JP2021076073A - Gas engine system - Google Patents

Abstract

To provide a gas engine system that can control a supply air temperature to make it suitable for an operation request for various types of gas engines regardless of an atmospheric condition.SOLUTION: A gas engine system includes: a gas engine 2; a power generator 3 generating electric power by using rotating power of the gas engine 2; a supercharger 4 including a compressor 10 and a turbine 11; a supply air cooling device 5 cooling supply air compressed by the compressor 10 by using cooling water cooled by the atmosphere; and an intake air temperature adjustment device 6 adjusting a temperature of intake air to be supplied from an intake air introduction part 8 introducing the atmosphere to the compressor. The intake air temperature adjustment device 6 includes: an exhaust heat recovery part 44 recovering exhaust heat generated in the gas engine 2; a temperature adjustment device 25 adjusting a temperature of intake air by using the recovered exhaust heat; and a controller 26 controlling the temperature adjustment device 25. The controller 26 acquires a temperature of supply air to be supplied to the gas engine 2 or a temperature of burned gas discharged from the gas engine 2, and controls the temperature of intake air so that the acquired temperature becomes a predetermined target temperature.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gas engine system that generates electricity using a gas engine.

In a gas engine system that generates electricity using a gas engine, a supercharger that compresses the atmosphere (intake) is provided in order to improve the efficiency of the gas engine and increase the power generation efficiency of the gas engine system. Since the air (supply air) compressed by the compressor of the supercharger becomes hot due to compression, the gas engine system provides an air supply cooling device for cooling the high temperature supply air before supplying it to the gas engine. I have.

The air supply cooling device is often composed of, for example, two coolers. The high-temperature air supply from the supercharger first passes through the first cooler and is first cooled. As the cooling water used at this time, relatively high temperature cooling water after cooling the gas engine is used. The air supply that has been primarily cooled by the first cooler passes through the second cooler and is supplied to the gas engine. The cooling water of the second cooler is configured to be cooled by using cooling water supplied from a cooling water supply facility installed outdoors, such as a cooling source or a radiator that is affected by atmospheric temperature, humidity, or the like. .. The supply air cooling device can premix the supply air and the fuel so as to have an air-fuel ratio close to the optimum by controlling the temperature of the supply air supplied to the gas engine to an appropriate temperature. The mixture of air-fuel ratios burns in the gas engine, and as a result, the gas engine can be operated near the maximum efficiency point. As the supply air temperature t ₂ of the second cooler outlet becomes a target temperature t _s2 predetermined, and is configured to adjust the temperature and flow rate of the cooling water.

The second cooler of the supply air cooling device cools the outlet air supply of the first cooler by using the cooling water supplied from the cooling water supply device installed outdoors. The cooling water supplied from the cooling water supply device installed outdoors to the air supply cooling device is strongly affected by atmospheric conditions (atmospheric temperature, relative temperature, atmospheric pressure, solar heat, wind speed, etc.), so the cooling water temperature is It changes depending on the atmospheric conditions. Therefore, in areas with high temperature and humidity throughout the year, areas where the air conditions in summer and winter are significantly different, or areas where air conditions change significantly during the day and night, if the above gas engine system is introduced and used as it is, it will be second. Due to the change in the cooling water temperature of the cooler, it is not possible to control the _{predetermined target temperature t s2 of the supply air.} Therefore, the supply air is premixed with the fuel while being higher than the _{target temperature t s2, and is burned in the gas engine.} In that case, the air-fuel ratio that can be operated at the highest efficiency point cannot be achieved, and the power generation efficiency is lowered.

Patent Documents 1 to 3 below have been proposed with respect to cooling the intake air temperature (inlet temperature of the supercharger) or the high-temperature air supply at the outlet of the supercharger in the gas engine system as described above. Patent Document 1 discloses that an absorption chiller utilizing the exhaust heat of a gas engine is used instead of the air supply cooling device that cools the cooling water by the atmosphere as described above. Further, Patent Document 2 discloses that the intake air supplied to the turbocharger is used to vaporize the liquefied fuel of the gas engine to cool the intake air by heat exchange with the liquefied fuel. Further, Patent Document 3 discloses that the cooling water for cooling the intake air is cooled by vaporizing the liquefied fuel.

Japanese Unexamined Patent Publication No. 2001-193563 Japanese Unexamined Patent Publication No. 2014-80892 Japanese Unexamined Patent Publication No. 2006-177213

In Patent Document 1, since the air supply cooling device that cools the cooling water by the atmosphere cannot be used as it is, a major design change or specification change is required according to the climatic conditions of the area where the cooling water is introduced. Further, in Patent Document 2, since it is necessary to intersect the introduction path of the liquefied fuel and the introduction path of the air, the structure of the piping or the like becomes complicated. Similarly, in Patent Document 3, since it is necessary to lay a pipe for cooling water between the introduction path for liquefied fuel and the introduction path for air, the structure of the pipe or the like becomes complicated. Further, in Patent Document 2, since the intake air is directly cooled by the heat of vaporization of the liquefied fuel, the temperature of the intake air introduced changes depending on the temperature of the atmosphere. Further, in Patent Document 3, since the temperature of the cooling water is controlled to be constant, the temperature of the intake air introduced changes depending on the temperature of the atmosphere.

In addition, the problem that the temperature of the supply air supplied to the gas engine changes depending on the temperature of the atmosphere is not only when the temperature of the atmosphere is high, but also when introducing such a gas engine system in an area where there is a severe winter season. It can also occur when the temperature of the atmosphere is low. That is, when the temperature of the atmosphere is low, the intake air temperature to be taken in is lower than that of the outside air, and the characteristics and mechanical restrictions of the compressor of the supercharger, such as the low temperature intensity and the intake flow rate limit due to the fixed blade angle (for example). Surging), which makes the compressor unusable. Therefore, it is necessary to install mechanical equipment that switches the intake source from outside air to indoor air, or install indoor intake equipment that constantly supplies indoor air to the gas engine throughout the year. In such a case where the temperature of the atmosphere is low, Patent Documents 1 to 3 have no suggestion. Therefore, in the gas engine system as described above, even if the intake condition changes from the low temperature air in the atmosphere to the relatively high temperature air in the room, the temperature difference of the air is not controlled unless the indoor air temperature is controlled in some way. Nevertheless, indoor air is still hot in the summer and cold in the winter. Thus, the supply air temperature t ₂ regardless of the atmospheric conditions (room conditions) is controlled to a target temperature t _s2, always room conditions whether the premixing so that near optimum air-fuel ratio of the supply air and fuel Therefore, the air-fuel ratio close to the optimum is a matter of course and cannot be controlled.

The present invention solves the above problems, and an object of the present invention is to provide a gas engine system capable of controlling a supply air temperature suitable for operating requirements of various gas engines regardless of atmospheric conditions.

The gas engine system according to one aspect of the present invention includes a gas engine, a generator that generates heat by the rotational power of the gas engine, a compressor that compresses the supply air supplied to the gas engine, and discharge from the gas engine. A supercharger having a turbine that generates power from the gas after combustion, an air supply cooling device that cools the supply air compressed by the compressor, and the compressor from an intake introduction unit that takes in air. The intake air temperature adjusting device includes an intake air temperature adjusting device for adjusting the temperature of the intake air supplied to the gas engine, and the intake air temperature adjusting device uses an exhaust heat recovery unit for recovering exhaust heat generated by the gas engine and the recovered exhaust heat. A temperature controller for adjusting the temperature of the intake air and a controller for controlling the temperature controller are included, and the controller is the temperature of the supply air supplied to the gas engine or discharged from the gas engine. The temperature of the exhaust air to be generated is acquired, and the temperature of the intake air is controlled so that the acquired temperature becomes a predetermined target temperature.

According to the above configuration, the exhaust heat generated by the air supply cooling device that cools using the cooling water cooled by the atmosphere is recovered, and the exhaust heat is used to supply the temperature of the intake air to the compressor of the turbocharger. Is adjusted. At this time, the temperature of the intake air is adjusted so that the temperature of the supply air supplied to the gas engine or the temperature of the exhaust gas discharged from the gas engine becomes a predetermined target temperature. Therefore, the temperature can be controlled to be suitable for the operating requirements of the gas engine regardless of the atmospheric conditions.

The temperature controller may include a cooling water cooling device that cools the cooling water for cooling the intake air by using the exhaust heat recovered by the exhaust heat recovery unit.

According to the above configuration, even if the temperature of the atmosphere is high and the temperature of the supply air cannot be lowered to the target temperature by the supply air cooling device alone, the cooling water cooling device using the exhaust heat generated from the gas engine is used. By pre-cooling the intake air with the produced cold water before compressing it with the supercharger, the compressor outlet temperature is lowered, so that the supply air temperature can be controlled to the target temperature.

The exhaust heat recovery unit recovers the exhaust heat as hot water or steam, and the temperature controller has a cooling pipe that supplies cooling water from the cooling water cooling device to the intake air introduction unit, and the exhaust heat recovery unit. A heating pipe that supplies the hot water from the above to the intake air introduction unit to heat the intake air, and a pipe switching unit that switches the pipe connecting to the intake air introduction unit between the cooling pipe and the heating pipe. , May be provided.

According to the above configuration, even if the temperature of the atmosphere is high and the air supply cooling device cannot lower the temperature of the supply air to the target temperature, the air is taken in by the cooling water cooled by the cooling water cooling device using the exhaust heat. Can be pre-cooled before being compressed by the compressor of the supercharger. Furthermore, even if the atmospheric temperature is low and the atmospheric temperature falls below the lower limit of the intake air temperature in the turbocharger compressor, it is recovered as hot water without using a complicated mechanism such as switching from outside air intake to indoor intake. By supplying the exhaust heat to the intake air introduction unit, the intake air can be preheated before being compressed by the compressor of the supercharger. Further, the pipe connected to the intake intake portion is configured to be switchable between a cooling pipe through which cooling water flows and a heating pipe through which hot water flows. Therefore, even when the gas engine system is installed in an area where the temperature of the atmosphere changes greatly depending on the season, it is possible to eliminate the need to make a large-scale change of the intake equipment and the intake method depending on the season. Even in the seasons and seasons when the atmospheric temperature is low, the atmospheric temperature is not constant and constantly changes, so it is very difficult to switch the intake method sequentially in response to the change.

The exhaust heat recovery unit may recover the exhaust heat as hot water or steam, and the cooling water cooling device may be a hot water or steam absorption chiller that produces the cooling water using the hot water or steam.

According to the above configuration, cooling water for cooling the intake air can be easily produced by utilizing the exhaust heat.

The exhaust heat recovery unit recovers the exhaust heat as hot water, and the temperature controller provides a heating pipe that supplies the hot water from the exhaust heat recovery unit to the intake air introduction unit in order to heat the intake air. You may prepare.

According to the above configuration, it is not necessary to switch the intake method from outdoor to indoor even when the temperature of the atmosphere is low and the intake air temperature is low. That is, by supplying the exhaust heat recovered as hot water to the intake intake section, the intake air can be preheated before the intake air enters the compressor of the supercharger, so that the air supply is supplied by the air supply cooling device. The temperature can be controlled to the target temperature.

The controller has a first control mode in which the target temperature set for heating the air supply is set as a predetermined first target temperature, and the target temperature set for heating the air supply. May be feasible by switching between the second control mode in which the second target temperature is higher than the first target temperature.

According to the above configuration, since the intake air temperature is controlled so that the supply air temperature becomes the second target temperature higher than the first target temperature in the first control mode, the gas temperature after combustion rises and the exhaust gas. The temperature also rises. Therefore, the amount of exhaust heat in the exhaust gas path increases, and the amount of heat recovery in the exhaust gas path increases. Since the target temperature of the supply air temperature is controlled to the second target temperature higher than the first target temperature, the air-fuel ratio due to this is deviated from the air-fuel ratio close to the optimum, and the power generation efficiency is lowered. However, in terms of overall thermal efficiency, the amount of increase in heat recovery is larger than the amount of increase in fuel input as the power generation efficiency decreases, so the overall thermal efficiency of the entire system should be improved. Can be done.

The air supply cooling device includes a first air supply cooler provided in a return path from the gas engine in a first cooling water path for cooling the gas engine, and a second cooling water path different from the first cooling water path. A second air supply cooler provided in the cooling water path is provided, and the first air supply cooler is the second air supply cooler in the air supply path between the supercharger and the gas engine. The exhaust heat recovery unit may be provided on the upstream side, and may be provided on the downstream side of the first air supply cooler in the return path of the first cooling water path.

According to the above configuration, the temperature of the intake air can be adjusted in a wider temperature range by recovering the exhaust heat in the return path of the first cooling water path in which the cooling water becomes hotter.

The air supply cooling device includes a first air supply cooler provided in a return path from the gas engine in a first cooling water path for cooling the gas engine, and a second cooling water path different from the first cooling water path. A second air supply cooler provided in the cooling water path is provided, and the first air supply cooler is the second air supply cooler in the air supply path between the supercharger and the gas engine. The exhaust heat recovery unit may be provided on the upstream side and may be provided on the downstream side of the second air supply cooler in the second cooling water path.

According to the above configuration, the air supply is cooled by the first air supply cooler provided on the upstream side of the second air supply cooler in the air supply path, so that the air supply at the inlet of the second air supply cooler The temperature can be lowered in advance. Therefore, it is possible to separately use the exhaust heat recovered from the first air supply cooler having a higher temperature while adjusting the intake air temperature by utilizing the exhaust heat recovered from the second air supply cooler having a lower temperature. Therefore, the exhaust heat can be reused more efficiently.

The air supply cooling device is provided in a first air supply cooler provided in the air supply path between the supercharger and the gas engine, and on the downstream side of the first air supply cooler in the air supply path. A second air supply cooler, a supply air cooling cooling water path for supplying cooling water to each of the first air supply cooler and the second air supply cooler, and the gas engine for cooling the gas engine. A gas engine cooling path provided separately from the supply air cooling cooling water path may be provided, and the exhaust heat recovery unit may be provided on the downstream side of the gas engine in the gas engine cooling path.

According to the above configuration, the cooling water path for cooling the supply air for cooling the supply air and the cooling path for the gas engine for cooling the gas engine are configured as separate paths, so that the downstream side of the cooling path for the gas engine It is possible to control the supply air temperature to the target temperature even when the supply air temperature at the outlet of the supercharger is lower than that in the case where the first air supply cooler is provided. Therefore, the supply air temperature can be adjusted by the first air supply cooler and the second air supply cooler in a wider temperature range.

The compressor blade of the supercharger may have a highly efficient shape optimized for a temperature in a predetermined range based on a target temperature set for the temperature of the supply air. Further, the turbine blade of the turbocharger may have a highly efficient shape optimized for a temperature in a predetermined range based on a target temperature set for the temperature of the post-combustion gas.

According to the above configuration, the temperature of the intake air at the supercharger inlet can be maintained within a predetermined range by maintaining the temperature of the supply air at the target temperature regardless of the temperature of the atmosphere by controlling the temperature of the intake air. it can. For this reason, the compressor blades of the turbocharger, which were conventionally designed to operate in a wide temperature range as in the case of outside air intake, are made into a shape suitable for the intake temperature within the predetermined temperature. It is possible to improve the efficiency of adiabatic compression in the compressor of the turbocharger. Further, according to the above configuration, since the air supply temperature can be stabilized, the combustion state in the gas engine is stabilized, and the temperature of the post-combustion gas discharged from the gas engine is stabilized. Therefore, by making the turbine blades of the turbocharger, which was conventionally designed to operate in a wide temperature range, into a shape suitable for the gas temperature after combustion, it is possible to improve the efficiency of the turbocharger turbine. As a result, the efficiency of the gas engine can be improved.

The controller may acquire a predetermined value indicating the properties of the fuel gas supplied to the gas engine, and set the target temperature to a value corresponding to the predetermined value.

According to the above configuration, the supply air temperature is controlled to be a target temperature suitable for the properties of the fuel gas, so that the gas engine can be operated at the maximum efficiency point.

According to the present invention, it is possible to control the supply air temperature suitable for the operating requirements of various gas engines regardless of the atmospheric conditions.

FIG. 1 is a block diagram showing a schematic configuration of a gas engine system according to a first embodiment of the present invention. FIG. 2 is a diagram showing a schematic graph of the intake air temperature and the supply air temperature with respect to the atmospheric temperature when the control according to the first embodiment is performed. FIG. 3 is a graph showing an example of the relationship between the target temperature of the supply air temperature and the methane value of the fuel gas. FIG. 4 is a graph showing an example of the relationship between the calorific value of the fuel gas and the target temperature of the supply air temperature. FIG. 5 is a block diagram showing a schematic configuration of a gas engine system according to a first modification of the first embodiment of the present invention. FIG. 6 is a block diagram showing a schematic configuration of a gas engine system according to a second modification of the first embodiment of the present invention. FIG. 7 is a block diagram showing a schematic configuration of a gas engine system according to a modification 3 of the first embodiment of the present invention. FIG. 8 is a block diagram showing a schematic configuration of a gas engine system according to a second embodiment of the present invention. FIG. 9 is a graph showing an example of the relationship between the target temperature of the supply air temperature according to each priority mode with respect to the methane value of the fuel gas. FIG. 10 is a graph showing an example of the relationship between the calorific value of the fuel gas and the target temperature of the supply air temperature according to each priority mode. FIG. 11 is a diagram showing a schematic graph of the intake air temperature and the supply air temperature with respect to the atmospheric temperature when the control according to the second embodiment is performed. FIG. 12 is a block diagram showing a schematic configuration of a gas engine system according to a third embodiment of the present invention. FIG. 13 is a block diagram showing a schematic configuration of a gas engine system according to a first modification of the third embodiment of the present invention. FIG. 14 is a block diagram showing a schematic configuration of the gas engine system 1E according to the second modification of the third embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, the same reference numerals will be given to elements having the same or the same function throughout all the figures, and duplicate description thereof will be omitted.

[Embodiment 1]
Hereinafter, embodiments of the present invention will be described. FIG. 1 is a block diagram showing a schematic configuration of a gas engine system 1 according to a first embodiment of the present invention. The gas engine system 1 in the present embodiment includes a gas engine 2, a generator 3, a supercharger 4, an air supply cooling device 5, and an intake air temperature adjusting device 6.

In the gas engine 2, fuel gas is supplied into a cylinder (not shown) through a fuel pipe (not shown), and air is supplied through an air supply path 7. A mixture of fuel gas and supply air compresses, burns, and expands in the cylinder, and the cylinder reciprocates accordingly to generate power. The cylinders are not single cylinders, but are composed of a plurality of cylinders, and are connected by one axis so that the reciprocating motion having a time difference between the plurality of cylinders is converted into a rotary motion. For example, natural gas is supplied to the gas engine 2 as a fuel gas. The generator 3 is connected to the gas engine 2 and is configured to generate electricity by the rotational power of the gas engine 2.

The supercharger 4 takes in the intake air supplied to the gas engine 2 from the outside, compresses it to the pressure required for the gas engine 2 by the compressor 10, and supplies the high-pressure air to the cylinder of the gas engine 2 as air supply. .. The post-combustion gas discharged from the gas engine 2 is expanded by the turbine 11, and the compressor 10 is rotated by the power thereof. Therefore, the compressor 10 and the turbine 11 are connected by a rotating shaft 9 in order to transmit power. In the compressor 10, a plurality of compressor blades (blades) are attached at an appropriate blade angle that meets the requirements of the gas engine 2 used.

The intake air introduction unit 8 may be configured to introduce the air (outside air) outside the building, or may be configured to introduce the indoor air inside the building. Further, the intake air introduction unit 8 may be configured to be able to switch between a case where the outside air is directly taken in and a case where the room air is supplied as it is, depending on the outside air temperature.

The intake air compressed by the compressor 10 is supplied to the gas engine 2 as supply air through the air supply path 7. In the present specification, "intake-air" means air from the intake introduction unit 8 to the introduction into the compressor 10 of the supercharger 4, and "charge-air" means air. It is defined as meaning the air from the outlet of the compressor 10 of the supercharger 4 to the air supplied to the gas engine 2.

Power is generated by combustion in the gas engine 2, and then the high-temperature post-combustion gas discharged from the gas engine 2 flows into the turbine 11 of the supercharger 4 through the exhaust path 12. The turbine 11 includes a plurality of turbine blades, and generates power by expanding the inflowing high-temperature post-combustion gas. The power is transmitted to the compressor 10 by the rotating shaft 9, and the compressor 10 rotates. The exhaust gas discharged from the turbine 11 is discharged to the atmosphere from the chimney 13 through the exhaust gas path 43.

The exhaust gas path 43 may be provided with an exhaust heat recovery device 45 that recovers the exhaust heat of the exhaust gas. Since the exhaust gas discharged from the gas engine 2 via the turbine 11 has a high temperature, the exhaust heat is recovered and recovered as steam or hot water to produce cold water for building heating, district heating, chillers, and the like. It can be used for other purposes such as a heat source for equipment. The exhaust heat recovery device 45 recovers the exhaust heat of the exhaust gas as steam or hot water.

The supply air cooling device 5 dissipates the air supplied compressed by the compressor 10 of the supercharger 4 to the relatively high-temperature high-temperature cooling water used for cooling the gas engine 2 and the atmosphere to dissipate the cooling water. It is configured to cool using low temperature cooling water supplied from the equipment to be produced. In the present embodiment, the air supply cooling device 5 includes a first air supply cooler 14 and a second air supply cooler 15. The first air supply cooler 14 is provided on the upstream side of the second air supply cooler 15 in the air supply path 7 between the supercharger 4 and the gas engine 2.

Therefore, the air supply temperature after the first air supply cooler 14 is cooled is higher than the air supply temperature cooled by the second air supply cooler 15. As a result, the temperature of the first cooling water after passing through the first air supply cooler 14 becomes higher than that of the second cooling water after passing through the second air supply cooler 15. In other words, the first cooling water supplied to the first air supply cooler 14 may be at a higher temperature than the second cooling water supplied to the second air supply cooler 15.

Therefore, the first air supply cooler 14 is provided in the return path from the gas engine 2 in the first cooling water path 16 for cooling the gas engine 2. That is, the first air supply cooler 14 cools the supply air by using the first cooling water after cooling the gas engine 2. On the other hand, the second air supply cooler 15 is provided in a second cooling water path 17 separate from the first cooling water path 16 for cooling the gas engine 2. With such a configuration, the cooling type is such that the high temperature supply air at the outlet of the compressor 10 of the supercharger 4 can be secured to the supply air temperature capable of supplying the gas engine.

The air supply cooling device 5 includes a cooling source 18. The cooling source 18 is composed of, for example, a cooling tower or a radiator that cools by utilizing heat of vaporization or the like. The cooling source 18 is connected to the second cooling water path 17, and cools the second cooling water flowing through the second cooling water path 17 by the atmosphere. A pump 19 for circulating the second cooling water is provided in the route from the cooling source 18 to the second air supply cooler 15 in the second cooling water path 17.

Further, in the return path from the second air supply cooler 15 to the cooling source 18 in the second cooling water path 17, heat exchange is performed with the first cooling water path 16 in order to cool the first cooling water. , When the exhaust heat of the first cooling water is not completely recovered by the exhaust heat recovery unit 44 described later, or when the unrecovered exhaust heat remains in the first cooling water, the heat is exchanged with the second cooling water. A heat exchanger 20 is provided at the cooling source 18 to dissipate heat to the atmosphere. Although not shown, a lubrication path through which the lubricating oil flows between the second air supply cooler 15 and the heat exchanger 20 in the second cooling water path 17 in order to cool the lubricating oil of the gas engine 2. A heat exchanger may be provided to exchange heat with the heat exchanger.

A three-way valve 21 for reintroducing a part of the second cooling water flowing through the return path into the going path may be provided between the going path and the returning path in the second cooling water path 17. The temperature of the second cooling water (cooling temperature of the second air supply cooler 15) is adjusted by adjusting the amount of the second cooling water reintroduced by the three-way valve 21. That is, the three-way valve 21 has a function of stabilizing the temperature of the second cooling water supplied to the second air supply cooler 15. When the atmospheric temperature is low, the temperature t _cw of the second cooling water from the cooling source 18 becomes low, but the specified temperature is maintained by the three-way valve 21. A three-way valve 52 is provided on the downstream side of the three-way valve 21 of the second cooling water path 17. _{The three-way valve 52 controls the supply air temperature t 2} by controlling the amount of the second cooling water flowing through the second supply air cooler 15. However, when the air temperature or humidity is high, the temperature t _cw of the second cooling water from the cooling source 18 becomes equal to or higher than the specified temperature, so that the control function of the three-way valve 52 is lost and the second temperature is higher than the specified temperature. The entire amount of cooling water will flow to the second air supply cooler 15.

As described above, the first cooling water flowing through the first air supply cooler 14 is finally required for engine cooling by heat exchange with the heat exchanger 20 and flow control to the heat exchanger 20 by the three-way valve 23. The temperature is adjusted. That is, the excess exhaust heat of the first cooling water obtained by cooling the supply air by the first supply air cooler 14 passes through the second cooling water path 17 as the total amount or the remaining excess exhaust heat after heat recovery. It is indirectly released to the atmosphere by the cooling source 18. A pump 22 for circulating the first cooling water is provided in the route from the heat exchanger 20 to the gas engine 2 in the first cooling water path 16. A three-way valve 51 for reintroducing a part of the first cooling water flowing through the return path into the return path is provided between the going path and the return path in the first cooling water path 16. The three-way valve 51 controls the amount of exhaust heat recovered in the exhaust heat recovery unit 44 by controlling the flow rate flowing to the exhaust heat recovery unit 44, which will be described later.

On the downstream side of the second air supply cooler 15 of the air supply path 7, a supply air temperature detection sensor 24 that detects _{the temperature (supply air temperature) t 2 of the supply air supplied to the gas engine 2 is provided.} .. Controller (not shown) in the charge air cooler 5 (the supply air temperature t ₂ which is detected by the supply air temperature sensor 24 controls the opening of the three-way valve 52 to a predetermined target temperature t _s2.

Thus, charge air cooler 5, executes the control for the air supply temperature t ₂ the target temperature t _s2, for cooling the cooling water by air, the relationship between the atmospheric temperature and the relative humidity, cooling It is almost impossible to cool water below the temperature of the atmosphere. Also, if it is desired to increase the supply air temperature t _2, the three-way valve 52 by controlling the quantity of cooling water flowing through the second charge air cooler 15, it is possible to increase the supply air temperature t _2, Generally, there is an upper limit due to the design limitation of the heat exchanger and the limitation of the control adjustment range of the three-way valve 52. On the other hand, when it is desired to lower the _{supply air temperature t 2 , if the cooling water temperature t cw} from the cooling source 18 is high, even if the three-way valve 52 is bypassed and the entire amount of the second cooling water flows into the second air supply cooler 15. , It is difficult to lower the supply air temperature t _2.

Therefore, the gas engine system 1 in the present embodiment includes an intake air temperature adjusting device 6 that adjusts the intake _{air temperature (intake air temperature) t 1} supplied from the intake air intake introduction unit 8 that takes in the atmosphere to the supercharger 4. .. The intake air temperature adjusting device 6 includes an exhaust heat recovery unit 44, a temperature adjusting device 25, and a controller 26.

The exhaust heat recovery unit 44 recovers the exhaust heat generated by the gas engine 2 and the first air supply cooler 14 as hot water. The exhaust heat recovery unit 44 is provided on the downstream side of the first air supply cooler 14 in the return path of the first cooling water path 16. The exhaust heat recovery unit 44 is configured as a heat exchanger, and recovers the exhaust heat as hot water by exchanging heat with the first cooling water. For example, when cooling the intake air as in the present embodiment, the three-way valve 51 is adjusted so that the entire amount of the first cooling water flows through the exhaust heat recovery unit 44.

Temperature adjuster 25 adjusts the intake air temperature t ₁ with the waste heat recovered by the exhaust heat recovery unit 44. The temperature regulator 25 is a cooling water cooling device 27 that cools cooling water (intake cooling water) for cooling the intake air by using the exhaust heat recovered by the exhaust heat recovery unit 44, and cooling from the cooling water cooling device 27. It includes a cooling pipe 28 that supplies water to the intake air introduction unit 8. The cooling water cooling device 27 is configured as a hot water absorption chiller that cools the cooling water using the hot water recovered by the exhaust heat recovery unit 44.

The cooling water cooling device 27 cools the intake cooling water flowing through the cooling pipe 28 with the heat of vaporization when the first refrigerant (not shown) circulating in the cooling water cooling device evaporates. The first refrigerant that evaporates into water vapor is absorbed by a second refrigerant (not shown) such as lithium bromide. The second refrigerant diluted by absorbing the first refrigerant is heated by using the exhaust heat recovered by the exhaust heat recovery unit 44, and is regenerated to the original concentration. The water vapor generated by separating from the second refrigerant by heating the second refrigerant is cooled by a cooling source (not shown) or the like and condensed as a liquid first refrigerant. With such a hot water absorption chiller, the cooling water that cools the intake air by using the exhaust heat recovery hot water can be easily cooled regardless of the temperature of the atmosphere. A circulation pump that circulates hot water at an appropriate position is interposed in the hot water flow pipe 46 between the exhaust heat recovery unit 44 and the cooling water cooling device 27, but the illustration is omitted in FIG.

The cooling water cooling device 27 may be configured as a steam absorption chiller instead of the hot water absorption chiller as described above. In this case, the exhaust heat recovery device 45 provided in the exhaust gas path 43 is used as an exhaust heat recovery unit for cooling the intake air, and the cooling water cooling device 27 uses the steam recovered by the exhaust heat recovery device 45 to cool water. To manufacture. In this case, the heat exchanger 44 is not required to cool the intake cooling water. The hot water recovered by the heat exchanger 44 may be used as a heat source for district heating or the like.

The cooling pipe 28 through which the intake air cooling water flows is connected to the heat exchanger 30 interposed in the intake path 29 through which the intake air introduced from the intake air introduction unit 8 flows. In the heat exchanger 30, the intake air is cooled by exchanging heat between the intake air cooling water flowing through the cooling pipe 28 and the intake air flowing through the intake air passage 29. The cooling pipe 28 is provided with a circulation pump that circulates the intake cooling water at an appropriate position, but the illustration is omitted in FIG.

The intake cooling water flowing through the heat exchanger 30 is between the going path from the cooling water cooling device 27 to the heat exchanger 30 in the cooling pipe 28 and the return path from the heat exchanger 30 to the cooling water cooling device 27. A three-way valve 31 for adjusting the flow rate may be provided. The temperature of the intake air cooling water (the temperature of the intake air introduced from the intake air introduction unit 8) is adjusted by letting the intake air cooling water escape from the going path to the return path by the three-way valve 31. That is, the three-way valve 31 functions as a temperature adjusting unit of the temperature regulator 25.

The entire amount of cooling water from the cooling water cooling device 27 may be supplied to the heat exchanger 30 without providing the three-way valve 31 as described above. In that case, _{as a method of adjusting the intake air temperature t 1} , the amount of heat exchange in the heat exchanger 30 is indirectly controlled by controlling the temperature of the cooling water supplied from the cooling water cooling device 27 to the heat exchanger 30. You may.

The controller 26 controls the temperature controller 25. Although not shown, the controller 26 is composed of, for example, a computer such as a microprocessor, a memory (storage unit), and / or an electronic circuit. In the intake path 29 (between the heat exchanger 30 and the supercharger 4), an intake air temperature detection sensor 32 for detecting the temperature of the intake air supplied to the supercharger 4 (hereinafter referred to as the intake air temperature) t _{1 is provided.} ing. _{The controller 26 acquires the intake air temperature t 1} from the intake air temperature detection sensor 32, and acquires the temperature of the supply air (hereinafter, supply air temperature) t ₂ supplied from the supply air temperature detection sensor 24 to the gas engine 2.

Controller 26, so that the supply air temperature _{t 2} becomes a predetermined target temperature _{t s2,} controls the intake air temperature _{t 1.} For example, the storage unit, the intake air temperature _{t 1} for the supply air temperature _{t 2} the target temperature _{t s2} of (target temperature _{t s1} of the intake air temperature _{t 1} corresponding to the target temperature _{t s2} of the air supply temperature _{t 2)} The data is stored. Such data is determined by the performance of the supercharger 4 and the performance of the air supply cooling device 5.

The controller 26 reads the acquired data of the intake air temperature t ₁ from charge air temperature t ₂ for the temperature t ₂ the target temperature t _s2 was read-out based on the data, the target value t the intake air temperature t ₁ The opening command value of the three-way valve 31 for setting _{s1 is generated.} The controller 26 transmits a control signal S1 including the generated opening command value to the three-way valve 31 to control the opening of the three-way valve 31. Thus, as the intake air temperature t ₁ is the target value t _s1, the temperature of the intake air cooling water flowing through the heat exchanger 30 that performs heat exchange between the intake air is controlled (feedforward control and feedback control).

_{According to the above configuration, the intake air temperature t 1} supplied to the supercharger 4 is adjusted by the exhaust heat generated in the gas engine 2 that is cooled by using the cooling water cooled by the atmosphere. At this time, the intake air temperature t ₁ is adjusted so that the temperature t ₂ of the air supply to be supplied to the gas engine 2 becomes the predetermined target temperature t _s2. Therefore, it is possible to control the supply air temperature t ₂ regardless of the atmospheric conditions at the target temperature t _s2.

In particular, in the present embodiment, the temperature controller 25 includes a cooling water cooling device 27 for cooling the intake air. This cooling, high temperature atmosphere, where the air supply temperature t ₂ in the charge air cooler 5 alone even if not lowered to the target temperature t _s2, cooled using an exhaust heat by the cooling water cooler 27 it is possible to pre-cool the air by water, it is possible to lower the air supply temperature t ₂ the target temperature t _s2.

FIG. 2 is a diagram showing a schematic graph of the intake air temperature and the supply air temperature with respect to the atmospheric temperature when the control according to the first embodiment is performed. The atmospheric temperature in the graph of FIG. 2 shows an example of the monthly average temperature in the area where the gas engine system 1 is installed in one year. In winter (when the atmospheric temperature is _{less than the reference temperature t c1} and the intake air temperature lower limit value t _{1 min} or more in the turbocharger 4), the control for cooling the intake air as described above is not performed. In this case, the supply air temperature t ₂ is maintained at the target temperature t _s2 by the charge air cooler 5.

When the atmospheric temperature rises in the summer, the temperature of the compressed air supply at the outlet of the supercharger 4 (compressor 10) rises due to the rise in the intake air temperature in the supercharger 4. Furthermore, the increase effect of the second coolant temperature undergoing atmospheric conditions, only supply air cooling device 5 is the supply air temperature t ₂ can not be maintained at the target temperature t _s2. Therefore, if the control for cooling the intake air is not performed, the supply air temperature rises as shown by the broken line in the graph of FIG. Therefore, the second coolant temperature t _cw increases, if the supply air temperature t ₂ have exceeded the target temperature t _s2, the control is performed to cool the intake air by the intake air temperature adjusting device 6. Accordingly, the intake air temperature t ₁ is maintained at a reference temperature t _c1 regardless to ambient temperature, supply air temperature t ₂ is maintained at the target temperature t _s2.

When the air supply temperature passing through the second air supply cooler 15 becomes low due to the intake air cooling, the air supply temperature in the three-way valve 52 even if _{the second cooling water temperature t cw exceeds the reference temperature.} t ₂ will be able to adjust the target temperature _{t s2. In this case, the intake air temperature t 1} may be controlled to be lower by flowing the entire amount of the cooling water supplied from the cooling water cooling device 27 to the heat exchanger 30.

Further, according to the above configuration, the exhaust heat is recovered more efficiently by the cooling water cooling device 27 by setting the recovery point of the exhaust heat as the return path of the first cooling water path 16 in which the hot water recovered by the heat exchange becomes hotter. Since the cooling water can be produced, the intake air temperature t ₁ can be adjusted in a wider temperature range.

Furthermore, according to the above arrangement, by maintaining the supply air temperature t ₂ without being affected by the temperature of the atmosphere by controlling the intake air temperature t ₁ to the target temperature t _s2, the intake air temperature t ₁ be within a predetermined range Can be maintained at. By intake-cooling the air temperature that changes significantly in this way, _{the fluctuation range of the intake air temperature t 1} can be narrowed, so that the air weight flow rate of the intake air that is required to be compressed in the compressor 10 of the supercharger 4 Is the same, but the air volume flow rate compressed in the compressor 10 is reduced. _{Therefore, the width of the intake air temperature t 1} allowed in the turbocharger 4 can be remarkably narrowed as compared with the case where the atmosphere is sucked in as it is. Thus, the compressor blades and the mounting angle of the generic turbocharger 4 is designed to compress the required intake air over a wide inlet air temperature in the conventional, suitable allowable variation width of the intake air temperature t ₁ Since it is possible to specialize in the shape (including specifying the number of compressor blades), it is possible to improve the efficiency of adiabatic compression in the compressor 10 of the turbocharger 4.

Further, according to the above configuration, if the supply air temperature t ₂ is stabilized at the target temperature t _s2 regardless of the atmospheric temperature, the mixing ratio of the supply air and the fuel is stabilized, and as a result, the combustion in the gas engine 2 is performed. Is performed in the optimum state, so that the gas temperature t ₃ after combustion from the gas engine 2 is also stabilized, and the fluctuation range is _{narrower than that when the supply air temperature t 2} fluctuates greatly according to the change in the atmospheric temperature. Become. Therefore, instead of the conventional general-purpose turbocharger, which was designed to expand the gas after combustion in a wide high temperature range with an emphasis on versatility and generate power, the turbine blades of the turbocharger 4 are used. the temperature range of the burned gas temperature t ₃ and narrower than a general-purpose machine, by the maximum efficiency narrowed down operation range to a narrower range shape (including a specific number of turbine blades), turbocharger 4 It is possible to improve the efficiency of the turbine 11 in the normal operating range. By improving the efficiency of the turbine 11 of the supercharger 4 in this way, the performance of the gas engine 2 can be improved.

Further, in the present embodiment, the cooling pipe 28 is provided with an on-off valve 33. Further, an on-off valve 34 is also provided in the pipe between the exhaust heat recovery unit 44 and the cooling water cooling device 27. These on-off valves 33 and 34 are closed when the intake air does not need to be cooled, and the flow of fluid (cooling water or the like) in each pipe is blocked.

For example, in the area where the gas engine system 1 is laid, the supply air temperature t ₂ can be maintained at the target temperature t _s only by cooling the supply air by the air in the supply air cooling device 5 in winter, while the supply air is supplied in summer. In areas where the intake air needs to be cooled because it cannot be maintained only by cooling in the cooling device 5, the on-off valves 33 and 34 open in the summer to allow fluid to flow, while in the winter, the on-off valves are allowed to flow. The valves 33 and 34 are closed to disable the flow of fluid. As a result, in winter, the excess exhaust heat can be recovered by the exhaust heat recovery unit 44 and used for other purposes such as heating the building. In FIG. 1, the piping for sending the hot water recovered by the waste heat recovery unit 44 to the outside is not shown.

The controller 26 is configured to be able to transmit a switching signal S2 for switching the opening / closing of the on-off valves 33 and 34 to the on-off valves 33 and 34. The switching signal S2 may be generated based on the operation input of the operator. Alternatively, the switching signal S2 may be automatically generated by the controller 26 based on a set time. Alternatively, the controller 26 may acquire the outside air temperature, and the controller 26 may automatically generate the outside air temperature based on the acquired outside air temperature.

Instead of switching the on-off valves 33 and 34 by the controller 26, the facility worker may directly open and close the on-off valves 33 and 34. Further, for example, when the intake air is cooled all year round, the on-off valves 33 and 34 may not be provided.

The target temperature _{t s2} of the air supply temperature _{t 2,} the property of the fuel gas (e.g., methane number _{F MN} or heat _{F CAL,} etc.) may be set to a different value depending on. Figure 3 is a graph showing an example of a relationship between the target temperature t _s2 supply air temperature t ₂ for methane number F _MN of the fuel gas. In FIG. 3, the high-low relationship _{of the methane value F MN of the fuel gas is F MN0} <F _MN1 << ... <F _MN5 . As shown in FIG. 3, the target temperature t _s2 of the air supply temperature t _2, the methane number F _MN of the fuel gas is set higher as the target temperature t _s2 of the air supply temperature t ₂ becomes high. In the example of FIG. 3, the methane value F _MN is divided into a plurality of stages (5 stages), and different target temperatures t _{s2-0 to t s2-4} are set according to each stage. Incidentally, methane number F _MN classified more finely to the to the number of may set the target temperature t _s2 accordingly, methane number F target temperature classification coarser to the number of corresponding to that of _MN t _s2 May be set. Further, in the example of FIG. 3, the _{stages of the methane value F MN} are set at equal intervals, but they may be set at arbitrary intervals (intervals different from each other).

The range of the methane values F _{MN1 to} F _MN5 in FIG. 3 is the range in which the gas engine 2 can operate at the rated value. In the example of FIG. 3, in _{the control of the intake air temperature t 1} , the range of the methane value that can be operated at the rated value is set to four stages (F _{MN1 to} F _MN2 : 1st stage, F _{MN2 to} F _MN3 : 2nd stage, F. _MN3 to F _MN4: third _step, F MN4 _{to F MN5:} divided into stage 4), and sets the target temperature _t S2-1 _{~t S2-4} of the supply temperature _{t 2} corresponding to each. The methane value F _MN0 is a lower limit value that can be used as a fuel for the gas engine 2. The range of methane value F _{MN0 to} F _MN1 (stage 0) is a range that can be operated by reducing the output of the gas engine 2. _{The intake air temperature t 1} may be controlled even during operation in a state where the output of the gas engine 2 is reduced. The target temperature of the supply air temperature t ₂ at this time is set to _{t s2-0.} Further, the methane value F _MN5 or higher is a region in which the gas engine 2 cannot be operated because the calorific value of the fuel gas is too low. The methane value F _MN is calculated in a timely manner from the value of the gas composition of the fuel gas.

FIG. 4 is a graph showing an example of the relationship between the target temperature t s _2'of the supply air temperature t _{2 with respect to the calorific value F CAL of the fuel gas.} 4, a relationship among the amount of heat _{F CAL} fuel gas _{is F CAL0 <F CAL1 <... <} F CAL5. There is a certain degree of correlation between the methane value F _MN of the fuel gas and the calorie F _{CAL of the fuel gas.} That is, the _{higher the calorie F CAL of the} fuel gas, the lower the methane value F _MN. Each heat _{F CAL0,} F CAL1 in FIG 4, _{..., F CAL5} is methane number _{F MN5,} F MN4 respectively, in FIG 3, _..., is almost equivalent to the values in _{F MN0.}

Accordingly, as shown in FIG. 4, the target temperature t _{s2 ',} the target temperature t _s2 of the higher heat F _CAL fuel gas supply temperature t _2' inlet air temperature t ₂ is set to be lower May be good. In the example of FIG. 4, as in the case of methane number _{F MN} shown in FIG. 3, a plurality of stages the amount of heat _{F CAL} (5 _{out: F CAL0 ~F CAL1, F cal1} ~F cal2, F cal2 ~F cal3, F _It is divided into cal3 to F _cal4 and F _{cal4 to F cal5} ), and different target temperatures t _{s2-0'to t s2-4} ' are set according to each stage. The target temperature t s2'may be set by making the classification of the calorific value F _{CAL of the fuel gas finer and setting the target temperature t s2'correspondingly,} or by making the classification of the calorific value F _CAL of the fuel gas coarser and correspondingly. The target temperature t _s2'may be set. Further, in the example of FIG. 4, _{each stage of the calorific value FCAL} of the fuel gas is set at equal intervals, but it may be set at arbitrary intervals (intervals different from each other).

In the gas engine 2, the air-fuel ratio that can be operated at the highest efficiency point is determined by _{the methane value F MN} or the calorie F _{CAL of the fuel gas.} Therefore, the operation of the air supply temperature _{t 2,} by controlling so that the target temperature _{t s2} or _{t s2} 'suitable for methane number _{F MN} or heat _{F CAL} fuel gas, at the highest efficiency point of the gas engine 2 Is possible. In the case where the property of the fuel gas is not input to the controller 26, the supply air temperature _t as a target temperature _{t s2 or} t _s2 'of _2, the target temperature _{t S2o (e.g. t S2-2} or _{t s2} predetermined _It may be set to (a value equal to -2').

Incidentally, the target temperature _{t s2} corresponding to methane number _{F MN,} the target temperature _{t s2} 'corresponding to the amount of heat _{F CAL} are different. When both of these target temperatures t _s2 and t _s2'are used, the target temperature t _s2 corresponding to the methane value F _MN is set as the main target temperature, and when _{the information on the methane value F MN} cannot be obtained, the calorific value F _CAL is used. It may be controlled by using the target temperature t _s2'.

[Modification example]
In the embodiment, as to get the controller 26 the temperature t ₂ of the supply air supplied from the supply air temperature detection sensor 24 to the gas engine 2, the temperature t ₂ is obtained becomes a predetermined target temperature t _s2 An embodiment in which the intake air temperature t ₁ is controlled has been illustrated. Alternatively, the controller 26, as to get the temperature t ₃ post-combustion gas exhausted from the gas engine 2, the temperature t ₃ when the acquired becomes a predetermined target temperature t _s3, the intake air temperature t ₁ You may control it. The post-combustion gas temperature t ₃ is detected by the post-combustion gas temperature detection sensor 39 provided in the exhaust path 12.

The properties of the fuel supplied to the gas engine 2 and the post-combustion gas temperature t ₃ have a correlation with the supply air temperature t _2. In other words, properties of the fuel is stable if the variation is small, by controlling so that burned gas temperature t ₃ becomes a predetermined target temperature t _s3, is maintained substantially at the target temperature t _s2 also supply air temperature t ₂ It can be said that. Therefore, even by post-combustion gas temperature t ₃ in place of the air supply temperature t ₂ controls the intake air temperature t ₁ so that the target temperature t _s3, the same effect as in the case of obtaining a supply air temperature t ₂ Play.

When the gas temperature t ₃ after combustion is acquired and the intake air temperature t _{1 is controlled, the target temperature t s 3 may} be set and changeable according to the properties of the fuel gas supplied to the gas engine 2. When the signals of both the supply air temperature detection sensor 24 and the post-combustion gas temperature detection sensor 39 are acquired and controlled, if the operation is performed during the period when one of the temperature detection sensors fails, the other temperature detection sensor The operation may be continued with only the signal. Further, the controller 26 _{acquires both the supply air temperature t 2} and the post-combustion gas temperature t _3, and monitors the operating state of the gas engine 2 by comparing the target temperatures at which the respective temperatures are set. You may go.

Further, in the first embodiment, the air supply cooling device 5 includes a cooling source 18 for the first air supply cooler 14 and the second air supply cooler 15, and one cooling source 18 to the second cooling water. Was supplied to the second air supply cooler 15, and the second cooling water discharged from the second air supply cooler 15 removed necessary heat from the first cooling water having a higher temperature. That is, in the first embodiment, the second cooling water is directly cooled by the cooling source 18 in the second air supply cooler 15, while the first cooling water is cooled in the second cooling water path 17 and the first cooling. It is indirectly cooled via a heat exchanger 20 that exchanges heat with the water path 16.

The mode of the air supply cooling device 5 is not limited to the mode of the first embodiment. For example, a heat exchanger (for example, a radiator) that dissipates heat from the hot water to the atmosphere due to the temperature difference between the atmospheric air and the hot water may be used as the cooling source. FIG. 5 is a diagram showing a schematic configuration of a gas engine system 1A according to a modification 1 of the first embodiment of the present invention. In FIG. 5, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. FIG. 5 shows an example in which two radiators 35 and 36 are provided as heat exchangers.

The air supply cooling device 5A in this modification includes radiators 35 and 36 that individually cool the first cooling water and the second cooling water flowing through the two air supply coolers 14 and 15, respectively. The first radiator 35 is connected to the first cooling water path 16A and supplies the first cooling water to the first air supply cooler 14 via the gas engine 2 to supply air to the outlet of the supercharger 4. To cool. The second radiator 36 is connected to the second cooling water path 17A and supplies the second cooling water to the second air supply cooler 15 to cool the supply air discharged from the first air supply cooler 14. The first cooling water path 16A and the second cooling water path 17A are configured independently of each other (non-heat exchangeable). The cooling capacity of the radiators 35 and 36 is such that the first cooling water dissipates the heat recovered by the gas engine 2 and the first air supply cooler 14 to the atmosphere, and the second cooling water dissipates the heat recovered by the second air supply cooler 15 and oil (not shown). The heat recovered by the cooler or the like is dissipated to the atmosphere, and each is designed to have a capacity that allows the gas engine system to operate without problems.

The first cooling water path 16A circulates the first cooling water from the first radiator 35 to the first air supply cooler 14 via the gas engine 2. A three-way valve 23A for adjusting the temperature of the first cooling water by reintroducing a part of the first cooling water flowing through the return path between the going path and the returning path in the first cooling water path 16A into the going path. Is provided. Similar to the first embodiment, an exhaust heat recovery unit 44 is provided between the first air supply cooler 14 and the three-way valve 23A. The three-way valve 51 adjusts the amount of heat recovered by the exhaust heat recovery unit 44.

The second cooling water path 17A circulates the second cooling water from the second radiator 36 to the second air supply cooler 15. A three-way valve 21A for adjusting the temperature of the second cooling water by reintroducing a part of the second cooling water flowing through the return path between the going path and the returning path in the second cooling water path 17A into the going path. , 52 are provided. The three-way valve 52 controls the amount of cooling water flowing through the second charge air cooler 15, adjusted to supply air temperature t ₂ becomes the target temperature t _s2.

In this way, even for the gas engine system 1A in which the air supply cooling device 5A is composed of two radiators 35 and 36 and the two cooling water paths 16A and 17A are independent, the exhaust heat is recovered from the waste heat recovery unit 44. The intake air temperature adjusting device 6 that cools the intake air by using heat can be applied in the same manner as in the first embodiment.

In the modified examples shown in the first embodiment (FIG. 1) and FIG. 5, the supercharger 4 uses the cooling water after the first air supply cooler 14 has cooled the gas engine 2 in the first cooling water path 16. An embodiment of cooling the supply air at the outlet of the above is illustrated. Instead of this, cooling water is supplied to the first air supply cooler from the cooling source 18 or the heat exchanger (radiator 36) without passing through the cooling path of the gas engine 2 in the same manner as the second air supply cooler. It may be configured as follows.

FIG. 6 is a diagram showing a schematic configuration of the gas engine system 1F according to the second modification of the first embodiment of the present invention. In FIG. 6, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. The air supply cooling device 5F in this modification cools the air supply cooling cooling water path 56F that supplies cooling water to each of the first air supply cooler 14F and the second air supply cooler 15F, and the gas engine 2. Therefore, a gas engine cooling path 54F provided separately from the supply air cooling cooling water path 56F is provided.

In this modification, the air supply cooling cooling water path 56F is a first cooling water path 16F that supplies cooling water from the cooling source 18 to the first air supply cooler 14F, and cooling water from the cooling source 18 is the first. 2 Includes a second cooling water path 17F supplied to the air supply cooler 15F. The first cooling water path 16F and the second cooling water path 17F are provided in parallel. A third cooling water path 53F is connected to the cooling source 18, and the first cooling water path 16F and the second cooling water path 17F are branched from the third cooling water path 53F.

A heat exchanger 20 that exchanges heat with the gas engine cooling path 54F that cools the gas engine 2 is provided in the return path of the third cooling water path 53F. The exhaust heat recovery unit 44 is provided on the downstream side of the gas engine 2 in the gas engine cooling path 54F, and recovers the exhaust heat generated by the gas engine 2 as hot water. That is, in this modification, the high-temperature cooling water after cooling the gas engine 2 is recovered to the atmosphere by the exhaust heat recovery unit 44 and the heat exchanger 20 without passing through the first air supply cooler 14F. Is dissipated.

Also in this modification, the three-way valve 51 adjusts the amount of heat recovered by the exhaust heat recovery unit 44. Further, the three-way valve 52 controls the amount of cooling water flowing through the second charge air cooler 15, adjusted to supply air temperature t ₂ becomes the target temperature t _s2. Even in such a configuration, similarly to the gas engine system 1 shown in FIG. 1, it is possible to control the supply air temperature t ₂ regardless of the atmospheric conditions at the target temperature t _s2.

According to the above configuration, the supply air cooling cooling water path 56F for cooling the supply air and the gas engine cooling path 54F for cooling the gas engine 2 are configured as different paths, and therefore, in the example of FIG. _{As described above, the intake air temperature t 1} is lower than that in the case where the first air supply cooler is provided on the downstream side of the cooling path of the gas engine 2 (first cooling water path 16 in FIG. 1), and as a result, it is excessive. it is easy to intake air temperature at the outlet of the compressor 10 of the turbocharger 4 is controlled supply air temperature t _2, even when it becomes lower the target temperature t _{s2. Therefore, the supply air temperature t 2} can be adjusted by the first air supply cooler 14F and the second air supply cooler 15F in a wider temperature range.

FIG. 7 is a diagram showing a schematic configuration of a gas engine system 1G according to a modification 3 of the first embodiment of the present invention. In FIG. 7, the same components as those in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted. The air supply cooling device 5G in this modified example includes two radiators 35 and 36 as heat exchangers, as in the example of FIG.

Further, the air supply cooling device 5G in the present modification is the air supply cooling cooling water that supplies cooling water to each of the first air supply cooler 14G and the second air supply cooler 15G, as in the example of FIG. It includes a path 56G and a gas engine cooling path 54G provided separately from the supply air cooling cooling water path 56G for cooling the gas engine 2.

The air supply cooling cooling water path 56G in this modification is the first cooling water path 16G that supplies the cooling water from the second radiator 36 to the first air supply cooler 14G, and the cooling water from the second radiator 36. It includes a second cooling water path 17G supplied to the second air supply cooler 15G. The first cooling water path 16G and the second cooling water path 17G are provided in parallel. A third cooling water path 53G is connected to the second radiator 36, and the first cooling water path 16G and the second cooling water path 17G are branched from the third cooling water path 53G.

A gas engine cooling path 54G for cooling the gas engine 2 is connected to the first radiator 35. The exhaust heat recovery unit 44 is provided on the downstream side of the gas engine 2 in the gas engine cooling path 54G, and recovers the exhaust heat generated by the gas engine 2 as hot water. That is, in this modification, the high-temperature cooling water after cooling the gas engine 2 is recovered to the atmosphere by the exhaust heat recovery unit 44 and the first radiator 35 without passing through the first air supply cooler 14F. Is dissipated.

Also in this modification, the three-way valve 51 adjusts the amount of heat recovered by the exhaust heat recovery unit 44. Further, the three-way valve 52 controls the amount of cooling water flowing through the second charge air cooler 15, adjusted to supply air temperature t ₂ becomes the target temperature t _s2. Even in such a configuration, similarly to the gas engine system 1A shown in FIG. 5, it is possible to control the supply air temperature t ₂ regardless of the atmospheric conditions at the target temperature t _s2.

According to the above configuration, the supply air cooling cooling water path 56G for cooling the supply air and the gas engine cooling path 54G for cooling the gas engine 2 are configured as separate paths, and therefore, in the example of FIG. _{As described above, the intake air temperature t 1} is lower than that in the case where the first air supply cooler is provided on the downstream side of the cooling path of the gas engine 2 (first cooling water path 16A in FIG. 5), and as a result, it is excessive. it is easy to intake air temperature at the outlet of the compressor 10 of the turbocharger 4 is controlled supply air temperature t _2, even when it becomes lower the target temperature t _{s2. Therefore, the supply air temperature t 2} can be adjusted by the first air supply cooler 14G and the second air supply cooler 15G in a wider temperature range.

[Embodiment 2]
Next, Embodiment 2 of the present invention will be described. FIG. 8 is a block diagram showing a schematic configuration of the gas engine system 1B according to the second embodiment of the present invention. In FIG. 8, the same components as those in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted. Gas engine system 1B is different from the first embodiment in the present embodiment, in addition to the function of cooling the intake air temperature t ₁ at a temperature regulator 25B of the intake air temperature adjusting device 6B, function of heating the intake air temperature t ₁ Is to have. Further, the gas engine system 1B in the present embodiment includes radiators 35 and 36 as heat exchangers of the air supply cooling device 5A, as in the configuration shown in FIG.

More specifically, the temperature controller 25B includes a heating pipe 37 and a pipe switching portion in addition to the cooling water cooling device 27 and the cooling pipe 28.

The heating pipe 37 supplies the hot water from the exhaust heat recovery unit 44 to the heat exchanger 30 provided in the intake air introduction unit 8 in order to heat the intake air. That is, the heating pipe 37 is configured as a bypass path for the cooling water cooling device 27 between the exhaust heat recovery unit 44 and the heat exchanger 30 (and the three-way valve 31) in the cooling pipe 28.

As for the exhaust heat recovery amount of the exhaust heat recovery unit 44, the maximum amount may be recovered when hot water is recovered by the cooling water cooling device 27 (when intake air cooling is performed). On the other hand, when the intake air is heated, the amount of hot water required for heating is smaller than that at the time of intake air cooling because the temperature of the hot water is high. Therefore, by controlling the amount of the first cooling water flowing to the exhaust heat recovery unit 44 by the three-way valve 51, the temperature of the hot water used at the time of intake heating is lowered, and the hot water is supplied to the heat exchanger 30. , Perform intake air heating.

The pipe switching unit switches the pipe connected to the intake air introduction unit 8 (heat exchanger 30 in the heat exchanger 30) between the cooling pipe 28 and the heating pipe 37. The pipe switching unit includes the on-off valves 33 and 34 described in the first embodiment and the on-off valve 38 provided in the heating pipe 37. Similar to the first embodiment, the on-off valves 33 and 34 are controlled to open and close by the controller 26. The on-off valve 38 is also controlled to open and close by the controller 26.

When the pipe connected to the intake air introduction portion 8 is a cooling pipe 28, the on-off valves 33 and 34 are opened and the on-off valve 38 is closed. On the other hand, when the pipe connected to the intake intake introduction portion 8 is a heating pipe 37, the on-off valves 33 and 34 are closed and the on-off valve 38 is opened.

For example, the controller 26 outputs a signal including a first value (high) and a second value (low) as a switching signal S2 to be sent to the on-off valves 33, 34, and 38. The on-off valves 33 and 34 open when the first value switching signal S2 is received, and close when the second value switching signal S2 is received. On the other hand, the on-off valve 38 closes when it receives the first value switching signal S2 and opens when it receives the second value switching signal S2. Instead of this, the switching signal for the on-off valves 33 and 34 and the switching signal for the on-off valve 38 may be different signals.

When the on-off valves 33 and 34 are opened and the on-off valve 38 is closed, the intake air cooling water is supplied to the intake air introduction unit 8 and the intake air is cooled as in the first embodiment. On the other hand, when the on-off valves 33 and 34 are closed and the on-off valve 38 is opened, the hot water flowing through the heating pipe 37 is supplied to the intake intake section 8 as it is by the exhaust heat recovered from the exhaust heat recovery section 44. And the intake air is heated. Since the amount of exhaust heat recovered by the exhaust heat recovery unit 44 is controlled by the three-way valve 51 as described above, the switching signal S2 from the controller 26 is also transmitted to the three-way valve 51.

Also in this embodiment, the controller 26, such that the supply air temperature t ₂ which is supplied to the gas engine 2 reaches the predetermined target temperature t _s2, controls the intake air temperature t _{1. The target temperature t s2} can take different values between the time of intake air cooling and the time of intake air heating. In this case, the target temperature of the supply air temperature t ₂ during the intake cooled to t _sc2, when the target temperature of the supply air temperature t ₂ during the intake heating and t _sh2, the storage unit, the sheet in the case of cooling the intake air in addition to the data of the intake air temperature _{t 1} of the target temperature _{t sc1} corresponding to the target temperature _{t sc2} of air temperature _{t 2,} it is the data of the intake air temperature _{t sh1} corresponding to the target temperature _{t sh2} is stored in the case of heating the intake There is. However, in the power generation efficiency priority mode described later, the apparent target temperature t _sh2 of the supply air temperature t ₂ used for setting the target temperature t _{s1 of the intake air temperature t 1} at the time of intake air heating is the target temperature at the time of intake air cooling. It may be set to the same temperature as _{t sc2 or a higher temperature.}

Also in this embodiment, as described in the first embodiment, the target temperature t _sh2 at the target temperature t _sc2 and intake air heating during the intake cooling, the properties of the fuel gas is inputted to the controller 26 In the case, the value is set according to the input property of the fuel gas. Further, when the property of the fuel gas is not input to the controller 26, as the target temperature t _s2 of the air supply temperature t _2, may be set to a predetermined value.

At the time of intake air heating, the amount of hot water heat required for intake air heating differs depending on the atmosphere temperature. Therefore, the controller 26 also transmits a control signal to the three-way valve 51 in order to control the _{intake air temperature t 1, and the intake air temperature is changed from the atmosphere temperature to the intake air temperature.} sufficient heat recovery amount to achieve the target temperature t _sc1 of t ₁ is controlled so as to obtain in the exhaust heat recovery unit 44.

The controller 26 reads out the data of the target temperature t _sc1 of the intake air temperature t _{1 for setting the supply air temperature t 2} to the target temperature t sc 2 at the time of intake air cooling, and performs feedforward control and feedback control. The controller 26 controls the amount of cooling water required _{to set the intake temperature t 1} to the target temperature t _sc 1 from the air temperature, humidity, and the amount of air stored as data in advance as the intake amount of the gas engine 2 as feed forward control. Is calculated, and control is performed to transmit the information to the three-way valve 31. Further, as feedback control, the controller 26 finely adjusts the amount of cooling water flowing through the heat exchanger 30 by the three-way valve 31 based on the data of the _{intake air temperature t 1} and the supply air temperature t _{2 obtained as a result of the feedforward control.} I do.

Further, the controller 26 reads out the data of the intake air temperature t _{sh1 for setting the supply air temperature t 2} to the target temperature t _sh2 at the time of intake air heating, and performs feedforward control and feedback control. As feed-forward control, the controller 26 calculates the heating amount required _{to set the intake air temperature to the target value t sh1} from the air amount stored as data in advance as the air temperature, humidity, and the intake amount of the gas engine 2. Then, control is performed to transmit the information to the three-way valve 31. Further, as feedback control, the controller 26 adjusts the hot water flow rate to the exhaust heat recovery unit 44 by the three-way valve 51 based on the data of the _{intake air temperature t 1} and the supply air temperature t _{2 obtained as a result of the feedforward control.} , The amount of hot water flowing through the heat exchanger 30 is finely adjusted by the three-way valve 31.

_{However, the target temperature t sh2} at the time of intake air heating determines the apparent target temperature of the corresponding supply air temperature t _{2 in} the controller 26 in order to raise the intake air temperature t _{1 to the last, and the actual supply} The air temperature t ₂ is controlled by the air supply cooling device 5A _{so as to be the same as the target temperature t sc2} at the time of intake cooling (power generation efficiency priority mode).

If the underlying target temperature _{t s1} of the intake air temperature _{t 1} supply air temperature _{t 2} of the apparent target temperature _{t sh2} becomes a value different from the target temperature _{t sc2} supply air temperature _{t 2} in the charge air cooler 5A There is a possibility that the control _{of the intake air temperature t 1 in} the controller 26 of the intake air temperature adjusting device 6 and the control _{of the supply air temperature t 2 in} the controller (not shown) of the supply air cooling device 5 interfere with each other. _{In such a case, the control responsiveness of the supply air temperature t 2} controlled by the supply air cooling device 5 may be slower than the control responsiveness of the _{intake air temperature t 1} controlled by the intake air temperature adjusting device 6. ..

In this case, the control in the intake air temperature adjusting device 6 (control for three-way valve 31), the intake air temperature t ₁ is controlled so that the supply air temperature t ₂ becomes the target temperature t _sh2 apparent, then, the charge air cooler 5 By the control in (control over the three-way valve 52), the supply air temperature t ₂ is controlled to be the final target temperature t _sc2.

According to the above configuration, the heat exchanger 30 can be used as an intake air cooler by the cooling water produced by using the exhaust heat of the air supply cooling device 5A in the cooling water cooling device 27. As a result, even if the air temperature is high such as in summer and the air supply cooling device 5 _{cannot lower the supply air temperature t 2 to the target temperature t sc2} at the time of intake air cooling, the supply air temperature t ₂ is intake cooled. The target temperature at time can be lowered to _{t sc2.}

Further, the pipe connected to the intake air introduction unit 8 is configured to be switchable between the cooling pipe 28 through which the cooling water flows and the heating pipe 37 through which the hot water flows. As a result, the heat exchanger 30 can be used as an intake air heater, so that the intake air temperature can be raised.

Since the compressor 10 of the turbocharger 4 is designed as a general-purpose product, a lower limit value is set for the intake air temperature as a design limit. Therefore, when the atmospheric temperature is low, such as in winter, the operation cannot be performed unless the intake air temperature becomes equal to or higher than the lower limit due to the design limitation of the compressor 10 of the turbocharger 4. Conventionally, in order to continue operation even in such a case, both an outside air intake facility that introduces outside air as intake air and an indoor intake facility that introduces indoor air as intake air are prepared, and the atmosphere. When the temperature becomes low, it is necessary to install complicated mechanical equipment such as switching from the outside air intake by the outside air intake equipment to the indoor intake by the indoor intake equipment, or it is necessary to use only the indoor intake equipment from the beginning. When indoor intake is performed throughout the year, the indoor temperature is higher than the outside air temperature in summer, so it is difficult to always operate at an air-fuel ratio close to the optimum, and high-efficiency operation cannot be expected throughout the year.

On the other hand, according to the present embodiment, even when the temperature of the atmosphere becomes low and it becomes necessary to raise the intake air temperature due to the design limitation of the compressor 10 of the supercharger 4, the air intake to the room It is possible to raise the intake air temperature without using complicated mechanical equipment to switch to intake air or performing indoor intake air throughout the year. Accordingly, while securing design limitation of the compressor 10 of the turbocharger 4, a supply air temperature t ₂ can be controlled to the target temperature t _s2.

Also, in winter, more heat may be required for district heating and the like. The heat supply source is an exhaust heat recovery unit 45 provided in the exhaust heat recovery unit 44 and the exhaust gas path 43. The amount of heat recovered in the exhaust heat recovery device 45 increases as the _{exhaust gas temperature t 4 at the outlet of the turbine 11 of the turbocharger 4 increases.}

In order to increase the heat recovery amount in the exhaust heat recovery device 45, controller 26, the target temperature of the air supply temperature t ₂ is the target temperature for the high power generation efficiency in the power generation efficiency priority mode (first control mode) Instead of (first target temperature), it is possible to execute a heat recovery priority mode (second control mode) set to a target temperature (second target temperature) for increasing the amount of heat recovery.

In the following, the target temperature _{of the supply air temperature t 2} in the power generation efficiency priority mode _{is t sq2,} and the target temperature of the supply air temperature t 2 in the heat recovery priority mode is t _{sr 2} . Target temperature t _sq2 in the power generation efficiency priority mode is a concept including a target temperature t _sh2 at the target temperature t _sc2 and intake air heating during the above-described intake-air cooling. That is, when the properties of the fuel gas are input to the controller 26, the _{target temperature t sq2} in the power generation efficiency priority mode is set to a value corresponding to the input properties of the fuel gas. When the properties of the fuel gas are not input to the controller 26, the target temperature t _sq2 in the power generation efficiency priority mode may be set to a predetermined value. In the following, the target temperature t _sq2 in the power generation efficiency priority mode will be illustrated as a case where the target temperature t sq2 is a constant value throughout the year regardless of whether the intake air is cooled or the intake air is heated. _{The target temperature t sr2} in the heat recovery priority mode is set to a temperature higher than the _{target temperature t sq2} in the power generation efficiency priority mode.

_{The target temperature t sr2} in the heat recovery priority mode may be set to a constant value regardless of the properties of the fuel gas. _{Alternatively, t sr2} in the heat recovery priority mode may be set to a different value depending on the properties of the fuel gas.

Figure 9 is a graph showing an example of a relationship between the target temperature _{t sq2, t sr2} air supply temperature _{t 2} corresponding to the priority mode for methane number _{F MN} of the fuel gas. The setting mode of the target temperature t _{sq2 of the supply air temperature t 2} in the power generation efficiency priority mode is the same as the example of FIG. That is, the target temperature _{t sq2-0 ~t sq2-4} each stage (0th stage to fourth stage) in FIG. 9, the target temperature _t of each step in FIG. 3 (zeroth stage to fourth stage) _s2- Corresponds to _{0 to t s2-4.}

Target temperature t _sr2 in the heat recovery priority mode, a high value relative to the target temperature t _sq2 in the power generation efficiency priority mode. That is, the target temperature set in each stage of the heat recovery priority mode (0th to 4th stages) is higher than the target temperature set in each stage of the power generation efficiency priority mode.

Further, in the example of FIG. 9, the target temperature t _sr2 in the heat recovery priority mode has the same target temperature (t _sr2- ) in the 0th stage (F _{MN0 to} F _MN1 ) and the 1st stage (F _{MN1 to} F _{MN2). 1} ), and the target temperatures in the third stage (F _{MN2 to} F _MN3 ) and the fourth stage (F _{MN3 to} F _MN4 ) are set to the same value ( _tsr2-3 ). The target temperature in the second stage (F _{MN1 to} F _{MN2 ) is t sr2-2} . That is, in the heat recovery priority mode, the methane value F _MN is divided into three coarser stages than the power generation efficiency priority mode, and different target temperatures t _{sr2-1 to t sr2-3} are set according to each stage.

Although the example of FIG. 9 shows an example in which the heat recovery priority mode is divided more coarsely than the power generation efficiency priority mode, the same division method (for example, 5 stages) is used between the power generation efficiency priority mode and the heat recovery priority mode. Alternatively, the heat recovery priority mode may be divided more finely than the power generation efficiency priority mode. Further, in the example of FIG. 9, the combined methane-valent threshold _{F MN2, F MN3} methane number threshold _{F MN2, F MN3} switching the target temperature _{t sr2} differ in heat recovery priority mode in the power generation efficiency priority mode is set Te, but the value may be different from the different target temperatures _t methane number of the threshold _F MN2 switch to _{sr2, F MN3} methane number of the values _F MN2 in the power generation efficiency priority _{mode, F MN3.} For example, the second step in the heat recovery priority mode may be a range from a value smaller than _{F MN2 to a value larger than F MN3} , and the second step may be a wider range of methane value.

Depending on the amount of heat _{F CAL} fuel gas is also true for setting target temperature _{t sr2} different. FIG. 10 is a graph showing an example of the relationship between the target temperature t s _{2'of the supply air temperature t 2} according to each priority mode with respect to _{the calorific value F CAL of the fuel gas.} Manner of setting the target temperature t _{sq2 'of} supply air temperature t ₂ in the power generation efficiency priority mode is similar to the example of FIG. That is, the target temperature t of the steps in FIG. 10 the target temperature _{t sq2-0 '~t sq2-4'} of (0th stage to fourth stage), each stage in FIG. 4 (zeroth stage to fourth stage) corresponding to the _{s2-0 '~t s2-4'.}

Target temperature t _sr2 in the heat recovery priority mode _', the target temperature t _sq2 in the power generation efficiency priority _mode' a higher value for. That is, the target temperature set in each stage of the heat recovery priority mode (0th to 4th stages) is higher than the target temperature set in each stage of the power generation efficiency priority mode. Further, in the example of FIG. 10, as in the example of FIG. 9, in the heat recovery priority mode, the amount of heat F _CAL the three stages rougher than the power generation efficiency priority mode, the target temperature t varies in accordance with each stage _sr2-1 ' _{~ t sr2-3} ' is set.

In the heat recovery priority mode, as the supply air temperature t ₂ becomes the target temperature t _sq2 higher target temperature t _sr2 in the power generation efficiency priority mode, the intake air temperature t ₁ is controlled to be heated, the second cooling water The three-way valve 52 in the path 17A adjusts the amount of cooling water flowing through the second air supply cooler 15. Therefore, the gas temperature t ₃ rises after combustion, and the exhaust gas temperature t ₄ also rises. Therefore, the amount of heat recovered in the exhaust heat recovery device 45 provided in the exhaust gas path 43 increases. Since the target temperature of the air supply temperature t ₂ is controlled to a temperature higher than the target temperature t _s2 for high power generation efficiency, the power generation efficiency is reduced. On the other hand, in order to keep the amount of power generation constant, the amount of increase in the amount of exhaust heat recovered by the exhaust heat recovery unit 44 is larger than the amount of increase in fuel to the gas engine 2 that increases as the power generation efficiency decreases. Therefore, the power generation efficiency itself is lowered, but the total thermal efficiency of the entire system is improved. In this specification, the total thermal efficiency is defined as follows.

Total thermal efficiency [%] = {(generator end output + amount of heat recovered from exhaust heat) / (amount of fuel input to gas engine 2)} x 100

_{When the supply air temperature t 2} can be maintained at the target temperature t _s only by cooling the supply air by the atmosphere in the supply air cooling device 5 such as in spring or autumn, all the on-off valves 33, 34, and 38 are closed. The flow of fluid in the cooling pipe 28 and the heating pipe 37 may be disabled. Moreover, even in such a case, while the intake air temperature t ₁ the controller 26 can be achieved when using the cooling water of the cooling water cooling system 27 from the ambient temperature to a target value t _s1, by adjusting the three-way valve 52, the supply air temperature _{t 2} may be adjusted to the target temperature _{t s2.} As a result, the work load of the compressor 10 of the supercharger 4 is reduced, so that the power generation efficiency can be improved. In this way, the intake air temperature t ₁ can be controlled in a wide range _{for the optimum supply air temperature t 2} in response to various changes in the outside air temperature.

FIG. 11 is a diagram showing a schematic graph of the intake air temperature and the supply air temperature with respect to the atmospheric temperature when the control according to the second embodiment is performed. 11, the target value t _s2 supply air temperature t ₂ regardless of conditions of the fuel gas shows the case of a constant. The atmospheric temperature in the graph of FIG. 11 shows an example of the monthly average temperature in the area where the gas engine system 1 is installed in one year. Similar to the graph of FIG. 2, the control for cooling the intake air is not performed _{when the atmospheric temperature is less than the reference temperature t c1} and the intake air temperature lower limit value t _{1 min or more of the turbocharger 4.} In this case, the supply air temperature t ₂ is maintained at the target temperature t _s2 by the charge air cooler 5.

Even in the period in which the control for cooling the intake air not performed (the state without cooling the intake air supply air temperature t ₂ is under atmospheric temperature is maintained at a target temperature t _s2 by the charge air cooler 5A) while the intake air temperature t ₁ the controller 26 can be achieved when using the cooling water of the cooling water cooling system 27 from the ambient temperature to a target value t _s1, by adjusting the three-way valve 52, the target supply air temperature t ₂ The temperature may be adjusted to _{t s2.} As a result, the work load of the compressor 10 of the supercharger 4 is reduced, so that the power generation efficiency can be improved.

Further, in the summer, when the atmospheric temperature reaches the reference temperature t _c1 or higher, the intake air temperature adjusting device 6B executes control to cool the intake air. As a result, the intake air temperature t ₁ is controlled _{so that the supply air temperature t 2 maintains the target temperature t sq} 2 in the power generation efficiency priority mode regardless of the atmospheric temperature and the second cooling water temperature.

On the other hand, in winter, when the atmospheric temperature becomes _{equal to or less than the lower limit of the intake air temperature t 1 min} in the compressor 10 of the turbocharger 4, when the outside air is introduced as the intake air as it is, the compressor 10 of the turbocharger 4 Due to design restrictions, the compressor 10 of the turbocharger 4 cannot be operated. Therefore, when the atmospheric temperature becomes the intake air temperature lower limit value t _{1 min} or less, the intake air temperature adjusting device 6 executes control to heat the intake air (power generation efficiency priority mode). As a result, the intake air temperature t ₁ is maintained at a temperature t _{1c 2} of the intake air temperature lower limit value t _{1 min} or more regardless of the atmospheric temperature, and the compressor 10 of the turbocharger 4 can be operated while introducing outside air. At this time, the temperature of the second cooling water that always cools the second air supply cooler 15 by the three-way valve 21A of the air supply cooling device 5A becomes a constant temperature for the supply air emitted from the compressor 10 of the supercharger 4. It is adjusted to, by the flow rate through the three-way valve 52 to the second charge air cooler 15 is adjusted, the supply air temperature t ₂ is maintained at the target temperature t _sq2 in the power generation efficiency priority mode. Therefore, the supply air temperature t ₂ can be maintained at a _{temperature (t sq2} ) at which the power generation efficiency becomes high throughout the year.

Further, in the present embodiment, the heat recovery priority mode can be executed instead of the power generation efficiency priority mode. Target temperature _{t sr2} supply air temperature _{t 2} in the heat recovery priority mode is set to a temperature close to the maximum value (supply air temperature upper _{limit) t 2max} or less and supply air temperature upper limit _{t 2max} in the supply air temperature _{t 2} .. _{However, the target temperature t 1c3} of the intake air temperature corresponding to this needs to be equal to or less than the _{intake air temperature upper limit value t 1max} in the compressor 10 of the supercharger 4 in the compressor 10 of the supercharger 4. Thus, as the target temperature _{t 1c3} target temperature _{t sr2} are supply air temperature upper limit _{t 2max} or less and intake air temperature _{t 1} of the supply air temperature _{t 2} is not more than the intake air temperature upper limit _{t 1max,} the supply air temperature _{t 2} The target temperature t _sr2 is set.

In the heat recovery priority mode, the post-combustion gas temperature t ₃ and the exhaust gas temperature t ₄ can be achieved by setting _{the supply air temperature t 2} to a temperature close to the supply air temperature upper limit t _{2max allowed by the gas engine 2.} Can be raised. At this time, intake air temperature _{t 1} regardless of atmospheric temperature, is maintained at a higher temperature _{t 1c3} than the temperature _{t 1c2} in the power generation efficiency priority mode.

The power generation efficiency priority mode and the heat recovery priority mode can be switched as appropriate. For example, since the atmospheric temperature is higher during the day than at night during the day, the amount of hot water required to heat a building or the like is reduced. Therefore, during the daytime, the operation is performed in the power generation efficiency priority mode, and the hot water or steam whose exhaust heat is recovered under the power generation efficiency priority mode is used for heating or the like. On the other hand, since the atmospheric temperature drops at night, the amount of hot water required is larger than during the day. Therefore, at night, it is operated in the heat recovery priority mode that can supply a larger amount of hot water or steam. Further, for example, the heat recovery priority mode can be executed even when the atmospheric temperature is high such as in summer. In this case, for example, since a large amount of cold water is required to cool the building during the daytime in the daytime, it is operated in the heat recovery priority mode in order to recover more heat in order to produce the cold water, and the atmosphere. Since the amount of cold water used in cooling decreases at night when the temperature drops, the control mode (power generation efficiency priority mode or control mode in which intake air temperature control is not performed) is operated in which the exhaust heat recovery amount is smaller than the heat recovery priority mode.

Thus, in the heat recovery priority mode, the supply air temperature t ₂ rather than the target temperature t _s2 for high power generation efficiency, by dare higher temperatures than can increase the exhaust gas temperature t ₄ As a result, the amount of heat recovered from the gas engine system 1 can be increased, and the total thermal efficiency of the entire gas engine system 1 can be increased.

[Modification example]
In the second embodiment as well, the controller 26 may acquire the post-combustion gas temperature t _{3 in addition to acquiring the supply air temperature t 2} as in the first embodiment. If the operation is performed during the period when one of the temperature detection sensors fails, the operation may be continued with only the signal of the other temperature detection sensor. Further, the controller 26 _{acquires both the supply air temperature t 2} and the post-combustion gas temperature t _3, and monitors the operating state of the gas engine 2 by comparing each temperature with the set target temperature. May be done.

Further, in addition _{to acquiring the supply air temperature t 2} , the exhaust gas temperature t ₄ may be acquired. The exhaust gas temperature t ₄ is the outlet temperature of the turbine 11 of the turbocharger 4, and is detected by the exhaust gas temperature detection sensor 40. Controller 26, that is both get the supply air temperature _{t 2} and exhaust gas temperature _{t 4,} a temperature _t 2, _{t 4} obtained, to compare the target temperature _t s2 that is set in _{each, t s4} and respectively Therefore, the operating state of the gas engine 2 may be monitored.

Further, in the second embodiment, the configuration in which the cooling pipe 28 and the heating pipe 37 are provided and the intake air can be cooled and heated by switching the piping connected to the intake air introduction unit 8 is illustrated, but the temperature regulator 25B The cooling pipe 28, the cooling water cooling device 27, and the on-off valves 33 and 34 may be eliminated, and only the heating pipe 37 may be provided. That is, the temperature regulator may be configured to include a heating pipe that supplies hot water from the exhaust heat recovery unit 44 to the intake air introduction unit 8 in order to heat the intake air. According to this configuration, even when the temperature of the atmosphere becomes low, such as in winter, and it becomes necessary to raise the _{intake air temperature to the intake air temperature lower limit value t 1 min or more due to the design limitation of the compressor 10 of the turbocharger 4.} The intake air temperature can be raised to the _{lower limit value of the intake air temperature t 1 min} or more without using complicated mechanical equipment for switching from the atmospheric intake air to the indoor intake air. Accordingly, while securing design limitation of the compressor 10 of the turbocharger 4, a supply air temperature t ₂ can be controlled to the target temperature t _s2.

In the second embodiment as well, as in the first embodiment (FIG. 1), the cooling source 18 may be provided instead of the radiators 35 and 36 as the cooling source of the air supply cooling device 5B.

Further, also in the second embodiment, similarly to the modification 3 (FIG. 7) of the first embodiment, the air supply cooling device 5B uses the cooling water from the second radiator 36 as the first air supply cooler 14 and A supply air cooling cooling water path 56G supplied to each of the second air supply coolers 15 and a gas engine cooling water path 54G provided separately from the supply air cooling cooling water path 56G for cooling the gas engine 2. , May be provided. In this case, the gas engine cooling path 54G for cooling the gas engine 2 is connected to the first radiator 35, and the exhaust heat recovery unit 44 is provided on the downstream side of the gas engine 2 in the gas engine cooling path 54G to provide gas. The exhaust heat generated by the engine 2 may be recovered as hot water.

[Embodiment 3]
Next, Embodiment 3 of the present invention will be described. FIG. 12 is a block diagram showing a schematic configuration of the gas engine system 1C according to the third embodiment of the present invention. In FIG. 12, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

Gas engine system 1C is different from the first embodiment in the present embodiment has a function of heating the intake air temperature t ₁ at a temperature regulator 25C of the intake air temperature adjusting device 6C, first as a heat source for heating 2 The exhaust heat in the cooling water path 17 is used as a direct heating source. Therefore, the exhaust heat recovery unit 55C is provided on the downstream side of the second air supply cooler 15 in the second cooling water path 17.

More specifically, the exhaust heat recovery unit 55C is configured such that the heating pipe 37C to the intake air introduction unit 8 branches on the downstream side of the heat exchanger 20 of the second cooling water path 17. An on-off valve 41 is provided between the going path connecting portion and the returning path connecting portion of the second cooling water path 17 to the heating pipe 37C. The on-off valves 38 and 41 are controlled to open and close by the switching signal S2 from the controller 26.

When the intake air does not need to be heated, the on-off valve 38 is closed and the on-off valve 41 is opened. As a result, the second cooling water path 17 bypasses the heating pipe 37C. When the intake air needs to be heated, the on-off valve 38 is opened and the on-off valve 41 is closed. As a result, the second cooling water that has passed through the second air supply cooler 15 and the heat exchanger 20 in the second cooling water path 17 is introduced into the heating pipe 37C and supplied to the heat exchanger 30. As a result, the intake air introduced from the intake air introduction unit 8 is heated.

Also in this embodiment, the controller 26, such that the supply air temperature t ₂ which is supplied to the gas engine 2 reaches the predetermined target temperature t _s2, controls the intake air temperature t _1. The controller 26 can be executed by switching between the power generation efficiency priority mode and the heat recovery priority mode as in the second embodiment. Therefore, if the power generation efficiency priority mode, the target temperature _{t s2} of the air supply temperature _{t 2,} such as intake air temperature _{t 1} is the intake air temperature lower limit value _{t 1min} or more temperature _{t 1c2} in the compressor 10 of the turbocharger 4 The temperature is set to _{t sq2.} Also, in the case of heat recovery priority mode, the target temperature _{t s2} of the air supply temperature _{t 2,} the supply air temperature upper limit _{t 2max} or less and supply air temperature upper limit _t temperature close to _2max (and intake air temperature _{t 1} of the target temperature t _{The temperature t sr2} is set so that 1c3 becomes the intake air temperature upper limit value t _1max or less).

For example, when the area where the gas engine system 1 is laid is an area where the temperature becomes low throughout the year or seasonally, the intake air temperature t ₁ is raised _{to the intake air temperature lower limit t 1 min or more in the compressor 10 of the turbocharger 4.} Let me. At this time, since the atmospheric temperature is low, the temperature of the three-way valve 21 of the second cooling water path 17 can be adjusted to the set value. Therefore, the flow rate control of the cooling water flowing through the second air supply cooler 15 can be performed by adjusting the three-way valve 52. As a result, the gas engine 2 can be operated stably in a highly efficient state.

Further, according to the above configuration, the exhaust heat is recovered in the second cooling water path 17. Originally, the exhaust heat in the second cooling water path 17 is dissipated to the atmosphere at the cooling source 18. According to the present embodiment, the exhaust heat dissipated from the cooling source 18 is reduced by heating the intake air by utilizing the exhaust heat dissipated from the atmosphere. Further, by setting the heat recovery priority mode, the amount of exhaust heat recovery is increased and the total heat efficiency is improved. On the other hand, the exhaust heat in the return path of the first cooling water path 16 at which the cooling water becomes hotter can be separately recovered and the entire amount can be used for other purposes such as heating.

In the present embodiment, the heat exchanger 42 is provided between the first air supply cooler 14 and the heat exchanger 20 in the first cooling water path 16. The heat exchanger 42 may be the same as the heat exchanger configured as the exhaust heat recovery unit 44 in the first and second embodiments, but has different reference numerals because of different uses. The exhaust heat recovered from the first cooling water path 16 in the heat exchanger 42 is supplied to the outside of the gas engine system 1C as a heat source.

[Modification example]
Also in the third embodiment, similarly to the first embodiment, the controller 26 acquires the post-combustion gas temperature t ₃ and / or the exhaust gas temperature t _{4 in addition to acquiring the supply air temperature t 2.} and, by comparing the temperature t _3, t ₄ and the target temperature is set for each t _s3, t _s4 obtained may be carried out to monitor the operating state of the gas engine 2.

In the third embodiment, the configuration in which the heating pipe 37C connected to the intake air introduction unit 8 is provided and the intake air can be heated is illustrated. However, in the temperature regulator 25C, the cooling in the first embodiment is performed instead of the heating pipe 37C. The configuration may include a water cooling device 27 and a cooling pipe 28. That is, the intake air may be cooled by cooling the intake air cooling water that cools the intake air by using the exhaust heat recovered from the second cooling water passage 17. Further, as in the second embodiment, the cooling function and the heating function may be switchable.

As described above, the second cooling water flowing through the second cooling water path 17 has a lower temperature than the first cooling water flowing through the first cooling water path 16, so that the heat conversion efficiency in the cooling water cooling device 27 is high. , It is lower than the case where the exhaust heat recovered from the first cooling water path 16 is used as the heat source as in the first embodiment.

In the third embodiment and its modifications, the radiators 35 and 36 are used instead of the cooling source 18 as the cooling source of the air supply cooling device 5, as in the modification 1 (FIG. 5) of the first embodiment. The first cooling water path 16A and the second cooling water path 17A may be configured as independent paths.

Further, also in the third embodiment, similarly to the modified example 2 (FIG. 6) of the first embodiment, the air supply cooling device 5 is a first air supply cooler 14 and a second air supply cooler 15, respectively. Even if it is provided with a supply air cooling cooling water path 56F for supplying cooling water to the air supply and a gas engine cooling water path 54F provided separately from the supply air cooling cooling water path 56F for cooling the gas engine 2. Good. In this case, the exhaust heat recovery unit 44 may be provided on the downstream side of the gas engine 2 in the gas engine cooling path 54F, and the exhaust heat generated by the gas engine 2 may be recovered as hot water.

FIG. 13 is a block diagram showing a schematic configuration of the gas engine system 1D according to the first modification of the third embodiment of the present invention. In FIG. 13, the same components as those in FIG. 12 are designated by the same reference numerals, and description thereof will be omitted. The air supply cooling device 5D in the first modification has the same configuration as the air supply cooling device 5A shown in FIG. However, in FIG. 13, the reference numerals 5A, 16A, 17A, 21A, 23A in FIG. 5 are reassigned to the reference numerals 5D, 16D, 17D, 21D, 23D.

Also in the first modification, the temperature controller 25D of the intake air temperature regulator 6D includes an exhaust heat recovery unit 55D and a heating pipe 37D as in the third embodiment. Here, the exhaust heat recovery unit 55D is provided on the downstream side of the first air supply cooler 14 in the first cooling water path 16D. An on-off valve 41 is provided between the going path connecting portion and the returning path connecting portion of the first cooling water path 16D to the heating pipe 37D.

FIG. 14 is a block diagram showing a schematic configuration of the gas engine system 1E according to the second modification of the third embodiment of the present invention. In FIG. 14, the same components as those in FIG. 13 are designated by the same reference numerals, and the description thereof will be omitted. The air supply cooling device 5E in the second modification has the same configuration as the air supply cooling device 5E shown in FIG. However, in FIG. 14, the reference numerals 5D, 16D, 17D, 21D, and 23D in FIG. 13 are reassigned to the reference numerals 5E, 16E, 17E, 21E, and 23E.

Also in the second modification, the temperature controller 25E of the intake air temperature regulator 6E includes an exhaust heat recovery unit 55E and a heating pipe 37E as in the third embodiment. Here, the exhaust heat recovery unit 55E is provided on the downstream side of the second air supply cooler 15 in the second cooling water path 17E. An on-off valve 41 is provided between the going path connecting portion and the returning path connecting portion of the second cooling water path 17E to the heating pipe 37E.

In the modified examples 1 and 2 of the third embodiment shown in FIGS. 13 and 14, the air supply cooling devices 5D and 5E are connected to the second radiator 36 as in the modified example 3 (FIG. 7) of the first embodiment. Cooling water path 56G for air supply cooling that supplies the cooling water of the above to each of the first air supply cooler 14 and the second air supply cooler 15, and the cooling water path 56G for air supply cooling for cooling the gas engine 2. It may be provided with a gas engine cooling path 54G provided separately from the above. In this case, the gas engine cooling path 54G for cooling the gas engine 2 is connected to the first radiator 35, and the exhaust heat recovery unit 44 is provided on the downstream side of the gas engine 2 in the gas engine cooling path 54G to provide gas. The exhaust heat generated by the engine 2 may be recovered as hot water.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various improvements, changes, and modifications can be made without departing from the spirit of the present invention.

INDUSTRIAL APPLICABILITY The present invention is useful for controlling the supply air temperature suitable for the operating requirements of various gas engines regardless of atmospheric conditions in a gas engine system.

1,1A, 1B, 1C, 1D, 1E, 1F, 1G Gas engine system 2 Gas engine 3 Generator 4 Supercharger 5,5A, 5D, 5E, 5F, 5G Air supply cooling device 6,6C, 6D, 6E Intake air temperature regulator 8 Intake introduction unit 10 Compressor 14, 14F, 14G 1st air supply cooler 15, 15F, 15G 2nd air supply cooler 16, 16A, 16F, 16G 1st cooling water path 17, 17A, 17F , 17G 2nd cooling water path 25, 25B, 25C, 25D, 25E Temperature regulator 26 Controller 27 Cooling water cooling device 28 Cooling pipe 37 Heating pipe 33, 34, 38 On-off valve (pipe switching part)
44, 55C, 55D, 55E Exhaust heat recovery unit

Claims (12)

With a gas engine
A generator that generates electricity by the rotational power of the gas engine,
A supercharger having a compressor that compresses the supply air supplied to the gas engine and a turbine that generates power from the post-combustion gas discharged from the gas engine.
An air supply cooling device that cools the supply air compressed by the compressor using cooling water cooled by the atmosphere, and
It is equipped with an intake air temperature adjusting device that adjusts the temperature of the intake air supplied to the compressor from the intake air introduction unit that takes in the atmosphere.
The intake air temperature adjusting device is
An exhaust heat recovery unit that recovers the exhaust heat generated by the gas engine,
A temperature controller that adjusts the temperature of the intake air using the recovered exhaust heat,
Including a controller for controlling the temperature controller,
The controller acquires the temperature of the supply air supplied to the gas engine or the temperature of the post-combustion gas discharged from the gas engine, and takes in the intake air so that the acquired temperature becomes a predetermined target temperature. A gas engine system that controls the temperature of the engine. The gas engine system according to claim 1, wherein the temperature controller includes a cooling water cooling device that cools cooling water for cooling the intake air by using the exhaust heat recovered by the exhaust heat recovery unit. The waste heat recovery unit recovers the waste heat as hot water or steam.
The temperature controller
A cooling pipe that supplies cooling water from the cooling water cooling device to the intake intake portion, and
A heating pipe that supplies the hot water from the exhaust heat recovery unit to the intake air introduction unit to heat the intake air, and a heating pipe.
The gas engine system according to claim 2, further comprising a pipe switching unit for switching the pipe connected to the intake air introduction unit between the cooling pipe and the heating pipe. The waste heat recovery unit recovers the waste heat as hot water or steam.
The gas engine system according to claim 2 or 3, wherein the cooling water cooling device is a hot water or steam absorption chiller that produces the cooling water using the hot water or steam. The waste heat recovery unit recovers the waste heat as hot water.
The gas engine system according to claim 1, wherein the temperature controller includes a heating pipe that supplies the hot water from the exhaust heat recovery unit to the intake air introduction unit in order to heat the intake air. The controller has a first control mode in which the target temperature set for heating the air supply is set as a predetermined first target temperature, and the target temperature set for heating the air supply. The gas engine system according to claim 3 or 5, wherein the second control mode in which the temperature is set to a second target temperature higher than the first target temperature can be switched and executed. The air supply cooling device
In the first cooling water path for cooling the gas engine, a first air supply cooler provided in the return path from the gas engine and
A second air supply cooler provided in a second cooling water path different from the first cooling water path is provided.
The first air supply cooler is provided on the upstream side of the second air supply cooler in the air supply path between the supercharger and the gas engine.
The gas engine system according to any one of claims 1 to 6, wherein the exhaust heat recovery unit is provided on the downstream side of the first air supply cooler in the return path. The air supply cooling device
In the first cooling water path for cooling the gas engine, a first air supply cooler provided in the return path from the gas engine and
A second air supply cooler provided in a second cooling water path different from the first cooling water path is provided.
The first air supply cooler is provided on the upstream side of the second air supply cooler in the air supply path between the supercharger and the gas engine.
The gas engine system according to any one of claims 1 to 6, wherein the exhaust heat recovery unit is provided on the downstream side of the second air supply cooler in the second cooling water path. The air supply cooling device
A first air supply cooler provided in the air supply path between the supercharger and the gas engine, and
A second air supply cooler provided on the downstream side of the first air supply cooler in the air supply path, and
A cooling water path for air supply cooling that supplies cooling water to each of the first air supply cooler and the second air supply cooler, and
A gas engine cooling path provided separately from the air supply cooling cooling water path for cooling the gas engine is provided.
The gas engine system according to any one of claims 1 to 6, wherein the exhaust heat recovery unit is provided on the downstream side of the gas engine in the gas engine cooling path. The compressor blades of the supercharger have a highly efficient shape optimized for a temperature in a predetermined range based on a target temperature set for the temperature of the supply air, according to claims 1 to 9. The gas engine system described in either. The turbine blades of the turbocharger have a highly efficient shape optimized for a temperature in a predetermined range based on a target temperature set for the temperature of the gas after combustion, according to claims 1 to 10. The gas engine system described in either. Any of claims 1 to 10, wherein the controller acquires a predetermined value indicating the properties of the fuel gas supplied to the gas engine, and sets the target temperature to a value corresponding to the predetermined value. The gas engine system described in.

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