A mixed working fluid throttling refrigerator working condition concentration control system and method thereof

Abstract

The invention discloses a mixed working medium throttling refrigerator operating condition concentration control system and a method thereof, comprising a compressor unit, a condensing cooler unit, a recuperation heat exchanger unit, a throttling unit, an evaporator unit, and a controllable passage Working fluid concentration and flow adjustment unit, control unit. Its input parameters are the compressor suction pressure and / or discharge pressure value of the refrigerator system, the inlet temperature value of the recuperator heat exchanger, the outlet temperature value of the recuperator heat exchanger, the inlet temperature value of the throttling unit, and the outlet temperature value of the throttling unit The temperature value, the outlet temperature value of the evaporator, and the output parameters are instructions for controlling the corresponding actions of the execution unit. Corresponding to the requirements of different operating conditions and capacity adjustment of the mixed working medium throttling refrigerator system, according to the comparison between the preset value and the input parameters, the circulating concentration of the working medium in the refrigeration system is adjusted through the controllable passage working medium concentration and the flow adjustment unit. Control and adjust to make it adapt to the operating requirements of different working conditions and maintain high operating efficiency.

Description

technical field [0001] The invention relates to the subject field of engineering thermophysics and energy utilization, in particular to a concentration control system and a method for working condition concentration of a mixed working medium throttling refrigerator. Background technique [0002] Using traditional vapor compression refrigeration technology, the minimum effective refrigeration temperature that can be achieved by a single-stage cycle is around -40°C. If you want to achieve a lower refrigeration temperature, you need to use multi-stage compression or multi-stage cascade cycle. In the existing technology, two-stage compression can achieve a refrigeration temperature of about -60°C, and a two-stage cascade cycle can achieve a refrigeration temperature of about -80°C, but to achieve a refrigeration temperature of -100°C or even lower, it is necessary to Take more than three levels of cascade loops. Therefore, as the demand temperature decreases, the refrigeration ...

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Problems solved by technology

[0003] However, due to the characteristics of the mixed working medium used in the mixed working medium throttling refrigeration technology, if the corresponding technical means are not used to control it, there will be some defects as follows: (1) The multi-component mixed working medium cryogenic refrigeration system, due to the use of Strong non-azeotropic working fluid, the working fluid in the condenser is basically exothermic in the gas phase, the outlet of the condenser has a certain dryness, and will not be overcooled

In this way, the efficiency of the system is ensured by adjusting the appropriate concentration. Generally speaking, the power of the system does not change much after adjusting the concentration, but the efficiency can be improved; instead of adjusting the concentration, just increasing the flow to increase the power may be due to changes in the concentration. , the refrigeration efficiency cannot be improved. Obviously, this method is not effective compared with adjusting the concentration and is not energy-saving

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