Optimisation of Process Parameters for Water-Sea Water (3%) system in a Spiral Plate Heat Exchanger (SHE) using Response Surface Methodology (RSM)

In this paper, an attempt is made to optimize the process parameters for Water-Sea Water (3%) system in a Spiral plate Heat Exchanger (SHE). Experiments have been conducted by varying the mass flow rates of cold fluid (Sea Water 3%) and hot fluid (Water) and the inlet temperature of hot fluid by keeping the cold fluid temperature constant. The effects of variables on the process parameters of SHE are studied. The process parameters viz. cold water inlet flow rate (ṁc), hot water inlet flow rate (ṁh) and hot water inlet temperature ( ) are optimized using Response Surface Methodology (RSM) by solving the regression model equation with Design Expert software and also by analyzing the three-dimensional surface plot in order to maximize the overall heat transfer coefficient (U) and to minimize the pumping power (Wp) in SHE. The most influential factor on each experimental design response is identified from the analysis of variance (ANOVA). The optimum conditions for SHE proposed by RSM are as follows : i) ṁc - 0.3182 kg/s , ṁh - 0.8470 kg/s and  - 60°C. At these optimized conditions, the optimum values of U and Wp are found to be as follows: U = 1286.985 W/m2 K and Wp = 0.0525 W. A coefficient of determination (R2) value of 0.9892 for water-sea water (3%) show the fitness of RSM in this work. The optimized values are also verified with experimentation and the results show that the RSM with Box-Behnken design is useful for optimizing the SHE process.