JP2014034924A - Exhaust heat recovery device of internal combustion engine and cogeneration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust heat recovery device of an internal combustion engine, which has a heat pump to generate steam using, as a heat absorption source, heat quantity of either a lubricant system of the internal combustion engine or a closed type circulating cooling water system directly cooling the internal combustion engine, capable of generating steam without increasing power consumption or fuel consumption or without practically using power or fuel.SOLUTION: An exhaust heat recovery device of an internal combustion engine comprises: an exhaust heat recovery boiler which generates steam by recovering heat from combustion exhaust of the internal combustion engine; and a heat pump which also generates the steam with lubricant of the internal combustion engine or engine cooling liquid as a heat absorption source. The exhaust heat recovery boiler is configured to generate super-heated steam. The heat pump has a back-pressure type steam turbine which uses the super-heated steam generated by the exhaust heat recovery boiler as drive steam, a drive source, of a compressor to compress a cooling medium or the steam inside the heat pump. Exhaust stem from the back-pressure type steam turbine is used as supply steam to a steam demander.

Description

  The present invention relates to an exhaust heat recovery device and a cogeneration system for an internal combustion engine, and in particular, directly cools an exhaust heat recovery boiler that generates steam from combustion exhaust gas of the internal combustion engine, a lubricating oil system of the internal combustion engine, and the internal combustion engine. The present invention relates to an exhaust heat recovery apparatus for an internal combustion engine having a heat pump that generates steam by using the amount of heat of the hermetic circulating cooling water system as a heat absorption source.

  Although an internal combustion engine is installed for the purpose of driving a machine or a generator, a lot of heat loss occurs. The main heat loss sources are roughly classified into three types: exhaust gas, lubricating oil, and engine coolant.

  Among these, since the temperature of the exhaust gas is about 350 ° C. or more, it is generally performed to install an exhaust heat recovery boiler at the exhaust gas outlet of the internal combustion engine and recover the thermal energy of the exhaust gas as steam energy.

  On the other hand, for the lubricating oil and engine coolant, the lubricating oil cooling temperature is 60 ° C. to 75 ° C., and the engine coolant temperature of the closed circulation cooling system that directly cools the internal combustion engine is 85 ° C. to 95 ° C. It is possible to produce hot water up to about 90 ° C. and supply it to the outside. However, the use of hot water is often limited to heat source water for heating in the cold season. Further, the engine cooling water at 85 ° C. to 95 ° C. may be used for cooling in summer as a driving heat source of the hot water absorption refrigerator. For example, Japanese Patent Application Laid-Open No. H10-133707 discloses a method in which steam is generated by exhaust gas and supplied to the outside, and engine cooling water is used as a driving heat source for a hot water absorption refrigerator.

  However, hot water and cold water produced using hot water have fewer uses than steam, and if there is no use, the amount of heat of these coolants is transferred to the cooling water cycle via a heat exchanger. In many cases, heat is exhausted and exhausted from the cooling tower to the atmosphere.

  Under such circumstances, heat pumps that generate steam exceeding 7.0 MPa and 160 ° C. using hot water of about 70 ° C. as a heat absorption source have been put into practical use in recent years. The temperature range required as the heat absorption source of this heat pump is about 70 ° C., the lubricating oil temperature of the lubricating oil system of the internal combustion engine is 60 ° C. to 75 ° C., and the temperature of the coolant of the closed circulation cooling system is 85 ° C. to Since it is 95 ° C., when these systems are used as the heat absorption source of the heat pump, the amount of steam generated from the internal combustion engine can be greatly increased.

  Although it is not an exhaust heat recovery device of an internal combustion engine, Non-Patent Document 1 describes that steam at about 120 ° C. is generated from hot wastewater in a factory or the like by using a heat pump and the steam is supplied.

JP-A-3-237256

“Development and sales of high-efficiency steam supply system“ Steam Glow Heat Pump ”” [online], February 21, 2011, Kobe Steel Co., Ltd., [December 22, 2011 search], Internet <URL : Http://www.kobelco.co.jp/topics/2011/02/1184033_11064.html>

  In Non-Patent Document 1, an electric motor is driven to drive a refrigerant compressor inside a heat pump. When such a technique is applied to an exhaust heat recovery device for an internal combustion engine, the result is that energy saving equipment for recovering engine exhaust heat obstructs obtaining the generated power that is the original installation purpose of the internal combustion engine. End up. That is, when the generator is driven by the internal combustion engine, the amount of power supplied to the outside is reduced. Further, even when a machine is driven by an internal combustion engine, in order to drive a compressor, which is a component of a heat pump, even though power is saved by using the internal combustion engine instead of an electric motor that drives the machine. It becomes necessary to supply power from the outside.

  An object of the present invention is to provide an exhaust heat recovery apparatus for an internal combustion engine having a heat pump that generates steam using the amount of heat of a lubricating oil system of the internal combustion engine or a closed circulation cooling water system that directly cools the internal combustion engine as a heat sink. An object of the present invention is to provide an exhaust heat recovery device for an internal combustion engine capable of generating steam without increasing the amount or the amount of fuel used, or substantially without supplying electric power or fuel.

  In order to solve the above problems, the present invention generates an exhaust heat recovery boiler that recovers heat from combustion exhaust gas of an internal combustion engine to generate steam, and generates steam using the lubricating oil or engine coolant of the internal combustion engine as a heat sink. A heat pump is provided, and the exhaust heat recovery boiler is configured to generate superheated steam, and the superheated steam generated in the exhaust heat recovery boiler as a driving source of a compressor that pressurizes the cooling medium and / or steam inside the heat pump. This is characterized in that a back pressure type steam turbine that uses as a driving steam is installed, and the exhaust steam of the back pressure type steam turbine is also used as supply steam to a steam demand destination.

  According to the present invention, hermetic circulation cooling that directly cools a lubricating oil system or an internal combustion engine of an internal combustion engine without increasing power consumption or fuel consumption, or substantially without supplying power or fuel. Steam can be generated using a heat pump with the heat quantity of the water system as an endothermic source.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is a system diagram of a combined power generation facility equipped with an exhaust heat recovery apparatus for an internal combustion engine according to a first embodiment of the present invention. The system diagram of the combined power generation equipment provided with the exhaust-heat recovery apparatus of the internal combustion engine by a comparative example. The systematic diagram of the combined power generation equipment which comprised the exhaust-heat recovery apparatus of the internal combustion engine of Example 2 by this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  The exhaust heat recovery device for an internal combustion engine in the present embodiment includes an exhaust heat recovery boiler that recovers heat from the combustion exhaust gas of the internal combustion engine to generate steam, and a heat pump that generates steam using the coolant of the internal combustion engine as a heat absorption source, The compressor for pressurizing the cooling medium inside the heat pump and the compressor for pressurizing the generated steam are driven by a back pressure steam turbine using the generated steam (superheated steam) of the exhaust heat recovery boiler of the internal combustion engine.

  In this embodiment, after working at each back pressure steam turbine, the exhaust steam of the back pressure steam turbine can be used at an external steam demand destination (the steam condition required at the steam demand destination). Thus, the pressure and temperature conditions of the inlet steam of each back pressure turbine, that is, the pressure and temperature of the generated steam in the exhaust heat recovery boiler are adjusted. Specifically, in consideration of the work in each back pressure steam turbine, the heat transfer surface of the exhaust heat recovery boiler, the drum and the evaporator, the feed water pump, and the like are configured so as to have a necessary pressure and superheat degree.

  FIG. 1 shows a case where an exhaust heat recovery apparatus for an internal combustion engine according to the present invention is applied to a cogeneration system. That is, FIG. 1 shows an exhaust heat recovery boiler 4 that generates heat by recovering the combustion exhaust gas of the gas engine 1 for the purpose of generating power by driving the generator 2, and the engine hermetic circulation cooling of the gas engine 1. The case where this invention is applied to the exhaust-heat recovery apparatus of the internal combustion engine provided with both the heat pumps 22 which generate | occur | produce a vapor | steam using the water system 11 as a heat sink is shown.

  In this embodiment, the exhaust gas duct 3 of the gas engine 1 for driving the generator 2 is connected to the exhaust heat recovery boiler 4, and steam is generated using the thermal energy of the exhaust gas. Generally, in the exhaust heat recovery boiler 4 of a gas engine, saturated steam of about 0.7 MPa is often supplied to customers. In this embodiment, the steam generated in the exhaust heat recovery boiler 4 is used to drive back pressure steam turbines 45 and 48, which will be described later, and the exhaust steam is supplied to the customer as saturated steam of about 0.7 MPa. While raising the head of feed water pump 6, superheater 42 is installed in exhaust heat recovery boiler 4, and it raises and raises pressure.

  The exhaust heat recovery boiler 4 using the exhaust gas of the gas engine of the present embodiment is specifically configured as follows. First, the boiler feed water supplied from the feed water pipe 5 by the feed water pump 6 is heated by the economizer heat transfer pipe 7 and sent to the boiler drum 8. An evaporator 9 is connected to the boiler drum 8, and steam is generated by the thermal energy received from the exhaust gas in the evaporator 9. The generated steam is sent to the superheater 42 connected to the boiler drum 8 via the boiler drum 8, and the temperature is raised and increased in the superheater 42 to become superheated steam. Here, since the exhaust gas temperature of the gas engine 1 is generally about 350 ° C. or higher, the outlet steam temperature of the exhaust heat recovery boiler 4 can be raised to about 300 ° C. Also, the pressure is increased by the feed water pump 6 so that the pressure is about 3 MPa at the location of the superheated steam pipe 43 at the outlet of the superheater 42.

  On the other hand, the lubricating oil and the engine coolant of the gas engine 1 are taken out through a lubricating oil pipe (lubricating oil system) 15 and an engine hermetic circulating cooling water pipe (sealed circulating cooling system) 11 respectively, and a lubricating oil pump 16 that is a circulating pump. The engine hermetic circulating cooling water pump 12 sends the oil to the lubricating oil cooler 17 and the engine hermetic circulating cooling water cooler 13, respectively. The exhaust heat of the lubricating oil and the engine coolant of the gas engine 1 is exchanged with the cooling water of the secondary cooling water pipe (secondary cooling water system) 19 in the lubricating oil cooler 17 and the engine hermetic circulating cooling water cooler 13, respectively. And finally, it has the structure of the waste heat treatment radiated from the cooling tower 21 to the atmosphere. In the figure, 14 is an engine hermetic circulating cooling water temperature control valve, 18 is a lubricating oil temperature control valve, and 20 is a secondary cooling water pump.

  In the present embodiment, an example is shown in which exhaust heat is pumped to the heat pump 22 using the engine hermetic circulating cooling water heat exchanger 23 installed in the hermetic circulating cooling system 11. In the heat pump heat absorption source circulation pump 25, the heat absorption source liquid passes through the heat pump heat absorption source circulation pipe (heat pump heat absorption source liquid circulation system) 26, and the engine sealed circulation cooling water heat exchanger 23 and the heat pump refrigerant circulation pipe (cooling medium) in the heat pump 22. Circulation path) 28 flows through the heat pump evaporator 24 installed on the circuit. The engine exhaust heat of the gas engine 1 drawn up from the engine hermetic circulation cooling water pipe 11 by the engine hermetic circulation cooling water heat exchanger 23 is cooled by the heat pump evaporator 24 installed on the heat pump refrigerant circulation pipe (cooling medium circulation path) 28. Used for medium vaporization.

  The vaporized cooling medium is sent to and compressed by the refrigerant compressor 29, and is condensed by heating the hot water circulating through the heat pump hot water circulation pipe (heat pump hot water circulation system) 33 in the refrigerant condenser 31, and the refrigerant expansion valve 30. Then, it is sent again to the heat pump evaporator 24.

  A part of the heat exhausted from the above path to the engine hermetic circulating cooling water system 11 of the gas engine 1 is transferred to the cooling medium of the heat pump 22 via the engine hermetic lubricating cooling water heat exchanger 23 and the heat pump evaporator 24. Further, the power of the refrigerant compressor 29 is applied, and the hot water circulating through the heat pump hot water circulation system 33 is pumped through the refrigerant condenser 31.

  The heat pump circulating hot water after leaving the refrigerant condenser 31 is sent to the hot water flash tank 34 to generate flash steam. The generated flash steam is sent to the steam compressor 39 via the flash steam pipe 38, and the pressure is increased to a steam pressure necessary for supplying to the customer, and then sent to the customer. To the warm water flash tank 34, makeup water is continuously sent by a makeup water pump 37 of a makeup water pipe (warm water circulation makeup water system) 36, and the water level of the warm water flash tank 34 is kept constant.

  In the present embodiment, the refrigerant compressor 29 and the steam compressor 39 are driven by the back pressure type in which the superheated steam generated in the exhaust heat recovery boiler 4 is driven using steam pipes 44 and 47 branched from the steam pipe 43, respectively. The heat pump is driven by a back pressure steam turbine 45 for driving a heat pump refrigerant compressor and a back pressure turbine 48 for driving a heat pump steam compressor, which are steam turbines.

  Further, in this embodiment, the outlet steam (exhaust steam) of each of the back pressure steam turbines 45 and 48 is sent to the steam demand through the back pressure steam turbine exhaust pipes 46 and 49, respectively. The outlet steam of each back pressure steam turbine 45, 48 is led to the steam supply header 50. The steam supplied from the steam compressor 39, which is the output of the heat pump 22, is also connected to the steam supply header 50 from the heat pump outlet steam pipe 41, and the generated steam is supplied from the steam supply header 50 to the customer. Air is supplied through the pipe 51.

  When the heat pump 22 is stopped, the steam generated in the exhaust heat recovery boiler 4 passes through the turbine bypass pipe (turbine bypass system) 52 and the turbine bypass valve 53 and the temperature reducer 54 require the required steam pressure and temperature conditions at the demand destination. The reduced pressure is reduced to the vapor supply header 50. In this case, the temperature-reduced water to the temperature reducer 54 branches from the outlet of the feed water pump 6 of the exhaust heat recovery boiler 4, and the flow rate is adjusted by the temperature control valve 56 installed in the temperature-reduced water supply pipe 55. The steam temperature downstream of the vessel 54 is controlled.

  Next, the effect of this embodiment will be described in comparison with a comparative example.

  In the comparative example, as shown in FIG. 2, the refrigerant compressor 29 and the steam compressor 39 are not driven by the back pressure steam turbines 45 and 48 as in this embodiment, but are driven by the electric motors 32 and 40, respectively. It has come to be. In the exhaust heat recovery boiler 4, the steam generated in the evaporator 9 is saturated outside the system (destination) via the drum 8 (saturation of about 0.7 MPa) as in the exhaust gas recovery in the conventional gas engine. Steam) is sent. Further, the steam whose pressure is increased from the steam compressor 39 driven by the electric motor 40 is sent to the customer. In the comparative example shown in FIG. 2, the refrigerant compressor 29 and the vapor compressor 39 inside the heat pump 22 are driven by the electric motors 32 and 40, respectively. Therefore, the engine hermetic circulating cooling water system 11 of the internal combustion engine (gas engine). As a result, the energy-saving equipment for recovering the exhaust heat from the engine prevents the generation of the generated power, which is the original installation purpose of the internal combustion engine. That is, in this comparative example, the generator 2 is driven by the gas engine 1, but the amount of power supplied to the outside is reduced.

  The coefficient of performance of the heat pump of the type shown in FIG. 2, which is currently in practical use, is defined as an electric motor input with respect to the energy obtained until the makeup water is output as steam in the heat pump. A number of 5 has been reported. This indicates that the make-up water-steam system receives 2.5 times the heat energy for an electric input of 1.0 to the motor. Here, a value obtained by subtracting the electric energy input 1.0 to the electric motor from the received heat energy output 2.5, 1.5 is the ratio of the energy pumped from the engine hermetic circulating cooling water system 11 of the internal combustion engine. That is, since the ratio of the electric energy required for pumping up 1.5 heat energy is 1.0, 2/3 of the heat energy of the pumped heat absorption source is required. Considering that the power generation efficiency of the gas engine power generation facility is about 50%, it cannot be said that it is an advantageous energy saving means.

  An internal combustion engine is an engine that converts chemical energy into heat energy and extracts mechanical energy therefrom. When a generator is driven by an internal combustion engine, mechanical energy is further converted into electric energy, which is the final output. In the comparative example shown in FIG. 2, the electric energy thus finally obtained is consumed. Thus, it is converted into heat energy which is an intermediate output again, that is, steam is produced.

  In contrast, in this embodiment, the pressure and temperature of the steam generated in the exhaust heat recovery boiler 4 is higher than that in the comparative example, so that the weight flow rate of the steam generated in the exhaust heat recovery boiler 4 decreases. The internal energy of steam is almost the same. Since almost the entire amount of this steam is sent to the customer after working in the back pressure steam turbines 45 and 48, there is almost no loss.

  On the heat pump 22 side, the amount of heat pumped up using the engine hermetic circulating cooling water system 11 of the gas engine as a heat absorption source and the work of the back pressure steam turbine 45 are converted into refrigerant liquid by the evaporator 24 and the refrigerant compressor 29, respectively. It is stored and converted into the internal energy of the hot water of the circulating hot water system 33 via the condenser 31. Since the steam generated in the hot water flash tank 34 of this system is pressurized by the steam compressor 39, almost all the work performed by the back pressure steam turbine 48 is transmitted as steam energy generated in the heat pump.

  That is, in contrast to the comparative example, in this embodiment, the amount of heat pumped up using the engine hermetic circulating cooling water system 11 of the gas engine as a heat absorption source is almost the same as the comparative example. Although the same is true, the amount of heat generated by the exhaust heat recovery boiler 4 is recovered to the heat pump 22 by the back pressure steam turbines 45 and 48, and then almost all of the heat is sent to the customer.

  Here, in the present embodiment, the power consumption that is increased as compared with the comparative example is the power required to raise the head of the feed water pump 6 to the exhaust heat recovery boiler 4. However, the increase in power consumption for that purpose is about 1/50 of the amount of heat pumped from the cold heat source, and considering that the power generation efficiency of the gas engine power generation facility is about 50%, it hardly reduces the merit. . On the other hand, in the comparative example in which the refrigerant compressor 29 and the vapor compressor 39 are driven by an electric motor, the increase in power consumption reaches 2/3 of the amount of heat pumped up from the cold source, and the internal combustion engine of the present embodiment. It can be said that the merit of the exhaust heat recovery device of the engine is much greater.

  In addition to the comparative example of FIG. 2, even when the machine is driven by an internal combustion engine, the compressor, which is a heat pump component, drives the power saved by using the internal combustion engine instead of the electric motor. For this reason, it is necessary to supply power from the outside, so that the energy saving effect of this embodiment is great.

  If you just want to increase the amount of steam to the outside, hot water of about 90 ° C. is produced by heat exchange from the cooling waste liquid of the internal combustion engine without using a heat pump, and steam is further generated by an electric boiler or combustion boiler. However, even in these methods, if a combustion boiler is used, the amount of fuel used increases, and if an electric boiler is used, the amount of power used increases. Therefore, it can be said that the energy saving effect of this embodiment is great. .

  According to the present embodiment, the heat pump increases the amount of steam supplied to the consumer by pumping up the cold using the engine coolant of the internal combustion engine as the heat absorption source, and greatly reduces the amount of power consumed in the process. (Or the electric energy is made substantially zero).

  Another embodiment of the present invention is shown in FIG. In the above-described first embodiment, the back pressure steam turbines 45 and 48 that respectively drive the refrigerant compressor 29 and the steam compressor 39 inside the heat pump 22 are configured in parallel. Back pressure steam turbines 45 and 48 that respectively drive the refrigerant compressor 29 and the steam compressor 39 are configured in series. That is, in this embodiment, the superheated steam pipe 43 of the exhaust heat recovery boiler 4 is connected to the back pressure steam turbine 45 for the refrigerant compressor 29, and the steam turbine exhaust pipe 46 of the back pressure steam turbine 45 is connected to the steam compressor. The back pressure steam turbine 48 for 39 is connected. The steam turbine exhaust pipe 49 of the back pressure steam turbine 48 is connected to the steam supply header 50. The superheated steam that has exited the exhaust heat recovery boiler 4 along this route passes through the back-pressure steam turbine 45 and the back-pressure steam turbine 48 in this order, and is then guided to the steam supply header 50. The superheated steam exiting the exhaust heat recovery boiler 4, the back pressure steam turbine 48, and the back pressure steam turbine 45 may be worked in this order before being guided to the steam supply header 50.

  Also in the present embodiment, there is no change in the amount of heat pumped up using the engine hermetic circulating cooling water system 11 of the gas engine as a heat absorption source.

  Also in the present embodiment, in the same manner as in the first embodiment described above, the amount of steam supplied to the consumer is increased by pumping up the cold with the heat pump using the engine coolant of the internal combustion engine as the heat sink, and consumed in the process. It is possible to greatly reduce (or substantially reduce) the amount of power to be generated.

  In each of the above-described embodiments, the heat pump generates steam using the engine coolant of the internal combustion engine as a heat absorption source, but may be configured to generate steam using the lubricating oil of the internal combustion engine as a heat absorption source. Alternatively, steam may be generated using each of the engine coolant of the internal combustion engine and the lubricating oil of the internal combustion engine as a heat absorption source. When generating steam using each of the engine coolant of the internal combustion engine and the lubricating oil of the internal combustion engine as heat sinks, the heat may be absorbed by the same heat pump, or each of the engine coolant and the lubricating oil of the internal combustion engine by different heat pumps. The steam may be generated by absorbing heat. For example, when a plurality of internal combustion engines are installed, a back pressure steam turbine that drives a compressor inside a heat pump that absorbs heat from engine coolant using superheated steam generated by an exhaust heat recovery boiler of one internal combustion engine. And the back pressure steam turbine that drives the compressor inside the heat pump that absorbs heat from the lubricating oil of the internal combustion engine using the superheated steam generated in the exhaust heat recovery boiler of the other internal combustion engine. good.

  Further, in each of the above-described embodiments, the back pressure steam turbine is used to drive both the cooling compressor and the steam compressor, but any one of them can obtain an energy saving effect.

  Further, a back pressure steam turbine and an electric motor may be combined to drive the cooling compressor or the steam compressor. For example, it is conceivable to use a back pressure steam turbine as a main and use an electric motor as an auxiliary.

  In each of the above-described embodiments, the generator is driven by the internal combustion engine. However, the present invention can be similarly applied to a system that drives the machine by the internal combustion engine.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  In addition, the flow of water and steam, heat exchange, and the like are those that are considered necessary for the explanation, and not all the flow of water and steam, heat exchange, etc. are necessarily shown. In order to improve thermal efficiency and the like, various devices such as water and steam flow and heat exchange are performed.

DESCRIPTION OF SYMBOLS 1 ... Gas engine, 2 ... Generator, 3 ... Exhaust gas duct, 4 ... Exhaust heat recovery boiler, 5 ... Feed water pipe, 6 ... Feed water pump, 7 ... Charcoal saver heat transfer pipe, 8 ... Boiler drum, 9 ... Evaporator, DESCRIPTION OF SYMBOLS 10 ... Steam pipe, 11 ... Engine sealed circulation cooling water pipe, 12 ... Engine sealed circulation cooling water pump, 13 ... Engine sealed circulation cooling water cooler, 14 ... Engine sealed circulation cooling water temperature control valve, 15 ... Lubricating oil piping, 16 DESCRIPTION OF SYMBOLS ... Lubricating oil pump, 17 ... Lubricating oil cooler, 18 ... Lubricating oil temperature control valve, 19 ... Secondary cooling water piping, 20 ... Secondary cooling water pump, 21 ... Cooling tower, 22 ... Heat pump, 23 ... Engine hermetic circulation Cooling water heat exchanger, 24 ... heat pump evaporator, 25 ... heat pump heat absorption source circulation pump, 26 ... heat pump heat absorption source circulation piping, 27 ... heat pump heat absorption source water temperature control valve, 28 ... heat pump refrigerant circulation piping, 29 ... heat pump 30: heat pump refrigerant expansion valve, 31 ... heat pump refrigerant condenser, 32 ... heat pump refrigerant compressor drive motor, 33 ... heat pump hot water circulation piping, 34 ... heat pump hot water flash tank, 35 ... heat pump hot water circulation pump, 36 ... Heat pump make-up water pipe, 37 ... Heat pump make-up water pump, 38 ... Flash steam pipe, 39 ... Heat pump steam compressor, 40 ... Heat pump steam compressor drive motor, 41 ... Heat pump outlet steam pipe, 42 ... Waste heat recovery boiler superheater, 43 Exhaust heat recovery boiler superheated steam pipe, 44 ... Heat pump refrigerant compressor driving steam supply pipe, 45 ... Heat pump refrigerant compressor driving back pressure steam turbine, 46 ... Back pressure steam turbine exhaust pipe, 47 ... Heat pump steam compressor driving Steam pipe, 48 ... Back for heat pump steam compressor drive Steam turbine, 49 ... Back pressure steam turbine exhaust pipe, 50 ... Steam supply header, 51 ... Steam supply pipe, 52 ... Turbine bypass pipe, 53 ... Turbine bypass valve, 54 ... Temperature reducer, 55 ... Reduced temperature water supply pipe, 56 ... temperature control valve.

Claims (5)

An exhaust heat recovery boiler that recovers heat from the combustion exhaust gas of the internal combustion engine and generates steam; and a heat pump that generates steam using the lubricating oil or engine coolant of the internal combustion engine as a heat absorption source,
The exhaust heat recovery boiler is configured to generate superheated steam,
A back pressure steam turbine that uses superheated steam generated in the exhaust heat recovery boiler as driving steam as a driving source of a compressor that pressurizes the cooling medium or steam inside the heat pump;
An exhaust heat recovery apparatus for an internal combustion engine, wherein steam generated by the heat pump and exhaust steam of the back pressure steam turbine are supplied to a steam demand destination.   In Claim 1, the said back pressure type steam turbine is used as each drive source of the compressor which compresses the said cooling medium, and the compressor which pressurizes the said steam, The said exhaust heat recovery boiler is used for any one of the back pressure type steam turbines. The generated superheated steam is supplied, the exhaust steam of the one back pressure steam turbine is supplied to the other back pressure steam turbine, and the exhaust steam of the other back pressure steam turbine is supplied to the customer. An exhaust heat recovery device for an internal combustion engine characterized by the above.   In Claim 1, it has a path which branches from the middle of a path which supplies steam from the exhaust heat recovery boiler to the back pressure steam turbine, and bypasses the steam generated in the exhaust heat recovery boiler to the demand side, An exhaust heat recovery apparatus for an internal combustion engine, characterized in that a temperature reducer is installed in the path.   2. The exhaust heat recovery apparatus for an internal combustion engine according to claim 1, wherein the compressor that compresses the cooling medium or the compressor that pressurizes the steam is driven using an electric motor in addition to the back pressure steam turbine. An internal combustion engine, a generator driven by the internal combustion engine, an exhaust heat recovery boiler that recovers heat from the combustion exhaust gas of the internal combustion engine to generate steam, and a lubricating oil or engine coolant of the internal combustion engine as a heat absorption source Equipped with a heat pump that generates steam,
The exhaust heat recovery boiler is configured to generate superheated steam,
A back pressure steam turbine that uses superheated steam generated in the exhaust heat recovery boiler as driving steam as a driving source of a compressor that pressurizes the cooling medium or steam inside the heat pump;
A cogeneration system, wherein steam generated by the heat pump and exhaust steam of the back pressure steam turbine are supplied to a steam demand destination.

Images