JPS5853608A - Waste heat utilizing system in diesel engine - Google Patents

Abstract

PURPOSE:To increase thermal recovery efficiency in such a way that steam which is generated in a flush tank installed in a circulation cycle for cylinder cooling water is heated under pressure in an exhaust gas boiler, and the steam is induced into a mixed pressure turbine. CONSTITUTION:A waste heat utilizing system in a Diesel engine 1 provides a waste gas boiler 5, a mixed pressure turbine 10, and a condenser 11. Cylinder cooling water W is induced into a flush tank 13, and a large amount of saturated steam is generated. The saturated steam is induced into a heating part 15 which is installed on a waste gas boiler 5, and after it is made into heated steam, it is fed into the mixed pressure turbine 10, and effectively recovered as power. Thus, since it can utilize not only exhaust gas in the Diesel engine, but also waste heat in the cylinder cooling water, effective power can be obtained.

Description

[Detailed description of the invention] The present invention relates to a diesel engine exhaust heat utilization system.

In order to save energy by effectively utilizing the exhaust heat of a diesel engine, it has traditionally been the practice to generate steam in an exhaust gas boiler and use this steam to power a turbo generator. On the other hand, although the amount of heat radiated to the cylinder cooling water of a diesel engine is extremely large, it has not been effectively utilized because the cooling water temperature is as low as around 80°C. However, a medium-speed diesel engine with a cooling water temperature of around 130° C. at the engine outlet has been proposed, and conditions have been established for effectively utilizing the waste heat of the cylinder cooling water.

An object of the present invention is to utilize not only the exhaust gas of a diesel engine but also the waste heat of cylinder cooling water to obtain a large amount of steam to drive a turbine and obtain advantageous power.

In the present invention, medium-high pressure superheated steam is obtained in an exhaust gas boiler, while cylinder cooling water is led to a flash tank to generate low-pressure saturated steam, which is converted into superheated steam in the exhaust gas boiler and used together with the medium-high pressure superheated steam. Mixed pressure turbine #4
I'm trying to get power from it.

An embodiment of the present invention will be described below based on the drawings. In FIG. and second
This is done via a cooler (4). The waste gas (G) is passed through the drive turbine section (2a) of the supercharger (2) and the waste gas boiler (5).
) and is released into the atmosphere. The waste gas boiler (5)
The saturated steam heated and evaporated in the evaporator section (6) enters the steam/water separator (7), and the saturated steam is heated in the heating section (8) in the waste gas boiler (5) and becomes heated steam. Introduced to far pressure turbine 4. The waste steam discharged by driving the mixed pressure turbine αΦ enters the condenser (6)K, and the condensed water passes through the pump (to)K, enters the first cooler (3), and is sent to the supply air condenser. After being cooled and preheated, it is sent to the steam/water separator (7). The thin ice stored at the bottom of the steam/water tank (7) is sent to the evaporator (6)K by the pump (9)K, and thereafter circulated as described above. Through the above cycle, the thermal energy of the waste gas (G) is transferred to the evaporation section (6) and the heating section (8).
It is recovered and used to assist the mixed pressure turbine αQ. In such a waste heat utilization system, in order to effectively utilize the exhaust heat of the cylinder cooling water of the diesel engine (1), the cylinder cooling water (b) that has exited the diesel engine (1) is stored in a flash tank (to). , generates large amounts of saturated steam. The water cooled by steam generation is sent to the diesel engine (1) K by a pump (b) to cool the cylinder, and the heated cooling water is pumped into the flash tank (to).
! It is circulated. The saturated steam generated in the 7-ratchet tank (to) is introduced into the waste gas boiler (5) to the KR heating section (to), where it is converted into heated steam and then sent to the mixed pressure turbine αQ, where it is effectively recovered as motive power. be done.

Note that, since the saturated steam has a low temperature, the heating section (a) is arranged at the highest temperature section of the waste gas boiler (5) to prevent sulfuric acid corrosion. # Condensed in condenser 0υ
A part of the condensed water, that is, an amount of condensed water corresponding to the amount of steam generated in the flash tank (to) is returned to the cylinder cooling water circulation cycle aη through the return flow path (to). (To)
is a pressurized tank for the flash tank.

Note that the condenser QD and II2 cooler (4) are cooled with external cooling fluid such as seawater. In addition, in the illustrated example, only one stage of a 7f-length circuit is provided, which consists of an evaporation section (6), a steam/moisture WI device (7), and a heating section (8) for obtaining medium-high pressure heated steam using waste gas (iG). However, it is also possible to provide two stages, one for high pressure and one for intermediate pressure, and heat steam generated from each stage to be fed into the mixed pressure turbine.

The power obtained by the mixed pressure coupin αq is used to drive a generator to obtain electric power, or in the case of a marine diesel engine, is used to boost the propulsion shaft. For example, as shown in Figure 2, 1
In a marine diesel engine, the output shaft of the diesel engine (1) is connected to the propulsion shaft (e) via the reducer t2D, and the main shaft drive generator is connected to the reducer t2D. Connect the pressure turbine QO to the reducer (c). By doing this, the output of the diesel engine (1) is used to generate the generator (
2) to meet the necessary electrical power on board, while also utilizing the assistance of the mixed pressure turbine (to) to assist the propulsion shaft members. II (1) Aim to reduce fuel consumption. This is an effective self-blading utilization system in cases where when the generator (2) is driven by the mixed pressure turbine aO, more power than is required on board the ship is obtained, and the power is wasted.

According to the diesel exhaust heat utilization system of the present invention,
As is clear from the above explanation, it is possible to recover and use the waste heat of the 1 shilling cooling water as part of the power of the mixed pressure turbine, and moreover, the heated cylinder cooling water is led to the flash tank to directly generate saturated steam. Because of this, a large amount of saturated steam can be efficiently obtained and the heat recovery efficiency is high.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a flowchart of an exhaust heat utilization system, and FIG. 2 is a configuration diagram of a ship propulsion engine section using the system according to the present invention. (1)... Diesel engine, (5)... Waste gas boiler, (6)... Evaporation section, (7)... Steam water separator, (
8)... Heating section, al... Mixed pressure turbine, aυ...
・Condenser, (to)...7 Lassie tank, aθ...
Heating Department Agent Yoshihiro Morimoto Figure 1 Figure 2

Claims (1)

[Claims] 1. In an exhaust heat utilization system for a diesel engine equipped with an exhaust gas boiler, a mixed pressure turbine, and a condenser, a flash tank is installed in the cylinder cooling water circulation cycle of the diesel engine, and the saturated steam generated in the flash tank is converted into heated steam. An exhaust heat utilization system for a diesel engine, characterized in that a heating section is provided in the exhaust gas boiler, and heated steam from the heating section is introduced into the mixed pressure turbine.