A multi-stage low-temperature waste heat recovery system based on supercritical carbon dioxide

Abstract

The invention discloses a multi-stage low-temperature waste heat recovery system based on supercritical carbon dioxide, including a supercritical carbon dioxide multi-stage waste heat recovery cycle system, and a new heat exchange system that provides cold sources for the entire system; the new heat exchange system includes The first-stage new heat exchanger is installed. The carbon dioxide in the low-temperature heat exchanger exchanges heat with the circulating cooling medium through the first-stage new heat exchanger, and the carbon dioxide from the first-stage new heat exchanger enters through the large temperature difference heat exchange unit. to the second-stage new heat exchanger, and conduct heat exchange with the circulating cooling liquid, and finally form a low-temperature carbon dioxide working fluid and return to the low-temperature heat exchanger for heat exchange with low-temperature flue gas, and carry out the next stage of circulation. The low-low temperature multi-stage waste heat recovery and utilization system with critical carbon dioxide as the working fluid, after heat exchange at 6 places in the first-stage regenerator, the high-temperature working medium is divided into two paths, which improves the efficiency of waste heat utilization.

Description

technical field [0001] The invention belongs to the field of waste heat recovery, and relates to a multi-stage low-temperature waste heat recovery system based on supercritical carbon dioxide. Background technique [0002] At present, waste heat power generation is a good way to solve energy recovery, which not only saves energy but also is beneficial to environmental protection. Waste heat power generation is mainly a technology that converts excess heat energy generated in the production process into electrical energy. According to the survey, the total waste heat resources of various industries account for about 17% to 67% of their total fuel consumption, and the recyclable waste heat resources are about 60% of the total waste heat resources. At present, high-temperature and medium-temperature waste heat can be recycled and utilized very well. The low-temperature waste heat recovery technology is complicated, and it is difficult to recover low-temperature waste heat. In ...

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Problems solved by technology

The system aims to solve the problems of a large amount of flue gas waste heat loss and the ineffective recovery and utilization of low-temperature waste heat due to the low efficiency of the regenerative heat exchanger in the existing waste heat recovery system and the waste heat is only used in a single stage.

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