STUDY ON DESIGN AND PERFORMANCE OF LOW TEMPERATURE HEAT PUMP EVAPORATION SYSTEM FOR CORROSIVE AND THERMAL-SENSITIVE RAW MATERIAL

摘要

To relieve problems of high-energy consumption and poor corrosion-resistant during the conventional corrosive and thermal-sensitive material evaporation-concentration process, a closed low temperature heat pump evaporation-concentration scheme has been recommended. Through compared with the usual mechanical vapor recompression (MVR) heat pump evaporation-concentration process, a vitamin E solution evaporation-concentration scheme was analyzed as an example, key equipments size, cost, integrated thermodynamic performance and economic performance of the proposed system scheme have been explored. The results showed, compared with the MVR scheme, the closed low temperature heat pump evaporation-concentration scheme hold advantages in comprehensive performance. And raw material evaporation temperature selection affected integrated performance of the proposed scheme less. The comprehensive performance index is decreased with evaporation temperature for both of the two schemes. At the same evaporation temperature increase, the comprehensive performance is decreased less than that of the MVR scheme. Advantage of the proposed scheme became obvious when the evaporation temperature lower than 44 °C. Furthermore, thermodynamic performance of the proposed suggested worse than that of the MVR heat pump, while the key equipment- compressor of the proposed scheme was compact, cost less, and regardless considering the processed corrosive material causticity impaction.