Design of high-pressure direct contact heater for promising power supply units: Experimental substantiation
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- 作者：E. V. Somova ; A. L. Shvarts ; A. V. Turkin
- 关键词：flow diagram ; direct contact heater ; feed water ; experimental studies ; condensation ; high pressure
- 刊名：Thermal Engineering
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：63
- 期：11
- 页码：819-824
- 全文大小：620 KB
- 刊物类别：Engineering
- 刊物主题：Engineering Thermodynamics and Transport Phenomena
Russian Library of Science - 出版者：MAIK Nauka/Interperiodica distributed exclusively by Springer Science+Business Media LLC.
- ISSN：1555-6301
- 卷排序：63
文摘
The results of experimental studies of superheated steam condensation on feed water jets in a highpressure, direct-contact heat exchanger are presented. Direct contact feed water heater (DCFWH) can be used in a dual-flow diagram of a steam-power unit with ultrasupercritical steam parameters (35 MPa, 700/720°C). The direct contact feed water heater is included in the flow diagram of the II circuit in a promising power unit; it provides feed water heating to 340°C in all maintenance and emergency operation modes of the unit. The reliability of the high-pressure direct contact heater operation in this flow diagram is of major importance in relation to the danger of lead solidification in the tube space of the steam generator. Technical requirements to the design of the high-pressure direct contact heater for increasing the heat exchange efficiency are formulated based on the results of earlier studies with steam–water mixture as the heating medium. The results of studies of superheated steam condensation on jets presented in this study testify that feed water is additionally heated to the required temperature at the output of the installation. The influence of initial feed water parameters (outflow velocity and temperature) on the jet heating length is elucidated. The numerical approximation of the experimental data for determination of the jet heating length in the nominal and partial power unit loads is obtained. The results of the calculations are used to simplify the design of the water-supplying element for the direct contact feed water heater. The proposed design of direct contact feed water heater is characterized by simplicity and low metal intensity, which provides the installation reliability at the considered pressure level due to the minimum number of structural elements.