JP2017187190A - Electrothermal cogeneration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrothermal cogeneration system capable of coping with surplus power without providing a large capacity of an electric heater, and capable of properly operating according an original objective.SOLUTION: A controller C that an electrothermal cogeneration system has is configured to, when it is determined that an excessive power condition that output power of an electrothermal cogeneration device 10 becomes excessive is satisfied, among a plurality of apparatuses operating with power consumption, which a waste heat recover device 20 has, perform out-of-target operation for operating apparatuses to be stopped; and when it is determined that the excessive power condition is not satisfied, avoid performing the out-of-target operation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a combined heat and power system including a combined heat and power device that generates heat and electricity, an exhaust heat recovery device, and a control device.

  Patent Literature 1 describes a combined heat and power system including a combined heat and power device that can perform switching between a linked operation linked to a power system and a self-sustained operation not linked to a power system. This combined heat and power system is configured to consume the output power of the combined heat and power unit with a self-supporting load connected to a power outlet for self-sustained operation during self-sustaining operation, and to consume surplus power that cannot be consumed with the self-supporting load. With internal load. That is, such an internal load is used as an electric heater for surplus power consumption.

In addition, when reverse power flow from the combined heat and power unit to the power system is prohibited, surplus power is consumed when surplus is generated in the output power of the combined heat and power unit even during grid operation. Must be consumed with an electric heater.
In this way, when reverse power flow from the combined heat and power device to the power system is prohibited, the surplus of the combined heat and power device, regardless of whether the combined heat and power device is operating in a grid or independent operation. A large-capacity electric heater is required to consume power.

In addition, a system that consumes surplus power by a method different from the consumption by the electric heater has been proposed.
For example, Patent Document 2 describes a combined heat and power system including a combined heat and power device (fuel cell power generation system 20) that generates heat and electricity together, and an exhaust heat recovery device (heat utilization system 8). . In this combined heat and power system, when the power consumption of the electric load that is supplied with the output power from the combined heat and power device is smaller than the output power that is supplied from the combined heat and power device to the electric power during the self-sustaining operation of the combined heat and power device, It is described that the power consumption of the auxiliary machine is increased by using the output power from the co-feeding device. That is, in order to consume the surplus power, the power consumption of the auxiliary machine already in operation is further increased. As auxiliary equipment, an exhaust heat recovery water pump, an oxidant gas blower, a cooling water pump, a reforming water pump, and the like are described.

JP2015-156769A JP 2014-192006 A (paragraph 0029 and the like)

In the case of the system described in Patent Document 1, when reverse power flow from the combined heat and power device to the power system is allowed, even if surplus occurs in the output power of the combined heat and power device, the surplus power is transferred to the power system. What is necessary is just to make it reverse flow. Therefore, an electric heater for consuming surplus power of the combined heat and power supply device is not necessary only during the grid operation. However, if surplus power is generated during the self-sustaining operation, an electric heater for consuming the surplus power is required.
Therefore, in the conventional combined heat and power system, it is necessary to provide a large-capacity electric heater at least for the treatment of surplus power during the independent operation, regardless of whether or not reverse power flow to the power system is allowed.

  Further, in the case of the system described in Patent Document 2, in order to consume surplus power, the power consumption of the auxiliary machine already in operation is further increased. In other words, auxiliary equipment such as exhaust heat recovery water pump, oxidant gas blower, cooling water pump, reforming water pump, etc. that are operated with appropriate output according to the specific purpose is forced to consume surplus power. The output is increased. As a result, the combined heat and power system may not operate according to the original purpose.

  The present invention has been made in view of the above-described problems, and the purpose thereof is to perform processing of surplus power without having a large-capacity electric heater and to operate appropriately according to the original purpose. It is in providing a combined heat and power system that can be made.

In order to achieve the above object, the characteristic configuration of the combined heat and power system according to the present invention includes a combined heat and power device that generates heat and electricity, an exhaust heat recovery device, and a control device, and the exhaust heat recovery device. Has a heat storage device capable of storing heat generated by the heat and power supply device, and heat load device for at least one of heat generated by the heat and power supply device and heat stored in the heat storage device The control device causes the exhaust heat recovery device to collect heat generated by the heat / electric supply device and store heat in the heat storage device when the heat / electric supply device is operating. , During the grid-operated operation of the combined heat and power device to the power system, power is supplied from at least one of the power system and the combined heat and power device to the power consuming device and the exhaust heat recovery device, and the combined heat and power device Independence A rolling sometimes cogeneration system for supplying power from the cogeneration device to the power consumption device and the exhaust heat recovery apparatus,
The controller is
When it is determined that the excess power condition that the output power of the combined heat and power supply device is excessive is satisfied, the exhaust heat recovery device has a device to be stopped among a plurality of devices that consume and operate power Make it run unintended,
When it is determined that the excessive power condition is not satisfied, the non-target operation is not performed.

According to the above characteristic configuration, when the control device determines that the excess power condition that the output power of the combined heat and power supply device is excessive is satisfied, the device to be stopped among the plurality of devices included in the exhaust heat recovery device By performing the unintended operation for operating the power, at least a part of the output power of the combined heat and power supply device can be consumed by the unintended operation. On the other hand, when the controller determines that the excess power condition that causes the output power of the combined heat and power supply device to be excessive is not satisfied, the output power of the combined heat and power supply device is not It can be prevented from being consumed by driving.
In this way, the control device can reduce the role of the electric heater for surplus power consumption, which has been conventionally required, by consuming at least a part of the output power of the combined heat and power supply device by non-target operation.
Moreover, what is operated by performing the non-target operation is not a device that is operating at an appropriate output according to the operation purpose of the exhaust heat recovery apparatus, but a device that should be stopped. As a result, even if this unintended operation is performed, it is ensured that the operation of the exhaust heat recovery device is continued in an appropriate state.
Therefore, it is possible to provide a combined heat and power system that can process surplus power without providing a large-capacity electric heater and can be appropriately operated according to the original purpose.

  Another characteristic configuration of the combined heat and power system according to the present invention is that the control device satisfies the excess power condition when a surplus occurs in the output power of the combined heat and power device when the non-target operation is not performed. And when the surplus power does not occur in the output power of the cogeneration apparatus when the non-target operation is not performed, the excess power condition is not satisfied.

  According to the above characteristic configuration, when there is a surplus in the output power of the cogeneration device when the non-target operation is not performed, the non-target operation is performed and the output power of the cogeneration device is consumed. As a result, surplus power in the output power of the combined heat and power supply device can be reduced.

  Still another characteristic configuration of the combined heat and power system according to the present invention is that the control device is configured such that the non-target operation is not performed in a state where the interconnection operation of the combined heat and power device is not performed. When surplus occurs in the output power, it is determined that the excess power condition is satisfied, and the non-target operation is not performed in the state where the interconnection operation of the combined heat and power device is not performed. When there is no surplus in the output power, or when the combined operation of the thermoelectric generator is being performed, it is determined that the excess power condition is not satisfied.

In a state where the combined operation of the combined heat and power device is not performed, if surplus occurs in the output power of the combined heat and power device, the surplus power must be consumed by some device.
Therefore, in this feature configuration, when the controller does not perform the interconnection operation of the combined heat and power unit and the above-mentioned operation is not performed, when the surplus occurs in the output power of the combined heat and power unit, the excessive power condition Is determined to be satisfied, and at least a part of the output power of the combined heat and power supply device is consumed by the non-target operation. As a result, surplus power that must be consumed by some device can be reduced.

  Still another characteristic configuration of the combined heat and power system according to the present invention is that the exhaust heat recovery device has one of a plurality of devices that operate by consuming electric power. A heating medium pump for adjusting the amount of flow of the heating medium in the heating medium path for circulating the medium, and the controller is configured to stop the heating medium pump at a time The non-target operation is performed by operating the heating medium pump for heating.

  According to the said characteristic structure, the surplus electric power of the output electric power of a heat-and-electric power supply apparatus can be made small by operating the heating-medium pump for heating and consuming electric power.

  Still another characteristic configuration of the combined heat and power system according to the present invention is that the exhaust heat recovery device has hot water in one of a plurality of devices that operate by consuming electric power, as a heat storage device. A bath-pumping circulation pump that adjusts the flow rate of the hot water in the bath-medium heating medium for circulating the bath, and the control device stops the bath-pickup circulation pump to stop the bath It is in the point which makes the said non-target operation | movement operate by operating the said bath recirculation circulation pump at the time which should stop the bath renewal in a memorial part.

  According to the said characteristic structure, the surplus electric power of the output electric power of a thermoelectric power supply apparatus can be made small by operating the circulation pump for bath remedy and consuming electric power.

  Still another characteristic configuration of the combined heat and power system according to the present invention is that the exhaust heat recovery device has one of a plurality of devices that operate by consuming electric power, and is configured to circulate heat by combustion heat obtained by burning fuel. A heat medium circulation pump that adjusts a flow amount of the circulation heat medium in a heat medium circulation path for circulating the circulation heat medium so as to pass through a heat source unit that heats the medium; The heat medium circulation pump is stopped and the non-target operation is performed by operating the heat medium circulation pump at a time when the circulation of the circulation heat medium should be stopped.

  According to the above characteristic configuration, surplus power in the output power of the combined heat and power supply device can be reduced by operating the heat medium circulation pump to consume power.

  Yet another characteristic configuration of the combined heat and power system according to the present invention is that the exhaust heat recovery device has, as one of a plurality of devices that operate by consuming electric power, to the outside air of heat stored in the heat storage device. A radiator for adjusting the amount of heat released from the radiator, and the controller is configured to perform the non-target operation by operating the radiator at a time when the heat radiation by the radiator should be stopped.

  According to the above characteristic configuration, surplus power in the output power of the cogeneration apparatus can be reduced by operating the radiator to consume power.

  Still another characteristic configuration of the combined heat and power system according to the present invention is a heat source device that burns fuel and generates combustion heat as one of a plurality of devices that operate by consuming electric power, included in the exhaust heat recovery device. The control device causes the non-target operation to be performed by operating the blower fan at a time when the blower fan should be stopped. In the point.

  According to the said characteristic structure, the surplus electric power of the output electric power of a thermoelectric power supply apparatus can be made small by operating a ventilation fan and consuming electric power.

  Still another characteristic configuration of the combined heat and power system according to the present invention is a freeze prevention device that prevents freezing due to generated Joule heat as one of a plurality of devices that operate by consuming electric power that the exhaust heat recovery device has. The controller has a heater and operates the non-target operation by operating the freeze prevention heater at a time when the freeze prevention heater should be stopped.

  According to the above characteristic configuration, surplus power in the output power of the cogeneration apparatus can be reduced by operating the freeze prevention heater to consume power.

It is a figure which shows the structure of a combined heat and power system. It is a figure which shows the structure of an exhaust heat recovery unit.

<First Embodiment>
A cogeneration system according to a first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration of a combined heat and power system. FIG. 2 is a diagram illustrating a configuration of the exhaust heat recovery unit. As shown in the figure, the combined heat and power system includes a power generation unit 10 (an example of the combined heat and power supply apparatus of the present invention) that generates heat and electricity together, and an exhaust heat recovery unit 20 (an example of the exhausted heat recovery apparatus of the present invention). And a control device C.

[Power generation unit]
In the present embodiment, the fuel cell unit 12 as a combined heat and power unit of the power generation unit 10 includes a plurality of cells each having a fuel electrode supplied with a fuel gas such as hydrogen and an air electrode supplied with oxygen. It has a cell stack. The fuel cell unit 12 can be configured using various types of cells such as a polymer cell and a solid oxide cell. The power generation unit 10 of the present embodiment also includes a fuel reforming unit 13 for supplying a fuel gas (hydrogen etc.) generated by steam reforming of hydrocarbons or the like to the fuel cell unit 12. Yes.

  The power generated by the fuel cell unit 12 is output to either the interconnected power line 4 or the independent power line 5 via the power conversion unit 11 having an inverter or having a converter, an inverter, and the like. In the present embodiment, the power output from the fuel cell unit 12 is described as generated power, and the power output from the power generation unit 10 is described as output power. It can be said that the state in which the output power is supplied from the power conversion unit 11 to the interconnection power line 4 is a state in which the power generation unit 10 performs the interconnection operation. On the other hand, it can be said that the state in which output power is supplied from the power conversion unit 11 to the independent power line 5 is a state in which the power generation unit 10 is performing an independent operation. The interconnection power line 4 is connected to an AC line 2 connected to the power system 1, and the AC line 2 is connected to a changeover switch 6. The independent power line 5 is connected to the changeover switch 6 separately from the AC line 2. The changeover switch 6 operates so as to switch the power supply source for the exhaust heat recovery unit 20 to either the power supplied via the AC line 2 or the power supplied via the independent power line 5. The operation of the changeover switch 6 may be controlled by the control device C, or automatically switched according to a change in the power supply destination from the power generation unit 10 (that is, whether or not power is supplied via the independent power line 5). The switch 6 may be configured to operate. The power generation unit 10 includes a cooling fan 15 as a temperature adjustment unit that adjusts the temperature of the power conversion unit 11.

  When the control device C enters a normal state in which power supply from the power system 1 to the AC line 2 is normally performed, the control device C performs an interconnection operation for supplying the output power of the power generation unit 10 to the AC line 2. 2 is configured to perform a self-sustaining operation in which the output power of the power generation unit 10 is supplied to the self-sustained power line 5 that is electrically disconnected from the power system 1 when an abnormal state in which power supply to the power source 2 is not normally performed. In the present embodiment, the control device C is in a normal state in which power supply from the power system 1 to the AC line 2 is normally performed, or power supply from the power system 1 to the AC line 2 is normally performed. For example, it is determined with reference to the voltage of the AC line 2 detected by the instrument transformer VT. That is, if the detected voltage value is equal to or higher than the set lower limit voltage, the control device C determines that the power supply from the power system 1 to the AC line 2 is normally performed, and the detected voltage If the value is less than the set lower limit voltage, it is determined that the power supply from the power system 1 to the AC line 2 is not in an abnormal state.

  In this way, the control device C can at least connect the power system 1 and the power generation unit 10 to the power consumption device (general power load device 3) and the exhaust heat recovery unit 20 when the power generation unit 10 is connected to the power system 1. Electric power is supplied from either one, and when the power generation unit 10 operates independently, power is supplied from the power generation unit 10 to the power consumption device (self-supporting load device 9) and the exhaust heat recovery unit 20.

  Note that, during the self-sustaining operation in which the output power of the power generation unit 10 is supplied to the self-sustained power line 5, the idling operation of the power generation unit 10 as one form of the self-sustaining operation may be performed. Specifically, in a state where the output power of the power generation unit 10 is supplied to the independent power line 5, the control device C and the power consumption device (self-supporting load device 9) and exhaust heat measured by the current transformer CT <b> 2 are used. When the sum of the power consumption of the recovery unit 20 becomes larger than the output power of the power generation unit 10, the idling operation is performed such that the switch 16 is temporarily opened and the power supply to the self-supporting load device 9 is temporarily stopped. May be performed.

[Exhaust heat recovery unit]
The exhaust heat recovery unit 20 has a hot water storage tank (heat storage device) 21 that can store the heat generated by the power generation unit 10, and the heat generated in the power generation unit 10 and the heat stored in the hot water storage tank 21. At least one of them is supplied to a thermal load device 24 described later. Specifically, when the control device C is operating the fuel cell unit 12 of the power generation unit 10, the heat recovery unit 20 recovers heat generated in the power generation unit 10 and stores heat in the hot water storage tank 21. And do. Therefore, in the exhaust heat recovery unit 20, in order to cool the cell stack of the fuel cell unit 12, the exhaust heat recovery unit 20 exhausts both during the interconnection operation of the power generation unit 10 and during the independent operation. It is necessary to perform an operation for recovering heat, and as a result, electric power is consumed. Power is supplied to the exhaust heat recovery unit 20 through an internal power line 17 connected to the changeover switch 6.

  In the system shown in FIG. 1, a general power load device 3 and a self-supporting load device 9 are described. The general power load device 3 is electrically connected to the AC line 2 connected to the power system 1. Therefore, the general power load device 3 can receive power supply in a normal state where power supply from the power system 1 to the AC line 2 is normally performed, but power supply from the power system 1 to the AC line 2 is possible. The power supply cannot be received in an abnormal state where the operation is not normally performed. Therefore, the general power load device 3 referred to in the present embodiment is a device (for example, a part of lighting devices) that is unlikely to receive power supply in an abnormal state.

  On the other hand, as will be described later, the self-supporting load device 9 can receive power supply from the power generation unit 10 in an abnormal state where power supply from the power system 1 to the AC line 2 is not normally performed. The electric power is supplied to the self-supporting load device 9 when electric power is supplied to the electric outlet 7 via the electric power line 5 and the electric plug 8 is connected to the electric outlet 7. . The self-supporting load device 9 is a highly important device that the user wants to use even in an abnormal state where the power supply from the power system 1 to the AC line 2 is not normally performed (for example, some lighting devices, refrigerators, etc.) ).

  The power consumption of the surplus power consumption heater 22 included in the exhaust heat recovery unit 20 is controlled by the control device C. Specifically, when surplus is generated in the output power of the power generation unit 10, the control device C consumes the surplus by the surplus power consumption heater 22 and exhausts the heat generated by the surplus power consumption heater 22. It is transmitted to the hot water flowing through the heat recovery path L 1 and stored in the hot water storage tank 21. For example, the control device C adjusts the power consumption of the surplus power consumption heater 22 so that the received power from the power system 1 that can be derived based on the detection result of the current transformer CT1 is zero or more. By performing such control, it is possible to prevent reverse power flow from the power generation unit 10 to the power system 1.

  Next, a specific example of the configuration of the exhaust heat recovery unit 20 will be described with reference to FIG.

[Exhaust heat recovery path L1]
Between the hot water storage tank 21 and the power generation unit 10, an exhaust heat recovery path L1 through which hot water circulates is provided. In the exhaust heat recovery path L1, for example, a relatively low temperature hot water stored in the hot water storage tank 21 flows into the power generation unit 10 and is heated by heat discharged from the power generation unit 10, and the heated relatively high temperature is heated. A heat storage cycle in which hot water returns to the hot water storage tank 21 is established. Further, a surplus power consumption heater 22 is provided in the middle of the exhaust heat recovery path L <b> 1 from the power generation unit 10 to the hot water storage tank 21. As a result, the hot water circulating in the exhaust heat recovery path L1 is configured so that the heat generated by the surplus power consumption heater 22 can also be recovered in the hot water storage tank 21. As described above, the heat generated in the power generation unit 10 and the heat generated in the surplus power consumption heater 22 are stored in the hot water storage tank 21.

  In addition, a radiator 38 for heat dissipation is provided in the middle of the exhaust heat recovery path L1 from the hot water storage tank 21 toward the power generation unit 10. The radiator 38 adjusts the heat radiation amount per unit time of the heat stored in the hot water storage tank 21 to the outside air. As a result, hot water can be supplied from the hot water storage tank 21 to the power generation unit 10 after the temperature of the hot water is lowered by the radiator 38. The radiator 38 functions as one of a plurality of devices that operate by consuming power supplied from at least one of the power system 1 and the power generation unit 10 of the exhaust heat recovery unit 20.

[Heat medium circulation path L6]
Hot water extracted from the upper part of the hot water storage tank 21 via the heat medium extraction path L7 can be supplied to the heat medium circulation path L6 via the three-way valve V3. The heat medium circulation path L6 includes a first heat medium circulation path L6a through which hot and cold water circulates through the bath-measuring heat exchanger 31, and a second heat medium circulation through which hot water circulates through the heating heat exchanger 30. The path L6b and the common portion L6c of the first heat medium circulation path L6a and the second heat medium circulation path L6b are configured. A three-way valve V4 is provided at a branch point from the common portion L6c of the heat medium circulation path L6 to the first heat medium circulation path L6a and the second heat medium circulation path L6b. A common part L6c of the heat medium circulation path L6 is provided with a heat medium circulation pump P1 for circulating hot water in the heat medium circulation path L6 and a heat source device 40 for heating the hot water. The heat medium circulation pump P1 is provided in the heat medium circulation path L6 for circulating the circulation heat medium so as to pass through the heat source unit 40 that heats the circulation heat medium (hot water) by the combustion heat obtained by burning the fuel. The flow rate of the circulating heat medium per unit time is adjusted. Therefore, high-temperature hot water after being heated by the heat source device 40 can be supplied to the first heat medium circuit L6a and the second heat medium circuit L6b. In the present embodiment, a gas as fuel is supplied to the combustor 34 of the heat source device 40 and is mixed with the air supplied by the blower fan F and burned. And the hot water flowing through the heat medium circulation path L6 is heated by the combustion heat. In this manner, the blower fan F adjusts the supply amount of air used for fuel combustion per unit time in the heat source unit 40 that generates combustion heat by burning the fuel.

  Here, the heat medium circulation pump P1 functions as one of a plurality of devices that operate by consuming electric power supplied from at least one of the power system 1 and the power generation unit 10 of the exhaust heat recovery unit 20. The blower fan F also functions as one of a plurality of devices that operate by consuming electric power supplied from at least one of the power system 1 and the power generation unit 10 of the exhaust heat recovery unit 20.

[Water supply channel L2, Hot water supply channel L3]
The water supply channel L2 is a water channel for replenishing the hot water storage tank 21 with water. The hot water supply channel L3 is a water channel for supplying heat (hot water) to the hot water supply unit 37 that is one of the heat load devices 24. This hot water supply path L3 branches off from the middle of the heat medium circulation path L6. Specifically, the hot water supply path L3 is branched from the middle of the heat medium circulation path L6, which is downstream of the heat source device 40 and upstream of the three-way valve V4. Therefore, hot water after heating by the heat source device 40 can be supplied to the hot water supply passage L3. Further, a hot water proportional valve V1 is provided in the middle of the hot water supply passage L3, and the hot water supply passage L3 is located downstream of the location where the hot water proportional valve V1 is provided. Since it is connected via V2, the flow rate of the hot water flowing through the hot water supply channel L3 and the flow rate of the cold water flowing into the hot water supply channel L3 from the water supply channel L2 can be adjusted and mixed. As a result, the temperature of hot water supplied to the hot water supply unit 37 can be adjusted by adjusting the opening degree of the hot water proportional valve V1 and the cold water proportional valve V2.

[Heating heat medium path L5]
The heating heat medium path L <b> 5 is a heat medium path for supplying heat to the heating device 33 that is one of the heat load devices 24. Specifically, a heating heat medium path L5 is provided so that the heat medium can be circulated between the heating heat exchanger 30 and the heating device 33. A heating medium pump P2 for circulating the heating medium in the heating medium path L5 is provided in the middle of the heating medium path L5. That is, the heating heat medium pump P2 adjusts the flow rate of the heat medium per unit time in the heating heat medium path L5 for circulating the heat medium to the heating device 33 as the heat load device 24. As described above, the heating medium flowing through the heating heat medium path L5 is heated to the heating equipment 33 after the heat is exchanged with the high-temperature hot water flowing through the second heating medium circulation path L6b in the heating heat exchanger 30 and then heated. By flowing in, heat consumption in the heating device 33 is possible.

  In this example, the heat load device 24 that consumes at least one of the heat generated in the power generation unit 10 and the heat stored in the hot water storage tank 21 is the heating device 33 described above. The heating medium pump P2 functions as one of a plurality of devices that operate by consuming electric power supplied from at least one of the power system 1 and the power generation unit 10 of the exhaust heat recovery unit 20.

[Heat bath L4 for bath memorial]
The bath chasing heat medium path L4 is a heat medium path for supplying heat to the bath chasing part 36 which is one of the heat load devices 24. More specifically, a bath chasing heat medium path L4 is provided so that hot water can be circulated between the bath chasing heat exchanger 31 and the bathtub 35. A bath remedy circulation pump P3 for circulating hot water in the bath remedy heat medium passage L4 is provided in the middle of the bath remedy heat medium passage L4. The bath remedy circulation pump P3 adjusts the flow rate per unit time of hot water in the bath remedy heat medium path L4 for circulating hot water in the bath remedy section 36. That is, the hot water stored in the bathtub 35 and the hot water existing in the bath heating heat medium path L4 are hot hot water flowing through the first heat medium circulation path L6a in the bath heating heat exchanger 31. The temperature of the hot water stored in the bathtub 35 can be raised (that is, the bath can be memorized) by returning to the bathtub 35 after the temperature is exchanged with the heat.

  Here, the bath pump circulation pump P3 functions as one of a plurality of devices that operate by consuming electric power supplied from at least one of the power system 1 and the power generation unit 10 of the exhaust heat recovery unit 20. .

  Furthermore, in this embodiment, it has the freeze prevention heater 32 for using the heat | fever generated by consuming the electric power supplied from at least one of the electric power grid | system 1 and the electric power generation unit 10. FIG. The freezing prevention heater 32 prevents freezing due to the generated Joule heat. In the example shown in FIG. 2, the freeze prevention heater 32 includes the exhaust heat recovery path L1 and the exhaust heat recovery path L1 in order to prevent freezing of water (hot water) flowing through the exhaust heat recovery path L1, the water supply path L2, and the hot water supply path L3. A part of the water supply channel L2 and the hot water supply channel L3 is provided in a state where it can be heated. Specifically, the heat recovery path L1 between the hot water storage tank 21 and the power generation unit 10, the water supply path L2 leading to the chilled water proportional valve V2, and the hot water supply path L3 downstream from the hot water proportional valve V1 are frozen. A preventive heater 32 is provided.

  Here, the freeze prevention heater 32 functions as one of a plurality of devices that operate by consuming electric power supplied from at least one of the power system 1 and the power generation unit 10 of the exhaust heat recovery unit 20.

[Non-target driving]
The non-target operation described in the present embodiment includes a plurality of devices (heat medium circulation pump P1, heating heat medium pump P2, heating bath circulation pump P3) that operate by consuming electric power, which the exhaust heat recovery unit 20 has. Among the freeze prevention heater 32, the radiator 38, and the blower fan F), the device at the time to be stopped is operated. By performing this non-purpose operation, the power consumption of the exhaust heat recovery unit 20 can be increased. Note that it is possible to appropriately set how much the control device C increases the power consumption of the exhaust heat recovery unit 20 by the non-target operation. Further, the control device C includes two or more of a plurality of devices (heat medium circulation pump P1, heating heat medium pump P2, bath recirculation pump P3, freeze prevention heater 32, radiator 38, blower fan F). The non-target operation of the device may be performed in parallel. In addition, when surplus is still generated in the output power of the power generation unit 10 when the non-target operation is performed, the control device C may consume the surplus power with the surplus power consumption heater 22.

  For example, if it is not necessary to circulate hot water in the heat medium circulation path L6, the control device C determines that the heat medium circulation pump P1 should be stopped when the heat medium circulation pump P1 is used. And the control apparatus C can perform a non-target driving | operation by operating the heat-medium circulation pump P1 at the time which should stop the heat-medium circulation pump P1 and should stop the circulation of hot water.

  If the control device C is the heating medium pump P2, the operation of the heating device 33 is stopped, and when it is not necessary to circulate the heating medium in the heating medium path L5, the heating medium pump P2 is turned on. Judge that it is time to stop. And the control apparatus C can perform a non-target operation | movement by operating the heating medium pump P2 at the time which should stop the heating medium pump P2.

  If the control device C is a bath remedy circulation pump P3, when bath remedy is not instructed and it is not necessary to circulate hot water in the bath remedy heat medium path L4, the bath remedy circulation pump It is determined that P3 should be stopped. Then, the control device C stops the bath remedy circulation pump P3 and operates the bath remedy circulation pump P3 at a time when the bath remedy unit 36 should stop the bath remedy. Can be executed.

  In the case of the freeze prevention heater 32, for example, the control device C determines that it is time to stop the freeze prevention heater 32 when the outside air temperature is equal to or higher than the set temperature and it is not necessary to perform the freeze prevention. And the control apparatus C can perform a non-target operation | movement by operating the freezing prevention heater 32 at the time which should stop the freezing prevention heater 32. FIG.

  If the control device C is a radiator 38, the temperature of the hot water supplied from the hot water storage tank 21 to the power generation unit 10 is not more than a predetermined temperature, and it is not necessary to perform heat radiation by the radiator 38. Judge. And the control apparatus C can perform a non-target operation | movement by operating the radiator 38 at the time which should stop the heat radiation by the radiator 38. FIG.

  If it is the ventilation fan F, the control apparatus C will judge that it is time to stop the ventilation fan F, when it is not necessary to perform the combustion of the fuel with the heat-source equipment 40. And the control apparatus C can perform a non-target driving | operation by operating the ventilation fan F at the time which should stop the ventilation fan F. FIG.

[Excessive power condition]
In the present embodiment, the power excess condition is that a surplus occurs in the output power of the power generation unit 10 when the non-target operation is not performed. That is, the control device C determines that the excess power condition is satisfied when surplus occurs in the output power of the power generation unit 10 when the non-target operation is not performed, and when the non-target operation is not performed. When there is no surplus in the output power of the power generation unit 10, it is determined that the power excess condition is not satisfied. Then, when it is determined that the power excess condition is satisfied, the control device C performs the non-target operation. In contrast, the control device C does not perform the non-target operation when it is determined that the excess power condition is not satisfied.

  Note that a criterion for determining that the control device C determines that surplus power is generated in the output power of the power generation unit 10 when the unintended operation is not performed can be set as appropriate. For example, in the control device C, the output power of the power generation unit 10 when the unintended operation is not performed is a power consuming device (the general power load device 3 during the connected operation, the self-supporting load device 9 during the independent operation) and the exhaust heat recovery unit. It is determined that a surplus occurs when the sum of the power consumption of 20 is larger than the sum of the power consumption of the power generation unit 10, and if the surplus does not occur when the output power of the power generation unit 10 is less than or equal to the sum of the power consumption of the power consumption device and the exhaust heat recovery unit You may judge. Alternatively, in the control device C, the output power of the power generation unit 10 when the unintended operation is not performed is larger than the sum of the power consumption of the power consuming device and the exhaust heat recovery unit 20, and the difference is a predetermined value or more. Sometimes it is determined that surplus occurs, and the output power of the power generation unit 10 is larger than the sum of the power consumption of the power consuming device and the exhaust heat recovery unit 20, but the difference is less than a predetermined value, or the power generation unit It may be determined that no surplus occurs when the output power of 10 is equal to or less than the sum of the power consumption of the power consuming apparatus and the exhaust heat recovery unit 20.

  When the power generation unit 10 generates power and outputs power, the control device C can know the output power from the power generation unit 10 based on the current and voltage output from the power conversion unit 11. Moreover, if it is at the time of interconnection operation, the control apparatus C will be based on the measurement result of the measuring instrument current transformer CT3 installed in the AC line 2, and the general power load apparatus 3 and waste heat recovery unit at the time of interconnection operation. The sum of 20 power consumptions can be known. Or if it is at the time of a self-sustained operation, the control apparatus C of the self-supporting load apparatus 9 and the waste heat recovery unit 20 at the time of a self-sustained operation will be based on the measurement result of the measuring instrument current transformer CT2 installed in the self-supporting power line 5. You can know the sum of power consumption.

  As described above, when the control device C determines that the excess power condition in which the output power of the power generation unit 10 is excessive is satisfied, the device to be stopped among the plurality of devices included in the exhaust heat recovery unit 20 By performing the unintended operation for operating the power generator, at least a part of the output power of the power generation unit 10 can be consumed by the unintended operation. On the other hand, when it is determined that the power excess condition that causes the output power of the power generation unit 10 to be excessive is not satisfied, the control device C does not perform the non-target operation, so that the output power of the power generation unit 10 is the target. It can be prevented from being consumed by outside driving. Thus, the control apparatus C can make the role of the electric heater for surplus power consumption small by consuming at least a part of the output power of the power generation unit 10 by the non-target operation. Further, what is operated by performing the unintended operation is not an apparatus that is operating at an appropriate output according to the operation purpose of the exhaust heat recovery unit 20, but an apparatus that should be stopped. As a result, it is ensured that the operation of the exhaust heat recovery unit 20 is continued in an appropriate state even when this non-target operation is performed.

Second Embodiment
The cogeneration system of the second embodiment is different from the above embodiment in the content of the power excess condition. Although the combined heat and power system of the second embodiment will be described below, description of the same configuration as that of the above embodiment will be omitted.

  In the present embodiment, reverse power flow from the power generation unit 10 to the power system 1 is allowed. Therefore, even if surplus occurs in the output power of the power generation unit 10 in a state where the power generation unit 10 is connected, the surplus power may be reversed. That is, unlike the first embodiment, the control device C has a negative received power from the power system 1 that can be derived based on the detection result of the current transformer CT1 (that is, the power to the power system 1). Even if a reverse power flow occurs), it is not necessary to consume power by the surplus power consumption heater 22.

  Therefore, the control device C determines that the excess power condition is satisfied when surplus occurs in the output power of the power generation unit 10 when the non-target operation is not performed in the state where the power generation unit 10 is not connected. To do. That is, during self-sustained operation, power cannot be reversely flowed to the power grid 1, so that the control device C can generate the surplus in the output power of the power generation unit 10 when the non-target operation is not performed. Excessive power is reduced by performing non-target operation.

  On the other hand, when there is no surplus in the output power of the power generation unit 10 when the non-target operation is not performed in the state where the power generation unit 10 is not connected, or the power generation unit 10 is connected. It is determined that the power excess condition is not satisfied when the current state is being performed. That is, the control device C may be configured not to execute the unintended operation.

<Another embodiment>
<1>
In the said embodiment, although the specific example was given and demonstrated about the structure of the cogeneration system of this invention, the structure can be changed suitably.
For example, in the above embodiment, the example in which the power generation unit 10 as the cogeneration device includes the fuel cell unit 12 has been described. However, the power generation unit 10 includes an engine and a generator driven by the engine, You may comprise using other apparatuses, such as an apparatus of the type in which the electric power output from a generator and the heat discharged | emitted from an engine are utilized.

<2>
The configurations disclosed in the above-described embodiments (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, and are disclosed in this specification. The embodiment is an exemplification, and the embodiment of the present invention is not limited to this, and can be appropriately modified without departing from the object of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for a combined heat and power supply system that can process surplus power without having a large-capacity electric heater and can be appropriately operated according to the original purpose.

1 Power system 3 General power load equipment (power consumption equipment)
9 Self-supporting load device (power consumption device)
10 Power generation unit (cogeneration unit)
20 Waste heat recovery unit (exhaust heat recovery device)
32 Freezing prevention heater (equipment)
33 Heating equipment (heat load device)
36 Bath memorial part (heat load device)
38 Radiator (equipment)
40 Heat source machine C Control device F Blower fan (equipment)
L4 Heating medium path for bath remedy L5 Heating medium path for heating L6 Heating medium circulation path P1 Heating medium circulation pump (equipment)
P2 Heating medium pump for heating (equipment)
P3 Bath pump circulation pump (equipment)

Claims (9)

A combined heat and power device that generates heat and electricity, an exhaust heat recovery device, and a control device,
The exhaust heat recovery device has a heat storage device capable of storing heat generated by the cogeneration device, and at least one of heat generated by the cogeneration device and heat stored in the heat storage device Supply one to the heat load device,
The controller is
When operating the combined heat and power supply device, in the exhaust heat recovery device, the heat generated in the combined heat and power supply device and the heat storage to the heat storage device,
At the time of interconnection operation of the cogeneration device to the power system, power is supplied from at least one of the power system and the cogeneration device to the power consuming device and the exhaust heat recovery device, and the cogeneration device is independent. A combined heat and power system that supplies power from the combined heat and power supply device to the power consumption device and the exhaust heat recovery device during operation,
The controller is
When it is determined that the excess power condition that the output power of the combined heat and power supply device is excessive is satisfied, the exhaust heat recovery device has a device to be stopped among a plurality of devices that consume and operate power Make it run unintended,
A combined heat and power system that does not perform the unintended operation when it is determined that the excess power condition is not satisfied. The controller is
When surplus occurs in the output power of the cogeneration device when the non-target operation is not performed, it is determined that the excess power condition is satisfied,
The combined heat and power system according to claim 1, wherein when there is no surplus in the output power of the combined heat and power supply device when the non-target operation is not performed, the excess power condition is determined not to be satisfied. The controller is
When surplus occurs in the output power of the combined heat and power device when the non-target operation is not performed in the state where the interconnection operation of the combined heat and power device is not performed, it is determined that the excess power condition is satisfied,
When there is no surplus in the output power of the cogeneration device when the non-target operation is not performed in the state where the cogeneration operation of the cogeneration device is not performed, or the interconnection operation of the cogeneration device The combined heat and power system according to claim 1, wherein the excess power condition is determined not to be satisfied when the power is being used. The heating in the heating heat medium path for circulating the heating heat medium to the heating equipment as the heat load device as one of a plurality of devices that operate by consuming electric power that the exhaust heat recovery device has A heating medium pump for adjusting the flow rate of the heating medium for heating,
The combined heat and power supply according to any one of claims 1 to 3, wherein the controller performs the non-target operation by operating the heating medium pump at a time when the heating medium pump should be stopped. system. As one of a plurality of devices that operate by consuming electric power that the exhaust heat recovery device has, the bath heating heat passage for circulating hot water to the bath tracking section as the heat load device It has a circulation pump for bath remedies that adjusts the flow of hot water,
The control device performs the non-target operation by operating the bath remedy circulation pump at a time to stop the bath remedy circulation pump and stop the bath remedy at the bath remedy section. The combined heat and power system according to any one of claims 1 to 4. As one of a plurality of devices that operate by consuming electric power that the exhaust heat recovery device has, the circulating heat medium passes through a heat source device that heats the circulating heat medium by combustion heat obtained by burning fuel. A heat medium circulation pump that adjusts the flow amount of the circulation heat medium in the heat medium circulation path for circulating
6. The control device according to claim 1, wherein the controller performs the non-target operation by operating the heat medium circulation pump at a time when the heat medium circulation pump is stopped and the circulation of the circulation heat medium is to be stopped. A combined heat and power system according to claim 1. As one of a plurality of devices that operate by consuming electric power, the exhaust heat recovery device has a radiator that adjusts a heat release amount of heat stored in the heat storage device to the outside air,
The combined heat and power system according to any one of claims 1 to 6, wherein the control device causes the non-target operation to be performed by operating the radiator at a time when heat dissipation by the radiator should be stopped. As one of a plurality of devices that operate by consuming electric power, the exhaust heat recovery device adjusts the supply amount of air used for fuel combustion in a heat source unit that generates combustion heat by burning fuel. Have a blower fan,
The combined heat and power system according to any one of claims 1 to 7, wherein the control device causes the non-target operation to be performed by operating the blower fan at a time when the blower fan should be stopped. As one of a plurality of devices that operate by consuming electric power, the exhaust heat recovery device has a freezing prevention heater that prevents freezing due to generated Joule heat,
The combined heat and power system according to any one of claims 1 to 8, wherein the controller performs the non-target operation by operating the freeze prevention heater at a time when the freeze prevention heater should be stopped.

Images