The objective of the project was to verify the hot water generator design by ensuring that the operation conditions are met based on actual experimental results of combustion, heat transfer and fluid flow through the combustion chamber and pipes. CFD Analysis was done to simulate the combustion and flow of hot flue gases through the combustion chamber, hot water generator and economizer till the exhaust and to calculate the temperature of water passing through the heat exchanger pipes as it comes out of the water outlet. Suggestions were given based on the simulation result to enhance turbulence in the fluid flowing inside the tube.
The proposed design uses the Lamont type hot water generator. The hot water generator has a rectangular box type construction which has an economizer over the top and it finally connects to the exhaust draft tube. The meshing scheme is used to distribute the mesh uniformly in the outer region and a very fine mesh in the central core region is used. The figure shows the geometry created and the meshing scheme used for this geometry.
After the analysis was done it was verified that the operating conditions of the hot water generator was similar to the actual experimental results of combustion, heat transfer and fluid flow through the combustion chamber and pipes. The total volume flow rate of water entering the hot water generator is 900 GPM. The economizer is designed to ensure that the water enters the inlet drums located at the bottom of the hot water generator at 1600F – 1800F. The temperature in the core combusting region is high and progressively reduces through the heat exchange region as it is carried away by the water and the flue gases. The positions of the baffles were clearly understood from the flow.
