Natural gas processing systems for marine engines

Abstract

The invention discloses a natural gas processing system for a marine engine, comprising a storage tank for storing natural gas, a gasification pipeline, a suction pipeline and a reliquefaction pipeline. The reliquefaction pipeline is provided with a compressor and a corresponding heat exchanger respectively. When the external engine needs to use natural gas fuel, the reliquefaction function can be turned off. When the external engine does not need natural gas fuel, if there is relatively If there is less excess natural gas, only one compressor can be operated to provide weak reliquefaction capacity and reduce operating energy consumption. Liquefaction capacity to ensure safe operation of storage tanks. Therefore, it can better match the changes of the external ambient temperature, so that the entire natural gas processing system can operate with the lowest possible power consumption.

Description

technical field [0001] The present invention relates to a natural gas processing system, more specifically a natural gas processing system for marine engines. Background technique [0002] Because natural gas is economical and environmentally friendly, it is widely used in modern ships. In order to reduce the space occupied by natural gas, natural gas usually needs to be pressurized and cooled and stored in liquid form in storage tanks. When ship engines use natural gas fuel , and then gasify the liquid natural gas into a gaseous state. In addition, since the storage tank for storing natural gas cannot be completely insulated from the outside world, the liquid natural gas in the storage tank will continuously absorb the external heat and gasify. When the gasified natural gas continues to increase, the pressure in the storage tank also increases. It will gradually increase, and part of the gaseous natural gas must be released after the safety pressure is exceeded, which is n...

AI Technical Summary

Problems solved by technology

In addition, because the storage tank for storing natural gas cannot be completely insulated from the outside world, the liquid natural gas in the storage tank will continuously absorb the heat from the outside and gasify. When the gasified natural gas continues to increase, the pressure in the storage tank will also increase It will gradually increase, and part of the gaseous natural gas must be released after the safe pressure is exceeded. This is not only unsafe, but also loses a lot of natural gas. Therefore, the natural gas storage tank must also be equipped with a reliquefaction system, which can convert the gaseous natural gas in the storage tank. natural gas reliquefaction

[0003] However, the natural gas supply system and the reliquefaction system of the marine engine in the prior art operate independently, and the ship often sails around the world, and the temperature difference of its external environment is also large. For example, when the ship is near the equator of the earth, the outside The ambient temperature is higher, and the gasification rate of the liquid natural gas in the storage tank is faster; while the ship is at the south pole of the earth, the temperature of the external environment is lower, and the gasification rate of the liquid natural gas in the storage tank is slower

The gasification speed of the liquid natural gas in the storage tank is the load of the ship's natural gas reliquefaction system. The faster the gasification speed, the larger the load of the reliquefaction system; the slower the gasification speed, the smaller the load of the reliquefaction system. As a result, state-of-the-art reliquefaction systems rarely operate at their optimum efficiency

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