CN211900813U

CN211900813U - Air supercharging system of marine diesel engine

Info

Publication number: CN211900813U
Application number: CN202020337470.8U
Authority: CN
Inventors: 刘成波; 李茂忠; 严彦涛
Original assignee: Shandong Ocean Shipping Co ltd
Current assignee: Shandong Ocean Shipping Co ltd
Priority date: 2020-03-18
Filing date: 2020-03-18
Publication date: 2020-11-10
Anticipated expiration: 2030-03-18

Abstract

The utility model discloses a marine diesel engine air supercharging system, this system mainly include natural gas air intake system, turbocharging system, air cooling system. In a turbocharging system, the Rankine cycle is realized by using LNG cold energy and waste heat of cooling water of a cylinder sleeve of a diesel engine, and a gas compressor is driven to compress air through a steam turbine. In addition, in the air supercharging process, the air sequentially passes through two cooling processes, and the air compressed in the air compressor is cooled in the first air cooler and the second air cooler respectively, so that the supplied air is higher in density, and more air enters the marine diesel engine, and the power performance of the marine diesel engine is improved. The utility model discloses can not only realize the air boost of diesel engine, make full use of the used heat of LNG cold energy and boats and ships diesel engine cylinder liner cooling water moreover, improve the utilization ratio of boats and ships energy greatly, improve the economic benefits of boats and ships.

Description

Air supercharging system of marine diesel engine

Technical Field

The utility model belongs to the technical field of boats and ships, a marine diesel engine air supercharging system is related to.

Background

In the 21 st century, people face huge environmental pollution problems and the traditional energy exhaustion crisis, and energy conservation and emission reduction become the subject of development of the current era and are also the target and the direction of development of the ship industry. SO of New International Maritime Organization (IMO) antipollution convention_XAnd NO_XAnd the emission requirements of waste gas are higher and higher.

Compared with fuel oil, the price of the fuel oil is unstable and the combustion of the fuel oil emits a large amount of CO₂And SO_XThe market price of the harmful substances such as Liquefied Natural Gas (LNG) is stable and low, and the harmful substances such as sulfur, dust and the like are hardly generated after combustion, and the discharged CO is₂And NO_XLess. LNG is considered an extremely attractive alternative to fuel on ocean-going vessels, including tankers, bulk carriers, and container carriers, with an increasing number of vessels using LNG or hybrid (diesel/LNG) as fuel. LNG is a cryogenic liquid at-163 ℃, but it must be gasified and warmed to ambient temperature before being burned in the main power plant of the ship. In the process, about 860kJ/kg of cold energy is released from 1kg of LNG, and if the part of high-grade cold energy is utilized, the economic benefit of the ship is greatly increased.

In addition, how to increase the fresh air entering the marine diesel engine to improve the fuel utilization rate of the diesel engine is also a problem which people want to solve. Turbochargers are increasingly being used on modern diesel engines. Turbochargers compress fresh air prior to entering the cylinder by passing it through a turbine and then delivering it at a high density to the cylinder to participate in combustion at a relatively high pressure. The larger the air pressure entering the cylinder, the more the charge, the more the fuel mixed with the charge is fully combusted, the higher the utilization rate is, and the single-cylinder power of the diesel engine is increased.

Turbochargers can be classified into exhaust gas turbochargers, combined exhaust gas turbochargers, and combined turbochargers according to the supercharging mode. The exhaust gas turbocharger has a simple structure and is reliable in operation, the power of the diesel engine provided with the exhaust gas turbocharger system can be improved by 30-50%, the power performance of the diesel engine can be improved, the economy of the diesel engine is improved, and the application is wide.

Therefore, if the LNG cold energy is used for doing work, the compressor is driven to compress air, the air input of the marine diesel engine can be greatly improved, the fuel is combusted more fully, and the power performance and the economic performance of the diesel engine are greatly improved.

SUMMERY OF THE UTILITY MODEL

The utility model discloses problem to the aforesaid mentions provides a marine diesel engine air supercharging system. The system mainly comprises a natural gas inlet system, a turbocharging system and an air cooling system.

Wherein natural gas air intake system mainly includes: lightering pump, LNG fuel tank, booster pump, heater.

The turbocharging system mainly comprises: the low-temperature heat exchanger, the first circulating pump, the refrigerant heat exchanger, the steam turbine, the transmission shaft and the air compressor.

The air cooling system mainly comprises: high temperature heat exchanger, first air cooler, second circulating pump, second air cooler.

In a natural gas intake system, LNG is transported out from an LNG fuel tank under the action of a transfer pump, the LNG flows in a pipeline after reaching a proper pressure under the supercharging effect of a booster pump, then cold energy is released in a low-temperature heat exchanger and a high-temperature heat exchanger in sequence, and then natural gas is heated in a heater by using cylinder sleeve water, so that the natural gas can reach a specified temperature for entering a marine diesel engine for combustion.

In the turbocharging system, refrigerant 1 enters the refrigerant heat exchanger under the pressurization effect of the first circulating pump to exchange heat with cylinder liner water of the marine diesel engine, at the moment, the refrigerant 1 absorbs heat in the cylinder liner water, the state of the refrigerant can change, and in the process, the refrigerant 1 is changed from a liquid state to a gas state and reaches an overheating state. Then, the refrigerant 1 in an overheated state enters a steam turbine, huge steam pressure drives a transmission shaft to work, namely, the steam turbine outputs shaft work, so that a compressor is driven to compress air, then the gas refrigerant 1 which does work absorbs cold energy released by LNG in a low-temperature heat exchanger, at the moment, the refrigerant 1 is changed from a gas state to a liquid state, then the refrigerant 1 continuously enters a refrigerant heat exchanger to perform heat exchange under the action of a first circulating pump, and the cycle is repeated. In the turbocharging process, the Rankine cycle is realized by utilizing LNG cold energy and heat energy of cooling water of a cylinder sleeve of a marine diesel engine, the steam turbine is driven to do work through the refrigerant 1, and then the compressor is driven to work through the transmission shaft, so that the air compression process is realized.

In the air cooling system, shaft work output by the steam turbine is converted into volume change work of air in the air compressor under the action of the transmission shaft, at the moment, fresh air carried in unit volume is much, then the compressed air is cooled by seawater in the first air cooler, so that the purpose of cooling the compressed air is achieved, then the compressed air after being cooled for the first time absorbs cold in the second air cooler, and more fresh air is carried in unit volume at the moment. The cold energy in the second air cooler is carried by the refrigerant 2, the refrigerant 2 absorbs the cold energy of LNG from the high-temperature heat exchanger under the action of the second circulating pump, and then the cold energy is released to compressed air in the second air cooler, so that the air quantity entering the cylinder of the diesel engine is improved.

The utility model has the advantages that:

1. the utility model discloses in utilize LNG cold energy and diesel engine cylinder liner cooling water's used heat, realize rankine cycle, drive compressor compressed air through steam turbine. In this pressure boost process, the utility model provides a system has realized the utilization in a large number of LNG cold energy and used heat.

2. The utility model discloses in utilize LNG to supply with air cooling for the air pressure that the marine diesel engine supplied with is higher, and density is bigger, therefore the air that gets into the cylinder is more, and the burning of fuel is more abundant in the diesel engine, makes the power performance of diesel engine better.

3. The utility model discloses be used for the air boost with the LNG cold energy, both carried out rational utilization to LNG cold energy and cylinder liner water used heat, increased the fresh air admission volume of diesel engine cylinder again, and the system is simple, easily realizes, has extensive practical meaning.

Drawings

FIG. 1 is a schematic diagram of an air supercharging system for a marine diesel engine;

in the figure: 1. a lightering pump; an LNG fuel tank; 3. a high pressure pump; 4. a low temperature heat exchanger; 5. a high temperature heat exchanger; 6. a first circulation pump; 7. a refrigerant heat exchanger; 8. a steam turbine; 9. a drive shaft; 10, an air compressor; 11. a first air cooler; 12. a second circulation pump; 13. a second air cooler; 14. heating device

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

The air supercharging system of the marine diesel engine shown in fig. 1 mainly comprises a natural gas inlet system, a turbocharging system and an air cooling system.

Wherein natural gas air intake system mainly includes: lightering pump (1), LNG fuel tank (2), booster pump (3), heater (14).

The turbocharging system mainly comprises: the low-temperature heat exchanger (4), a first circulating pump (6), a refrigerant heat exchanger (7), a steam turbine (8), a transmission shaft (9) and a compressor (10).

The air cooling system mainly comprises: the high-temperature heat exchanger (5), a first air cooler (11), a second circulating pump (12) and a second air cooler (13).

The steam turbine (8) and the air compressor (10) are connected through a transmission shaft (9), and the two share the same transmission shaft (9), so that the purpose of synchronous rotation is achieved.

The refrigerant 2 shown in fig. 1 absorbs the cold energy of LNG from the high temperature heat exchanger (5) under the action of the second circulation pump (12), and then releases the cold energy to the compressed air in the second air cooler (13), thereby increasing the amount of air entering the cylinder of the diesel engine.

In the natural gas intake system, LNG comes out from an LNG fuel tank (2) under the action of a lightering pump (1), the LNG reaches proper pressure and flows in a pipeline under the supercharging action of a supercharging pump (3), then cold energy is released in a low-temperature heat exchanger (4) and a high-temperature heat exchanger (5) in sequence, and then natural gas is heated in a heater (14) by using cylinder sleeve water, so that the natural gas can reach the specified temperature for combustion of a diesel engine of a ship.

In a turbocharging system, a refrigerant 1 enters a refrigerant heat exchanger (7) under the supercharging effect of a first circulating pump (6) to exchange heat with cylinder jacket water of a marine diesel engine, at the moment, the refrigerant 1 absorbs heat in the cylinder jacket water, the state of the refrigerant can change, the refrigerant 1 changes from a liquid state to a gaseous state, then the gaseous refrigerant 1 enters a steam turbine (8), the steam pressure of the refrigerant 1 drives a transmission shaft (9) to work, namely the steam turbine (8) outputs shaft work, so that an air compressor (10) is driven to compress air, then the gaseous refrigerant 1 after acting absorbs cold energy released by LNG in a low-temperature heat exchanger (4), at the moment, the refrigerant 1 changes from a gaseous state to a liquid state, then the refrigerant 1 continues to enter the refrigerant heat exchanger (7) to exchange heat under the effect of the first circulating pump (6), and the cycle is repeated.

The refrigerant 1 absorbs heat in the refrigerant heat exchanger (7), the refrigerant 1 is changed from liquid state to gas state and forms superheated steam, then the refrigerant 1 which becomes the superheated steam does work on the steam turbine (8) in a volume change form and a kinetic energy form, the steam turbine (8) converts the work of gas on the steam turbine into shaft work and outputs the shaft work from the transmission shaft (9), so that the compressor (10) is driven to work, air is compressed, the quality of fresh air entering the marine diesel engine in unit volume is improved, and the output power of the marine diesel engine is further improved.

In the air cooling system, shaft work output by a steam turbine (8) is converted into volume change work of air in an air compressor (10) under the action of a transmission shaft (9), at the moment, fresh air is carried in a unit volume, then the compressed air is cooled by seawater in a first air cooler (11), so that the purpose of cooling the compressed air is achieved, then, the compressed air after being cooled for the first time absorbs cold in a second air cooler (13), and at the moment, more fresh air is carried in the unit volume.

The foregoing is merely a preferred embodiment of the present invention, and the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. The utility model provides a marine diesel engine air supercharging system which characterized in that: the system comprises a natural gas inlet system, a turbocharging system and an air cooling system;

wherein natural gas air intake system includes: the LNG fuel tank comprises a lightering pump (1), an LNG fuel tank (2), a booster pump (3) and a heater (14);

the turbocharging system comprises: the system comprises a low-temperature heat exchanger (4), a first circulating pump (6), a refrigerant heat exchanger (7), a steam turbine (8), a transmission shaft (9) and a compressor (10);

the air cooling system includes: the system comprises a high-temperature heat exchanger (5), a first air cooler (11), a second circulating pump (12) and a second air cooler (13);

2. The marine diesel engine air supercharging system of claim 1, wherein: in the turbocharging system, a refrigerant 1 enters a refrigerant heat exchanger (7) under the supercharging action of a first circulating pump (6), exchanges heat with the cylinder water of the marine diesel engine, at the moment, the refrigerant 1 absorbs the heat in the cylinder water, the state of the refrigerant 1 changes from liquid state to gas state and reaches an overheat state, then the refrigerant 1 in the overheat state enters a steam turbine (8), the huge steam pressure drives the transmission shaft (9) to work, namely the steam turbine (8) outputs shaft work, thereby driving the air compressor (10) to compress air, then the gas refrigerant 1 after applying work absorbs the cold energy released by the LNG in the low-temperature heat exchanger (4), the refrigerant 1 changes from gas state to liquid state, and then the refrigerant 1 continuously enters the refrigerant heat exchanger (7) for heat exchange under the action of the first circulating pump (6), and the circulation is repeated.

3. The marine diesel engine air supercharging system of claim 1, wherein: a compressed air outlet in the air compressor (10) is connected with an air inlet of a first air cooler (11) through a pipeline, an air outlet of the first air cooler (11) is connected with an air inlet in a second air cooler (13) through a pipeline, the first air cooler (11) is cooled by seawater, and the second air cooler (13) is cooled by a refrigerant 2.

4. The marine diesel engine air supercharging system of claim 1, wherein: the refrigerant 2 absorbs the cold energy of the LNG from the high-temperature heat exchanger (5) under the action of the second circulating pump (12), then releases the cold energy to the compressed air in the second air cooler (13), and then continues to circulate repeatedly under the action of the second circulating pump (12).