High-temperature heat pump based on Mechanical Vapor Recompression technology for 150°C steam supply in an industrial drying process
This paper presents the development and application of an innovative high-temperature heat pump system, which was specifically engineered to address the needs of a leading provider of industrial insulation solutions. The system was installed at a major production facility in Roslev, Denmark and integrated in a drying process, replacing steam from a traditional gas-fired boiler. The implemented heat pump uses mechanical vapor recompression (MVR) technology, enabling the recovery and upgrading of low-grade thermal energy. The cycle features six centrifugal blowers, that compress up to 4 tons of process vapors from 1 bar(a) to 4.8 bar(a) and deliver up to 4.5 tons of steam per hour close to saturated temperature. The thermal output of the system reaches 2.65 MWth, requiring a power input of only 0.48 MWel, resulting in a coefficient of performance (COP) of 5.5. A notable feature of this open system is that a dew-point-optimized process allowed the direct use of the exhaust water vapors as working fluid, which eliminates potential environmental hazards and enhances overall system efficiency and sustainability. The excellent thermodynamic properties of water, combined with the multi-stage design, contribute to high efficiency in heat recovery, significantly reducing electricity consumption. In addition to the core heat pump functionality, the system integrates advanced modules to support process optimization. These modules include a de-superheating control unit to regulate steam temperature between stages and an operating point monitoring (OPM) system that ensures efficient performance under variable process conditions. In drying applications where high temperature and high efficiency are essential, High-temperature heat pumps based on Mechanical Vapor Recompression technology present a promising alternative. As a result of this implementation, the Branden plant in Roslev estimates to reduce its CO2 footprint by 42%, saving 6,800 tons of CO2 annually.