Thermoacoustic system capable of gradually recovering LNG (liquefied natural gas) cold energy

Abstract

The invention discloses a thermoacoustic system capable of gradually recovering the LNG (liquefied natural gas) cold energy, which comprises a plurality of thermoacoustic engines, a low-grade heat energy supply system and an LNG cold energy supply system. The thermoacoustic engines are standing wave thermoacoustic engines, pure travelling wave thermoacoustic engines or piston phase-modulation thermoacoustic engines. The LNG cold energy supply system is connected with cold end heat exchangers of the thermoacoustic engines sequentially through pipelines, and the low-grade heat energy supply system is connected with hot end heat exchangers of the thermoacoustic engines through pipelines respectively. The temperature grade is built in a heat regenerator, the thermoacoustic effect is utilized to generate pressure fluctuation, the cold energy is transferred to the mechanical energy for outputting, and the high efficiency recovering of the cold energy is realized. Compared with the conventional LNG cold energy recovering manner, the multi-grade thermoacoustic system provided by the invention has a simple structure, eliminates mechanical moving parts, is low in cost and reliable in running, and adopts the multi-grade arrangement for recovering the LNG cold energy with a high cold energy recovering and utilizing rate.

Description

technical field [0001] The invention relates to the field of thermoacoustic technology, in particular to a thermoacoustic system capable of recovering the cold energy of liquefied natural gas in stages. Background technique [0002] Natural gas is a high-quality energy source, which has the characteristics of high calorific value, cleanliness, and low combustion pollution. In order to facilitate large-scale storage and transportation, natural gas is usually liquefied at low temperature (below 110K) into a liquid state (that is, Liquefied Natural Gas, LNG). When used, LNG is converted into a normal temperature gas, and a large amount of cold energy is released at the same time. The cold energy released during the vaporization of each ton of LNG is equivalent to about 250 kWh of electricity. Based on this calculation, a 3 million tons / year LNG receiving terminal can use about 750 million kWh of cold energy per year, which is equivalent to the annual power generation of 150,00...

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Problems solved by technology

Due to the influence of many factors such as the location of the LNG receiving station, the temperature requirements of the utilization process, the processing technology, and the economy, the above-mentioned LNG cold energy utilization methods still have problems such as high cost and complex structure, and it is difficult to utilize LNG cold energy in stages. The recovery rate is not high, so some new technologies and means are urgently needed to improve the recovery rate and economy of LNG

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