Piston Valve Research Articles

Preliminary Analysis and Optimization via CFD of a Liquid Hydrogen Pressure Regulating Piston Valve

Due to their high reliability and precision, piston valves are frequently used for pressure regulating applications. Particularly in the aerospace industry, where cryogenic fluids such as liquid hydrogen are frequently used, the design and operation of piston valves become crucial. The current state of advancement of this technology in the cryogenic field is still in its early stages, owing to the difficulties in designing such complex systems in harsh environments. This justifies the need for further in-depth studies and analysis using CFDs tools and predictive models. In order to ensure an optimal and efficient use of a piston pressure regulating valve in cryogenic environment, it is necessary to understand the strengths and limitations of this technology in an extreme thermal and mechanical condition. The presented work concentrates therefore on a preliminary analysis and optimization of a piston valve operating in liquid hydrogen flow field, for pressure regulating applications. Particular focus will be dedicated to the overall dynamics of the main body of the piston, in terms of robustness and controllability of the desired response of the system. The dynamics of the piston within an extremely low-viscous flow, as well as the thermodynamic and fluid dynamic aspects of the valve system, will be discussed. Simulations of the flow field will be performed through CFD tool, crossing the results with the dynamics of the simulated system response through and implemented Simulink model. The obtained results will be then critically analysed in order to suggest possible optimization of the valve in the locations where the system is most affected from a thermal and mechanical standpoint.

Analysis of the causes of piston valves failures compressors and ways of improvement their designs

Analysis of the causes of piston valves failures compressors and ways of improvement their designs

Analysis of Causes of Combustion Failure in Burner Incinerators at MT. JS INEOS INNOVATION

Abstraction-Incinerator is an auxiliary machine designed as the main combustion chamber to burn wasted oil after going through the heating process in a sludge incinerator tube. The use of the incinerator on the ship aims to burn the waste on the ship and also burn dirty oil. Based on the author's research, the operation of the incinerator on board is still not optimal due to the failure of the combustion in the incinerator burner. This study aims to find out the causes and efforts to solve the problems raised by researchers, namely combustion failure in the incinerator burner at MT. JS Ineos Innovation
 This study used a descriptive qualitative method. By using fishbone analysis techniques, researchers identified the factors and efforts made related to combustion failure at the Incinerator burner at MT. JS Ineos Innovation. Source of data taken from primary and secondary data. Data collection was carried out by interviews, observation, documentation, and literature study which was carried out during the research.
 Based on the research results, it can be concluded that combustion failure in the incinerator burner is caused by several factors, including a dirty burner nozzle, damaged steam valve, decreased steam supply from the steam service line, and jammed piston valve in the sludge dosing pump incinerator. Efforts made to overcome the occurrence of combustion failure at the incinerator burner are carrying out cleaning of the incinerator burner, carrying out maintenance or replacement of the steam valve, increasing the steam intensity from the steam service line to the inlet heater incinerator, and carrying out maintenance and repair of the piston valve in the sludge. dosing pump incinerator.

리니어 압축기에서 예압축을 위한 체크 밸브 피스톤 성능 연구

리니어 압축기에서 예압축을 위한 체크 밸브 피스톤 성능 연구

Thermodynamic analysis of heat transfer reduction in spark ignition using thermal barrier coatings

This work uses a 0D thermodynamic engine model coupled to a 1D surface temperature solver to study the potential of low thermal inertia thermal barrier coatings (TBCs) on combustion chamber surfaces to increase the efficiency of spark ignition engines. Under ideal conditions, coating the piston crown, head, and valve faces with a TBC with a thermal inertia of 640 J/m2 K s1/2 resulted in less than a 1% relative improvement in efficiency. Despite using a low thermal inertia coating to avoid open cycle charge heating, the reduction in closed cycle heat transfer, which is the pathway to increasing efficiency, increased knock propensity. Therefore, any efficiency gain through closed cycle heat transfer reduction in spark ignition is offset by the need to retard spark timing to counter knock. An exergy analysis of completely blocking heat transfer for a 10 crank-angle degree window showed that on a low compression engine, like those used for stoichiometric gasoline spark ignition, the maximum efficiency gain achievable was limited compared to a higher compression ratio engine. Furthermore, the high gas temperatures of stoichiometric operation mean that even state-of-the-art TBCs cannot elevate surface temperatures enough purely through temperature swing to achieve a significant reduction in heat transfer near top dead center, where work availability is highest. Overall, these results indicate that low thermal inertia TBCs are ill-suited for achieving an efficiency benefit in spark ignition through a heat transfer reduction pathway. Instead spark ignition TBC research should explore ways to use low thermal inertia TBCs to achieve open cycle charge cooling to reduce knock propensity.

K9 자주포 엔진용 오일펌프 조립체의 개선에 관한 연구*

This paper is on the improvement of the oil pump assembly for preventing low oil pressure symptoms of the K9 Self-Propelled howitzer engine. Although the TBO(Time Between Overhauls) of K9 self-propelled howitzer engine is 1,500 engine operating hours, 13.37 % of K9 Self-Propelled howitzer engines which were operated for only hundreds of hours suffered low oil pressure symptoms and failed to operate normally. Detailed investigation into the engine was conducted to establish the cause and generation mechanism of the symptoms and it was found that oil leakage due to abrasive wear of pressure relief valve piston housing occurred in the oil pump assembly. To prevent abrasive wear of piston housing, new design concept and design parameters of pressure relief valve have been proposed. Performance, durability and system installation test on the prototype based on the proposed design were followed and results validated the proposed design. Oil pump assembly based on this study is applied to mass production.

Analysis of nonlinear vibration transmission through a vehicle suspension damper at low audio frequencies

Active control is an attractive solution to the problem of structure-borne interior road noise in cars. However, nonlinear suspension dynamics could limit the cancellation that can be achieved with a linear feedforward road noise control system. The hydraulic dampers in a vehicle suspension have previously been found to be a source of nonlinear vibration transmission at low audio frequencies. This paper presents experimental measurements and modelling of the front and rear suspension dampers in a test vehicle aimed at understanding the physical processes causing their nonlinear dynamics. Experiments are shown that highlight the different nonlinear effects present in the dampers, including friction and the mechanics of the piston valves. A suitable model was then selected from the literature, fitted to the measurements and validated. Analysis of the models revealed that, in the front damper, both friction and the valve mechanics contribute significantly to the damper’s nonlinear dynamics between 50–300 Hz. Friction in the rear damper is much less significant, meaning that its nonlinear dynamics are almost entirely caused by the piston valves. Although the front damper’s friction behaviour proved challenging to model, the effect of the piston valves was captured very accurately in both damper models.

Material compatibility of SI engine components towards corrosive effects on methanol-gasoline blends for flex fuel applications

The experimental study is conducted through static immersion of engine components to evaluate the material compatibility against the corrosive nature of methanol. The investigation is performed at room temperature along with different fractions of methanol in gasoline (M0, M20, M50, and M100) for varied durations of 60, 120, and 180 days. Further, the surface characterization of metal samples and fuel properties are examined in previous and post-immersion test duration in order to comprehend the penetration of corrosion. Also, the impact of corrosion on morphological changes, composition and engender of oxide layers on the engine components are inspected by SEM/EDX and XRD. Similarly, the changes brought by corrosion products on the physical (density and viscosity) and chemical properties (calorific value and TAN) are investigated and compared before immersion. The result of the study demonstrates that increasing the methanol percentage intensifies the corrosiveness of fuel samples when exposed to metal samples. Additionally, it has been found that the presence of oxygen in methanol significantly contributes to an increase in metal corrosion. Based on the investigational outcomes, comparatively the piston exhibits lesser resistance towards corrosion than the piston ring and valve. On the other hand, corrosion attack on the engine component surfaces disclosed to M100 is higher relative to that of M50, M20 and M0. Consequently, the characteristics of fuels are changed with respect to corrosion intensity and M100 has a higher variation among fuel samples. Therefore, the application of methanol in a lower concentration is suitable for SI engines in accordance with material compatibility since the corrosiveness of methanol is minimal on the engine components. Finally, this work reports some proposals based on the experimental outcomes to exalt the performance of engine components against the corrosive nature of methanol for flex-fuel engines (FFE).

PD controller design for a system of a valve controlled hydromotor

PD controller design methodology based on D-decomposition is considered in this paper. The method consists in tuning two parameters of a controller: proportional (P) and differential (D). The method was applied to a hydromotor controlled by a valve according to the position of the valve's piston. The results obtained in this paper show the good performance of the automatic control system in comparison with other methods of controller design and other controllers designed with the same method on the valve controlled hydromotor system.

EXPERIMENTAL INVESTIGATION OF LOW HEAT REJECTION WITH RETARDED INJECTION TIMING ON DIESEL ENGINE USING KARANJA OIL METHYL ESTER

Rising demand for fuel will now pose a significant risk for global pollution levels in various applications. The biodiesel of Karanja oil methyl ester (KOME), an alternative to diesel fuel, is a potential source of unspent fuel in India. Karanja oil contains fatty acid esters, which are environmentally friendly fuel. This experiment aimed to research low heat rejection using Karanja oil methyl ester with retarded injection timing diesel-fueled. The piston, cylinder walls, and engine valves were coated with a 0.5 mm thickness of partially stabilized zirconium (PSZ) without affecting the engine compression ratio. Experiments in the engine with and without coating were carried out using Karanja oil methyl ester. The results showed that Karanja oil methyl ester's specific fuel consumption a retarded timing (RT) with coated engine decreased by 7.4 percent and the brake thermal efficiency improved by 5.5 percent compared to the conventional engine with diesel fuel. CO and UBHC emissions on the LHR with RT engine are lower, whereas the zirconia coating has increased NOx emissions.

Effect of diesel engine modification operated with karanja biodiesel and its blends

• Increased biodiesel blends, such as B30 and B40, result in decreased engine performance (BTE) and higher smoke, HC and NOx emissions. • The B20 blend is an appealing alternative because it enhances engine performance while lowering emissions. • The country’s economy benefits from the substitution of fossil fuels for indigenous renewable and alternative fuels. • This alternative is more realistic because there are abundant resources of non-edible oil seeds for biodiesel preparation and biodiesel production costs are becoming more affordable. Growing attention in studying renewable and alternate fuels for internal combustion (IC) engines has been increased by concerns about improving engine performance while reducing emissions to satisfy EURO standards and to fulfil increasing energy demands for a growing population. Biodiesels are a possible replacement to diesel fuel since, they are renewable and have qualities similar to fossil diesel. For diesel engines, biodiesel generated from Karanja oil is a better diesel substitute. The use of alternative fuels in a CI (Compression ignition) engine reduces performance while also increasing hydrocarbon (HC) and carbon monoxide (CO) pollutants. However, making the engine entirely adiabatic by combining biodiesel with diesel and applying thermal barrier coatings (TBC) to the piston, cylinder wall, and inlet and outlet valves will improve overall engine performance. In light of this, TBC diesel engine components coated with partly stabilized zirconia (PSZ) and aluminium oxide (Al 2 O 3 ) ceramics were tested in a diesel engine using Karanja oil methyl ester (KOME) and its mixtures. Both diesel and KOME and its blends had their brake thermal efficiency (BTE) emissions measured before and after coating, and the obtained results were matched. Engine performance is nearly comparable with acceptable emission requirements while using B20 powered biodiesel and a PSZ coated engine. Among the biodiesels tested, the maximum BTE was recorded with diesel which was 2.79%, 5.89%, 7.75%, 9.64% and 14.03% greater than B10, B20, B30, B40 and B100 fuel blends. From various fuels tested, the minimum smoke emissions were recorded with diesel which was 6.06%, 12.9%, 20.68%, 29.62% and 39.88% lower than B10, B20, B30, B40 and B100 fuel blends.

An experimental investigation on ceramic coating with retarded injection timing on diesel engine using Karanja oil methyl ester

Rising demand for fuel will now pose a major risk for global pollution levels in various applications. The biodiesel of Karanja oil methyl ester (KOME), an alternative to diesel fuel, is a potential source of unspent fuel in India. The goal of this experiment was to research low-heat rejection using Karanja oil methyl ester with retarded injection timing diesel-fuelled. With 0.5 mm thickness of partial stabilised zirconium (PSZ), the piston, cylinder walls and engine valves were coated without affecting the engine compression ratio. Experiments in the engine with and without coating were carried out using diesel or Karanja oil methyl ester. The results showed that the specific fuel consumption for Karanja oil methyl ester with a retarded timing-reduced engine decreased by 7.4% and the brake thermal efficiency improved by 5.5% compared to the conventional engine with nice diesel fuel.

Impact of a Thermal Barrier Coating in Low Heat Rejection Environment Area of a Diesel Engine

The most recent developments in Thermal Barrier Coating (TBC) relate to engine performance, manufacturing and other related challenges. TBC on the piston crown and valves to enhance engine characteristics while using diesel and Mahua Methyl Ester (MME) as a petroleum fuel has a great sustainable development. For this utility, a Direct Injection (DI) conventional diesel engine was renewed to an LHR engine by applying 0.5 mm thickness of 3Al2O3-2SiO2 (as TBC) onto the piston crown and valves. The MME is used in the LHR (Low Heat Rejection) engine. For examination, the fuel injector pressure is set at 200 bar. Compared to a standard DI diesel engine, the results demonstrate that the application of TBC boosts brake thermal efficiency to 13.65% at 25% load. The LHR engine’s SFC and BTE significantly improved at full load while using MME fuel. The lower temperature of exhaust gases is achieved by combining MME and diesel fuels with TBC. It was observed that both MME with and without TBC significantly reduced the smoke density. In addition, it was exposed that using MME fuel with TBC very slightly reduced carbon monoxide emissions under all loads. It was also shown that MME with TBC significantly reduced environmental hydrocarbon emissions at all loads.

Study on noise reduction method of main noise transmission path of axial piston pump with new damping material

Axial piston pump is complex fluid machinery with mechanical fluid coupling, and it has the characteristics of multiple noise sources. In order to solve the high noise problem of axial piston pump, this paper proposes a noise reduction method by identifying the main noise sources of axial piston pump and laying new damping materials to reduce noise. It breaks through the existing method of optimizing the parameters of piston pump shell and valve plate structure. A multi-parameter trajectory sensitivity identification and noise reduction method for vibration transmission path of axial piston pump is proposed in this paper. First, the lumped parameter method is used to establish the mathematical model of vibration transmission path of axial piston pump. The sensitivity of structural vibration response to transmission path multi-parameters are analyzed based on trajectory sensitivity method. The most sensitive parameters in the main noise transmission path are determined. Then, the experimental study of radiated noise transmission path of axial piston pump is carried out. A new type of viscous damping material is proposed to reduce the noise on the transmission path of the main noise source. The experimental results show that the noise of piston pump is reduced by 2.32 dB. The research results provide a new method and way for the design and manufacture of low noise piston pump.

A numerical evaluation and guideline for thermal barrier coatings on gasoline compression ignition engines

The application of thermal barrier coatings (TBCs) for internal combustion engines has drawn more research attention in recent years due to the improved coating technology and advanced material properties. This paper presents the combination of thermal barrier coatings with an advanced combustion concept: gasoline compression ignition (GCI). This study aims to evaluate the coating performance with GCI combustion on Aramco’s light-duty GCI engine. The thermodynamic engine model has been established and collaborated with CFD results to investigate thermal barrier coatings for GCI with a PPCI-diffusion combustion strategy primarily at a load of 23.5 bar IMEPg. Two real-world coating materials were pre-selected as Gen.1 and Gen.2 candidates. The investigation consists of three main topics: the effect of coating thickness on GCI, the effect of intake boost on the performance of traditional coatings and temperature swing coatings, and the effect of combustion chamber coverage on engine performance. The result shows that the TBC thickness became the key parameter to optimize for TBC with GCI combustion mode, and in the end, 250–500 microns is recommended based on the temperature limit of ceramic material. It was also found that the high level of intake boosting could significantly alleviate the charge heating penalty. The coverage of piston, engine head, and both intake and exhaust valves should be applied to achieve the highest efficiency gains. It was found that the gain ratio from each chamber component can be drastically different at different loads.

Experimental Examination on Performance and Emission of a Coated Diesel Engine Fueled with Diesel and Pre-Heated Coriander Oil Blends

Abstract The aim of the study is to determine the effects of the preheated coriander seed oil, used as fuel, on the performance and the emission characteristics of the ceramic coated single-cylinder diesel engine. In this study, the piston, exhaust, and inlet valve of a single-cylinder air-cooled diesel engine were coated with Cr3C2 at 300 µm thickness. Pure coriander oil was mixed with diesel fuel volumetrically at the rates of 30% and 50%. The plasma spray method was used as the coating method. It was determined that the preheating process provided a more suitable fuel flow, decreased the viscosity of the coriander oil and also the coating process decreased CO, soot and HC emissions but increased NOx, thermal efficiency, and EGT.

Intake Manifold Flow Study using Numerical Method with all Runners Opened

Intake manifolds have to be designed to improve engine performance by avoiding the phenomena like inter-cylinder robbery of charge, inertia of the flow in the individual branch pipes, resonance of the air masses in the pipes and the Helmholtz effect. The objective of work is to predict and analyze the flow through intake manifold of four cylinder spark ignition engine. One of the important factors is air flow inside the intake manifold; the ideal intake manifold distributes flow evenly to the piston valves. The structural analysis has been conducted to decide the thickness and material that is suitable for intake manifold to withstand bursting pressure. Three-dimensional inlet manifold was modeled in ANSYS workbench and numerically analyzed by using the commercially available FLUENT software to study the pressure, velocity and flow characteristics inside the runner. The steady state analysis has been carried out for three for All runners open, The predicted results of total pressure loss and total outlet mass flow were discussed. Inlet pipe and plenum connection creates a back step geometry which causes more total pressure loss due to flow recirculation in conventional model. Tapering the geometry is causing more inlet mass flow due to reduction in total pressure loss in the plenum chamber.

Variable Valve Strategy Evaluation for Low-Load Operation in a Heavy-Duty Gasoline Compression Ignition Engine

By harnessing gasoline’s low reactivity for partially premixed combustion promotion, gasoline compression ignition (GCI) combustion shows the potential to produce markedly improved NOx-soot trade-off with high fuel efficiency compared to conventional diesel combustion. However, at low-load conditions, gasoline’s low reactivity poses challenges to attaining robust combustion with low unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions. Increasing the in-cylinder charge temperature by using variable valve actuation (VVA) can be an effective means to address these challenges. In this numerical investigation, VVA strategies, including (1) early exhaust valve opening (EEVO), (2) positive valve overlap (PVO), and (3) exhaust rebreathe (ExReb), were investigated at 1375 RPM and 2 bar brake mean effective pressure in a heavy-duty GCI engine using a market-based gasoline with a research octane number (RON) of 93. The total residual gas level was kept over 50% to achieve an engine-out NOx target of below 1.5 g/kWh. For a complete engine system analysis, one-dimensional (1-D) system-level modeling and three-dimensional (3-D) computational fluid dynamics (CFD) analysis were close-coupled in this study. Performance of the VVA strategies was compared in terms of in-cylinder charge and exhaust gas temperatures increase versus brake-specific fuel consumption (BSFC). The EEVO strategy demonstrated in-cylinder charge and exhaust temperature increase up to 130 and 180 K, respectively. For similar in-cylinder charge temperature gains, the ExReb strategy demonstrated 11% to 18% lower BSFC compared to the EEVO strategy. This benefit primarily originated from a more efficient gas-exchange process. The PVO strategy, due to the valve–piston contact constraint, required excessive exhaust back-pressure valve (BPV) throttling for hot residuals trapping, thereby incurring higher BSFC compared to ExReb. In addition, the ExReb strategy demonstrated the highest potential for exhaust temperature increase (up to 673 K) among the three strategies. This was achieved by ExReb’s maximum air-fuel ratio reduction from high internal residuals mass and BPV throttling. Finally, the ExReb profile was optimized in terms of the peak lift, the duration, and the location for maximizing the fuel-efficiency potential of the strategy.

Novel resonance stability criterion for the 2D magnetically levitated servo-proportional valve

The leakage of the pilot stage of the 2D valve mainly depends on the size of its initial opening. According to the Routh criterion, the pilot stage of the two-dimensional magnetically levitated servo-proportional valve (2D-MSP valve) needs to be designed to have certain positive values to increase the damping ratio to improve valve stability, which leads to the leakage flow representing a non-negligible power loss. In order to reduce leakage flow and achieve goal of energy saving, this paper presents a novel resonance stability criterion by considering nonlinear characteristics of the fluid dynamic system. First, the 2D-MSP valve is regarded as a three-way valve-controlled differential cylinder system. Based on the frequency response of the resonance state, the energy conservation method is used to solve the flow “backfilling” area, the motion equation of the cylinder piston (valve spool displacement) and the pressure waveform of the sensing chamber under different opening and pressure amplitude ratio. Then, the analytical expression of the resonance peak amplitude is obtained and the resonance stability criterion is deduced. The result is compared with the Routh stability criterion, which illustrates that the positive openings of the pilot stage can be reduced to one-third of the original value. The prototype valve is then designed and manufactured based on the resonance stability criterion. The dynamic and static characteristics under different system pressures are measured. Experimental results show that the prototype valve is an over-damped system without any overshoot, which has excellent working stability, and its static and dynamic performance can meet the demands of the industry servo-proportional control system. The research work validates the effectiveness of the proposed resonance stability criterion.

Influence of Homogenization in the Physicochemical Quality of Human Milk and Fat Retention in Gastric Tubes.

The retention of human milk nutrients in gastric tubes used to feed premature infants is a challenge to be overcome. To evaluate (1) the performance of six homogenizers (mixing processor, piston valve, ultrasonic bath, ultraturrax, stirring mixer, and ultrasound probe) for the fat retention reduction in gastric tubes; (2) the influence of the best homogenization conditions on the fatty acid and protein profiles of human milk; and (3) the cost/benefit ratio for the inclusion of homogenization as a new step in human milk processing. The influence of different levels and times of homogenization on reducing fat retention of human milk in probes was evaluated in this comparative prospective cross-sectional study. After homogenization, human milk flowed through a gavage and infusion pump apparatus used for feeding. Fat content was quantified before and after feeding. The techniques that reduced fat globule sizes and/or promoted a lower percentage of fat holding were evaluated for efficiency, variations in the fatty acid and protein profiles, and energy density and operating costs. Homogenization led to a reduction in fat retention in feeding probes. The mixer processor and the ultrasound probe reduced fat retention by 99.23% (SD = 0.07) and 99.95% (SD = 0.02), respectively, and did not negatively influence fatty acid and protein profiles. The mixer processor demonstrated low energy density and low cost for human milk processing. Homogenization promoted reduced fat retention in the feed probe and could help maintain fat nutrients of human milk during enteral feeding.