Research On Performance Of Experiment And Application Of Injecting Low-pressure Heater

Aiming at the existing problems of the tube low-pressure heater in power plant , this paper uses a new jetting low-pressure heater which can produce saturated water and plays a role in energy conservation.Low-pressure releasing steam or steam getting out of condensate or low-pressure steam of turbine exhaust can be used as heating source,so its has advantages of high thermal efficiency, simple thermal system, low cost, small footprint, long life, no vibration, low noise etc.The main inlet parameters tested -steam pressure , water pressure is in the range of 0.10MPa ~ 0.22MPa and 0.25 MPa ~ 0.5MPa, respectively.Refering the researchs of the water-steam injector, a double-stage injector is designed on the basis of the structure of the original single-stage injector, and heating performance of single and double stage injector has been compared.The results show that: through the experimental comparison, the injection coefficient of the second stage section opened was 32% higher than that of its closed. The performance of double-stage injector is better than that of the single-stage ejector , the injection coefficient of double-stage injector was 2 to 3 times more than that of a single-stage injector, and the injection coefficient is also measuring the main signs of the performance of injector.In the heating effect, the double-stage injector was more stable than the single-stage injector and its higher outlet water temperature can meet heating demand. In practical applications, the parameters of steam is often decided by the field parameters, generally not considering the methods of improving steam pressure to improve the performance of injector. when the single-stage injector can not meet the requirements of conditions, double-stage injector can be used, so it also shows using the double-stage is necessary and reasonable.Back pressure has a great impact on the outlet water temperature . When the back pressure was higher ,the outlet temperature was higher too, the higher outlet temperature can meet the requirements of removing oxygen under atmospheric pressure. Nozzle structure have a great impact on the injector performance, because on the basis of the fluid parameters and known empirical formula ,the designed structure of the nozzle is not necessarily the best.After designing the structure so well, in order to verify whether the parameters of fluid and structure are the best combination, it is necessary to amend its structure by experimental parameters. Designing the specific structure of jetting low-pressure heater, the knowledge of fluid dynamics should be used as far as possible, and to reduce pressure loss , the structure of a less solid wall and streamlined profile can be used . when the injector is processed and installed ,ensuring the accuracy of its processing and installation is critical.