Test Method for Determination of Corrosion and Fouling Tendency of Cooling Water Under Heat Transfer Conditions

10.1520/d4778 ◽  
2008 ◽  
Author(s):  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Chunping Lu ◽  
Jianyu Li ◽  
Dongli Tan

Due to the high speed and high temperature of engine exhaust, the turbocharger bears very high heat load. The heat dissipation of turbocharger is an important factor to determine the service life and performance of turbocharger. In this paper, a mathematical model of the fluid-structure interaction heat transfer of the water-cooled bearing body of turbocharger was established and the cooling performance of a 1.8 L gasoline engine turbocharger was analyzed. The effects of cooling water inlet flow, engine exhaust temperature, cooling water inlet temperature, and wall roughness of cooling water chamber on the cooling performance of important parts of the bearing body were analyzed by the numerical simulation method. In addition, the cooling water flow required by bearing body with a different structure under different working conditions was studied based on the orthogonal test method. The predicted result shows a good agreement with the experiment result, which could provide a reference for relevant production design and cooling strategy. In the range larger than the thickness of laminar flow bottom layer of the cooling water chamber wall, the increase of wall roughness height can enhance the heat transfer between the fluid and the solid.


Author(s):  
Ahmet Selim Dalkilic¸ ◽  
O¨zden Ag˘ra

Determination of condensation heat transfer coefficients for HFC-134a in a 7 mm i.d. vertical smooth copper tube and R600a in a 4 mm i.d. horizontal smooth copper tube are experimentally investigated. The test sections are 1 m long horizontal and 0.5 m long vertical counter flow tube-in-tube heat exchangers with refrigerant flowing in the inner tube and cooling water flowing in the annulus. The experiments are performed at average qualities ranging between 0.1–0.99 for the horizontal test section and 0.67–0.99 for the vertical test section. The mass fluxes are ranging between 50–120 kg m−2s−1 and saturation temperatures are between 30–43 °C for the horizontal test section, the mass fluxes are around 29 kg m−2s−1 and saturation temperatures are between 30–36 °C for the vertical test section. The experimental apparatus are designed to capable of changing the different operating parameters such as mass flow rate and condensation temperature of refrigerant, cooling water temperature, and mass flow rate of cooling water etc and investigate their effect on heat transfer coefficients and pressure drops. The ex-proof diaphragm pump for R600a and the gear pump for R134a are used to circulate the refrigerant in these systems. The detailed description of design and development of the test apparatus, control devices, instrumentation, and the experimental procedure are reported and the study of experimental setups from the available literature survey with the existing ones are compared in this paper. The condensation heat transfer coefficients are obtained for two different test sections with various experimental conditions and compared with some well-known correlations in the literature.


Author(s):  
Yu. P. Morozov

Based on the solution of the problem of non-stationary heat transfer during fluid motion in underground permeable layers, dependence was obtained to determine the operating time of the geothermal circulation system in the regime of constant and falling temperatures. It has been established that for a thickness of the layer H <4 m, the influence of heat influxes at = 0.99 and = 0.5 is practically the same, but for a thickness of the layer H> 5 m, the influence of heat inflows depends significantly on temperature. At a thickness of the permeable formation H> 20 m, the heat transfer at = 0.99 has virtually no effect on the thermal processes in the permeable formation, but at = 0.5 the heat influx, depending on the speed of movement, can be from 50 to 90%. Only at H> 50 m, the effect of heat influx significantly decreases and amounts, depending on the filtration rate, from 50 to 10%. The thermal effect of the rock mass with its thickness of more than 10 m, the distance between the discharge circuit and operation, as well as the speed of the coolant have almost no effect on the determination of the operating time of the GCS in constant temperature mode. During operation of the GCS at a dimensionless coolant temperature = 0.5, the velocity of the coolant is significant. With an increase in the speed of the coolant in two times, the error changes by 1.5 times.


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