The Role of the Ceramic Heat Exchanger in Energy and Resource Conservation

1980 ◽  
Vol 102 (2) ◽  
pp. 303-315 ◽  
Author(s):  
C. F. McDonald

The approaching era of strict energy conservation and eventual energy shortage will have a profound effect on the design of process and power-producing plants, since in the future maximum fuel utilization efficiency will be of the essence. The intrinsic economic worth of industrial reject and exhaust heat is too great to merely discharge to the environment, and means of utilizing this energy by improved process efficiency, or by cogeneration, must be quickly brought to the commercial stage. For future power conversion systems, and in particular open- and closed-cycle gas turbines, emphasis will be placed on maximizing efficiency, and in many cases this can be achieved only by significant increases in operating temperatures. For future gas turbines, process heat plants, chemical plants, basic industries, and waste heat recovery applications, the high level of reject temperature will necessitate the utilization of ceramic heat exchangers for thermal energy recovery. In this paper, current development activities in the field of ceramic heat exchangers for gas turbine applications are discussed, and it is projected that the encouraging results from these programs will stimulate a broader interest in high-temperature waste heat energy recovery. The future role the ceramic heat exchanger will play in energy recovery for different industrial applications is emphasized, and appropriate heat exchanger design criteria, types of construction, surface geometries, and development activities are briefly discussed.

Author(s):  
C. F. McDonald

Increased emphasis is being placed on the regenerative gas turbine cycle, and the utilization of waste heat recovery systems, for improved thermal efficiency. For such systems there are modes of engine operation, where it is possible for a metal fire to occur in the exhaust heat exchanger. This paper is intended as an introduction to the subject, more from an engineering, than metallurgical standpoint, and includes a description of a series of simple tests to acquire an understanding of the problem for a particular application. Some engine operational procedures, and design features, aimed at minimizing the costly and dangerous occurrence of gas turbine heat exchanger fires, are briefly mentioned.


Author(s):  
Russell V. Hoffman

This paper discusses the commercial and industrial applications of the AiResearch Model 831 Turbopower Module. The 500-hp turbine is described with particular emphasis upon the functional and control characteristics that have gained for it an enviable place in the energy-conversion field. Accessory equipment such as exhaust heat exchangers, absorption chillers, and turbopowered compressors are described in sufficient detail to enable the reader to understand their operation. Three typical commercial and industrial applications are described with particular emphasis on illustrating the economic feasibility of these on-site turbopowered energy systems. The results of the successful application of turbo-powered energy systems are tabulated.


1983 ◽  
Vol 24 ◽  
Author(s):  
C. H. Carter ◽  
J. Bentley ◽  
Robert F. Davis

Silicon carbide (SiC) possesses extreme hardness, very good electrical, thermal and mechanical properties as well as excellent resistance to corrosion and thermal shock. As such, it is one of the primary candidate materials for use in systems for the production and conversion of energy at elevated temperatures. It is currently employed in or being considered for use in heat exchangers or waste heat recouperators in various prototype fossile fuel systems. Specific examples of its potential use include (1) indirectly fired turbine engines wherein the turbine section is separated and protected from the combustor by a SiC heat exchanger; (2) coal fired systems which heat air in a fluidized bed containing a SiC heat exchanger; (3) coal gasifiers wherein the outlet channels will be of SiC because of the particle erosion, high temperatures (1673K) and pressures on these systems; (4) critical parts for gas turbines, the Sterling engine and adiabatic diesel engines; (5) high temperature bearings and (6) first wall materials for fusion reactors.


2012 ◽  
Vol 204-208 ◽  
pp. 4229-4233 ◽  
Author(s):  
Fang Tian Sun ◽  
Na Wang ◽  
Yun Ze Fan ◽  
De Ying Li

Drain water at 35°C was directly discharged into sewer in most of barbershop with Electric water heater. Heat utilization efficiency is lower, and energy grade match between input and output is not appropriate in most of barbershops. Two waste heat recovery systems were presented according to the heat utilization characteristics of barbershops and principle of cascade utilization of energy. One was the waste heat recovery system by water-to-water heat exchanger (WHR-HE), and the other is the waste heat recovery system by water-to-water heat exchanger and high-temperature heat pump (WHR-CHEHP). The two heat recovery systems were analyzed by the first and second Laws of thermodynamic. The analyzed results show that the energy consumption can be reduced about 75% for HR-HE, and about 98% for WHR-CHEHP. Both WHR-HE and WHR-CHEHP are with better energy-saving effect and economic benefits.


Author(s):  
H. Zabiri ◽  
V. R. Radhakrishnan ◽  
M. Ramasamy ◽  
N. M. Ramli ◽  
V. Do Thanh ◽  
...  

The Crude Preheat Train (CPT) is a set of large heat exchangers which recover the waste heat from product streams back to preheat the crude oil. The overall heat transfer coefficient in these heat exchangers may be significantly reduced due to fouling. One of the major impacts of fouling in CPT operation is the reduced heat transfer efficiency. The objective of this paper is to develop a predictive model using statistical methods which can a priori predict the rate of the fouling and the decrease in heat transfer efficiency in a heat exchanger in a crude preheat train. This predictive model will then be integrated into a preventive maintenance diagnostic tool to plan the cleaning of the heat exchanger to remove the fouling and bring back the heat exchanger efficiency to their peak values. The fouling model was developed using historical plant operating data and is based on Neural Network. Results show that the predictive model is able to predict the shell and tube outlet temperatures with excellent accuracy, where the Root Mean Square Error (RMSE) obtained is less than 1%, correlation coefficient R2 of approximately 0.98 and Correct Directional Change (CDC) values of more than 90%. A preliminary case study shows promising indication that the predictive model may be integrated into a preventive maintenance scheduling for the heat exchanger cleaning.


Heat exchangers are prominent industrial applications where engineering science of heat transfer and Mass transfer occurs. It is a contrivance where transfer of energy occurs to get output in the form of energy transfer. This paper aims at finding a solution to improve the thermal performance in a heat exchanger by using passive method techniques. This experimental and numerical analysis deals with finding the temperature outlets of cold and hot fluid for different mass flow rates and also pressure drop in the tube and the annular side by adding an elliptical leaf strip in the pipe at various angles. The single elliptical leaf used in experiment has major to minor axes ratios as 2:1 and distance of 50 mm between two leaves are arranged at different angular orientations from 0 0 to 1800 with 100 intervals. Since it’s not possible to find the heat transfer rates and pressure drops at every orientation of elliptical leaf so a generalized regression neural network (GRNN) prediction tool is used to get outputs with given inputs to avoid experimentation. GRNN is a statistical method of determining the relationship between dependent and independent variables. The values obtained from experimentation and GRNN nearly had precise values to each other. This analysis is a small step in regard with encomiastic approach for enhancement in performance of heat exchangers


2019 ◽  
Vol 38 (1) ◽  
pp. 115
Author(s):  
Aleksandar Kosta Anastasovski

Drying processes are one of the main consumers of heat energy in production. Any decreases in heat consumption during the drying process will considerably decrease production costs. This study analyzes the high consumption of heat in the drying of baker`s yeast. The main task is to minimize the energy demand and lower the price of the final products with partial heat recovery. These changes will require system modifications. One of the most popular and effective methods that can be used in this case is heat process integration with Pinch Technology. In this study, a reference system was simulated with a mathematical model and analyzed for waste heat streams.This paper suggests the redesigning of a drying system for production of active dry yeast.  Selected streams that satisfy conditions for heat process integration were involved in the evaluation for a better solution. Two different scenarios were proposed as possible solutions. The suggested solutions are retrofit designs of Heat Exchanger Networks. These Heat Exchanger Networks include already installed heat exchangers as well as new heat transfer units. The selection of better design was made with economic analysis of investment. The proposed scenarios of the analyzed sub-system give improvement in heat energy recovery. The best determined solution reduces the cost and thus has the highest profitability, but not the highest heat energy recovery.


2009 ◽  
Vol 13 (4) ◽  
pp. 41-48
Author(s):  
Zheshu Ma ◽  
Zhenhuan Zhu

Indirectly or externally-fired gas-turbines (IFGT or EFGT) are novel technology under development for small and medium scale combined power and heat supplies in combination with micro gas turbine technologies mainly for the utilization of the waste heat from the turbine in a recuperative process and the possibility of burning biomass or 'dirty' fuel by employing a high temperature heat exchanger to avoid the combustion gases passing through the turbine. In this paper, by assuming that all fluid friction losses in the compressor and turbine are quantified by a corresponding isentropic efficiency and all global irreversibilities in the high temperature heat exchanger are taken into account by an effective efficiency, a one dimensional model including power output and cycle efficiency formulation is derived for a class of real IFGT cycles. To illustrate and analyze the effect of operational parameters on IFGT efficiency, detailed numerical analysis and figures are produced. The results summarized by figures show that IFGT cycles are most efficient under low compression ratio ranges (3.0-6.0) and fit for low power output circumstances integrating with micro gas turbine technology. The model derived can be used to analyze and forecast performance of real IFGT configurations.


1978 ◽  
Author(s):  
C. F. McDonald

With soaring fuel costs and diminishing clean fuel availability, the efficiency of the industrial gas turbine must be improved by utilizing the exhaust waste heat by either incorporating a recuperator or by co-generation, or both. In the future, gas turbines for power generation should be capable of operation on fuels hitherto not exploited in this prime-mover, i.e., coal and nuclear fuel. The recuperative gas turbine can be used for open-cycle, indirect cycle, and closed-cycle applications, the latter now receiving renewed attention because of its adaptability to both fossil (coal) and nuclear (high temperature gas-cooled reactor) heat sources. All of these prime-movers require a viable high temperature heat exchanger for high plant efficiency. In this paper, emphasis is placed on the increasingly important role of the recuperator and the complete spectrum of recuperative gas turbine applications is surveyed, from lightweight propulsion engines, through vehicular and industrial prime-movers, to the large utility size nuclear closed-cycle gas turbine. For each application, the appropriate design criteria, types of recuperator construction (plate-fin or tubular etc.), and heat exchanger material (metal or ceramic) are briefly discussed.


Author(s):  
Soheil Soleimanikutanaei ◽  
Cheng-Xian Lin ◽  
Dexin Wang

Heat and water recovery using Transport Membrane Condenser (TMC) based heat exchangers is a promising technology in power generation industry. In this type of innovative heat exchangers the tube walls are made of a nano-porous material and have a high membrane selectivity which is able to extract condensate water from the flue gas in the presence of the other non-condensable gases such as CO2, O2 and N2. Considering the fact that for industrial applications, a matrix of TMC heat exchangers with several TMC modulus in the cross section or along the flow direction is necessary. Numerical simulation of multi-stage TMC heat exchanger units is of a great importance in terms of design, performance evaluation and optimization. In this work, performance of a two-stage TMC heat exchanger unit has been studied numerically using a multi-species transport model. In order to investigate the performance of the two-stage TMC heat exchanger unit, parametric study on the effect of transversal and longitudinal pitches in terms of heat transfer, pressure drop and condensation rate inside the heat exchangers have been carried out. The results indicate that the heat transfer and condensation rates both increase by reducing TMC tube pitches in the second stage and increasing the number of TMC tube pitches in the first stage of the units.


Sign in / Sign up

Export Citation Format

Share Document