The low-temperature cold box is a set of low-temperature heat exchange equipment with high efficiency, heat insulation and cold preservation. Because low temperature is easy to dissipate cold and requires very strict heat insulation and cold preservation, the heat exchanger and separator are packed in a box with heat insulation materials.
It is understood that the low-temperature cold box technology has three key aspects, including heat transfer calculation, mechanical structure design and operational safety technology design.
The three should cooperate closely, with high efficiency, pressure resistance, material saving, small flow resistance and small heat (cold) loss, so as to ensure the efficient and safe operation of the equipment.
Some insiders said that the risk factors involved in the operation of the cryogenic cold box are complex, including the leakage of the internal process system of the cryogenic cold box, sealing the risk environment, etc., and there are certain security risks.
In view of the grim situation of low-temperature cold box design and safe operation, based on the requirements of controlling the safety risk factors of low-temperature cold box and promoting the healthy and sustainable development of low-temperature cold box industry, it is urgent for industry associations to speed up the formulation of relevant group standards for low-temperature cold boxes.
Recently, China Industrial Gas Industry Association's group standard "Technical Specification for Design and Operation Safety of Low Temperature Cold Box" and other group standards have been drafted for comments. In order to ensure the scientific and practical nature of the group standards, we are now open for comments.
Welcome relevant units or individuals to put forward valuable opinions. Please feed back your comments and suggestions to the Group Standards Technical Committee of China Industrial Gas Industry Association before March 6, 20021year.
The author understands that the group standard "Technical Specification for Design and Operation Safety of Cryogenic Cold Box" stipulates the technical requirements for design and operation safety of Cryogenic Cold Box, and provides relevant risk control measures according to the risk factors involved in operation.
In the design of low-temperature cold box, there are eight requirements in terms of insulation mode, cold box structure, pipeline in cold box, cold box foundation, bottom of cold box, instrument detection pipeline and small-caliber process pipeline, so as to ensure the normal, efficient and safe operation of equipment.
For the pipes in the cold box, welding type should be adopted, and mechanical joints (flanges, threads, etc.) should be avoided. ) to reduce the risk of gas medium leakage.
When mechanical joints are used, separate insulation compartments should be used for isolation, which is convenient for maintenance and repair.
However, at the bottom of the cold box, it is required to set temperature detection elements at the bottom of the rectification tower, main heat exchanger, subcooler and other equipment inside the cold box, and effectively fix the temperature detection elements to avoid accidental sliding.
In order to ensure the safe and efficient operation of low-temperature cold box, the specification requirements of cold box interlayer construction and installation, sealing gas source and sealing gas monitoring, operation and monitoring of process equipment in cold box, fault diagnosis, maintenance and other related items are essential.
Among them, the operation and monitoring of process equipment in the cold box should also meet the requirements of relevant standards such as Technical Specification for Safety of Low Temperature Air Separation Equipment, so as to improve the safe operation level of the low temperature cold box.