Steam Surface Condensers Research Articles

In situ experimental study for the optimization of chlorine dosage in seawater cooling systems

The paper details an in situ study for the evaluation of the evolution of fouling heat transfer resistance and to optimize the antifouling chlorine dosage at a 550 MW power station. A portable pilot plant has been designed to simulate the steam surface condenser and used as an accurate fouling monitor that takes the seawater from the same intake point as the power station. This study includes fouling extraction and its characterization for different dosage patterns. The residual chlorine concentration at the cooling-water discharge from the power station is 0.2 mg/l and has been considered appropriate for the prevention of the formation of fouling, because with this concentration approximately 90% reduction in the amount of fouling is obtained. Residual chlorine dosages lower than 0.2 ppm could be effective in controlling fouling development if mechanical techniques of fouling control are also available.

Analysis of the thermal performance of a church window steam condenser for different operational conditions using three models

The results of the usual design model “Standards for Steam Surface Condensers (SSSC)” and those of a two-dimensional model (2D) and a three-dimensional model (3D) are presented. Both the 2D model and the 3D model allow the presence of non-condensable gases, the pressure drop across the tube bundle and the tube arrangement to be taken into account, while the SSSC model does not. In order to study the thermal performance of the models, the heat transfer rate and the condensate mass flow rate were analysed varying the circulating water inlet temperature and velocity, as well as the fouling inside the tubes. The 2D and 3D models behave similarly to the SSSC model, but present less dependence on temperature and velocity variations. Because of the low running time, both the SSSC and the 2D models are adequate for on-line fouling evaluation of the condenser, the latter affording a more detailed description of the condenser. The SSSC model and the 3D model can complement one another in the design stage, using the SSSC for the area estimation and improving the inner condenser geometry by means of the 3D model.

Application of a design code for estimating fouling on-line in a power plant condenser cooled by seawater

A study of the data that allows us to carry out heat balances as well as other important data needed to estimate fouling evolution for a seawater refrigerated condenser in a 550 MW power plant is presented. The data was collected during several months and subsequently analyzed. The goal was to test the utilization and reliability of indirect methods, such as those proposed by The Standards for Steam Surface Condensers (SSSC), to estimate fouling by means of the cleanliness factor in a condenser cooled by seawater. A review of the working conditions of the power plant was carried out, as well as of the conditions prescribed by manufacturers for the condenser evaluations. Most of the conditions were maintained to select the points or the times to be analyzed for the on-line evaluation of the cleanliness factor. The use of additional criteria for point selection was analyzed. These criteria are useful in order to obtain a clearer representation of the evolution of the cleanliness factor.

Numerical study of the performance of a church window tube bundle condenser

Two steam surface condenser design methods are compared: that of the Heat Exchange Institute Standards and a three-dimensional steady-state numerical model for simulating the flow, the heat and the mass transfer in this type of industrial equipment. In the numerical model, the study of the shell flow is carried out using a single-phase approach, the presence of the tubes is simulated through the porosity factor, and the heat and mass transfer processes are modelled using empirical correlations. The variables condenser pressure and overall heat transfer coefficient are analysed applying both methods. The influence on these variables of the steam mass flow rate from the turbine exhaust, the venting outlet pressure, the tube cleanliness factor, the inlet water temperature, and the water velocity is studied. The overall heat transfer coefficient is under-predicted with the numerical model, its value being 4.5–8.5% lower than that obtained using the Heat Exchange Institute Standards method.

Modelling of steam surface condenser using finite element methods

Two numerical procedures are proposed for surface condenser analysis. In the first method a two-noded element is used with a variable heat transfer coefficient for each element. This method is suitable for performance analysis under various operating conditions. A four-noded element is also proposed for studying the axial heat conduction effect in tubes. In the second method, shell side flow and heat transfer are simulated in order to study the flow distribution and pressure drop characteristics. The governing equations are solved in primitive variable form. The finite element method with a Eulerian velocity correction algorithm is used. These two procedures are applied to two different types of surface condensers and the results are found to be in good agreement with experimental data. © 1997 John Wiley & Sons, Ltd.

Sensitivity Analysis of Heat Transfer Coefficient Correlations on the Predictions of Steam Surface Condensers

The present study reports on an analysis of the sensitivity of condensation heat transfer coefficient correlations on the simulations of the performance of steam surface condensers. Five correlations of heat transfer coefficient for filmwise condensation are tested against the experimental data for a steam surface condenser. A quasi-three-dimensional approach is used to predict the fluid flow and heat transfer in the steam surface condenser. The governing equations are solved in primitive variable form using a semiimplicit consistent control-volume formulation in which a segregated pressure correction-linked algorithm is employed. The modeling of the geometries of condensers, including tube bundles and baffle plates, is carried out based on the porous media concept using flow, heat, and mass transfer resistances.

A Quasi-Three-Dimensional Approach to Predict the Performance of Steam Surface Condensers

Abstract A quasi-three-dimensional numerical procedure is proposed to simulate the fluid flow and heat transfer in the shell-side of steam surface condensers. The proposed procedure is applied to an experimental steam surface condenser to evaluate its predictive capability. The predicted results give good general agreement with the experimental data. The governing equations are solved in primitive variable form using a semi-implicit consistent control-volume formulation in which a segregated pressure correction linked algorithm is employed. The modeling of the geometries of condensers, including tube bundles and baffle plates, is carried out based on porous media concepts using flow, heat and mass transfer resistances.

Numerical Simulation of Different Types of Steam Surface Condensers

A numerical procedure is developed to simulate the fluid flow and heat transfer processes in the shell-side of steam surface condensers. The governing equations are solved in primitive variable form using a semi-implicit consistent control-volume formulation in which a segregated pressure correction linked algorithm is employed. The procedure is applied to three different types of surface condenser. The numerical predictions are critically assessed by comparison to available experimental data for condensers, and in general, the solutions are in good agreement with the experimental data.

A History of Steam Surface Condensers for the Electric Utility Industry

At the session entitled History and Evolution of Heat Exchanger Equipment and Standards at the ASME/AIChE 18th National Heat Transfer Conference, San Diego, California, August 6-8, 1979, various segments of the history of heat transfer devices were discussed by engineers who had themselves played significant roles in that history. Because of time, topics were limited to those involving shell-and-tube exchangers. One of these historical studies, Joe Sebald's history of the surface condenser, is presented in this issue. It provides an excellent record of the evolution of the modern surface condenser, which is in fact a spectacularly large, fixed, tube sheet shell-and-tube unit. The history of other types of heat transfer apparatus, as well as shell-and-tube exchangers, will appear in this column in future issues.

復水器の開発研究についての一つの提案

復水器の開発研究についての一つの提案

On the Surface Condensation of Steam

On the Surface Condensation of Steam

III. On the surface-condensation of steam

In the author’s experiments steam was passed into a tube, to the outside of which a stream of water was applied, by passing it along the concentric space between the steam-tube and a wider tube in which the steam-tube was placed. The steam-tube was connected at its lower end with a receiver to hold the condensed water. A mercury gauge indicated the pressure within the apparatus.

On the surface condensation of steam

On the surface condensation of steam

On the surface-condensation of steam

On the surface-condensation of steam

VIII. On the surface-condensation of steam

The laws which regulate the transmission of heat through thin plates of metal under various circumstances, although of extensive practical application, and although their elucidation would necessarily involve scientific conclusions of great interest, have hitherto received little of the attention of natural philosophers. Two great divisions of the inquiry are, first, the communication of heat from the products of combustion to a boiler; and second, the application of cold to a vessel employed for the condensation of steam. With a view to supply some information on the latter subject I have, with the assistance of a grant from the Royal Society, undertaken the present research.