Performance analysis and comparison of the four types of comPosition:Home > Blog > Industry News
1. Screw compressor performance analysis
Since the 1970 s, the working reliability of the screw compressor continuously improve, therefore in the medium range of refrigeration and air conditioning refrigerating capacity is more commonly used in engineering, and relies on high reliability and efficiency of successfully into smaller dictated by the original piston compressor refrigeration range (below 750 kw). Screw compressor so successful, let's analyze the performance of it.
(1). The higher the speed of the screw compressor (usually in more than 3000 r/min), and small volume, light quality, covers an area of small advantages, and economical.
(2). The screw compressor without reciprocating inertia force quality, dynamic balance performance is good, so the foundation can be very small.
(3). The screw compressor, simple and compact structure, less wearing parts, so the operation cycle is long, use and reliable, to achieve automatic operation.
(4). The screw compressor with the characteristics of a compulsory gas capacity is hardly affected by stress. Work in a wide range, can still keep high efficiency.
(5). Because there is no air suction valve and exhaust valve, so it is different from the reciprocating compressor, from its structure and type of compressor have stronger than, the compressed structure is quite simple. All compressor is rolling, the support of half seal design, eliminated the design of the seal, and guarantee the gas leak is free running.
(6) of the screw compressor are rotating type compressor, it has no way of the compression of the centrifugal or reciprocating motion. And its compression and exhaust pressure vibration is very low, because the screw rotates, recovery and compression occurs 6 times a week, such as compression process puts in a coin will fall due to vibration.
Within the scope of screw compressor in middle refrigerating capacity also has good thermal performance, and has a good regulation performance, can adapt to the harsh working conditions change. At the same time, in order to guarantee the normal operation of screw refrigeration compressor, and you must configure corresponding auxiliary institutions, such as lubricating system, capacity adjustment control device, safety device and monitoring instrument, etc.
Screw compressor although possesses the advantages of single stage pressure ratio is high, but with the increase of pressure ratio, leakage loss also increased sharply, the working condition of low temperature efficiency significantly reduced during operation.
2. Analysis of piston compressor performance
Piston compressor is the most widely used to date a model, although its market share has been occupy a part of other forms of compressor, but in small refrigerating capacity applications, piston compressor will continue to expand their possession of the market. Below is the piston compressor performance is analyzed.
(1). As a result of clearance volume, suction and exhaust pressure loss, the gas and the heat exchange between the cylinder wall and reveal that the influence of such factors. Compressor's actual capacity value is less than its theoretical capacity.
(2). Because of the piston, piston ring and cylinder wall friction and drive of the lubricating oil pump power loss, make the mechanical efficiency of the compressor is in commonly between 0.75 to 0.9.
(3). The compressor exhaust overheating will reduce the coefficient of gas compressor and power consumption to increase, will cause the excessive expansion of piston and stuck inside the cylinder, and a closed compressor built-in compressor burned, affect the service life of the compressor. For R717 and R22 exhaust temperature should be lower than 150 ?, for R12 should be lower than 130 ?.
(4). As a result of the compressor internal flow resistance, mechanical friction and heat exchange exists, is not the isentropic compression process, but a polytropic process.
3. The analysis of the rolling rotor compressor performance
Rolling rotor compressor is now widely used in electrical appliances in the refrigerator and air conditioner, the large and medium-sized rolling rotor compressor is also used in cold storage. Analysis of its performance.
(1). Less parts, simple structure.
(2). Less vulnerable parts, reliable operation.
(3). No air suction valve slice, clearance volume small, the gas transmission coefficient is higher.
(4). In the case of the same refrigerating capacity, compressor small volume, light weight, running balance.
(5). Machining accuracy is higher.
(6). The sealing line is longer, sealed performance is poor, leakage loss is bigger.
(7) between the vane and the cylinder wall leakage, friction and wear is bigger, limits its service life and efficiency.
4. The performance of the vortex compressor
Scroll compressor is developed in the 1980 s to the compressor, it is with high efficiency, small volume, light quality, low noise, simple structure and balance the characteristics such as widely used in air conditioning and refrigeration unit. The following is to introduce the performance of it.
(1). The pressure difference between two room is small, small amount of gas leak.
(2). Because of the suction, compression, exhaust process is continuous at the same time, pressure rise slowly, so the torque change in small, little vibration.
miniature compressor  refrigeration compressor