Structural Optimization for Stator Radial Ventilation Cooling System of Turbo Generator

2014 ◽  
Vol 1039 ◽  
pp. 65-68
Author(s):  
Jun Wang ◽  
Gui Qin Li ◽  
Guo Jun Xu ◽  
Hong Bo Li ◽  
Xiao Yuan
Keyword(s):  
Material Flow ◽  
Radial Flow ◽  
Cooling System ◽  
Radial Distance ◽  
Flow Distribution ◽  
Structure Optimization ◽  
Turbo Generator ◽  
Flow Deviation ◽  
Outlet Flow ◽  
Flow Pressure

For 300 MW inner cooling turbo generator, a discrete model for cooling material flow distribution of radial ventilation cooling system has been developed. The structure optimization is studied with this model. The effect of the radial distance and the tangential distance on stator’s radial flow distribution was analyzed and optimized. The results of the simulation show that with the same inlet-outlet flow pressure the flow deviation increased as the radial distance increased but the tangential distance decreased oppositely.

scholarly journals Two-dimensional oscillations in divergent jets of compressible fluid

1934 ◽  
Vol 145 (854) ◽  
pp. 52-71 ◽  
Keyword(s):  
Compressible Fluid ◽  
Radial Flow ◽  
Fluid Motion ◽  
Radial Distance ◽  
Two Dimensions ◽  
Common Point ◽  
Compressible Fluids ◽  
Fluid Density ◽  
Straight Lines ◽  
Steady Velocity

1. The problem of determining the possible modes of stationary oscillation for a compressible fluid, moving with a steady velocity which is not constant, usually presents great difficulties. One case which is to some extent amenable to analysis is that of uniform radial flow in two dimensions, where the undisturbed paths of the fluid particles are straight lines radiating from a common point or source. The term “source” is here used somewhat loosely, for in the solution which will be given it is found that the fluid density attains unreal values inside a certain circle having its centre at this common point. It is well known that in radial flow two systems of velocity are possible to a compressible fluid—namely, either (i) zero velocity at r = ∞, and an increasing but limited velocity as the radial distance from the source decreases ( i. e. , a modified “perfect fluid” motion); or (ii) the maximum possible velocity at infinity (corresponding with zero pressure and density), and a decreasing speed—also limited—as r decreases. This type of flow is peculiar to compressible fluids.

Effect of Geometric Parameters on the Performance of a Radial Flow Pressure Exchange Ejector

2010 ◽  
Author(s):  
Muhammad Umar ◽  
Charles A. Garris
Keyword(s):  
High Pressure ◽  
Radial Flow ◽  
Energy Levels ◽  
Cone Angle ◽  
Interface Pressure ◽  
Complex Flow ◽  
Transfer Energy ◽  
Two Fluids ◽  
Flow Pressure ◽  
Pressure Exchange

The “Pressure exchange” is a novel concept in turbomachinery whereby two fluids, at different energy levels, come in direct contact with each other to transfer energy and momentum between them through non-steady interface pressure forces. The rotating jets of the high pressure primary fluid, often referred to as pseudoblades, resemble solid blades on the impeller of a conventional turbomachine. The low pressure secondary fluid, ahead of the pseudoblades, is pressurized by the action of interface pressure forces. The current paper seeks to provide an insight into the complex flow phenomena occurring inside the radial flow pressure exchange ejector. This research presents the results of the first successful numerical simulation to explore the effects of spin angle, rotor cone angle and number of nozzles on the performance of a radial flow pressure exchange ejector. If this new concept is shown to be viable for gas compression at sufficiently high pressure ratios, then, in refrigeration applications, it would enable environmentally benign refrigerants to replace the harmful chlorofluorocarbons (CFC) and reduce the effluence of greenhouse gases. Applications in many other areas, where conventional ejectors are currently used, are also possible.

Numerical Investigation on the Characteristic of the Reverse Flow Phenomenon in a Z-Type Parallel Compact Heat Exchanger With Large Number of Tubes

2018 ◽  
Author(s):  
Jian Zhou ◽  
Ming Ding ◽  
Haozhi Bian ◽  
Yinxing Zhang ◽  
Zhongning Sun
Keyword(s):  
Heat Exchanger ◽  
Pressure Distribution ◽  
Coming Out ◽  
Heat Exchangers ◽  
Cooling System ◽  
Reverse Flow ◽  
Flow Distribution ◽  
Flow Phenomenon ◽  
Compact Heat Exchangers ◽  
Geometry Design

The parallel compact heat exchangers have been widely applied in the various fields such as heat exchangers in chemical engineering, the solar collector, fuel cells and the passive removal heat exchanger in passive containment cooling system (PCCS), etc. The heat exchangers in the PCCS removes out the heat brought by the steam coming out from the broken reactor or primary cooling system. Therefore, the performance of the passive containment cooling system heat exchanger (PCCS HX) will greatly influence the safety and integrity of the containment. In previous investigations on the parallel compact heat exchangers, attentions are focused on the pressure distribution and flow distribution in the heat exchangers. A bad flow distribution in the heat exchanger will reduce the heat performance. More seriously, the coolant in some tubes may boils and the tubes will be overheated, resulting in explosion of tubes. Therefore, the characteristic of pressure distribution and the flow distribution should be investigated for a uniform flow distribution. In the past studies of the compact heat exchangers, the numbers of tube are almost under 72 which is relatively small, while the number of tubes PCCS HX is usually over than 100. And the pressure distribution in compact heat exchangers is assumed that the pressure recovery plays a leading role. However, the more numbers of tube will bring more flow maldistribution, if the geometry design is selected inappropriately. The reverse flow may occur in the heat exchanger, which means that in some tubes, the coolant flows from the tube outlet to the inlet. This phenomenon of reverse flow have never been mentioned in previous studies. The occurrence of the reverse flow will significantly decrease the performance of the heat exchanger and cause a bad influence on the safety of the containment. In the PCCS, the Z-type heat exchanger is one of the choice of PCCS HX (heat exchanger) design. Therefore, the present study focus on the characteristic of reverse flow phenomenon in Z-type heat exchangers. The pressure distribution and the flow distribution have been separately investigated deeply. The conclusion of this study will provide a guide to the geometry design of the PCCS HX with large number of tubes.

Air flow distribution measurement of the vehicle cooling system test rig

2019 ◽  
Author(s):  
J. H. Lee ◽  
Z. A. Latiff ◽  
M. R. M. Perang ◽  
M. F. M. Said
Keyword(s):  
Cooling System ◽  
Air Flow ◽  
Flow Distribution ◽  
Test Rig ◽  
Distribution Measurement

Numerical Simulation of the Flow Field for Rotor Ventilation System of Large-Scale Nuclear Power Turbo-Generator

2012 ◽  
Vol 152-154 ◽  
pp. 1498-1504 ◽  
Author(s):  
Xiao Hu Zhang ◽  
Lei Hu ◽  
Jian Hua Yuan ◽  
Yi Chao Yuan
Keyword(s):  
Flow Field ◽  
Nuclear Power ◽  
Large Scale ◽  
Ventilation System ◽  
Flow Distribution ◽  
Basic Unit ◽  
Turbo Generator ◽  
Key Issues ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance

The nuclear power turbo-generator with large capacity is a basic unit of nuclear power plant, while the cooling technology becomes one of the key issues which affect its design and operation deeply. Axial-radial ventilation structure for rotor is commonly used in large nuclear power generator. In this article, according to the basic principles of computational fluid dynamics (CFD), ventilation’s structure and performance is analyzed, 3D flow model is also established. After the boundary conditions are determined, the numerical calculation and analysis is finished. And then, the rules of flow distribution is obtained, the flow field and the static pressure character of the gap is also computed, which could be very important to the ventilation system of the whole generator.

A Numerical Study of Flow and Temperature Maldistribution in a Parallel Microchannel System for Heat Removal in Microelectronic Devices

2012 ◽  
Author(s):  
Manoj Siva ◽  
Arvind Pattamatta ◽  
Sarit Kumar Das
Keyword(s):  
Heat Exchanger ◽  
Cross Section ◽  
Design Theory ◽  
Cooling System ◽  
Search Algorithm ◽  
Numerical Study ◽  
Heat Removal ◽  
Flow Distribution ◽  
Microchannel Cooling ◽  
Flow Maldistribution

A common assumption in basic heat exchanger design theory is that fluid is distributed uniformly at the inlet of the exchanger on each fluid side and throughout the core. However in reality, uniform flow distribution is never achieved in a heat exchanger and is referred to as flow maldistribution. Flow maldistribution is generally well understood for the macrochannel system. But it is still unclear whether the assumptions underlying the flow distribution in conventional macrochannel heat exchangers hold good for microchannel system. In this regard, extensive numerical simulations are carried out in a ‘U’ type parallel micro-channel system in order to study flow and heat transfer maldistribution and validated with in-house experimental data. A detailed parametric analysis is carried out to characterize flow maldistribution in a microchannel system and to study the effect of geometrical factors such as number of channels, n, Area of cross section of the channel Ac, manifold cross section area Ap, and flow parameter such as Reynolds number, Re, on the pressure and temperature distribution. In order to minimize the variation in pressure and to reduce temperature hot spots in the microchannel, a Response surface based surrogate approximation (RSA) and a gradient based search algorithm are used to arrive at the best configuration of microchannel cooling system. A three level factorial design involving three parameters namely Ac/Ap, Re, n are considered. The results from the optimization indicate that the case of n = 5, Ac/Ap = 0.12, and Re = 100 is the best possible configuration to alleviate flow maldistribution and hotspot formation in microchannel cooling system.

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