Numerical Research On Deaerating Effect In The Thermal Deaerator

Dissolved oxygen is one of the main reasons causing corrosion in heating equipment. Therefore, deaeration is the key link in water treatment processes. To extend the service life of the thermal equipment, dissolved oxygen in water should be removed in engineering.In this paper, more convenient and general oxygen calculating formulas are fitted, according to the common form of oxygen, and comparing and analyzing the oxygen calculations of the literature. Based on the platform of FORTRAN, the oxygen calculating formulas are written as program. The program has been tested and verified. It can satisfy the engineering requirements.In the paper, the feasibility of two-phase flow model applied to the thermal deaerator is researched based on the platform of FLUENT. The Volume of Fluid model can simulate this physical phenomenon better. By the method of numerical simulation, the distribution of the pressure and the temperature has been obtained. The distribution of dissolved oxygen in water should be got by the oxygen calculation program. The deaerating effect is analyzed and discussed through the positions of the steam heating pipe, the outgassing height and different arrangements of heating pipes when adopting multi-tube heating. The results are as follows. Three positions of the steam heating pipe are studied, which are close to the baffle, in the middle, close to the right wall of the deaerator. The closer the location of heating pipe is to the baffle, the better the deaerating effect is. The outgassing height can affect the deaerating effect. Among the three discussed height, the middle height is best. The oxygen content is higher at the water export, and the corruption to the followed equipment is higher, when the outgassing height is lower or higher. Multi-tube heating should be used, according to the required heat flux and engineering constraints, in order to achieve the engineering requirements of oxygen content after deaeration. The oxygen content is higher at the region between the two heating pipes when the symmetrical arrangement of two heating pipes has been lay out. It will be lower at the bottom of the container and lower at the export at the same time. And the corruption to the followed equipment is lower.