Freezing is one of the most frequent issues in refrigeration systems using BPHEs, especially in evaporators. It occurs when the local temperature of the refrigerant drops below the freezing point of the secondary fluid (usually water or glycol mixture). Ice formation inside the channels blocks the flow, reduces heat transfer efficiency, and can cause permanent deformation or cracking of the plates.
冰冻是钎焊板式换热器在制冷系统（尤其是蒸发器）中最常见的问题之一。当制冷剂的局部温度低于二次介质（通常为水或乙二醇溶液）的冰点时，会在通道内部形成冰层。这种结冰会阻塞流道、降低换热效率，并可能导致板片永久变形甚至破裂。
Prevention / 预防措施：
- 保持足够的流量，避免局部滞流；
- 设置低温保护和流量联锁；
- 在低温应用中使用乙二醇或丙二醇溶液代替纯水。
Corrosion can occur when incompatible fluids or contaminants are present, especially in systems with high chloride content or poor water treatment. For BPHEs with copper brazing, ammonia-based or acidic fluids can also cause severe corrosion. Over time, this leads to pinhole leaks or cross-contamination between circuits.
当工作介质中含有不兼容化学成分或杂质时，腐蚀是另一常见问题。若水质含氯量高或水处理不良，会导致点蚀或晶间腐蚀。对于采用铜钎焊的换热器，氨类或酸性介质也会造成严重腐蚀，最终导致针孔泄漏或两侧介质交叉污染。
Prevention / 预防措施：
- 定期检测水质并保持适当的pH值；
- 高腐蚀性场合选用316L或钛材/镍钎焊换热器；
- 避免含氨或酸性流体与铜钎焊产品接触。
Deposits of scale, oil, or dirt on the heat transfer surface increase thermal resistance and reduce efficiency. In refrigeration systems, this is often caused by oil return issues or poor water filtration.
换热面上附着的水垢、油污或颗粒杂质会增加热阻，降低传热效率。在制冷系统中，这类问题常由回油不良或冷却水过滤不充分引起。
Prevention / 预防措施：
- 保持系统清洁并使用过滤器；
- 采用定期化学清洗（CIP）；
- 控制冷却水硬度和油分离器性能。
Repeated pressure and temperature fluctuations (cycling start/stop) can cause thermal fatigue, resulting in micro-cracks in brazed joints or plate edges.
当系统频繁启停或压力、温度波动较大时，钎焊接缝及板片边缘会因热疲劳产生微裂纹。
Prevention / 预防措施：
- 减少系统启停频率；
- 设置缓启阀和温度控制；
- 在高压差工况下采用多机并联分流设计。
During long-term operation, compressor oil, welding slag, or debris can accumulate inside the channels, reducing flow area and performance.
在长期运行过程中，压缩机油、焊渣或杂质可能积聚在流道内，造成流通截面缩小，换热效率下降。
Prevention / 预防措施：
- 安装油分离器及高效过滤器；
- 定期维护并冲洗系统；
- 在系统初次启动前彻底清洁管路。
Brazed Plate Heat Exchangers are efficient and compact, but their long-term reliability in refrigeration systems depends on preventing freezing, corrosion, fouling, and mechanical fatigue. Proper design and maintenance significantly extend BPHE service life.
钎焊板式换热器具有高效、紧凑、免维护等优点，但其在制冷系统中的长期可靠性取决于防冰冻、防腐蚀、控制水质与油污、减少热应力与压力冲击。通过合理的设计与维护，可显著延长BPHE的使用寿命并确保系统稳定运行。
