Compressor Parts Research Articles

Виявлення впливу шорсткості та радіального зазору на характеристику осьового багатоступеневого компресора

The operation of gas turbine engines inevitably increases the blade roughness and tip clearance in multistage axial compressors. The result is an increase in its thermogasodynamic parameters. The reason for the increase in the roughness of the blades and the tip clearance can be various factors: clogging of the flow part of the compressor (adhesion and deposition of dust on the surface of the blades), erosion due to the arrival of hard sand grains in the flow part, etc. The subject of this study is thermogasodynamic processes in the flow part of a multistage axial compressor, based on the presence of flow part removal. The goal is to develop a methodology for forecasting and researching the influence of the blade surface roughness and increased tip clearance on the overall characteristics of a multistage axial compressor. A twelve-stage axial compressor was used as the research object. The guiding vanes of the first four stages and the inlet guiding vanes depend on the rotation frequency. As a result, it was not possible to investigate the influence of the surface roughness of the blades and the increased tip clearance on the overall characteristics of the multistage axial compressor. The calculation of the characteristics of an axial multistage compressor with simulation of different levels of roughness and increased tip clearance in comparison with its initial values and obtained several indicators of changes in thermogasodynamic parameters and characteristics of the compressor with changes in roughness (ks = 3 μm, ks = 20 μm, ks = 40 μm) was performed. and tip clearance (Δr=1%, Δr=2%, Δr=5%). The scientific and practical novelty of the obtained results arises from the following: the method of calculating the thermogasdynamic parameters and characteristics of an axial multistage compressor has been improved, which makes it possible to evaluate the effect of the roughness of the surfaces of the blades and the increased tip clearance; new data were obtained regarding the change in the compressor characteristics at different levels of roughness and the size of the tip clearance.

Research Progress on the Manufacturing of Screw-Shaped Parts in Screw Compressors

Screw compressors are highly researched and developed prospects in industry because of their long service life, high transmission efficiency, low footprint and low vibration. As the key core part of the screw compressor, the screw is a typical, long-shaft, complex profile part. Its processing method, manufacturing accuracy and quality have an extremely important impact on the performance of the whole screw compressor. In this work, the research progress on the manufacturing of screw-shaped parts in screw compressors is summarised from the aspects of the cutting process, solid plastic forming, casting and additive manufacturing. The merits and demerits of these manufacturing processes are provided and discussed, which is conducive to the development of the high-efficiency, precise and high-performance forming process of screw-shaped parts. Additionally, a novel forming process is proposed to solve the problems of serious material waste and low production efficiency for the screw-shaped parts. In the proposed process, the semi-solid spherical grain is firstly prepared by radial forging and the isothermal treatment of long-shaft raw materials. The large strain energy can be stored in the bar by the radial forging of long-shaft raw materials, which is used to induce the generation of semi-solid spherical grains with the assistance of the isothermal procedure. After that, the screw is fabricated by the high-efficiency semi-solid closed extrusion process.

Evaluasi Kinerja Turboexpander (KE -5601) Berdasarkan Kondisi Minimum Feed Di Unit 56 LPG Plant PT Perta Arun Gas

A turboexpander is an escrow and compressor connected in a process. The turboexpander rotates at high speed by utilizing gas expansion in the expander and gas compression in the compressor. The compressor-expander consists of wheels at each end that are gassed. The gas flow at high speed will rotate the shaft connected to the end of the compressor part. The purpose of this paper is to calculate the efficiency of equipment that is able to maximize the separation process between methane and ethane, and simulate flow and pressure variations to see changes in efficiency. The method used is to take the measured output value from the tool in the form of flow rate, pressure and temperature. Based on the calculation results obtained η=77%, HpExpander=2619.40 Horsepower, shaft speed=5220.76 rpm, and QLoss=22%.

Design improvement for suction shape in rotary compressor

Rotary compressors applied to heating and cooling cycles accounts for a large proportion of the total energy consumed in the system. Therefore, improving compressor efficiency is crucial in order to reduce energy consumption. Design review and improvement efforts have primarily focused on compression and discharge parts with high pressure. However, due to the limitations in design improvements for the compression and discharge parts, enhancements for other components are necessary to further increase compressor efficiency. In this study, the design of the suction part of the rotary compressor was modified using FSI (Fluid-Structure Interact) analysis scheme. In order to improve the design of the suction shape, new suction shape types were devised as alternatives to the existing through type. Both the newly devised C-type and E-type suction shapes presented an increase in cooling capacity due to reduced suction resistance, with the E-type demonstrating greater improvement compared to the C-type. Consequently, a verification of the effect based on the detailed design dimensions was further conducted for the E-type suction shape. The final selected improved model increased the suction flow rate by approximately 2.5% compared to the base model. This indicates that significant improvement for the compressor efficiency can be achieved through modifying designs in parts other than the compression and discharge sections. In addition, a design improvement process was established to analyze internal flow using FSI analysis.

Analisis Kinerja Kompressor Screw Oil Injected Sullair Ls20-150h untuk Ash Handling (Study Kasus PLTU Teluk Sirih)

PLTU Teluk Sirih is a coal-fired steam power plant as an energy source that produces ash with a capacity of 2 . The compressor is a medium for transferring ash by using compressed air. The compressor used is a SCREEW OIL INJECTED SULLAIR LS20-150H compressor. Currently there is a decrease in performance on the compressor, which initially had a compression ratio of 1,600 Psia, polytropic head 14,500,599, capacity 10,938,438, flow rate 11,379,622 lb/s, efficiency 98.5%. After analyzing this compressor, the data obtained was a compression ratio of 1,540 Psia, polytropic head 13,805,166, capacity 10,950,733, flow rate 11,392,412, and efficiency of 95.3%. The reason is because the compressor room area does not have an active blower so that dirt/ash stuck to the radiator fins causes heat transfer to be hampered and this greatly affects the performance of the compressor parts to work optimally

Учет влияния производственных отклонений от формы проточной части многоступенчатого осевого компрессора

The paper presents the results of influence for manufacturing deviations from the shape of the flow part – cavities obtained during the refinement of the material part of the multistage axial compressor GTE-65.1. An approach to the mathematical description of cavities is described, consisting of four steps. This approach allows us to gradually determine the influence of the deviation on the characteristics of the compressor. For each of the four steps the integral characteristics of the compressor deviations in efficiency and the total pressure ratio are compared to the base geometry. The change in the stability of the compressor is analyzed, taking into account the cavities under consideration. The analysis of changes in the parameters of the compressor stages is carried out.

Improving the Microstructure and Wear Behavior of Gas Turbine Compressor Parts Through the Application of FeCoNiCuAl–WC High Entropy Composite Coating by Laser Cladding

Improving the Microstructure and Wear Behavior of Gas Turbine Compressor Parts Through the Application of FeCoNiCuAl–WC High Entropy Composite Coating by Laser Cladding

An Evaluation of the Tribological Characteristics of Diaphragm Plates for High-Pressure Hydrogen Gas Compressor Applications

Diaphragm plates, a key part of high-pressure hydrogen gas compressors, are easily cracked or broken due to repeated shape deformations caused by pressure, resulting in increasing difficulties in maintenance. This study aimed to improve the durability of diaphragm plates. This investigation focuses on the potential for friction and wear reduction through the application of surface polishing and Teflon coating on two diaphragm plate materials, namely stainless steel 301 and Inconel 718. To achieve this, various metal substrates with diverse surface morphologies were prepared and subjected to comprehensive assessments of their surface, mechanical, and tribological properties. Research findings revealed that the surface hardness and tensile strength of stainless steel 301 surpassed those of Inconel 718. Through friction and wear analysis, it was observed that Teflon-coated diaphragm plate material with a microstructure demonstrated superior friction performance. Furthermore, finite element analysis was employed to investigate the stress behavior of stainless steel 301 under different applied loads and conditions, offering valuable insights into the diaphragm’s performance. From the results of this study, the excellence of the Teflon coating applied to the surface of stainless steel 301—the material of the hydrogen compressor diaphragm plate—was confirmed.

Numerical simulation and exergy analysis of a single-stage GM cryocooler

Improving the efficiency of the GM cryocoolers is of great importance for energy saving and CO2 emission reduction due to the large amount of cryocoolers installed in the emerging fields of semiconductor manufacture and High Temperature Superconductors (HTS) cooling. Previous studies mainly focused on the losses analysis and optimization on the part of cold head, but the details of losses distribution in the parts of compressor and rotary valve were seldom carried out. In this paper, a numerical model of a single stage GM cryocooler including compressor, rotary valve and expander is built, and the feasibility of the model is verified by the experimental results. The losses characteristics of the whole cryocooler are studied based on the exergy analysis method with the help of the numerical model. The results indicate that the main losses are occurred in compressor and rotary valve, the value of exergy loss in compressor decrease with the cooling temperature, and accounts for more than 60% at all cooling temperature. The loss in rotary valve accounts for about 20% of the input electric power, and it does not significantly vary at different cooling temperatures. Pressure drop dominates the loss in the compressor and rotary valve. The insufficient heat exchange between the working gas and regenerative material is the main loss in regenerator, and the losses in regenerator increase significantly with the decrease of cooling temperature when the compressor and rotary valve are fixed. This study provides useful guides for the optimization of GM-type cryocoolers.

Detection of Porosity in Impregnated Die-Cast Aluminum Alloy Piece by Metallography and Computer Tomography

The porosity of die-cast aluminum alloys is a determining factor for the quality of the product. In this paper, we studied the porosity of a selected part of a die-cast AlSi9Cu3(Fe) compressor part by computer tomography and metallography. In the case of this part, the achievable resolution by CT, a non-destructive testing method, was 30 μm—this method could not detect smaller cavities. Based on metallographic analysis, the percentage of defects larger than 30 μm ranges from 10 to 30% of the total number of defects, which represents 75–95% of the defective area (area ratio). Impregnation with methacrylate resin (used to seal cavities to prevent leakage) can be detected with UV-illuminated optical microscopic examination on metallographically prepared specimens. As confirmed by scanning electron microscopy, partial filling and partial impregnation can occur in a system of shrinkage cavities.

Influence of technological processing parameters on the accuracy of manufacturing an axial compressor disc

A technique for determining the error in processing of the end surfaces of axial compressor parts is proposed. The formation of errors is described taking into account cutting forces and tool wear. Keywords: axial compressor, cutting forces, wear, tool.nga112001@list.ru

Highly efficient centrifugal compressors series development for the turbo-cooling machines

BACKGROUND: Currently, there is a growing demand for single-stage centrifugal compressors with a high pressure ratio. Such requirements encourage the use of high-pressure stages with high circumferential speeds u2 300 m/s, which leads to increased levels of Mach number and, as a consequence, pressure losses. Work to improve the efficiency of such steps leads to a reduction in energy consumption and an increase in the cooling capacity of refrigerating machines.
 AIMS: To develop a series of ten highly efficient high-head model centrifugal compressors with the pressure ratio of c = 2.0.
 MATERIALS AND METHODS: a complex calculation technique developed by the authors is used to increase the efficiency of the stages of centrifugal compressors. The method consists of sequential execution of 4 stages: gas dynamic calculation, profiling, three-dimensional viscous calculation, multiparametric optimization.
 RESULTS: a series of the model centrifugal compressors has been designed for the following range of design mode parameters: conditional flow coefficient 0.035 Fr0.12; theoretical head coefficient t.p. =0.74; conditional Mach number 0.93Mu0.96. The estimated isentropic efficiency of the developed centrifugal compressors ranges from 77% to 84%, depending on the flow rate of the stage.
 CONCLUSIONS: a series of ten highly efficient flow parts of centrifugal compressors have been developed, which can be used in gas-dynamic projects when designing modern centrifugal compressors.

Swirl Brake Design for Improved Rotordynamic Vibration Stability Based on Computational Fluid Dynamics System Level Modeling

Abstract The accurate characterization of compressor rotordynamic coefficients during the design phase reduces the risk of subsynchronous vibration problems occurring in the field. Although rotordynamists extensively investigate discrete compressor components (such as seals and front shrouds) to tackle instability issues, integrated or system-level analysis of compressor rotordynamics is very sparse. In reality, the impeller, eye-labyrinth seal, and the front shroud heavily influence one another; and the collective dynamic behavior of the system differs from the sum of the dynamic behavior of isolated components. A computational fluid dynamics (CFD)-based approach is taken to evaluate the dynamic behavior of the system as a whole. The geometry and operating conditions in this work are based on the recent experimental study of Song et al. (2019, “Non-Axisymmetric Flows and Rotordynamic Forces in an Eccentric Shrouded Centrifugal Compressor—Part 1: Measurement,” ASME J. Eng. Gas Turbines Power, 141(11), p. 111014. 10.1115/1.4044874) on centrifugal compressor. The commercial CFD code cfx 19.0 is used to resolve Reynolds-averaged Navier–Stokes equations to quantify the eye-labyrinth seal and front cavity stiffness, damping, and added mass. The entire compressor stage is modeled to uncover the coupled behavior of the components and assess the stability of the whole system instead of just discrete components. In the current work, three CFD approaches, namely quasi-steady, transient static eccentricity, and transient mesh deformation techniques are studied and benchmarked against analytical and experimental results from the literature. Having established the efficacy of the proposed approach, four types of swirl brakes are proposed and analyzed for stability. The novel swirl brakes create negative swirls at the brake cavities and stabilize both the front shroud and the eye-labyrinth seal simultaneously.

Stress Distribution, Frequency Response, Mode Shape of Twisted and Untwisted Compressor Blisk under Different Pressure Loading Conditions

Bladed integrated disk (blisk) is a turbo engine compressor part that is specially designed to permit an adequate amount of compressed air into the burner. Blisk is used to enhance the short take-off and landing capability of the multirole fighter aircraft, because it has both rotary disc and blade. The design of the blisk needs to be carried out carefully since it is a critical part in respect of design and is subject to stringent controls. Modelling and analysis of compressor blisk diminish the complications in the design process and to enhance the quality of the design phase. In this research, finite element modelling and analysis of the compressor blisk blade is carried out to determine the stress developed in high-pressure compressor blisk for different pressure loading conditions and at three different blade orientations. Stress distributions, displacements, frequency response and mode shapes over the entire geometry of the blade were recorded under natural frequency and displayed. The stress developed on twisted compressor blisk is more than the untwisted one and it is increasing because of the increment in stress concentration areas and residual stresses. The frequency response and mode shape of twisted blades are higher and lower respectively than the untwisted blades because of the imbalanced residual stress development.

Calculation of the deflection of the blade of the disk of an axial gas pumping machine

The mechanism of occurrence of errors leading to failure of parts of compressors and pumps is investigated. A method is proposed for non-destructive control of the accuracy of manufacturing of non-rigid parts with end surfaces of revolution without reducing productivity. Keywords: compressor, non-rigid part, technological system, diagnostics. nga112001@list.ru

Numerical Prediction of Long-Term Droplet Erosion and Washing Efficiency of Axial Compressors Through the Use of a Discrete Mesh Morphing Approach

Abstract Online water washing represents an operation strategy commonly used to reduce compressor performance deterioration due to blade fouling. Since this kind of washing is applied when the machine operates close to full load conditions, injected droplets are strongly accelerated and consequently impact the rotor blades at high velocity, thus inducing undesirable phenomena like erosion. Here, we present a novel technique to study long-term water droplets erosion by also considering the geometry modification caused by droplets impacts. Two-phase unsteady numerical simulations were carried out, considering the injection of water droplets and their transport across the fluid flow in the first part of a real compressor, which is modeled in the region extending from the inlet to the rotor blades of the first stage. Simulations are performed on the whole machine to account for the asymmetric distribution of the spray injectors, the machine struts, inlet guide vanes (IGVs), and rotor blades. The k−ɛ realizable turbulence model with standard wall functions was coupled with the discrete phase model to track injected droplets motion. Droplets-wall interaction is modeled following the Stanton–Rutland approach aiming at detecting the effect of droplet impact (deposit, rebound, and splashing) depending on the impact conditions. Moreover, a semi-empirical erosion model developed by the authors was used to evaluate the erosion induced by the droplets injection. Material removal due to erosion is converted into nodal mesh displacement that is used by a secondary routine to implement the mesh morphing scheme. The mesh modification is applied at discrete steps to reduce the computational load. This technique is adopted to account for the blades geometry modification due to water droplet erosion leading to performance losses. Moreover, an estimation of the compressor operating life before maintenance operations is given and the water washing efficiency during the whole life of the machine is evaluated by means of proper indices. At the end of the simulation workflow, erosion phenomena are observed in all the compressor regions, especially in the rotor where erosion peaks are reached at the hub of the blades leading edge. The rotor blades wet surface was found to remain almost constant at around 50% during compressor water washing. Erosive phenomena were proved to evolve nonlinearly with time indicating the need to account for the geometry modification for obtaining an accurate prediction of the long-time process.

Electrochemical Hydrogen Compression: Modeling, Internal States Estimation and System Control

Hydrogen is a clean and flexible energy carrier that can be produced from diverse renewable energy sources (e.g., wind, solar and biomass) and used in a broad range of applications (e.g., transportation and power generation). Due to its high efficiency and carbon-free emission, hydrogen will play a key role in transition to Net Zero Emissions by 2050. However, for a successful hydrogen economy to develop, the compression and storage costs of hydrogen must be lowered to overcome its low volumetric energy density (i.e., 0.01079 MJ/L at STP). Currently， conventional mechanical compression accounts for the largest percentage of operating costs in hydrogen refueling stations [1].Electrochemical hydrogen compression (EHC) is an innovative non-mechanical technology that compresses hydrogen through application of voltage across membrane separators. Without the vulnerable moving parts of mechanical compressors, EHC is vibration-free, and the noise and possibility of compressor failure are reduced. Electrochemical compression is isothermal, in theory, and thus a higher efficiency is obtained than the adiabatic process of conventional mechanical compression. Consequently, EHC technology is attracting more and more attention as the hydrogen economy takes off.The proton conductivity of the proton exchange membrane (PEM) used in EHC is dependent on its water content and has a significant impact on the EHC performance. Unlike in PEM fuel cells, water is not a reaction product in EHC. Therefore, it is necessary to develop a control system to monitor the hydration degree of the membrane. Besides water management, thermal management is also important. Since high temperature can affect the stability of perfluoro-sulfonate polymers like Nafion®, their operating temperatures are typically below 353 K [2]. Reasonable optimization of operating conditions including current density, back pressure, gas flow, and inlet relative humidity, can effectively manage the temperature and moisture inside the EHC. However, the real-time internal states (e.g., temperature and water content) of EHC must be determined. Mathematical model of EHC with detailed geometries can be built to reveal the multiple coupling phenomena for mass/heat transfer, fluid flow and electrochemical reaction inside the EHC. Also, the EHC model can be used for system control and fault diagnosis.In this study, a high-fidelity dynamic model of EHC is developed with due consideration of two-dimensional distributed mass/heat transfer coupled with electrochemical kinetics. In the EHC model, the dynamics inside the anode and cathode gas channels are characterized by the discretized conservation equations of mass and energy balances, and a lumped parameter model is used to describe the transport and electrochemical reaction in the membrane electrode assembly (MEA). A numerical approach is implemented to solve the spatial derivatives of the gas channel model. Using appropriate boundary conditions, forward or backward differences are employed to realize finite-difference discretization. In the n-discretized finite elements model of EHC, the inlet and outlet flow of cathode and anode gas channels are considered as the boundary conditions. The reaction gas and water transport terms are considered as input disturbances for the discretized model, which can be determined based on the lumped MEA model.The EHC model can be used to detect local dehydration of PEM due to the unbalanced contribution of the electro-osmotic flow and the back diffusion of water across the membrane. The heterogeneities significantly affect the overall efficiency of an EHC. The physical parameters, such as the inlet relative humidity, discharge pressure, and PEM thickness, are optimized to enhance the overall efficiency of the system.[1] Parks, G., Boyd, R., Cornish, J., & Remick, R. (2014). Hydrogen station compression, storage, and dispensing technical status and costs: Systems integration (No. NREL/BK-6A10-58564). National Renewable Energy Lab. (NREL), Golden, CO (United States).[2] Sdanghi, G., Maranzana, G., Celzard, A., & Fierro, V. (2019). Review of the current technologies and performances of hydrogen compression for stationary and automotive applications. Renewable and Sustainable Energy Reviews, 102, 150-170.

Surrogate role of machine learning in motor-drive optimization for more-electric aircraft applications

Motor drives form an essential part of the electric compressors, pumps, braking and actuation systems in the More-Electric Aircraft (MEA). In this paper, the application of Machine Learning (ML) in motor-drive design and optimization process is investigated. The general idea of using ML is to train surrogate models for the optimization. This training process is based on sample data collected from detailed simulation or experiment of motor drives. However, the Surrogate Role (SR) of ML may vary for different applications. This paper first introduces the principles of ML and then proposes two SRs (direct mapping approach and correction approach) of the ML in a motor-drive optimization process. Two different cases are given for the method comparison and validation of ML SRs. The first case is using the sample data from experiments to train the ML surrogate models. For the second case, the joint-simulation data is utilized for a multi-objective motor-drive optimization problem. It is found that both surrogate roles of ML can provide a good mapping model for the cases and in the second case, three feasible design schemes of ML are proposed and validated for the two SRs. Regarding the time consumption in optimizaiton, the proposed ML models can give one motor-drive design point up to 0.044 s while it takes more than 1.5 mins for the used simulation-based models.

Study on the extraction method of the friction-induced vibration signal of rotary compressors

The operation noise level of air conditioners has been a main concern to consumers. The friction-induced vibration and noise have a contribution to the overall operation noise level of air conditioners. In this paper, two rotary compressors were tested to measure the vibration and noise of the compressors. The friction-induced vibration signals were extracted using a combination of the harmonic wavelet transform and the envelope spectrum analysis. The two rotary compressors were disassembled to check whether the compressor parts have been worn after testing. Results show that when the crankshaft was worn, the friction-induced vibration of compressors is strong. At low rotational speeds of the rotary compressor, the friction-induced vibration is easily excited, which is probably attributed to the boundary lubrication at the interface between the crankshaft and bearing. At high rotational speeds of the rotary compressor, the friction-induced vibration is not easy to be excited, which is probably attributed to the aerodynamic lubrication at the interface between the crankshaft and bearing.

Trends in tribological behaviour of materials for compressors

This review accumulates information from various research works about the preferable manufacturing process, process parameters, parts of the compressor, working principle, material, and critical issues with some of the solutions that might be possible in the era of future industry. In addition, some work is also done on the tribological trends in the compressor. In this paper, detailed information has been gathered about the compressor parts and their working principle. A detailed analysis has been done on the material used to manufacture the compressor. Some details have been shared about preventing the loss to the compressor when it is in the application mode. As per this paper, PTFE/MoS2, FC, PEEK/Ceramic materials, mica-filled tetrafluoroethylene are advanced materials used for the compressor. Protective layers can be made on the parts to prevent some functional loss. Numerous studies have brought about great advancements in compressor performance, but many remain to be discovered. With n-TiO2 and n-MnO2, ZDDP (zinc disulfide) should be increased for antifriction properties. Some research has proven that CO2 can improve the tribological performance of two interacting surfaces by forming a lubricating carbonate layer that reduces friction and wears. New lubricating oils are showing promising results, but with the gradual depletion of natural oil resources, efforts have to be made to make various oils obtained from sources other than oil reserves or petroleum. A completely oil-free compressor with no lubrication in the crankcase and no lubrication in the other components dry oil-free air supply may be accomplished by employing various oil-less compressor technologies such as scroll water-injected screw, two-stage dry screw, and so on. In the 21st century, it aims to maximize energy savings from air compressors. It is critical to operating at a compression level that matches the amount of air consumption (optimal volume) and to avoid operating at a compression level that is greater than necessary. The conclusion can be obtained that understanding for the compressor will be established, and some tribological issues will be solved with new technology and material.