Entropy generation minimization optimization design for starting heating temperature of heavy oil in pipeline

Based on the theory of minimizing entropy generation rate, the entropy generation caused by heat loss and frictional resistance of heavy oil in pipeline is analyzed. The initial heating temperature of pipeline is optimized when entropy generation rate is minimum. The result indicates that the minimum entropy generation rate is connected with the mass flow rate, initial temperature and pipeline diameter. The relationship between the flowrate and entropy generation rate is that the higher the flowrate is, the lower the entropy production rate is when the crude oil per unit mass is transported. However, with the increase of transport capacity, the reduce rate of entropy production rate is decreased. Only the appropriate initial heating temperature can ensure the minimizing entropy generation per unit mass and distance during the transportation. With the increase of pipe diameter, the initial heating temperature of crude oil corresponded with the minimum entropy generation rate is decreased. The optimization design method of entropy generation minimization overcomes the shortcomings of design method in thermal economy optimization which needs the parameters in material prices, construction costs and something like that difficult to determine, and the result is affected by the price levels and interest rates.