Brazed plate heat exchangers (BPHE) rely on a filler metal to permanently bond stainless-steel plates together under vacuum or controlled atmosphere. The most widely used filler materials are copper (Cu) and nickel-based stainless-steel brazing alloys. Though they share the same structural principle, the choice of brazing material determines the exchanger’s temperature resistance, corrosion behavior, and application suitability.
钎焊板式换热器通过钎料在真空或保护气氛下将不锈钢板永久连接。最常用的钎料为铜基钎料与镍基不锈钢钎焊材料。虽然结构原理相同，但钎料的不同决定了换热器的耐温性能、耐蚀性及应用范围。
Aspect 项目 | Copper Brazing 铜钎焊 | Stainless-Steel (Nickel) Brazing 不锈钢（镍基）钎焊 |
Typical filler 钎料 | Pure copper or Cu-based alloy | Nickel-based or iron-nickel alloy |
Brazing temperature 钎焊温度 | ~1080 °C | 1100–1200 °C |
Base material 母材 | AISI 304/316L | AISI 316L, duplex, or high-alloy steels |
Corrosion resistance 耐腐蚀性 | Good for neutral/non-aggressive media | Excellent for corrosive or chloride-rich fluids |
Mechanical strength 机械强度 | Moderate; limited above 200 °C | Higher; stable up to 600 °C |
Thermal conductivity 导热性 | Very high (Cu = 390 W/m·K) | Lower (Ni ≈ 90 W/m·K) but uniform at high temperature |
Cost 成本 | Economical | Higher due to nickel alloy and vacuum brazing complexity |
**Copper-Brazed BPHE 铜钎焊型**
· • Excellent thermal efficiency due to high copper conductivity.
· • Ideal for HVAC, refrigeration, and water-based heating systems.
· • Compact and cost-effective for medium pressure applications (≤ 45 bar).
· • Sensitive to ammonia, sulphur compounds, and chlorides.
**Stainless-Steel/Nickel-Brazed BPHE 不锈钢（镍）钎焊型**
· • Superior chemical resistance against ammonia, seawater, glycols, organic acids, and CO₂.
· • Suitable for high-temperature and high-pressure processes (up to 600 °C, 100 bar).
· • Longer service life in industrial, marine, and food-grade environments.
· • Slightly lower heat-transfer rate but compensated by reliability and durability.
Copper-Brazed Units 铜钎焊型 | Nickel-Brazed Units 镍钎焊型 |
Heat pumps & chillers | Ammonia evaporators & condensers |
Domestic water heating | Seawater coolers & brine systems |
Oil coolers & compressor intercoolers | Chemical & food process equipment |
Refrigeration systems (R410A, R134a) | HFO refrigeration systems |
· • Copper brazing continues to dominate HVAC and standard industrial markets due to low cost and proven reliability.
· • Stainless-steel (nickel) brazing is expanding in ammonia, marine, hydrogen due to corrosion resistance and sustainability.
· • Hybrid and diffusion-bonding technologies are emerging for extreme environments.
· • Future trends include AI-based design, laser-brazing precision, and recyclable materials for sustainable manufacturing.
Both copper and stainless-steel brazing technologies have distinct strengths. Copper brazing offers unmatched efficiency and cost-effectiveness for standard HVAC applications, while nickel/stainless-steel brazing provides reliability under extreme conditions. The global trend points toward diversification — applying each technology in its most suitable environment for performance and sustainability.
铜钎焊与不锈钢钎焊各具优势。铜钎焊以高效与经济性在常规暖通领域占主导，而镍钎焊凭借高耐蚀与高温性能在工业与新能源领域快速扩展。未来发展将更加多元化，使每种技术在最适宜的环境中发挥最大效能与可持续价值。
No.
Copper reacts with ammonia and may suffer stress corrosion or chemical degradation over time. For ammonia systems, nickel-brazed heat exchangers are strongly recommended due to superior chemical compatibility.
Yes, especially at high temperatures.
Nickel-based brazing alloys maintain mechanical stability at elevated temperatures (up to 600 °C), whereas copper-brazed units are generally limited to lower temperature ranges.
However, for standard HVAC conditions, copper-brazed units provide sufficient strength.
Copper has higher thermal conductivity (≈390 W/m·K) compared to nickel alloys (≈90 W/m·K).
This allows copper-brazed BPHEs to achieve excellent thermal efficiency in water-based and refrigeration applications.
However, overall heat transfer also depends on plate design and flow characteristics — not only filler material.
Nickel-brazed heat exchangers are preferred.
Seawater contains chlorides that can accelerate corrosion in copper-brazed units. Nickel-based brazing provides improved resistance in marine environments.
Yes.
Nickel alloy filler materials and higher brazing temperatures increase manufacturing cost. However, in corrosive or high-pressure applications, the longer service life often justifies the investment.
Copper-brazed BPHE: typically up to 45 bar (depending on design)
Nickel-brazed BPHE: can reach 30 bar or higher in specialized industrial designs
Pressure capability depends on plate thickness and construction, not only the brazing material.
Service life depends on operating conditions.
In clean water or HVAC systems → copper brazing offers long and economical service life.
In corrosive, ammonia, or marine environments → nickel brazing typically lasts significantly longer.
Proper material selection is more important than choosing the “stronger” option.
Not exactly.
Nickel-brazed BPHEs use stainless-steel plates bonded by a nickel-based alloy.
Fully diffusion-bonded or fusion-bonded exchangers are different technologies.
