生物技术行业中的低温冷藏设备通常使用复叠制冷，以达到-80℃（-112℉）或更低的蒸发温度。目前的系统使用多个压缩机，导致高能耗。设备运营成本在生物技术公司的总运营成本中占很大比例，因此推动了更高效的低温制冷替代品的开发。本文介绍了一种单压缩机R-23/R-134a混合制冷剂循环，该循环设计用于抽取0。 256kW（873.5 Btu/hr），在-80°C（-112°F）的条件下从一个有条件的空间发射。设计的系统将气体制冷剂的混合物压缩到高压，然后在水冷分离器中冷凝R-134a，而R-23保持在汽相。液体R-134a流膨胀至吸入压力，用于冷凝仍处于汽相的R-23，其运行方式与级联循环中的级间热交换器非常相似。R-23的冷凝流随后膨胀至吸入压力，并进入低温蒸发器，在那里吸收负载的能量。 根据热力学第一定律和第二定律原理建立了循环模型，并用于改进混合制冷剂试验装置的设计。原型系统的理论分析预测，当其以33.4%的R-23和66.6%的R-134a（按质量计）的混合物运行时，其蒸发温度将达到-78.6℃（-109.5℉）。在使用相同冷凝温度和混合物成分进行的实验中，混合制冷剂设备达到了-75.0°C（-103°F）的蒸发温度，与预测温度-78非常接近。 6摄氏度（-109.5华氏度）。为了达到-80°C（-112°F）的理想蒸发温度，必须对制冷剂混合物进行过滤，以增加R-23的量。引文:美国丹佛市ASHRAE会议论文

Low temperature refrigeration storage equipment in the biotechnology industry typically uses cascade refrigeration toachieve evaporating temperatures of -80 °C (-112 °F) or below. Current systems utilize multiple compressors leading tohigh energy consumption. Equipment operating costs contribute significantly to the total operating costs of biotechnologycompanies and therefore motivate the development of more efficient alternatives for low temperature refrigeration. Thispaper describes a single compressor R-23/R-134a mixed refrigerant cycle that has been designed to extract a load of 0.256kW (873.5 Btu/hr) from a conditioned space at -80 °C (-112 °F). The designed system compresses a mixture of thegaseous refrigerants to a high pressure and then condenses the R-134a in a water-cooled separator while the R-23 remainsin vapor phase. The stream of liquid R-134a is expanded to the suction pressure and is used to condense the R-23 thatremains in vapor phase, operating much like an inter-stage heat exchanger in a cascade cycle. The condensed stream of R-23 then expands to the suction pressure and enters a low-temperature evaporator, where it absorbs energy from the load.A model of the cycle is developed based upon first and second law principles of thermodynamics and used to refinethe design of a mixed refrigerant test apparatus. Theoretical analysis of the prototype system predicts that it will reach anevaporating temperature of -78.6 °C (-109.5 °F) when it operates with a mixture of 33.4% R-23 and 66.6% R-134a by mass.In experiments conducted using the same condensing temperature and mixture composition the mixed refrigerantapparatus reached an evaporating temperature of -75.0 °C (-103 °F), corresponding closely to the predicted temperature of-78.6 °C (-109.5 °F). To reach the desired evaporating temperature of -80 °C (-112 °F) the refrigerant mixture must bealtered to increase the amount of R-23.