A method for realizing high-efficiency and zero-pollution operation of liquefied natural gas-powered ship engines

Abstract

The invention discloses a method for achieving efficient zero-pollution running of a liquefied natural gas ship engine. The method comprises the following steps that natural gas and oxygen pass through a sea water preheater, after entering a combined pressure regulation gas distributing device, the natural gas, the oxygen and argon are conveyed to a combustion chamber of the engine for combustion, and exhausted gas of the combustion chamber of the engine passes through a waste heat recovery device and a sea water precooler for waste heat recovery; one part of exhausted gas generated after waste heat recovery enters a main channel, the other part of the exhausted gas enters a bypass channel at the upstream supporting point of the bypass channel communicating with the main channel, and then nitrogen and sulfur are removed; and the exhausted gas subjected to nitrogen and sulfur removal treatment returns to the main channel from a one-way valve at the downstream supporting point of the bypass channel, and enters a water cooling separating device and a carbon dioxide cooling separating device together with gas in the main channel, and gas with argon as the main component in gas left in the exhausted gas enters the combined pressure regulation gas distributing device. According to the method, the reasonable combustion speed is kept, and nitric oxide generated in the combustion process of an existing engine is avoided.

Description

technical field [0001] The invention relates to the fields of high-efficiency clean combustion and high-efficiency energy utilization of internal combustion engines, in particular to a method for realizing high-efficiency and zero-pollution operation of liquefied natural gas-powered ship engines. Background technique [0002] Two-stroke large-scale low-speed diesel engines have the characteristics of low fuel consumption, stable output torque, and low fuel quality requirements, and have been widely used in the three main ocean-going ships (oil tankers, container ships, and bulk carriers). However, with the deterioration of the earth's environment, the International Maritime Organization and many countries have formulated increasingly stringent regulations on marine emissions, and strict regulations on NOx and SOx emissions from ship engines. Compared with diesel or heavy oil, natural gas has lower sulfur content, more complete combustion, and no particulate matter emissions....

AI Technical Summary

Problems solved by technology

The problem with this method is that it does not indicate how to effectively utilize the cold energy of the generated liquid oxygen and liquid nitrogen, nor does it explain how to effectively use the cold energy of LNG to become natural gas after being utilized.

The problem with this method is that the temperature of LNG is much lower than that of liquid carbon dioxide. The method of directly using LNG to cool carbon dioxide gas to produce liquid carbon dioxide cannot efficiently utilize the cold energy of LNG. At the same time, the patent only describes the preparation process of liquid carbon dioxide, and does not explain the cooling of LNG. How to make effective use of natural gas after it can be utilized

The problem is that it does not indicate how to effectively use the cold energy of liquid oxygen and liquid nitrogen produced, nor how to effectively use the cold energy of LNG to become natural gas after being utilized.

The problem is that this paper only considers the waste heat recovery of engine exhaust, and does not propose a good treatment method for exhaust pollutants

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