Research on performance improvement of steam injector used in heating system

The profile of the (existing) minimum temperature difference between supply-water and backwater was protracted according to the need of heating system in different regions. The minimum temperature difference between supply-water and backwater increases from 6.37°C to 14.13°C with the increase of the designed environment temperature and the temperature difference between supply-water and backwater decreases with the environment temperature increasing in one firmed region. The steam injector with double infall, a modification of the existing steam injector was proposed to solve the problem that the existing steam injector can not meet the need-of the heating system during the whole period of heating. The mathematical model for the performance of the steam injector with double infall was set up. The calculation and research results show that with the steam pressure change from 0.3-0.6 MPa, the supply-water pressure could be higher than 0.4 MPa and the temperature difference between supply-water and backwater changes in the range of 14-25°C. So the steam injector with double infall could meet the needs of heating system better by changing the steam pressure.