目前，根据ANSI/ASHRAE标准15-1994，使用B1或B2组制冷剂的直接膨胀制冷或空调设备禁止在室内使用。双壁换热器的使用也带来了技术和经济挑战。一个成功的项目将是开发B1组和B2组制冷剂新应用的关键一步，并将鼓励暖通空调制造商投资开发在双壁热交换器中使用这些制冷剂的新产品。本研究项目的目标有两个:1）风险分析将评估带有通风环形空间的直接双壁室内蒸发器（或热泵冷凝器）的安全性。关于B2组制冷剂和双组分制冷剂的现有文献和法规- 应对饮用水系统和其他应用的壁式热交换器进行审查。将风险与按照ANSI/ASHRAE标准15-1994建造的机房内安装的设备进行比较。一个目标是确定在直接膨胀通风双壁室内蒸发器中使用B1组或B2组制冷剂的住宅或轻型商用空调系统是否以及在何种条件下可以达到可接受的安全性。2） 双壁热交换器的结构和设计标准。应审查符合任务1下制定的安全要求的双壁制冷剂-空气热交换器的设计选项。应从安全角度制定设计标准，阐明使用B1或B2组制冷剂和双壁热交换器的系统的要求。 文件大小:783KB（801792字节）连接速度估计时间拨号（56K）1分钟，54秒ISDN（128K）0分钟，50秒DSL/电缆（768K）0分钟，8段1（1.5M）0分钟，4秒

At present, direct expansion refrigeration or air conditioning equipment using a Group B1 or B2 refrigerant is prohibited for indoor use under ANSI/ASHRAE-Standard 15-1994. The use of double walled heat exchangers also poses technical and economic challenges. A successful project would be a key step toward opening up new applications for Group B1 and B2 refrigerants, and would encourage HVAC manufacturers to invest in the development of new products using these refrigerants in double walled heat exchangers.The objectives of this research project are twofold: 1) A risk analysis will evaluate the safety of a direct, double-walled indoor evaporator (or condenser in heat pumping) with a vented annular space. The body of existing literature and regulations on Group B2 refrigerants, and on double-walled heat exchangers for potable water systems and other applications, shall be reviewed. The risks are to be compared with those of equipment installed in a machinery room constructed as per ANSI/ASHRAE Standard 15-1994. One goal is to determine whether, and under what conditions, a residential or light commercial air conditioning system with a Group B1 or Group B2 refrigerant in a direct-expansion vented double-walled indoor evaporator could be made acceptably safe. 2) Structure and design criteria for double walled heat exchangers. Design options for a double-walled refrigerant-to-air heat exchanger, consistent with the safety requirements developed under Task 1, shall be reviewed. Design criteria shall be developed from a safety standpoint, spelling out the requirements for a system using a Group B1 or B2 refrigerant in conjunction with a double walled heat exchanger.File Size:783KB (801,792 bytes)Connection SpeedEstimated TimeDial-up (56K)1 min, 54 secISDN (128K)0 min, 50 secDSL/Cable (768K)0 min, 8 secT1 (1.5M)0 min, 4 sec