Study on the cooling effect between air compressors Zheng Guiqiu Sun Daixiang through the thermal calculation and test of the 2ZF 0.34/ 3B air compressor interstage cooler, found the factors affecting the cooling effect, and proposed to replace the three heat pipes with two heat pipes. Improved design. It has been verified by experiments that the interstage cooling effect is significantly improved and the cost is saved.
Compressor heat exchanger thermal analysis 2ZF 0.34/3 B air compressor produced by Jiangwei Hengwei Marine Auxiliary Machinery Manufacturing Co., Ltd. is a medium-pressure reciprocating piston air compressor. The II exhaust temperature is always close. 200 ° C. This product has been widely used for the starting and braking of emergency start, supplemental gas source, small and medium-sized diesel engines and hydropower equipment for large ships. As the field of application continues to expand, the product is used as a continuous full load operation, and users have put forward new requirements for Class II exhaust temperatures. Additional Class II aftercoolers are not allowed due to factors such as price and product cost. Therefore, improving the cooling effect of the interstage cooler has become one of our research topics.
1 Principle structure analysis According to the thermal calculation of the air compressor, the compression final temperature type of the air compressor: T --- the inhalation temperature of each level -- the pressure ratio of the cylinders at each level --- i multi-party compression index.
From the above analysis, the main reasons affecting the temperature of the Class II exhaust gas are: 1 ambient or Class I intake air temperature, which is difficult to control and regulate.
2 The pressure ratio and multi-compression index of all levels, because it is a stereotyped product, has been selected by the majority of users for a long time. In order to facilitate the maintenance and interchangeability of spare parts, the overall structure cannot be changed greatly.
Author: Zheng Guiqiu is the chief engineer of Jiangwei Hengwei Marine Auxiliary Machinery Manufacturing Co., Ltd., Jiangsu Province. Engineer Sun Daixiang is the deputy director and assistant engineer of the research institute of Jiangwei Hengwei Marine Auxiliary Machinery Manufacturing Co., Ltd., Jiangsu Province.
The 3II inlet air temperature can be achieved by increasing the cooling effect of the interstage cooler.
Obviously, enhancing the cooling effect of the interstage cooler is the first and only best option for the product to reduce the temperature of the Class II exhaust. The cooling effect of the interstage cooler is mainly related to the following factors: 1 fan air volume, wind speed and turbulence degree 2 heat exchange area 3 heat exchange heat resistance.
Our company originally used three U-shaped finned fins as the interstage cooler. Due to structural reasons, it is difficult to increase the heat dissipation area. We reviewed and analyzed the pattern and found that the product has the following problems in interstage cooling: 1 The top half of the heat pipe with three sides arranged side by side has nearly half of the radial direction covered by the pulley rim of the fan. Can be forced by the fan to effectively convective cooling, only for natural wind cooling.
2 Because it is a U-shaped heat pipe group, the cooling air formed by the fan passes through the U-shaped intermediate portion and cannot be cooled to the heat pipe, and only cools the two-stage cylinder, which accounts for about one-sixth of the total area.
3 The heat pipe that is not cooled by the fan should also be thermally calculated according to natural air cooling.
2 Improved design Through structural analysis, we have improved the design of the interstage cooler. That is, two U-shaped heat pipes arranged side by side are selected, and the bending radius of the two inner heat pipes is appropriately increased to the maximum range of the fan containment. At the same time, before the copper tube is unwound, the necking process is increased to increase the turbulence of the hot air. In the thermal calculation, the fan air volume of the U-shaped intermediate area is removed and calculated, and the Jiangsu ship calculation process.
When the Class II intake air temperature is calculated, the fan air volume has been removed from the U-shaped intermediate area.
It can be seen from the above verification calculation that when the three tubes are not considered, part of the hot air is mixed to increase the temperature of the second stage intake air, and other heat cooling is not considered, the two heat pipes are three heat dissipation. The tube-stage interstage cooler has received significant cooling effects.
3 Test Verification According to the improved design, we made two U-shaped heat pipes and conducted comparative verification tests on the same air compressor. The test results show that the use of two heat pipes is lower than the temperature of the second stage of the three heat pipes by 12 to 18 °C.
Through this improved design, each air compressor saves Υ19×1.5 copper tubes of about 1 100mm and tube-length copper fins with a length of about 800mm. At present, the model has been put into mass production and has achieved obvious economic effects.
The calculation result of the project unit is three when the two are in the tube, the airflow speed, the airflow in the tube, the Reynolds number, the gas heat transfer coefficient, the fan air volume, the outer cooling airflow speed, the cooling airflow, the Reynolds number, the outer airflow heat transfer coefficient, the unit length, the light pipe, the outer surface area, the unit length, the fin surface area. The total heat exchange area per unit length of the unit is the logarithmic average area per unit length. The total heat transfer coefficient of the internal surface area is II. The intake air temperature is more. The stronger the creative capacity of the enterprise, the more energetic the enterprise will be. The world's leading companies are known for their emphasis on research and development.
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The center is the central link of the corporate group, whose main responsibility is to raise, use and sell resources. The profit center has operational autonomy, independent economic status and legal status. 3 Cost center, the factory or production unit of each company within the enterprise group is the cost center. The responsibility of the cost center is to complete the specified tasks at a certain cost. The three institutions are: 1 decision-making body, which refers to the board of directors of the enterprise group. The decision-making power exercised by the board of directors is generally only a strategic decision and cannot involve the general production and operation of the general manager. 2 The executive agency, general manager and other senior staff and functional departments are the highest executive leaders of the enterprise group, presiding over the daily work of the enterprise. 3 Supervisory organization, refers to the board of supervisors, whose function is to supervise all business management activities of the group. The board of supervisors independently exercised the power of supervision.
In short, enterprise groups only have a clear development strategy, with first-class talents, and the ability to continuously innovate, in order to achieve sustainable development, enduring. ? Ship power plant?
Study on the Cooling Effect of Zheng Guiqiu Sun Daixiang Air Compressor
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