JPH0231523Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention generates hot water/steam by scavenging air from an internal combustion engine and recovering waste heat from exhaust gas, and then supplies the steam to a turbo generator to generate electricity. This relates to a hydrothermal flash power generation system.

BACKGROUND ART Conventionally, a hot water flash power generation system has been known as an effective method for waste heat recovery from internal combustion engines, particularly for waste heat recovery systems in ships. This mainly recovers the main engine scavenging air energy to heat the feed water to the exhaust gas economizer, recovers the main engine exhaust gas energy to generate high-pressure steam, intermediate-pressure steam, and hot water, and then sends the hot water to a multi-stage flusher. multi-stage low-pressure steam is generated through vacuum evaporation.

The system uses a portion of the intermediate-pressure steam to heat the ship as required, and then directs high-pressure, intermediate-pressure, and multi-stage low-pressure steam to a mixing turbine to generate electricity.

Problems to be solved by this idea However, in the conventional system, the waste heat of the main engine jacket is not utilized, and the main engine scavenging air energy is currently used only for heating the water supply to the exhaust gas economizer. The waste heat recovery efficiency was low compared to the total amount of heat generated.

For this reason, the output power from the turbo generator is relatively low, and only a relatively high-output main engine can provide enough power for the ship, and an auxiliary power generation system may be required for small to medium-output main engines. It was hot.

Therefore, an object of the present invention is to improve the disadvantages of the conventional hot water flash power generation system as described above, and to provide a flash power generation system that can further improve waste heat recovery efficiency and realize energy savings.

A further object of the present invention is to increase the amount of steam generated in the flusher by using thermal energy recovered from waste heat from both the coolant of the internal combustion engine and the scavenging gas, thereby increasing the amount of power generated by the turbo generator.

Composition of the invention The hydrothermal flash power generation system according to the invention is
The working fluid passing through the jacket liquid cooling cycle of the internal combustion engine is recycled to one side of the multi-stage flusher to recover jacket waste heat, and the working fluid that has recovered energy from the scavenging air in the scavenging air cooler of the internal combustion engine is recycled to the multi-stage flusher. The system is characterized by recovering waste heat from the scavenging air, thereby increasing the amount of steam generated within the flusher and feeding it to the turbo generator, improving heat recovery efficiency.

Embodiments Hereinafter, a hot water flash power generation system according to the present invention will be described with reference to illustrated embodiments.

Figure 1 shows a system diagram of a system in which the present invention is applied to a diesel engine of a ship.

In this system, to diesel engine 1,
Scavenging air is supplied via the main engine air cooler 2. This air cooler 2 cools air that is normally around 140°C to around 45°C. Further, the exhaust gas from the diesel engine 1 is normally around 250°C, and is sent to the exhaust gas economizer 4.

On the other hand, a drain tank 20 and a condenser 1, which will be described later,
Water from 7 is supplied to the high temperature section of the main engine air cooler 2 by a condensate pump 16 and a water supply pump 3. Cooling water heated to about 120° C. by heat exchange with the air sent to the main diesel engine 1 in the main engine air cooler 2 is sent to a low pressure flasher 9 constituting one of the multistage flashers. This low-pressure flasher 9 is heated by the water supplied from which scavenging waste heat has been recovered by the main engine air cooler 2, and the amount of low-pressure steam generated from medium-pressure saturated water that is separately supplied increases.

The water that has passed through the low-pressure flusher 9 becomes hot water at about 90° C. and is sent to the exhaust gas economizer 4. Here, by controlling the three-way valve 24 and valve 23 provided at the connecting part of the pipe connecting the main engine air cooler 2, the low-pressure flusher 9, and the exhaust gas economizer 4, the exhaust gas economizer can be directly connected to the water supply pump 3. It is also possible to feed cooling water to the 4 side.

Here, the exhaust gas economizer 4 includes a preheating section 4A,
Medium pressure evaporation section 4B, high pressure evaporation section 4C and superheating section 4D
It is a two-stage pressure type, and the water supplied from the low pressure flusher 9 is fed to the preheating section 4A at a temperature of about 90°C.

The feed water preheated to a certain degree in the preheating section 4A is sent to the medium pressure evaporation section 4B and the high pressure separation drum (or auxiliary boiler) 5 through the valve 26. High-pressure drain is fed from this high-pressure separation drum 5 to a high-pressure evaporator 4C by a boiler water circulation pump 6, and is turned into high-pressure steam and refluxed to the high-pressure separation drum. Further, this high-pressure steam is supplied from the high-pressure separation drum 5 to the superheating section 4D and the necessary heaters 18' in the ship. The high-pressure steam that has flowed into the superheating section 4D exchanges heat with the exhaust gas to become superheated high-pressure steam and is supplied to the turbo generator 8.

On the other hand, the hot water fed to the medium pressure evaporator 4B becomes medium pressure steam and is fed to the medium pressure separation drum 7, where it is separated into medium pressure saturated steam and medium pressure saturated water, which is a medium pressure drain. . Here, the medium-pressure saturated steam is fed to the turbo generator 8 and the necessary heater 18 on board, and the medium-pressure drain is fed to the low-pressure flasher 9 and the low-low-pressure flasher 10 (described later) to become low-pressure and low-low-pressure steam, respectively. and is guided to the turbo generator 8. The exhaust steam from the turbo generator 8 turns into water in the condenser 17 and returns to the condensate pump 16.

Further, drain from the inboard heaters 18, 18' is sent to the hot well portion of the condenser 17 via a drain cooler 19 and a drain tank 20.

Here, a low-low-pressure flasher 10 constituting the other side of the multi-stage flasher is provided to recover waste heat from the jacket, and cooling water is supplied through the inside of the jacket by a main engine jacket cooling water pump 11. The jacket is configured to provide waste heat recovery. The cooling water from which this jacket waste heat is recovered is also supplied to the water generator 13, and the amount of cooling water passing through the water generator 13 can be adjusted by a throttle valve 21. Further, the cooling water flowing back from the low-low pressure flusher 10 and the fresh water generator 13 is sent out via the main engine jacket cooler 14 or directly to the main engine jacket cooling water pump 11 by the three-way valve 22. Here, the cooling water is automatically controlled by the three-way valve 22 so that the main engine outlet jacket cooling water temperature is 85°C.

In the above configuration, the feed water pumped from the water pump 3 recovers waste heat from the main engine scavenging air in the main engine air cooler 2, a part of which is used to heat the low pressure flusher 9, and the rest is led to the exhaust gas economizer 4. .

The feed water is further heated in the preheating section 4A of the exhaust gas economizer 4, a part of which is guided to the medium pressure evaporation section 4B, and medium pressure steam and medium pressure drain are generated in the medium pressure steam separation drum 7. Here, the remainder of the feed water that has left the preheating section 4A enters the high-pressure separation drum 5 and is circulated through the high-pressure evaporation section 4C by the boiler water circulation pump 6, after which high-pressure steam is generated in the high-pressure separation drum 5. A part of the high pressure steam is used in the necessary heater 18' on board,
Most of it becomes superheated steam in the superheating section 4D and is guided to the turbo generator 8.

Further, the medium pressure saturated steam generated in the medium pressure steam separation drum 7 is mainly used for the necessary in-ship heater 18, but the rest is used for driving the turbo generator 8.

The medium-pressure drain (medium-pressure saturated water) generated in the medium-pressure steam separation drum 7 is led to the multi-stage flashers 9 and 10 and is depressurized to generate low-pressure, low-low-pressure steam.

Here, the low pressure flasher 9 is the main engine air cooler 2.
It is heated by the feed water from which scavenging waste heat is recovered, increasing the amount of steam generated. Further, the low-low pressure flasher 10 is heated by the main engine jacket cooling water from which main engine waste heat is recovered in the main engine cylinder jacket 12, and the amount of steam generated increases. In this way, the multi-stage flasher 9,
The steam generated at 10 is used to drive a turbo generator 8.

The exhaust gas from the turbo generator 8 is condensed in a condenser 17 and sent to the water supply pump 3 by a condensate pump 16. The low and low pressure drain (saturated water) generated in the low and low pressure flusher 10 is sent to the water supply pump 3 by the drain boost pump 15.

Further, drain from the inboard heaters 18, 18' is collected in a drain tank 20 via a drain cooler 19, and is led to a hot well portion of a condenser 17.

The main engine jacket cooling water is guided to the main engine cylinder jacket 12 by the main engine jacket cooling water pump 11, and after recovering the jacket waste heat, the low/low pressure flusher 10 and the fresh water generator 13 are heated. This cooling water is supplied to the main engine jacket cooler 14.
The water is guided to the main engine jacket cooling water pump 11 through the.

Figure 2 shows an example of the turbo generator output corresponding to the main engine output (normal output). In the figure, W1 indicates the turbo generator output corresponding to the conventional hot water flash power generation system, W2 indicates the turbo generator output of the hot water flash power generation system according to the present invention, and W3 indicates the required power in the ship.

In addition, the calculation conditions are: engine room temperature: 27℃, water generation device: 20T/DAY, exhaust gas temperature at the exhaust gas economizer inlet: 250℃, main engine jacket cooling water temperature at the engine outlet: 85℃, and air cooler outlet. The temperature of the water supply at the exhaust gas economizer inlet was 120℃, and the temperature of the water supply at the exhaust gas economizer inlet was 90℃.

As shown in the data shown in Figure 2, when the amount of water generated by the water generation device is 20T/day, the amount of electricity generated by the system of the present invention is increased by approximately 14% compared to the conventional system.

Of this 14%, approximately 10% is an increase due to main engine jacket waste heat recovery, and the remaining 4% is an increase due to main engine scavenging air waste heat recovery.

As a result, in the conventional system, the main engine output was approximately
The turbo generator used to be able to cover all of the onboard power required for 16,500 PS or more, but with this invention, it can now be provided for approximately 14,000 PS or more, increasing the energy-saving effect.

In this embodiment, the case where the present invention is applied to a main engine of a ship has been described, but the present invention is not limited to this and is also effective as a waste heat recovery system for an internal combustion engine used on land.

Effects of the invention The embodiments of the hot water flash power generation system according to the invention are as described above, and the following effects can be achieved.

In a hot water flash power generation system, thermal efficiency can be improved by recovering waste heat from the jacket and scavenging air of the internal combustion engine, and by feeding the steam generated by utilizing this waste heat to a turbo generator.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of the present invention. FIG. 2 is a generator output-main engine output diagram. 1... Diesel engine, 2... Main engine air cooler, 3... Water supply pump, 4... Exhaust gas economizer, 4A... Preheating section, 4B... Medium pressure evaporation section, 4C
...High pressure evaporation section, 4D ... Superheating section, 5 ... High pressure separation drum, 6 ... Boiler water circulation pump, 7 ... Medium pressure steam separation drum, 8 ... Turbo generator, 9 ...
Low pressure flasher, 10...Low low pressure flasher, 1
1...Main engine jacket cooling water pump, 18,1
8'... Required heater inside the ship, 19... Drain cooler,
20... Drain tank, 21... Throttle valve, 22
...Three-way valve, 23... Valve, 24, 25, 26...
Three-way valve.

Claims (1)

[Scope of Claim for Utility Model Registration] A hot water flusher equipped with a multi-stage flasher that scavenges air from an internal combustion engine and recovers waste heat from exhaust gas to generate hot water/steam and send the steam to a turbo generator to generate electricity. In the power generation system, the working fluid passing through the jacket liquid cooling cycle of the internal combustion engine is returned to one side of the multi-stage flasher to recover jacket waste heat, and the working fluid recovers energy from the scavenging air in the scavenging air cooler of the internal combustion engine. What is claimed is: 1. A hot water flash power generation system characterized in that the hot water flash power generation system is configured to perform scavenging waste heat recovery by circulating water to the other side of a multistage flasher.