is connected in the middle of the heat recovery circulation circuit 7, and the heat recovery circulation circuit 7 is connected to the heat recovery forward line 7 a from the heat exchanger 6 to the hot water storage tank 307 and from the hot water storage tank 307 to the heat exchanger. And up to 6 heat recovery return lines 7b. A heat recovery temperature sensor 19 a provided in the heat recovery circuit 7 detects the temperature of the hot water that is recovered in the hot water storage tank 307 by recovering the exhaust heat by the power generation device 100. Further, the temperature of hot water flowing out of the hot water storage tank 307 and supplied to the power generation apparatus 100 is detected by a heat recovery temperature sensor 19 b provided in the heat recovery circuit 7. Detection data of the heat recovery temperature sensors 19a and 19b is transmitted to the control device 10 and stored in the storage unit. Details of heat recovery and heat storage in the hot water storage tank 307 will be described later.

  The power converter 9 converts the DC power generated by the fuel cell 11 into AC power and supplies it to the power load. One side of the power converter 9 is connected to the fuel cell 11 via a DC power path 17. Further, the other side of the power converter 9 is connected to a power load (not shown) such as a home appliance or a commercial power source (not shown) via an AC power path 18. An automatic power switch (not shown) is connected to the AC power path 18. When a power failure occurs, this automatic power switch automatically switches the power supply destination from a commercial power source to a dedicated power outlet for power failure (not shown).

  The hot water storage device 200 can use the hot water stored in the hot water storage tank 307 for hot water supply, bathing, heating, and the like. The hot water storage device 200 has a hot water supply function, a bath reheating function, and a heating function, and is formed by thermally connecting the heating terminal 50 (50a to 50c) and the bathtub 27. A heating circuit 21 that circulates a liquid (for example, hot water) to the heating terminal 50 (50a to 50c) includes pipes 89, 90, 91, 92, 93, 94, 95, 96 provided in the housing of the hot water storage device 200. 97, 98, 99 and pipes 40, 41, 44, 45, 59 provided outside the hot water storage apparatus 200.

  The conduit 40 is connected to the conduit 97, the conduits 41 and 44 are connected to the conduit 95 via the liquid confluence means 35 and the conduit 59, and the conduit 45 is connected to the conduit 90 via the liquid branching means 37. It is connected. An internal passage 51 of the heating terminal 50a is connected to the pipelines 40 and 41, and an internal passage 52 of the heating terminals 50b and 50c is connected to the pipelines 44 and 45, respectively. The heating terminals 50b and 50c are low-temperature heating terminals such as hot water mats. The heating terminal 50a is a high-temperature heating terminal such as a bathroom heater to which a liquid having a predetermined high-temperature heating set temperature (for example, 80 ° C.) is supplied. A heating valve 53 is provided in the heating terminal 50a. It should be noted that a heating terminal other than that shown in the figure can be connected to the liquid branching means 37 and the liquid joining means 35 as necessary.

  The heating circuit 21 includes a heating circulation pump 26 that circulates liquid in the heating circuit 21 and a heating heat exchanger 28 (heating latent heat exchanger 28a, heating) that heats the liquid circulated by driving the heating circulation pump 26. A sensible heat exchanger 28b) is provided. A pipe 95 is connected to the liquid introduction side of the heating latent heat exchanger 28a, a pipe 94 is connected to the liquid discharge side, and a pipe 91 is connected to the liquid introduction side of the heating sensible heat exchanger 28b. Pipe lines 92 are connected to the liquid outlet side. A heating high temperature sensor 33 is provided in the pipe line 92 to detect the temperature of the liquid exiting from the heating sensible heat exchanger 28b.

  Further, the pipe line 91 is connected to the discharge side of the heating circulation pump 26 together with the pipe line 90, and the pipe line 91 has a heating low temperature for detecting the temperature of the liquid introduced into the heating sensible heat exchanger 28b. A temperature sensor 36 is provided. In addition, a pipe 93 is connected to the suction port side of the heating circulation pump 26, and a cistern device 60 is interposed between the pipe 93 and the pipe 94. A makeup water electromagnetic valve 61 is provided in the upper part of the cistern device 60, and a makeup water passage 57 branched from the water supply passage 101a is connected to the makeup water electromagnetic valve 61. When the makeup water electromagnetic valve 61 is switched to the valve open state, makeup water is supplied to the cistern device 60 via the makeup water passage 57.

  Heating heat exchangers 28 (heating latent heat exchangers 28a and heating sensible heat exchangers 28b) are respectively provided in the combustion chamber 24, and together with the heating heat exchanger 28, A burner 46 for heating the heating heat exchanger 28 and a combustion fan 48 for supplying and exhausting combustion of the burner 46 are provided. A combustion chamber 25 is provided in communication with the combustion chamber 24, and a burner 47 and a hot water supply heat exchanger 29 (29 a, 29 b) heated by the burner 47 are provided in the combustion chamber 25. Yes.

  Gas pipes 31 and 32 for supplying fuel to the respective burners 46 and 47 are connected to the burners 46 and 47. These gas pipes 31 and 32 are branched from the gas pipe 30, and a gas on / off valve 80 is interposed in the gas pipe 30. The gas pipe 31 is provided with a gas proportional valve 86 and gas on-off valves 81, 82, 83, 84, and 85, respectively. These valves 80 to 86 are all formed by electromagnetic valves, the gas on-off valves 80 to 85 control the fuel supply / stop to the corresponding burners 46 and 47, and the gas proportional valve 86 includes the burner 46, The amount of fuel supplied to 47 is controlled by the valve opening. The combustion control of the burners 46 and 47 is controlled by the control device 10 by an appropriate control method.

  The water supply system passage 101 supplies low temperature clean water from a water supply source to the hot water storage tank 307, and includes a water supply passage 101a and a water supply passage 101b. The water supply passage 101 a is connected to a water supply source, and the water supply passage 101 b is branched from the water supply passage 101 a and connected to the lower part of the hot water storage tank 307. The water supply passage 101a is provided with a flow rate sensor 102, a water supply temperature sensor 103, a pressure reducing valve 104, and a mixing valve 105, and the water supply passage 101b is provided with a check valve 107.

  The hot water supply system passage 201 supplies hot water stored in the hot water storage tank 307 to a hot water supply destination such as a hot water tap, and a hot water supply passage 201a through which high temperature hot water flows, and a mixture of low temperature hot water and high temperature hot water. It consists of a hot water supply passage 201b through which hot water flows and a hot water supply passage 201c connected to a hot water supply destination such as a hot water tap. A hot water supply temperature sensor 202 and a mixing valve 203 are provided in the hot water supply passage 201a. The mixing valve 203 and the mixing valve 105 provided in the water supply passage 101a through which the low temperature clean water flows adjusts the mixing amount of the low temperature clean water and the high temperature hot water, and flows through the hot water supply passage 201b as the mixed hot water. The heat exchanger 29a is introduced. The hot water supply passage 201b is provided with a flow rate sensor 73 for detecting the flow of hot water flowing through the hot water supply passage 201b and a mixed hot water temperature sensor 74 for detecting the temperature of the hot water. A hot water supply passage 201c is provided on the outlet side of the hot water supply heat exchanger 29b, and hot water flows through the hot water supply passage 201c and is guided to a hot water supply destination such as a hot water tap. The hot water supply passage 201 c is connected to the hot water supply passage 201 b through the branch passage 70 and the hot water passage switching valve 58. The hot water supply passage 201c is provided with a hot water temperature sensor 113 on the downstream side of the branch portion of the branch passage 70, and a can body temperature sensor 114 on the hot water supply heat exchanger 29 side.

  A recirculation circuit 63 having a bath outlet pipe 63a and a bath return pipe 63b is connected to the bathtub 27, and the recirculation circuit 63 has bath heat as heat exchange means (liquid-liquid heat exchanger). It is thermally connected to the heating circuit 21 via the exchanger 67. Note that a reflow rate control valve 38 is provided at the inlet of the bath heat exchanger 67 in the pipe line 89 forming the bath heat exchanger 67 of the heating circuit 21. The recirculation circuit 63 is provided with a bath circulation pump 68 that circulates the bath water. The bath heat exchanger 67 drives the bath water that circulates in the recirculation circuit 63 by driving the bath circulation pump 68. Heat exchanger.

  The recirculation circuit 63 has a bath temperature sensor 64a for detecting the temperature of hot water flowing to the bath return pipe 63a, a bath return temperature sensor 64b for detecting the temperature of hot water flowing from the bath return pipe 63b, A water level sensor 65 for detecting the water level of the bathtub hot water and a bath water flow switch 66 for detecting the water flow of the recirculation circuit 63 are provided. One end side of the bath return pipe 63 b is connected to the suction port side of the bath circulation pump 68, and the other end side of the bath return pipe 63 b is connected to the bathtub 27 via the circulation fitting 56. One end side of the bath outlet pipe 63 a is connected to the discharge port side of the bath circulation pump 68, and the other end side of the bath outlet pipe 63 a is connected to the bathtub 27 via the circulation fitting 56.

  Further, a hot water supply unit 55 is connected to the hot water supply passage 201c via a pipe line 54 on the downstream side of the formation portion of the branch passage 70 and the arrangement portion of the hot water temperature sensor 113. One end side of the hot water passage 23 is connected to the hot water unit 55, and the other end side of the hot water passage 23 is connected to the bath circulation pump 68. The hot water supply unit 55 is provided with a hot water solenoid valve 42, check valves 43a and 43b, and a hot water sensor 49. From the hot water supply heat exchanger 29 to the bathtub 27 through the hot water supply passage 201c and the pipe 54, the hot water supply unit 55, the hot water supply passage 23, the bath circulation pump 68, the bath heat exchanger 67, and the bath outlet pipe 63a in this order. This passage constitutes a hot water injection passage for hot water filling and water injection.

  When the heating operation of the heating terminal 50 is performed, the heating heat exchanger 28 is heated by the burner 46 and the heating circulation pump 26 is driven. Thereby, the liquid of the heating circuit 21 circulates as shown by arrows N to T in FIG. That is, the liquid introduced into the heating latent heat exchanger 28a from the pipe 95 and heated by the heating latent heat exchanger 28a passes through the cistern device 60, and is introduced into the heating circulation pump 26 through the pipe 93.

  In the state where the thermal valve 39 of the liquid branching means 37 is open, the liquid flows from the discharge side of the heating circulation pump 26 to the pipe line 90 side and the pipe line 91 side, and then flows to the pipe line 90 side. The liquid is introduced into the heating terminals 50b and 50c through the pipe lines 90 and 45 in order. Further, the liquid introduced from the discharge side of the heating circulation pump 26 to the pipe 91 side is introduced into the heating sensible heat exchanger 28b through the pipe 91 and further heated by the heating sensible heat exchanger 28b. After a high temperature (for example, about 80 ° C.), the pipe 92 is introduced.

  In the state where the thermal valve 53 of the heating terminal 50a is open, the liquid that has passed through the conduit 92 flows to the conduit 97 side and the conduit 89 side, respectively, and the conduit 89 side (the bath heat exchanger 67). The liquid that has flowed to the side) passes through the pipe 96 and returns to the pipe 95. Further, the liquid that has flowed to the pipe line 97 side is introduced into the heating terminal 50 a through the pipe line 40. The liquid introduced into the heating terminals 50a to 50c passes through the corresponding pipelines 41 and 44 and the liquid merging means 35 and returns to the pipeline 95 (hereinafter, the pipeline 95 is referred to as a “heating return pipeline”). Sometimes). When the thermal valves 53 and 39 are closed, the liquid flows to the heating terminal 50 connected to the thermal valves 53 and 39 (the heating terminals 50b and 50c through the pipes 90 and 45). And the flow to the heating terminal 50a through the pipes 97 and 40) are stopped.

  Further, for example, when a bath hot water refilling instruction is received from a remote control device (not shown), the bath circulation pump 68 is driven. Thereby, while the liquid in the heating circuit 21 circulates through the bath heat exchanger 67, the bathtub hot water in the recirculation circuit 63 circulates as shown by the arrow U in FIG. By exchanging heat between the hot water in the bathtub and the liquid passing through the heating circuit 21 via the bath heat exchanger 67, the reheating operation of the hot water in the bathtub 27 is performed. During this reheating operation, the burner 46 is burned so that the temperature of the heating high temperature sensor 33 becomes a set temperature (for example, 80 ° C.), and until the temperature detected by a bath temperature sensor (not shown) becomes the bath set temperature. The liquid in the heating circuit 21 and the bath water in the recirculation circuit 63 are circulated. When the detected temperature of the bath temperature sensor reaches the bath set temperature, the combustion of the burner 46 is stopped, and the heating circulation pump 26 and the bath circulation pump 68 are stopped after a predetermined post pump time has elapsed.

  Furthermore, when performing hot water filling (automatic hot water filling operation) to the bathtub 27, the water passing through the hot water supply heat exchanger 29 is heated by the combustion of the burner 47, and hot water is poured into the bathtub 27 through the hot water filling water passage. After the automatic hot water filling, the temperature detected by the bath temperature sensor is monitored during a warming operation time of, for example, 4 hours, and the detected temperature exceeds a predetermined allowable range from a preset bath set temperature. When the temperature drops, the reheating operation is performed for 3 minutes, for example, and the operation of the function of the heat retention mode is performed so that the temperature detected by the bath temperature sensor becomes the bath set temperature.

  The control device 10 controls each device constituting the cogeneration system 1 described above. The control device 10 includes a control unit exemplified by a microprocessor and a CPU, a storage unit configured by a memory or the like that stores a program and control parameters for executing each control operation, a timer, and the like. And the control apparatus 10 controls various operation | movement of the cogeneration system 1 by a control part reading the predetermined | prescribed control program stored in the memory | storage part, and performing this.

  Next, a hot water supply system used in the above-described cogeneration system 1 will be described in detail. FIG. 5 is a schematic diagram showing a conventional hot water supply system 300 as an example. In FIG. 5, a low temperature side pipe 309 and a high temperature side pipe 311 correspond to the heat recovery return pipe 7b and the heat recovery forward pipe 7a in FIG. 4, respectively. In FIG. 5, a hot water supply pipe 313 and a water supply pipe 315 correspond to the hot water supply path 201a and the water supply path 101b in FIG. 4, respectively. 5 corresponds to the power generation apparatus 100 in FIG. The hot water supply system 300 includes a hot water supply unit 303 and a heat source 305. The heat source 305 is a generator, for example, and generates heat during power generation.

  In the hot water supply unit 303, a hot water storage tank 307 is disposed in the case 317. A water supply pipe 315 is connected to the lower part of the hot water storage tank 307. When water is supplied to the water supply pipe 315 (arrow G in the figure), low temperature water can be supplied from the lower part of the hot water storage tank 307 into the hot water storage tank 307 (arrow H in the figure).

  A low temperature side pipe 309 is connected to the lower part of the hot water storage tank 307, and a high temperature side pipe 311 is connected to the upper part of the hot water storage tank 307. The low temperature side pipe 309 and the high temperature side pipe 311 are connected by a heat source 305, and water is circulated to the heat source 305 by a pump connected to the low temperature side pipe 309 or the high temperature side pipe 311. That is, low temperature water is sent from the hot water storage tank 307 to the heat source 305 through the low temperature side pipe 309 to the heat source 305 (arrow I in the figure), and heat exchange between the water and the heat source 305 is performed in the heat source 305. The water inside rises. That is, the heat source 305 can be cooled by water in the low temperature side pipe 309. The hot water obtained from the heat source 305 is sent to the hot water storage tank 307 via the high temperature side pipe 311 (arrow J in the figure).

  In this way, the hot water storage tank 307 is supplied with low temperature water from below and high temperature hot water returns to the upper part, so that hot water is stored in the upper part of the hot water storage tank 307 and in the lower part. Cold water is stored. That is, a temperature boundary layer exists inside the hot water storage tank 307. The hot water storage tank 307 is provided with temperature sensors 22a to 22e for each predetermined water level, so that the hot water temperature in the hot water storage tank 307 and the position of the boundary layer can be grasped. When using hot water, hot water is discharged from a hot water supply pipe 313 connected to the upper part of the hot water storage tank 307 (arrow K in the figure), and hot water can be supplied to the outside via the mixer 325. (Arrow L in the figure). At this time, the temperature of the hot water is measured by the tank outlet thermistor 321, and the temperature of the low temperature water is measured by the water supply thermistor 329. These are mixed by the mixer 325 so that it may become set temperature. The hot water supply temperature is measured by the mixing thermistor 331.

  Here, in order to store hot water in the hot water storage tank 307, heat exchange with the heat source 305 is required. However, depending on the operating condition of the heat source 305, hot water cannot be efficiently stored. For example, if the heat source 305 is not operating when using a large amount of hot water, the hot water will be used up and another temperature raising device will be required. In addition, when the heat source 305 continues to operate, if no hot water is used, low-temperature water is not sent to the heat source 305, cooling of the heat source 305 becomes insufficient, and another cooling path is required. Heat cannot be used effectively.

  In order to absorb such a difference between the operation of the heat source 305 and the use of hot water and efficiently use the heat of the heat source 305, the capacity of the hot water storage tank 307 needs to be increased. However, the increase in the size of the hot water storage tank 307 is limited by the installation space and cost. On the other hand, there is a method of using the capacity of the piping as the capacity of the hot water storage tank 307. However, when the capacity of the pipe is increased in this way, for example, hot water in the hot water supply pipe 313 is cooled and the temperature is lowered. For this reason, there is a possibility that the hot water supply temperature immediately after tapping will not be stable.

  For example, the mixing ratio of water and hot water for obtaining hot water of a predetermined temperature differs depending on whether relatively low-temperature hot water in the pipe in the initial stage of hot water supply flows or hot water in the hot water storage tank 307 flows. Therefore, until the temperature of the hot water in the hot water supply pipe 313 is stabilized, the temperature adjustment is not in time, and the temperature change becomes large.

  In order to avoid such a temperature drop of the hot water in the pipe, there is a method of circulating hot water heated by another heat source around the pipe (for example, Patent Document 1).

JP 60-216143 A

  However, if a separate heat source is used as in Patent Document 1, it cannot be said that the heat of the heat source 305 is effectively used, and the hot water supply system itself is complicated. In addition, a system is required to store the hot water to be circulated, so the equipment will be enlarged.

  The present invention has been made in view of the above-described viewpoints, and an object of the present invention is to provide a compact hot water supply unit and a hot water supply system that can perform stable temperature adjustment from the initial stage of hot water supply and have a simple structure.

  In order to achieve the above-described object, the first invention includes a hot water storage tank capable of storing hot water, a high temperature side pipe connected to the upper side of the hot water storage tank for returning high temperature hot water from a heat source to the hot water storage tank, and the hot water storage A low-temperature side pipe connected to the lower side of the tank for sending low-temperature water to a heat source; a hot-water supply pipe connected to the upper side of the hot water storage tank for supplying hot water using the hot water of the hot water storage tank; and a lower side of the hot water storage tank. A hot water supply pipe for supplying water to the hot water storage tank, wherein the high temperature side pipe and the hot water supply pipe are close to each other, and the hot water in the high temperature side pipe and the hot water in the hot water supply pipe are heated. It is a hot water supply unit characterized in that it can be replaced.

  The low temperature side pipe and the water supply pipe may be close to each other, and heat exchange between the water in the low temperature side pipe and the water in the water supply pipe may be possible.

  A heat insulating material is disposed around the hot water storage tank, a notch is formed in a part of the outer peripheral portion of the heat insulating material, the high temperature side pipe and the hot water supply pipe are disposed in the notch, The high temperature side pipe and the hot water supply pipe may be pressed toward each other by a heat insulating piece that closes the notch.

  At least a part of the high temperature side pipe and the hot water supply pipe may be constituted by a double pipe.

  According to the first invention, since the high temperature side pipe and the hot water supply pipe are close to each other and heat exchange between the hot water in the high temperature side pipe and the hot water in the hot water supply pipe is possible, the hot water in the hot water supply pipe is also stored in the hot water. It can be used as hot water in the tank. For this reason, the effect similar to having enlarged the hot water storage tank can be acquired. Moreover, since it is suppressed that the temperature of the hot water in hot water supply piping falls, hot water supply can be performed at the stable temperature from the initial stage of hot water supply.

  Furthermore, if the low-temperature side piping and the water supply piping are close to each other and heat exchange between the water in the low-temperature side piping and the water in the water supply piping is possible, temperature fluctuations in the low-temperature side piping can be suppressed. The heat source can be efficiently cooled.

  Moreover, the high temperature side pipe and the hot water supply pipe are arranged in the notch part of the heat insulating material, and the high temperature side pipe and the hot water supply pipe are pressed and brought close to each other by the heat insulating piece that closes the notch part, so that the high temperature side can be efficiently Heat exchange between the piping and the hot water supply piping can be performed.

  Moreover, heat exchange with a high temperature side piping and hot water supply piping can be performed efficiently by comprising at least one part of high temperature side piping and hot water supply piping with a double pipe.

  A second aspect of the invention is a hot water supply system that includes the hot water supply unit according to the first aspect of the invention and a heat source, and is capable of using the hot water of the hot water storage tank. Water is sent to the heat source, and hot water from the heat source is returned to the hot water storage tank by the high temperature side pipe.

  The heat source may be a power generation device, and the hot water supply system may be a cogeneration system.

  According to the second invention, it is possible to effectively use the heat of the heat source, and a compact hot water supply system can be obtained. In particular, if the heat source is a power generation device, a cogeneration system that can efficiently use heat can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the stable temperature adjustment is possible from the hot water supply initial stage, and a compact hot water supply unit and hot water supply system with a simple structure can be provided.

Schematic which shows the hot water supply system 400. FIG. It is the MM line sectional schematic of FIG. 1, (a) is a figure which shows the state which removed the heat insulation piece 335, (b) is a figure which shows the state which attached the heat insulation piece 335. Schematic which shows the hot water supply system 400a. The figure which shows the whole structure of the conventional cogeneration system 1. Schematic which shows the conventional hot water supply system 300. FIG.

  Hereinafter, a hot water supply system according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a configuration of a hot water supply system 400. The hot water supply system 400 mainly includes a hot water supply unit 403 and a heat source 305. The heat source 305 is a power generation device such as a fuel cell. In this case, the hot water supply system 400 is a part of the cogeneration system 1 described above. In addition, about the structure of the cogeneration system using the hot water supply system 400, since it is the same as that of FIG. 4, the overlapping description is abbreviate | omitted. In this case, as described above, in FIG. 1, the low temperature side pipe 309 and the high temperature side pipe 311 respectively correspond to the heat recovery return pipe 7b and the heat recovery forward pipe 7a in FIG. In FIG. 1, a hot water supply pipe 313 and a water supply pipe 315 correspond to the hot water supply path 201a and the water supply path 101b in FIG. 4, respectively. 1 corresponds to the power generation apparatus 100 in FIG. The heat source 305 may be an engine generator or a light receiving unit of a solar water heater. That is, the heat source 305 may be any device as long as it can exchange heat with water circulating inside and heat the water.

  In the hot water supply unit 403, a hot water storage tank 307 is disposed in the case 317. In addition, in the case 317 and around the hot water storage tank 307 and the piping, a heat insulating material (not shown) is arranged. That is, a heat insulating material is disposed between each pipe and the hot water storage tank 307. Thereby, the heat exchange between the hot water storage tank 307 and each piping is suppressed. Each pipe exposed to the outside of the case 317 is covered with a heat insulating material (not shown).

  A water supply pipe 315 is connected below the hot water storage tank 307. When water is supplied to the water supply pipe 315 (arrow A in the figure), low temperature water can be supplied from the lower part of the hot water storage tank 307 to the inside of the hot water storage tank 307 (arrow B in the figure).

  A low temperature side pipe 309 is connected below the hot water storage tank 307. The low temperature side pipe 309 is a pipe that sends low temperature water to the heat source 305 (arrow C in the figure). The heat source 305 can be cooled by low-temperature water flowing through the low-temperature side pipe 309.

  The low temperature side pipe 309 is connected to the high temperature side pipe 311 at the heat source 305, and the high temperature side pipe 311 is connected above the hot water storage tank 307. The high temperature side pipe 311 is a pipe that returns high temperature hot water from the heat source 305 to the hot water storage tank 307 (arrow D in the figure). That is, the hot water after cooling the heat source 305 flows through the high temperature side pipe 311, is returned to the hot water storage tank 307, and can be stored. Note that a pump is connected to the low temperature side pipe 309 or the high temperature side pipe 311, and water can be circulated to the heat source 305 by the pump as described above. In this way, the hot water storage tank 307 is supplied with low-temperature water from below by the water supply pipe 315, and high-temperature hot water is returned to the upper side by the high-temperature side pipe 311. Hot water is stored, and low temperature water is stored in the lower part.

  The hot water storage tank 307 has, for example, a capacity of about 90 liters, and a first temperature sensor 22a that detects the water temperature at the water level of 18 liters from the bottom has a water level of 36 liters from the bottom. The second temperature sensor 22b for detecting the water temperature at the location is located at a location where the water level is 54 liters from the bottom, and the third temperature sensor 22c for detecting the water temperature at the location is located at a location where the water level is 72 liters from the bottom. A hot water temperature sensor 22d for detecting the water temperature at the location is further provided, and a tank upper temperature sensor 22e for detecting the water temperature at the location is provided at a substantially uppermost position in the hot water storage tank 307, respectively.

  As described above, the hot water is supplied from the lower water supply pipe 315 of the hot water storage tank 307, and the hot water heated by the heat source 305 is returned to the upper part of the hot water storage tank 307. A temperature gradient is formed such that the temperature is high. By continuing the exhaust heat recovery operation, the amount of hot water that accumulates in the upper portion gradually increases.

  When using hot water in the hot water storage tank 307, hot water is discharged from the hot water supply pipe 313 connected to the upper part of the hot water storage tank 307 (arrow E in the figure), and hot water is supplied via the mixer 325. It can be used (arrow F in the figure). At this time, the temperature of the hot water is measured by the tank outlet thermistor 321, and the temperature of the low temperature water is measured by the water supply thermistor 329. These are mixed by the mixer 325 using feedforward control so that it may become set temperature. The hot water supply temperature is measured by the mixing thermistor 331 and feedback controlled.

  Further, when hot water in the hot water storage tank 307 is used, low temperature water is supplied from the lower side of the hot water storage tank 307 through the water supply pipe 315. The amount of water flowing to the water supply pipe 315 is measured by the flow sensor 327. Further, if the pressure in the hot water storage tank 307 becomes too high, hot water is discharged from the overpressure relief valve 323 and the pressure is prevented from rising excessively.

  In the hot water supply unit 403, the high temperature side pipe 311 and the hot water supply pipe 313 are arranged close to each other. 2A and 2B are schematic views showing the form of the heat insulating material 333 in the cross section taken along the line MM in FIG. As described above, the heat insulating material 333 is disposed around the hot water storage tank 307 in the case 317. The hot water storage tank 307 and each pipe are insulated by the heat insulating material 333.

  A notch 337 is formed in a part of the outer periphery of the heat insulating material 333. The notch 337 is formed along the high temperature side pipe 311 and the hot water supply pipe 313. Moreover, the heat insulation piece 335 of the shape according to the shape of the notch part 337 is used. The heat insulating piece 335 has substantially the same outer shape as the notch 337, and further has a shape in which only a portion where the pipe is disposed is cut into a concave shape.

  As shown in FIG. 2B, when the high temperature side pipe 311 and the hot water supply pipe 313 are arranged in the notch 337 and the heat insulating piece 335 is inserted into the notch 337 so as to close the notch 337, both The pipe is guided and pushed into the recess of the heat insulating piece 335. At this time, it is more preferable to apply a silicon-based lubricant. Silicon-based lubricants serve as a heat transfer material, although not as much as silicon grease, together with the role of the lubricant. For this reason, the high temperature side pipe 311 and the hot water supply pipe 313 can be pressed and brought close to each other only by pushing the heat insulating piece 335 into the notch 337. Note that the method of performing heat exchange by bringing the hot water supply pipe 313 and the high temperature side pipe 311 close to each other is not limited to the illustrated example.

  As described above, when the heat source 305 is used even when hot water is not being supplied, hot water flows in the high temperature side pipe 311. Therefore, the hot water in the hot water supply pipe 313 is heated by the hot water in the high temperature side pipe 311 by exchanging heat between the hot water in the high temperature side pipe 311 and the hot water in the hot water supply pipe 313. As a result, the temperature drop of the hot water in the hot water supply pipe 313 can be suppressed.

  In particular, the high temperature side pipe 311 returning from the heat source 305 is a portion through which the hottest hot water flows. For this reason, heat exchange with the hot water supply pipe 313 can be performed efficiently. In this way, the hot water temperature inside the hot water supply pipe 313 and the high temperature side pipe 311 becomes close by heat exchange between the hot water supply pipe 313 and the high temperature side pipe 311. The hot water in the high temperature side pipe 311 after heat exchange is stored in the hot water storage tank 307. For this reason, the hot water temperature in the high temperature side pipe 311 after heat exchange with the hot water supply pipe 313 and the hot water temperature in the hot water storage tank 307 are substantially the same. For this reason, the difference between the hot water temperature in the hot water supply pipe 313 and the hot water temperature in the hot water storage tank 307 is reduced, and there is little change in hot water temperature immediately after the start of hot water supply, and hot water can be supplied at a stable hot water temperature from the beginning of use. it can.

  In addition, the temperature of the hot water in the hot water supply pipe 313 can be raised using the heat of the heat source 305. For this reason, the effect similar to having increased the capacity | capacitance of the hot water storage tank 307 can be acquired, without enlarging the hot water storage tank 307. The hot water supply pipe 313 and the high temperature side pipe 311 are in contact with each other in a substantially vertical shape, and the hot water in the hot water supply pipe 313 reaches the maximum temperature on the lower side that comes into contact first. The hot water that has reached a high temperature convects in a substantially vertical pipe and reaches the upper side, and is used as feedforward control data when mixing at the mixer 325 while grasping the degree of heat exchange at the tank outlet thermistor 321. Note that the pipe diameters of the hot water supply pipe 313 and the high temperature side pipe 311 are preferably sufficiently large so as not to cause resistance to convection in the pipe. For example, the pipe diameter may be about the outer diameter φ14, the inner diameter φ10, or more. desirable.

  In the present embodiment, the low temperature side pipe 309 and the water supply pipe 315 are closer to each other. For example, with the structure shown in FIG. 2B, the low temperature side pipe 309 and the water supply pipe 315 can be brought close to each other. Therefore, heat exchange between the water in the low temperature side pipe 309 and the water in the water supply pipe 315 is possible.

  By doing in this way, since the temperature of the water which flows into the heat source 305 can be made low, the cooling capacity of the heat source 305 can be improved. For example, when the heat source 305 continues to be used in a state where hot water is not supplied, the boundary between the hot water and the low temperature water in the hot water storage tank 307 is lowered. Therefore, the cooling capacity of the heat source 305 decreases when the vicinity of the boundary or high-temperature hot water starts to be sucked. If the hot water storage tank 307 is increased in size, the capacity of the low temperature part can be increased. However, as described above, there is a limitation in increasing the size of the hot water storage tank 307.

  On the other hand, in the present embodiment, the low temperature side pipe 309 and the water supply pipe 315 can be brought close to each other to exchange heat between the water in the low temperature side pipe 309 and the water in the water supply pipe 315. For this reason, the effect similar to having increased the capacity | capacitance of the hot water storage tank 307 can be acquired. Moreover, since the temperature of the water replenished to the hot water storage tank 307 rises, the temperature drop in the hot water storage tank 307 can be suppressed. Note that heat exchange between the low temperature side pipe 309 and the water supply pipe 315 is not always essential.

  As described above, according to the present embodiment, the high temperature side pipe 311 and the hot water supply pipe 313 are brought close to each other to exchange heat between the hot water in the high temperature side pipe 311 and the hot water in the hot water supply pipe 313, thereby supplying heat from the heat source 305. It can be used for raising the temperature of hot water in the pipe 313. For this reason, the effect similar to having increased the capacity | capacitance of the hot water storage tank 307 can be acquired, without enlarging the hot water storage tank 307. For this reason, the hot water supply unit 403 can be made compact.

  Moreover, the hot water in the hot water storage tank 307 and the hot water in the hot water supply pipe 313 are suppressed by exchanging heat between the hot water in the high temperature side pipe 311 and the hot water in the hot water supply pipe 313. The difference in temperature can be reduced. For this reason, there is little fluctuation in hot water temperature after the start of hot water supply, and hot water having a stable temperature can be used.

  Moreover, the notch part 337 is formed in the heat insulating material 333, the high temperature side piping 311 and the hot water supply piping 313 are arrange | positioned in the notch part 337, and it closes with the heat insulation piece 335, and makes both close and heat-exchange efficiently. be able to.

  Further, the low temperature side pipe 309 and the water supply pipe 315 can be brought close to each other so that the water in the low temperature side pipe 309 and the water in the water supply pipe 315 can exchange heat. For this reason, the water temperature in the low temperature side piping 309 is cooled with the water in the water supply piping 315, and the fall of cooling capacity can be suppressed. Thus, the same effect as increasing the capacity of the hot water storage tank 307 can be obtained without increasing the size of the hot water storage tank 307.

  Next, a second embodiment will be described. FIG. 3 is a schematic diagram showing a hot water supply system 400a according to the second embodiment. In the following description, components having the same functions as those of the hot water supply system 400 are denoted by the same reference numerals as those in FIG.

  The hot water supply system 400a has substantially the same configuration as the hot water supply system 400, but the proximity state between the pipes is different. In the hot water supply system 400a, the high temperature side pipe 311 and the hot water supply pipe 313 are not in contact with each other, but a part of the hot water supply system 400a is constituted by a double pipe. In the illustrated example, a part of the hot water supply pipe 313 is disposed inside the high temperature side pipe 311.

  Similarly, in the hot water supply system 400a, the outer surfaces of the low temperature side pipe 309 and the water supply pipe 315 are not in contact with each other but partly constituted by double pipes. In the illustrated example, a part of the water supply pipe 315 is disposed inside the low temperature side pipe 309.

  In this way, by making a part of the pipe a double pipe and bringing the pipes close together inside and outside the pipe, heat exchange between them can be performed efficiently. Even if a part of the pipe is a double pipe, by setting the pipe diameter sufficiently large so as not to cause resistance to convection in the pipe, convection is generated in the pipe, and hot water below is convected upward. Can be made.

  According to the second embodiment, an effect similar to that of the first embodiment can be obtained. Thus, any form may be sufficient as the proximity | contact form of each piping. For example, the pipes may be brought into contact with each other via a heat conducting member, and a flat pipe or a pipe having a partly flat surface may be used in order to increase the contact area between the pipes.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

1 ... Cogeneration system 2 ... Hydrogen generator 3 ... Air supply device 4 ... Cooling water circulation circuit 5 ... Cooling water pump 6 ... Heat exchanger 7 ... Heat recovery circulation circuit 7a ......... Heat recovery forward pipe 7b ......... Heat recovery return pipe 8 ......... Heat recovery circulation pump 9 ......... Power converter 10 ......... Control device 11 ...... Fuel cell 13 ......... Cooling Temperature sensor 14... Surplus power consumption heater 15... Reducing agent gas supply path 16... Oxidant gas supply path 17 .. DC power path 18 ....... AC power paths 19 a and 19 b. Temperature sensor 21 ... Heating circuit 23 ... Hot water passages 24, 25 ... Combustion chamber 26 ... Heating circulation pump 27 ... Bath 28 ... Heating heat exchanger 28a ... Heating latent heat Exchanger 28b ... Heating sensible heat exchanger 29, 29a, 29b ...... Heat-exchanger heat exchangers 30, 31, 32 .... gas pipe 33 .... heating high temperature sensor 35 .... liquid merging means 36 .... heating low temperature sensor 37 .... liquid branching means 38 .... ... reheating flow control valves 39, 53 ..... Thermal valves 40, 41, 44, 45, 54, 59, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 ... ... Pipe line 42 ... ... Filled solenoid valves 43a, 43b, 107 ... ... Check valves 46, 47, 48 ... ... Burner 48 ... ... Combustion fan 49 ... ... Filled water amount sensors 50, 50a and 50b , 50c ......... Heating terminals 51, 52 ......... Internal passage 55 ......... Tap water unit 56 ......... Circuit fitting 57 ......... Supply water passage 58 ...... Hot water path switching valve 60 ......... Sis turn device 61 ……… Supply water solenoid valve 63 ……… Further circulation circuit 63 ... bath pipe 63b ... bath return pipe 64a ... bath room temperature sensor 64b ... bath return temperature sensor 65 ... water level sensor 66 ... bath water flow switch 67 ... bath heat exchanger 68... Bath circulation pump 70... Branch passages 73 and 102. Gas proportional valve 101... Water supply system passages 101 a and 101 b... Water supply passage 103... Water supply temperature sensor 104. Can body temperature sensor 200... Hot water storage apparatus 201... Hot water supply system passages 201 a, 201 b, 201 c ...... Hot water supply passage 202. 3, 403 ..... Hot water supply unit 305 ..... Heat source 307 ..... Hot water storage tank 309 ..... Low temperature side pipe 311 ..... High temperature side pipe 313 ..... Hot water supply pipe 315 ..... 321 ......... Tank outlet thermistor 323 ......... Overpressure relief valve 325 ......... Mixer 327 ......... Flow sensor 329 ......... Water supply thermistor 331 ......... Mixing thermistor 333 ......... Heat insulation 335 ......... Heat insulation Piece 337 ......... Notch

Claims (6)

A hot water storage tank capable of storing hot water,
A hot pipe connected to the hot water storage tank and returning hot water from a heat source to the hot water storage tank;
A low-temperature side pipe connected to the lower side of the hot water storage tank and sending low-temperature water to a heat source;
A hot water supply pipe connected above the hot water storage tank and supplying hot water using hot water of the hot water storage tank;
A water supply pipe connected below the hot water storage tank and supplying water to the hot water storage tank;
Comprising
The hot water supply unit, wherein the high temperature side pipe and the hot water supply pipe are close to each other and heat exchange between the hot water in the high temperature side pipe and the hot water in the hot water supply pipe is possible.   The hot water supply unit according to claim 1, wherein the low temperature side pipe and the water supply pipe are close to each other and heat exchange between the water in the low temperature side pipe and the water in the water supply pipe is possible. .   A heat insulating material is disposed around the hot water storage tank, a notch is formed in a part of the outer peripheral portion of the heat insulating material, the high temperature side pipe and the hot water supply pipe are disposed in the notch, 3. The hot water supply unit according to claim 1, wherein the high temperature side pipe and the hot water supply pipe are pressed toward each other by a heat insulating piece that closes the notch.   The hot water supply unit according to claim 1 or 2, wherein at least a part of the high temperature side pipe and the hot water supply pipe is constituted by a double pipe.   A hot water supply system comprising the hot water supply unit according to any one of claims 1 to 4 and a heat source, wherein the hot water in the hot water storage tank can be used.   The hot water supply system according to claim 5, wherein the heat source is a power generation device, and the hot water supply system is a cogeneration system.

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