JP6509082B2 - Co-generation system - Google Patents

Description

  The present invention heats a heat medium to a preset heating heat medium temperature set in advance, and can execute a heating operation capable of guiding a heated heat medium to a heating radiator in a heating medium circulation path for heating; A cogeneration unit generating electric power and heat, a cooling water circulation passage circulating cooling water collecting heat generated by the cogeneration unit, a hot water circulation passage circulating hot water stored in a hot water storage tank, a cooling water circulation passage The present invention relates to a cogeneration system including an exhaust heat recovery heat exchanger that exchanges heat between cooling water flowing therethrough and water flowing through a water circulation path, and a control unit that controls operation.

The cogeneration system usually includes a power generating device driven by a gas engine (hereinafter sometimes referred to as an engine driven generator) or a heat and power supply unit constituted by a fuel cell or the like. The hot water is heated using heat generated when power is generated, and the heated hot water is stored in the hot water storage tank.
To add an explanation, as a cogeneration system, a cooling water circulation passage for circulating cooling water from which heat generated by the cogeneration unit is collected, and a hot water circulation passage for taking out hot water in the lower portion of the hot water storage tank and returning it to the upper portion of the hot water storage tank An exhaust heat recovery heat exchanger that exchanges heat between cooling water circulating in the cooling water circulation path and hot water circulating in the hot water circulation path, a cooling water pump circulating cooling water in the cooling water circulation path, hot water in the hot water circulation path It is known to have a circulating hot and cold water pump.
In the hot water circulation path, a hot water bypass path capable of circulating hot water in a manner to bypass the hot water storage tank in the hot water circulation path is provided, and a connecting portion of the hot water circulation path and the hot water bypass path A three-way valve capable of adjusting the flow rate ratio of hot water flowing through the side and the side of the hot water bypass passage is provided, and the temperature of hot water stored in the hot water storage tank is adjusted by adjusting the flow rate by the three-way valve Is configured to be controlled to the target hot water storage temperature.
In the said structure, when storing the heat which generate | occur | produced in the cogeneration part to a hot water storage tank, while making a cogeneration part drive, a cooling water pump is made to work and a cooling water is circulated to a cooling water circulation passage, The hot water operation is performed by circulating hot water in the hot water circulation path and recovering the exhaust heat held by the cooling water to the side of the hot water with an exhaust heat recovery heat exchanger.

Furthermore, in the technology disclosed in Patent Document 1, a heat medium circulation path that circulates the heat medium to a heating radiator such as a floor heating facility and a heat that pumps the heat medium circulating the heat medium circulation path to the cogeneration system. It is known to have a medium pump and a heat source unit for heating the heat medium circulating in the heat medium circulation path.
To add the description, in the technology disclosed in Patent Document 1, the cooling water circulating through the cooling water circulation path after flowing through the exhaust heat recovery heat exchanger and before flowing through the cogeneration unit flows through the heat medium circulation path. A heat exchanger for heating is provided to exchange heat with the heating medium, and the heat medium that has been heated by the heating heat exchanger and heated by the heat source machine flows to the heating radiator The heating operation is performed.
Furthermore, in the technology disclosed in Patent Document 1, as one form of heating operation, the hot water pump is operated to circulate hot water in the hot water circulation path, and a part of the exhaust heat with the exhaust heat recovery heat exchanger. While collecting the hot water in the hot water storage tank and using the remaining part of the exhaust heat for heating, a heating operation (operation to execute the heating operation and the hot water storage operation in parallel) for storing a part of the exhaust heat is performed. It is configured to be executable.

JP, 2014-142117, A

In the technology disclosed in the above-mentioned Patent Document 1, as shown in the paragraph [0066], during hot water storage operation, the hot water temperature (so-called hot water temperature) before flowing into the hot water storage tank in the hot water circulation path is The ratio of the hot and cold water recirculated to the upstream side of the exhaust heat recovery heat exchanger is controlled by controlling the opening degree of the above-mentioned three-way valve so as to be 75 ° C. to perform the hot water storage operation. In the heating operation for storing a part of the heat, as shown in the [0076] to [0077] stages thereof, the exhaust heat recovery heat exchanger such that the temperature of the heat medium of the heating heat exchanger becomes the target temperature. The hot water operation is performed by controlling the flow rate of flowing hot and cold water.
In such a control mode, the control for the hot water storage operation differs depending on the presence or absence of the heating operation, and the flow rate of the heat medium may become zero even during the heating operation. Therefore, the presence or absence of the flow rate of the heat medium is detected. There is a problem that there is a lot of information that needs to be acquired in control, the structure is complicated, and the control is also complicated.
In the heating heat exchanger, the cooling water circulating through the cooling water circulation path after flowing through the exhaust heat recovery heat exchanger and before flowing through the cogeneration unit and the heat medium flowing through the heat medium circulation path are Because it is provided to be replaced, in the heating operation (operation in which the heating operation and the hot water storage operation are performed in parallel) that stores a part of the exhaust heat, the recovered heat amount recovered by the exhaust heat recovery heat exchanger Since it is necessary to adjust while taking into consideration the heating load, and the control of the hot water storage operation (operation related to exhaust heat recovery) is complicated, improvement is desired.

  The present invention has been made in view of the above problems, and its object is to operate the hot water with simple configuration and simple control which do not need to be switched according to the presence or absence of heating operation and the presence or absence of the flow rate of the heat medium. To provide a cogeneration system capable of

The cogeneration system to achieve the above purpose is
A heat source machine capable of performing a heating operation of heating a heat medium to a preset heating heat medium temperature set in advance and guiding the heated heat medium to a heating radiator through a heating medium circulation path for heating;
Cogeneration unit that generates electricity and heat,
A cooling water circulation path for circulating cooling water for recovering heat generated by the cogeneration unit;
Hot water circulation path which circulates hot water stored in hot water storage tank,
An exhaust heat recovery heat exchanger that exchanges heat between the cooling water flowing through the cooling water circulation path and the hot water flowing through the hot water circulation path;
A cogeneration system comprising a control unit for controlling operation, the characteristic configuration of which is as follows:
A heat medium bypass passage which flows through a part or all of the heat medium of the heat medium circulation passage after the heating radiator and before the heat source machine;
Heat exchange for heating which exchanges heat between the cooling water in the cooling water circulation path after flowing through the cogeneration unit and before flowing through the exhaust heat recovery heat exchanger and the heat medium flowing through the heat medium bypass path Equipped with
When the cooling water is in an intermediate temperature or high temperature state while the control unit is performing cooling water circulation control for circulating the cooling water in the cooling water circulation path, the heat medium in the heat medium circulation path and the heat medium bypass The heat medium distribution flow rate control for controlling the heat medium distribution flow rate to the heat medium bypass passage is performed such that the heat medium junction temperature on the downstream side where the heat mediums of the paths merge is equal to the set heating heat medium temperature. When the cooling water is in a high temperature state, the flow rate control of hot and cold water flowing through the exhaust heat recovery heat exchanger so that the hot water flowing through the exhaust heat recovery heat exchanger becomes a target temperature for storing hot water The point is to carry out.

According to the above feature configuration, in the heat medium distribution flow control for controlling the heat medium distribution flow to the heat medium bypass, the hot water flow control for controlling the flow of hot water using the heat medium merging temperature of the heat medium circulation as a parameter. Since control is performed using the temperature of hot water flowing through the waste heat recovery heat exchanger in the hot water circulation path as a parameter, it is not necessary to obtain information related to the presence or absence of heating operation and the flow of heat medium, Configuration can be simplified. Furthermore, since it is not necessary to switch the hot and cold water flow control depending on the presence or absence of the heating operation and the presence or absence of the flow rate of the heat medium, storage control can be realized with simple control both during execution and stop of the heating operation.
To add the description, according to the control according to the above characteristic configuration, the control unit sets the heat medium merging temperature if the cooling water becomes medium temperature or high temperature regardless of the presence or absence of the heating operation and the presence or absence of the heat medium flow rate. By controlling the heat medium distribution flow rate to the heat medium bypass passage so as to reach the heating heat medium temperature, the heating medium of the set heating heat medium temperature can be introduced to the heating radiator and the heating operation can be appropriately performed. In addition, when the cooling water is high temperature and exhaust heat is sufficient, part of the exhaust heat can be stored in the hot water storage tank.
Further, in the above-mentioned characteristic configuration, the heating heat exchanger is a heat medium which flows through the heat medium bypass passage and the cooling water after flowing through the cogeneration unit and before flowing through the exhaust heat recovery heat exchanger. And heat exchange, so even if the cooling water is in a high temperature state and heating operation and hot water storage operation are simultaneously performed, waste heat is prioritized over heating without performing complicated control. It is possible to use the rest of the exhaust heat for storing hot water and to simplify the hot water storage control.
According to the above invention, it is possible to realize a simple configuration that does not need to be switched according to the presence or absence of the heating operation and the presence or absence of the flow rate of the heat medium, and a cogeneration system capable of executing the hot water storage operation with simple control.

Further features of the cogeneration system are:
The control unit controls the heat medium distribution flow rate to the heat medium bypass passage to zero when the cooling water is in a low temperature state with the cooling water circulation control in which the cooling water is circulated in the cooling water circulation path. The point is to execute the heat medium distribution flow control.

  According to the above feature configuration, when the cooling water is in a low temperature state, the return temperature of the cooling water to the cogeneration unit can be quickly set, for example, to a temperature higher than the lower limit temperature necessary for the cogeneration unit. Good protection of the

The cogeneration system to achieve the above purpose is
A heat source machine capable of performing a heating operation of heating a heat medium to a preset heating heat medium temperature set in advance and guiding the heated heat medium to a heating radiator through a heating medium circulation path for heating;
Cogeneration unit that generates electricity and heat,
A cooling water circulation path for circulating cooling water for recovering heat generated by the cogeneration unit;
Hot water circulation path which circulates hot water stored in hot water storage tank,
An exhaust heat recovery heat exchanger that exchanges heat between the cooling water flowing through the cooling water circulation path and the hot water flowing through the hot water circulation path;
A cogeneration system comprising a control unit for controlling operation, the characteristic configuration of which is as follows:
A cooling water bypass passage that flows through all or part of the cooling water of the cooling water circulation passage after flowing through the cogeneration unit and before flowing through the exhaust heat recovery heat exchanger;
A heating heat exchanger is provided which exchanges heat between the heat medium in the heat medium circulation path after the flow of the heating radiator and before the heat source machine and the cooling water flowing through the cooling water bypass path. ,
In the state where the control unit is performing a cooling water circulation control that circulates the cooling water in the cooling water circulation path, when the cooling water is in an intermediate temperature or high temperature state, the heat medium flowing through the heating heat exchanger The cooling water distribution flow rate control for controlling the cooling water distribution flow rate to the cooling water bypass passage is executed so that the temperature becomes the set heating heat medium temperature, and the exhaust heat recovery is performed when the cooling water is in a high temperature state The point is to execute hot and cold water flow control for controlling the flow rate of hot and cold water flowing through the exhaust heat recovery heat exchanger so that the hot and cold water flowing through the heat exchanger becomes the target hot water storage temperature.

According to the above feature configuration, in the cooling water distribution flow control for controlling the cooling water distribution flow to the cooling water bypass path, the temperature of the heat medium flowing through the heating heat exchanger is used as a parameter to control the hot water flow In the control of hot and cold water flow, control is performed using the temperature of hot and cold water flowing through the exhaust heat recovery heat exchanger in the hot and cold water circulation path as a parameter, so information related to the presence or absence of heating operation and the presence or absence of the flow rate of heat medium is acquired There is no need for this, and the configuration can be simplified. Furthermore, since it is not necessary to switch the hot and cold water flow control depending on the presence or absence of the heating operation and the presence or absence of the flow rate of the heat medium, storage control can be realized with simple control both during execution and stop of the heating operation.
To add the description, according to the control according to the above characteristic configuration, the control unit generates the heating heat exchanger if the cooling water is at a medium temperature or a high temperature regardless of the presence or absence of the heating operation and the presence or absence of the heat medium flow rate. The cooling water distribution flow rate to the cooling water bypass is controlled so that the temperature of the flowing heat medium becomes the set heating heat medium temperature, and the heat medium of the set heating heat medium temperature is guided to the heating radiator and heated appropriately Can run. In addition, when the cooling water is high temperature and exhaust heat is sufficient, part of the exhaust heat can be stored in the hot water storage tank.
Furthermore, in the above-mentioned characteristic configuration, the heating heat exchanger comprises the cooling water flowing through the cooling water bypass passage after flowing through the cogeneration unit and before flowing through the exhaust heat recovery heat exchanger; Since heat exchange is performed with the heat medium flowing through the circulation path, complex control is not performed even when the heating operation and the hot water storage operation are simultaneously performed when the cooling water is in a high temperature state. The waste heat can be used in preference to heating, and the rest of the waste heat can be used for hot water storage, and storage water control can be simplified.
According to the above invention, it is possible to realize a simple configuration that does not need to be switched according to the presence or absence of the heating operation and the presence or absence of the flow rate of the heat medium, and a cogeneration system capable of executing the hot water storage operation with simple control.

Further features of the cogeneration system are:
The control unit controls the cooling water distribution flow rate to the cooling water bypass passage to zero when the cooling water is in a low temperature state while performing the cooling water circulation control of circulating the cooling water in the cooling water circulation path. The point is to execute the cooling water distribution flow control.

  According to the above feature configuration, when the cooling water is in a low temperature state, the return temperature of the cooling water to the cogeneration unit can be quickly set, for example, to a temperature higher than the lower limit temperature necessary for the cogeneration unit. Good protection of the

Schematic configuration diagram showing the main configuration of a cogeneration system and a heat source unit The figure which shows the hot water flowing state at the time of the hot-water supply driving | operation in 1st Embodiment. The figure which shows the hot water circulation state at the time of the hot water storage driving | operation in 1st Embodiment, and a cooling water circulation state The figure which shows the cooling water circulation state at the time of the heating operation which does not store exhaust heat in 1st Embodiment, and a heat-medium circulation state. The figure which shows the hot water circulation state at the time of heating operation which heat-stores a part of waste heat in 1st Embodiment, a cooling water circulation state, and a heat medium circulation state Control flow according to the cooling water temperature determination in the first embodiment Control flow according to the heating operation in the first embodiment Control flow according to the hot water storage operation in the first embodiment The figure which shows the hot water flowing state at the time of the hot-water supply driving | operation in 2nd Embodiment The figure which shows the hot water circulation state at the time of the hot water storage driving | operation in 2nd Embodiment, and a cooling water circulation state The figure which shows the cooling water circulation state at the time of the heating operation which does not store exhaust heat in 2nd Embodiment, and a heat-medium circulation state. The figure which shows the hot water circulation state at the time of heating operation which heat-stores a part of exhaust heat in 2nd Embodiment, a cooling water circulation state, and a heat medium circulation state Control flow according to the heating operation in the second embodiment

The cogeneration system 100 according to the embodiment of the present invention relates to a simple configuration that does not need to be switched according to the presence or absence of heating operation and the flow rate of the heat medium H, and one capable of executing the hot water storage operation with simple control. .
Hereinafter, the cogeneration system 100 heats the heat medium to the preset heating heat medium temperature set in advance, and heats and dissipates the heated heat medium in the heating circulation path 34 (concept included in the heat medium circulation path). Since the heat source unit 10 for performing the heating operation leading to the unit 33 is provided, first, the heat source unit 10 will be described first, and then the cogeneration system main body 40 will be described.

First Embodiment
[Heat source machine]
The heat source unit 10 is configured as a general hot water supply heater, although details will be described later, as shown in FIG. 1, and the hot water W supplied from the tap water via the heat source unit side water inlet 20a is preset The heating circulation path 34 (concept included in the heat medium circulation path) which performs so-called hot water supply operation by heating to the set hot water supply temperature and supplying it to the hot water supply plug 30 and circulating the heated heat medium H to the heating radiator 33 The heating operation is performed to heat the heat medium H flowing therethrough.
As an external interface, a heat source unit side water inlet 20a provided on one end side of the upper water pipe 20 and taking in hot water W from the outside to the upper water pipe 20, and provided on the other end side of the same upper water pipe 20 The heat source side water discharge unit 20b that discharges the hot water W to the outside, the heat source side heat medium receiving unit 16a that receives the heat medium H of the heat medium flow path 16 from the outside, and the heat medium H of the heat medium flow path 16 to the outside A heat source unit-side heat medium discharge unit 16b to be discharged, a fuel gas supply unit 14 that takes in a fuel gas G that is a natural gas-based city gas, and the like are provided.
The heat source side water outlet 20 b is connected to the hot water supply plug 30 so that the hot water W discharged from the heat source side water outlet 20 b is supplied to the hot water supply tap 30.
In addition, the heat source unit side heat medium receiving unit 16a and the heat source unit side heat medium discharge unit 16b are configured to circulate the heat medium H circulating through the heating circulation path 34 provided between it and the heating radiator 33 such as a hot water floor heating panel. It is connected to the heating circuit 34 in the form of taking in or discharging. The heating circulation path 34 is a heating radiator having a predetermined flow rate provided to the heating circulation path 34 via the forward header 31 among the total amount of the heat medium H discharged from the heat source unit side heat medium discharge unit 16 b. 33, while the heat medium H supplied to the heating radiator 33 flows through the return header 32 and guides the entire amount of the heat medium H flowing through the return header 32 to the cogeneration system main body 40 The heat medium flow path 104 (concept included in the heat medium circulation path) is disposed so as to flow back to the heat source unit side heat medium receiving unit 16a.

The heat source unit 10 is provided with a heat source unit side control unit 25 comprising a computer that controls the operation of the burners 11a and 12a described later and controls the operation of various accessories such as other valves and pumps. .
The heat source unit side control unit 25 is configured to be communicable with the remote control 27 installed in the house through the communication unit 26. With this configuration, the set hot water supply temperature at the time of hot water supply from the remote control 27 and the heating operation Start and stop can be operated. The communication unit 26 is also configured to be capable of two-way communication by wireless or wire communication with the communication unit 96 on the side of the cogeneration system main unit 40 described later.

The heat source unit 10 is a hot water supply heating unit 11 for heating the hot water W taken into the heat source unit side water inlet unit 20a and discharged from the heat source unit side water outlet unit 20b, and taken into the heat source unit side heat medium receiving unit 16a. And a heating heating unit 12 for heating the heat medium H discharged from the machine-side heat medium discharge unit 16b.
The hot water supply heating unit 11 heats the heat of the burner 11a that burns the fuel gas G supplied via the adjustment valve 11c with the combustion air supplied by the fan 13, and the high temperature combustion gas discharged from the burner 11a. The hot water supply heat exchanger 11 b is configured to heat the hot water W flowing through the upper water pipeline 20 by replacement.
On the other hand, the heating heating unit 12 includes a burner 12a that burns the fuel gas G supplied via the adjusting valve 12c with the combustion air supplied by the fan 13, a high temperature combustion gas discharged from the burner 12a, And a heating heat exchanger 12b for heating the heat medium H flowing through the heat medium flow passage 16 by the heat exchange.

In addition, the third water temperature sensor 21 for detecting the temperature of the hot water W taken from the heat source side water inlet 20a (hereinafter sometimes referred to as "the heat source side incoming water temperature") in the upper water pipeline 20; The fourth temperature sensor 22 for detecting the temperature of the hot water W discharged from the side water discharge portion 20b (hereinafter sometimes referred to as "heat source side water discharge temperature"), and the water flow switch 23 for detecting the flow of the water W Is arranged.
On the other hand, the heat medium flow path 16 detects the temperature of the heat medium H taken from the heat source unit-side heat medium receiving unit 16 a (hereinafter sometimes referred to as “heat source unit-side heat input temperature”). A sensor 17, a second temperature sensor 18 for detecting the temperature of the heat medium H discharged from the heat source unit side heat medium discharge unit 16b (hereinafter sometimes referred to as "heat source unit side heat output medium temperature"), and a heat medium A heat medium pump 19 for delivering H is disposed.

  With such a configuration, the heat source side controller 25 heats the hot water W supplied from the heat source side water inlet 20a to the set hot water supply temperature previously set by the remote control 27 and supplies it to the hot water supply plug 30 In the heating operation, the heating operation of heating the heat medium H circulating in the heating circuit 34 provided between the heating radiator 33 and the heating radiator 33 to a preset target temperature can be performed. The details of the hot water supply operation and the heating operation will be added below.

(Hot water supply operation)
In the hot water supply operation, the heat source side water input temperature detected by the third temperature sensor 21 in a state where the flow of hot water W by opening the hot water supply plug 30 is detected by the water flow switch 23 disposed in the upper water pipe 20. Is lower than the set hot water supply temperature, the fuel gas G is burned by the burner 11a. Also, in this hot water supply operation, the adjustment valve 11 c adjusts the amount of fuel gas G supplied with the amount of combustion in the burner 11 a so that the heat source side water discharge temperature detected by the fourth temperature sensor 22 becomes the set hot water supply temperature. It is adjusted by the opening control of.
Therefore, when the hot water supply plug 30 is opened, the hot water supply operation is appropriately performed, and the hot water W of the set hot water supply temperature is supplied to the hot water supply plug 30.

Furthermore, a bypass control valve 24 is provided in the upper water pipeline 20 so as to connect the upstream side and the downstream side of the hot water supply heat exchanger 11 b.
In the hot water supply operation, in addition to controlling the flow rate of gas and adjusting the amount of combustion in the burner 11a by the opening degree control of the adjusting valve 11c as described above, the opening degree control of the bypass adjusting valve 24 controls the bypass flow rate By precisely controlling, the outlet temperature of the hot water supply can be controlled more accurately to the set temperature.

(Heating operation)
In the heating operation, the start button of the heating operation in the remote control 27 is pressed to start the operation of the heat medium pump 19 disposed in the heat medium channel 16 and the heat medium H flows through the heat medium channel 16 In the state, when the heat source unit-side heat input temperature detected by the first temperature sensor 17 is lower than the target temperature, the fuel gas G is burned by the burner 12a. In the heating operation, the combustion state of the burner 12a can execute the flow rate control of the fuel gas G so that the heat source unit side heat output medium temperature detected by the second temperature sensor 18 becomes the target temperature. The fuel gas G is controlled by the opening degree control of the control valve 12 c which can switch the supply start / stop state of the fuel gas G.

[Cogeneration system main body]
Next, the cogeneration system main body 40 will be described based on FIGS.
2 to 5 show various operation states of the cogeneration system main body 40. The pipes through which the hot water W, the cooling water C, or the heat medium H flows are indicated by thick solid lines, The piping through which the fluid does not flow is indicated by a thin solid line.
The cogeneration system main body 40 has a main body side water inlet 80a for taking in the hot water W from the water supply as an external interface, a main body side water outlet 78a for discharging the hot water W to the heat source machine 10 side, and a hot water storage tank 90. A drain valve 75 for draining, a main body side heat medium receiving portion 58a for taking in the heating heat medium H from the heat source unit 10 side, and a main body side heat medium discharge portion 58b for discharging the heating medium H to the heat source unit 10 side are provided. ing.
Furthermore, a heat and power supply unit 41 provided on the side of the cogeneration system main body 40 and a main body side control unit 95 (an example of a control unit) comprising a computer for controlling the operation of various accessories such as valves and pumps are provided. . The main body side control unit 95 performs two-way wireless or wired communication with the communication unit 26 on the heat source device 10 side via the communication unit 96 or a display unit (not shown) provided outside. Communication is performed to perform predetermined display such as an operating state.
Specifically, although the details will be described later, for the communication unit 26 of the heat source unit 10 to the communication unit 96 of the cogeneration system main body 40, the target of the set hot water supply temperature set in the heat source unit 10 or the heating operation The temperature is output.

  The cogeneration system main body 40 includes a heat and power supply unit 41 that generates power and heat such as an engine driven generator, and the generated power is appropriately connected to commercial power using an inverter or the like as an external unit. Power supply etc. Moreover, the heat which the cogeneration part 41 generate | occur | produced is utilized for the heating of the hot water W, and the hot water storage tank 90 which stores this heated hot water W is provided.

The cogeneration unit 41 has a structure cooled by a cooling water C flowing through a cooling water jacket (not shown) provided therein, and a cooling water circulation path 42 through which the cooling water C circulates is provided. .
In the cooling water circulation path 42, a cooling water pump 46 for feeding the cooling water C along the circulating direction of the cooling water C, a solenoid valve 47 capable of interrupting the flow of the cooling water, and a cooling water jacket in the cogeneration unit 41 (shown Omitted), the sixth temperature sensor 50 for detecting the temperature of the cooling water C discharged from the cooling water jacket, the heating heat exchanger 56, the exhaust heat recovery heat exchanger 55, and the buffer for temporarily storing the cooling water C The tanks 51 are arranged in the order described.
The buffer tank 51 is provided with a fifth temperature sensor 49 that detects the temperature of the cooling water C temporarily stored. In addition, the hot and cold water W supplied to the main body side water receiving section 80 a is appropriately replenished to the buffer tank 51 as the cooling water C through the hot and cold water replenishment flow path 105 and the solenoid valve 52.
Further, an eighth temperature sensor 54 for detecting the temperature of the cooling water C is provided on the downstream side of the exhaust heat recovery heat exchanger 55 and on the upstream side of the buffer tank 51.

The exhaust heat recovery heat exchanger 55 is configured to perform heat exchange between the cooling water C flowing through the cooling water circulation path 42 and the hot water W flowing through the heating water storage circulation path 60. On the other hand, the heating heat exchanger 56 is configured to perform heat exchange between the cooling water C flowing through the cooling water circulation passage 42 and the heat medium H flowing through the main body side heat medium passage 104. .
That is, when the cooling water pump 46 is operated to circulate the cooling water C in the cooling water circulation path 42 in a state where heat is generated in the cogeneration part 41, the cooling that has flowed through the cogeneration part 41 and is heated The water C exchanges heat with the heat medium H and the hot water W by flowing through the heating heat exchanger 56 and the exhaust heat recovery heat exchanger 55, and is supplied again to the cogeneration unit 41. Become.

The hot water storage tank 90 is configured as a closed tank in which the hot water W is supplied to the lower portion 90 b and the hot water W is taken out from the upper portion 90 a to the main body side water discharge portion 78 a. Further, the hot water W taken out from the lower portion 90b of the hot water storage tank 90 is allowed to flow through the exhaust heat recovery heat exchanger 55 so as to be heated by the heat generated by the cogeneration unit 41 and returned to the upper portion 90a of the hot water storage tank 90 The heating and storing hot water circulation path 60 which circulates the hot and cold water W is provided.
The heated water storage circulation passage 60 is connected to the lower portion 90 b of the hot water storage tank 90 through the three-way valve 73 to the bottom pipe passage 72 connected to the lower portion 90 b. The upper portion 90 a is connected to the upper conduit 66 connected to the upper portion 90 a via a proportional valve 65.

  A three-way valve 73, a hot water pump 61 for sending hot water W, an exhaust heat recovery heat exchanger 55, and the exhaust heat recovery heat exchanger 55 flow through the heating storage circulation path 60 along the flow direction of the hot water W Ninth temperature sensor 63 for detecting the temperature of hot water W, circulating flow rate sensor 62 for detecting the flow rate of hot water W, temperature of hot water W flowing into the upper portion 90a of the hot water storage tank 90 (hereinafter referred to as "hot water temperature" There is a tenth temperature sensor 64 for detecting a proportional valve 65 and a hot water storage tank 90 arranged in the order described.

Further, the upper pipeline 66 connected to the upper portion 90 a of the hot water storage tank 90 is connected to the main body side water discharge portion 78 a via the hot water / water three-way control valve 77 and the hot water discharge channel 78. The 11th temperature sensor 76 which detects the temperature of the hot water W taken out to the upper pipeline 66 from the upper part 90a of the hot water storage tank 90 is provided in the side. In addition, instead of the eleventh temperature sensor 76, the detection of the tank take-out hot water temperature is the fifteenth temperature sensor 91a provided at the top of the plural fourteenth temperature sensors 91 distributed in the vertical direction of the hot water storage tank 90. You may go there.
Further, a water supply pipe 82 communicating with the main body side water inlet 80a is connected to the hot water / water three-way control valve 77. Further, the hot water discharge conduit 78 and the water supply conduit 82 are connected by a bypass conduit 86, and in the bypass conduit 86, a solenoid valve 87 capable of interrupting the flow of the hot water W is disposed.
That is, the hot water / water three-way adjusting valve 77 mixes the hot water W supplied from the water supply pipe 82 with the mixing ratio adjustment with respect to the hot water W supplied from the upper portion 90a of the hot water storage tank 90 to the main body side water outlet 78a. Act as a possible mixing part.
In addition, on the downstream side of the connection portion of the hot water discharge pipe 78 with the bypass pipe 86, the flow rate sensor 79 for detecting the flow rate of the hot water W is discharged from the main body side water discharge portion 78a The 12th temperature sensor 81 which detects the temperature of hot water W is arrange | positioned in order of description.
On the other hand, on the upstream side of the connection portion between the water supply pipe 82 and the bypass pipe 86, the pressure reducing valve 84 for adjusting the pressure of the hot water W is supplied along the flowing direction of the hot water W A thirteenth temperature sensor 85 for detecting the temperature of the hot water W and a check valve 83 for preventing the backflow of the hot water W are disposed in the order described.

In addition, the water supply pipe 82 is connected to the three-way valve 73 of the bottom pipe pipe 72 connected to the lower portion 90b of the hot water storage tank 90 via the check valve 89. At the same time as the hot water W is taken out from the upper part 90 a, the hot water W is supplied from the lower part 90 b through the water supply pipe 82, the three-way valve 73 and the bottom part pipe 72.
As described above, the heating and storing hot water circulation passage 60 works as a hot and cold water circulation passage.

To add the description regarding the heating circulation path 34, the heating circulation path 34 guides the entire amount of the heat medium H flowing through the return header 32 to the cogeneration system main body 40 (heat medium circulation path The concept is included in
To add the description, the main body side heat medium flow path 104 is disposed in the casing of the cogeneration system main body 40 via the main body side heat medium receiving portion 58a and the main body side heat medium discharge portion 58b, and the heating radiator 33 It is connected to the in-casing main body side heat medium flow path 104a (concept included in the heat medium circulation path) after the flow of (the return header 32) and before the flow of the heat source unit 10 And a heat medium bypass passage 104b for bypassing part or all of the heat medium H flowing through the flow path 104a to the side of the heating heat exchanger 56. A heat medium three-way adjustment valve 113 is provided which can adjust the distribution flow rate of the heat medium H to the side of the main body side heat medium passage 104a and the heat medium bypass passage 104b.
The heat medium which is the heat medium temperature on the downstream side of the portion where the heat medium flowing through both the in-casing main body side heat medium flow path 104a and the heat medium bypass passage 104b merges A sixteenth temperature sensor 102b is provided to detect the junction temperature.
Although the details will be described later, the main body side control unit 95 uses the heat medium three-way adjustment valve 113 to distribute the flow rate of the heat medium H to the side of the heat medium flow passage 104a in the housing and the heat medium bypass passage 104b. The heat medium distribution flow rate control is configured to be performed in the form of adjustment.
Here, in the cogeneration system main body 40 according to the first embodiment, a heat medium pump provided inside the heat source unit 10 without the heat medium pump for pressure-feeding the heat medium H in the housing thereof. The heat medium is circulated at a discharge pressure of 19.

With the above configuration, the cogeneration system 100 according to the first embodiment performs the following hot water supply operation realized by executing the hot water supply control, the cooling water circulation control, the cooling water temperature determination, the hot water flow control And the hot water storage operation and the heating operation which are realized by executing the heat medium distribution flow rate control.
Specifically, in a state where the main body side control unit 95 executes the cooling water circulation control that circulates the cooling water C in the cooling water circulation path 42, when the cooling water C is in an intermediate temperature or high temperature state, the main body side heat medium flow The heat medium joining temperature (temperature detected by the sixteenth temperature sensor 102b) on the downstream side where the heat medium H of the passage 104a and the heat medium H of the heat medium bypass passage 104b join is equal to the set heating heat medium temperature The heat medium distribution flow rate control for controlling the heat medium distribution flow rate to the heat medium bypass passage 104b is executed, and when the cooling water C is in a high temperature state, the hot water flowing through the exhaust heat recovery heat exchanger 55 becomes the hot water target temperature. Thus, the hot water flow control is performed to control the flow rate of hot water flowing through the exhaust heat recovery heat exchanger 55.

Here, the heating operation includes a high temperature heating operation in which the target temperature of the heat source side heat output medium temperature is a high temperature, and a low temperature heating operation in which the target temperature is a low temperature. There are a dash operation, a normal low temperature heating operation, and a floor heating low load operation, and the target temperature in each operation is a different temperature, and the above-mentioned set heating heat medium temperature is a temperature corresponding to the target temperature.
In the following, after the hot water supply control for realizing the hot water supply operation is described, the coolant circulation control, the coolant temperature determination, the hot water flow control, and the heat medium distribution flow rate control for realizing the hot water storage operation and the heating operation will be described.

(Hot water control)
As shown in FIG. 2, in the hot water supply control, the hot water W is supplied from the heat source side water outlet 20 b of the heat source machine 10 to the hot water supply tap 30 by opening the hot water supply tap 30. The hot water W is supplied to the heat-source-unit-side water inlet 20a, and the flow sensor 79 disposed in the hot water discharge passage 78 accordingly detects the flow of the hot water W.
In the hot water supply control, the relatively high temperature water W in the upper layer of the hot water storage tank 90 is taken out from the upper part 90 a to the upper pipe line 66 and is supplied to the hot water pipe 78 via the hot water three way adjustment valve 77.
Furthermore, in this hot water supply control, once the target outflow temperature is determined to be a temperature equal to the set hot water supply temperature at which the input is received from the heat source machine 10 or a temperature slightly higher considering the heat release than the set hot water supply temperature. The opening degree of the hot and cold water three-way adjusting valve 77 is controlled.
That is, when the tank take-out hot water temperature detected by the eleventh temperature sensor 76 is equal to or higher than the target outgoing water temperature, the appropriate hot water W is mixed in the hot water three-way adjustment valve 77, whereby the hot water W at the target outgoing water temperature is The obtained hot water W is supplied to the heat source unit side water inlet 20a of the heat source unit 10.
In the heat source unit 10, if the heat source unit side incoming water temperature is equal to or higher than the set hot water supply temperature, it is not necessary to reheat the hot water W, so the hot water W of this set hot water supply temperature is not heated by the heat source unit 10. Is supplied to the hot-water tap 30 as it is.

On the other hand, if the tank outlet hot water temperature detected by the eleventh temperature sensor 76 is lower than the target outgoing water temperature, the target outgoing water temperature is set to a temperature (eg, 30 ° C.) sufficiently lower than the set hot water supply temperature. The amount of hot water W supplied via the three-way adjusting valve 77 is increased, and the hot water W of the target water discharge temperature set low is discharged from the main body side water discharge portion 78a.
The hot water supply operation is realized in a form in which the above-described hot water supply control is executed.

(Cooling water circulation control)
The cooling water circulation control is to control the circulation state of the cooling water C circulating in the cooling water circulation path 42. In the cooling water circulation control, the main control unit 95 controls the number of rotations of the cooling water pump 46 so that the cooling water C circulates in the cooling water circulation path 42 at a constant flow rate (for example, 5 L / min). The said cooling water circulation control is performed in the form interlocked | cooperated with the operation | movement of the cogeneration part 41. As shown in FIG.

(Cooling water temperature judgment)
The main body side control unit 95 executes the temperature judgment of the cooling water C based on the control flow according to the cooling water temperature judgment shown in FIG. 6 in the state where the above-mentioned cooling water circulation control is being executed.
After setting "low temperature" to the coolant temperature (# 101) as an initial value, main unit-side control unit 95 repeatedly executes the following temperature determinations of # 102 to # 109 during operation of cogeneration unit 41. .
When the cooling water temperature is set to “low temperature” and the detection temperature of the fifth temperature sensor 49 exceeds 66 ° C. (low temperature side middle temperature judgment threshold) (# 102), the main body side control unit 95 is the cooling water Set "medium temperature" to temperature (# 103). If not, do nothing (to # 104).
When the cooling water temperature is set to "medium temperature" and the detection temperature of the fifth temperature sensor 49 is less than 63 ° C. (low temperature determination threshold) (# 104), the cooling water temperature is "Low temperature" is set (# 105). If not, do nothing (to # 106).
If the cooling water temperature is set to “medium temperature” and the detection temperature of the fifth temperature sensor 49 exceeds 73 ° C. (high temperature determination threshold) (# 106), the cooling water temperature “ Set "high temperature"(# 107). If not, do nothing (to # 108).
When the coolant temperature is set to “high” and the detection temperature of the fifth temperature sensor 49 is less than 70 ° C. (medium temperature determination threshold on the high temperature side) (# 108) Set "medium temperature" to temperature (# 109). If not, do nothing (to # 102).

The main body side control unit 95 executes control related to the following heating operation and control related to the hot water storage operation based on the cooling water temperature determined by the above-described cooling water temperature determination.
(Control related to heating operation)
During the operation of the cogeneration unit 41, as shown in the control flow of FIG. 7, the following determination control of # 201 to # 204 is repeatedly executed. When the heating operation is turned on by the remote control 27 and the cooling water temperature is set to "medium temperature" or "high temperature" while the cooling water circulation control is being executed (# 201 And) control the opening degree of the heat medium three-way adjusting valve 113 so that the heat medium merging temperature of the main body side heat medium channel 104 (the detected temperature of the sixteenth temperature sensor 102b) becomes the set heating heat medium temperature (# 202) If not, do nothing (to # 203). Incidentally, in the control of # 201 and # 202, the main body side control unit 95 controls the opening degree (target position) of the heat medium bypass passage 104b side of the heat medium three-way adjusting valve 113 according to the following [Equation 1]. Ru.

  Target position = present position + A (set heating heat medium temperature-heat medium junction temperature) ..... [Equation 1]

  Here, it is assumed that A is a positive constant. In the formula [1], the opening degree of the heat medium bypass passage 104b of the heat medium three-way adjusting valve 113 is controlled to the opening side as the target position is larger.

When the heating operation is turned off by the remote control 27 or the cooling water temperature is “low temperature” (# 203), the main body side control unit 95 side of the heating medium three-way adjustment valve 113 on the heating heat exchanger 56 side The opening degree of is controlled to be fully closed (# 204), otherwise nothing is done (to # 201).
The control of # 201 to # 204 described above corresponds to heat medium flow rate distribution control.

(Control related to hot water storage operation)
During the operation of the cogeneration unit 41, as shown in the control flow of FIG. 8, the following determination control of # 301 to # 304 is repeatedly executed. When the cooling water temperature is "high"(# 301) while the cooling water circulation control is being executed, the main body side control unit 95 detects the temperature detected by the ninth temperature sensor 63 as the target hot water storage temperature (for example, 75 ° C) The rotational speed of the hot and cold water pump 61 is controlled (# 302) so as to become), otherwise nothing is done (to # 303).
Incidentally, the main control unit 95 controls the target rotational speed of the hot water pump 61 (that is, a value proportional to the flow rate of hot water flowing through the exhaust heat recovery heat exchanger 55) under the control of # 301 to # 302. It controls according to the following [Formula 2].

Target rotation speed = current rotation speed + B (hot water temperature which has flowed through the exhaust heat recovery heat exchanger-hot water storage target temperature) ... [Formula 2]
Here, B is a positive constant.

If the cooling water temperature is “low temperature” or “medium temperature”, the main body side control unit 95 stops the hot water pump 61 (# 304), and otherwise does nothing (to # 301).
The control of # 301 to # 304 described above corresponds to the hot water flow control.

  Incidentally, in the first embodiment, the flowing state of the cooling water C and the hot water W when only the above-described hot water storage operation is being performed is the state shown in FIG. 3 and only the above heating operation is performed. The flowing state of the cooling water C and the heat medium H in the case where the cooling water C and the heating medium H are in the state shown in FIG. 4 and both the storage water operation and the heating operation described above are performed. The flow state of the medium H is the state shown in FIG.

Second Embodiment
In the cogeneration system 100 according to the second embodiment, the configuration related to the cooling water circulation path 42 and the heating circulation path 34 related to the heating heat exchanger 56 in the cogeneration system 100 of the first embodiment. In the heating operation, the cooling medium distribution flow control is performed instead of the heat medium distribution flow control.
The following description will be made with emphasis on the configuration and control relating to the difference, and the other configurations will be assigned the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

In the heating circulation path 34 according to the second embodiment, the main body side heat medium flow path 104 for guiding the entire amount of the heat medium H flowing through the return header 32 to the cogeneration system main body 40 as in the first embodiment. Although the heat medium bypass passage 104 b and the heat medium three-way adjustment valve 113 are not provided in the main body side heat medium flow path 104 as in the first embodiment.
That is, in the second embodiment, the entire amount of the heat medium H flowing through the main body side heat medium passage 104 flows through the heating heat exchanger 56. The main body side heat medium flow path 104 is provided with a sixteenth temperature sensor 102 b that detects the temperature of the heat medium H before the heat source device 10 flows after the heating heat exchanger 56 flows.
Incidentally, also in the cogeneration system 100 according to the second embodiment, the heat medium pump for pressure-feeding the heat medium H is not provided in the housing of the cogeneration system main body 40, and the heat provided in the heat source machine 10 The heat medium is circulated at the discharge pressure of the medium pump 19.

In the cooling water circulation path 42, a cooling water pump 46 for feeding the cooling water C along the circulating direction of the cooling water C, a solenoid valve 47 capable of interrupting the flow of the cooling water, and a cooling water jacket in the cogeneration unit 41 (shown Omitted), the sixth temperature sensor 50 for detecting the temperature of the cooling water C discharged from the cooling water jacket, the exhaust heat recovery heat exchanger 55, and the buffer tank 51 for temporarily storing the cooling water C in the order described It is arranged by.
Furthermore, a cooling water bypass passage 36 (cooling water) that flows through part or all of the cooling water C before flowing through the exhaust heat recovery heat exchanger 55 after flowing through the cogeneration unit 41 in the cooling water circulation path 42 (cooling water An example of the bypass path is provided.
Furthermore, in the cooling water bypass passage 36, the cooling water flowing through the cooling water bypass passage 36, the flow of the heating radiator 33 after the flow (after the flow of the return header 32) and the flow of the heat source unit 10 before the flow. The heating heat exchanger 56 for heat exchange with the heat medium H of the main body side heat medium flow path 104 is provided, and at the connection site with the cooling water circulation path 42 at the downstream side in the flow direction of the cooling water C The cooling water three-way adjusting valve 35 is provided to adjust the ratio between the flow rate of the cooling water C flowing through the cooling water bypass passage 36 and the flow rate of the cooling water C flowing through the cooling water circulation passage 42 side. . As in the first embodiment, the buffer tank 51 is provided with a fifth temperature sensor 49 for detecting the temperature of the cooling water C temporarily stored.

  Furthermore, in the cogeneration system 100 of the second embodiment, the control related to the heating operation is different from that of the cogeneration system 100 of the first embodiment, and the other controls are the same. Hereinafter, based on the control flow of FIG. 13, the control which concerns on heating operation is demonstrated.

(Control related to heating operation)
During the operation of the cogeneration unit 41, the following determination control of # 401 to # 404 is repeatedly executed. When the heating operation is turned on by the remote control 27 and the cooling water temperature is set to "medium temperature" or "high temperature" while the cooling water circulation control is being executed (# 401 Control the opening degree of the cooling water three-way adjustment valve 35 so that the heat medium temperature (the temperature detected by the sixteenth temperature sensor 102b) flowing through the heating heat exchanger 56 becomes the set heating heat medium temperature (# 402 ) And if not, do nothing (to # 403). Incidentally, in the control of # 401 and # 402, the main body side control section 95 controls the opening degree (target position) of the cooling water three-way adjusting valve 35 on the cooling water bypass passage 36 side according to the following [Equation 3]. Ru.

  Target position = present position + C (set heating heat medium temperature-heat medium temperature flowing through the heat exchanger for heating) ..... [Equation 3]

  Here, C is a positive constant. In the said [Formula 3], the opening degree by the side of the cooling water bypass passage 36 of the cooling water three-way adjustment valve 35 is controlled to an opening side, so that a target position is large.

  When the heating operation is turned off by the remote control 27 or the cooling water temperature is “low temperature” (# 403), the main body side control unit 95 side of the heating heat exchanger 56 side of the cooling water three-way adjustment valve 35 The opening degree of the (cooling water bypass passage 36 side) is controlled to be fully closed (# 404), otherwise, nothing is performed (to # 401).

The control of # 401 to # 404 described above corresponds to cooling water flow rate distribution control.
Incidentally, in the second embodiment, the flowing state of the cooling water C and the hot water W when only the above-described hot water storage operation is being performed is the state shown in FIG. 10, and only the above heating operation is performed. The flowing state of the cooling water C and the heat medium H in the case where the cooling water C and the heating medium H are in the state shown in FIG. 11, and both the storage water operation and the heating operation described above are performed. The flow state of the medium H is shown in FIG.

Another Embodiment
(1) In the embodiment described above, the coolant temperature determination is performed based on the temperature detected by the fifth temperature sensor 49 provided in the buffer tank 51 in the coolant temperature determination.
However, in the cooling water temperature determination, cooling is performed based on the detected temperature of the eighth temperature sensor 54 that detects the temperature of the cooling water C before flowing through the heat / cogeneration unit 41 after flowing through the exhaust heat recovery heat exchanger 55 The water temperature determination may be performed.

(2) In the control of # 203 and # 204 according to the heating operation of the first embodiment, when the heating operation is OFF, the heating heat exchanger for the heat medium three-way adjusting valve 113 to reduce the heat radiation loss Although the opening on the 56 side is controlled to be fully closed, it may not be separately controlled to be fully closed.
Similarly, in # 403 and # 404 of the control related to the heating operation of the second embodiment, when the heating operation is OFF, the heating heat exchanger for the cooling water three-way adjustment valve 35 to reduce the heat radiation loss. Although the opening on the 56 side is controlled to be fully closed, it may not be separately controlled to be fully closed.

  The configurations disclosed in the above embodiment (including the other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in the other embodiments as long as no contradiction arises. The embodiment disclosed in the present specification is an exemplification, and the embodiment of the present invention is not limited thereto, and can be appropriately modified without departing from the object of the present invention.

  The cogeneration system of the present invention can be effectively used as a cogeneration system capable of executing a hot water storage operation with a simple control and a simple configuration that does not need to be switched according to the presence or absence of heating operation and the presence or absence of the flow rate of the heat medium. It is.

10: heat source machine 33: heating radiator 34: heating circulation path 36: cooling water bypass path 41: cogeneration unit 42: cooling water circulation path 55: exhaust heat recovery heat exchanger 56: heating heat exchanger 90: hot water storage tank 90 95: Body side control unit 100: Cogeneration system 104: Body side heat medium flow path 104a: Case inside body side heat medium flow path 104b: Heat medium bypass passage C: Cooling water H: Heat medium

Claims (4)

A heat source machine capable of performing a heating operation of heating a heat medium to a preset heating heat medium temperature set in advance and guiding the heated heat medium to a heating radiator through a heating medium circulation path for heating;
Cogeneration unit that generates electricity and heat,
A cooling water circulation path for circulating cooling water for recovering heat generated by the cogeneration unit;
Hot water circulation path which circulates hot water stored in hot water storage tank,
An exhaust heat recovery heat exchanger that exchanges heat between the cooling water flowing through the cooling water circulation path and the hot water flowing through the hot water circulation path;
A cogeneration system comprising a control unit that controls operation,
A heat medium bypass passage which flows through a part or all of the heat medium of the heat medium circulation passage after the heating radiator and before the heat source machine;
Heat exchange for heating which exchanges heat between the cooling water in the cooling water circulation path after flowing through the cogeneration unit and before flowing through the exhaust heat recovery heat exchanger and the heat medium flowing through the heat medium bypass path Equipped with
When the cooling water is in an intermediate temperature or high temperature state while the control unit is performing cooling water circulation control for circulating the cooling water in the cooling water circulation path, the heat medium in the heat medium circulation path and the heat medium bypass The heat medium distribution flow rate control for controlling the heat medium distribution flow rate to the heat medium bypass passage is performed such that the heat medium junction temperature on the downstream side where the heat mediums of the paths merge is equal to the set heating heat medium temperature. When the cooling water is in a high temperature state, the flow rate control of hot and cold water flowing through the exhaust heat recovery heat exchanger so that the hot water flowing through the exhaust heat recovery heat exchanger becomes a target temperature for storing hot water Cogeneration system to carry out.   The control unit controls the heat medium distribution flow rate to the heat medium bypass passage to zero when the cooling water is in a low temperature state with the cooling water circulation control in which the cooling water is circulated in the cooling water circulation path. The cogeneration system according to claim 1, wherein the heat medium distribution flow control is performed. A heat source machine capable of performing a heating operation of heating a heat medium to a preset heating heat medium temperature set in advance and guiding the heated heat medium to a heating radiator through a heating medium circulation path for heating;
Cogeneration unit that generates electricity and heat,
A cooling water circulation path for circulating cooling water for recovering heat generated by the cogeneration unit;
Hot water circulation path which circulates hot water stored in hot water storage tank,
An exhaust heat recovery heat exchanger that exchanges heat between the cooling water flowing through the cooling water circulation path and the hot water flowing through the hot water circulation path;
A cogeneration system comprising a control unit that controls operation,
A cooling water bypass passage that flows through all or part of the cooling water of the cooling water circulation passage after flowing through the cogeneration unit and before flowing through the exhaust heat recovery heat exchanger;
A heating heat exchanger is provided which exchanges heat between the heat medium in the heat medium circulation path after the flow of the heating radiator and before the heat source machine and the cooling water flowing through the cooling water bypass path. ,
In the state where the control unit is performing a cooling water circulation control that circulates the cooling water in the cooling water circulation path, when the cooling water is in an intermediate temperature or high temperature state, the heat medium flowing through the heating heat exchanger The cooling water distribution flow rate control for controlling the cooling water distribution flow rate to the cooling water bypass passage is executed so that the temperature becomes the set heating heat medium temperature, and the exhaust heat recovery is performed when the cooling water is in a high temperature state A cogeneration system that executes hot and cold water flow control for controlling the flow rate of hot and cold water flowing through the exhaust heat recovery heat exchanger such that the hot and cold water flowing through the heat exchanger reaches a target hot water storage temperature.   The control unit controls the cooling water distribution flow rate to the cooling water bypass passage to zero when the cooling water is in a low temperature state while performing the cooling water circulation control of circulating the cooling water in the cooling water circulation path. The cogeneration system according to claim 3, wherein the cooling water distribution flow control is performed.

Images