Mitsubishi Electric develops plate heat exchanger to cut refrigerant charge by two-thirds
Japan – Mitsubishi Electric has developed a plate heat exchanger for cooling and heating equipment that it says delivers around three times the heat-transfer performance of its conventional grooved-plate design while reducing refrigerant charge to approximately one-third.
Improved refrigerant distribution
Mitsubishi Electric said reducing refrigerant charge is becoming increasingly important as the industry moves towards lower-GWP refrigerants, many of which are flammable.
The company investigated using micro-offset fins between flat plates to improve heat transfer, but found that gas-liquid two-phase refrigerant flow was not distributed uniformly across the plate.
Its new design uses distribution channels at the fluid inlets and outlets to improve refrigerant distribution across plates fitted with micro-offset fins.
The channel positions were optimised using Mitsubishi Electric analysis technology that simulates two-phase refrigerant flow.
Fewer plates required
Mitsubishi Electric says the design achieves around three times the heat-transfer performance of its conventional grooved-plate heat exchangers.
The higher performance allows fewer plate layers to be used, reducing refrigerant charge to approximately one-third of conventional levels.
The company says the technology could be applied to water-based cooling and heating equipment, heat-pump systems for electric vehicles and air-cooled air conditioners.
