Precooling method for infiltrative type low-temperature liquid pump

Abstract

The invention discloses a precooling method for an infiltrative type low-temperature liquid pump. The method comprises the following steps of: (1) preparing two storage tanks between which a pressure difference exists, wherein the storage tanks are connected in series with the infiltrative type low-temperature liquid pump through a pipeline and a valve body arranged on the pipeline respectively; (2) opening the valve, feeding a low-temperature liquid into a low-pressure storage tank from a high-pressure storage tank by the infiltrative type low-temperature liquid pump while precooling the infiltrative type low-temperature liquid pump; and (3) when the temperature of the infiltrative type low-temperature liquid pump falls below a usage temperature according to display of a computer, which indicates that the infiltrative type low-temperature liquid pump is pre-cooled fully and can be put into use, starting the infiltrative type low-temperature liquid pump. Compared with the conventional precooling technology for an infiltrative type low-temperature liquid pump, the precooling method has the advantages that waste caused by precooling of the infiltrative type low-temperature liquid pump through low temperature dissipating liquids (such as substance which are gaseous at the normal temperature including liquefied natural gas and liquefied coal gas) is avoided, the precooling time is shortened, energy and precooling time are saved, the safety coefficient is increased, and the production cost is lowered.

Description

technical field [0001] The invention relates to a precooling method, in particular to a precooling method for an immersion cryogenic liquid pump used for transporting cryogenic liquid. Background technique [0002] In the process of using liquefied natural gas (LNG), in order to input low-pressure natural gas into high-pressure natural gas pipeline network or gas tank, submerged cryogenic liquid pumps (hydrocarbon pumps) are required for pressurized delivery. Since the immersion cryogenic liquid pump is at normal temperature and pressure before use, the natural gas in the pump is in a gaseous state, and the hydrocarbon pump can only pressurize and transport liquid natural gas, so the immersion cryogenic liquid pump must be pre-cooled to reduce It can only work under the condition of natural gas liquid, that is, below -100°C. At present, the pre-cooling technology of immersion cryogenic liquid pump is to use three divergent pipes on the top of the hydrocarbon pump. Through t...

AI Technical Summary

Problems solved by technology

With this technology, it takes about 40 minutes from the beginning of pre-cooling to normal operation. During this period, a large amount of natural gas needs to be released, which not only causes energy waste and air pollution, but also easily causes safety accidents.

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