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暖通书馆 编辑 目前，中型空调系统正积极应对低GWP值制冷剂的挑战，未来，我们可能看到更大型冷水机组的使用。 对于冷水机组来说，目前虽然存在很多低GWP值制冷剂替代技术的选择，而小型独立空调系统和中型空调系统已经开展了低GWP值替代制冷剂的行动，但对于合适替代品的选择仍面临诸多挑战。 在4月20-21日泰国曼谷召开的制冷剂替代工作小组会议期间，技术专家和行业代表深入讨论了HFC及其他替代制冷剂。随着全球正在采取低GWP值制冷剂的替代行动，冷水机组的替代将成为关键。另一种可能是，中小型系统使用微可燃制冷剂。但是，与会者不可能提出一条明确的路线。还有一个令人头痛的问题是炎热气候地区，在那里，空调是必不可少的，而且多数是中型系统。当然，目前很多案例指出，对于适用于所有产品的低GWP方案原则上可以用于高温环境条件。 目前乃至近期，冷水机组被看作拥有良好的低GWP值替代制冷剂的一个子行业。这些替代品包括碳氢、HFOs、氨和水。 对于小型迷你分体系统，碳氢和HFC32已经作为替代品成功应用。由于在相关标准中对充灌量的限制，碳氢系统的最大容积也被限定了。一位参会者提出，冷量低于3.5 kW的设备可以使用R290。对于大一些的系统如单元机和多联空调器，目前没有合适的非HFC替代品。对于安全级别A2L的微可燃制冷剂，如HFC-32，可以达到最大60 kg的充灌量，这就能够适用于大型产品市场。 制冷、空调和热泵市场是HFCs的主要用户，以GWP值加权的CO2当量吨来计算，该市场在HFC使用总量中的占比达到86%。其中，空调的GWP值加权HFC消费量占比是56%，制冷的占比是30%。 空气源空调系统、商用制冷系统和汽车空调系统是HFCs的主要用户，他们的使用量市场占比分别达到25%，22%和20%。冷水机组和工业制冷系统占比分别是8%和6%。 Are chillers the answer in a low GWP world? THAILAND: With medium-sized air conditioning systems remaining a challenge for low GWP alternatives, the future might see a much broader use of chillers. While there are a number of alternative low GWP refrigerant technologies available for chillers, and there is movement towards lower GWP alternatives for small self-contained air conditioning systems, medium-size air conditioning systems, however, are subject to challenges in the identification of suitable substitutes. This was one of the conclusions of in-depth discussions between technical experts and industry representatives from around the world at a two-day workshop on HFCs and their alternatives, which preceded this week’s Montreal Protocol meeting in Bangkok. As the world moves towards the adoption of lower GWP refrigerants, one possible contribution to solve the problem, it was suggested, would be to change systems towards a broader use of chillers. Another might be the use of mildly flammable refrigerants for smaller to medium-size systems. However, a clear path forward could not be provided by the attendees. The problem was seen to be particularly pronounced for high-ambient climates, where air conditioning is essential and medium capacity systems are particularly prevalent. However many examples were provided where lower GWP options for all uses can be adapted in principle to the highest ambient conditions. Chillers were seen as a sub-sector with good low GWP alternatives available now or in the near future. These alternatives include hydrocarbons, HFOs, ammonia and water. For smaller capacity mini split systems hydrocarbons and HFC32 are already available as alternatives. Due to charge size restrictions in the relevant standards, the maximum capacity of hydrocarbon systems was recognised as being limited. One participant advised that up to 3.5kW capacity, R290 (propane) could be used. For larger systems such as unitary equipment and multi-split air conditioners, no non-HFC alternatives were named. Refrigerants with the “mildly flammable” safety classification A2L, such as R32, can be used up to a charge size of around 60kg; this would cover a large segment of the market. The refrigeration, air conditioning and heat pumps market is the predominant user of HFCs, accounting for 86% of HFC use in terms of GWP-weighted tonnes CO2 equivalent. It is estimated that 56% of the global GWP-weighted HFC consumption is for air-conditioning and 30% is for refrigeration. Air-to-air air-conditioning systems, commercial refrigeration systems and mobile air-conditioning systems dominate the use of HFCs, representing 25%, 22% and 20% of global warming weighted HFC use, respectively. Chillers and industrial refrigeration systems account for another 8% and 6% of global-warming-weighted HFC use, respectively. 转载须注明“转自《暖通空调》杂志官方微信” ================ |
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