Browse Topic: Compressors

Items (1,095)
ABSTRACT Additive/Abradable Powder Coatings (AAPC’s) are field proven, thick, solid film graphite coatings that wear in to the ideal functional geometry of mechanical components. Lubed or dry, devices lap in and run with minimized clearance and friction for highest efficiency, quietest operation, and longest life in sandy environments. AAPC’s will improve military readiness, reduce sustainment costs, and cut components logistics and fuel consumption. Processing is easy, robust and effective on new and used components in prototyping, production and remanufacturing. Worn components can be restored in theater to achieve durable, ‘better than new’ performance levels. Applications include turbos, IC pistons, lube pumps, hydraulics, roots blowers, screw compressors, refrigerant compressors, lip seal seats, and others. This paper will focus on the AAPC benefits observed on pistons and turbo compressor housings
Suman, Andrew
Air suspension systems are increasingly in demand in high-end cars due to their ability to vary ride height based on vehicle loads, road conditions, and speeds. This trend has driven manufacturers to enhance the performance of these systems. Predicting and optimizing the performance of the air spring system for various vehicle loads and conditions has become essential. The performance of an air suspension system is typically measured by its ability to suspend the vehicle within a specified target time. Therefore, it is necessary to model the air spring system—including the air spring, compressor, pneumatic lines, and valves—and integrate it with the vehicle. This modeling helps in predicting performance and optimizing the system. Additionally, a validated system model enables other important calculations, such as sizing the valves, pneumatic hoses, and compressors. In this study, a complete air spring system model has been developed alongside a 15-degrees-of-freedom car chassis to
Ahmed, Saad AnwarHupfeld, JanRajput, Brijesh
Leak Before Break (LBB) is now widely applied in pressure vessels and other pressurized components to detect the failure by unstable crack initiation and propagation. This concept is also applied in pneumatic brake system components to validate the structural rigidity of the devices. Pneumatic brake system component plays a vital role in the commercial vehicle platform. It consists of four major systems such as charging systems, actuating systems, control systems and actuators. Charging System includes compressor, reservoir, air dryer, and system protection valves. Compressor acts as an energy source for pneumatic air brake systems, reservoir is used to store the compressed air generated by the compressor, and system protection valves are used to divide and distribute the air flow to the brake system. Air dryers are used to absorb moisture, oil particles and tiny foreign contaminants, regulate the system pressure, and blow off the excess pressure from the system. It contains a
Govindarasu, AnbarasuT, SukumarSubramanian, Vivek
With the advent of electric and hybrid drivetrain in the commercial vehicle industry, electrically driven reciprocating compressors have gained widespread prominence. This compressor provides compressed air for key vehicle systems such as brakes, suspension systems and other auxiliary applications. To be a market leader, such an E-compressor needs to meet a myriad of design requirements. This includes meeting the performance by supplying air at required pressure and flow rate, durability requirements and having a compact design while maintaining cost competitiveness. The reed valve in such a compressor is a vital component, whose design is critical to meet the aforementioned requirements. The reed valves design has several key parameters such as the stiffness, natural frequency, equivalent mass, and lift distance which must be optimized. This reed valve also needs to open and close rapidly in response to the compressor operating speed. Since it is the order of milliseconds, the valve
J, BharadwajT, SukumarPendyala, Vamsi KrishnaPaul Pandian, Adheenthran
Most of the heavy commercial vehicles are installed with Pneumatic brake system where the medium is a pressurized pneumatic air generated with the reciprocating air compressor. Heating is an undesirable effect of the compression process during loading cycles as reciprocating air compressors are concerned. Therefore it is necessary to reduce the delivery air temperature of compressor for safer operation of downstream products. The present investigation deals with the measurement of the delivery air temperature of a typical 318 cc water cooled compressor. A through steady state conjugate heat transfer analysis is conducted for the given speed and with the specification cooling water flow rate to predict the delivery air temperature. Pressure drop across the cooling water flow path has been measured and optimum flow rate is arrived to meet the design requirement. The results of characteristic analysis and comparative research show that the cooling system can obviously reduce the cylinder
N, PrabhakarV A, Sahaya IrudayarajRaj, AmalT, Sukumar
In automotive air conditioning systems, compressor is used to convert low pressure low temperature refrigerant into high pressure high temperature refrigerant. Various types of compressors like swash plate, rotary vane, scroll etc. are widely used in the automotive industry for air conditioning applications. In rotary vane compressors, thermal protector is used as a safety device, designed to prevent the compressor from overheating during refrigerant compression process. When the discharge temperature exceeds the preset limit of thermal protector, the thermal protector will activate and stop the electrical supply to compressor clutch to stop the compressor operation thereby preventing potential damage to air conditioning system, engine, and other nearby parts of the vehicle. This technical paper explores the various real-world scenarios for a hot country like India, which may result into higher discharge temperatures of compressor resulting into activation of thermal protector. The
Mittal, SachinSaha, AniketKumar, MukeshUmbarkar, Shriganesh
In electrified vehicles, auxiliary units can be a dominant source of noise, one of which is the refrigerant scroll compressor. Compared to vehicles with combustion engines, e-vehicles require larger refrigerant compressors, as in addition to the interior, also the battery and the electric motors have to be cooled. Currently, scroll compressors are widely used in the automotive industry, which generate one pressure pulse per revolution due to their discontinuous compression principle. This results in speed-dependent pressure fluctuations as well as higher-harmonic pulsations that arise from reflections. These fluctuations spread through the refrigeration cycle and cause the vibration excitation of refrigerant lines and heat exchangers. The sound transmission path in the air conditioning heat exchanger integrated in the dashboard is particularly critical. Various silencer configurations can be used to dampen these pulsations. This paper compares the acoustic and thermodynamic performance
Saur, LukasHeidegger, PatrickNaeger, ChristophBecker, Stefan
The structure-, fluid- and air-borne excitation generated by heating, ventilation and air conditioning (HVAC) compressors can lead to annoying noise and low frequency vibrations in the passenger compartment. These noise and vibration phenomena are of great interest to ensure a high passenger comfort of electric vehicles (EV). This publication describes the development of a numerical finite element (FE) model of the HVAC system and the simulation results of structure-borne sound transmission from the compressor via the HVAC hoses to the vehicle body in a frequency range up to 1 kHz. The simulation results were validated with measurements. An existing automotive HVAC system was fully replicated in the laboratory. Vibration levels were measured on the compressor and on the car body side of the hoses under different operational conditions. Additional measurements were carried out using external excitation of the compressor in order to distinguish between structure- and fluid-borne
Buchegger, BlasiusSonnberger, PiusBöhler, ElmarNijman, EugeneRejlek, JanBillermann, RobertKrüger, Yannik
In electrified vehicles, auxiliary units can be a dominant source of noise, one of which is the refrigerant scroll compressor. Compared to vehicles with combustion engines, e-vehicles require larger refrigerant compressors, as in addition to the interior, the battery and the electric motors must be cooled. The compressor causes the acoustic excitation of other refrigeration circuit components and the chassis via pressure pulsations and vibration transmission, as well as emitting airborne sound directly. Sound measurements have been performed in an anechoic chamber to investigate the influence of operating conditions on the acoustics of an electric scroll compressor. This paper investigates the influence of the operating conditions on compressor acoustics and shows that rotation speed is the main factor influencing compressor noise. The sound spectra of fluid, structure and airborne noise are dominated by speed-dependent, tonal components. Additionally the effect of varying pressure
Saur, LukasBecker, Stefan
The development of electric commercial vehicles brought up novel challenges in the design of efficient and reliable air brake systems. The compressor is one of the critical components of the air brake system and is responsible for supplying pressurized air to the brake system. In this study, we aimed to gather essential information regarding the pressure and flow rate requirements for the compressor in the air brake system of electric commercial vehicles. We extensively analyzed the existing air brake systems utilized in conventional commercial vehicles. We examined the performance characteristics of reciprocating compressors traditionally employed in these systems. Recognizing the need for novel compressor designs tailored to electric commercial vehicles, we focused on identifying the specifics such as efficiency, performance characteristics, reliability, and cost of the compressor. Our study utilized theoretical calculations to ascertain the optimal pressure and flow rate parameters
Dhere, SiddhantGupta, SuryakantKumar, G. C. MohanReddy, Vamsikrishna
In the present work, a new methodology for predicting the performance of centrifugal compressors is developed. The proposed method differs from existing methods found in literature by gathering principal losses in three parameters: two constants and one variable, which is a function of the compressor wheel geometrical characteristics. As those parameters are constants for a given centrifugal compressor, there is no need for additional corrective parameters in order to obtain coherent results. Indeed, the proposed methodology does not depend on the choice of the slip factor correlation for the prediction of the correct pressure ratio. However, the choice of slip factor influences the efficiency computation. The prediction of the compressor maps for two full stage centrifugal compressors is presented and they show good agreement while compared with manufacturer’s data obtained from gas stand measurements. In addition, a method to obtain the surge line based on this methodology is
Martinez Alvarado, Luis EnriqueMilosavljevic, Misa
In recent years, with the development of computing infrastructure and methods, the potential of numerical methods to reasonably predict aerodynamic noise in turbocharger compressors of heavy-duty diesel engines has increased. However, aerodynamic acoustic modeling of complex geometries and flow systems is currently immature, mainly due to the greater challenges in accurately characterizing turbulent viscous flows. Therefore, recent advances in aerodynamic noise calculations for automotive turbocharger compressors were reviewed and a quantitative study of the effects for turbulence models (Shear-Stress Transport (SST) and Detached Eddy Simulation (DES)) and time-steps (2° and 4°) in numerical simulations on the performance and acoustic prediction of a compressor under various conditions were investigated. The results showed that for the compressor performance, the turbulence models and time-step parameters selection were within 3% error of the simulated and experimental values for
Huang, RongNi, JiminWang, QiweiYin, Qi
The inverter of the electrical driven compressor (EDC) is subjected to high thermal loads which are resulting from external temperature exposure and from compressor solicitations from the vehicle thermal loop (refrigerant nature, flow rate, compression rate, initial temperature). An incorrect thermal management of the inverter might lead to a significant decrease of efficiency which degrades the performance, product lifetime (electronics components failure) and even worse, might lead to a hazardous thermal event (HTE). The need of the automotive market to drastically decrease project development time, requires decreasing design and simulation activities lead time without degrading the design robustness, which is one additional complexity and challenge for the R&D team. Analytical calculations are performed to understand the significant impact of the main physical parameters (refrigerant temperature, material properties, electronics component power dissipation, …) on the initial design
Banumurthy, HariharanRibot, HerveLeon, RenanFrancois, NicolasSattouf, MousaMarouf, Ayyoub
Customers expect more advanced features and comfort in electric vehicles. It is challenging for NVH engineers to reduce the vibration levels to a great extent in the vehicle without adding cost and weight. This paper focuses on reducing the tactile vibration in electric vehicle when AC is switched ON. Vibration levels were not acceptable and modulating in nature on the test vehicle. Electric compressor is used for cabin cooling and battery cooling in the vehicle. Compressor is connected to body with the help of isolators. Depending upon cooling load, the compressor operates between 1000 rpm and 8000 rpm. The 1st order vibration of compressor was dominant on tactile locations at all the compressor speeds. Vibration levels on steering wheel were improved by 10 dB on reducing the dynamic stiffness of isolators. To reduce the transfer of compressor vibration further, isolators are provided on HVAC line connection on body and mufflers are provided in suction and discharge line. With the
S, Nataraja MoorthyRao, ManchiRaghavendran, PrasathManivannan, Giridharan
For ensuring environmental safety, strong emphasis on CO2 pollution reduction is mandated which led to evolution of miller cycle engines. However, the inherent Miller engine characteristic is the lower volumetric efficiency when compared to otto engines because of which small turbo chargers with variable geometry turbines are used to induct air into the engine. With miller engine and VGT turbo charger combination arises the challenges of charge controllability because of lower inertia and reduced vane control area. With conventional turbo charger control methods, the response time is slow thereby leading to turbo lag or severe over boosting, this is overcome by accurate engine modelling and using the same as input for charger control. In this study, model-based calibration approach was performed on a 3-cylinder Miller GDI 1.2L engine to model the charge exchange of the engine and use the same for determination required turbine vane positions to achieve the desired airflow induction
Veeramani, VivekanandKarthi, RamanathanShanmugam Ramakrishnan, Muthu
This SAE Recommended Practice is intended to describe a procedure for rating the size of single-stage reciprocating air compressors. It describes the conditions that can be used for testing and it defines a standardized rating expressed in SLPM (SCFM
Truck and Bus Brake Supply and Control Components Committee
Scroll compressors are commonly used in HVAC and thermal management systems of electric and hybrid vehicles because of its high operating efficiency and smooth operation. The compressor is driven by an electric motor which forms a coupled system called an e-compressor unit. The refrigerant cools the motor before entering the scroll compressor. At different operating conditions of the vehicle, the change in power of the motor alters the refrigerant temperature and hence affecting the compressor’s performance. In the present work, 3D Conjugate Heat Transfer simulation of an e-compressor is performed as a complete unit with flow and heat transfer through the motor and compressor. A novel mixed timescale approach for the heat transfer has been developed to simulate the effect of thermal loads on the performance of the compressor. These performance parameters include the outlet temperature, volumetric efficiency, and discharge flow rate of the compressor. The motion of reed valve at the
Ballani, AbhishekPasunurthi, Shyam SundarSrinivasan, ChiranthMaiti, Dipak
Compressor plays an important role in Automotive Air Conditioning (AC) System. It compresses the low pressure refrigerant and discharges the high pressure refrigerant vapour to condenser. Compressor performance mainly depends on two parameters, compressor oil and refrigerant gas charge quantity. Compressor oil is used to lubricate the movable parts in reciprocating compressors. Compressor oil is miscible in refrigerants in liquid state and amount of oil present in compressor increases the life of compressor. But, huge amount of oil may also reduce the thermal performance of system. Minimum gas quantity gives poor cooling performance and due to maximum quantity, increasing suction/discharge pressures, results in more compressor work and low cooling. This paper discusses the experimental analysis of refrigerant quantity, oil quantity in different ratios to improving the cooling performance of a passenger vehicle. Experimentation was conducted on 7 seater passenger car (hatchback). For
Meena, Avadhesh KumarKishore, KamalAgarwal, RoopakParayil, Paulson
In the modern era of automotive industry, occupant comfort inside the cabin is a basic need and no more a luxury feature. With increase in number of vehicles, the expectations from customers are also changing. One of the major expectations from real world customers is quick cabin cooling thru all seasons, particularly when the vehicle is hot soaked and being used in summer conditions. Occupant thermal comfort inside the vehicle cabin is provisioned by a mobile air conditioning (MAC) system, which operates on a vapor compression-based cycle using a refrigerant. The main components of a direct expansion (DX) based MAC system are, a compressor, condenser, evaporator, and expansion valve. Conditioned air is circulated inside the cabin using a blower, duct system and air vents. The AC condenser is the most critical component in AC circuit as it rejects heat, thereby providing for a cooling effect inside the cabin. Right sizing and packaging of condenser, optimizing the condenser core
Shukla, Ankit KumarTadigadapa, SureshDimble, Nilesh
Air-conditioning and Refrigeration systems are widely used in many industries for cooling and preservation, and the evaporator is a crucial component responsible for heat absorption. The choice of refrigerant has a significant impact on the evaporator's performance, affecting the overall efficiency of the system. This paper investigates the effect of three common refrigerants, R134a, R407c, and R1234yf, on evaporator performance. A comparative analysis was performed using the conventional air-conditioning system consisting of a compressor, condenser, expansion valve, and evaporator. The evaporator performance was evaluated based on the cooling capacity, Refrigerant Side Pressure Drop (RSPD) and Superheat (SH). The results show that evaporator has highest cooling capacity with R134a, followed by R407C and R1234yf. In comparison to R134a, R1234yf had the lowest refrigerating effect followed by R407C. However, R1234yf has the lowest Global Warming Potential (GWP) value out of all the
Suman, SaurabhKushwah, Yogendra Singh
The isentropic efficiency estimation of small radial turbines is an important aspect of turbocharger performance evaluation. Because of inaccuracies in measuring the outlet temperature due to the non-homogeneous flow field distribution, it is common practice to refer to the thermomechanical efficiency, defined as the product of mechanical and turbine isentropic efficiencies. This paper proposes a method for the indirect evaluation of turbine isentropic efficiency through specific experimental tests. In particular, the evaluation of friction losses in the bearings can be assessed thanks to experimental investigations in quasi-adiabatic condition. By maintaining the turbine inlet temperature and the average temperature of lubricating oil and water-cooling circuit equal to the compressor outlet temperature, a negligible heat transfer between turbine and compressor can be achieved. Therefore, the heat transferred to the lubricating oil can only be attributed to the friction in the bearings
Cordalonga, CarlaMarelli, SilviaUsai, VittorioCapobianco, Massimo
The supplier is committed to all facets of the H2 economy as volume production of its power module kicks off for Nikola's Class 8 fuel-cell truck. At its oldest and largest location - a site long accustomed to manufacturing parts for combustion engines - Bosch is now producing what it calls the most complex system it has ever developed: a fuel-cell power module (FCPM). Production at the Stuttgart-Feuerbach site in Germany officially kicked off in July during a Bosch Tech Day event attended by global media. The pilot customer for the FCPMs is Nikola with its Tre hydrogen fuel-cell electric truck, which is expected to launch in North America in the third quarter of 2023. Bosch is committed to all facets of the hydrogen value chain, from developing an electrolysis stack and components for electrolyzers for H2 production, to engineering a drive solution for hydrogen compressors in filling stations. The supplier plans to invest nearly $2.6 billion between 2021 to 2026 in the development and
Gehm, Ryan
Since the introduction of ice crystal icing certification requirements [1], icing facilities have played an important role in demonstrating compliance of aircraft air data probes, engine probes, and increasingly, of turbine engines. Most sea level engine icing facilities use the freezing-out of a water spray to simulate ice crystal icing conditions encountered at altitude by an aircraft in flight. However, there are notable differences in the ice particles created by freeze-out versus those observed at altitude [2, 3, 4]. Freeze-out crystals are generally spherical as compared to altitude crystals which have variable crystalline shapes. Additionally, freeze-out particles may not completely freeze in their centres, creating a combination of super-cooled liquid and ice impacting engine hardware. An alternative method for generating ice crystals in a test facility is the grinding of ice blocks or cubes to create irregular shaped crystals. These grind-out particles have a different
Neuteboom, MartinFleurent-Wilson, EricChalmers, Jennifer
In 2021 the Federal Aviation Administration in collaboration with the National Research Council of Canada performed research on altitude ice crystal icing of aircraft engines using the modular compressor rig, ICE-MACR, in an altitude wind tunnel. The aim of the research campaign was to address research needs related to ice crystal icing of aircraft engines outlined in FAA publication Engine Ice Crystal Icing Technology Plan with Research Needs. This paper reports the findings on ice accretion from a configuration of ICE-MACR with two compression stages. Inherent in two-stage operation is not just additional fracturing and heating by the second stage but also higher axial velocity and potentially greater centrifuging of particles. These factors influence the accretion behavior in the test article compared to single stage accretion. The melt ratio (liquid/total water content) has been shown to be an important parameter in ice crystal icing, with a relatively narrow band of melt ratios
Mason, JeanneNeuteboom, MartinChalmers, JenniferDumont, ChristopherChow, Philip
Current modelling capability for engine icing accretion prediction is still limited for App. C. To further validate icing codes in complex engine geometries, it is necessary to perform additional experimental work in relevant geometrical and environmental conditions. Within the frame of ICE GENESIS [1], an experiment has been setup to replicate the condition at the inlet of an engine first stage compressor. This paper describes the choices for the design of the engine compressor model, the setup within the icing wind tunnel and the methodology employed to obtain the results. Additionally, more effort has been focused on obtaining accurate ice shapes using a 3D scanning system. Results of 3D scans are given
Pervier, HugoVénuat, ClémentNeubauer, Thomas
This SAE Recommended Practice establishes uniform Installation Parameters for desiccant Air Dryers for vehicles with compressed air systems
Truck and Bus Brake Supply and Control Components Committee
Conventional silencers have extensively been used to attenuate airborne pressure pulsations in the breathing system of internal combustion engines, typically at low frequencies as dictated by the crankshaft speed. With the introduction of turbocharger compressors, however, particularly those with the ported shroud recirculating casing treatment, high-frequency tones on the order of 10 kHz have become a significant contributor to noise in the induction system. The elevated frequencies promote multi-dimensional wave propagation, rendering traditional silencing design methods invalid, as well as the standard techniques to assess silencer performance. The present study features a novel high-frequency silencer designed to target blade-pass frequency (BPF) noise at the inlet of turbocharger compressors. The concept uses an acoustic straightener to promote planar wave propagation across arrays of quarter-wave resonators, achieving a broadband attenuation. The effectiveness of the silencer is
Sriganesh, PranavSelamet, Ahmet
The testing techniques outlined in this SAE Recommended Practice were developed as part of an overall program tor testing and evaluating fuel consumption of heavy duty trucks and buses. The technique outlined in this document provides a general description of the type of equipment and facility which is necessary to determine the power consumption of these engine-driven components. It is recommended that the specific operating conditions suggested throughout the test be carefully reviewed on the basis of actual data obtained on the specific vehicle operation. If specific vehicle application is not known, see SAE J1343
Truck and Bus Aerodynamics and Fuel Economy Committee
Electric centrifugal air compressor is one of the most important auxiliary components for the fuel cell engine, which has great impacts on the system efficiency, cost and compactness. However, the centrifugal compressor works at an ultra-high speed for a long time, which poses a great challenge to the lives of motor, bearing and seal. Therefore, reducing the rotating speed of the impeller and maintaining high pressure ratio and high efficiency are important issues for aerodynamic design of the compressor. In this paper, a centrifugal compressor rotor for a 100kW fuel cell system is designed. Aiming at reducing the rotating speed, the influences of three key structural parameters including inlet blade angle, outlet blade angle and blade outlet radius on performance are investigated. The aerodynamic performance of the compressor is predicted using the Reynolds-averaged Navier-Stokes (RANS) equations with computational fluid dynamic (CFD) tools. The numerical simulation and experiment
mao, HaoyuZhao, RongchaoHang, ChaodongXu, Sichuan
In automotive air conditioning systems, the oil circulation rate (OCR) is known to affect performance at both the component and system levels. The OCR is the ratio of the mass of the oil in a representative sample of oil-refrigerant mixture from the system to the total mass of the sample taken during steady state operation. With the general industry trend towards low-OCR compressors, the OCR values of interest are getting smaller, and it is becoming increasingly important to acquire an accurate knowledge of OCR for proper system optimization. While there are different OCR measurement techniques available, they all require accurate calibration which is done using the ASHRAE Standard 41.4. The standard describes a sampling technique using an evacuated sampling cylinder with a dead end to draw a sample of oil-refrigerant mixture from the system liquid line. The standard, however, doesn’t specify parameters such as sampling cylinder orientation, valve opening speed, etc. which can
Haider, Syed AngkanWang, XinElbel, Stefan
In the present paper the environmental impact of a gas-steam combined cycle, in terms of CO2 emissions has been supplemented with the energetic analysis of the cycle. The gas turbine based triple-pressure reheat combined cycle incorporates, vapor compression inlet air cooling and air-film turbine blade cooling, to study the improvement in plant performance and sustainability. A parametric study of the effect of compressor pressure ratio (rp,c), compressor inlet temperature (CIT), turbine inlet temperature (TIT), inlet temperature ratio (rIT), ambient relative humidity and ambient temperature on performance and sustainability has been carried out. The integration of inlet air cooling and gas turbine blade cooling results in a significant reduction in CO2 emission per unit plant output. The integration of vapor compression inlet air cooling to gas turbine based combined cycle, has been observed to improve the specific work by more than 10 %. The plant efficiency increases significantly
Sahu, SabyasachiThatoi, DhirendranathMohapatra, Alok
Intake system is an important noise source for commercial vehicles, which has a significant impact on their NVH performance. To predict the intake noise more accurately, a new one-dimensional prediction model is proposed in this paper. An air compressor model is introduced into the traditional model, and the acoustic properties of the intake system are simulated by GT-power. The simulation data of the inlet noise is obtained to make a comparison with the inlet noise data acquired from a test. The result shows that the proposed model can make a more precise prediction of the inlet noise. Compared with the traditional model, the proposed model can identify the noise coming from the air compressor, and achieve a more accurate prediction of the total sound pressure level of the inlet noise
Zhao, YongnanCai, YaoyuZhou, ZhengdaoXu, ZhichengChen, Shuming
Contribution to carbon neutrality is one of the most important challenges for the automotive industry. Though CO2 emission has been reduced through electrification, internal combustion engines equipped in vehicles such as Hybrid Electric Vehicle (HEV) and Plug-in Hybrid Electric Vehicle (PHEV) are still necessary for the foreseeable future, and continuous efforts to improve fuel economy are demanded. To improve powertrain thermal efficiency, direct-injection turbocharged gasoline engines have been widely utilized in recent years. Super lean-burn combustion engine has been being researched as the next generation of turbocharged gasoline engines. It is known that an increase of the boost pressure causes deposit formation, which decrease the turbocharger efficiency, in the turbocharger compressor housing. To avoid the efficiency loss due to deposit, air temperature at compressor outlet has to be limited low. In this paper, the methodology was constructed to predict compressor efficiency
Ura, HarutoKuma, HiroshiHirano, SatoshiIshizaki, Noriya
Oil migration has a great impact on vapor compression systems, especially for automobile air conditioning systems which require frequent on-off cycling without sufficient oil management inside the compressor. Excessive amounts of oil retained in the system and lack of oil returned to the compressor can cause low system efficiency and potential compressor failure. This paper explores and quantifies the transient effects in oil migration and property changes at the compressor suction and the discharge. Oil flow behavior and oil migration are quantified and analyzed by the high-speed camera recording and optical method at the compressor discharge and the liquid line under different compressor startup speeds and on-off frequencies. The flow under cold and warm startup conditions is studied and compared. The oil-refrigerant mixture flow at the suction and discharge during cold startup transitions from two-phase flow to vapor refrigerant flow and oil annular mist flow. Severe oil foaming
Wang, XinHaider, Syed AngkanElbel, Stefan
Taking a closed airbag suspension system as studying objects, the nonlinear dynamic model of the reservoir, compressor, solenoid valve, pipeline and air spring is established. The compressor exhaust volume, solenoid valve flow rate and air spring charging and discharging rate are calculated and compared with experiment to validate the model. Taking pressure difference and height adjustment rate under different working conditions of an airbag suspension as control measures, a control strategy is developed based on the established nonlinear dynamic model. The result indicates that when the vehicle is in curb weight, design weight and GVW (gross vehicle weight), the working time of the compressor can be reduced by 13.6%, 15.1% and 46.5%, respectively, compared with the conventional mode, during a height adjustment cycle. Then a state observer is proposed to estimate the steady-height for reducing the disturbance of measured height from road excitation. According to the required height
Deng, LinLv, HuiShangguan, Wenbin
In this study, a statistical correlation was established among the input parameters, namely, ambient temperature (AT), oil injection orifice (OIO) size, and cooling fan speed with free air delivery (FAD), input power (IP), and discharge oil temperature (DOT) of an electric-powered twin screw air compressor. Experiments were designed based on a central composite design (CCD). A response optimizer is used to identify the combination of input operating parameter settings that optimizes responses independently and collectively. A model considering all responses together with equal priorities provides the maximum FAD of 254.71 cfm and minimum IP of 44.16 kW by setting the compressor with an AT of 44°C, OIO size of 4.0 mm, and a cooling fan speed of 1220 rpm. Higher ambient conditions are achieved for experimental purposes by designing a hot chamber wherein hot air from the cooling fan exhaust is mixed with the ambient air. Confirmatory tests are conducted to validate the statistical model
Rameshkumar, K.Rajesh, M.Sundaranathan, R.Sumesh, A.
Air Supply Unit (ASU) serves as the pneumatic source for the air suspension system in the passenger car segment. The ASU is an electrically driven oil-free compressor with integrated air dryer to deliver dry air to the suspension system. Solenoid valve, Height Sensor and ECU adjusts the pressure in bellow based on the vehicle load condition. During the lab test, pressure was not building up in the compressor due to delivery valve failure. The type of valve in asu is reed valve type, it is mostly used in the micro compressors due to its low cost, simple structure and light weight configuration. The reed movement is based on the pressure difference between the inlet and the compression chamber. Failure analysis is carried out based on the finite element analysis to identify the root cause, the root cause identified is optimized to prevent the failure. An accelerated test condition is arrived based on the FEA and a tailored series of accelerated tests are carried out to reproduce the
Subramanian, VivekT, Dr. SukumarGovindarasu, Anbarasu
In conventional turbojet engine the turbine power is being utilized to rotate the compressors whereas in the Hybrid air breathing propulsion system, an electric motor will be used to give power input to rotate the compressor. So, the space available without a turbine could be used to accommodate a contra-rotating compressor where alternative blade rows rotate in a counter direction. Previous studies show the contra-rotating compressors are superior to conventional ones. The objective of the present work is to design a contra-rotating compressor and to numerically analyse the effects of rotational speed of rotors and inlet Mach number on the performance of the same. Numerical simulations are performed for different rotational speed values of rotors ranging from 5000 RPM to 15000 RPM and with four inlet Mach numbers starting from 0.5 to 0.8. It is found that the pressure ratio of the compressor increases with the rotational speed of the rotors and the increment is more pronounced when
Senthilkumar, SundararajJambulingam, SanjayJambulingam, Bharanitharan
Less weight, structural integrity, good dynamic behavior, material selection, performance & energy consumption are important parameters while designing A/C components for EV applications. Structural integrity and dynamic behavior of these components is predicted by conducting dynamic analysis of A/C unit under standard vibration load test conditions. Material selection is another important point while designing A/C and simulation helps designer for proper material selection at initial design stage. Achieving required cooling capacity with less compressor power is another important factor while designing A/C unit and this is done by proper design changes on condenser and evaporator side with proper compressor selection. For this, CFD analysis helps to predict the air flow accurately with the given design parameters. In this paper, information about both CAE & CFD analysis performed effectively for improvement of unit is provided.CAE analysis is performed to check strength of unit as per
Parayil, PaulsonGoel, ArunkumarSingh, Shobit KumarSen, Somnath
The aim of this paper is to establish the optimized control of external variable displacement compressor (EVDC) for the automotive air conditioning (AC) system in various operating modes. The control logic was developed, calibrated and experimentally verified on test vehicle. The developed control strategy ensures the stability of AC system while achieving the desired climate control and yielding the maximum possible fuel economy. The influence of cooling load, compressor speed and icing of evaporator have been investigated theoretically and validated with test data. The proposed control strategy ensures the safety of compressor and stabilizes the AC system under high engine torque demand, cold start conditions, engine shutdown or under electrical failures reported by on board diagnostics services (OBD). The results reveal improved thermal comfort and improvement in fuel economy with the use of established baseline control logic presented in the paper
Yadav, Aditya PratapShukla, AnkitGoel, Arun KumarSharma, Kamal
It is a known fact that the existing compressor stations on the sorting humps of the railways have significant overconsumption of electricity. First, this is due to the lack of automatic regulation of the compressed air capacity, which takes into account the technological processes at the station and the weather conditions within this section. In order to solve this problem, as a first approximation, it is necessary to analyze all the factors affecting the energy consumption of the compressor station and develop a mathematical model, which will link these indicators. In this work, a correlation analysis of the weather-related factors and specifics of the technological process (breaking up of the train), which affect the energy consumption of the compressor unit (CU), is carried out. Based on the analysis, there was a strong correlation between the factors described and the power consumption at the station. A regression model was developed. The issue of the distribution of energy levels
Volodarets, MykytaSatsiuk, AleksandrGritsuk, IgorLitikova, OleksandraAhieiev, MaksymBelousov, EvgenPohorletskyi, DmytroTkachuk, KaterynaNosov, PavloSumtsov, Andrii
The use of turbochargers with downsized internal combustion engines improves road vehicles’ energy efficiency but introduces additional sound sources of strong acoustic annoyance on the turbocharger’s compressor side. In the present study, direct noise computations (DNC) are carried out on a passenger vehicle turbocharger compressor. The work focuses on assessing the influence of grid parameters on the acoustic predictions, to further advance the maturity of the acoustic modelling of such machines with complex three-dimensional features. The effect of the boundary layer mesh structure, and of the spatial resolution of the mesh, on the simulated acoustic signatures is investigated on detached eddy simulations (DES). Refinements in the core mesh are applied in areas of major acoustic production, to generate cells with sizes proportional to the local Taylor microscale values. Such an educated guess allows for quality enhancement with a smaller increase in computational costs as compared
Pietroniro, Asuka GabrieleTrigell, EmelieJacob, StefanMihaescu, MihaiAbom, MatsKnutsson, Magnus
This work is aimed at conducting a computational study to find out the effect of vaneless space downstream of the Diffuser vane trailing edge, by varying the height of diffuser vane viz. 50%, 75%, and 100% diffuser height, on centrifugal stage performance. The considered centrifugal compressor stage in this study is NASA CC3 4:1 centrifugal stage. In all the cases diffuser leading-edge radius is the same. The compressor performance with full diffuser vane configuration (100% diffuser height) is computed and initially compared with test data. The diffuser vane height is then reduced to 50% and 75% of the original length from the diffuser leading edge. Hence, the diffuser leading-edge location remains the same as the original 100% diffuser vane height geometry whereas the location of the trailing edge changes according to vane height. Another part of the study is to model the 75% & 100% diffuser vane height with hub and shroud gaps respectively. The computational study is carried out
Kumar, ShaileshChougule, HashamAbdullah, QizarGoswami, Shraman
In commercial vehicles, compressed air is used as an energy source for the air brake system. A compressor driven by engine is used to compress and store air in reservoirs at higher pressure. Moisture in atmospheric air condenses into water when compressed. Air dryer with desiccant filter is used to remove water to supply dry air. Higher oil carryover from compressor may also result in more oil particles being pumped into the system. Life of desiccant used in air dryer will be reduced due to deposition of these oil particles. Adding a mechanical condensate separator before air dryer removes heavier oil/water particle from compressed air by centrifugal action. Thus, it helps in extending the life of desiccant in air dryer and protects downstream products of braking system from rust formation due to moisture content. In this paper, separation of condensate from air medium inside the condensate separator is simulated as transient CFD simulation using multiphase Algebraic Eulerian model in
Vasanth Bharath, S.Dinesh Kumar, J.Suresh, S.Hariharan, R.
The existing compressor plants at railroad marshalling yards (MYs) are equipped with automatic compressed air supply control systems. However, this is implemented using outdated and ineffective methods. Taking into account the current trends in the field of three-phase motor control, as well as the requirements for energy saving, the most effective is the frequency regulation of performance. The work provides a justification for the need to use a variable frequency drive of a compressor unit (CU). A mathematical model has been developed for controlling an asynchronous motor (AM), taking into account the setting coefficient of performance. As a result, a computer simulation model for controlling the drive motor of a reciprocating compressor at an MY has been proposed and tested. The diagrams and values obtained made it possible to study in detail the automatic control system of the drive and select the optimal control laws for the frequency-controlled unit. An analysis of the results of
Satsiuk, AleksandrVolodarets, MykytaGritsuk, IgorLitikova, HalynaPodnebenna, SvitlanaBelousov, EvgenVolkov, VladimirAhieiev, MaksymPohorletskyi, DmytroZinchenko, SerhiiKhudiakov, Igor
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