Multilevel cascade type refrigerating system for large air-conditioning system

Abstract

The invention provides a multilevel cascade type refrigerating system for a large air-conditioning system. The multilevel cascade type refrigerating system for the large air-conditioning system comprises an ultralow-temperature refrigerating system, a low-temperature refrigerating system, normal refrigerating systems, a water system and air conditioner terminals. The ultralow-temperature refrigerating system carries out heat exchange with the low-temperature refrigerating system. The low-temperature refrigerating system carries out heat exchange with the air conditioner terminals or a plurality of normal refrigerating systems with different refrigerating working media after carrying out heat exchange with the ultralow-temperature refrigerating system. The normal refrigerating systems carryout heat exchange with the multiple air conditioner terminals respectively after carrying out heat exchange with the low-temperature refrigerating system. The air conditioner terminals carry out loopheat dissipation through the water system. The multilevel cascade type refrigerating system for the large air-conditioning system has the beneficial effects that subsystems can carry out be selectively connected with one another as needed, and carry out multiple times of heat exchange, gradient utilization of refrigeration capacity is achieved, and the requirements of different building regions and a multifunctional building on different refrigerating temperatures are met.

Description

technical field [0001] The invention belongs to the field of refrigeration, in particular to a multi-stage cascade refrigeration system used in large air-conditioning systems. Background technique [0002] Since hydrochlorofluorocarbon refrigerants will cause various environmental problems such as the greenhouse effect and do not meet the requirements of green development, with the promulgation of the "Montreal Agreement", it is imminent to study alternatives to HCFCs and related refrigeration technologies. [0003] As an environmentally friendly refrigerant, carbon dioxide has a GWP global warming potential of 1 and an ODP ozone layer depletion potential of 0, which is about one-thousandth of R134a refrigerant and R22 refrigerant. In addition, it has low kinematic viscosity and low compression ratio High cooling capacity per unit volume. At 0°C, the cooling capacity per unit volume is 1.58 times that of ammonia, 5.12 times that of R22 refrigerant, and 8.25 times that of R12...

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Problems solved by technology

[0004] Aiming at the functional defects of the prior art, the purpose of the present invention is to provide a multi-stage cascade refrigeration system for large-scale air-conditioning systems. When using carbon dioxide as its ultra-low temperature refrigerant, it can solve the problems of the current Or safety hazards and long-distance transportation problems in subcritical refrigeration areas, realize cascaded utilization of cooling capacity, and meet the needs of various building partitions or multi-functional buildings for different cooling temperatures

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