JP2000161139A - Cogeneration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply energy in a form of capable of increasing applications by rationally improving an arrangement for utilizing energy recycled by a cooling means for cooling an engine. SOLUTION: This system is provided with an engine 2 for driving an engine- driven generator 1 and with a cooling means C for cooling the engine 2 by supplying cooling water to the engine 2 while discharging to a stem recycling path 3 steam generated by heat generated from the engine 2. In this case, the system is provided with a power generation means D for converting the energy of the steam discharged from the cooling means C to the steam recycling path 3 into mechanical torque and an auxiliary generator 5 driven by the mechanical torque of the power generation means D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine for driving an engine-driven generator, and a method of supplying cooling water to the engine and discharging steam generated by heat generated from the engine to a steam recovery path. The present invention relates to a cogeneration system provided with cooling means for cooling the engine.

[0002]

2. Description of the Related Art In such a cogeneration system, conventionally, electric power generated by an engine driven generator has been used, and steam recovered by cooling means has been used as it is.

[0003]

However, since the cooling means must fulfill the essential function of cooling the engine, there is a limit to increasing the pressure of the steam obtained from the cooling means. 1.0Kg / cm2
Only low-pressure steam of about G can be obtained. Therefore, conventionally, low-pressure steam obtained from the cooling means is used as it is. Therefore, the low-pressure steam has a high utility value compared with high-temperature water, but has a low pressure. For example, it can be used for sterilization and heating, but when it is used as process steam at the stage of processing various products such as fiber, food, and chemical industries, the application is narrow because the pressure and temperature are not always sufficient.

[0004] The present invention has been made in view of the above circumstances, and an object thereof is to rationally improve the utilization configuration of energy recovered by cooling means for cooling an engine, and to expand applications. To provide energy in a form.

[0005]

Means for Solving the Problems [Invention according to claim 1]
The characteristic configuration according to claim 1 is characterized in that a power generation unit that converts the energy of steam discharged from the cooling unit to the steam recovery path into a mechanical rotation force, and a mechanical rotation force of the power generation unit. An auxiliary generator to be driven is provided. According to the characteristic configuration of the first aspect, the auxiliary generator is driven by the power generation means for converting the energy of the steam discharged from the cooling means to the steam recovery path into a mechanical rotational force, and the auxiliary power generation is performed. Power is output from the machine. In other words, the thermal energy of low-pressure steam whose application is narrow due to low pressure and temperature can be converted into easy-to-use electric energy, and the easy-to-use electric energy can be effectively used. Therefore, the energy recovered by the cooling means can be supplied and converted into electric energy which can be used in a wide range of applications, instead of low pressure steam which is easily restricted by pressure and temperature. .

[0006] The invention according to claim 2 is characterized in that the power generation means for converting the energy of the steam discharged from the cooling means to the steam recovery path into a mechanical torque, It is connected to the engine so as to assist its rotation. According to the characteristic configuration of the second aspect, the rotation of the engine is assisted by the power generation unit that converts the energy of the steam discharged from the cooling unit to the steam recovery path into a mechanical rotation force. As the rotation is assisted, the output of the engine increases, and the output of the engine-driven generator driven by the engine increases. In other words, the thermal energy of low-pressure steam whose application is narrow due to low pressure and temperature can be converted into easy-to-use electric energy, and the easy-to-use electric energy can be effectively used. Therefore, the energy recovered by the cooling means can be supplied and converted into electric energy which can be used in a wide range of applications, instead of low pressure steam which is easily restricted by pressure and temperature. .

According to a third aspect of the present invention, there is provided a fuel cell system according to the third aspect, further comprising an exhaust heat recovery means for recovering exhaust heat from exhaust gas discharged from the engine, and passing through the exhaust heat recovery means. A heat exchanger for heating the steam supplied to the power generating means by the exhaust gas is provided. According to the third aspect of the present invention, in the exhaust heat recovery means, the high-temperature exhaust gas discharged from the engine is used as the exhaust heat, for example, at a pressure of 8 kg / cm ²
The high-pressure steam of G is recovered, and the high-pressure steam can be used effectively. Further, the steam supplied to the power generation means is heated by the exhaust gas passing through the exhaust heat recovery means in the heat exchanger and then supplied to the power generation means, so that the supplied steam is heated in the heat exchanger. As the temperature rises, the mechanical torque of the power generation means increases, and the power output from the auxiliary generator or the engine-driven generator increases. Therefore, it was originally abandoned,
The thermal energy of the exhaust gas that has passed through the exhaust heat recovery means can also be converted to electrical energy and used effectively, so that the overall energy efficiency can be further improved and energy savings can be further promoted. . The steam obtained from the cooling means is saturated steam, and the saturated steam is superheated by a heat exchanger to be superheated steam. Then, since the superheated steam is supplied to the power generation means, the corrosion in the power generation means can be suppressed as compared with the case of driving with the saturated steam, so that the durability of the device can be improved.

The invention according to claim 4 is characterized in that the power generation means is constituted by a turbine. In other words, the turbine has a higher conversion efficiency for converting the energy of the supplied steam into mechanical rotational force than the positive displacement steam expander. The power generation efficiency is higher and the power generation output can be increased as compared with the case where the expansion device is used. Therefore, in carrying out the present invention, it is possible to provide a specific configuration preferable for maximizing the overall energy efficiency.

[0009] According to a fifth aspect of the present invention, the power generating means is constituted by a positive displacement steam expander. In other words, the positive displacement steam expander can exhibit the expected performance even when the conditions of the supplied steam (for example, the supply flow rate and the pressure) differ in a relatively wide range, and are excellent in versatility. Therefore, the number of models of the positive displacement steam expanders provided corresponding to the conditions of the supplied steam can be reduced. On the other hand, the performance of the turbine is easily affected by the condition of the supplied steam, and the range of the condition of the steam that can exhibit the expected performance is narrow. The number of turbine models to be installed increases. Therefore,
By configuring the power generating means with a positive displacement steam expander, it is possible to reduce the cost of the power generating means as compared with a case where the power generating means is configured with, for example, a turbine. Therefore, in carrying out the present invention, it is possible to provide a specific configuration preferable for minimizing the implementation cost.

The invention according to claim 6 is characterized in that a pressure reducing means for reducing the pressure on the exhaust side of the positive displacement steam expander is provided. According to the characteristic configuration of the sixth aspect, the exhaust side of the positive displacement steam expander is depressurized by the pressure reducing means, and the mechanical rotational force of the positive displacement steam expander increases, so that the auxiliary generator or the engine driven type is used. The power output from the generator increases. Although electric power for driving the pressure reducing means is required, the electric power for driving the pressure reducing means is less effective than the increase in the power generation output by reducing the pressure on the exhaust side of the positive displacement steam expander. Power generation output increases. Therefore, the power generation efficiency can be improved, and the total energy efficiency can be further improved.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of the present invention will be described below with reference to FIG. As shown in FIG. 1, the cogeneration system includes an engine-driven generator 1, a gas engine 2 that drives the engine-driven generator 1, and supplies cooling water to the gas engine 2, and supplies the cooling water. Cooling that cools the gas engine 2 while discharging steam (hereinafter, sometimes referred to as low-pressure steam) generated by boiling by heat generated from the gas engine 2 to the upstream-side low-pressure steam path 3 as a steam recovery path. Means C and exhaust heat configured to discharge steam (hereinafter, sometimes referred to as high-pressure steam) generated by heating supplied water with exhaust gas discharged from the gas engine 2 to the high-pressure steam path 14. In the configuration in which the recovery means B is provided, power generation for converting the energy of the steam discharged from the cooling means C to the upstream low-pressure steam path 3 into mechanical rotational force. Means D and an auxiliary generator 5 driven by the mechanical torque of the power generating means D are provided.
The power generation means D is constituted by the steam turbine 4.

A fuel gas such as city gas is supplied to the gas engine 2 through a fuel supply path 6. The cooling means C includes an engine jacket 7, a steam / water separator 8, and a cooling water circulation path 9 connecting the engine jacket 7 and the steam / water separator 8. The cooling water is circulated and supplied to the engine jacket 7 through the cooling water circulation path 9, the cooling water is boiled in the engine jacket 7 by heat generated from the gas engine 2, and the generated steam is separated by the steam separator 8. , And is configured to be discharged to the well-side low-pressure steam path 3. Incidentally, reference numeral 10 in FIG. 1 denotes a cooling water supply passage for supplying cooling water to the steam separator 8.

The high-pressure low-pressure steam passage 3 is connected to the steam turbine 4, and low-pressure steam is supplied to the steam turbine 4 through the low-pressure steam passage 3 to drive the steam turbine 4. Further, steam is discharged from the steam turbine 4 to the lower-side low-pressure steam path 15. The output shaft 4 a of the steam turbine 4 is connected to the auxiliary generator 5 to drive the auxiliary generator 5.

The exhaust heat recovery means B comprises a water supply passage 11 and an exhaust gas heat exchanger 13 for heating and evaporating water supplied from the water supply passage 11 by exhaust gas of the gas engine 2 supplied through the upstream exhaust gas passage 12. It is configured with
The steam generated in the exhaust gas heat exchanger 13 is transferred to the high-pressure steam path 1
4 to be discharged. Exhaust gas heat exchanger 1
The exhaust gas passing through 3 is discharged to the lower exhaust gas passage 17.

The electric power generated by the engine-driven generator 1 and the electric power generated by the auxiliary generator 5 are output through a power output path 16. Therefore, in the cogeneration system according to the first embodiment, the power output path 16
, High-pressure steam obtained through the high-pressure steam path 14, and steam obtained through the lower-side low-pressure steam path 15.

An example of the result of evaluating the power generation output of the auxiliary generator 5 using the cogeneration system configured as described above is shown below. The rated power output of the engine-driven generator 1 in this cogeneration system was 520 kW.
The engine was driven so that a rated output could be obtained from the engine-driven generator 1.

[Conditions of low-pressure steam generated by cooling means C] Pressure: 1 kg / cm ² G Flow rate: 700 kg / h Temperature: 120 ° C. [Steam turbine 4 conditions] Turbine runner rotation speed: 3600 rpm Outlet steam pressure : 0Kg / cm ² G [Output of auxiliary generator 5] 12kW

Hereinafter, the second to twelfth embodiments will be described. The same reference numerals are given to the same components and components having the same functions as those of the first embodiment in order to avoid redundant description. The description will be omitted, and a configuration different from the first embodiment will be mainly described.

[Second Embodiment] Hereinafter, based on FIG.
A second embodiment of the present invention will be described. As shown in FIG. 2, in the cogeneration system according to the second embodiment, in addition to the configuration of the cogeneration system shown in the first embodiment, a power generation unit is provided by exhaust gas passing through the exhaust heat recovery unit B. A steam heating heat exchanger 18 for heating low-pressure steam supplied to the steam turbine 4 as D is provided.

The steam heating heat exchanger 18 is provided so as to exchange heat between the exhaust gas flowing through the lower exhaust gas passage 17 and the low pressure steam flowing through the upper low pressure steam passage 3. The low-pressure steam flowing through the passage 3 is heated. That is, the configuration is such that the saturated steam generated by the cooling means C is superheated by the exhaust gas in the steam heating heat exchanger 18 to become superheated steam, and the steam turbine 4 is driven by the superheated steam. Therefore, the output of the auxiliary generator 5 can be increased as compared with the cogeneration system shown in the first embodiment. Further, since the steam turbine 4 is driven by the superheated steam, the corrosion of the turbine runner can be suppressed and the durability can be improved as compared with the case where the steam turbine 4 is driven by the saturated steam.

An example of the result of evaluating the power output by the auxiliary generator 5 using the cogeneration system according to the second embodiment is shown below. Note that the rated power output of the engine-driven generator 1 in this cogeneration system is the same as that of the first embodiment.
0 kW, and in the following evaluation, operation was performed so that the rated output could be obtained from the engine-driven generator 1.

[Conditions of low-pressure steam generated by cooling means C] Pressure: 1 Kg / cm ² G Flow rate: 700 Kg / h Temperature: 120 ° C [Conditions of heat exchanger 18 for steam heating] Temperature of exhaust gas: 160 ° C Exhaust gas flow rate: 1723Nm ³ / h Inlet steam temperature: 120 ° C Outlet steam temperature: 150 ° C [Conditions of steam turbine 4] Turbine runner rotation speed: 3600 rpm Outlet steam pressure: 0 Kg / cm ² G [Auxiliary generator 5 output] 15 kW

[Third Embodiment] Hereinafter, based on FIG.
A third embodiment of the present invention will be described. The cogeneration system according to the third embodiment includes an engine-driven generator 1, a gas engine 2 that drives the engine-driven generator 1, a cooling unit C, and an exhaust heat recovery unit B.
In the configuration provided in the same manner as in the first embodiment, the cooling means C
Power generating means D for converting the energy of the steam discharged from the steam into the low-pressure steam path 3 on the upstream side into mechanical torque, and an auxiliary generator 5 driven by the mechanical torque of the power generator D In the third embodiment, the power generating means D is constituted by a positive displacement steam expander E.

By operating a so-called resholl type compressor as a steam expander, it functions as a positive displacement steam expander E. That is, the steam from the cooling means C is supplied to the discharge port when the Rischholm compressor is operated as a compressor, and the input shaft when the compressor is operated as an output shaft and the discharge when the compressor is operated as a compressor. By operating the output shaft with the steam supplied from the outlet to rotate the output shaft, the Richholm-type compressor is operated as a steam expander. Hereinafter, the Resholm type compressor operated in a state of operating as a steam expander is referred to as a Resholm type steam expander 20. Then, the air supply port of the reschorm type steam expander 20 (corresponding to the discharge port when operating as a compressor).
The lower-side low-pressure steam passage 3 is connected to the lower side, and the lower-side low-pressure steam passage 15 is connected to the exhaust port.
Is connected to the auxiliary generator 5 to drive the auxiliary generator 5.

An example of the result of evaluating the power output by the auxiliary generator 5 using the cogeneration system configured as described above is shown below. Note that, similarly to the first embodiment, the rated power output of the engine-driven generator 1 is 52
0 kW, and in the following evaluation, operation was performed so that the rated output could be obtained from the engine-driven generator 1.

[Conditions of low-pressure steam generated by cooling means C] Pressure: 1 kg / cm ² G Flow rate: 700 kg / h Temperature: 120 ° C [Output of auxiliary generator 5] 11.1 kW

[Fourth Embodiment] Hereinafter, based on FIG.
A fourth embodiment of the present invention will be described. As shown in FIG. 4, in the cogeneration system according to the fourth embodiment, in addition to the configuration of the cogeneration system shown in the above third embodiment, power generation means is provided by exhaust gas passing through the exhaust heat recovery means B. A steam heating heat exchanger 18 for heating the low-pressure steam supplied to the D-scholl-type steam expander 20 as D is provided.

The steam heating heat exchanger 18 exchanges heat between the exhaust gas flowing through the lower exhaust passage 17 and the low-pressure steam flowing through the upper low-pressure steam passage 3 in the same manner as in the second embodiment. So that the low-pressure steam flowing through the upstream low-pressure steam path 3 is heated, and the saturated steam generated by the cooling means C is superheated by the exhaust gas in the steam heating heat exchanger 18. The superheated steam is used, and the superheated steam is used to drive the Risholm-type steam expander 20. Therefore, the output of the auxiliary generator 5 is set to 20 to
It can be increased by about 25%. In addition, since the reschorm-type steam expander 20 is driven by superheated steam, the durability can be improved as compared with the case of being driven by saturated steam.

[Fifth Embodiment] Hereinafter, based on FIG.
A fifth embodiment of the present invention will be described. The cogeneration system according to the fifth embodiment is provided with a vacuum pump 21 as a depressurizing means for depressurizing the exhaust side of the Richorm-type steam expander 20 in addition to the configuration of the cogeneration system shown in the third embodiment. is there.

More specifically, a condenser 22 is connected to the lower-side low-pressure steam path 15 connected to the exhaust port of the Rischholm type steam expander 20, and an exhaust path 23 is connected to the gas phase of the condenser 22. The vacuum pump 21 is connected through the, and the pressure on the exhaust side of the Richholm-type steam expander 20 is reduced.
Also, the liquid phase portion of the condenser 22 and the cooling water supply path 10 are connected by a condenser path 25 provided with a condenser pump 24, and the condensate is returned to the steam separator 8 as cooling water. It is configured as follows. Reference numeral 26 in FIG. 5 denotes a cooling water passage through which cooling water flows to cool the condenser 22, and 27 denotes a cooling water passage 26.
This is a cooling water pump that allows cooling water to flow through.

Therefore, since the exhaust side of the reshoil type steam expander 20 is depressurized by the vacuum pump 21, the rotational force of the output shaft 20a of the reshroom type steam expander 20 is increased as compared with the cogeneration system in the third embodiment. As a result, the power output from the auxiliary generator 5 increases. still,
In order to reduce the pressure on the exhaust side of the Rhischholm-type steam expander 20, auxiliary equipment including a vacuum pump 21, a condensate pump 24 and a cooling water pump 27 is required, and although electric power for driving the auxiliary equipment is required, , Its auxiliary equipment drive power is
Since it is smaller than the increase in the power generation output of the auxiliary generator 5 due to the pressure reduction on the exhaust side of the reshroom type steam expander 20, the effective power generation output increases. Note that the actual increment of the power generation output is a value obtained by subtracting the auxiliary device driving power from the power generation output of the auxiliary generator 5.

An example of the result of evaluating the power output by the auxiliary generator 5 using the cogeneration system configured as described above is shown below. Note that, similarly to the first embodiment, the rated power output of the engine-driven generator 1 is 52
0 kW, and the pressure on the exhaust side of the Risholm type steam expander 20 is reduced to −0.8 kg / cm ² G.

[Conditions of low-pressure steam generated by cooling means C] Pressure: 1 kg / cm ² G Flow rate: 700 kg / h Temperature: 120 ° C [Output of auxiliary generator 5] 32.5 kW [Drive of auxiliary equipment] Power] 5.5 kW [Actual power generation output] 27.0 kW

[Sixth Embodiment] Hereinafter, based on FIG.
A sixth embodiment of the present invention will be described. As shown in FIG. 6, in the cogeneration system according to the sixth embodiment, in addition to the configuration of the cogeneration system shown in the fifth embodiment, a power generation unit is provided by exhaust gas passing through the exhaust heat recovery unit B. A steam heating heat exchanger 18 for heating the low-pressure steam supplied to the D-scholl-type steam expander 20 as D is provided.

Accordingly, the saturated steam generated by the cooling means C is superheated by the exhaust gas in the steam heating heat exchanger 18, and the superheated steam drives the reshroom type steam expander 20, so that the fifth As compared with the cogeneration system shown in the embodiment, the output of the auxiliary generator 5 is increased, and the actual increment of the power generation output can be increased by about 20 to 25%.

[Seventh Embodiment] Hereinafter, based on FIG.
A seventh embodiment of the present invention will be described. The cogeneration system according to the seventh embodiment includes an engine-driven generator 1, a gas engine 2 that drives the engine-driven generator 1, a cooling unit C, and an exhaust heat recovery unit B.
In the configuration provided in the same manner as in the first embodiment, the cooling means C
Power generation means D for converting the energy of the steam discharged from the steam generator into the low-pressure steam passage 3 on the upstream side into mechanical rotational force is connected to the gas engine 2 so as to assist the rotation thereof.

The power generating means D comprises a steam turbine 4 similar to that of the first embodiment, and similarly to the first embodiment, connects the upstream low-pressure steam path 3 to the steam turbine 4 to provide the upstream low-pressure steam. Low-pressure steam is passed through a steam passage 3 to a steam turbine 4
To drive the steam turbine 4 so that steam is discharged from the steam turbine 4 to the lower-side low-pressure steam path 15. Then, by connecting the crankshaft 2 a of the gas engine 2 and the output shaft 4 a of the steam turbine 4 by a one-way coupling 28, the steam turbine 4 is
It is connected to the gas engine 2 so as to assist its rotation.

As shown in FIG. 13, the one-way coupling 28 includes a first connecting member 28a and a second connecting member 28b which are disposed so as to mesh with each other in a facing state.
A first shaft portion 28c supporting the connecting member 28a so as to be integrally rotatable while being movable in the axial direction, and a second connecting member 2
A second shaft portion 28d which is connected to rotate the shaft 8b integrally;
And a spring body 28e for urging the first connecting member 28a to abut the second connecting member 28b.
The surface of the first connecting member 28a facing the second connecting member 28b is provided with a plurality of teeth having a shape in which the upper side in the rotational direction is inclined in a ring shape.
b, the surface facing the first connecting member 28a
A plurality of teeth are provided in a ring shape so as to mesh with the plurality of teeth of the connecting member 28a. And the first shaft portion 2
8c is connected to the crankshaft 2a of the gas engine 2 and the second
The shaft 28d is connected to the output shaft 4a of the steam turbine 4,
The steam turbine 4 is driven such that its rotation direction and rotation speed are the same as those of the gas engine 2, or such that the rotation direction is the same as that of the gas engine 2 and the rotation speed is higher than that of the gas engine 2, The steam turbine 4 is configured to assist the rotation of the gas engine 2.

Accordingly, the output of the gas engine 2 is increased by the amount that the rotation is assisted by the steam turbine 4,
The power output of the engine-driven generator 1 increases. Incidentally, the increase in the power output of the engine-driven generator 1 is substantially the same as the power output of the auxiliary generator 5 in the first embodiment.

[Eighth Embodiment] Hereinafter, based on FIG.
An eighth embodiment of the present invention will be described. As shown in FIG. 8, in the cogeneration system according to the eighth embodiment, in addition to the configuration of the cogeneration system shown in the seventh embodiment, the power generation means is provided by the exhaust gas passing through the exhaust heat recovery means B. A steam heating heat exchanger 18 for heating low-pressure steam supplied to the steam turbine 4 as D is provided. Therefore, the cooling means C
Is heated by the exhaust gas in the steam heating heat exchanger 18, and the steam turbine 4 is driven by the superheated steam. The output of the engine-driven generator 1 can be further increased.

[Ninth Embodiment] Hereinafter, based on FIG.
A ninth embodiment of the present invention will be described. The cogeneration system according to the ninth embodiment includes an engine-driven generator 1, a gas engine 2 that drives the engine-driven generator 1, a cooling unit C, and an exhaust heat recovery unit B.
In the configuration provided in the same manner as in the first embodiment, the cooling means C
Power generation means D for converting the energy of the steam discharged from the steam generator into the low-pressure steam passage 3 on the upstream side into mechanical rotational force is connected to the gas engine 2 so as to assist the rotation thereof.

The power generating means D is constituted by a reshroom type steam expander 20 as a positive displacement type steam expander E similar to the third embodiment. The low-pressure steam passage 3 is connected, and the lower-side low-pressure steam passage 15 is connected to the exhaust port. Then, by connecting the crankshaft 2a of the gas engine 2 and the output shaft 20a of the Richorm-type steam expander 20 with a one-way coupling 28 shown in FIG. On the other hand, they are connected to assist the rotation. More specifically, the crankshaft 2 a of the gas engine 2 is connected to the first shaft portion 28 c of the one-way coupling 28, and the output shaft 20 a of the Rischholm type steam expander 20 is connected to the second shaft portion 28 of the one-way coupling 28.
d, so that the rotation direction and the rotation speed of the Rischholm type steam expander 20 are the same as those of the gas engine 2 or the rotation direction is the same as that of the gas engine 2 and the rotation speed is higher than that of the gas engine 2. The speed is also increased so that the rotation of the gas engine 2 is assisted by the Richorm-type steam expander 20.

Accordingly, the output of the gas engine 2 is increased by the amount of the rotation assisted by the Richolm-type steam expander 20, so that the output of the engine-driven generator 1 is increased. Incidentally, the increase in the power generation output of the engine-driven generator 1 is substantially the same as the power generation output of the auxiliary generator 5 in the third embodiment.

[Tenth Embodiment] Hereinafter, a tenth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 10, in the cogeneration system according to the tenth embodiment, in addition to the configuration of the cogeneration system shown in the ninth embodiment,
A steam heating heat exchanger 18 is provided for heating low-pressure steam supplied to the Rishholm-type steam expander 20 as power generation means D by the exhaust gas passing through the exhaust heat recovery means B. Accordingly, the saturated steam generated by the cooling means C is superheated by the exhaust gas in the heat exchanger 18 for steam heating, and the superheated steam drives the Richholm-type steam expander 20. The output of the engine-driven generator 1 can be further increased as compared with the illustrated cogeneration system.

[Eleventh Embodiment] An eleventh embodiment of the present invention will be described below with reference to FIG. The cogeneration system according to the eleventh embodiment is provided with a vacuum pump 21 as a depressurizing means for depressurizing the exhaust side of the Richorm-type steam expander 20 in addition to the configuration of the cogeneration system shown in the ninth embodiment. is there.

Therefore, since the exhaust side of the reshoil type steam expander 20 is depressurized by the vacuum pump 21, the rotational force of the output shaft 20a of the reshroom type steam expander 20 is increased as compared with the cogeneration system in the ninth embodiment. Thus, the power output from the engine-driven generator 1 increases. In addition, in order to reduce the pressure on the exhaust side of the Risholm-type steam expander 20, auxiliary equipment including a vacuum pump 21, a condensate pump 24, and a cooling water pump 27 is required, and electric power for driving the auxiliary equipment is required. However, the auxiliary device driving power is smaller than the increase in the power generation output of the engine-driven generator 1 due to the reduced pressure on the exhaust side of the Richolm type steam expander 20, so that the effective power increases. still,
The actual increment of the power generation output is a value obtained by subtracting the power for driving the auxiliary equipment from the increase in the power generation output of the engine-driven generator 1 due to the pressure reduction on the exhaust side of the Rischholm type steam expander 20.
Incidentally, in the cogeneration system according to the eleventh embodiment, similarly to the fifth embodiment, the exhaust side of the Richorm-type steam expander 20 is set to −0.8 kg / cm ^2.
When the pressure is reduced to G, the actual increment of the power generation output is substantially the same as the actual increment of the power generation output in the cogeneration system of the fifth embodiment.

[Twelfth Embodiment] Hereinafter, a twelfth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 12, in the cogeneration system according to the twelfth embodiment, in addition to the configuration of the cogeneration system shown in the eleventh embodiment, power generation means is provided by exhaust gas passing through the exhaust heat recovery means B. A steam heating heat exchanger 18 for heating the low-pressure steam supplied to the D-scholl-type steam expander 20 as D is provided.

Therefore, the saturated steam generated by the cooling means C is superheated by the exhaust gas in the steam heating heat exchanger 18 and the superheated steam drives the reshroom type steam expander 20. The engine-driven generator 1 is more suitable than the cogeneration system shown in the embodiment.
Is further increased, and the actual increment of the power generation output can be increased.

[Another Embodiment] Next, another embodiment will be described. (B) The operating conditions of the cogeneration system
The conditions exemplified in the above embodiments, for example, the first condition
The embodiment is not limited to the various conditions shown for evaluating the power generation output of the auxiliary generator 5, but can be appropriately changed according to the specifications of the cogeneration system to which the present invention is applied. For example, in each of the above-described first to sixth embodiments, the operation is performed such that a rated output is obtained from the engine-driven generator 1, and the generated output of the cogeneration system as a whole is output from the auxiliary generator 5. Although the case where the engine is operated so as to be larger than the rated output of the engine-driven generator 1 by the power output of the engine-driven generator 1, the power generation output of the cogeneration system as a whole is 1 may be operated so as to be the same as the rated output. in this case,
Since the power output of the engine-driven generator 1 can be reduced by the power output of the auxiliary generator 5, the amount of fuel gas corresponding to the power output of the auxiliary generator 5 can be reduced.

In each of the seventh to twelfth embodiments, the power output of the engine-driven generator 1 is set to the original rated output of the engine-driven generator 1 in a state where the present invention is not employed. During operation, the rotation of the engine-driven generator 1 is assisted by the power generation means D, so that the amount of fuel gas corresponding to the increase in the power generation output of the engine-driven generator 1 can be reduced. When the supply amount of the fuel gas is increased from that state, the power generation output can be made larger than the original rated output of the engine-driven generator 1 in a state where the present invention is not employed.

(B) As a specific configuration of the positive displacement steam expander E, in the above-described embodiment, a rotary type compressor, which is a kind of screw compressor among rotary compressors, is operated as a steam expander. Thus, the case of functioning as the positive displacement steam expander E is described above, but the specific configuration of the positive displacement steam expander E is not limited to this. For example, a screw-type compressor other than the Rishholm-type compressor may function as the steam expander. Further, a rotary compressor other than the screw compressor may function as the steam expander.
Further, the reciprocating compressor may function as a steam expander. (C) The specific configuration of the power generation means D is not limited to the steam turbine 4 or the positive displacement steam expander E exemplified in the above embodiment, and various types can be applied. A compressor configured to function as a steam expander may be applied.

(D) In each of the above-described first to sixth embodiments, the auxiliary generator 5 can be either a synchronous type or an induction type. Incidentally, since the engine-driven generator 1 is of a synchronous type, if the auxiliary generator 5 is of an induction type, the induction-type auxiliary generator 5 is guided by the synchronous engine-driven generator 1 to rotate. Therefore, the speed control function is not required, and the cost can be reduced.

(E) In the above-described embodiment, the case where the one-way coupling 28 is constituted by a meshing type is exemplified. However, the specific structure of the one-way coupling 28 can be variously changed, and is constituted by a friction type. May be. When the gas engine 2 and the power generation means D are connected by a one-way coupling 28 and the rotation of the gas engine 2 is assisted by the power generation means D, the rotation speed of the power generation means D is higher than that of the gas engine 2. , The one-way coupling 28 may be provided with an acceleration / deceleration gear.

(F) In each of the above embodiments, the gas engine 2 which uses various gas fuels such as propane gas as fuel instead of the city gas exemplified in each embodiment as fuel is used. can do.
Further, the engine may be a fuel that uses a liquid fuel such as gasoline or light oil instead of a fuel that uses gaseous fuel as exemplified in the above embodiments.

[Brief description of the drawings]

FIG. 1 is a block diagram of a cogeneration system according to a first embodiment.

FIG. 2 is a block diagram of a cogeneration system according to a second embodiment.

FIG. 3 is a block diagram of a cogeneration system according to a third embodiment.

FIG. 4 is a block diagram of a cogeneration system according to a fourth embodiment.

FIG. 5 is a block diagram of a cogeneration system according to a fifth embodiment.

FIG. 6 is a block diagram of a cogeneration system according to a sixth embodiment.

FIG. 7 is a block diagram of a cogeneration system according to a seventh embodiment.

FIG. 8 is a block diagram of a cogeneration system according to an eighth embodiment.

FIG. 9 is a block diagram of a cogeneration system according to a ninth embodiment;

FIG. 10 is a block diagram of a cogeneration system according to a tenth embodiment.

FIG. 11 is a block diagram of a cogeneration system according to an eleventh embodiment.

FIG. 12 is a block diagram of a cogeneration system according to a twelfth embodiment.

FIG. 13 is a development view showing a schematic configuration of a one-way coupling.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine-driven generator 2 Engine 3 Steam recovery path 4 Turbine 5 Auxiliary generator 18 Heat exchanger 21 Decompression means B Exhaust heat recovery means C Cooling means D Power generation means E Positive displacement steam expander

Claims (6)

[Claims] 1. An engine for driving an engine-driven generator, and cooling for cooling the engine while supplying cooling water to the engine and discharging steam generated by heat generated from the engine to a steam recovery path. A power generation means for converting the energy of steam discharged from the cooling means to the steam recovery path into a mechanical rotation force, and a mechanical rotation of the power generation means. A cogeneration system with an auxiliary generator driven by power. 2. An engine for driving an engine-driven power generator, and cooling for cooling the engine while supplying cooling water to the engine and discharging steam generated by heat generated from the engine to a steam recovery path. A cogeneration system provided with a means, wherein power generation means for converting energy of steam discharged from the cooling means to the steam recovery path into mechanical rotational force, the rotation of the engine with respect to the engine, A cogeneration system that is connected to assist. 3. An exhaust heat recovery means for recovering exhaust heat from exhaust gas discharged from the engine, wherein the exhaust gas passing through the exhaust heat recovery means heats the steam supplied to the power generation means. The cogeneration system according to claim 1, further comprising a heat exchanger. 4. The cogeneration system according to claim 1, wherein said power generation means comprises a turbine. 5. The cogeneration system according to claim 1, wherein said power generating means is constituted by a positive displacement steam expander. 6. The cogeneration system according to claim 5, further comprising pressure reducing means for reducing the pressure on the exhaust side of the positive displacement steam expander.