Development of New Heat Exchanger Design

2011 ◽  
Author(s):  
Anthony Couzinet ◽  
Daniel Pierrat ◽  
Laurent Gros ◽  
Thierry Kunc ◽  
Antoine Foata
Keyword(s):  
Heat Exchanger ◽  
Operating Conditions ◽  
Temperature Gradients ◽  
Computational Grids ◽  
Computational Time ◽  
Test Rig ◽  
Heat Exchanger Design ◽  
Numerical Predictions ◽  
Tube Banks ◽  
Heat Transfers

This study deals with a new heat exchanger design developed by DGA Essais propulseurs [inventor: A. Foata - patents 1–4] which should improve heat transfer compared with standard gas to liquid exchangers tube banks, present better compactness without weighing down the drop loss and ensure the behaviour under drastic operating conditions (1600°C and Mach 2). This new design is based on a bundle composed of nine pairs of spiral tubes which are one to one angular drifted. The predictions of the thermal performances are so fussy whatsoever by using experimental test rig or CFD computations. On one hand, the test rig doesn’t allow to fulfil the entire range of operating conditions. And yet the standard operating conditions can shade the influence of temperature gradients on the aero thermal behaviour of the spiral bundles. On the other hand, in order to obtain reliable numerical predictions of heat transfers, the spiral bundle meshing refinement is crucial to simulate accurately the flow structure and the temperature gradients close to the inner walls. Moreover, if the grooves are explicitly taken into account in the numerical model, the computational grids required will be too fine to guarantee realistic computational time. So firstly, experimental and numerical approaches are used jointly in order to show the new heat exchanger design is sustainable. Optimization of the heat exchanger will be performed in the next phase of this study.

Performance Monitoring of Gas Turbine Components: A Real Case Study Using a Micro Gas Turbine Test Rig

2009 ◽  
Author(s):  
Silvio Cafaro ◽  
Alberto Traverso ◽  
Mario L. Ferrari ◽  
Aristide F. Massardo
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Performance Monitoring ◽  
Operating Conditions ◽  
Vibration Sensor ◽  
Diagnostic Model ◽  
Test Rig ◽  
Micro Gas Turbine ◽  
Distributed Power Generation ◽  
Heat Exchanger Design

Estimating the performance of all the components of a recuperated micro gas turbine cycle plays a determinant role in improving their reliability for distributed power generation and cogeneration. The monitoring and diagnostic activity consists in continuously evaluating the productivity capacity and the efficiency of the plant, using the stream of data coming from the plant’s instrumentation. In this framework a diagnostic tool for the micro gas turbine installed at the TPG test rig (located in Savona, Italy) was developed, with the objective of monitoring the operating parameters of the turbomachine, the performance of the heat exchanger and, in general, the good operation of the plant. Even though the commercial machine is equipped with the essential probes for control (rotational speed, TOT, intake temperature and eating water temperature meters) and diagnostic purposes (vibration sensor, filter differential pressure and other thermocouples), further instruments were introduced in the test rig to measure a larger number of properties and points. As result of this, a wide number of measurements is available and can be effectively used for the development of a diagnostic model. The diagnostic model presented in this paper is written in Matlab-Simulink® environment and, in its first version, provides information about compressor and turbine efficiency and heat exchanger effectiveness. The model was developed starting from the turbomachinery maps and the heat exchanger design performance. A validation of the code was performed using the measurements coming directly from the data acquisition system. Preliminary results coming from the model are presented, showing the different performance of each component of the plant in the various operating conditions.

Impact of Manifold Design on Heat Exchanger Efficiency

1997 ◽  
Vol 119 (2) ◽  
pp. 357-362
Author(s):  
D. K. Harris ◽  
D. G. Warren ◽  
V. W. Goldschmidt
Keyword(s):  
Heat Exchanger ◽  
Internal Flow ◽  
Heating System ◽  
Operating Conditions ◽  
Baseline Design ◽  
System A ◽  
Numerical Predictions ◽  
Forced Air ◽  
And Behavior ◽  
The Impact

The impact of manifold design on single-phase heat exchanger effectiveness is studied using the NTU-Effectiveness method. Manifolds are devices that redistribute the internal flow stream of a heat exchanger from one to several passages. Two manifold types are identified: collector box and direct split designs. The particular application considered is that of a gas fired forced air heating system. A general enhancement analysis is performed which covers four different combinations of performance and objective criteria. Three cases involve increasing the heat exchanger effectiveness while constraining either the internal flow head loss, the internal mass flow rate, or their product. The other case involves reducing the required heat exchanger flow length while constraining the heat transfer rate. Familiar convection correlations are then incorporated into the enhancement analysis to predict general trends and behavior when the main tube is split into several smaller tubes. Analytical estimates of improved effectiveness are presented for three operating conditions of an actual heat exchanger which possesses a manifold. Experimental data acquired from the gas-to-gas heat exchanger are compared to numerical predictions of its performance without a manifold (baseline design). The analytical equations developed closely predict the improvement in heat exchanger effectiveness.

Heat Exchanger Design of Direct Evaporative Cooler Based on Outdoor and Indoor Environmental Conditions

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
Neda Gilani ◽  
Amin Haghighi Poshtiri
Keyword(s):  
Heat Exchanger ◽  
Thermal Comfort ◽  
Indoor Air ◽  
Ambient Air ◽  
Operating Conditions ◽  
Design Guideline ◽  
Heat Exchanger Design ◽  
Evaporative Cooler ◽  
Direct Evaporative Cooler ◽  
Comfort Criteria

Performance of a direct evaporative cooler (DEC) was numerically studied at various outdoor and indoor air conditions, with geometric and physical characteristics of it being extracted based on thermal comfort criteria. For this purpose, a mathematical model was utilized based on the equations of mass, momentum, and energy conservation to determine heat and mass transfer characteristics of the system. It is found that the DEC can provide thermal comfort conditions when the outdoor air temperature and relative humidity (RH) are in the range of 27–41 °C and 10–60%, respectively. The findings also revealed that by raising the RH of ambient air, the system will reach the maximum allowed RH faster and hence a smaller heat exchanger can be used when the ambient air has higher RH. Finally, performance of the DEC in a central province of Iran was investigated, and a design guideline was proposed to determine size of the required plate heat exchangers at various operating conditions.

Optimization of the Fin-and-Tube Heat Exchanger Design for Non-Standard Applications

2010 ◽  
Author(s):  
Janybek Orozaliev ◽  
Christian Budig ◽  
Klaus Vajen
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Optimization Procedure ◽  
Operating Conditions ◽  
Genetic Optimization ◽  
Tube Heat Exchanger ◽  
Heat Exchanger Design ◽  
Standard Application ◽  
Friction Performance ◽  
Genetic Optimization Algorithm

This paper describes an optimization procedure of the heat exchanger design, which is based on cost effectiveness. In the procedure, a genetic optimization algorithm varies the heat exchanger geometry and operating conditions. The influence of the heat exchanger design on its costs, heat transfer and friction performance has been evaluated economically by determining investment and operation costs of the system. For this purpose, a specific approach for setting up of cost functions of the heat exchanger, fans and pumps is presented as well. It has been shown on a non-standard application, that the heat transfer costs of the optimized heat exchanger design is 30% lower than that of the reference configuration, which was designed by a heat exchanger producer.

High Temperature Heat Exchangers (HTHX) for Nuclear Applications

2006 ◽  
Author(s):  
James C. Govern ◽  
Cila V. Herman ◽  
Dennis C. Nagle
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Operating Conditions ◽  
Heat Exchanger Design ◽  
Performance Requirements ◽  
Starting Point ◽  
Temperature Heat ◽  
And Performance ◽  
Design Challenges

Many nuclear engineering applications, current and future, require heat exchangers operating at high temperatures. The operating conditions and performance requirements of these heat exchangers present special design challenges. This paper considers these challenges with respect to a simple heat exchanger design manufactured of a novel carbon material. Heat transfer and effectiveness calculations are performed for several parametric studies regarding heat exchanger parameters. These results are used to better understand the design challenges of high temperature heat exchangers as well as provide a starting point for future optimization work on more complex heat exchanger designs.

Advanced Heat Exchange Technology for Thermoelectric Cooling Devices

1998 ◽  
Vol 120 (1) ◽  
pp. 98-105 ◽  
Author(s):  
R. L. Webb ◽  
M. D. Gilley ◽  
V. Zarnescu
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
High Performance ◽  
Operating Conditions ◽  
Heat Sources ◽  
Thermoelectric Coolers ◽  
Heat Exchanger Design ◽  
Cooling Devices ◽  
Conventional Technology ◽  
Current Heat

Thermoelectric coolers (TEC) are potentially ideal devices to cool electronic components or small electronic enclosures. However, practical heat exchange can limit the COP and restrict the range of useful applications. The TEC must reject heat from the hot side to the ambient, which is typically air. The COP can be increased by reducing the hot-side temperature, which requires a high-performance heat exchanger. An understanding of the heat sources in the TEC is presented, and relations are presented to define the hot-side thermal resistance required to operate at desired operating conditions. A novel air-cooled thermosyphon reboiler-condenser system has been developed that promises significantly higher COP for thermoelectric coolers than is possible with current heat exchange technology. This heat exchanger design concept is described and compared to conventional technology.

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