This company has developed a new plate heat exchanger for heat-pump cooling and heating equipment with a heat-transfer performance that it reportedly triple that of conventional models. Specifically, the new heat exchanger reduces the number of plate layers, allowing the refrigerant charge to be reduced to approximately one-third that of conventional levels, resulting in lower environmental impact and improved safety.
Global regulations are increasingly requiring a shift to next-generation refrigerants and a reduction in the refrigerant charge in heat pump cooling and heating equipment. While next-generation refrigerants like R32 have a lower Global Warming Potential (GWP), many are flammable, making it essential to minimize their volume to reduce the danger of accidental leaks. Although increasing heat transfer performance reduces the refrigerant charge, conventional heat exchangers with grooved plates perform insufficiently. Inserting micro-offset fins between the flat plates was considered to promote heat transfer, but tests confirmed that the refrigerant’s gas-liquid two-phase flow does not distribute uniformly across an entire plate.
Source: Mitsubishi Electric
This new plate heat exchanger has distribution channels at the fluid inlets and outlets that ensure uniform refrigerant flow across plates, even those fitted with micro-offset fins. The result is an even distribution of gas-liquid two-phase flow refrigerant. Channel placement was optimized using proprietary analysis technology that simulates the complex flow of two-phase refrigerants between fine fins. As a result, this new device has achieved industry-leading heat transfer performance, approximately three times that of conventional heat pump-type cooling and heating equipment.
This technology can be applied to a wide range of products, including water-based cooling and heating equipment, heat pump systems for electric vehicles (EVs) and air-cooled air conditioners. The manufacturer plans to incorporate this new technology into its larger product lineup. — Mitsubishi Electric Corp., Tokyo, Japan