JP3836806B2 - Cogeneration system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cogeneration system (a combined electric and heat supply system). In particular, the present invention relates to a technique for downsizing a space required to accommodate a hot water tank by reducing the number of pipes that need to be connected to the hot water tank.
[0002]
[Prior art]
The cogeneration system includes a power generation unit that generates electric power and generated heat, a hot water tank, a forward pipe that sends water in the hot water tank to the power generation unit, and a return pipe that sends hot water heated by the generated heat to the hot water tank. It heats water using the heat generated by power generation and stores the heated hot water in a hot water tank. Hot water in the hot water tank is adjusted to an appropriate temperature, and hot water is supplied to a hot water use location (for example, a floor heating system, a bath, a shower, a hot water tap, etc.). In order to replenish the water consumed by supplying hot water, a water supply pipe is connected to the hot water tank, and the used amount of water is supplied to the hot water tank. Cogeneration systems are highly energy efficient.
There is a demand for miniaturization of cogeneration systems. Attempts have been made to downsize the entire system by downsizing the hot water tank. (For example, patent document 1).
[0003]
[Patent Document 1]
JP 2001-343159 A
[0004]
[Problems to be solved by the invention]
In order to use the generated heat effectively, it is desirable to secure a large capacity of the hot water storage tank and increase the heat storage capacity. If the hot water tank is downsized to reduce the size of the system, the superiority of the system is lost.
According to the inventor's consideration, the space for storing the hot water storage tank requires a space for storing piping connected to the hot water storage tank in addition to the space for storing the hot water storage tank itself. It was confirmed that the storage space can be considerably reduced by downsizing it.
The present invention reduces the number of pipes that need to be connected to the hot water tank, thereby reducing the size of the hot water tank (and thus without reducing the amount of heat storage possible), and the space required to accommodate the hot water tank. Aims to provide a technology that can be miniaturized.
[0005]
[Means, actions and effects for solving problems]
  The cogeneration system according to the present invention includes a power generation unit, a hot water storage tank, a water supply pipe for supplying tap water to the hot water storage tank, a forward pipe for sending water in the hot water storage tank to the power generation unit, and hot water heated by the generated heat. A return pipe to the hot water tankWith the thermistorIt has.
  In the system according to one aspect of the present invention, the forward pipe also serves as a part of the water supply pipe and is branched from the water supply pipe and connected to the power generation unit.Further, the thermistor is provided between a branch portion where the forward pipe branches off from the water supply pipe and the hot water storage tank, and is provided at a portion which serves both as the water supply pipe and the forward pipe. The thermistor measures the temperature of tap water supplied to the hot water tank and the temperature of water sent from the hot water tank to the power generation unit.
  It is possible to explain the same piping relationship in various ways. For example, it can be said that the water supply pipe is connected to the hot water storage tank through a part of the forward pipe, and the forward pipe is connected to a part of the water supply pipe. It can also be said that it is connected to the hot water storage tank, and it can also be said that the water supply pipe and the forward pipe are connected to the hot water storage tank through a portion (first common pipe) that serves both as the water supply pipe and the forward pipe. Both are synonymous.
[0006]
In said system, the part (1st common pipe) located between the branch part which a forward pipe branches from a water supply pipe, and a hot water storage tank will serve as a water supply pipe and an outgoing pipe. The first common pipe functions as a water supply pipe during hot water supply operation while power generation is stopped, and functions as a forward pipe during power generation operation while hot water supply is stopped.
When hot water is being supplied to a hot water use location while power generation is stopped, the first common pipe is used as a water supply pipe to the hot water storage tank. When power generation is performed while hot water supply is stopped, the first common pipe is used as an outgoing pipe for recovering generated heat. It can also generate electricity while supplying hot water.
Both the water supply pipe and the forward pipe are pipes connected to the lower part of the hot water storage tank, and there is no problem even if the first common pipe is used as the water supply pipe and the forward pipe. Even if the first common pipe is used as the water supply pipe and the forward pipe, the function necessary for the cogeneration system can be secured.
In the conventional technology, both the water supply pipe and the forward pipe must be connected to the hot water tank, but according to the above system, it is only necessary to connect one, and the area around the hot water tank is clean and compact. It can be accommodated.
[0007]
  A cogeneration system according to another aspect of the present invention includes a power generation unit, a hot water tank, a mixing unit that mixes hot water and tap water, a hot water pipe that sends hot water in the hot water tank to the mixing unit, and hot water that stores tap water. A water supply pipe for supplying water to the tank and the mixing unit, a forward pipe for sending water in the hot water storage tank to the power generation unit, and a return pipe for sending hot water heated by the generated heat to the hot water storage tankWith the thermistorIt has.
  In the system of this aspect, the return pipe is connected to the hot water storage tank via the hot water discharge pipe.Furthermore, the thermistor is provided between the junction where the hot water discharge pipe and the return pipe merge and the hot water storage tank, and is provided in a portion which serves as the hot water discharge pipe and the return pipe. The thermistor measures the temperature of hot water sent from the hot water tank to the mixing unit and the temperature of hot water sent from the power generation unit to the hot water tank.
  It is possible to explain the same piping relationship in various ways. For example, the outlet pipe and the return pipe are connected to the hot water storage tank through the portion (second common pipe) that serves as the outlet pipe and the return pipe. It can be said that the return pipe is joined to the hot water pipe, and the hot water pipe is connected to the hot water storage tank through a part of the return pipe. Both are synonymous.
[0008]
In the above system, the portion (second common pipe) that is located between the junction where the hot water pipe and the return pipe merge and the hot water storage tank is used as the hot water pipe and the return pipe (second common pipe) is hot water during hot water supply operation while power generation is stopped. It functions as a pipe, and functions as a return pipe during hot water supply stop and power generation operation.
When hot water is being supplied to the hot water use location while power generation is stopped, the second common pipe is used as a hot water outlet pipe from the hot water storage tank. When electric power is generated while hot water supply is stopped, the second common pipe is used as a return pipe for hot water from which generated heat is recovered. It can also generate electricity while supplying hot water.
Both the hot water outlet pipe and the return pipe are pipes connected to the upper part of the hot water storage tank, and there is no problem even if the hot water outlet pipe and the return pipe are used together in the second common pipe. Even if the hot water pipe and the return pipe are combined in the second common pipe, the function necessary for the cogeneration system can be secured.
In the case of the conventional technology, both the hot water discharge pipe and the return pipe must be connected to the hot water tank, but according to the above system, it is only necessary to connect one, and the hot water tank is neat and compact. It can be accommodated.
[0009]
The first common pipe and the second common pipe can be used in combination. The cogeneration system in this case includes a power generation unit, a hot water tank, a mixing unit that mixes hot water and tap water, a hot water pipe that sends hot water in the hot water tank to the mixing unit, and tap water that is stored in the hot water tank and mixing unit. And a return pipe for sending hot water heated by the power generation heat to the hot water tank.
In the system of the present invention, the forward pipe also serves as a part of the water supply pipe, branches from the water supply pipe and is connected to the power generation unit, and the return pipe is connected to the hot water storage tank via the hot water discharge pipe.
In this case, the first shared pipe functions as a water supply pipe during hot water supply operation while power generation is stopped, and functions as a forward pipe during power generation operation while hot water supply is stopped. The second shared pipe functions as a hot water discharge pipe during hot water supply operation while power generation is stopped, and functions as a return pipe during power generation operation while hot water supply is stopped.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described.
(Mode 1) The second common pipe is relatively thicker than other pipes.
The second common pipe is a pipe of hot water discharged from the hot water tank or a pipe of hot water heated by power generation heat, and in any case, the pipe through which the heated hot water circulates. That is, the hot water in the second common pipe has the same temperature as the hot water stored in the upper part of the hot water tank, and can be regarded as the second hot water tank. By increasing the thickness of the second shared pipe, the amount of hot water stored in the entire system (possible heat storage amount) can be increased without increasing the size of the system and hot water storage tank.
[0011]
【Example】
A first embodiment embodying the present invention will be described with reference to FIGS.
First, the configuration of the cogeneration system will be described. FIG. 1 is a schematic configuration diagram of a cogeneration system according to the present embodiment. As shown in FIG. 1, the cogeneration system 10 includes a power generation unit 20 that generates electric power and generated heat, a heat storage unit 15 that stores heat by storing warm water heated by the generated heat, and uses the warm water. The The heat storage unit 15 includes a hot water storage tank 44 for storing hot water heated by generated heat, a mixing unit 72 for mixing hot water discharged from the hot water storage tank 44 and tap water, and a hot water supply / heating heat source machine (hereinafter referred to as a heat source machine). 50 etc. The heat source unit 50 heats and controls hot water that has passed through the mixing unit 72 and supplies the hot water to the hot water use location 40 and the bathtub 90, warms the hot water in the bathtub 90, warms the heating medium, and heats the heater 92. , 96 to circulate and heat.
[0012]
The power generation unit 20 includes a fuel cell 22, a reformer 30 and the like, and is housed in a power generation unit housing 21. The reformer 30 generates hydrogen gas from hydrocarbon-based raw fuel gas. Since a high temperature is required to efficiently generate the hydrogen gas, the reformer 30 has a burner 32 built therein. Further, a combustion gas exhaust pipe 34 is connected to the reformer 30, and the combustion gas exhaust pipe 34 passes through the heat exchanger 70 to heat water and then is discharged out of the power generation unit housing 21 (FIG. Middle arrow).
The fuel cell 22 is composed of a plurality of cells. A pipe (not shown) communicating with the reformer 30 is connected to the fuel cell 22. Hydrogen gas generated by the reformer 30 is supplied to the fuel cell 22 through the piping. The fuel cell 22 takes in oxygen in the air, and reacts the taken-in oxygen with hydrogen gas supplied from the reformer 30 to generate power.
[0013]
The fuel cell 22 generates heat during power generation. A heat medium circulation pipe 24 is connected to the fuel cell 22, and the heat medium flowing through the heat medium circulation pipe 24 collects generated heat generated during power generation. A heat medium circulation pump 8 is disposed in the heat medium circulation pipe 24. In this embodiment, pure water is used as the heat medium. This pure water is obtained by passing tap water through a pure water generator (not shown).
The heat medium circulation pipe 24 is disposed so as to pass through the heat exchanger 74. The heat generated by the fuel cell 22 recovered by the heat medium is transferred to the heat exchanger 74.
A three-way valve 36 is disposed in the heat medium circulation pipe 24. The three-way valve 36 has one inlet and two outlets. The heat medium circulation pipe 24 is bifurcated by the three-way valve 36. Of the branched heat medium circulation pipe 24, a pipe connected to one outlet of the three-way valve 36 is disposed via the radiator 28, and a pipe connected to the other outlet is the radiator 28. It is arrange | positioned so that it may not be interposed. Which outlet of the three-way valve 36 is opened is controlled by a power generation unit controller (not shown). As a result, it is switched whether the heat medium circulates via the radiator 28 or circulates without passing through the radiator 28. Specifically, when the temperature of the heat medium measured by a thermistor (not shown) is abnormally high, the outlet of the three-way valve 36 is switched so that the heat medium circulates through the radiator 28. The radiator 28 cools the heat medium by blowing air, for example. In addition, illustration 25 is a cis turn.
[0014]
The heat storage unit 15 includes a hot water storage tank 44, a mixing unit 72, a heat source device 50, and the like, and is stored in the heat storage unit housing 16.
The cogeneration system 10 is provided with a water supply pipe 64 for supplying tap water. The water supply pipe 64 is formed with two branch parts 64d and 64c. The branch part 64c branches into two branches, a first water supply pipe 64a and a second water supply pipe 64b (the branch part 64d will be described later). . The first water supply pipe 64 a is connected to the lower part of the hot water storage tank 44. The second water supply pipe 64 b is connected to the cold water inlet 72 b of the mixing unit 72.
A first hot water discharge pipe 52 is connected to the upper part of the hot water storage tank 44, and the first hot water discharge pipe 52 is connected to a hot water inlet 72 a of the mixing unit 72 through a junction 52 a (described later). A first hot water thermistor T <b> 1 is disposed in the first hot water discharge pipe 52 in the vicinity of the connection with the hot water tank 44, and is used to detect the temperature of the hot water discharged from the hot water tank 44.
[0015]
A pressure reducing valve 42 is disposed upstream of the branch portion 64 d of the water supply pipe 64. The pressure reducing valve 42 adjusts the pressure of tap water supplied to the hot water tank 44 and the mixing unit 72. When the hot water in the hot water storage tank 44 decreases or the cold water inlet 72b of the mixing unit 72 opens and the downstream pressure of the pressure reducing valve 42 becomes equal to or lower than the pressure regulation value, the pressure reducing valve 42 opens to enter the hot water storage tank 44 and the mixing unit 72. Supply water. The pressure in the hot water tank 44 is maintained at a pressure lower than the tap water pressure. A water supply thermistor T2 is disposed between the branch part 64c and the branch part 64d of the water supply pipe 64, and is used to detect the temperature of the tap water supplied.
[0016]
A relief valve 46 for releasing the pressure in the hot water storage tank 44 is disposed above the hot water storage tank 44. The pressure in the hot water tank 44 is maintained at 0.17 MPa or less which is the pressure resistance of the hot water tank 44 by the relief valve 46 and the pressure reducing valve 42. The relief valve 46 is provided with a pipe 55 for draining open steam (or hot water).
One end of a drain pipe 54 is connected to the lower part of the hot water tank 44. The other end of the drain pipe 54 is connected to the middle of the drain pipe 55. The drain pipe 54 drains water from the hot water tank 44. A manually operated drain valve 53 is attached to the drain pipe 54. When the drain valve 53 is opened, the hot water stored in the hot water tank 44 is drained to the outside through the drain pipe 54.
The hot water and cold water in the hot water storage tank 44 do not mix with each other by forming a temperature stratification. A hot water tank upper thermistor T <b> 3 is disposed in the upper part of the hot water tank 44, and detects the temperature of the hot water stored in the upper part of the hot water tank 44. A hot water tank lower thermistor T <b> 4 is disposed below the hot water tank 44, and detects the temperature of the cold water stored in the lower part of the hot water tank 44.
[0017]
The mixing unit 72 has a hot water inlet 72a, a cold water inlet 72b, and a mixed water outlet 72c. Hot water in the hot water storage tank 44 flows into the hot water inlet 72a via the first hot water outlet pipe 52, and tap water flows into the cold water inlet 72b via the second water supply pipe 64b. The opening degree of the two inlets 72a and 72b is variable. That is, the inflow ratio of hot water and tap water is variable. These opening degrees are controlled by the control unit 60. By controlling the opening degree, for example, it is possible to shut off tap water (close the cold water inlet 72b) and send out only hot water from the outlet 72c, and conversely shut off hot water (hot water inlet 72a). It is also possible to send out only tap water from the outlet 72c. In addition, for example, 70% hot water and 30% tap water can be mixed and sent out from the outlet 72c, the mixing ratio adjusted to the required temperature can be adjusted by adjusting the mixing ratio of hot water and tap water. 72c can be sent out.
[0018]
The mixed water that has been mixed and adjusted in the mixing unit 72 is discharged from the outlet 72c. A second hot water discharge pipe 76 is connected to the outlet 72c. The second hot water discharge pipe 76 is connected to the hot water supply pipe 94 in the heat source apparatus 50, and connects the mixing unit 72 and the heat source apparatus 50. The pressure reduced by the pressure reducing valve 42 is applied to the two inlets 72 a and 72 b of the mixing unit 72. Therefore, the pressure of the mixed water discharged from the outlet 72 c of the mixing unit 72 is also equal to the pressure adjusted by the pressure reducing valve 42. A second hot water thermistor T <b> 5 is disposed in the second hot water discharge pipe 76 and detects the temperature of the mixed water discharged from the mixing unit 72.
[0019]
Between the heat storage unit 15 and the power generation unit 20, a pipe 4 for recovering the generated heat is disposed.
A part of the forward pipe 4 a of the power generation heat recovery pipe 4 is shared with the water supply pipe 64. That is, a part of the water supply pipe 64 is also used as a part of the forward pipe 4a. A branch portion 64d is formed on the downstream side of the pressure reducing valve 42 of the water supply pipe 64, and the forward dedicated pipe 4a1 is connected to the branch portion 64d. The forward exclusive pipe 4a1 branches from the water supply pipe 64 at the branching portion 64d and enters the power generation unit 20. The forward exclusive pipe 4a1 that has entered the power generation unit 20 passes through the heat exchanger 74 with the generated heat and the heat exchanger 70 with the reformer 30, and becomes the return exclusive pipe 4b1.
The water supply pipe 64 between the hot water storage tank 44 and the branch part 64d is also a water supply pipe 64 and a part of the outgoing pipe 4a, and a function of supplying tap water to the hot water storage tank and a function of supplying water to the power generation unit 21. Is also used. Hereinafter, this portion is referred to as a first common pipe 66. When tap water is supplied to the hot water tank, the tap water flows through the first common pipe 66 toward the hot water tank 44, and when water is supplied to the power generation unit 21, the cold water at the bottom of the hot water tank 44 is the first. It flows out to the common pipe 66.
[0020]
A part of the return pipe 4b of the power generation heat recovery pipe 4 is shared with the tapping pipe. That is, the first hot water discharge pipe 52 is also used as a part of the return pipe 4b. A junction 52a is formed in the vicinity of the mixing unit 72 of the first outlet pipe 52, and the return dedicated pipe 4b1 of the power generation heat recovery pipe 4 is connected to the junction 52a. The return dedicated pipe 4 b 1 is connected to the upper part of the hot water storage tank 44 via the first hot water discharge pipe 52.
The first hot water pipe 52 is also a hot water pipe and a part of the return pipe 4b. The hot water stored in the upper part of the hot water tank is sent to the mixing unit 72 and the hot water heated by the power generation unit 21 is stored in the hot water. Combines the function of returning to the top of the tank. Hereinafter, this portion is referred to as a second shared pipe 68. When the hot water is discharged from the hot water tank, the hot water flows through the second common pipe 68 toward the mixing unit 72, and when the hot water heated by the power generation unit 21 is returned to the hot water tank 44, the hot water is the second common water. The pipe 68 flows toward the hot water tank 44.
[0021]
A power generation heat recovery pump 6 is disposed in the forward-only pipe 4 a 1 of the power generation heat recovery pipe 4. When the power generation heat recovery pump 6 is driven, hot water in the power generation heat recovery pipe 4 circulates (circulates in the direction of the arrow in the figure). The power generation heat recovery pump 6 is driven and controlled by the control unit 60.
Since the water supply thermistor T2 is disposed in the first common pipe 66, the water supply thermistor T2 can be used when detecting the temperature of the water in the forward pipe 4a of the power generation heat recovery pipe 4, and the hot water can be stored from the water supply pipe 64. It can also be used to detect the temperature of tap water when supplying tap water to the tank 44. Further, since the first hot water thermistor T1 is disposed in the second common pipe 68, it can also be used when detecting the temperature of the hot water in the return pipe 4b of the power generation heat recovery pipe 4, It can also be used to detect the temperature of hot water discharged from the hot water storage tank 44.
[0022]
Next, the heat source device 50 that performs the hot water supply operation and the heating operation will be described. The heat source device 50 is provided with two burners 38 and 56, a heating system 51, a plurality of pipes for guiding hot water and the like, and is housed in a heat source device housing 49.
First, the hot water supply operation will be described. The hot water supply pipe 94 connected to the second hot water discharge pipe 76 is branched into two branches, a pipe 94a and a pipe 94b, at a branching portion 94c. The end of the pipe 94 a is connected to a hot water supply location such as a kitchen faucet or a hot water tap of a bath, and the end of the pipe 94 b is placed in the upper part of the heating system turn 51.
The hot water supply temperature at the hot water supply point is set in advance by operating a remote controller (not shown). The pipe 94a is arranged so that the hot water in the pipe 94a is heated by the burner 38. The burner 38 is driven and controlled by the control unit 60. The pipe 94a is provided with a hot water supply amount sensor F1 and a hot water supply thermistor T6, which are used to detect the flow rate of hot water in the pipe 94a and the temperature of hot water to be supplied.
[0023]
A branch portion 94d is formed downstream of the burner 38 of the pipe 94a, and the hot water supply path 80 is branched from the branch portion 94d. This hot water supply path 80 is connected to a bathtub water circulation path 98 described later. A hot water supply valve 82 is provided in the hot water supply path 80. When the hot water supply valve 82 is opened, hot water is guided to the bathtub water circulation path 98 through the hot water supply path 80, and hot water is filled in the bathtub 90. Is done. The hot water supply valve 82 is controlled to be opened and closed by the control unit 60. The bathtub water circulation path 98 is provided with a hot water amount sensor F2 and a bathtub water thermistor T7, which are used to detect the flow rate and temperature of hot water in the bathtub water circulation path 98, respectively.
[0024]
Next, the heating operation will be described. A heating replenishing valve 95 is disposed on a pipe 94 b branched from the hot water supply pipe 94. When the heating water refill valve 95 is opened, hot water is guided to the heating system 51 through the pipe 94b. The heating water refill valve 95 is controlled to be opened and closed by the control unit 60 as follows.
A water level electrode 58 connected to the control unit 60 is disposed in the heating system 51. The water level electrode 58 includes a rod-shaped high level switch 58a and a low level switch 58b. The lower end of the high level switch 58 a is located at the upper limit of the water level of the heating systern 51, and the lower end of the low level switch 58 b is located at the lower limit of the water level of the heating systern 51. These high level switch 58a and low level switch 58b output an ON signal when the lower ends thereof are in contact with water.
The control unit 60 controls to open the heating water supplement valve 95 while the low level switch 58b does not output the ON signal, and closes the heating water supplement valve 95 when the high level switch 58a outputs the ON signal. To control. That is, the water level in the heating system 51 is maintained by the control unit 60 between the upper limit level and the lower limit level.
[0025]
A heating circuit is connected to the heating system 51. Specifically, the common pipe 2 is connected to the heating systern 51, and the heating pump 3 is disposed in the common pipe 2. The common pipe 2 is bifurcated to form a high temperature circuit 84 and a low temperature circuit 86. Hereinafter, a general term for the common pipe 2, the high-temperature circuit 84, and the low-temperature circuit 86 is a heating circuit.
The high-temperature circuit 84 includes a pipe 84 a that passes through a high-temperature load 92 (for example, a heater or a bathroom dryer) and a pipe 84 b that bypasses the high-temperature load 92. The pipe 84a sends the hot water in the heating cistern 51 to the high temperature load 92, and returns the used hot water to the heating cistern 51 (in the direction of the arrow in the figure). The return pipe of the pipe 84a joins a joining portion 86d formed in the return pipe of the low-temperature circulation path 86 described later. A thermal valve 85 is disposed on the pipe 84a. The thermal valve 85 opens when the operation switch of the high temperature load 92 is operated and is turned on, and is closed when the operation switch is turned off.
On the other hand, the pipe 84b is a pipe branched from a branch part 84c formed upstream of the thermal valve 85, and joins a junction part 86c formed in a return pipe of a low-temperature circulation path 86 described later. A heating bypass valve 83 is disposed on the pipe 84 b that bypasses the high temperature load 92. The heating bypass valve 83 is controlled to be opened and closed by the control unit 60.
[0026]
In order to heat the hot water in the high-temperature circuit 84, a burner 56 is disposed in the high-temperature circuit 84. The burner 56 is driven and controlled by the control unit 60. The temperature of hot water in the high-temperature circuit 84 is normally controlled to be about 80 ° C. A heating low temperature thermistor T8 is disposed upstream of the burner 56 of the high temperature circulation path 84 and is used to detect the temperature of hot water in the low temperature circulation path 86. A heating high temperature thermistor T9 is disposed downstream of the burner 56, and is used to detect the temperature of hot water in the high temperature water circulation path 84. The hot water in the high-temperature circulation path 84 circulates when the heating pump 3 is driven (circulates in the direction of the arrow in the figure). The heating pump 3 is driven and controlled by the control unit 60.
[0027]
A recirculation circuit 88 is connected to the high temperature circuit 84. A heat exchanger 91 is disposed in the recirculation circulation path 88, and merges with a confluence portion 86f formed in a return pipe of a low-temperature circulation path 86 described later. A heat valve 89 is disposed in the recirculation circuit 88. When the heat valve 89 is opened, hot water is guided from the high temperature circuit 84, and the heat of the hot water is transferred to the heat exchanger 91. It is. The thermal valve 89 is controlled to open and close by the control unit 60.
When chasing the bathtub water, the hot water in the bathtub 90 circulates in the bathtub water circulation path 98. The bathtub water circulation path 98 is disposed so as to pass through the heat exchanger 91 described above. Hot water in the bathtub water circulation path 98 circulates and is heated by the heat exchanger 91, so that the bathtub water is chased. The bathtub water circulation path 98 is provided with a bathtub water pump 99. When the bathtub water pump 99 is driven, hot water in the bathtub water circulation path 98 circulates. The bathtub water circulation pump 99 is driven and controlled by the control unit 60.
[0028]
The low-temperature circuit 86 is disposed so as to pass through a low-temperature load (floor heater or the like) 96. The low-temperature circuit 86 sends the hot water in the heating system 51 to the low-temperature load 96 and returns the hot water after use to the heating system 51 through two pipes to be described later.
A thermal valve 87 is provided in the forward pipe of the low-temperature circulation path 86. The thermal valve 87 is controlled to open and close by the control unit 60. Hot water in the low-temperature circuit 86 is normally controlled to be about 60 ° C.
[0029]
The return pipe of the low-temperature circulation path 86 includes a pipe 86 a that directly returns to the heating system 51 and a pipe 86 b that passes through the hot water storage tank 44 and returns to the heating system 51. These pipes 86 a and 86 b are switched by the three-way valve 12. The three-way valve 12 has one inlet 12a and two outlets 12b and 12c. The return pipe of the low-temperature circulation path 86 is connected to the inlet 12 a of the three-way valve 12. A pipe 86 a is connected to the outlet 12 b of the three-way valve 12. The other end of the pipe 86 a is connected to the heating systern 51. On the other hand, a pipe 86 b is connected to the outlet 12 c of the three-way valve 12. This pipe 86 b is a pipe that passes through the upper part of the hot water tank 44 without being mixed with the hot water in the hot water tank 44. After passing through the hot water storage tank 44, the pipe 86b joins the joining part 86e of the pipe 86a. Switching of the three-way valve 12 is controlled by the control unit 60. The hot water in the low-temperature circulation path 86 is also circulated by driving the heating pump 3 (circulates in the direction of the arrow in the figure). A heating return thermistor T10 is disposed between the junction 86c of the return pipe of the low-temperature circuit 86 and the three-way valve 12, and is used to detect the temperature of hot water in the return pipe of the low-temperature circuit 86. The
[0030]
The heat stored in the hot water tank 44 can be used for the heating operation by the pipe 86b described above. When it is desired to use the heat in the hot water storage tank 44 for the floor heating operation, the outlet of the three-way valve 12 is switched to the outlet 12c. When the hot water in the pipe 86 b passes through the upper part of the hot water storage tank 44, it is heated by the hot hot water in the upper part of the hot water storage tank 44, and the heated hot water returns to the systern 51. The hot water in the low-temperature circuit 86 is heated by this circulation, and the heat of the hot water is transferred to the floor heater that is the low-temperature load 96. If it does in this way, the heat in hot water storage tank 44 can be used for heating operations, such as floor heating operation.
When the amount of heat stored in the hot water storage tank 44 has been released, the heating bypass valve 83 is opened to open the pipe 84b that bypasses the high temperature load 92 (in this case, the bathroom dryer). In this case, the high-temperature water heated by the burner 56 is guided to the cistern 51, and the heating operation can be performed using the high-temperature hot water.
[0031]
Further, by the above-described pipe 86b, after the heating operation is completed, the remaining heat in the heating circulation path can be stored in the hot water tank 44 when the amount of heat stored in the hot water tank 44 is small. When the temperature of the upper part of the hot water tank 44 is lower than the temperature of the hot water in the low-temperature circuit 86, the outlet of the three-way valve 12 is switched to the outlet 12c. As a result, hot water in the low-temperature circuit 86 is guided to the pipe 86b. When the hot water in the pipe 86b passes through the hot water storage tank 44, the hot water in the hot water storage tank 44 is heated. In this way, the residual heat in the heating circuit such as the low-temperature circuit 86 can be stored in the hot water tank 44.
[0032]
Next, a hot water supply operation and a heat storage operation (power generation operation) performed using the first common pipe 66 and the second common pipe 68 will be described in detail with reference to FIGS. 2 to 4 are schematic views of the cogeneration system 10 shown in FIG. 1, and the pipes indicated by solid lines indicate that hot water is circulating, and the pipes indicated by dotted lines are This indicates that the circulation of hot water is stopped.
FIG. 2 is a schematic diagram showing the flow of hot water when the power generation operation is stopped and only the hot water supply operation is performed in the cogeneration system 10 of the present embodiment. When a hot water tap or the like is opened at the hot water use point 40, tap water is supplied from the water supply pipe 64 and enters the first common pipe 66 from the branch part 64d. The tap water flows in the first common pipe 66 in the direction of the arrow in the figure and flows into the hot water storage tank 44. If the inlet 72b of the mixing unit 72 is open, the tap water enters the second water supply pipe 64b from the branch portion 64c and mixes. It also flows into the unit 72. At this time, since the power generation operation is stopped and the power generation heat recovery pump 6 is not driven, the supplied tap water enters from the branching portion 64d into the forward dedicated pipe 4a1 of the power generation heat recovery pipe 4. There is no.
[0033]
Hot water in the hot water storage tank 44 flows from the upper part of the hot water storage tank 44 through the second common pipe 68 in the direction of the arrow in the figure, and flows into the mixing unit 72 from the inlet 72a of the mixing unit 72 via the junction 52a. Also at this time, since the power generation heat recovery pump 6 is not driven, the hot water in the return dedicated pipe 4b1 of the power generation heat recovery pipe 4 does not enter the first hot water discharge pipe 52 from the junction 52a.
Hot water mixed in the mixing unit 72 flows into the heat source unit 50 from the outlet 72c through the second hot water discharge pipe 76, and is heated by the burner 38 while passing through the hot water supply pipe 94a if the temperature is lower than the set temperature. . Hot water of a set temperature is supplied to the hot water use location 40 through the hot water supply pipe 94a.
Since the power generation heat recovery pump 6 is not driven, the hot water in the forward dedicated pipe 4a1 and the return dedicated pipe 4b1 of the power generation heat recovery pipe 4 does not flow.
[0034]
FIG. 3 is a schematic diagram showing the flow of hot water when hot water supply is stopped and only the heat storage operation (power generation operation) is performed in the cogeneration system 10 of the present embodiment.
When the power generation heat recovery pump 6 is driven, the hot water in the hot water storage tank 44 flows from the lower part of the hot water storage tank 44 in the first common pipe 66 in the direction of the arrow in the figure. This direction is opposite to that when the first shared pipe 66 is used as a water supply pipe (see FIG. 2). Since the hot water supply operation is stopped and the hot water tap or the like of the hot water use point 40 is not opened, it does not enter the second water supply pipe 64b from the branch part 64c.
The hot water in the first common pipe 66 flows from the branch part 64d into the forward dedicated pipe 4a1 of the power generation heat recovery pipe 4. The water supply pipe 64 is provided with a pressure reducing valve (42: see FIG. 1), so that hot water in the first common pipe 66 does not flow backward from the branch portion 64d toward the water supply port.
[0035]
The water in the forward dedicated pipe 4a1 of the power generation heat recovery pipe 4 flows in the direction of the arrow in the figure and flows into the power generation unit 20 to recover the power generation heat in the power generation unit 20. The hot water heated by the generated heat flows in the return dedicated pipe 4b1 of the generated heat recovery pipe 4 in the direction of the arrow in the figure, and joins from the junction 52a into the second shared pipe 68. Also at this time, since the hot water tap or the like of the hot water utilization point 40 is not opened, the hot water tap 40 does not enter the first hot water discharge pipe 52 from the junction 52a and flow to the mixing unit 72 side.
Hot water in the second common pipe 68 flows in the direction of the arrow in the drawing and flows into the hot water tank 44 from the upper part of the hot water tank 44. This direction is opposite to that when the second common pipe 68 is used as a hot water outlet pipe (see FIG. 2).
[0036]
As described above, in the cogeneration system 10 of the present embodiment, the first common pipe 66 serves as both the water supply pipe 64 and the forward pipe 4 a of the power generation heat recovery pipe 4. Further, the second common pipe 68 also serves as the first hot water discharge pipe 52 and the return pipe 4b of the power generation heat recovery pipe 4. For this reason, two pipes near the hot water storage tank 44 can be reduced, and the space inside the heat storage unit housing 16 can be saved. This makes it possible to increase the size of the hot water storage tank 44 without increasing the size of the entire system. Alternatively, it is possible to reduce the size of the entire system without reducing the heat storage amount.
[0037]
In a normal cogeneration system, the return pipe of the heat generation heat recovery pipe is connected to the upper part of the hot water tank. For this reason, the hot water heated by the generated heat flows into the upper part of the hot water storage tank from the return pipe of the generated heat recovery pipe, and the temperature of the hot water in the upper part of the hot water tank increases. On the other hand, the forward pipe of the power generation heat recovery pipe is connected to the lower part of the hot water storage tank so as to recover the generated heat efficiently by sending water as low as possible to the power generation unit. By continuing the heat storage operation (power generation operation), a temperature gradient from high temperature to low temperature is formed in the hot water tank from the top to the bottom.
The 1st hot water pipe which discharges hot water from a hot water tank is connected to the upper part of a hot water tank so that hot water as hot as possible can be discharged. Moreover, the 1st water supply pipe which supplies tap water to a hot water storage tank is connected to the lower part of a hot water tank so that the temperature of the hot water of high temperature may be reduced as much as possible. That is, the feed water pipe and the forward pipe for generating heat recovery are both low-temperature water pipes, and both the tapping pipe and the return pipe for generating heat recovery are high-temperature hot water pipes.
For this reason, in the cogeneration system 10 of the present embodiment, the first common pipe 66 is connected to the lower part of the hot water tank 44, and the first common pipe 66 is connected to the water supply pipe and the outgoing pipe of the power generation heat recovery pipe 4 ( 4a: see FIG. 1), the second common pipe 68 is connected to the upper part of the hot water storage tank 44, and the hot water pipe and the return pipe (4b: see FIG. 1) of the power generation heat recovery pipe 4 share. be able to.
[0038]
FIG. 4 is a schematic diagram showing the flow of hot water when the hot water supply operation and the heat storage operation (power generation operation) are performed simultaneously in the cogeneration system 10 of the present embodiment.
First, the hot water supply operation will be described. When the hot water supply operation is performed, hot water flows in a pipe exactly the same as the pipe described above with reference to FIG. That is, when a hot water tap or the like is opened at the hot water use point 40, tap water is supplied from the water supply pipe 64, enters the first common pipe 66 from the branch part 64d, flows into the hot water tank 44, and is mixed with the mixing unit 72. If the inlet 72b is open, it enters the second water supply pipe 64b and flows into the mixing unit 72. Hot water in the hot water storage tank 44 flows in the second common pipe 68 in the direction of the arrow in the figure, and flows into the mixing unit 72. The hot water mixed by the mixing unit 72 flows into the heat source unit 50 through the second hot water outlet pipe 76, and is supplied to the hot water use point 40 through the hot water supply pipe 94a in which the burner 38 is disposed.
[0039]
At this time, a heat storage operation (power generation operation) is also performed. In the first common pipe 66, the supplied tap water flows in the direction of the arrow in the figure due to the tap water pressure (depressurized), and this direction is the forward pipe of the power generation heat recovery pipe 4 shown in FIG. (4a: refer to FIG. 1) The flow is in the opposite direction. Therefore, even if the power generation heat recovery pump 6 is driven, the hot water in the hot water storage tank 44 cannot flow back through the first common pipe 66 and flow into the forward-only pipe 4 a 1 of the power generation heat recovery pipe 4. When the power generation heat recovery pump 6 is driven, the tap water supplied to the water supply pipe 64 branches from the branching section 64d and flows into the dedicated forward pipe 4a1 of the power generation heat recovery pipe 4.
[0040]
The tap water that has flowed into the outgoing special pipe 4a1 of the power generation heat recovery pipe 4 flows in the direction of the arrow in the figure and flows into the power generation unit 20 to recover the generated heat. The hot water heated by the generated heat flows in the return dedicated pipe 4b1 of the generated heat recovery pipe 4 in the direction of the arrow in the figure. At this time, hot water discharged from the hot water storage tank 44 flows in the second common pipe 68 in the direction of the arrow in the figure due to the tap water pressure (reduced pressure), and this direction is the recovery of the generated heat shown in FIG. This is in the opposite direction to the flow in the return pipe (4b: see FIG. 1) of the pipe 4 for operation. Therefore, the hot water in the return dedicated pipe 4 b 1 cannot flow back into the hot water storage tank 44 from the junction 52 a of the first hot water pipe 52 through the second shared pipe 68. When the power generation heat recovery pump 6 is driven, the hot water in the return dedicated pipe 4b1 of the power generation heat recovery pipe 4 joins the hot water from the second common pipe 68 at the junction 52a and flows into the first outlet pipe 52. Then, it enters the mixing unit 72 and is used for hot water supply.
[0041]
As described above, when the hot water supply operation and the heat storage operation (power generation operation) are performed simultaneously, the flow of hot water in the hot water supply pipe during the hot water supply operation is in the same direction as that shown in FIG. 2, but the heat storage operation (power generation operation). The flow of hot water in the internal power generation heat recovery pipe 4 is in the direction opposite to the direction shown in FIG. That is, the heat generating heat recovery pipe 4 is not a pipe passing through the hot water storage tank 44, but the forward pipe (4a: see FIG. 1) is a pipe for directly feeding the supplied tap water to the power generation unit 20, and a return pipe (4b : Refer to FIG. 1) is a pipe for directly sending hot water heated by the generated heat to the mixing unit 72. By using low-temperature tap water, the generated heat can be efficiently recovered, and hot water hotter than hot water in the hot water storage tank 44 can be efficiently used for hot water supply.
[0042]
The cogeneration system 10 described above includes the two shared pipes 66 and 68. However, in order to implement the present invention, any one of these shared pipes 66 and 68 may be provided. .
The cogeneration system 110 according to the second embodiment includes only the shared pipe 166 corresponding to the first shared pipe 66 and does not have the second shared pipe. A second embodiment will be described with reference to FIGS. 5 to 7 are diagrams schematically illustrating the cogeneration system 110 according to the present embodiment. The pipes indicated by solid lines indicate that hot water is circulating, and the pipes indicated by dotted lines are hot water. Indicates that the distribution of is stopped.
The common pipe 166 disposed in the cogeneration system 110 according to the present embodiment is exactly the same as the first common pipe 66 of the cogeneration system 10 according to the first embodiment. Shared to the tube. However, the cogeneration system 110 does not include a shared pipe corresponding to the second shared pipe 68 of the first embodiment. That is, the first hot water discharge pipe 152 and the return dedicated pipe 104b1 of the power generation heat recovery pipe 104 are independent pipes. The first hot water discharge pipe 152 is a pipe connecting the upper part of the hot water storage tank 44 and the inlet 72a of the mixing unit 72, and the return dedicated pipe 104b1 is a pipe connecting the power generation unit 20 and the upper part of the hot water storage tank 44 (FIG. 7). reference).
[0043]
A hot water supply operation and a heat storage operation (power generation operation) performed using the common pipe 166 will be described. FIG. 5 is a schematic diagram showing the flow of hot water when the power generation operation is stopped and only the hot water supply operation is performed in the cogeneration system 110 of the present embodiment. When a hot water tap or the like is opened at the hot water usage point 40, tap water is supplied from the water supply pipe 64 and enters the common pipe 166 from the branch part 64d. The tap water flows in the common pipe 166 in the direction of the arrow in the drawing and flows into the hot water storage tank 44. If the inlet 72b of the mixing unit 72 is open, the tap water enters the second water supply pipe 64b from the branch portion 64c. It also flows in. At this time, since the power generation operation is stopped and the power generation heat recovery pump 6 is not driven, the supplied tap water enters the forward dedicated pipe 104a1 of the power generation heat recovery pipe 4 from the branch portion 64d. There is no.
[0044]
Hot water in the hot water storage tank 44 flows from the upper part of the hot water storage tank 44 through the first hot water discharge pipe 152 in the direction of the arrow in the figure, and flows into the mixing unit 72 from the inlet 72a of the mixing unit 72. Hot water mixed in the mixing unit 72 flows into the heat source unit 50 from the outlet 72c through the second hot water discharge pipe 76, and is heated by the burner 38 while passing through the hot water supply pipe 94a if the temperature is lower than the set temperature. . Hot water of a set temperature is supplied to the hot water use location 40 through the hot water supply pipe 94a.
At this time, since the power generation heat recovery pump 6 is not driven, the hot water in the forward dedicated pipe 104a1 and the hot water in the return dedicated pipe 104b1 do not flow.
[0045]
FIG. 6 is a schematic diagram showing the flow of hot water when hot water supply is stopped and only the heat storage operation (power generation operation) is performed in the cogeneration system 110 of the present embodiment.
When the power generation heat recovery pump 6 is driven, the hot water in the hot water storage tank 44 flows from the lower part of the hot water storage tank 44 through the common pipe 166 in the direction of the arrow in the figure. This direction is opposite to that when the common pipe 166 is used as a water supply pipe (see FIG. 5). At this time, the hot water supply operation is stopped, and the hot water tap or the like of the hot water use point 40 is not opened, so that it does not enter the second water supply pipe 64b from the branch part 64c.
The hot water in the shared pipe 166 flows from the branching section 64d into the dedicated forward pipe 104a1 of the power generation heat recovery pipe 104. The water supply pipe 64 is provided with a pressure reducing valve (42: see FIG. 1), so that hot water in the common pipe 166 does not flow backward from the branch portion 64d toward the water supply port.
[0046]
The hot water in the forward dedicated pipe 104a1 of the power generation heat recovery pipe 104 flows in the direction of the arrow in the figure and flows into the power generation unit 20 to recover the power generation heat in the power generation unit 20. The hot water heated by the generated heat flows in the return dedicated pipe 104b1 of the generated heat recovery pipe 104 in the direction of the arrow in the figure, and flows into the hot water tank 44 from the upper part of the hot water tank 44. At this time, since the hot water tap or the like of the hot water use point 40 is not opened, hot water in the hot water supply pipe does not flow.
[0047]
As described above, in the cogeneration system 110 of the present embodiment, the common pipe 166 is used as the forward pipe of the water supply pipe and the power generation heat recovery pipe 104. For this reason, one piping near the hot water tank 44 can be reduced, and the space inside the heat storage unit housing 16 can be saved. This makes it possible to increase the size of the hot water storage tank 44 without increasing the size of the entire system. Alternatively, it is possible to reduce the size of the entire system without reducing the heat storage amount.
[0048]
FIG. 7 is a schematic diagram showing the flow of hot water when the hot water supply operation and the heat storage operation (power generation operation) are performed simultaneously in the cogeneration system 110 of the present embodiment.
First, the hot water supply operation will be described. When the hot water supply operation is performed, hot water flows through the pipe exactly the same as the pipe described above with reference to FIG. That is, when a hot water tap or the like is opened at the hot water use point 40, tap water is supplied from the water supply pipe 64 and enters the common pipe 166 through the branch part 64d and flows into the hot water storage tank 44, and also at the entrance of the mixing unit 72. If 72b is open, it enters the second water supply pipe 64b and flows into the mixing unit 72 as well. Hot water in the hot water storage tank 44 flows in the first hot water discharge pipe 152 in the direction of the arrow in the figure, and flows into the mixing unit 72. The hot water mixed by the mixing unit 72 flows into the heat source unit 50 through the second hot water outlet pipe 76, and is supplied to the hot water use point 40 through the hot water supply pipe 94a in which the burner 38 is disposed.
[0049]
At this time, a heat storage operation (power generation operation) is also performed. In the common pipe 166, the supplied tap water flows in the direction of the arrow in the figure due to the tap water pressure (depressurized), and this direction is the flow in the forward pipe of the power generation heat recovery pipe 104 shown in FIG. And in the opposite direction. Therefore, even if the power generation heat recovery pump 6 is driven, the hot water in the hot water storage tank 44 cannot flow back through the common pipe 166 and flow into the forward dedicated pipe 104 a 1 of the power generation heat recovery pipe 104. When the power generation heat recovery pump 6 is driven, the tap water supplied to the water supply pipe 64 is branched from the branch portion 64d and flows into the forward dedicated pipe 104a1 of the power generation heat recovery pipe 104.
[0050]
The tap water that has flown into the forward dedicated pipe 104a1 of the power generation heat recovery pipe 104 flows in the direction of the arrow in the figure and flows into the power generation unit 20 to recover the generated heat. The hot water heated by the generated heat flows in the return dedicated pipe 104b1 of the generated heat recovery pipe 104 in the direction of the arrow in the figure. The hot water in the return dedicated pipe 104b1 of the power generation heat recovery pipe 104 enters the hot water storage tank 44 and is used for hot water supply.
[0051]
As described above, when the hot water supply operation and the heat storage operation (power generation operation) are performed simultaneously, the flow of hot water in the hot water supply pipe during the hot water supply operation is in the same direction as that shown in FIG. 5, but the heat storage operation (power generation operation). The flow of hot water in the forward pipe of the internal power generation heat recovery pipe 104 is opposite to the direction shown in FIG. In other words, the forward pipe of the power generation heat recovery pipe 104 is not a pipe from the hot water storage tank 44 but a pipe that feeds the supplied tap water directly to the power generation unit 20. By using low-temperature tap water, the generated heat can be efficiently recovered and stored efficiently.
[0052]
Next, as a third embodiment, a cogeneration system 210 having a shared pipe 268 corresponding to the second shared pipe 68 of the cogeneration system 10 of the first embodiment and having no first shared pipe will be described with reference to FIGS. 10 will be used for explanation. FIGS. 8 to 10 are diagrams schematically illustrating the cogeneration system 210 of the present embodiment. The pipes indicated by solid lines indicate that hot water is circulating, and the pipes indicated by dotted lines are hot water. Indicates that the distribution of is stopped.
The common pipe 268 provided in the cogeneration system 210 of this embodiment is exactly the same as the second common pipe 68 of the cogeneration system 10 of the first embodiment, and the return of the hot water pipe and the power generation heat recovery pipe 204 is the same. Shared to the tube. However, the cogeneration system 210 does not include a shared pipe corresponding to the first shared pipe 66 of the first embodiment. That is, the feed water pipe 64 and the forward pipe 204a1 of the power generation heat recovery pipe 204 are independent pipes. The 1st water supply pipe 64a is piping connected with the lower part of the hot water storage tank 44, and the going-out exclusive pipe 204a1 is piping which connects the lower part of the hot water storage tank 44 and the electric power generation unit 20 (refer FIG. 10).
[0053]
A hot water supply operation and a heat storage operation (power generation operation) performed using the common pipe 268 will be described. FIG. 8 is a schematic diagram showing the flow of hot water when the power generation operation is stopped and only the hot water supply operation is performed in the cogeneration system 210 of the present embodiment. When a hot water tap or the like is opened at the hot water use point 40, tap water is supplied and enters the water supply pipe 64. The tap water flows in the direction of the arrow in the water supply pipe 64 and flows into the hot water storage tank 44. In addition, if the inlet 72b of the mixing unit 72 is open, the tap water enters the second water supply pipe 64b from the branch portion 64c. It also flows in.
[0054]
Hot water in the hot water storage tank 44 flows in the shared pipe 268 from the upper part of the hot water storage tank 44 in the direction of the arrow in the figure, and flows into the mixing unit 72 from the inlet 72a of the mixing unit 72 via the junction 252a. At this time, since the power generation heat recovery pump 6 is not driven, the hot water in the return dedicated pipe 204b1 of the power generation heat recovery pipe 204 does not enter the first outlet pipe 252 from the junction 252a.
Hot water mixed in the mixing unit 72 flows into the heat source unit 50 from the outlet 72c through the second hot water discharge pipe 76, and is heated by the burner 38 while passing through the hot water supply pipe 94a if the temperature is lower than the set temperature. . Hot water of a set temperature is supplied to the hot water use location 40 through the hot water supply pipe 94a.
[0055]
FIG. 9 is a schematic diagram showing the flow of hot water when hot water supply is stopped and only the heat storage operation (power generation operation) is performed in the cogeneration system 210 of the present embodiment.
When the power generation heat recovery pump 6 is driven, the hot water in the hot water storage tank 44 flows into the power generation unit 20 from the lower part of the hot water storage tank 44 through the forward dedicated pipe 204a1 of the power generation heat recovery pipe 204 in the direction of the arrow in the figure. To recover the heat generated. The hot water heated by the generated heat flows in the return dedicated pipe 204b1 of the generated heat recovery pipe 204 in the direction of the arrow in the figure, and joins from the junction 252a of the first outlet pipe 252 into the shared pipe 268. At this time, since the hot water tap or the like of the hot water use point 40 is not opened, the hot water tap 40 does not enter the first hot water discharge pipe 252 from the junction 252a and flow to the mixing unit 72 side.
Hot water in the common pipe 268 flows in the direction of the arrow in the figure and flows into the hot water tank 44 from the upper part of the hot water tank 44. Note that this direction is opposite to the direction when the common pipe 268 is used as a tapping pipe (see FIG. 8).
[0056]
FIG. 10 is a schematic diagram showing the flow of hot water when the hot water supply operation and the heat storage operation (power generation operation) are simultaneously performed in the cogeneration system 210 of the present embodiment.
First, the hot water supply operation will be described. When the hot water supply operation is performed, hot water flows in the pipe exactly the same as the pipe described above with reference to FIG. That is, when a hot water tap or the like is opened at the hot water use point 40, tap water is supplied from the water supply pipe 64 and flows into the hot water storage tank 44, and if the inlet 72b of the mixing unit 72 is open, the second water supply pipe 64b. Enters the mixing unit 72. Hot water in the hot water storage tank 44 flows in the common pipe 268 in the direction of the arrow in the figure, and flows into the mixing unit 72. The hot water mixed by the mixing unit 72 flows into the heat source unit 50 through the second hot water outlet pipe 76, and is supplied to the hot water use point 40 through the hot water supply pipe 94a in which the burner 38 is disposed.
[0057]
At this time, a heat storage operation (power generation operation) is also performed. When the power generation heat recovery pump 6 is driven, the hot water in the hot water storage tank 44 flows into the forward dedicated pipe 204 a 1 of the power generation heat recovery pipe 204. The hot water that has flowed into the outgoing dedicated pipe 204a1 flows in the direction of the arrow in the figure, flows into the power generation unit 20, and recovers the heat generated in the power generation unit 20. The hot water heated by the generated heat flows in the return dedicated pipe 204b1 of the generated heat recovery pipe 204 in the direction of the arrow in the figure. At this time, hot water discharged from the hot water storage tank 44 flows in the common pipe 268 in the direction of the arrow in the figure due to the tap water pressure (depressurized), and this direction is the pipe for generating heat recovery shown in FIG. It is in the opposite direction to the flow of 204 return pipe. Accordingly, the hot water in the return dedicated pipe 204 b 1 cannot flow back into the hot water storage tank 44 through the common pipe 268 from the junction 252 a of the first hot water discharge pipe 252. When the power generation heat recovery pump 6 is driven, the hot water in the return dedicated pipe 204b1 of the power generation heat recovery pipe 204 merges with the hot water from the common pipe 268 at the junction 252a and flows into the first outlet pipe 252 to be mixed. Enters 72 and is used for hot water supply.
[0058]
As described above, when the hot water supply operation and the heat storage operation (power generation operation) are performed simultaneously, the flow of hot water in the hot water supply pipe during the hot water supply operation is in the same direction as that shown in FIG. 8, but the heat storage operation (power generation operation). The flow of hot water in the return pipe of the power generation heat recovery pipe 204 inside is in the direction opposite to the direction shown in FIG. That is, the return pipe of the power generation heat recovery pipe 204 is not a pipe that is sent into the hot water storage tank 44 but a pipe that sends hot water heated by the generated heat directly to the mixing unit 72. Although heat cannot be stored in the hot water tank 44, hot water can be sent directly to the mixing unit 72, so that the hot water in the hot water tank 44 can be efficiently used for hot water supply.
[0059]
As described above, in the cogeneration system 210 of the present embodiment, the common pipe 268 is used as the return pipe of the hot water pipe and the power generation heat recovery pipe 204. For this reason, one piping near the hot water tank 44 can be reduced, and the space inside the heat storage unit housing 16 can be saved. This makes it possible to increase the size of the hot water storage tank 44 without increasing the size of the entire system. Alternatively, it is possible to reduce the size of the entire system without reducing the heat storage amount.
[0060]
In the cogeneration system of the present invention, a single pipe is shared by two paths, so that the limited space in the housing can be used effectively. As a result, the hot water storage tank is enlarged to increase the amount of stored hot water (heat storage amount). ) Or the entire system can be reduced in size.
The second common pipe 68 disposed in the cogeneration system 10 of the first embodiment and the common pipe 268 disposed in the cogeneration system 210 of the third embodiment are stored in the hot water storage tank 44 during hot water supply. It functions as a hot water outlet pipe that has been heated, and functions as a return pipe for hot water heated by the generated heat during hot water supply stop and heat storage operation (power generation operation). For this reason, at any time, relatively high-temperature hot water flows in the shared pipes 68 and 268, and the temperature corresponds to the temperature of the upper part of the hot water tank 44. Therefore, the shared pipes 68 and 268 can function as a second hot water storage tank. The amount of stored hot water (heat storage amount) of the entire system can be increased without increasing the size of the entire system or the size of the hot water storage tank.
[0061]
Further, in the cogeneration system of the present invention, when the amount of stored heat in the hot water storage tank 44 runs out (running out of hot water), the first hot water thermistor T1 detects the temperature change of the hot water. When this signal is transmitted to the control unit 60, the burner 38 of the heat source device 50 is ignited to heat and supply hot water in the hot water supply pipe 94a. At this time, a time lag of about 15 seconds occurs after the hot water is detected until the burner 38 is ignited. In the conventional technology, the temperature of the hot water supplied from the hot water use point 40 during this time greatly fluctuates, which may give the user discomfort. However, in the cogeneration systems 10 and 210, if the diameters of the shared pipes 68 and 268 are increased, it is possible to store about 2 liters of hot water in the shared pipes 68 and 268. As a result, the hot water in the common pipes 68 and 268 is supplied from the first hot water thermistor T1 disposed in the vicinity of the connecting portion with the hot water tank 44 until the burner 38 is ignited until the hot water in the shared pipes 68 and 268 is heated. It flows into 94a. For this reason, the hot water temperature fluctuation at the time of running out of water is absorbed, and the user can use it without feeling uncomfortable.
[0062]
Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a cogeneration system according to a first embodiment.
FIG. 2 is a schematic diagram showing the flow of hot water during hot water supply in the first embodiment.
FIG. 3 is a schematic view showing a flow of hot water during a heat storage operation (power generation operation) in the first embodiment.
FIG. 4 is a schematic diagram showing the flow of hot water during hot water supply and heat storage operation (power generation operation) in the first embodiment.
FIG. 5 is a schematic diagram showing the flow of hot water during hot water supply in the second embodiment.
FIG. 6 is a schematic diagram showing a flow of hot water during a heat storage operation (power generation operation) in the second embodiment.
FIG. 7 is a schematic diagram showing the flow of hot water during hot water supply and heat storage operation (power generation operation) in the second embodiment.
FIG. 8 is a schematic diagram showing the flow of hot water during hot water supply in the third embodiment.
FIG. 9 is a schematic diagram showing the flow of hot water during a heat storage operation (power generation operation) in the third embodiment.
FIG. 10 is a schematic diagram showing the flow of hot water during hot water supply and heat storage operation (power generation operation) in the third embodiment.
[Explanation of symbols]
3: Heating pump
4: Piping for generating heat recovery 4a: Outward pipe, 4b: Return pipe, 4a1: Outward pipe, 4b1: Return pipe
6: Pump for heat recovery
10: Cogeneration system (first embodiment)
12: Three-way valve, 12a: Inlet, 12b: Outlet, 12c: Outlet
15: Thermal storage unit
16: Heat storage unit housing
20: Power generation unit
21: Power generation unit housing
22: Fuel cell
24: Heat medium circulation pipe
25: Sisturn
28: Radiator
30: Reformer
32: Burner
34: Fuel gas exhaust pipe
36: Three-way valve
38: Burner
40: Use of hot water
42: Pressure reducing valve
44: Hot water storage tank
46: Relief valve
49: Heat source machine housing
50: Hot water heater / heat source machine
51: Sistern for heating
52: 1st tap pipe, 52a: Junction
53: Drain valve
54: Drain pipe
55: Drainage piping
56: Burner
58: Water level electrode, 58a: High level switch, 58b: Low level switch
60: Control unit
64: Water supply pipe, 64a: 1st water supply pipe, 64b: 2nd water supply pipe, 64c: Branch part, 64d: Branch part
66: First common pipe
68: Second common pipe
70: Heat exchanger
72: mixing unit, 72a: inlet, 72b: inlet, 72c: outlet
74: Heat exchanger
76: Second hot spring pipe
80: Hot water supply channel
82: Hot water supply valve
83: Bypass valve for heating
84: High-temperature circuit, 84a: Pipe, 84b: Pipe, 84c: Branch
85: Thermal valve
86: Circuit for low temperature, 86a: Pipe, 86b: Pipe, 86c: Merge part, 86d: Merge part, 86e: Merge part, 86f: Merge part
87: Thermal valve
88: Remembrance circuit
89: Thermal valve
90: Bathtub
91: Heat exchanger
92: High temperature load
94: Hot water supply pipe, 94a: Pipe, 94b: Pipe, 94c: Branch part, 94d: Branch part
95: Replenishment valve for heating
96: Low temperature load
98: Bathtub water circuit
99: Pump for bathtub water
104: Piping for heat recovery, 104a1: Outward pipe, 104b1: Return pipe
110: Cogeneration system (second embodiment)
210: Cogeneration system (third embodiment)

Claims (7)

A power generation unit, a hot water storage tank, a water supply pipe for supplying tap water to the hot water storage tank, a forward pipe for sending water in the hot water storage tank to the power generation unit, a return pipe for sending hot water heated by the generated heat to the hot water storage tank , A cogeneration system with a thermistor ,
The forward pipe is also connected to the power generation unit by branching from the water supply pipe, which also serves as a part of the water supply pipe ,
The thermistor is provided between the branch portion where the outgoing pipe branches from the water supply pipe and the hot water storage tank, and is provided in a portion that serves as both the water supply pipe and the outgoing pipe, and the temperature of the tap water supplied to the hot water storage tank and A cogeneration system that measures the temperature of the water sent from the hot water tank to the power generation unit .   The part that is located between the branch where the forward pipe branches off from the water supply pipe and the hot water storage tank and serves as the water supply pipe and the forward pipe functions as a water supply pipe during hot water supply operation while power generation is stopped, and power generation operation when hot water supply is stopped The cogeneration system according to claim 1, wherein the cogeneration system functions as a forward pipe.   It further comprises a mixing unit that mixes hot water and tap water, and a hot water pipe that sends hot water in the hot water tank to the mixing unit.
  The water supply pipe has a first water supply pipe and a second water supply pipe that are bifurcated, the first water supply pipe is connected to a hot water storage tank, and the second water supply pipe is connected to a mixing unit,
3. The cogeneration system according to claim 1, wherein the thermistor is provided between a branch portion where the first water supply pipe and the second water supply pipe branch and a branch portion where the forward pipe branches from the water supply pipe. .   A power generation unit, a hot water tank, a mixing unit that mixes hot water and tap water, a hot water pipe that sends hot water in the hot water tank to the mixing unit, a water supply pipe that supplies tap water to the hot water tank and the mixing unit, and hot water storage A cogeneration system comprising a forward pipe for sending water in the tank to the power generation unit, a return pipe for sending hot water heated by the generated heat to the hot water storage tank, and a thermistor;
  The return pipe is connected to a hot water storage tank through a hot water pipe,
  The thermistor is provided between the hot water storage tank and the junction where the hot water pipe and the return pipe join together, and the temperature of the hot water sent from the hot water tank to the mixing unit. And a cogeneration system for measuring the temperature of the hot water sent from the power generation unit to the hot water storage tank.   The portion that is located between the junction where the tapping pipe and return pipe join together and the hot water storage tank functions as the tapping pipe and return pipe functions as a tapping pipe during hot water supply operation while power generation is stopped, and power generation operation when hot water is stopped The cogeneration system according to claim 4, wherein the cogeneration system functions as a return pipe.   A power generation unit, a hot water tank, a mixing unit that mixes hot water and tap water, a hot water pipe that sends hot water in the hot water tank to the mixing unit, a water supply pipe that supplies tap water to the hot water tank and the mixing unit, and hot water storage A cogeneration system comprising an outgoing pipe for sending water in the tank to the power generation unit, a return pipe for sending hot water heated by the generated heat to the hot water storage tank, a first thermistor, and a second thermistor;
  The forward pipe is also connected to the power generation unit by branching from the water supply pipe and also serving as a part of the water supply pipe.
  The first thermistor is provided between a branch portion where the outgoing pipe branches from the water supply pipe and a hot water storage tank, and is provided in a portion serving as both the water supply pipe and the outgoing pipe, and the tap water supplied to the hot water storage tank is provided. Measuring the temperature and the temperature of the water sent from the hot water tank to the power generation unit,
  The return pipe is connected to a hot water storage tank through a hot water pipe,
  The second thermistor is provided between a hot water storage tank and a junction where the hot water discharge pipe and the return pipe merge, and the hot water supplied from the hot water storage tank to the mixing unit. And a temperature of the hot water sent from the power generation unit to the hot water tank.   The water supply pipe has a first water supply pipe and a second water supply pipe that are bifurcated, the first water supply pipe is connected to a hot water storage tank, and the second water supply pipe is connected to a mixing unit,
The cogeneration system according to claim 6, wherein the first thermistor is provided between a branch portion where the first water supply pipe and the second water supply pipe branch and a branch portion where the forward pipe branches from the water supply pipe. .

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