Integrated CO2 system for refrigeration, air conditioning and sanitary hot water.

The manufacturers of refrigeration equipment are facing challenges related to the legislative requirements forcing them to implement less conventional refrigerants with lower Global Warming Potential (GWP) in their new products. The newly introduced next generation of hydrofluorocarbons (HFCs) with ultra-low GWPs does have a very short (atmospheric) lifetime, however, the decomposing products are highly toxic in combination with water, and distributed everywhere they do not represent a safe and sustainable alternative. Natural working fluids like CO2 have demonstrated to be an energy efficient and environmentally benign alternative. Since its fluid- and thermosphysical properties are quite different from most other working fluids, the refrigeration system designs have to be carefully adapted to the properties of CO2, thereby maximising the energy efficiency and minimising the total cost of ownership. Integrated CO2 systems can simultaneously provide refrigeration capacities at various temperature levels as low as -50 °C, Air Conditioning (AC), heating and even sanitary hot water at adequate temperature levels. A further integration of advanced thermal storage devices will enable these systems to become a valuable element within smart (thermal) grids.
Examples of the latest system developments applicable in industrial- and commercial refrigeration are shown in the article.

制冷设备制造商正面临立法要求带来的挑战——这些法规迫使他们在新产品中采用全球变暖潜值（GWP）更低的非传统制冷剂。新一代引入的超低GWP氢氟烃（HFCs）虽具有极短的大气寿命，但在与水结合时，其分解产物毒性极强；且由于这类产物无处不在，它们并非安全可持续的替代方案。二氧化碳（CO₂）等天然工质已被证明是高效节能且环境友好的替代选择。由于其流体及热物理性质与大多数其他工质差异显著，制冷系统设计必须根据CO₂的特性进行精心调整，以实现能效最大化与全生命周期成本最小化。集成式CO₂系统可同时提供低至-50°C的多温度级制冷能力、空调（AC）服务、供暖及适宜温度的生活热水。进一步整合先进储热装置后，这类系统将成为智能（热力）电网中的关键组成部分。本文展示了适用于工业及商业制冷领域的最新系统发展案例。