With the continuous development of refrigeration technology and the rapid expansion of cold storage capacity, how to keep cold storage with high efficiency and low energy has become a bottleneck restricting the development of cold storage. Aiming at how to configure a suitable heat exchange system, how to improve the refrigeration efficiency of the heat exchange system, and how to reduce the cold loss in the refrigeration process, this paper puts forward reasonable suggestions for the construction of cold storage through technical measures.

1. The influence of heat exchanger on energy consumption of cold storage

3). When the heat exchange surfaces of the air cooled condenser and the cold room air cooler are covered with oil layers, the condensation temperature will increase and the evaporation temperature will decrease, resulting in a decrease in cooling capacity and an increase in power consumption. When there is a 0.1mm thick oil layer on the inner surface of the air cooled condenser, the cooling capacity of the compressor will decrease by 16.6%, and the power consumption will increase by 12.4%. requirements, the evaporation temperature will drop by 2.5 ℃, and the power consumption will increase by 9.7%.

4). The air in the air cooled condenser will increase the condensing temperature. When the air pressure in the system reaches 0.2MPa, the power consumption will increase by 18% and the cooling capacity will decrease by 8%. Air.
5). Regularly remove scale and clean the circulating water pool to keep the condensed water clean. When the scale of the condenser is 1.5mm, the power consumption will increase by 10%.
6). The surface of the cold room air cooler is covered with a layer of frost, which reduces the heat transfer coefficient, especially when the outer surface of the finned tube is frosted, which not only increases the heat transfer resistance, but also makes the air flow between the fins difficult, reducing the appearance of The heat transfer coefficient and heat dissipation area. When the indoor temperature is lower than 0°C and the temperature difference between the two sides of the evaporator tube group is 10°C, the heat transfer coefficient of the evaporator after working for one month is about 70 before frosting.
7). The gas inhaled by the compressor of the cold room condensing unit allows a certain degree of superheat, but if the degree of superheat is too large, the specific volume of the inhaled gas increases, the cooling capacity decreases, and the relative power consumption increases.

Other energy-saving measures for refrigeration operation:
1. The compressor of the cold room condensing unit is one of the core components of the heat exchange system. In the design of the cold storage, the maximum load is often used to select the compressor. According to the load, the number of compressors is reasonably adjusted or the number of working cylinders of the compressor is reduced to make the system load. It matches the cooling capacity of the compressor to prevent the phenomenon of "big horse-drawn carts" and increase energy consumption. In the process of compressor selection and configuration, try to choose the "1+1" matching mode, that is, use a larger compressor with a small compressor or match two compressors with the same load, so that the are operating optimally, not at full load.
2. The evaporative condenser has the characteristics of fast heat exchange speed, complete heat exchange, and no blockage of the spray device. It saves the investment of cooling tower, water pump and circulating water pool, and the cooling water flow is only 1/1 of that of the water-cooled condenser. 10, the energy saving effect is remarkable. Medium and large-scale cold storage should try to choose mainstream evaporative condensers, which can not only make full use of external natural conditions to achieve refrigeration of refrigerants, but also have positive significance for reducing the production cost of enterprises.
3. The heat transfer of the envelope structure and the thermal insulation layer accounts for 20%-35% of the total heat load of the cold storage, so reducing the heat load of the envelope structure can achieve the purpose of energy saving.
4. The opening and closing of the cold storage door will cause a large loss of cooling capacity, and the poor performance of the cold storage door may increase the energy consumption by 15% or more. If the door of the cold storage is not closed in time, a large amount of hot air will enter the cold storage, and the combination of hot and humid air will easily form frost on the surface of the air cooler and the evaporator, and will also break the balance of the temperature field of the cold storage and increase the burden on the refrigeration unit.
5. For the ammonia system, drain oil, air, defrost and remove scale regularly to maintain good heat transfer effect of the equipment and avoid excessive condensation pressure and low evaporation pressure.