Heat pump drying is a highly efficient energy-saving product. Compared with traditional drying, the energy-saving effect is remarkable, and the drying quality of the dried material is kept better. The unit adopts heat recovery technology and the comprehensive energy efficiency is up to 5.0. Especially suitable for drying sensitive and volatile products, improve the quality of the material. At the same time, the entire heat pump drying process adopts intelligent control technology, and a variety of drying process curves are built in, which saves labor costs, saves time, and saves labor. At present, in the fields of agriculture, food, chemical industry, pottery industry, medicine, mineral processing, pulp and paper, wood processing and textile industries, almost all industries have drying processes. Drying has become a key factor in improving product quality during the production process. Link, but the drying process is also a high-energy process. Among the total energy consumption of various industrial sectors in China, the drying energy consumption is 4% (chemical industry) - 35% (papermaking industry). Developed countries, such as the United States, France, Britain, Japan, etc., have about 12% of industrial energy consumption for drying. Heat pump drying is a gentle, nearly natural drying, suitable for most heat-sensitive materials such as agricultural products and medicinal materials. Therefore, in the field of drying technology, the application of heat pumps can effectively use energy, protect the environment, reduce the greenhouse effect and prevent the destruction of the ozone layer. A heat pump is a system that uses a small amount of high-quality energy (mechanical energy, electrical energy, etc.) or high-temperature heat energy to collect low-quality heat energy in air, and uses a condenser to release heat to provide heat. China’s GDP has been growing at a high rate of over 8% for many years. However, the ensuing energy problems have become more and more serious. With the development of the times and the increasingly tense energy, the efficiency and energy saving of various industries are increasing. The requirements are getting higher and higher. Heat pump is a highly efficient energy-saving technology. It can be used to reduce energy consumption in the drying process and is of great significance for alleviating the energy shortage in China. I. History and problems of vegetable drying in China At present, the dehydration vegetable production mostly adopts the traditional drying method—the heating and drying method of drying the fire in the room. It has the following problems: 1, heating temperature is too high. Traditional technology drying technology, the heating temperature is not easy to control. The general heating temperature is about 75-90°C, and the drying process of dehydrated vegetables requires the drying temperature not to exceed 65°C. 2, drying time is too long. With traditional methods, it takes at least 24 hours per 1 ton of vegetables to be processed, even if this happens occasionally due to poor drying and re-heating and drying. 3, large energy consumption. The traditional drying process has a low thermal efficiency of about 30% to 60%. During the drying process, about 36% of the heat is evaporated by drying, and about 58% of the exhaust gas is lost. The dry material removes heat and dryer heat. The losses accounted for 2% and 2%, respectively, and the thermal efficiency was only 40%. Second, the advantages of heat pump drying technology in the production of dehydrated vegetables Heat pump drying technology has been widely applied to computer rooms, warehouses, archives, libraries, and other industries due to its unique characteristics. Its advantages when applied to the production of dehydrated vegetables are: 1, the heating temperature is low. The heat pump drying technology can be reduced by about 38-52°C compared to the traditional drying process, and the heating temperature of the heat pump drying process is about 37°C. 2, drying time is short. Heat pump drying dehydrated vegetable production process, the maximum time required will not exceed 8h, generally from the preheat to the product 4h can be completed. 3, good quality. The vegetables produced by the heat pump drying process have a good color and a stable internal quality. 4, low energy consumption. Because this process utilizes air circulation, the heating temperature is low, the drying time is short, and the capacity is large. Therefore, the heat pump drying process consumes less energy and is a very good energy-saving product. Third, heat pump drying principle The common heat pump drying device adopts a convection type drying system. The gas from the heat pump heats and dehydrates the raw materials in the drying device. IV. Analysis of Economic and Technical Indexes of Heat Pump Drying and Traditional Drying Processes The test results show that the various economic and technical indicators of the heat pump drying technology process are significantly better than the traditional drying process, mainly reflected in the aspects of energy saving, high quality, and high efficiency. 1, energy consumption comparison 1) Heat pump drying process: According to the test results, the heater (ie, the heat pump main unit) consumes 20 kg of standard coal for 1 t of fresh vegetables, 2.75 kW of heat pump, and 0.2 kW of power for the circulating fan. The energy consumption is 11.8 kW according to 4 h of work. Standard coal The conversion factor is 407g/(kW·h), 4.803kg standard coal. The total energy consumption is 20kg + 4.803kg = 24.803kg (standard coal). 2) Traditional drying process: A total of 240kg of standard coal is consumed, and the power consumption of the circulating fan is 2.4kW, which translates into a standard coal ratio of 407g/(kW·h), equivalent to 0.977kg of standard coal. The total energy consumption is 240+0.977=240.977kg (standard coal). 3) Calculate the energy saving rate: (1-24.803/240.977) × 100% = 90%. 2, quality comparison. Heat pump drying process, product quality is stable, good color, there is no exposed substances such as SO2. 3, drying efficiency comparison. The heat pump drying process product has qualified moisture content, no rework, and shorter drying time. V. Comprehensive evaluation The investment of heat pump drying equipment not only saves a lot of energy, but also greatly improves work efficiency. The heat pump drying process is used for vegetable dehydration production. It is a technologically feasible and economically reasonable energy-saving project. This new technology and new process is very successful from theory to practice. Jiangyin Thousands Chemicals Co. , https://www.jywqhxcomposite.com