Vahterus has introduced Combined+, an evaporator solution that integrates flooded evaporation, droplet separation and suction gas superheating within a single shell. The design reduces installation footprint and piping requirements while retaining the efficiency benefits of flooded evaporation. The solution is intended for industrial refrigeration and heat pump systems using natural refrigerants, including ammonia (NH3), carbon dioxide (CO2) and hydrocarbons.
Combined+ incorporates two dedicated heat transfer sections. The primary section evaporates liquid refrigerant, with the liquid level maintained above the main heat transfer area to support efficient and stable operation. The secondary section acts as a superheater, raising the temperature of saturated suction gas before it enters the compressor. This arrangement helps maintain dry suction gas during start-ups, variable load operation and conditions where condensation may occur in the suction line.
In heat pump applications, the integrated superheater can use an external heat source or high-pressure condensate, which is subcooled during the process. According to Vahterus, using hot condensate as the heat source typically results in COP-neutral operation. The company recommends including a condensate bypass option to provide additional operating flexibility.
Combined+ is available for Vahterus Combined evaporator models 5/3, 6/4, 7/5, 8/6, 9/7 and 14/9. Larger shell sizes can also be used in selected applications to increase superheating capacity and meet specific system requirements.
Shell pressure and temperature ratings remain consistent with standard Vahterus Combined designs. The integrated superheater is available with design pressures of 16, 25, 40 or 60 barg (approximately 232, 363, 580 or 870 psig), with higher ratings available on request. Its pressure rating can be specified independently of the shell and plate pack design pressure, allowing flexibility in system configuration.
