Small size, high heat transfer—How does the refrigerant heat exchange plate brazing type achieve a win-win situation in space and performance?
Publish Time: 2025-08-21
In large commercial air conditioners, household multi-split units (VRFs) with a capacity of 5P or more, and air-source heat pump systems, the spatial layout and heat transfer efficiency of the outdoor unit remain a core design challenge. While traditional shell-and-tube or fin-type heat exchangers are technologically mature, they are bulky, heavy, and have limited heat transfer efficiency, making them unable to meet the demands of modern equipment for compactness and efficiency. With its outstanding advantages of "small size and high heat transfer," the refrigerant heat exchange plate brazing type is becoming the preferred solution for high-power refrigeration and heat pump systems, achieving a perfect balance between space utilization and performance.
1. Compact Structure: Microchannels Unleash Huge Heat Transfer Potential
The refrigerant heat exchange plate brazing type is constructed from multiple stacked corrugated stainless steel plates, permanently sealed between the plates through a high-temperature vacuum brazing process, forming alternating channels for hot and cold fluids. This design allows for high-speed fluid flow within the extremely narrow microchannels, generating intense turbulence and significantly improving the heat transfer coefficient. Compared to traditional shell-and-tube heat exchangers, BPHEs can achieve a heat transfer area density 3 to 5 times higher. For example, with the same heat transfer capacity, a brazed plate heat exchanger suitable for a 10P heat pump has a volume only one-third that of a shell-and-tube heat exchanger and weighs over 50% less. This is crucial for space-constrained outdoor unit layouts. It not only frees up more space for optimizing key components like the fan and compressor, but also facilitates overall lightweighting and modular design.
2. Efficient Heat Transfer: A Two-Pronged Approach of Turbulent Flow Design and Material Advantages
The BPHE's high efficiency stems from its unique corrugated plate structure. The common herringbone or cross-corrugated design forces the refrigerant and water (or air-side medium) to continuously change direction during flow, disrupting the boundary layer and significantly enhancing heat transfer efficiency. Furthermore, stainless steel offers excellent thermal conductivity and a smooth surface that resists scaling, ensuring high efficiency over long-term operation. In heat pump systems, especially under low-temperature heating conditions, BPHEs can more effectively extract ambient heat, improving COP. Experimental data shows that at -15°C, heat pump systems using brazed plate heat exchangers (BPHEs) achieve 15%-20% higher heating efficiency than traditional fin heat exchangers, resulting in significant energy savings.
3. Fully Sealed Structure: Zero Leakage, High Pressure Resistance, and Adaptability to Complex Operating Conditions
Air conditioning and heat pump systems operating at 5P and above have high operating pressures, placing extremely stringent sealing requirements. BPHEs are brazed in a vacuum furnace using copper or nickel-based alloys. All joints are metallurgically bonded, completely eliminating potential leak points such as flanges and gaskets, achieving true "zero leakage." Furthermore, BPHEs can withstand operating pressures of up to 30-40 bar, far exceeding the requirements of conventional refrigeration systems, ensuring long-term stable operation under high-pressure, high-temperature, or frequent start-stop conditions. Their excellent seismic resistance makes them suitable for outdoor vibration environments, making them an ideal choice for heat pump outdoor units.
4. Strong Adaptability: Refrigerant Compatibility and System Integration Advantages
Modern BPHEs are compatible with a variety of mainstream refrigerants. Through optimized flow channel design and material selection, they can meet the flow characteristics and thermodynamic requirements of different refrigerants. Furthermore, the refrigerant heat exchange plate brazing type easily integrates with components such as electronic expansion valves, liquid receivers, and oil separators to form a compact refrigeration module. This simplifies system piping, reduces weld points, and improves overall reliability. In variable-frequency heat pump systems, its rapid response also facilitates precise refrigerant flow regulation and temperature control.
5. Easy Maintenance and Long Life
Despite its compact design, the refrigerant heat exchange plate brazing type requires virtually no routine maintenance. Its corrosion-resistant stainless steel construction makes it particularly suitable for areas with complex water conditions. With proper installation and system cleanliness, its service life can exceed 10 years, far exceeding that of traditional heat exchangers.
The refrigerant heat exchange plate brazing type utilizes an innovative microchannel structure, efficient turbulent heat transfer, and a reliable vacuum brazing process to successfully address the conflict between limited space and high performance requirements in high-power air conditioning and heat pump systems. It not only improves the energy efficiency and reliability of the equipment but also promotes the development of smaller, smarter, and more environmentally friendly systems.
