JP5333847B2 - Cogeneration system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop a structure having functions of bath reheating and supplying heat to a floor heating device or the like other than hot water supply, and having a smaller number of parts in comparison with a conventional product in a cogeneration system using a fuel cell. <P>SOLUTION: An exhaust heat recovery circulation passage 7, a heat using recirculation passage 8, a hot water supply passage 9 are connected by a heat recovery-using first short passage 35, a heat recovery-heat using second short passage 17, a water supply short passage 18, and a high temperature hot water short passage 19. An on/off-valve 34 is provided in the high temperature hot water short passage 19. An opening c of a three-way valve 28 is in an end of the water supply short passage 18. The heat recovery-heat using second short passage 17 is connected to the opening c of the three-way valve 26. Even though a valve does not exist in the heat recovery-heat using first short passage 35, there is no circulation of hot and cold water y pressure balance. By this, a storage formed by storing hot and cold water in a storage tank 10, a hot water supply mode of carrying out hot water supply by only hot water in the tank, and a heating reheating mode can be carried out at the same time. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a cogeneration system using a fuel cell.

Cogeneration systems that use hot water generated by power generation to supply hot water or heat are known.
Cogeneration systems include large ones used in power plants and factories and small ones used at home.
In Japan, small cogeneration systems for home use are becoming popular as an alternative to gas water heaters.
There are a system that uses a gas engine as a main heat source machine (Patent Document 1) and a system that uses a fuel cell as a main heat source machine (Patent Document 2) that have been put into practical use as a small cogeneration system for home use.

A cogeneration system using a gas engine drives a generator with a gas engine to generate electricity, raises the temperature of hot water using the heat generated by the gas engine, and uses the hot water for hot water supply. .
In a system using a fuel cell, hot water is heated using surplus heat of steam reforming, off-gas combustion heat, heat generation of the fuel cell itself, etc., and used for hot water supply.

  Here, in ordinary households, there is a difference between the time when power is required and the time when hot water supply is required, and in any cogeneration system, a structure in which hot water is stored in a storage tank is used to compensate for this difference. ing. That is, when there is a demand for electric power, power is generated by a gas engine or a fuel cell, hot water is made with the heat generated at this time, and the hot water is stored in a storage tank. And when there is demand for hot water supply, hot water is taken out from the storage tank and supplied for hot water supply.

Moreover, in the cogeneration system for home use, an auxiliary heat source machine is built in in preparation for the case where the required amount of hot water supply exceeds the amount of hot water stored in the storage tank.
The auxiliary heat source device is generally a gas burner, and generates more heat per unit time than a fuel cell as a main heat source device in order to meet an urgent and large amount of hot water supply demand.

  By the way, the heat demand in general households is not limited to hot water supply, but also requires heat energy for bathing and floor heating. For this reason, many gas water heaters have a function of supplying heat to a reheating bath or a floor heater.

  As described above, in Japan, small-sized cogeneration systems for home use are becoming popular as an alternative to gas water heaters. There is a market demand for adding a function of supplying heat to a heating appliance or the like.

In a system that uses a gas engine as a main heat source device in response to this requirement, as shown in FIG. 17, a heat exchanger 100 is provided in a flow path for sending a heat medium to a heating appliance, and on the primary side of the heat exchanger, This is dealt with by adopting a configuration in which the cooling water of the gas engine 101 is passed and heat is directly exchanged between the cooling water of the gas engine 101 and the heat medium of the heating appliance.
In the system shown in FIG. 17, there is a heat exchanger 105 that moves the heat of the gas engine 101 on the main body 102 side, a gas burner 106 that is an auxiliary heat source, and a heating appliance side in a flow path that passes through the heat exchanger 105. A heat exchanger 107 for moving heat and a heat exchanger 108 for bathing are provided. The heat exchangers 107 and 108 raise the temperature of the heater and reheat the bath.
Therefore, in the system using the gas engine 101, the gas burner 106 serving as an auxiliary heat source unit is only required to have only an auxiliary hot water supply function.

  On the other hand, when adding a function of supplying heat to a reheating bath or a floor heater to a system using a fuel cell as a main heat source unit, the gas burner 106 as an auxiliary heat source unit is merely an auxiliary unit. The hot water supply function alone is not sufficient, and the auxiliary heat source machine itself needs to have a function of replenishing a bath and a function of supplying heat to a floor heater.

That is, due to the characteristics of the fuel cell, the circuit of the cogeneration system using the gas engine 101 cannot be diverted to the cogeneration system using the fuel cell.
The reason for this is as follows.

  That is, the above-described gas engine has a wide range of adaptation of the temperature and flow rate of the cooling water. Therefore, there is no problem with the gas engine even if the amount of cooling water flowing on the gas engine 101 side is somewhat larger or smaller. Further, no problem occurs in the gas engine 101 even if the temperature of the cooling water flowing on the gas engine 101 side is somewhat high or low.

On the other hand, the fuel cell has a narrow adaptation range of the temperature and flow rate of the cooling water, and if the amount of the cooling water increases or decreases or the temperature of the cooling water changes, there is a possibility that the fuel cell may malfunction. This failure includes a failure of the exhaust heat recovery pump 25 in the power generation device 2 due to an increase in the cooling water temperature, and an increase in the flow rate of the cooling water, whereby the cooling water cannot be raised to a desired temperature by the fuel cell. , Etc. are included.
Therefore, the circuit configuration as shown in FIG. 17 cannot be adopted. That is, in a cogeneration system that employs a fuel cell as a main heat source machine, the load-side heat exchangers 107 and 108 cannot be connected in series to the heat exchanger 105 that takes heat away from the fuel cell.
That is, when the circuit configuration of FIG. 17 is adopted in the fuel cell, the temperature of the cooling water for cooling the fuel cell changes depending on whether the gas burner 106 is ignited or extinguished or whether heat exchange is performed in the heat exchangers 107 and 108.
In addition, as in the circuit configuration of FIG. 17, when the heat exchanger 100 is provided in the flow path for sending the heat medium to the heater, and the cooling water of the fuel cell is passed through the primary side of the heat exchanger. The flow resistance of the flow path for cooling the fuel cell changes depending on whether or not the heat medium flows through the heat exchanger 100, and the flow rate of the cooling water for cooling the fuel cell changes.

  Therefore, when adding a function for supplying heat to a bath reheating or floor heater to a system that uses a fuel cell, as shown in FIG. It is necessary to separately provide a gas burner 110 for supplying heat to a heating appliance or the like.

JP 2006-275386 A JP 2009-9880 A

  As described above, in the cogeneration system that uses the fuel cell of the prior art, in order to have the function of reheating the bath and supplying heat to the floor heater, etc., the auxiliary heat source machine itself has the function of retreating the bath. And a function of supplying heat to floor heaters and the like. Therefore, the cogeneration system using the fuel cell of the prior art has been dissatisfied with a large number of parts and a high manufacturing cost.

  Therefore, the present invention focuses on the problems of the prior art, and is a cogeneration system that uses a fuel cell, and has a function of supplying heat to a reheating bath or a floor heater in addition to hot water supply, and It is an object to develop a structure having a smaller number of parts than conventional ones.

  The invention according to claim 1 for solving the above-described problem is a main heat source device having a fuel cell and a heat exchanger for heat recovery for recovering heat generated by the fuel cell, and a unit more than the main heat source device. Auxiliary heat source unit with a large calorific value per hour, a storage tank that stores hot water in a state where temperature stratification is formed, a heat exchanger for supplying heat to external devices, and water supply from the outside The heat recovery heat exchanger has a water inlet for receiving water, a hot water outlet for discharging hot water to the outside, a pipe for connecting them, a valve and a pump, and opens and closes the valve. And a waste heat recovery circulation path that is connected in a ring including the storage tank, a heat utilization circulation path that is connected in a ring including the auxiliary heat source unit and the heat exchanger for heat supply, and a storage tank from the water inlet. And a hot water supply channel connected to the hot water outlet, and In a cogeneration system in which the flow paths are connected to each other directly or via other flow paths or members, water can be simultaneously passed through the exhaust heat recovery circulation flow path, the heat utilization circulation flow path, and the hot water supply flow path. In addition, when the water flows through the three flow paths at the same time, water flow between the exhaust heat recovery circulation flow path and the other flow paths is substantially blocked by opening / closing of the valve or pressure balance between the flow paths. Is a cogeneration system characterized by

Here, “a heat exchanger for supplying heat to an external device” refers to heat for supplying heat to a heating terminal such as a floor heater or a fan convector, or for retreating a bath. Refers to an exchange. The floor heater is a heating terminal that circulates a relatively low-temperature heat medium, and the fan convector is a heating terminal that circulates a relatively high-temperature heat medium.
The auxiliary heat source machine is preferably a burner using gas or oil as fuel, but may be an electric heater.
In the cogeneration system of the present invention, by opening and closing the valve, the heat recovery heat exchanger and the exhaust heat recovery circulation flow path including the storage tank and connected in an annular shape, an auxiliary heat source device, and a heat supply heat exchanger, It is possible to constitute a heat-utilizing circulation channel that is connected in an annular shape including a hot water supply channel that is connected from the water inlet to the hot water outlet through the storage tank.
Therefore, the heat generated by the fuel cell can be stored in the storage tank using the exhaust heat recovery circulation channel.
Moreover, heat required for a heating terminal etc. can be supplied using a heat utilization circulation channel. Furthermore, hot water can be supplied using a hot water supply channel.
Since the cogeneration system of the present invention can simultaneously pass through the exhaust heat recovery circulation channel, the heat utilization circulation channel and the hot water supply channel, hot water storage performed while starting the fuel cell and use of a heating terminal, etc. And hot water can be used at the same time.
In addition, when water is flowing through the three channels at the same time, water flow between the exhaust heat recovery circulation channel and the other channels is substantially blocked by opening / closing of the valve or pressure balance between the channels. Even when equipment is used or hot water is supplied, the amount and temperature of hot water flowing through the exhaust heat recovery circulation channel are not substantially changed as compared with the case where there is no hot water supply.
In addition, the auxiliary heat source apparatus employed in the present invention has only a function of heating hot water, and thus has a small number of parts.

  According to the second aspect of the present invention, the exhaust heat recovery circulation channel and the heat utilization circulation channel are connected by a plurality of short circuit paths, and are simultaneously passed through the exhaust heat recovery circulation channel, the heat utilization circulation channel, and the hot water supply channel. When water is supplied, the plurality of short-circuit paths are closed by a valve except for one short-circuit path, and the exhaust heat recovery circulation path and the heat-use circulation path are both in a state where water is not connected to the outside. The cogeneration system according to claim 1, wherein each valve is closed as follows.

  In the cogeneration system of the present invention, when water is simultaneously passed through the exhaust heat recovery circulation channel, the heat utilization circulation channel, and the hot water supply channel, the exhaust heat recovery circulation channel and the heat utilization circulation channel are both externally connected. Each valve is closed so that water flow is blocked. In the cogeneration system of the present invention, one of the short-circuit paths connecting the exhaust heat recovery circulation path and the heat utilization circulation path is open, but as described above, the exhaust heat recovery circulation path and the heat utilization circulation path are In any case, since the water flow to the outside is cut off, no substantial flow occurs in the short circuit due to the pressure balance. Therefore, even if a heating terminal is used or hot water is supplied, the amount and temperature of hot water flowing through the exhaust heat recovery circulation channel do not substantially change.

  According to a third aspect of the present invention, there is provided a heat recovery / heat utilization first short circuit that connects a part of the exhaust heat recovery circulation channel and a part of the heat utilization circulation channel, A heat recovery / heat utilization second short circuit connecting the part and another part of the heat utilization circulation channel, and the heat recovery / heat utilization first short circuit or the heat recovery / heat utilization second short circuit. The cogeneration system according to claim 2, further comprising a heat recovery / heat utilization opening / closing valve that intermittently passes water to and from.

Also in the cogeneration system of the present invention, when the exhaust heat recovery circulation channel, the heat utilization circulation channel and the water supply channel are simultaneously passed through, the exhaust heat recovery circulation channel and the heat utilization circulation channel are both externally connected. Each valve is closed so that the water flow is blocked. In the cogeneration system of the present invention, the heat recovery / heat utilization first short circuit and the heat recovery / heat utilization second short circuit exist between the exhaust heat recovery circulation channel and the heat utilization circulation channel. Since one of the two short-circuit paths is provided with a heat recovery / heat utilization opening / closing valve, the number of opened flow paths is limited to one by closing the opening / closing valve.
On the other hand, as described above, since both the exhaust heat recovery circulation channel and the heat utilization circulation channel are in a state where water flow from the outside is blocked, no substantial flow occurs in the short circuit described above. Therefore, even if a heating terminal is used or hot water is supplied, the amount and temperature of hot water flowing through the exhaust heat recovery circulation channel do not substantially change.

  The invention according to claim 4 includes a heat recovery pump that generates a water flow in the exhaust heat recovery circulation channel, and a heat circulation pump that generates a water flow in the heat utilization circulation channel. The first short circuit is between the discharge side of the exhaust heat recovery pump and the suction side of the heat circulation pump, and the second short circuit that uses heat recovery and heat is between the discharge side of the heat circulation pump and the suction side of the exhaust heat recovery pump. The cogeneration system according to claim 3, wherein the heat recovery / heat use opening / closing valve intermittently passes water through the heat recovery / heat use second short circuit.

  According to the present invention, when water is passed through the exhaust heat recovery circulation channel, the heat utilization circulation channel, and the hot water supply channel at the same time, there is no substantial flow in the short circuit, and the use of the heating terminal and the hot water supply can be performed. Even if it exists, the quantity and temperature of the hot water which flow through a waste heat recovery circulation channel do not change substantially.

  According to the fifth aspect of the present invention, the heat recovery / heat utilization first short circuit, a part of the heat utilization circulation flow path, and the flow path including the heat recovery / heat utilization second short circuit do not pass through the storage tank. The cogeneration system according to any one of claims 3 to 4, wherein a tank bypass circulation passage connecting the water inlet side and the water outlet side of the heat recovery heat exchanger is formed.

  In the present invention, a tank bypass circulation channel is formed by the heat recovery / heat utilization first short circuit, a part of the heat utilization circulation channel, and the heat recovery / heat utilization second short circuit. The tank bypass circulation passage is a passage through which hot water passes at the initial stage of activation of the cogeneration system, and is a passage provided for performing warm-up operation.

  In the invention according to claim 6, the heat recovery / heat utilization opening / closing valve is a three-way valve having three openings, and one of the openings of the three-way valve is connected to the heat recovery / heat utilization second short circuit, and the remaining two One opening is connected in the middle of the exhaust heat recovery circulation channel, and the three-way valve allows water to flow between the heat recovery / heat utilization second short circuit and one of the exhaust heat recovery circulation channels and the other flow. A state in which water is shut off, a state in which water is allowed to pass through the second short circuit of heat recovery / heat utilization and the other in the exhaust heat recovery circulation channel, and the other water is shut off, and heat recovery / heat 6. The cogeneration system according to claim 5, wherein the cogeneration system is capable of selecting a state in which water flow in the utilization second short-circuit path is blocked and water flow in the exhaust heat recovery circulation flow path is allowed.

  In the present invention, the flow path between the normal operation and the warm-up operation can be switched by operating the three-way valve.

  The invention according to claim 7 is a heat utilization / hot water short-circuit path connecting the downstream side of the auxiliary heat source unit and the hot water supply channel in the heat utilization circulation channel, and a communication path between the downstream side of the auxiliary heat source unit and the hot water supply channel. The water use / hot water supply opening / closing valve for intermittently supplying water is provided, and hot water heated by the auxiliary heat source device can flow through the hot water supply flow path. It is a cogeneration system.

In the cogeneration system of the present invention, the heat utilization / hot water short-circuit path connecting the downstream side of the auxiliary heat source unit and the hot water supply channel in the heat utilization circulation channel, and the water flow between the downstream side of the auxiliary heat source unit and the hot water channel. It has a heat utilization / hot water supply opening / closing valve that interrupts the operation. Therefore, the hot water heated by the auxiliary heat source device can be flowed to the hot water supply channel side by opening the heat utilization / hot water supply channel opening / closing valve.
Moreover, the heat utilization circulation channel and the hot water channel can be separated by closing the heat utilization / hot water channel opening / closing valve.

  The invention described in claim 8 includes a water inlet / heat recovery path short-circuit portion connecting the water inlet and the exhaust heat recovery circulation channel, and a water inlet / heat that intermittently passes the water through the water inlet and the exhaust heat recovery circulation channel. The cogeneration system according to any one of claims 2 to 7, further comprising a recovery path on-off valve.

  In the present invention, the water inlet and the exhaust heat recovery circulation channel are connected by the water inlet / heat recovery channel short-circuit portion. Further, an auxiliary heat source machine is connected to the exhaust heat recovery circulation channel. Therefore, water can be supplied to the auxiliary heat source device by operating the water inlet / heat recovery path opening / closing valve to open the water passage between the water inlet and the exhaust heat recovery circulation path.

  According to the ninth aspect of the present invention, the water inlet / heat recovery path opening / closing valve is a three-way valve, and allows water to flow between the water inlet and the exhaust heat recovery circulation flow path and allows water flow in the exhaust heat recovery circulation flow path. And a state in which water flow between the water inlet and the exhaust heat recovery circulation channel is blocked to allow water flow in the exhaust heat recovery circulation channel. 8. The cogeneration system according to 8.

  In the present invention, by switching the three-way valve, it is possible to switch between a circuit that heats incoming water from the water inlet with an auxiliary heat source device and a circuit that supplies heat to a heating device or the like.

  Although the cogeneration system of the present invention uses a fuel cell as a main heat source, it has a function of supplying heat to a reheating bath or a floor heating appliance in addition to hot water supply with fewer parts than conventional ones. There is an effect that can be given.

It is an operation principle figure of the cogeneration system of a first embodiment of the present invention. FIG. 2 is an operation principle diagram of the cogeneration system of FIG. 1, in which the exhaust heat recovery circulation passage is indicated by a thick line, and the flow of hot water in the exhaust heat recovery operation is indicated by an arrow. It is an operation | movement principle figure of the cogeneration system of FIG. 1, and shows the heat utilization circulation flow path by the thick line. It is an operation | movement principle figure of the cogeneration system of FIG. 1, and the hot water supply flow path is marked with the thick line, and the flow of the hot water in the hot water supply operation using the hot water of a storage tank is shown by the arrow. It is an operation | movement principle figure of the cogeneration system of FIG. 1, the tank bypass circulation flow path which detours a storage tank is marked with the thick line, and the flow of the hot water in the operation | movement initial stage of a cogeneration system is shown by the arrow. FIG. 2 is an operation principle diagram of the cogeneration system of FIG. 1, in which a heat utilization circulation passage and a heat medium passage are indicated by bold lines, and hot water flow and heat medium flow in heating operation are indicated by arrows. . FIG. 2 is an operation principle diagram of the cogeneration system of FIG. 1, in which a heat utilization circulation channel and a recirculation circulation channel are indicated by bold lines, and a hot water flow and a heat medium flow in a reheating operation are indicated by arrows. is there. FIG. 2 is an operation principle diagram of the cogeneration system of FIG. 1, in which a heat utilization circulation channel and a heating circulation channel are indicated by bold lines, and a hot water flow and a heat medium flow in a heating operation and a reheating operation are indicated by arrows. Is. FIG. 2 is an operation principle diagram of the cogeneration system of FIG. 1, and the flow of hot water when an exhaust heat recovery operation, a heating / reheating operation, and a hot water supply operation using hot water in a storage tank are simultaneously executed by arrows. It is shown. FIG. 2 is an operation principle diagram of the cogeneration system of FIG. 1, and shows the flow of hot water when hot water is taken out from a hot water storage tank and heated by a hot water supply device to indicate hot water. FIG. 2 is an operation principle diagram of the cogeneration system of FIG. 1, and shows the flow of hot water when the hot water is heated by a hot water supply device without using hot water in a hot water storage tank, and is indicated by a thick line and an arrow. is there. FIG. 2 is an operation principle diagram of the cogeneration system of FIG. 1, and shows the flow of hot water in the case of performing heating operation and reheating operation using hot water in a hot water storage tank by thick lines and arrows. FIG. 2 is an operation principle diagram of the cogeneration system of FIG. 1, and shows the flow of hot water when the temperature of the hot water in the hot water storage tank is raised by a hot water supply device by a thick line and an arrow. It is an operation principle figure of the cogeneration system of a second embodiment of the present invention. It is an operation principle figure of the cogeneration system of a third embodiment of the present invention. It is an operation | movement principle figure of the cogeneration system of 4th embodiment of this invention. It is an operation principle diagram of the cogeneration system disclosed in Patent Document 1. It is an operation principle diagram of the cogeneration system disclosed in Patent Document 2.

  Embodiments of the present invention will be further described below. In each figure, each valve with an arrow has a flow rate control function. In each figure, 1 is the cogeneration system of this embodiment. The cogeneration system 1 is roughly configured by combining a power generation device (main heat source machine) 2 and a heat recovery device 3.

  The power generation device 2 is composed of a fuel cell, and a heat generating unit 5 that generates heat accompanying power generation, and a heat exchanger for cooling the heat generating unit 5 and recovering exhaust heat generated during power generation ( Heat recovery heat exchanger) 6 and exhaust heat recovery pump 25. In other words, the power generation device 2 has a function as a power generation device for supplying power to a power load provided outside and a function as a thermal energy generation device for heating hot water (liquid). Yes.

The heat recovery device 3 includes a storage tank 10, a hot water supply device (auxiliary heat source device) 31, and two heat supply heat exchangers 38 and 42 as main components.
The two heat supply heat exchangers are specifically a heat exchanger for heat appliance 38 and a heat exchanger 42 for bathing.
The cogeneration system 1 includes an exhaust heat recovery circulation channel 7 (FIG. 2) and a heat utilization circulation channel 8 (FIG. 3) as main channels connecting the power generation device 2 and the devices in the heat recovery device 3. The hot water supply flow path 9 (FIG. 4) can be configured, and a plurality of short-circuit paths that connect these flow paths to each other are provided. Hereinafter, main devices constituting the heat recovery apparatus 3 will be described.

The storage tank 10 is a tank for storing hot water, and can form temperature stratification therein.
The storage tank is a closed tank, and top connection portions 11a and 11b provided at the top of the storage tank 10 and bottom connection portions 12a. It is set as the structure which connected the piping which comprises the exhaust heat recovery circulation flow path 7 and the hot water supply flow path 9 with respect to 12b. The top connection portions 11a and 11b and the bottom connection portions 12a. Although it is recommended that two 12b are provided as in the present embodiment, one 12b may be provided.

  The storage tank 10 has a configuration in which a plurality of (four in this embodiment) temperature sensors 13a to 13d are attached in the height direction, that is, in the direction in which the level of hot water stored in the storage tank 10 increases. The temperature sensors 13a to 13d function as temperature detection means for detecting the temperature of the hot water in the storage tank 10, respectively, and the remaining amount for detecting the remaining amount of hot water in the storage tank 10 at a predetermined temperature or temperature range. Also serves as a quantity detection means.

  In the cogeneration system 1 of the present embodiment, the low-temperature hot water taken out from the bottom of the storage tank 10 is discharged to the exhaust heat recovery circulation passage 7 and passes through the heat recovery heat exchanger 6 of the power generator 2. Heat exchange and heating are performed, and the storage tank 10 is slowly returned to the top side.

Here, in general, when a liquid is stored in a tank, if the temperature difference between the liquids is equal to or greater than a predetermined threshold (about 10 degrees Celsius for hot water), the liquid is divided into layers for each temperature. Therefore, the hot water passing through the exhaust heat recovery circulation channel 7 is heated to a temperature higher than the threshold temperature with respect to the temperature of the hot water in the storage tank 10 and slowly returned to the extent that the hot water in the storage tank 10 is not disturbed. If hot water is stored in the storage tank 10, it is divided into layers for each temperature. That is, temperature stratification is formed.
Therefore, it is possible to detect how much hot water heated to a desired temperature range is stored in the storage tank 10 by examining the detection temperatures of the temperature sensors 13 a to 13 d installed in the storage tank 10.

  The hot water supply device (auxiliary heat source machine) 31 includes a burner 41 and a heat exchanger 43 for burning fuel such as gas and kerosene as in a conventionally known hot water heater, and heat generated by the combustion of the fuel. The hot water is heated using energy. The hot water supply device 31 has a higher hot water heating capacity than the heat generating unit 5 of the power generation device 2. The hot water supply device 31 performs a combustion operation only in a special case such as when the temperature of the hot water discharged from the storage tank 10 is low, and heats the hot water flowing in the heat utilization circulation passage 8. Functions as a natural heat source. The hot water supply device 31 uses one of the operating conditions that the flowing water detection sensor 40 detects water flow exceeding a predetermined flow rate.

  One of the heat exchangers for heat supply 38 and is a heat exchanger for heat appliances. The heat exchanger for heat appliance 38 is connected to a heating circulation passage 70 described later on the secondary side, and heats the heat medium flowing through the heating circuit.

  The bath reheating heat exchanger 42 is connected to the recirculation circulation channel 71 on the secondary side, and raises the temperature of hot water in the bath (tub).

Next, main flow paths of the cogeneration system 1 will be described.
As described above, the cogeneration system 1 includes the exhaust heat recovery circulation passage 7 (FIG. 2), the heat utilization circulation passage 8 (FIG. 3), and the hot water supply passage 9 (FIG. 4) as main passages. Can be configured.
The exhaust heat recovery circulation channel 7 is a channel indicated by a thick line in FIG. 2, and the exhaust heat recovery pump 25 and the heat recovery heat exchanger 6 in the power generation device 2 and the storage tank 10 in the heat recovery device 3. Is a flow path that allows hot water to circulate between the storage tank 10 and the power generation device 2.
That is, the exhaust heat recovery circulation flow path 7 includes a heating forward flow path 21 that connects the bottom connection portion 12a of the storage tank 10 to the exhaust heat recovery pump 25 and the heat recovery heat exchanger 6 in the power generation device 2, and heat recovery. And a heating return side flow path 22 that connects the heat exchanger 6 for use and the top connection part 11a of the storage tank 10. A three-way valve 28 is interposed in the middle of the heating return side flow path 22.
The three-way valve 28 has an opening a, an opening b, and an opening c, and the flow path can be switched between two paths. That is, the three-way valve 28 can be switched between a state in which the opening a and the opening b communicate with each other and the other opening is closed, and a state in which the opening c and the opening a communicate with each other and the other opening is closed. .
In the present embodiment, the opening a and the opening b of the three-way valve 28 are connected to the exhaust heat recovery circulation channel 7.
A water supply short circuit 18 to be described later is connected to the other openings.

The heat utilization circulation channel 8 is a channel indicated by a thick line in FIG. 3, and includes a heat circulation pump 15, an auxiliary heat source device (hot water supply device 31), a heat supply heat exchanger (a heat exchanger heat exchanger 38). It is a flow path that includes the heat exchanger for bathing 42) and the three-way valve 26 and is connected in an annular shape in this order.
In the present embodiment, two heat supply heat exchangers (a heat exchanger for heat appliances 38 and a heat exchanger for reheating baths 42) are connected in parallel. On-off valves 23 and 24 are provided on the downstream side of the two heat supply heat exchangers, respectively. The on-off valves 23 and 24 are both electromagnetic valves.
Further, a three-way valve (heat recovery / heat utilization opening / closing valve) is provided between the downstream side of the heat supply heat exchangers 38, 42 (more precisely, downstream of the on-off valves 24, 23) and the upstream side of the heat circulation pump 15. ) 26 is provided.

The three-way valve 26 has an opening “a”, an opening “b”, and an opening “c”, and can further switch the flow path to three paths. That is, the three-way valve 26 has a state in which the opening a and the opening b communicate with each other and the other opening is closed, a state in which the opening b and the opening c communicate with each other, and a position between the other openings closes, and the opening c and the opening. It is possible to switch to a state in which a communicates with a and the other openings are closed.
In the present embodiment, the opening a of the three-way valve 26 is connected to the suction side of the heat circulation pump 15, and the opening b is connected to the downstream side of the heat supply heat exchangers 38 and 42.

The hot water supply channel 9 is a channel indicated by a thick line in FIG. 4 and is a channel that enters the water inlet 33 from an external water supply source and is connected to the hot water outlet 44 via the storage tank 10.
The hot water supply flow path 9 is a flow path that enters the lower part of the storage tank 10 from the water inlet 33 through the water supply flow path 50, and reaches the hot water outlet 44 through the hot water passage 52 from the top connection portion 11 b of the storage tank 10.
If it demonstrates one by one, the water supply flow path 50 is a flow path for supplying hot water from an external water supply source, and the terminal part is connected to the bottom part connection part 12b provided in the bottom part side of the storage tank 10. FIG. Thereby, the cogeneration system 1 is configured to be able to introduce low-temperature hot water supplied from the outside from the bottom side of the storage tank 10.

In the water supply channel 50, a hot water supply channel 50b is branched in the middle.
The hot water supply water flow path 50 b is a flow path for joining hot water supplied from the outside with hot water flowing through the hot water passage 52. A check valve 57 for preventing hot water from flowing back from the hot water passage 52 side toward the water inlet 33 side is provided in the middle of the hot water supply water flow path 50b.

  The hot water supply channel 50 b is configured to be branched into a main flow portion 53 and a branch flow portion 55 at a branch portion 54 on the downstream side of the check valve 57. The main flow portion 53 is connected to the hot water passage 52 via the hot water / water mixing valve 32. Then, the amount of hot water joining the hot water passage 52 is adjusted by adjusting the opening degree of the hot water mixing valve 32, and the temperature of the hot water discharged from the hot water outlet 44 is adjusted. In the present embodiment, the open / close valve 39 is provided in the hot water passage 52.

  The tributary part 55 has an electromagnetic valve 58 at a position downstream of the branch part 54. The electromagnetic valve 58 is a valve that is opened when the power is not supplied. When the hot water mixing valve 32 cannot be opened due to a power failure, the hot water in the storage tank 10 is discharged as it is, and so-called high temperature hot water is discharged. It is provided to prevent it from happening.

Next, a short circuit connecting the three main channels (exhaust heat recovery circulation channel 7, heat utilization circulation channel 8, and hot water supply channel 9) will be described.
The exhaust heat recovery circulation path 7 and the heat utilization circulation path 8 are connected by two short-circuit paths. One is a heat recovery / heat utilization first short circuit 35, which is a part of the heating return side flow path 22 of the exhaust heat recovery circulation flow path 7, and is branched between the power generator 2 and the three-way valve 28. The heat circulation path 8 is connected to the upstream side of the heat circulation pump 15.
It can be said that the heat recovery / heat utilization first short circuit 35 is located between the discharge side of the exhaust heat recovery pump 25 and the suction side of the heat circulation pump 15.

Another short circuit is the heat recovery / heat utilization second short circuit 17, which connects the opening c of the three-way valve 26 and the heating-side flow path 21 of the exhaust heat recovery circulation path 7.
More specifically, the heat utilization circulation passage 8 includes the discharge side of the heat circulation pump 15, the hot water supply device 31, the heat exchangers 38 and 42, the opening b of the three-way valve 26, the opening a of the three-way valve 26, heat The exhaust heat recovery circulation flow path 7 is a flow path that connects the suction side of the circulation pump 15 in this order. The exhaust heat recovery circulation path 7 is a discharge side of the exhaust heat recovery pump 25, a heat recovery heat exchanger 6, an opening a of the three-way valve 28, a three-way valve. 28 is a flow path connecting the opening b of the storage tank 10, the top connection portion 11 a of the storage tank 10, the bottom connection portion 12 a of the storage tank 10, and the suction side of the exhaust heat recovery pump 25 in this order. One base end of the heat recovery / heat utilization second short circuit 17 is at the opening c of the three-way valve 26, and the other base end is on the bottom connection portion 12 a of the storage tank 10 and the suction side of the exhaust heat recovery pump 25. between.
It can be said that the heat recovery / heat utilization second short circuit 17 is between the discharge side of the heat circulation pump 15 and the suction side of the exhaust heat recovery pump 25.

In this embodiment, the heat recovery / heat utilization first short circuit 35, the heat utilization circulation channel 8 part 16, and the heat recovery / heat utilization second short circuit 17 partially form the tank bypass circulation channel 20. Is formed.
That is, the three-way valve 26 provided in the exhaust heat recovery circulation flow path 7 is rotated to connect the opening a and the opening c, the heat recovery / heat utilization second short circuit 17 is opened, and the exhaust heat recovery circulation flow path 7 By connecting the upstream region of the exhaust heat recovery pump 25 and the heating return side flow path 22, the tank-by-bass circulation flow path 20 (FIG. 5) can be configured, and hot water discharged from the power generator 2 is stored. A tank-by-bass circulation channel 20 that bypasses the tank 10 and returns to the power generation device 2 can be formed.

The exhaust heat recovery circulation channel 7 and the hot water supply channel 9 are connected by a water supply short circuit 18. The water supply short-circuit path 18 is connected to a part of the water supply path 50 and the opening c of the three-way valve 28 of the exhaust heat recovery circulation path 7. A check valve 37 is provided in the middle of the water supply short circuit 18.
Further, as described above, since the exhaust heat recovery circulation channel 7 is connected to the heat utilization circulation channel 8 via the heat recovery / heat utilization first short circuit 35, the hot water supply channel 9 includes the water supply short circuit 18 and It is also connected to the heat utilization circulation channel 8 via a part of the exhaust heat recovery circulation channel 7.
As described above, since the water supply channel 50 is a channel for supplying hot water from an external water supply source, the cold water supplied from outside is part of the water supply short circuit 18 and the exhaust heat recovery circulation channel 7. The cold water supplied from the outside can be heated by the hot water supply device 31 provided in the heat use circulation channel 8.

Further, the heat utilization circulation channel 8 and the hot water supply channel 9 are connected by a high temperature hot water short circuit 19.
Therefore, the hot water heated by the hot water supply device 31 can be introduced into the hot water supply passage 9.
That is, in the present embodiment, the high temperature hot water short circuit 19 is provided on the downstream side of the hot water supply device 31 in the heat utilization circulation channel 8, and the end of the high temperature hot water short circuit 19 is connected to the hot water passage 52. An open / close valve 34 is provided in the high temperature hot water short circuit 19.

Next, the flow path connected to the secondary side of the heat exchanger for heat supply (heat exchanger 38 for heat appliance and heat exchanger 42 for bathing) will be briefly described.
As described above, the flow path for supplying the heat medium to the heating appliances 63a and 63b is connected to the secondary side of the heat exchanger for heat appliance 38.
The flow path for supplying the heat medium includes a high-temperature heat medium forward flow path 60 for supplying a high-temperature heat medium to a fan convector, a low-temperature heat medium forward flow path 61 for supplying a low-temperature heat medium to a floor heating appliance, and the like. A heat medium return channel 62 is provided for returning the heat medium from both.

  The heat medium returned from the heat medium return flow path 62 enters the heating pump 65 through the expansion tank 64, is pressurized by the heating pump 65, is introduced to the entry side of the heat exchanger for heat appliance 38, and is heated. The temperature is raised by the appliance heat exchanger 38 and sent to the high-temperature heat medium forward flow path 60.

On the other hand, the discharge side of the heating pump 65 is branched and connected to the low-temperature heat medium forward flow path 61, and a part of the heat medium flowing through the heat medium return flow path 62 is not heated and the floor heating appliance is heated. 63a and the like.
A bypass flow path 72 is provided between the high temperature heat medium forward flow path 60 and the low temperature heat medium forward flow path 61, and a check valve 73 is interposed in the bypass flow path 72.
A bypass flow path 74 is also provided between the low temperature heat medium forward flow path 61 and the heat medium return flow path 62.

A recirculation circulation channel 71 is connected to the secondary side of the heat exchanger 42 for reheating the bath. A bath pump 69 is provided in the recirculation circulation channel 71.
Further, a drop channel 67 is provided between the recirculation circulation channel 71 and the hot water supply channel 9. An opening / closing valve 68 is provided in the dropping channel 67.

  The operation of the cogeneration system 1 of this embodiment is controlled by the control means 80. The control means 80 is the same as that provided in a conventionally known cogeneration system, and can be configured to include, for example, a CPU and a memory in which a predetermined control program is built. The control unit 80 operates the valves, the power generation device 2, the hot water supply device 31 and the like provided in each part of the cogeneration system 1 based on the detection signals of the sensors provided in each part, the data stored in the memory, and the like. Is controlled to optimize the total energy efficiency of the cogeneration system 1.

  Then, operation | movement of the cogeneration system 1 of this embodiment is demonstrated in detail, referring drawings. The cogeneration system 1 can operate by selecting an operation mode from an operation mode group including a storage mode, a hot water supply mode, a heating mode, and a detour mode. The cogeneration system 1 can perform the storage mode, the hot water supply mode, and the heating mode independently or in combination. Hereinafter, the operation of the cogeneration system 1 will be described for each operation mode.

(Storage mode)
In the storage mode, the exhaust heat recovery pump 25 is operated to generate a water flow in the exhaust heat recovery circulation channel 7 as shown by a thick line or an arrow in FIG. This is an operation mode in which heat (heat energy) is recovered to heat the hot water and the hot water is stored in the storage tank 10. The storage mode is an operation mode that is performed on condition that the temperature of the hot water flowing through the heating return side flow path 22 toward the storage tank 10 is equal to or higher than a predetermined temperature.

When the cogeneration system 1 operates in the storage mode, based on the control signal transmitted from the control means 80, the three-way valve 28 is closed with respect to the feed water short circuit 18, and the heating return side channel 22 is connected to the top of the storage tank 10. It adjusts to the state opened with respect to the part 11a.
The other three-way valve 26 is in a state where the opening a and the opening b communicate with each other and the other openings are closed. That is, the heat utilization circulation flow path 8 is opened and the heat recovery / heat utilization second short-circuit path 17 is closed.

Further, when the storage mode is operated alone, the heat circulation pump 15 of the heat utilization circulation channel 8 is stopped.
The on-off valve 34 provided in the high temperature hot water short circuit 19 is closed.

  When the exhaust heat recovery pump 25 is operated with the three-way valves 28 and 26 and the opening / closing valve 34 adjusted as described above, a hot water circulating flow as shown by arrows in FIG. 2 is generated. More specifically, when the cogeneration system 1 operates in the storage mode, the low-temperature hot water stored on the bottom side of the storage tank 10 with the operation of the exhaust heat recovery pump 25 is discharged from the bottom connection portion 12a. Sucked into the heating-out side flow path 21 and supplied to the power generation device 2. Thereby, hot water sucked out from the storage tank 10 is supplied to the heat recovery heat exchanger 6 in the power generation device 2, the power generation device 2 is cooled, and thermal energy generated in association with the operation of the power generation device 2. Is absorbed in the hot water supplied to the heat recovery heat exchanger 6. The hot water heated and exchanged in the heat recovery heat exchanger 6 is returned to the storage tank 10 from the top connection portion 11a via the heating return side flow path 22. Thereby, the hot water in the storage tank 10 is heated gradually.

In this embodiment, as shown in FIG. 2, the exhaust heat recovery circulation channel 7 is connected to the heat utilization circulation channel 8 by the heat recovery / heat utilization first short circuit 35, but the pressure balance is functioning. The hot water in the exhaust heat recovery circulation channel 7 does not flow into the heat utilization circulation channel 8. In other words, no water flow occurs in the heat recovery / heat utilization first short circuit 35.
That is, as described above, when the cogeneration system 1 operates in the storage mode, the three-way valve 28 is closed with respect to the feed water short circuit 18 based on the control signal transmitted from the control means 80. The on-off valve 34 provided in the high temperature hot water short circuit 19 is also closed. Therefore, the heat use circulation channel 8 has no hot water inlet / outlet except for the heat recovery / heat use first short circuit 35, and a water flow is generated in the exhaust heat recovery circuit 7 so that the heat recovery / heat use first short circuit is provided. Even if the exhaust heat recovery circulation passage 7 of 35 is in a high pressure state, the heat utilization circulation passage 8 which is a closed space has the same pressure as the exhaust heat recovery circulation passage 7 and does not allow inflow of hot water.
Therefore, in this embodiment, there is no on-off valve in the heat recovery / heat utilization first short circuit 35, but water does not flow through the heat recovery / heat utilization first short circuit 35. The present invention does not exclude the provision of an on-off valve in the heat recovery / heat utilization first short circuit 35.

  As described above, the storage mode is an operation mode that is performed on the condition that the temperature of the hot water flowing through the heating return side passage 22 toward the storage tank 10 side is equal to or higher than a predetermined temperature. When the temperature of the hot water flowing through the passage 22 is low, hot water is passed through the tank bypass circulation passage 20 in order to prevent the temperature stratification in the storage tank 10 from being broken.

That is, in the initial operation of the cogeneration system 1, since the temperature of the hot water sent from the power generation device 2 to the heat recovery device 3 is low and unsuitable for storage, a water flow is generated as shown by a thick line or an arrow in FIG. Then, the hot water heated by the power generation device 2 is returned to the power generation device 2 side through the heating forward flow path 21 as it is.
More specifically, the three-way valve 26 provided in the heat utilization circulation channel 8 is in a state in which the opening a and the opening c communicate with each other and the other openings are closed. In other words, the heat recovery / heat utilization second short-circuit path 17 is opened to prevent communication between the heat utilization circulation paths 8.
Further, the three-way valve 28 is adjusted so that the space between the feed water short-circuit path 18 and the heating return side flow path 22 is open and closed with respect to the top connection portion 11 a of the storage tank 10.

As a result, the heating return side flow path 22 from the power generator 2, the heat recovery / heat utilization first short circuit 35, a part 16 of the heat utilization circulation path 8, the three-way valve 26, the heat recovery / heat utilization second short circuit 17. Then, a series of flow paths returning to the power generation device 2 through the heating forward flow path 21 is opened.
Looking at the heat utilization circulation channel 8, the three-way valve 26 prevents communication between the heat utilization circulation channels 8. Therefore, if no hot water is supplied and the on-off valve 34 is closed, heat utilization is performed. The circulation channel 8 is a closed space, and hot water is not mixed into other parts of the heat utilization circulation channel 8.
The flow path that enters the three-way valve 28 from the heating return side flow path 22 of the exhaust heat recovery circulation flow path 7 and flows back through the feed water short-circuit path 18 is blocked by the check valve 37 and is closed. There is no water flow on the road.

(Water supply mode using only hot water in the tank)
The hot water supply mode using only hot water in the tank is an operation mode in which hot water is supplied using high-temperature hot water stored in the storage tank 10 in the above-described storage mode. When the cogeneration system 1 operates in the hot water supply mode, a water flow is generated in the hot water supply passage 9 as shown by a thick line or an arrow in FIG.

More specifically, when the cogeneration system 1 operates in the hot water supply mode using only the hot water in the tank, the control means 80 closes the on-off valve 34 provided in the high temperature hot water short circuit 19 and the heat utilization circulation channel 8. And the water flow between the water supply flow paths 50 are blocked. The solenoid valve 58 is closed.
As a result, a low-temperature hot water supplied from an external water supply source can be joined to the hot water supply passage 9 by a predetermined amount via the main flow portion 53 of the hot water supply water supply passage 50b.

  In this state, when low temperature hot water is introduced from the outside through the water inlet 33 by opening an unillustrated curan or the like, one of the low temperature hot water supplied from an external water supply source is shown in FIG. The part flows into the storage tank 10 from the bottom connection part 12b through the water supply channel 50. Thereby, hot hot water stored on the top side of the storage tank 10 is discharged through the top connection portion 11 b and flows into the hot water supply passage 9. That is, when hot water is introduced from the water inlet 33 to the bottom of the storage tank 10, hot hot water accumulated on the top side of the storage tank 10 is pushed up to the top side and pushed out to the hot water passage 52.

On the other hand, the remaining portion of the low-temperature hot water supplied from the external water supply source flows into the hot water supply water supply channel 50 b and is introduced into the hot water supply channel 9 through the main flow part 53. The hot water is discharged from the top connection portion 11 b of the storage tank 10, merged with the hot water flowing through the hot water passage 52 and the hot water mixing valve 32, and mixed so as to become hot water having a desired temperature.
The hot water having a predetermined temperature is discharged from the hot water outlet 44.

(Heating mode)
In the heating mode, the hot water supply device 31 is combusted to raise the temperature of the hot water in the heat-use circulation channel 8, and the hot water in the heat-use circulation channel 8 is heat-exchanged and heated in the heat exchanger for heat appliance 38. This is an operation mode supplied to the heating terminals 63a and 63b. When the heating mode is selected, a circulating flow of hot water or a heat medium is generated as shown by a thick line or an arrow in FIG.

More specifically, when the cogeneration system 1 operates in the heating mode, the control means 80 communicates the three-way valve 26 provided in the heat utilization circulation passage 8 with the opening a and the opening b communicating with each other. The space between the openings is closed. That is, the heat utilization circulation flow path 8 is opened and the heat recovery / heat utilization second short-circuit path 17 is closed.
The other three-way valve 28 may be in any posture.
In the heating mode, the on-off valve 23 provided on the downstream side of the heat exchanger for heat appliance 38 is opened, the on-off valve 24 provided on the downstream side of the heat exchanger for reheating a bath 42 is closed, and a high-temperature hot-water short circuit occurs. The on-off valve 34 of the passage 19 is also closed.
When the heat circulation pump 15 is started in a state where the opening degree is adjusted in this way, as shown by a thick line or an arrow in FIG. 6, a heat utilization circulation channel that passes through the hot water supply device 31 and the heat exchanger for heat appliance 38. A water flow is generated at 8. And the hot water supply apparatus 31 is ignited and the temperature of the hot water flowing through the heat utilization circulation passage 8 is raised.
As a result, hot water flows on the primary side of the heat exchanger for heat appliance 38, and the temperature of the heat medium flowing on the secondary side is increased.

As described above, regardless of the posture of the three-way valve 28, hot water does not flow out of the heat utilization circulation channel 8 regardless of the posture of the three-way valve 28.
That is, the flow from the heat utilization circulation passage 8 through the heat recovery / heat utilization first short circuit 35 to the exhaust heat collection circulation passage 7 is the exhaust heat collection circulation passage 7 is a closed space, and the hot water enters and exits. It does not occur because there is no.
The flow path that enters the three-way valve 28 from the heat utilization circulation flow path 8 through the heat recovery / heat utilization first short circuit path 35 and further flows back through the water supply short circuit path 18 is blocked by the check valve 37 and closed.

  On the other hand, the control means 80 activates the heating pump 65 provided in the heating-side circulation flow path 70 that supplies the heat medium to the heating appliances 63 a and 63 b, and the circulation flow of the heat medium in the heating-side circulation flow path 70. Is generated. As a result, the heat energy of the hot water circulating in the heat utilization circulation channel 8 is released in the heat exchanger for heat appliance 38, and the hot water and the heat medium circulating in the heating-side circulation channel 70 are heat exchange heated. The hot water and the heat medium heat exchanged and heated in the heat exchanger for heat appliance 38 are supplied to the heating terminals 63a and 63b and used as a heat source for heating.

(Chance mode)
The operation in the reheating mode is substantially the same as the heating mode described above. However, in the reheating mode, the on-off valve 24 provided on the downstream side of the heat exchanger 42 for reheating the bath is opened to The on-off valve 23 provided on the downstream side of the heat exchanger 38 is closed. When the heat circulation pump 15 is started in a state where the opening degree is adjusted in this way, water flows in the heat utilization circulation passage 8 passing through the reheating heat exchanger 42 as shown by a thick line or an arrow in FIG. Arise.

  Also, the bath pump 69 provided in the recirculation circulation passage 71 is activated to generate a circulation flow of the heat medium in the recirculation circulation passage 71. As a result, the heat energy of the hot water circulating in the heat utilization circulation channel 8 is released in the reheating heat exchanger 42, and the hot water and heat medium circulating in the recirculation circulation channel 71 are heat-exchanged and heated. The hot water is heated.

  The heating mode and the reheating mode described above may be executed simultaneously. The flow of hot water when the heating mode and the reheating mode are executed simultaneously is as shown in FIG.

(Storage / hot water / heating mode)
In the cogeneration system 1 of this embodiment, the main modes described above can be performed simultaneously. That is, the waste heat (thermal energy) generated with the operation of the power generator 2 is recovered to heat the hot water and the hot water is stored in the storage tank 10, and the hot water supply mode in which hot water is supplied only by the hot water in the tank. The heating reheating mode can be executed at the same time.
That is, FIG. 2 showing the flow of hot water in the storage mode, FIG. 4 showing the flow of hot water in the hot water supply mode, and FIG. 3 showing the flow of hot water in the heating and reheating mode are overlapped and compared. There is no overlapping part of the route. Therefore, water can be simultaneously passed through the exhaust heat recovery circulation passage 7, the heat utilization circulation passage 8 and the hot water supply passage 9, and when the water is simultaneously passed through the three passages, the valve is opened or closed or between the passages. Water flow between the three flow paths is substantially blocked by the pressure balance.

More specifically, when the main mode is performed simultaneously, based on the control signal transmitted from the control means 80, the three-way valve 28 is closed with respect to the feed water short circuit 18 and the heating return side flow path 22 is the storage tank. It adjusts to the state opened with respect to 10 top connection parts 11a.
The other three-way valve 26 is in a state where the opening a and the opening b communicate with each other and the other openings are closed. That is, the heat utilization circulation channel 8 is opened and the feed water short circuit 18 is closed.
The on-off valve 34 provided in the high temperature hot water short circuit 19 is closed.

The exhaust heat recovery pump 25 and the heat circulation pump 15 are operated with the three-way valves 28 and 26 and the opening / closing valve 34 adjusted as described above. When low-temperature hot water is introduced from the outside through 33, as shown by arrows in FIG. 9, a hot water flow path is provided in each of the exhaust heat recovery circulation path 7, the heat utilization circulation path 8, and the hot water supply path 9. Will occur.
And hot water flowing through each flow path is not mixed.
That is, as described above, the exhaust heat recovery circulation channel 7, the heat utilization circulation channel 8, and the hot water supply channel 9 are composed of the heat recovery / heat utilization first short circuit 35 and the heat recovery / heat utilization second short circuit 17. And a water supply short circuit 18 and a high temperature hot water short circuit 19.
More specifically, the heat recovery / heat utilization first short circuit 35 and the heat recovery / heat utilization second short circuit 17 are connected between the exhaust heat recovery circulation path 7 and the heat utilization circulation path 8. ing.
The exhaust heat recovery circulation channel 7 and the hot water supply channel 9 are connected by a water supply short circuit 18.
The heat utilization circulation channel 8 and the hot water supply channel 9 are connected by a high temperature hot water short circuit 19.

An open / close valve 34 is provided in the high temperature hot water short circuit 19. When the main mode is performed simultaneously, the on-off valve 34 is closed, the high temperature hot water short circuit 19 is closed, and the space between the heat utilization circulation channel 8 and the hot water supply channel 9 is closed.
Moreover, although the opening c of the three-way valve 28 exists in the edge part of the water supply short circuit 18, when performing main mode simultaneously, the opening c of the three-way valve 28 mentioned above is closed, and the water supply short circuit 18 is closed. The space between the exhaust heat recovery circulation channel 7 and the hot water supply channel 9 is also closed.

  The heat recovery / heat utilization second short circuit 17 provided between the exhaust heat recovery circulation path 7 and the heat utilization circulation path 8 is connected to the opening c of the three-way valve 26. When performing, the opening c of the three-way valve 26 is closed, the heat recovery / heat utilization second short circuit 17 is closed, and one of the exhaust heat recovery circulation path 7 and the heat utilization circulation path 8 is short-circuited. Is closed.

There is no on-off valve in the heat recovery / heat utilization first short circuit 35, but the heat recovery / heat utilization first short circuit 35 is provided with the heat recovery / heat utilization second short circuit 17 when the main mode is performed simultaneously. Since it is closed, it is the only open communication path connecting the exhaust heat recovery circulation channel 7 and the heat utilization circulation channel 8, and the exhaust heat recovery circulation channel 7 is also the heat utilization circulation channel 8. However, since it is a closed space and there is no outlet for hot water outside the flow path, there is no circulation of hot water due to the pressure balance in the heat recovery / heat utilization first short circuit 35. Therefore, as described above, the hot water flowing through each flow path is not mixed, and the flow rate change of the other flow path and the temperature change of the hot water are not caused by the presence or absence of the flow of the other flow path.
Therefore, the amount and temperature of the hot water flowing through the exhaust heat recovery circulation passage 7 do not change depending on whether or not another operation mode is executed during the storage mode, and the fuel cell is operated smoothly. It will not be out of range.

The cogeneration system 1 of the present embodiment can be operated in 60 or more operation modes in addition to the operation modes described above.
Among them, a relatively important operation mode will be described.

(Hot-water supply mode with hot water storage device and hot water storage tank)
The hot water supply apparatus / hot water storage tank combined hot water supply mode is an operation mode in which high-temperature hot water is pushed out from the upper part of the storage tank 10 and the hot water is heated by the hot water supply apparatus to be used for hot water supply.
The hot water supply apparatus / hot water tank combined hot water supply mode is an operation mode that is executed when the temperature of the hot water in the storage tank 10 is low.

When the cogeneration system 1 operates in the hot water supply mode using the hot water supply apparatus and hot water storage tank, a water flow is generated in a part of the heat utilization circulation channel 8 and a part of the hot water supply channel 9 as shown by thick lines and arrows in FIG. .
That is, when the cogeneration system 1 operates in the hot water supply apparatus / hot water storage tank combined hot water supply mode, the three-way valve 28 is closed with respect to the short water supply path 18 based on the control signal transmitted from the control means 80, and the heating return side flow path 22. Is adjusted to be open with respect to the top connection part 11a of the storage tank 10.
The other three-way valve 26 may be in any posture.
The on-off valve 34 provided in the high-temperature hot water short-circuit 19 opens to allow water flow between the heat utilization circulation passage 8 and the water supply passage 50. The solenoid valve 58 is closed.
Further, the on-off valve 23 provided on the downstream side of the heat exchanger for heat appliance 38 and the on-off valve 24 provided on the downstream side of the heat exchanger 42 for reheating the bath are both closed.

When operating in the hot water supply apparatus / hot water storage tank combined hot water supply mode, the exhaust heat recovery pump 25 in the power generator 2 stops. The heat circulation pump 15 of the heat utilization circulation channel 8 is operated.
In this state, when low temperature hot water is introduced from the outside through the water inlet 33 by opening a curan (not shown) or the like, one of the low temperature hot water supplied from an external water supply source is shown in FIG. The part flows into the storage tank 10 from the bottom connection part 12b through the water supply channel 50. Thereby, the hot hot water stored by the top side of the storage tank 10 is extruded from the top connection part 11a. Here, in this embodiment, since the heat circulation pump 15 of the heat utilization circulation channel 8 is operating, the hot water from the storage tank 10 is pushed out from the top connection portion 11a side, and the opening b and the opening of the three-way valve 28 are opened. A part of the heating return side flow path 22 flows backward via a, and further enters the heat utilization circulation flow path 8 via the heat recovery / heat utilization first short circuit 35.
Then, hot water is heated in the heat utilization circulation channel 8 by the hot water supply device 31 and flows into the downstream side of the hot water supply channel 9 through the high temperature hot water short circuit 19. That is, when hot water is introduced from the water inlet 33 to the bottom of the storage tank 10, hot hot water accumulated on the top side of the storage tank 10 is pushed up to the top side and flows into the heat utilization circulation channel 8. It is heated by the device 31. Since the on-off valve 34 provided in the high-temperature hot water short-circuit 19 is open, the hot water heated in the heat utilization circulation passage 8 flows into the upstream side of the hot water mixing valve 32 and downstream of the hot water supply passage 9. enter.

  On the other hand, the remaining portion of the low-temperature hot water supplied from the external water supply source flows into the hot water supply water supply channel 50 b and is introduced into the hot water supply channel 9 through the main flow part 53. The hot water and hot water heated in the heat utilization circulation passage 8 are merged by the hot water mixing valve 32, mixed to become hot water at a desired temperature, and discharged from the hot water outlet 44.

(Hot water supply unit single hot water supply mode)
The hot water supply unit hot water supply mode is an operation mode in which the hot water in the storage tank 10 is not used at all, and the incoming water is heated by the hot water supply device and used for hot water supply.

When the cogeneration system 1 operates in the hot water supply apparatus single hot water supply mode, a water flow is generated in a part of the heat utilization circulation channel 8 and a part of the hot water supply channel 9 as shown by a thick line or an arrow in FIG.
That is, when the cogeneration system 1 operates in the hot water supply device single hot water supply mode, the three-way valve 28 is adjusted so as to communicate with the opening a and the opening c. That is, the water supply short-circuit path 18 and the heating return side flow path 22 are communicated, and the flow path reaching the top connection portion 11a of the storage tank 10 is closed.
Further, the other three-way valve 26 is adjusted to a posture in which the heat utilization circulation passage 8 is closed.
The on-off valve 34 provided in the high-temperature hot water short-circuit 19 opens to allow water flow between the heat utilization circulation passage 8 and the water supply passage 50. The solenoid valve 58 is closed.
The on-off valve 23 provided on the downstream side of the heat exchanger for heat appliance 38 and the on-off valve 24 provided on the downstream side of the heat exchanger for reheating a bath are both closed.

When operating in the hot water supply unit hot water supply mode, the exhaust heat recovery pump 25 in the power generator 2 is stopped. The operation of the heat circulation pump 15 in the heat utilization circulation channel 8 is also stopped.
In this state, when low temperature hot water is introduced from the outside through the water inlet 33 by opening a curan (not shown) or the like, one of the low temperature hot water supplied from an external water supply source is shown in FIG. Part enters the water supply short-circuit path 18 from the water supply flow path 50, flows back through a part of the heating return side flow path 22 via the openings c and a of the three-way valve 28, and further heat recovery / heat utilization first short circuit The heat-use circulation flow path 8 is entered via the path 35.
Then, it flows into the hot water supply passage 9 via the thermal circulation pump 15. That is, when cold water is introduced from the water inlet 33, the cold water flows into the heat utilization circulation channel 8 without passing through the storage tank 10, and the cold water is heated by the hot water supply device 31. And since the on-off valve 34 provided in the high temperature hot water short circuit 19 is open, the hot water heated in the heat utilization circulation channel 8 flows into the hot water supply channel 9.

  On the other hand, the remaining portion of the low-temperature hot water supplied from the external water supply source flows into the hot water supply water supply channel 50 b and is introduced into the hot water supply channel 9 through the main flow part 53. The hot water and hot water heated in the heat utilization circulation passage 8 are merged by the hot water mixing valve 32, mixed to become hot water at a desired temperature, and discharged from the hot water outlet 44.

(Heating and reheating mode using hot water tank heat)
The heating / reheating mode using hot water storage tank heat is an operation mode in which hot water is pushed out from the upper part of the storage tank 10 and heating or reheating is performed using this hot water.

When the cogeneration system 1 operates in the heating / reheating mode using hot water storage tank heat, a water flow is generated in the heat utilization circulation passage 8 as shown by a thick line or an arrow in FIG.
That is, when the cogeneration system 1 operates in the heating / reheating mode using hot water storage tank heat, the three-way valve 28 is in a state where the opening b and the opening a communicate with each other. That is, the three-way valve 28 is adjusted so that it closes with respect to the feed water short-circuit path 18 and opens the upstream heating flow path 21 a with respect to the top connection portion 11 a of the storage tank 10.
The other three-way valve 26 is in a state where the opening c and the opening b communicate with each other.
That is, the downstream side of the heat exchanger for heat appliances 38 and the downstream side of the heat exchanger for reheating a bath 42 are in communication with the heat recovery / heat utilization second short circuit 17.

The on-off valve 23 provided on the downstream side of the heat exchanger for heat appliance 38 and the on-off valve 24 provided on the downstream side of the heat exchanger 42 for reheating the bath are both opened.
The on-off valve 34 provided in the high temperature hot water short circuit 19 is closed.

Further, when operating in the heating / heating mode using hot water storage tank heat, the exhaust heat recovery pump 25 in the power generator 2 is stopped. The heat circulation pump 15 of the heat utilization circulation channel 8 is operated. The hot water supply device 31 does not burn.
As a result, the heat circulation pump 15, the hot water supply device 31, the heat exchanger 38 for heat appliances and the heat exchanger 42 for reheating the bath, the opening / closing valves 23 and 24, the openings b and c of the three-way valve 26, the heat recovery / heat Use second short circuit 17, bottom connection part 12 a of storage tank 10, top connection part 11 a of storage tank 10, opening b and opening a of three-way valve 28, heating return side flow path 22, heat recovery / heat use first short circuit A series of annular flow paths leading to the passage 35 and the heat circulation pump 15 are opened, and a water flow is generated in the annular flow path.

  Therefore, hot hot water stored on the top side of the storage tank 10 is pushed out from the top connection part 11a, passes through the heat exchanger for heat appliances 38 and the heat exchanger for reheating baths 42, and uses the heat utilization circulation flow. The thermal energy of the hot water circulating in the path 8 is released, and the hot water and the heat medium circulating in the heating-side circulation flow path 70 and the like are heat exchange heated. The hot water and the heat medium heat-exchanged and heated in the heat exchanger for heat appliance 38 and the heat exchanger for reheating bath 42 are supplied to the heating terminals 63a and 63b and the bathtub and used as a heat source.

(Hot water tank reheating mode)
The hot water tank reheating mode is an operation mode in which the temperature of hot water in the hot water storage tank 10 is raised using the hot water supply device 31.
That is, it is desirable that the hot water in the hot water storage tank 10 is kept at a high temperature for a certain period for sterilization. In the hot water tank reheating mode, the temperature of hot water in the hot water storage tank 10 is set to a considerably high temperature by using the hot water supply device 31, and the inside is sterilized.

When the cogeneration system 1 operates in the hot water tank reheating mode, a water flow is generated as shown by a thick line or an arrow in FIG.
That is, when the cogeneration system 1 operates in the hot water tank reheating mode, the three-way valve 26 is in a state where the opening a and the opening c are in communication.
That is, the suction side of the heat circulation pump 15 and the heat recovery / heat utilization second short circuit 17 are in communication with each other.
The other three-way valve 28 may be in any posture.
The on-off valve 23 provided on the downstream side of the heat exchanger for heat appliance 38 and the on-off valve 24 provided on the downstream side of the heat exchanger 42 for reheating a bath may be either open or closed.
The on-off valve 34 provided in the high temperature hot water short circuit 19 is opened.

Further, when operating in the hot water tank reheating mode, the exhaust heat recovery pump 25 in the power generator 2 is stopped. The heat circulation pump 15 of the heat utilization circulation channel 8 is operated. The hot water supply device 31 is burned.
As a result, the heat circulation pump 15, the hot water supply device 31, the high temperature hot water short circuit 19, the open / close valve 34, the hot water passage 52, the top connection part 11 b of the storage tank 10, the bottom connection part 12 a of the storage tank 10, the heating forward flow path 21. A series of annular flow paths that open to the heat recovery / heat utilization second short circuit 17, the opening c and opening a of the three-way valve 26, and the heat circulation pump 15 are opened, and a water flow is generated in the annular flow path.

Therefore, cold water is extracted from the bottom side of the storage tank 10, heated and heated by the hot water supply device 31, and returned to the storage tank 10 from the upper side.
As a result, the inside of the storage tank 10 is boiled and sterilized.

In the embodiment described above, the three-way valves 28 and 26 are attached to the feed water short circuit 18 and the heat recovery / heat utilization second short circuit 17, respectively. However, the present invention is not limited to this configuration, and the respective positions. Alternatively, two two-way valves may be provided to switch the flow path.
In addition, even when the three-way valve 28 provided in the water supply short-circuit path 18 is replaced with the two-way valve 81 and the water supply short-circuit path 18 is eliminated as shown in FIG. 14, operation in the storage / hot water / heating reheating mode is possible. In addition, the hot water flowing through each flow channel is not mixed, and the flow rate change of the other flow channel and the temperature change of the hot water are not caused by the presence or absence of the flow of the other flow channel.
Therefore, the amount and temperature of the hot water flowing through the exhaust heat recovery circulation channel 7 do not change depending on whether or not another operation mode is executed during the storage mode, and the fuel cell is operated smoothly. It will not be out of range.

  However, when the two-way valve 81 is employed as shown in FIG. 14, there is a problem that the operation in the above-described hot water supply apparatus single hot water supply mode cannot be performed.

Similarly, even if the three-way valve 26 provided in the heat recovery / heat utilization second short circuit 17 as shown in FIG. 15 is replaced with the two-way valve 82, operation in the storage / hot water supply / heating reheating mode is possible, and The hot water flowing through each flow channel is not mixed, and the flow rate change of the other flow channel and the temperature change of the hot water are not caused by the presence or absence of the flow of the other flow channel.
Therefore, the amount and temperature of the hot water flowing through the exhaust heat recovery circulation channel 7 do not change depending on whether or not another operation mode is executed during the storage mode, and the fuel cell is operated smoothly. It will not be out of range.

  However, when the two-way valve 82 is employed as shown in FIG. 15, there is a problem that the operation in the heating / reheating mode using the hot water tank heat cannot be performed.

In the above-described embodiment, the heat-use circulation channel 8 is provided with the heat exchanger for heating equipment and the heat exchanger for bathing, but it may have only one of them. It is also conceivable to provide the hot water supply device with a function of sending a heat medium to the heating device or a function of reheating.
FIG. 16 is an operation principle diagram showing an example in which a water heater is provided with a reheating function. In the cogeneration system 1 shown in FIG. 16, a reheating heat exchanger 45 is mounted on the hot water supply device 31, and a recirculation circulation channel 71 is connected to the heat exchanger 45.

  Each of the above-mentioned cogeneration systems 1 is a cogeneration system that uses a fuel cell, and has a function of supplying heat to a chasing of a bath, a floor heater, etc. in addition to hot water supply, and is a component compared to the conventional one. There are few points.

1 Cogeneration system 2 Power generator (main heat source)
3 Heat recovery device 5 Heat generating part 6 Heat exchanger (heat exchanger for heat recovery)
7 Waste heat recovery circulation flow path 8 Heat utilization circulation flow path 9 Hot water supply flow path 10 Storage tank 11a, 11b Top connection part 12a. 12b Bottom connection portion 15 Thermal circulation pump 17 Heat recovery / heat utilization second short circuit 18 Water supply short circuit 19 High temperature hot water short circuit 20 Tank bypass circulation channel 21 Heating side channel 22 Heating return channel 23 Open / close valve 24 Open / close Valve 25 Waste heat recovery pump 26 Three-way valve 28 Three-way valve 31 Water heater (auxiliary heat source machine)
33 Water inlet 34 On-off valve 35 Heat recovery / heat use first short circuit 38 Heat exchanger for heat appliance (heat exchanger for heat supply)
41 Burner 42 Heat exchanger for bathing (heat exchanger for heat supply)
44 Hot water outlet 50 Water supply passage 52 Hot water passage 70 Heating circulation passage 71 Recirculation circulation passage

Claims (9)

  A main heat source device having a fuel cell and a heat exchanger for recovering heat generated by the fuel cell, an auxiliary heat source device having a larger calorific value per unit time than the main heat source device, and temperature stratification were formed A storage tank for storing hot water in the interior, a heat exchanger for supplying heat to external devices, a water inlet for receiving water supply from the outside, and a hot water outlet for discharging hot water to the outside. And an exhaust heat recovery circulation passage that has a pipe connecting them, a valve and a pump, and is connected in an annular shape including the heat recovery heat exchanger and the storage tank by opening and closing the valve. A heat-use circulation flow path that includes an auxiliary heat source device and a heat exchanger for heat supply and is connected in an annular shape, and a hot water supply flow path that is connected from a water inlet to a hot water outlet via a storage tank, and 3 channels can be connected directly or via other channels or members In the connected cogeneration system, water can be simultaneously passed through the exhaust heat recovery circulation channel, the heat utilization circulation channel and the hot water supply channel, and at the same time when water is simultaneously passed through the three channels, The cogeneration system is characterized in that water flow between the exhaust heat recovery circulation channel and other channels is substantially blocked by opening and closing or pressure balance between the channels.   The exhaust heat recovery circulation channel and the heat utilization circulation channel are connected by a plurality of short circuit paths, and the plurality of short circuits are used when water is simultaneously passed through the exhaust heat recovery circulation channel, the heat utilization circulation channel, and the hot water supply channel. The passages are closed by valves except for one short circuit, and the valves are closed so that both the exhaust heat recovery circulation passage and the heat utilization circulation passage are shut off from the outside. The cogeneration system according to claim 1.   A first heat recovery / heat utilization short-circuit path connecting a part of the exhaust heat recovery circulation path and a part of the heat utilization circulation path, and another part of the exhaust heat recovery circulation path and the heat utilization circulation path. A heat recovery / heat utilization second short circuit connecting another part, and heat recovery for intermittently passing water to the heat recovery / heat utilization first short circuit or the heat recovery / heat utilization second short circuit The cogeneration system according to claim 2, further comprising a heat-use on / off valve.   It has a waste heat recovery pump that generates a water flow in the exhaust heat recovery circulation flow path, and a heat circulation pump that generates a water flow in the heat use circulation flow path. The heat recovery / heat utilization second short circuit is located between the discharge side and the heat circulation pump suction side, and the heat recovery / heat utilization on / off valve is located between the discharge side of the heat circulation pump and the suction side of the exhaust heat recovery pump. 4. The cogeneration system according to claim 3, wherein water is intermittently passed through the heat recovery / heat utilization second short circuit.   The heat recovery / heat utilization first short circuit, a part of the heat utilization circulation channel, and the flow path including the heat recovery / heat utilization second short circuit enter the heat recovery heat exchanger without passing through the storage tank. The cogeneration system according to any one of claims 3 to 4, wherein a tank bypass circulation passage connecting the side and the water discharge side is formed.   The heat recovery / heat utilization on / off valve is a three-way valve with three openings. One of the three-way valve openings is connected to the heat recovery / heat utilization second short circuit, and the remaining two openings are exhaust heat recovery circulation channels. The three-way valve is connected in the middle, and the heat recovery / heat utilization second short circuit and the one in the exhaust heat recovery circulation passage are allowed to pass water and the other water is shut off, and the heat recovery・ A condition that allows water to flow between the second short circuit path using heat and the other one in the exhaust heat recovery circulation path and shuts off the other water flow; The cogeneration system according to claim 5, wherein the cogeneration system can be selected from a state of blocking and allowing water flow in the exhaust heat recovery circulation channel.   Heat utilization / hot water short-circuit path connecting the downstream side of the auxiliary heat source machine and the hot water supply flow path in the heat utilization circulation path, and heat utilization / hot water supply path intermittently passing water between the downstream side of the auxiliary heat source machine and the hot water supply path The cogeneration system according to any one of claims 1 to 6, wherein the cogeneration system has an on-off valve and is capable of flowing hot water heated by an auxiliary heat source device through a hot water supply channel.   It has a water inlet / heat recovery path short-circuit section connecting the water inlet and the exhaust heat recovery circulation flow path, and a water intake / heat recovery path open / close valve that intermittently connects the water flow between the water intake and the exhaust heat recovery circulation flow path. A cogeneration system according to any one of claims 2 to 7.   The water inlet / heat recovery path on / off valve is a three-way valve, which allows water to flow between the water inlet and the exhaust heat recovery circulation flow path, shuts off water flow in the exhaust heat recovery circulation flow path, 9. The cogeneration system according to claim 8, wherein a state in which water flow between the exhaust heat recovery circulation channels is blocked and water flow in the exhaust heat recovery circulation channels is allowed can be selected.

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