Next generation R744 refrigeration technology for supermarkets.

Supermarket refrigeration units of the future have to be able to handle the entire energy flows and demands in the supermarket building. Besides providing the cooling capacity for medium and low temperature display cabinets, the heat pumping demands of the HVAC units should be integrated into the requirement specification. This will reduce total investment and service costs. It will also reduce the total energy consumption due to the possibility of direct utilization of surplus heat and advanced capacity controls during AC mode. Therefore the system architecture of R744 commercial refrigeration unit has to be adapted to be able to fulfil the required duties as energy efficient as possible, i.a. the control of evaporation temperatures and evaporator outlet conditions at low, medium and AC temperature level. Integration of auxiliary evaporators for heat pump & AC operation will be discussed and control strategies to further improve the multi ejector enhanced parallel compression systems. Compared to HFC404A units, R744 ejector supported units with parallel compression and a pressure lift of around 15 bar do have the highest energy efficiency values and represent the next generation of R744 technology, which can be applied globally, significantly reducing both direct and indirect greenhouse gas emissions.

未来的超市制冷机组需能够适配超市建筑内的全部能源流与能源需求。除为中低温陈列柜提供制冷量外，还应将暖通空调（Heating, Ventilation and Air Conditioning，简称HVAC）机组的热泵需求纳入需求规范范畴。此举可降低总投资与运维成本，同时得益于余热的直接利用以及空调模式下先进的容量控制策略，还能进一步削减总能耗。因此，需对R744商用制冷机组的系统架构进行优化适配，使其能够以尽可能高的能效完成各项既定任务，具体包括在低温、中温及空调温度工况下对蒸发温度与蒸发器出口工况进行精准控制。本文将探讨用于热泵与空调运行的辅助蒸发器集成方案，以及可进一步优化多喷射器强化并联压缩系统的控制策略。与HFC404A机组相比，搭载并联压缩系统、压升约15巴的R744喷射器辅助机组拥有最优的能效表现，属于可全球推广的新一代R744技术，能够显著降低直接与间接温室气体排放。