Dry evaporator (single unit)characteristic:
The refrigerant completely evaporates and overheats inside the pipe to become superheated gas, which is beneficial for using a thermal expansion valve to automatically adjust the liquid supply. The commonly used refrigerants include R22, R134a, R407C, R410A, etc. Because the refrigerant evaporates inside the tube, as long as the flow velocity inside the tube exceeds 4 m/s, the lubricating oil inside the tube can be brought back to the compressor, making oil return convenient. In the design, the shell side adopts the E-type structure (baffle type) specified by GB151 or TEMA, and the gap size of the baffle is opened by 15%~50% according to the physical properties and flow rate of the refrigerant. Generally, the flow velocity of the baffle gap is roughly equal to the flow velocity of the refrigerant passing through the tube bundle horizontally. In order to ensure the heat transfer effect, the gap between the baffle plate and the cylinder, and the gap between the heat exchange tube and the baffle plate should be less than or equal to the minimum gap specified by GB151 or TEMA, especially at low temperatures, these gaps are particularly important. Due to the fact that the refrigerant is generally a high viscosity fluid with slow flow velocity and relatively increased thermal resistance at low temperatures, the gap leakage is more obvious. Therefore, in... The control of gaps must be stricter under low temperature conditions.
The heat exchange tube adopts an internally reinforced high-efficiency heat exchange tube, which adopts a spiral groove type inside the heat exchange tube. Generally, there are 32-75 grooves inside the tube, mainly used to enhance the heat transfer effect inside the tube. Sometimes, the outside of the heat exchange tube is also reinforced accordingly. The heat exchange tube can be made of materials such as purple copper T2, high phosphorus purple copper TP2, nickel copper BFe10-1-1, tin copper HSn70-1, aluminum copper HA177-2 according to the different refrigerants. Heat exchange tubes and tube sheets are generally connected by expansion joints. A set of distributors is usually installed at the refrigerant inlet to evenly distribute gas-liquid mixtures. Dry evaporators are generally suitable for use in compressor refrigeration systems with a displacement of less than 2000 m3/h. In large systems, due to uneven refrigerant distribution, this type of evaporator should not be used.

Dry evaporatorSketch Map

Dry evaporatorSpecification and description