Device and method for manufacturing dry ice by using liquefied natural gas cold energy

Abstract

The invention discloses a device and a method for manufacturing dry ice by using liquefied natural gas (LNG) cold energy. An outlet of a CO2 gas compressor is sequentially connected with a water cooler, a high-temperature passage of a propane heat exchanger, a high-pressure coiled tube of a low-temperature heat exchanger, a throttle valve, a dry ice collector, a filter screen, a stop valve, a low-pressure coiled tube of the low-temperature heat exchanger, a low-temperature passage of the propane heat exchanger, a check valve and an inlet of the CO2 gas compressor; a bypass valve is arranged between the stop valve and the check valve; a funnel is arranged below the dry ice collector; the outlet of a low-temperature pump is connected with the inlet of a low-temperature pump through the low-temperature passage of the propane heat exchanger and a shell pass of a natural gas heat exchanger; and liquefied natural gas is introduced into a tube pass of the natural gas heat exchanger. The LNG cold energy is applied to the production of the dry ice, the pressure at the outlet of the CO2 compressor can be reduced from 2MPa when the LNG cold energy is not used to below 1MPa, so that the power consumption of the compressor can be reduced by over 1 / 3. The method accords with the general trend of saving energy, reducing consumption and developing circular economy and has obvious environmental benefit and economic benefit.

Description

technical field [0001] The invention relates to the technical field of energy saving and refrigeration engineering, in particular to a dry ice production device and method thereof utilizing the cold energy of liquefied natural gas. Background technique [0002] As a high-quality energy source, natural gas has the advantages of low pollution, abundant reserves, and high calorific value per unit mass. However, the production and consumption places of natural gas are often different, so natural gas is liquefied into liquefied natural gas (LNG) at low temperature (about 112K) and then transported to the receiving terminal at the destination by LNG ship. At the receiving terminal, in order to meet the requirements of pipeline transportation, LNG needs to be heated to room temperature through heat exchange and vaporization with seawater. The heat value released during the vaporization and heating process of LNG is about 840kJ / kg, and this part of energy is taken away by seawater,...

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Problems solved by technology

[0006] None of the above-mentioned patent application descriptions relates to a device for producing dry ice using the cold energy of LNG

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