Numerical study on the erosion process of the low temperature economizer using computational fluid dynamics-discrete particle method

The erosion process of the low temperature economizer (LTE) caused by the impact of the solid dust particles is numerically investigated using coupled computational fluid dynamics-discrete particle method. The coupled model is first validated via the experimental data of gas-solid flows in a square bend made from steel, liquid-solid flows in three sharp elbows made from 13% chrome steel, 25% chrome steel and Inconel 718 and gas-solid flows in a round bend made from aluminium, respectively. Then, numerical simulations are conducted on the LTE and the effects of the key parameters on the erosion process are discussed. The results show that the flue gas corridor plays a key role in affecting the erosion on the LTE. The erosion on the pipe system along the flow direction can mainly be divided into three regions containing a valley, a peak and a constant value with fluctuations, respectively. The division of the three regions is not influenced by the gas velocity or mass fraction, however, it can be very sensitive to particle size. Meanwhile, the exact degree of erosion increases with gas velocity, mass fraction and particle size. Finally, methods are proposed to reduce the erosion on the LTE by optimizing the pipe structure as well as the flue gas corridor.