A New Gas Compressor Product Development

Author(s):  
Ronald P. Porter

A high efficiency, low cost gas compressor is under development. Design has been completed and fabrication is in process. The manufacturer’s background in centrifugal compressor design and current methodology is discussed along with product definition. Assembly and test of the first unit is planned for summer 1996. The design features a single-stage overhung centrifugal compressor, variable inlet guide vanes, and dry gas seals.


Author(s):  
Ahmed Abdelwahab

The performance of the PSA (Pressure Swing Adsorption) or VPSA (Vacuum Pressure Swing Adsorption) cycle in an oxygen air separation process is significantly dependent upon the working capacity and working selectivity afforded by the adsorbent. These parameters in turn are dependent on the adsorption pressures employed in the VPSA cycle. Despite the increasing demand for increased capacity and pressure in VPSA air separation plants, they have conventionally used rotary-type positive displacement blowers as the process machinery. These blowers, while most adapted to the oscillating nature of the pressure swing cycles, have increasing high cost per capacity at higher capacities and become very inefficient as the cycle pressures are increased. A new low cost and more efficient process machinery solution is introduced through the use of a moderate speed direct coupled integrated feed and vacuum centrifugal compressor with inlet guide vanes to achieve high efficiencies during the varying operating conditions of the VPSA cycle. In this paper the fundamentals of a VPSA cycle as it applies to a centrifugal compressor operation is presented. A model of the design and predicted performance of a feed and vacuum VPSA centrifugal compressor is presented. A discussion of the proposed design in comparison to a conventional blower is presented. The model and predictions indeed show the superiority of the new design concept to the conventional process machinery equipment in terms of power savings and capacity increase. This new design however requires a feedback control system for the inlet guide vanes.



Author(s):  
Hiroshi Uchida ◽  
Mutsuo Shiraki ◽  
Akinobu Bessho ◽  
Yoichi Yagi

In Japan, a program of research and development of a 100 kW automotive ceramic gas turbine (CGT) has been carried out in the Petroleum Energy Center with active cooperation of petroleum, automobile and ceramics industries as well as other related industries. As a part of this research and development program, we have studied and developed a centrifugal compressor with variable inlet guide vanes for CGT engines. There has been a strong demand for a compressor with a high efficiency and a wide flow range. The compressor performance goals are an adiabatic efficiency of 81% and a surge margin of 8% under maximum power operating conditions. This paper describes the methods for designing impellers, diffusers and variable inlet guide vanes, and presents the results of compressor performance tests. The test results reveal that the surge margin and compressor efficiency at partial load are improved by using inlet guide vanes.



Author(s):  
Michael M. Cui

Suction elbows and inlet guide vanes (IGVs) are typical upstream components in front of first-stage impellers in centrifugal compressors. The three-dimensional distortion induced by elbows and IGVs affects the flow field behind the IGV housing. Since the flow field in front of the impeller is subsonic, the flow motion induced by the rotating impeller will interact with the elbow and IGVs as well. The flow field resulting from these interactions is three-dimensional. The nature of this flow field defines design requirements of upstream components and impact overall performance of the compressor. To understand the mechanism controlling the interactions of up-steam components and optimize the compressor design for better efficiency and reliability, a numerical simulation of the flow field inside the entire first stage of the compressor was conducted. The stage studied includes suction elbow, IGV housing with vanes, and first-stage impeller. HFC 134a was used as the working fluid. The thermodynamic and transport properties of the refrigerant gas were modeled by the Martin-Hou equation of state and power laws respectively. The three-dimensional flow field was simulated with a Navier-Stokes solver using the k-ε turbulence model. The overall performance parameters are obtained by integrating the field quantities. The force, torque, and arm of moment acting on the IGVs were then calculated. The results can be used to improve centrifugal compressor design to achieve higher efficiency and improve reliability. The methodology developed in the current study can be applied to centrifugal compressor design and optimization.



Author(s):  
Qifeng Ni ◽  
Anping Hou ◽  
Ye Tian ◽  
Quanyong Xu ◽  
Enlai Liu

A single stage centrifugal compressor has been designed for industrial use. Adjustable Inlet Guide Vanes (IGVs) and vaned diffusers were equipped to meet the requirement of large flow range, high efficiency and constant shaft speed. Both numerical calculations and experiments were implemented to get the performance of this new designed centrifugal compressor. The influence of adjustable IGVs and vaned diffusers on the stage performance characteristic was examined by numerical method. It is shown that numerical simulation results are close to the measured results and predict the stall limit well. The new centrifugal compressor has a comparatively high efficiency and wide operating range. Moreover, unilateral adjustment of either IGV pre-whirl angle or vaned diffuser stagger angle enables an increase in stable operating range opposed to the stage configuration with no adjustment. The combination of simultaneous adjustment of the IGVs and diffuser vanes can not only provide even wider flow range but also keep high efficiency. The identical working point can be operated at different IGV pre-whirl angles and diffuser stagger angles, hence the optimum adjustment schedule for the specified operating line was dug up to obtain an optimum efficiency. Detailed flow field analysis was performed to validated the suitable simultaneous adjustment combinations.



Author(s):  
Michael M. Cui

A suction elbow and inlet guide vanes (IGVs) are typical upstream components in the front of the first-stage impeller in a centrifugal compressor. Since the flow field in the front of the impeller is subsonic, the flow motion induced by the rotating impeller interacts with the elbow and IGVs. These interactions induce turbulent unsteady flows inside compressors. The resulted unsteadiness affects efficiency, vibration, and noise generation of the compressor. To understand the mechanism controlling the interactions between up-steam components and to optimize the compressor design for better efficiency and reliability, the turbulent unsteady flow inside the first-stage of the compressor was simulated. The model includes the suction elbow, inlet guide vane housing, and first-stage impeller. HFC 134a was used as the working fluid. The thermodynamic and transport properties of the refrigerant gas were modeled by the Martin-Hou equation of state and power laws, respectively. The three-dimensional unsteady flow field was numerically simulated. The overall performance parameters were obtained by integrating the field quantities. The force, torque, and the arm of moments acting on the IGVs are then calculated. The results can be used to improve centrifugal compressor design to achieve higher efficiency and improve reliability.



Author(s):  
Zilong Zhao ◽  
Zhiwei Guo ◽  
Zhongdong Qian ◽  
Qian Cheng

The axial pump operating in the pump-as-turbine mode is a practical and cost-saving alternative suitable for low-head pico hydropower in rural and remote areas that bypasses the need for expensive turbines. Their pump characteristics, however, indicate that efficiency is low in off-design flow rates. Using the computational fluid dynamics, the adjustable inlet guide vanes with five angles (±20°, 0°, ±10°) in front of the impeller of the axial pump have been redesigned and installed specifically to increase the operating range of high efficiency in the pump-as-turbine mode. To validate the simulation method, a prototype of the axial pump was built to measure in the pump mode the pump characteristics including head and efficiency. The results obtained show that the computational fluid dynamics calculated results are in qualitative agreement with the experimental data. In the pump-as-turbine mode, the adjustable inlet guide vanes were found to affect the performance of the axial pump. The most important aspect is that the adjustable inlet guide vanes widen the efficiency range if the inlet guide vane angle is adjusted for different flow rates. For the same situation with negative angles, the efficiency values at the BEP are higher than those with positive angles, where the efficiency around the angle − 10° is the highest. The main reason is that the direction of flow at the impeller-zone exit is guided by the adjustable inlet guide vanes to reduce the energy loss, which can be supported in the view of vector field and energy losses of different parts of pump.



2020 ◽  
Vol 12 (11) ◽  
pp. 168781402097490
Author(s):  
Fenghui Han ◽  
Zhe Wang ◽  
Yijun Mao ◽  
Jiajian Tan ◽  
Wenhua Li

Inlet chambers (IC) are the typical upstream component of centrifugal compressors, and inlet guide vanes in the IC have a great impact on its internal flow and aerodynamic loss, which will significantly influence the performance of the downstream compressor stages. In this paper, an experimental study was carried out on the flow characteristics inside a radial IC of an industrial centrifugal compressor, including five testing sections and 968 measuring points for two schemes with and without guide vanes. Detailed distributions of flow parameters on each section were obtained as well as the overall performance of the radial IC, and the causes of the flow loss inside the IC and the non-uniformity of flow parameters at the outlet section were investigated. Besides, numerical simulations were performed to further analyze the flow characteristics inside the radial IC. The experimental and numerical results indicate that, in the scheme without guide vanes, sudden expansions in the spiral channel and flow separations in the annular convergence channel are the major sources of flow loss and distortions generated in the radial IC; while in the scheme with guide vanes, the flow impacts, separations and wakes caused by the inappropriate design of guide vanes are the main reasons for the flow loss of the IC itself and the uneven flow distributions at the IC outlet.



1991 ◽  
Vol 113 (4) ◽  
pp. 696-702 ◽  
Author(s):  
C. Rodgers

This paper describes the results of compressor rig testing with a moderately high specific speed, high inducer Mack number, single-stage centrifugal compressor, with a vaned diffuser, and adjustable inlet guide vanes (IGVs). The results showed that the high-speed surge margin was considerably extended by the regulation of the IGVs, even though the vaned diffuser was apparently operating stalled. Simplified one-dimensional analysis of the impeller and diffuser performances indicated that at inducer tip Mach numbers approaching and exceeding unity, the high-speed surge line was triggered by inducer stall. Also, IGV regulation increased impeller stability. This permitted the diffuser to operate stalled, providing the net compression system stability remained on a negative slope.



2017 ◽  
Author(s):  
Michele Becciani ◽  
Alessandro Bianchini ◽  
Matteo Checcucci ◽  
Lorenzo Ferrari ◽  
Michele De Luca ◽  
...  


Sign in / Sign up

Export Citation Format

Share Document