Types of refrigeration compressors for industrial chillers The energy efficiency ratio of the chiller compressor of the chiller unit determines the energy efficiency ratio of the entire refrigeration system. Since the ambient temperature changes, the compressor is in a partial load state most of the time, so the compressor must have energy regulation.
Types of refrigeration compressors for industrial chillers: 1. Positive displacement refrigeration compressor Positive displacement compressors realize processes such as steam suction, compression, and exhaust steam by changing the volume of the working chamber. Such compressors are reciprocating compressors and rotary compressors. Speed-type compressors work by high-speed rotation, increase the pressure, and complete the task of transporting steam. Such compressors include centrifugal and axial compressors, and centrifugal refrigeration compressors are commonly used. It has a wide range of applications, mature manufacturing technology, simple structure, low requirements for processing materials and processing technology, relatively low cost, strong adaptability, can adapt to a wide pressure range and cooling capacity requirements, and has strong maintainability. Disadvantages: higher speed cannot be achieved, the machine is large and heavy, it is not easy to achieve light weight, the exhaust is discontinuous, the air flow is prone to fluctuations, and there is greater vibration during work. Due to the above-mentioned characteristics of crankshaft connecting rod compressors, few small displacement compressors have adopted this structure. Crankshaft connecting rod compressors are mostly used in large displacement air conditioning systems for passenger cars and trucks.The 2. Screw refrigeration compressor Screw refrigeration compressor is a rotary positive displacement compressor. It uses the change of the cogging volume and position of the screw to complete the process of vapor suction, compression and exhaust. Oil-free screw compressors came out in the 1930s, mainly used to compress air. Later, the oil-injected screw compressor appeared in the cylinder, and its performance was improved. The oil-injected screw compressor has become one of the main types of refrigeration compressors. Screw compressors are divided into two categories: twin screw and single screw. Twin screw compressors are traditionally called screw compressors. This refrigeration compressor is often used in screw chillers 3. Variable displacement refrigeration compressor The variable displacement compressor can automatically adjust the power output according to the set temperature. The air conditioning control system does not collect the temperature signal of the m vent of the evaporator, but controls the compression ratio of the compressor according to the pressure change signal in the air conditioning pipeline to automatically adjust the temperature of the m vent. In the whole process of refrigeration, the compressor is always working, and the adjustment of the refrigeration strength is completely controlled by the pressure regulating valve installed inside the compressor. When the pressure in the high-pressure end of the air conditioning line is too high, the pressure regulating valve shortens the stroke of the piston in the compressor to reduce the compression ratio, which will reduce the cooling intensity. When the pressure at the high-pressure end drops to a certain level and the pressure at the low-pressure end rises to a certain level, the pressure regulating valve increases the piston stroke to increase the cooling intensity. 4. Fixed displacement refrigeration compressor The displacement is increased proportionally with the increase of the engine speed. It cannot automatically change the power output according to the demand for refrigeration, and it has a relatively large impact on the engine's fuel consumption. Its control is generally realized by collecting the temperature signal of the air outlet of the evaporator. When the temperature reaches the set temperature, the compressor stops working; when the temperature rises, the compressor starts working. The fixed displacement compressor is also controlled by the pressure of the air conditioning system. When the pressure in the pipeline is too high, the compressor stops working
