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Two Phase Flow Phase Change and Numerical Modeling Part 4

Tham khảo tài liệu 'two phase flow phase change and numerical modeling part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 80 Two Phase Flow Phase Change and Numerical Modeling calculations of heat transfer coefficient for both shell- and refrigerant-side stream. If the condenser s refrigerant inlet temperature and pressure water inlet temperature hot water and refrigerant mass flow rates and tube size are specified then the condenser s water outlet temperature refrigerant outlet temperature and heat transfer rate can be estimated. The estimation process for rating a condenser Input design parameters The input design parameters include refrigerant inlet outlet temperatures refrigerant inlet pressure water inlet temperature mass flow rate of hot water refrigerant and geometric conditions. Give a refrigerant outlet temperature as an initial guess for computing the hot water outlet temperature Two Twi Qw . rw .c w pw Give an outlet temperature Tr as an initial guess for Section-I. Calculate the properties for Section-I and Section-II. Calculate the overall heat transfer rates by present model. Check the percent error between model predicting and experimental data for overall heat transfer rates. If the percent error is less than the value of 0.01 then output the refrigerant outlet temperature water outlet temperature and heat transfer rate if it is larger than the percent error then reset a new refrigerant outlet temperature and return to the second step. In accordance with the above calculation process the experimental data of Case 1 can be used as input into the present model for rating calculations. The calculation results give the water outlet temperature is 74.84 C refrigerant outlet temperature is 64.35 C and heat transfer rate was is 33.01 kW. Experimental data of Case 2 were used as input into the rating calculation process and another set of result tell water outlet water temperature is 45.16 C refrigerant outlet temperature is 39.04 C and heat transfer rate is 35.03 kW. Repeat the same procedures for the remaining 26 sets of experimental data the calculation results for rating .