JP2016176425A - Steam generating type cogeneration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam generating type cogeneration system which enables: a supply thermoelectric ratio to be variably set; and a fluctuation range of the supply thermoelectric ratio to be increased.SOLUTION: A steam generating type cogeneration system comprises: a steam generator 50 which can be driven with power generated by a generator 28 as at least a portion of drive power and generates steam with heat of cooling water circulated in a cooling water circulation circuit C of an internal combustion engine as a heat source; and a control device 70 which performs control to: stop power supply to the steam generator 50 during power priority operation to enhance power generation efficiency; and drive the steam generator 50 with at least a portion of the power generated by the generator as at least a portion of the drive power thereof during steam priority operation to enhance waste heat recovery rate, a recovery rate of steam generated by a waste gas boiler and the steam generator 50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an internal combustion engine in which a mixture of fuel and combustion air is compressed and burned in a combustion chamber to generate rotational power, and a generator is driven by the rotational power, and exhaust gas discharged from the internal combustion engine The present invention relates to a steam generation type cogeneration system including an exhaust gas boiler that generates steam by using the heat of the heat as a heat source.

Conventionally, superheated steam at a temperature of 100 ° C. or higher and normal pressure (0.1 MPa) or higher can heat an object to be heated in a shorter time than the latent heat of steam. In this field, it is used for baking and drying of foods.
As an apparatus for generating such superheated steam, an internal combustion engine that drives a generator by generating rotational power by compressing and burning an air-fuel mixture of fuel and combustion air in a combustion chamber. An engine and an exhaust gas boiler that generates steam using heat of exhaust gas discharged from the internal combustion engine as a heat source are known (see Patent Document 1).
With this configuration, in the technology disclosed in Patent Document 1, electric power is generated by rotating the generator by operating the engine, and exhaust gas from the engine is guided to the exhaust gas boiler to hold the exhaust gas. It effectively functions as a so-called steam generation type cogeneration system in which high temperature steam is generated by the generated heat.

JP 2014-199209 A

In the technique disclosed in the above-mentioned Patent Document 1, there is no disclosure or suggestion about the fact that the setting conditions such as the ignition timing of the engine fluctuate. Usually, the setting conditions in such a cogeneration system are After being set, it is maintained at a fixed value.
Furthermore, in the technique disclosed in Patent Document 1, steam is limited to that generated from an exhaust gas boiler.
Since it was such a situation, in the technique disclosed in Patent Document 1, the supply thermoelectric ratio, which is the ratio between the amount of heat as the amount of steam generated and the amount of power generated in the generator, is changed. I couldn't. For this reason, for example, the power output and heat output (steam output) are constant under the conditions where the steam generation type cogeneration system is operated at the rated value, so even if the demand for power increases during the daytime in summer, etc. The output cannot follow the power demand, and the heat output could not follow the heat demand (steam demand) even when the daytime heat demand (steam demand) increases in the winter, except in summer. .
As a result, it was necessary to increase the amount of electric power purchased from the outside, or to prepare a separate steam boiler facility for driving only when heat demand (steam demand) was high, resulting in increased equipment costs There was a problem.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a steam generation type cogeneration system capable of variably setting the supply thermoelectric ratio and increasing the fluctuation range of the supply thermoelectric ratio. Is to provide

The steam generation cogeneration system to achieve the above objective is
An internal combustion engine that compresses and burns a mixture of fuel and combustion air in a combustion chamber to generate rotational power and drives a generator by the rotational power;
A steam generation type cogeneration system including an exhaust gas boiler that generates steam using heat of exhaust gas discharged from the internal combustion engine as a heat source, the characteristic configuration of which is
A steam generator configured to be able to drive the electric power generated by the generator as at least a part of the driving electric power, and to generate the steam using the heat held by the cooling water circulating in the cooling water circulation circuit of the internal combustion engine as a heat source When,
In priority operation of power to increase power generation efficiency, supply of power to the steam generator is stopped, and steam priority to increase exhaust heat recovery efficiency as recovery efficiency of steam generated in the exhaust gas boiler and the steam generator In operation, the apparatus includes a control device that performs control for causing the steam generator to work with at least a part of the power generated by the generator as at least a part of the driving power.

A steam generation cogeneration system having the above-described characteristic configuration is configured so that power generated by a generator can be driven as at least a part of drive power and circulates in a coolant circulation circuit of an internal combustion engine. Is equipped with a steam generator that generates steam using the heat held by the steam as a heat source. For example, when the heat demand (steam demand) is large, the steam generator is driven by the power generated by the generator. And the heat output (steam output) can be increased.
Furthermore, in the power priority operation for increasing the power generation efficiency, the control device stops the supply of power to the steam generator and increases the exhaust heat recovery efficiency as the recovery efficiency of the steam generated in the exhaust gas boiler and the steam generator. In the steam priority operation, since it is configured to execute control to supply at least a part of the power generated by the generator as at least a part of the driving power of the steam generator, in the power priority operation, High power generation by prohibiting the power generated by the generator from being consumed by the steam generator and increasing the net power generation (the amount of power supplied from the steam generation cogeneration system to the outside of the system) It can be operated with efficiency. Thereby, supply thermoelectric ratio can be made small.
On the other hand, in steam priority operation, the power generated by the generator is consumed by the steam generator to reduce the net amount of power generated, and the steam generated by the steam generator is generated by the exhaust gas boiler. Since the amount of heat generation is increased by adding to the generated steam, it can be operated with high exhaust heat recovery efficiency, and the generated thermoelectric ratio can be increased by converting the generated power into the amount of generated heat (the amount of generated steam). .
As described above, according to the present invention, it is possible to realize a steam generation type cogeneration system in which the supply thermoelectric ratio can be set variably and the fluctuation range of the supply thermoelectric ratio can be increased.

Further features of the steam generating cogeneration system of the present invention are as follows:
The control device lies in that a power priority ignition timing, which is an ignition timing in the power priority operation, is set to an advance side with respect to the steam priority ignition timing in the steam priority operation.

  According to the above characteristic configuration, the control device sets the power priority ignition timing, which is the ignition timing in the power priority operation, on the advance side of the steam priority ignition timing in the steam priority operation. As the combustion in the room is steep, the shaft output of the internal combustion engine can be increased to further improve the power generation efficiency, and in the steam priority operation, the combustion in the combustion chamber is made slow. The amount of exhaust heat to the exhaust gas and the amount of exhaust heat to the engine cooling water can be increased to further improve the steam generation efficiency in the steam priority operation.

Further features of the steam generating cogeneration system of the present invention are as follows:
The control device is that a power priority air-fuel ratio that is an air-fuel ratio in the power priority operation is set larger than a steam priority air-fuel ratio that is an air-fuel ratio in the steam priority operation.

  According to the above characteristic configuration, the control device sets the power priority air-fuel ratio that is the air-fuel ratio in the power priority operation to be larger than the steam priority air-fuel ratio that is the air-fuel ratio in the steam priority operation. By performing lean combustion by increasing the air-fuel ratio, it is possible to further improve the power generation efficiency, and in steam priority operation, the air-fuel ratio is decreased to increase the amount of heat generated in the combustion chamber and to exhaust gas. The amount of exhaust heat and the amount of exhaust heat to the engine coolant can be increased to further improve exhaust heat (steam) recovery efficiency.

Further features of the steam generating cogeneration system of the present invention are as follows:
The internal combustion engine
An engine body for compressing and burning an air-fuel mixture of fuel and combustion air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A cooling heat exchanger that cools the fresh air that flows through the downstream side of the compressor in the intake passage in a form of heat exchange with a cooling medium;
The control device lowers the power priority cooling degree, which is the cooling degree of fresh air in the cooling heat exchanger in the power priority operation, than the steam priority cooling degree, which is the cooling degree of fresh air in the steam priority operation. It is in the point to set.

  According to the above characteristic configuration, in the power priority operation, the control device decreases the cooling degree of the fresh air by the cooling heat exchanger, increases the temperature of the combustion air led to the combustion chamber, and peaks the combustion temperature. In the steam-priority operation, the cooling efficiency of the fresh air by the cooling heat exchanger is increased and the temperature of the combustion air led to the combustion chamber is lowered to reduce the combustion temperature. Thus, the exhaust heat amount to the exhaust gas and the exhaust heat amount to the engine cooling water can be increased to further improve the exhaust heat (steam) recovery efficiency.

Further features of the steam generating cogeneration system of the present invention are as follows:
The steam generator is configured to generate steam using heat held by the cooling water circulating in the cooling water circulation circuit of the internal combustion engine as a heat source, and compress the steam generated by the steam generator to a target steam pressure. Consisting of a vapor compressor,
In the steam priority operation, the control device is configured to operate the steam compressor using at least a part of the power generated by the generator as at least a part of the driving power.

According to the above characteristic configuration, in the steam priority operation, the control device drives at least a part of the electric power generated by the generator as at least a part of the driving power to drive the steam compressor having a relatively large power consumption. For example, when the power supply from the generator exceeds the power demand and surplus power is generated, the surplus power is appropriately consumed by the steam compressor to generate steam. In form, the supply thermoelectric ratio can be increased.
Moreover, by providing a steam compressor as a steam generator, the pressure of the steam supplied by the steam generator can be adjusted to a desired steam pressure and supplied.

Schematic configuration diagram of steam generation type cogeneration system Graph showing power output and steam output in steam priority operation and power priority operation

The steam generation type cogeneration system 100 according to the embodiment of the present invention relates to a system capable of variably setting a supplied thermoelectric ratio and increasing a fluctuation range of the supplied thermoelectric ratio.
Hereinafter, the steam generation type cogeneration system 100 according to the embodiment of the present invention will be described based on FIG. 1 and FIG.

A steam generation cogeneration system 100 shown in FIG. 1 includes a turbocharged engine, an exhaust gas boiler 60 that generates steam using heat of exhaust gas discharged from the turbocharged engine as a heat source, and a turbocharged engine. The electric power generated by the synchronous generator 28 driven by the rotational power is configured to be driven as at least a part of the driving electric power, and the heat held by the cooling water circulating through the cooling water circulation path C of the turbocharged engine is retained. A steam generation device 50 that generates steam as a heat source and a control device 70 (a concept including an ECU as an engine control device) for controlling them are configured.
The synchronous generator 28 connected to the rotating shaft of the engine body 26 is configured to be able to adjust the frequency of the generated power to the same frequency as the frequency of the power supplied from the commercial power system 72. Further, the synchronous generator 28 is provided with an automatic voltage regulator that adjusts the voltage, and the voltage of the generated power is the same as the voltage of the power supplied from the commercial power system 72 by the automatic voltage regulator. Adjusted to A distribution board 71 is provided between the synchronous generator 28 and the commercial power system 72 so that power is supplied from the distribution board 71 to a power load (not shown) in the system. It is configured.

[Configuration related to turbocharged engine]
The turbocharged engine rotates in the form in which the rotating shaft 40 is rotated by compressing and burning an air-fuel mixture M of fuel F (an example of fuel) such as natural gas and combustion air A in the combustion chamber 26a. And the exhaust gas E discharged from the combustion chamber 26a is supplied to the engine body 26 that drives the generator 28 with the rotational power and the turbine 32 provided in the exhaust passage 27 of the engine body 26, and is connected to the turbine 32. And a supercharger 30 that compresses the air-fuel mixture M as new air that is sucked into the combustion chamber 26a by the compressor 31 provided in the intake passage 20.

  Although this type of turbocharged engine is not shown in detail, an ignition plug (not shown) is used in a state where the air-fuel mixture M taken as fresh air from the intake passage 20 into the combustion chamber 26a is compressed by the piston rising. )), Sparks are ignited and burned / expanded to push down the piston and output rotational power from the rotary shaft 40, and the exhaust gas E generated by the combustion is pushed out from the combustion chamber 26a to the exhaust passage 27 and externally To be discharged.

The intake passage 20 compresses the air cleaner 21 that purifies the combustion air A, the Venturi mixer 14 that mixes the fuel F with the combustion air A at an appropriate ratio, and the air-fuel mixture M mixed in the mixer 14. A compressor 31, an intercooler 25 that cools the air-fuel mixture M (an example of a heat exchanger for cooling), and a throttle valve 24 that can adjust the intake air amount of the air-fuel mixture M to the combustion chamber 26a by adjusting the opening degree are provided from the upstream side. They are introduced in the order listed.
That is, in the intake passage 20, the air-fuel mixture M generated by mixing the fuel F and the combustion air A by the mixer 14 is compressed by the compressor 31 and then adjusted to a predetermined flow rate via the throttle valve 24. Then, it is cooled by the intercooler 25 and introduced into the combustion chamber 26 a of the engine body 26.

  Incidentally, the intercooler 25 is provided with a temperature sensor (not shown) for measuring the temperature of the air-fuel mixture M after exiting the intercooler 25 and before being introduced into the combustion chamber 26a of the engine body 26. Is configured such that the degree of cooling of the air-fuel mixture M by the intercooler 25 can be adjusted based on the temperature measured by the temperature sensor.

  In the fuel supply path 11 that guides the fuel F to the mixer 14, a differential pressure regulator V 1 that keeps the difference between the pressure of the combustion air A in the intake path 20 upstream of the mixer 14 and the pressure of the fuel F in the fuel supply path 11 constant. A fuel supply amount adjustment valve V2 for adjusting the supply amount of the fuel F supplied to the combustion chamber 26a through the mixer 14 is provided.

The engine body 26 is provided with an engine jacket 26b in its cylinder head, and the engine coolant is circulated between the engine jacket 26b and an exhaust heat recovery heat exchanger 51a provided outside the engine body 26. A cooling water circulation path C and a cooling water circulation pump P for circulating engine cooling water through the cooling water circulation path C are provided.
Although details will be described later, in the steam generation type cogeneration system 100 according to the embodiment of the present invention, the exhaust heat recovery heat exchanger 51a is connected to the engine cooling water and the feed water in the steam generation device 50 described later. It is provided for the purpose of evaporating the feed water.
For this purpose, the temperature of the engine coolant C flowing into the exhaust heat recovery heat exchanger 51a is preferably 100 ° C. or higher. From this viewpoint, the cooling water circulation pump P is also configured to function as a boosting pump that boosts the engine cooling water. In this embodiment, the temperature of the engine cooling water at the inlet of the exhaust heat recovery heat exchanger 51a is about 113 ° C., for example, and the temperature of the engine cooling water at the outlet of the exhaust heat recovery heat exchanger 61 is, for example, The number of rotations of the cooling water circulation pump P is controlled so as to be about 109 ° C. In addition, when using a coolant with a high boiling point as engine cooling water, the structure which does not raise pressure with the cooling water circulation pump P is also employable.

  The supercharger 30 supplies the exhaust gas E discharged from the combustion chamber 26 a to the turbine 32 provided in the exhaust passage 27 of the engine body 26, and is combusted by the compressor 31 provided in the intake passage 20 while being connected to the turbine 32. The turbocharger 30 is configured to compress the air-fuel mixture M sucked into the chamber 26a. That is, the supercharger 30 rotates the turbine 32 by the kinetic energy of the exhaust gas E passing through the exhaust passage 27, and rotates the compressor 31 disposed in the intake passage 20 by the rotational force of the turbine 32. So-called supercharging is performed in which the air-fuel mixture M as fresh air flowing through the intake passage 20 is supplied to the combustion chamber 26a in a compressed state.

  The rotation shaft 40 is provided with a rotation speed sensor (not shown) that measures the rotation speed of the rotation shaft 40 as the rotation speed of the engine body 26, and the control device 70 measures the rotation speed sensor. Based on the rotational speed of the engine body 26, the opening amount of the fuel supply amount adjustment valve V2 is controlled to adjust the supply amount of the fuel F to the combustion chamber 26a, so that the rotational speed of the engine body 26 is set to a desired target rotation. The rotation speed maintenance control for maintaining the speed is configured to be executable.

  The exhaust passage 27 is provided with an oxygen sensor S1 that detects the oxygen concentration of the exhaust gas E, and the control device 70 controls the throttle valve 24 based on the oxygen concentration of the exhaust gas E detected by the oxygen sensor S1. By controlling the opening degree, the mixing ratio of the combustion air A to the fuel F supplied to the mixer 14 is adjusted, and the air-fuel ratio of the air-fuel mixture M generated by the mixer 14 is maintained at a desired air-fuel ratio. The fuel ratio control is configured to be executable.

  Further, the control device 70 can execute ignition timing control for controlling the ignition timing of the air-fuel mixture M in the combustion chamber 26a to a desired timing by an ignition plug (not shown) provided in the combustion chamber 26a. It is configured.

[Exhaust gas boiler]
An exhaust gas boiler 60 is provided downstream of the turbine 32 in the exhaust passage 27.
When the explanation is added, the exhaust gas boiler 60 is provided with an exhaust gas flow chamber 27a through which the exhaust gas E after passing through the turbine 32 flows, and the exhaust gas flow chamber 27a includes a plurality of steam generation pipes 62a. Is disposed downstream of the steam generation unit 62, and a water supply preheating unit 61 is provided with a plurality of water supply heating pipes 61a. The feed water heating pipe 61 a is connected in communication with the steam generation pipe 62 a of the steam generation unit 62.
Thereby, the feed water flowing into the feed water heating pipe 61a of the feed water preheating section 61 is preheated by the exhaust heat of the exhaust gas E in the feed water preheating section 61, and then flows into the steam generation pipe 62a of the steam generation section 62, and the exhaust gas After being further heated by the exhaust heat of E and evaporated, it is discharged as the first steam St1.
Here, the flow path through which the first steam St1 discharged from the steam generating unit 62 flows includes a first steam pressure gauge S2 for measuring the pressure of the first steam St1 flowing through the flow path, and the flow path. A flow rate control valve V3 for controlling the flow rate of the first steam St1 flowing therethrough is provided. The control device 70 adjusts the opening degree of the flow control valve V3 so that the pressure of the first steam St1 is a desired pressure (for example, a pressure of about 0.7 MPa). The supply amount of the first steam St1 is determined according to the temperature of the exhaust gas E (exhaust heat amount held by the exhaust gas E).

[Steam generator]
The steam generator 50 compresses the steam generated in the steam generator 51 to a target steam pressure (for example, a pressure of about 0.7 MPa) by heating the feed water W by the exhaust heat of the engine body 26. And a vapor compressor 52 for boosting the pressure.
When the explanation is added, the steam generator 51 is provided with an exhaust heat recovery heat exchanger 51a of the cooling water circulation path C of the engine body 26, and in the exhaust heat recovery heat exchanger 51a, the engine coolant and the feed water W The engine coolant is heated by the engine exhaust heat collected by the engine jacket 26b to generate steam.
The steam compressor 52 includes a compressor 52a that compresses and boosts the steam generated by the steam generator 51, and an electric motor 52b that rotationally drives the compressor 52a. The steam generated by the steam generator 51 is compressed by the motor-driven compressor 52a, boosted to the target steam pressure, and discharged as the second steam St2. Although detailed description will be given later, the motor 52b as a drive source of the compressor 52a is generated by the turbocharged engine generator 28 in addition to using the commercial power from the commercial power system 72 as the drive power. It is comprised so that it can drive at least one part of generated electric power as drive electric power. That is, in the present embodiment, driving power is supplied from the distribution board 71 to the motor 52 b of the steam compressor 52.
Here, the flow path through which the second steam St2 discharged from the steam compressor 52 flows includes the second steam pressure gauge S3 for measuring the pressure of the second steam St2 flowing through the flow path, and the flow path. A flow rate control valve V4 for controlling the flow rate of the second steam St2 flowing therethrough is provided. The control device 70 adjusts the rotation speed of the motor-driven compressor 52a so that the pressure of the second steam St2 is set to a desired pressure (for example, a pressure of about 0.7 MPa) and the flow control valve V4. Adjust the opening. The supply amount of the second steam St2 is determined according to the exhaust heat recovery amount by the exhaust heat recovery heat exchanger 51a of the steam generator 51.
Then, both the first steam St1 supplied from the exhaust gas boiler 60 and the second steam St2 supplied from the steam generator 50 are supplied to the outside as supply steam St1 and St2.

The steam generation type cogeneration system 100 according to the embodiment of the present invention is configured to be able to variably set the supplied thermoelectric ratio, and can set a large fluctuation range of the supplied thermoelectric ratio. Hereinafter, the specific configuration will be described with reference to FIG.
In addition, as shown in FIG. 2, in facilities, such as a factory provided with the steam generation type cogeneration system 100 which concerns on the said embodiment, to the electric power load (not shown) containing the electrically driven generator 52b. As supply power, it is configured to be able to purchase power from the commercial power system 72, and as a facility for supplying steam, a steam boiler (not shown) using natural gas or the like as fuel is provided separately from the system 100, Steam is supplied from the steam boiler as steam supplied to a load (not shown).
In such a facility, it is preferable to achieve load leveling in order to reduce annual running costs of power supply and heat supply, and the steam generation type cogeneration system 100 of the present invention achieves load leveling. It is preferably used as a system for this purpose.
Here, in FIG. 2, the upper left graph is a graph showing the relationship between the power demand amount and the power supply amount during the steam priority operation, and the lower left graph is the steam demand amount during the steam priority operation. It is a graph showing the relationship with the steam supply amount, the graph on the upper right is a graph showing the relationship between the power demand and the power supply during power priority operation, and the graph on the lower right is the power priority It is a graph which shows the relationship between the steam demand amount at the time of a driving | operation, and a steam supply amount.
In FIG. 2, the relationship between demand and supply in the daytime (period indicated by t <b> 1 in FIG. 2) is mainly shown for easy explanation.
P1w in the upper left graph of FIG. 2 and P1s in the upper right graph indicate power demand covered by the amount of purchased electric power, and these values are shown in the figure for the purpose of leveling the amount of purchased electric power. The steam priority operation and the power priority operation have the same value. Further, P2w in the upper left graph in FIG. 2 and P2s in the upper right graph indicate the total amount of power demand in the daytime (period indicated by t1 in FIG. 2).
S1w in the lower left graph of FIG. 2 and S1s in the lower right graph indicate heat demand (steam demand) covered by external steam supplied from a steam boiler separately from the system 100, and these values. In order to level the amount of external steam supplied by a separate steam boiler, the steam priority operation and the power priority operation have the same value as shown in the figure. Further, S2w in the lower left graph of FIG. 2 and S2s in the lower right graph of FIG. 2 indicate the heat demand (steam demand) in the daytime (period indicated by t1 in FIG. 2).

The control device 70 recovers the exhaust heat as the recovery efficiency of the steam generated in the exhaust gas boiler 60 and the steam generator 50 (heat output to the exhaust gas of the engine body 26 and engine cooling water / amount of energy input to the engine body 26). In the steam priority operation for increasing the steam, the steam generator 50 is controlled so that at least part of the electric power generated by the generator 28 of the turbocharged engine is used as at least part of the driving power of the motor 52b of the steam generator 50. Run.
That is, in the steam priority operation, as shown in the upper left graph of FIG. 2, the generated power indicated by ΔP1 in the cogeneration generated power amount is consumed as the driving power of the motor 52b of the steam generator 50, The total amount of the purchased power amount and the net cogeneration power generation amount (the generated power amount supplied to the outside of the steam generation type cogeneration system 100) in the steam priority operation is controlled to coincide with the power demand amount P2w. .
Further, as shown in the lower left graph of FIG. 2, the amount of steam generated in the steam generator 50 is increased by the power supplied to the steam generator 50 from the generator 28 of the turbocharged engine. As the steam amount indicated by ΔS1 in the cogeneration steam amount increases, the total amount of the external steam amount and the cogeneration steam amount in the steam priority operation is controlled to coincide with the heat demand amount (steam demand amount) S2w. The
Thereby, in the said steam priority operation | movement, the supply thermoelectric ratio in the steam generation type cogeneration system 100 will be adjusted to the high side.

On the other hand, the control device 70 supplies power to the motor 52b of the steam generating device 50 in the power priority operation for increasing the power generation efficiency (the shaft output of the rotating shaft 40 of the engine body 26 / the amount of energy input to the engine body 26). The control to stop is executed.
With this control, as shown in the upper left graph of FIG. 2 and the upper right graph of FIG. 2, the cogeneration power generation amount in the power priority operation is ΔP1 more than the net cogeneration power generation amount in the steam priority operation. Increase by the amount shown.
In addition, as shown in the lower left graph of FIG. 2 and the lower right graph of FIG. 2, the cogeneration steam amount in the power priority operation is expressed by ΔS <b> 1 rather than the cogeneration steam amount in the steam priority operation. Will be reduced.

Further, the control device 70 sets the power priority ignition timing, which is the ignition timing in the power priority operation, to an advance side with respect to the steam priority ignition timing in the steam priority operation (for example, set to 1 ° to 2 ° advance side). And, the power priority air-fuel ratio that is the air-fuel ratio in the power priority operation is set larger than the steam priority air-fuel ratio that is the air-fuel ratio in the steam priority operation (for example, set to be about 0.1 to 0.2 larger), Further, the power priority cooling degree that is the cooling degree of the fresh air (mixed gas M) in the intercooler 25 in the power priority operation is set to be higher than the steam priority cooling degree that is the cooling degree of the fresh air (air mixture M) in the steam priority operation. Execute the control set to the lower side.
Here, as an example, the steam priority ignition timing is 17.5 ° BTDC, the steam priority air-fuel ratio is 1.6 in terms of excess air ratio, and the steam priority cooling degree is at the outlet of the intercooler 25. It is assumed that the degree of cooling is such that the temperature of the fresh air (mixed gas M) is about 40 ° C.
The specific values of the ignition timing, the air-fuel ratio, and the cooling degree described above are an example in the case of an SI engine using city gas (for example, 13A) as fuel, and these values are based on the type and size of the engine. It is a value that varies depending on the size.

When adjusting the air-fuel ratio, the control device 70 controls the air-fuel ratio in the form of adjusting the opening of the fuel supply amount adjustment valve V2, and when adjusting the degree of cooling of the fresh air (mixed gas M), the control device 70 is used as the refrigerant. The degree of cooling of fresh air (mixed gas M) is controlled by adjusting the flow rate of the outside air supplied to the cooler 25.
Incidentally, as described above, when the air-fuel ratio varies, the rotational speed of the engine body 26 is controlled so as to keep the shaft output of the engine body 26 substantially constant.
With this control, as shown in the upper left graph of FIG. 2 and the upper right graph of FIG. 2, the cogeneration power generation amount in the power priority operation is ΔP2 than the net cogeneration power generation amount in the steam priority operation. Increase by the amount shown.
Further, as shown in the lower left graph of FIG. 2 and the lower right graph of FIG. 2, the cogeneration steam amount in the power priority operation is lower by ΔS2 than the cogeneration steam amount in the steam priority operation. It will be.
From the above, in the power priority operation, the supply thermoelectric ratio in the steam generation type cogeneration system 100 is adjusted to the low side.

  As a result, the control device 70 increases the cogeneration power generation amount in the power priority operation by ΔP more than the net cogeneration power generation amount in the steam priority operation, and the cogeneration steam amount in the power priority operation is equal to the cogeneration amount in the steam priority operation. The fluctuation range of the supplied thermoelectric ratio is set to be large in a form in which ΔS is made smaller than the steam amount.

[Another embodiment]
(1) In the above embodiment, as another example of the steam generator 51 of the steam generator 50, the engine cooling water and the feed water W are exchanged with heat through the evaporator and the condenser of the heat pump device. And the structure which superheats the feed water W and produces | generates a vapor | steam may be employ | adopted.
With this configuration, even if the temperature of the engine coolant guided to the steam generator 51 is relatively low, the feed water W can be superheated satisfactorily.

(2) In the above embodiment, the control device 70 sets the power priority ignition timing, which is the ignition timing in the power priority operation, closer to the advance side than the steam priority ignition timing in the steam priority operation (for example, 1 ° to 2 °). The power priority air-fuel ratio that is the air-fuel ratio in the power priority operation is set larger than the steam priority air-fuel ratio that is the air-fuel ratio in the steam priority operation (for example, 0.1 to 0.2). The power priority cooling degree, which is the cooling degree of fresh air (mixed gas M) in the intercooler 25 in the power priority operation, is the cooling degree of fresh air (mixed gas M) in the steam priority operation. The example which performs the control set to the reduction | decrease side rather than a steam priority cooling degree was shown.
However, even if neither of these controls is executed, the fluctuation range of the supplied thermoelectric ratio of the steam generation type cogeneration system 100 can be set large. For this reason, the scope of the right of the present invention includes those that do not execute any one of ignition timing control, air-fuel ratio control, and fresh air (mixture M) cooling degree control.
The control of the ignition timing, the control of the air-fuel ratio, and the control of the degree of cooling of the fresh air (mixed gas M) may be performed in any one or more.

(3) The steam compressor 52 of the steam generator 50 may be an absorption heat pump, an ejector, or the like, in addition to the electric compressor 52a driven by the motor 52b.

(4) In the steam embodiment, as an example of the internal combustion engine, the configuration example including the turbocharged engine is shown. However, even if the internal combustion engine is an engine that does not include the configuration related to the supercharger 30, the present invention. Achieving a good function.
When an engine that does not include the configuration related to the supercharger 30 (including the intercooler 25) is adopted as the internal combustion engine, fresh air (mixed air M) is introduced into the intake passage 20 as an example of the fresh air temperature adjusting means. It is preferable to provide a temperature adjusting device for adjusting the temperature.
For example, the temperature adjusting device can be configured to adjust the temperature of the fresh air (mixed gas M) in such a form that heat is exchanged between hot water and fresh air (mixed gas M).

(5) In the above embodiment, an example in which a synchronous generator is provided as the generator 28 connected to the rotating shaft of the engine body 26 is shown. However, a configuration including an induction generator other than the synchronous generator is adopted. It doesn't matter.
In this case, between the induction generator and the distribution board 71, it is for system linkage that adjusts the power generated by the induction generator to the same frequency with the same voltage as the power supplied from the commercial power system 72. A configuration in which the inverter 29 is provided is employed.

(6) In the above embodiment, the feed water that has flowed into the feed water heating pipe 61 a of the feed water preheating unit 61 is preheated by the exhaust heat of the exhaust gas E in the feed water preheating unit 61. A configuration of preheating at may be adopted.

(7) In the above embodiment, the air-fuel ratio control is performed on the fuel F supplied to the mixer 14 by controlling the opening degree of the throttle valve 24 based on the oxygen concentration of the exhaust gas E detected by the oxygen sensor S1. The configuration example is shown in which the air-fuel ratio of the air-fuel mixture M generated by the mixer 14 is maintained at a desired air-fuel ratio by adjusting the mixing ratio of the combustion air A.
As the air-fuel ratio control, a pressure sensor (not shown) is provided between the throttle valve 24 and the engine body 26 in the intake passage 20, and the pressure detected by the pressure sensor is adjusted to a target mixed atmospheric pressure. Thus, a configuration in which the air-fuel ratio is adjusted to a desired value by controlling the opening of the fuel supply amount adjusting valve V2 may be adopted.
When the explanation is added, the control device 70 stores a map in which the mixed atmospheric pressure is approximately directly proportional to the power generation output (corresponding to the air-fuel ratio) at a specific engine speed. Therefore, the control device 70 controls the fuel supply amount adjustment valve V2 so that the pressure measured by the above-described pressure sensor becomes the mixed atmospheric pressure that is uniquely determined from the set air-fuel ratio by the map. Then, the air-fuel ratio control is executed in such a manner that the mixed atmospheric pressure at the outlet of the throttle valve 24 is controlled to an appropriate value.

  The configuration disclosed in the above embodiment (including another embodiment, the same shall apply hereinafter) can be applied in combination with the configuration disclosed in the other embodiment, as long as no contradiction occurs. The embodiment disclosed in this specification is an exemplification, and the embodiment of the present invention is not limited to this. The embodiment can be appropriately modified without departing from the object of the present invention.

  The steam generation type cogeneration system of the present invention can be effectively used as a steam generation type cogeneration system in which the supply thermoelectric ratio can be variably set and the fluctuation range of the supply thermoelectric ratio can be increased.

20: Intake passage 25: Intercooler 26a: Combustion chamber 27: Exhaust passage 28: Generator 30: Supercharger 31: Compressor 32: Turbine 50: Steam generator 51: Steam generator 51a: Waste heat recovery heat exchanger 52 : Steam compressor 60: Exhaust gas boiler 70: Control device 100: Steam generation type cogeneration system A: Combustion air C: Cooling water circuit E: Exhaust gas F: Fuel M: Mixture

Claims (5)

An internal combustion engine that compresses and burns a mixture of fuel and combustion air in a combustion chamber to generate rotational power and drives a generator by the rotational power;
A steam generation type cogeneration system comprising an exhaust gas boiler that generates steam using heat of exhaust gas discharged from the internal combustion engine as a heat source,
A steam generator configured to be able to drive the electric power generated by the generator as at least a part of the driving electric power, and to generate the steam using the heat held by the cooling water circulating in the cooling water circulation circuit of the internal combustion engine as a heat source When,
In priority operation of power to increase power generation efficiency, supply of power to the steam generator is stopped, and steam priority to increase exhaust heat recovery efficiency as recovery efficiency of steam generated in the exhaust gas boiler and the steam generator A steam generation type cogeneration system comprising: a control device that performs control for operating the steam generation device using at least a part of the power generated by the generator as at least a part of the driving power in operation.   2. The steam generation type cogeneration system according to claim 1, wherein the control device sets a power priority ignition timing, which is an ignition timing in the power priority operation, to a more advanced side than a steam priority ignition timing in the steam priority operation.   3. The steam generating type core according to claim 1, wherein the control device sets a power priority air-fuel ratio that is an air-fuel ratio in the power priority operation to be larger than a steam priority air-fuel ratio that is an air fuel ratio in the steam priority operation. Generation system. The internal combustion engine
An engine body for compressing and burning an air-fuel mixture of fuel and combustion air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A cooling heat exchanger that cools the fresh air that flows through the downstream side of the compressor in the intake passage in a form of heat exchange with a cooling medium;
The control device lowers the power priority cooling degree, which is the cooling degree of fresh air in the cooling heat exchanger in the power priority operation, than the steam priority cooling degree, which is the cooling degree of fresh air in the steam priority operation. The steam generation type cogeneration system according to any one of claims 1 to 3, wherein the steam generation type cogeneration system is set. The steam generator includes a steam generator that generates steam using heat stored in the coolant circulating in the coolant circulation circuit of the internal combustion engine as a heat source, and compresses the steam generated by the steam generator to a target steam pressure. A steam compressor that boosts the pressure
5. The control device according to claim 1, wherein, in the steam priority operation, the steam compressor is operated using at least a part of electric power generated by the generator as at least a part of driving electric power. Steam generation cogeneration system.

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