The Experts below are selected from a list of 602046 Experts worldwide ranked by ideXlab platform
Yang Chen - One of the best experts on this subject based on the ideXlab platform.
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Working Process Model of Rotary Vane Compressor
Computer Simulation, 2006Co-Authors: Yang ChenAbstract:A rotary vane compressor has many advantages such as simple construction, no eccentric rotary parts, small size and high volumetric efficiency, etc. So it is widely used in many fields. In this paper, the Working Process modeling of a rotary vane compressor for an automobile air conditioner is presented. The model is based on the common hypothesis: "The thermal status of the refrigerant in the chamber is uniform at any time". Based on the Working Process model, the distribution of the thermal parameters in the compressor chambers on several key positions is computed with Finite Element Method (FEM). It is shown that the parameter distribution in the compressor chambers is uniform on every important position. It is proved that the hypothesis for the Working Process model accords basically with the fact. And it could be used for engineering design and operating analysis.
Ziwen Xing - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation on the internal Working Process of a co2 rotary vane expander
Applied Thermal Engineering, 2009Co-Authors: Bingchun Yang, Xueyuan Peng, Bei Guo, Ziwen XingAbstract:Abstract This paper presents the experimental investigation on the internal Working Process especially the internal leakage of a rotary vane expander prototype, which was developed to replace the throttling valve to improve the Coefficient of Performance (COP) of the transcritical CO 2 refrigeration cycle. The pressure diagram as a function of the rotation angle ( p – θ diagram) was recorded by two pressure sensors arranged within the expansion chamber, based on which the features of the Working Process were analyzed and effects of the some improvement measures on the internal leakage were discussed. Compared with the ideal p – θ diagram, the recorded diagrams presented more rapid decrease in the pressure during expansion Process, which was attributed to serious leakage within the expander. Further analysis of the recorded p – θ diagrams showed that three adjacent vanes instead of two formed an integrated Working chamber, which implied that the in-between vane did not contact the cylinder wall at all, and this guess was proved by the high speed video recording of the running rotor together with the vanes during operation of the expander in CO 2 system. By arranging springs in the vane slots, tight contact between the vanes and the cylinder wall was ensured and hereby the Working Process was improved. The gap between the suction and discharge ports was another important leakage path and installation of a seal there could increase the pressure difference through the expander by 1.5–2.5 MPa by decreasing the leakage directly from the high-pressure suction chamber to the low-pressure discharge chamber. Performance test of the modified expander prototype with springs in the slots and seal at the seal arc showed that the volumetric efficiency increased from 17% to 30% and the isentropic efficiency from 9% to 23% at the speed of 800 rpm.
Bingchun Yang - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation on the internal Working Process of a co2 rotary vane expander
Applied Thermal Engineering, 2009Co-Authors: Bingchun Yang, Xueyuan Peng, Bei Guo, Ziwen XingAbstract:Abstract This paper presents the experimental investigation on the internal Working Process especially the internal leakage of a rotary vane expander prototype, which was developed to replace the throttling valve to improve the Coefficient of Performance (COP) of the transcritical CO 2 refrigeration cycle. The pressure diagram as a function of the rotation angle ( p – θ diagram) was recorded by two pressure sensors arranged within the expansion chamber, based on which the features of the Working Process were analyzed and effects of the some improvement measures on the internal leakage were discussed. Compared with the ideal p – θ diagram, the recorded diagrams presented more rapid decrease in the pressure during expansion Process, which was attributed to serious leakage within the expander. Further analysis of the recorded p – θ diagrams showed that three adjacent vanes instead of two formed an integrated Working chamber, which implied that the in-between vane did not contact the cylinder wall at all, and this guess was proved by the high speed video recording of the running rotor together with the vanes during operation of the expander in CO 2 system. By arranging springs in the vane slots, tight contact between the vanes and the cylinder wall was ensured and hereby the Working Process was improved. The gap between the suction and discharge ports was another important leakage path and installation of a seal there could increase the pressure difference through the expander by 1.5–2.5 MPa by decreasing the leakage directly from the high-pressure suction chamber to the low-pressure discharge chamber. Performance test of the modified expander prototype with springs in the slots and seal at the seal arc showed that the volumetric efficiency increased from 17% to 30% and the isentropic efficiency from 9% to 23% at the speed of 800 rpm.
Ting-rong Ren - One of the best experts on this subject based on the ideXlab platform.
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New method of thermodynamic computation for a reciprocating compressor: Computer simulation of Working Process
International Journal of Mechanical Sciences, 1995Co-Authors: Si-ying Sun, Ting-rong RenAbstract:Abstract On the basis of the fundamental equations of thermodynamics, a new method proposed in this paper gives comprehensive consideration of the various factors, such as heat transfer, leakage, gas pulsation and valve motion, that influence the Working Process of the compressor and establish all the mathematical simulation equations. By using numerical computation, the thermodynamic parameters which govern the Working Process of the compressor and the macroscopic thermodynamic performances, such as capacity, power and specific power in the compressor can be found. The results of the computation are in good agreement with practical measurements and the correctness and applicability of the proposed method are demonstrated.
Derek B. Ingham - One of the best experts on this subject based on the ideXlab platform.
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Theoretical investigations on the Stirling engine Working Process
Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022), 2000Co-Authors: Kh. Kh. Makhkamov, Derek B. InghamAbstract:The use of CFD models significantly extends the capabilities for the detailed analysis of the complex heat transfer and gas dynamic Processes which occur in the internal gas circuit of a Stirling engine. In this paper, some restrictions on the implementation of a two-dimensional CFD model for the description of the Working Process of the Stirling Engine with a complex geometry for its heat exchangers are discussed. A mathematical model for a 2-dimensional simulation of a "V"-type Stirling engine is described and a simplified axis-symmetric calculation scheme for the engine has been assumed using the standard K-E turbulence model with a deforming mesh to describe the piston movements for the analysis of the engine's Working Process. Gas temperature and pressure distributions and velocity fields in the internal circuit of the engine have been obtained and pressure-volume diagrams for the Working spaces of the machine have been calculated. Comparison of the numerical results obtained from the two-dimensional simulation of the engine's Working Process with those computed with the use of second-order mathematical models shows that there are considerable differences. In particular, an analysis of the data obtained shows that the changing of the gas temperature in the compression space depends on the location in the cylinder and it may differ substantially from being harmonic in time. At present work on the experimental validation of the computational results is underway and it is planned to use the developed approach in the design Process of new Stirling engines in the Laboratory for Stirling Engines at the Physical-Technical Institute in Tashkent.
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Analysis of the Working Process and Mechanical Losses in a Stirling Engine for a Solar Power Unit
Journal of Solar Energy Engineering-transactions of The Asme, 1999Co-Authors: Kh. Kh. Makhkamov, Derek B. InghamAbstract:In this paper a second level mathematical model for the computational simulation of the Working Process of a 1-kW Stirling engine has been used and the results obtained are presented. The internal circuit of the engine in the calculation scheme was divided into five chambers, namely, the expansion space, heater, regenerator, cooler and the compression space, and the governing system of ordinary differential equations for the energy and mass conservation were solved in each chamber by Euler`s method. In addition, mechanical losses in the construction of the engine have been determined and the computational results show that the mechanical losses for this particular design of the Stirling engine may be up to 50% of the indicated power of the engine.
