Background: TPP operates technological systems for condensate return of steam from remote external consumers. In these systems, it is necessary to protect the metal from corrosion, as well as fulfill the requirements of regulatory documents on the concentration of iron compounds in the condensate. In such systems it is not possible to use effective thermal deaerators, however, it is promising to use deaerators of superheated water, for example, cavitation-jet deaerators. It is required to choose a rational implementation option for such a technical solution, and evaluate its effectiveness, that is, determine the effect of the work of a new system element - a deaerator - on the normalized chemical parameters of the returned condensate.
Materials and methods: To develop a mathematical description of the technological scheme for condensate return with a cavitation-jet deaerator, we used the previously proposed mathematical model of superheated water deaerators, as well as the well-known method for calculating the corrosion rate of return condensate pipelines. Evaluation of the effectiveness of the proposed technical solution is based on the developed model based on experimental data on medium-pressure thermal power plants.
Results: Rational implementation option selected, the main parameters are determined and the effectiveness of the technical solution providing for the use of cavitation-jet deaerators in condensate return systems of external consumers is justified. A mathematical description has been developed that allows you to determine the required performance of deaerators and the frequency of water recirculation through them in each mode. Based on the results of studies in relation to the actual conditions of thermal power plants, recommendations were developed for the effective application of the proposed technical solution in practice.
Conclusions: It is advisable to install a deaerator according to the recirculation scheme through the condensate collection tank. Compared to a sequential circuit, this solution allows to reduce capital costs, as well as to ensure the deaerator operates in the highest efficiency mode. The choice of the nominal performance of deaerators should be carried out taking into account daily schedules of changes in the flow rate of incoming condensate and the concentration of dissolved oxygen in it. In most operating modes of the system, it is possible to ensure compliance with the regulatory requirements for the mass concentration of corrosion products in the condensate returned to the TPP. The results can be used in the design of new and improving the efficiency of existing TPPs that supply steam to external consumers.