Shell-side Heat Research Articles

Research on shell-side heat and mass transfer with multi-component in LNG spiral-wound heat exchanger under sloshing conditions

The spiral-wound heat exchanger (SWHE) is the primary low-temperature heat exchanger for large-scale LNG plants due to its high-pressure resistance, compact structure, and high heat exchange efficiency. This paper studied the shell-side heat and mass transfer characteristics of vapor-liquid two-phase mixed refrigerants in an SWHE by combining a multi-component model in FLUENT software with a customized multicomponent mass transfer model. Besides, the mathematical model under the sloshing condition was obtained through mathematical derivation, and the corresponding UDF code was loaded into FLUENT as the momentum source term. The results under the sloshing conditions were compared with the relevant parameters under the steady-state condition. The shell-side heat and mass transfer characteristics of the SWHE were investigated by adjusting the component ratio and other working conditions. It was found that the sloshing conditions enhance the heat transfer performance and sometimes have insignificant effects. The sloshing condition is beneficial to reduce the flow resistance. The comprehensive performance of multi-component refrigerants has been improved and the improvement is more significant under sloshing conditions, considering both the heat transfer and pressure drop. These results will provide theoretical support for the research and design of multi-component heat and mass transfer enhancement of LNG SWHE under ocean sloshing conditions.

Shell-Side Flow Condensation Heat Transfer on Three-Dimensional Enhanced Surface

Abstract An experimental investigation of shell-side flow condensation was performed on three-dimensional surface enhanced tubes, including a herringbone micro-fin tube and a newly developed 1-EHT tube. An equivalent plain tube was also tested for performance comparison. All the test tubes had similar geometry parameters, i.e., inner diameter 11.43 mm and outer diameter 12.7 mm. The outer shell diameter was 24.5 mm with a wall thickness of 0.6 mm. Tests were conducted using R410A as the working fluid at a dew point of 45 °C. The mass flux range of 10–55 kg/(m2 · s) with an inlet quality of 0.8 and an outlet quality of 0.1. Experimental results showed that the plain tube exhibited a better condensation heat transfer performance. Moreover, the mass flux had a significant influence on the heat transfer coefficient for shell-side condensation. A new prediction model based on the Cavallini’s equation was developed to predict the condensing coefficient where the mean absolute error is less than 4%.

Application of neural network model for predicting fouling behaviour of a shell and tube heat exchanger

The artificial neural network (ANN) is used as a significant tool in various industrial applications dealing with thermal problems during past few years. The purpose of the present work is application of ANN for heat transfer analysis of a shell and tube heat exchanger subjected to fouling. With the available experimental data, the network configuration was trained and tested. The outlet temperature differences both on shell and tube side and the exchanger efficiency were predicted by using neural network approach. This paper uses cleanliness factor as a tool for investigation of the performance of a heat exchanger due to fouling. Information criteria have been used for selection of relevant input variables and determination of optimal NN model structures. The root mean square error (RMSE) of the predictions in tube and shell side temperature difference and heat exchanger efficiency of 3.1°C, 2.2°C and 7.26% respectively illustrate that the model is adequately accurate. The closeness of experimental results with predicted results justify the correctness of neural network in the heat transfer analysis of a heat exchanger. Hence, it can be recommended that the ANN methodology can be successfully used to predict the performances of a shell and tube heat exchanger in industrial applications.

Numerical Simulation of a Shell-and-Tube Heat Exchanger with Special Form Helical Baffles

A new type of helical baffles heat exchanger is presented in this paper. Comparative study, through numerical simulation, was undertook between the new helical baffles heat exchanger and segmental baffle board heat exchanger in shell side flow and heat exchange characteristics. Fluid medium in the shell side is air. At the same velocity in the same flow conditions, pressure drop of helical baffles heat exchangers fell by an average of 26.8% compared with segmental baffle board heat exchangers, and the unit pressure drop of the heat transfer ratio of helical baffles heat exchanger increased by an average of 40.6%.

The Numerical Simulation of the Shell Side Flow and Heat Transfer for 600MW Steam Turbine Condenser

Detailed prediction of steam flow field and heat transfer process is significant for the condensers. The flow and heat transfer performance of the condenser of 600MW power unit is numerical simulated. A model of porous media with distributed resistance and mass sink is used to simulate the function of the tube bundle. The equations including the continuous, momentum and air concentration are numerically solved using the finite control-volume integration method and SIMPLE algorithm. The distribution of steam velocity, pressure, heat transfer coefficient and air concentration are obtained and analyzed. On the basis of results, the condenser is evaluated.

Simulation of Shell-Side Performance of Novel Heat Exchanger

Numerical simulation of shell-and-tube heat exchangers with novel helical baffles was carried out by using commercial codes to study shell-side flow and heat transfer characteristics. The results show that compared with shell-and-tube heat exchangers with conventional helical baffles, the ones with novel helical baffles can efficiently reduce the leakage from triangle zone so that the distributions of both the velocity field and heat transfer on tubes are more uniform. The comparison of comprehensive performance which is evaluated by heat transfer coefficient per unit pressure drop between conventional helical baffles and novel ones indicates that the latter performs better.

Effect of Inundation Upon the Condensation Heat Transfer Performance of R-134a: Part I—Facility Overview and Data Analysis (RP-984)

An experimental facility was designed and constructed to measure shell-side condensation heat transfer data for R-134a condensing on three different tube types: a smooth tube, a two-dimensional tube, and a three-dimensional tube. The 1575 fin-per-meter tubes had an equivalent or nominal outside diameter of 19.1 mm. Twenty-five tubes were arranged in a three-column by ten-row staggered pattern with a horizontal and vertical pitch of 22.9 mm. The facility was designed to operate at saturation temperatures of 35°C and 40°C over a heat flux range of 7500 to 63000 W/m2. This paper presents a detailed facility description, the facility operating procedure, data analysis, and uncertainty analysis. Experimental results from this study are presented in a companion paper (Part II).

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.

Development of a Method to Evaluate the Design Performance of a Feedwater Heater With a Short Drain Cooler

A method is developed to determine the shell and tube side heat transfer performance of a feedwater heater with a short drain cooler. The desuperheating, condensing, and drain cooling zones are discussed and analyzed by deriving a modified version of the Delaware Method of Shell-Side Design.

Local characteristics of shell-side liquid metal heat exchangers

The basic effect of lowering the inlet to 150 mm is a noticeable reduction in the inhomogeneity of the flow distribution along the depth and height of the mockup. Conditions, close to those for stabilized flow, were created at 150 mm from the upper edge of the inlet, thanks to which a section of low variation of the flow with channel length (250 mm ~ s ~ 600 mm) was observed in a significant part of the zone of "closed" cross sections. The flow inhomogeneity in a series of mockups decreased to a value vmax/v min = 1.7 instead of 3 in mockups with an inlet height of 350 mm (the section length s is 500 mm and 300 n~n in Figs. la and ib, respectively). If the inlet is wide (Hin/H r = 2), inertial effects are insignificant and the flow is close to "potential" flow with a maximum velocity (wmax/w = 1.19) at Power Physics Institute (FEI). Translated from Atomnaya Energiya, Vol. 71, No. 2,'pp.