Method and device for making ice by using liquefied natural gas cold energy

Abstract

The invention discloses a method and device for making ice by using liquefied natural gas cold energy. The method comprises the following steps that: (1) the liquefied natural gas with pressure of 0.3-0.5 MPa and temperature of -162 DEG C is kept at a temperature of 15-20 DEG C and a pressure of 0.3-0.5 MPa after exchanging heat with glycol aqueous solution, and then is gasified into the natural gas with pressure of 0.3-0.5 MPa and temperature of 25 DEG C; and the natural gas with pressure of 0.3-0.5 MPa and temperature of 25 DEG C enters a natural gas pipe network; (2) the glycol aqueous solution after heat exchange is cooled to -34 to -36 DEG C and supercharged to 0.3-0.5 MPa; and then the glycol aqueous solution exchanges heat with water; the water is condensed into ice; and the ice is scraped off; and (3) the glycol aqueous solution after exchanging heat with water returns to a room temperature glycol storage tank; the glycol aqueous solution in the room temperature storage tank is heated to 1-2 DEG C to be recycled. The method for making the ice by using the liquefied natural gas cold energy, disclosed by the invention, has the advantages of high LNG (Liquefied Natural Gas) cold energy utilization rate, no need of additional refrigeration power source during making ice and energy consumption conservation.

Description

technical field [0001] The invention discloses a method and a device for using LNG cold energy to make ice. Background technique [0002] LNG (liquid natural gas) is a low-temperature liquid mixture formed by natural gas deacidification, dehydration, and freezing and liquefaction in a low-temperature process. The production process consumes a lot of energy. The vaporization of 1 kg of LNG at the LNG receiving station needs to provide about 830 kJ of energy, that is, about 230 kWh per ton. [0003] If the LNG cold energy can be effectively recovered and utilized, it can save energy, reduce the pollution of the LNG vaporization process, reduce the price of gas supply in the downstream market, and improve the economic benefits of natural gas. Japan, the United States, Canada and other countries have long begun to study the utilization of LNG cold energy, such as seawater desalination, air separation, low-temperature crushing, ice making, power generation, etc. [0004] Judgin...

AI Technical Summary

Problems solved by technology

Therefore, the utilization of LNG cold energy is insufficient, and there is a lot of waste of low-temperature nitrogen

From the above analysis, it can be seen that the cold energy of LNG is used in the air separation process, the equipment and process are complicated, and the energy utilization efficiency is low

[0005] The use of LNG cold energy to generate electricity is rare in the world, and because the temperature of LNG is -162°C, the quality of cold energy is high, and it is directly used to drive power generation devices such as turbines, and its efficiency is low, and its energy utilization efficiency is only about 10%

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