Compressor Chamber Research Articles

Performance investigation of a high-temperature absorption-compression heat transformer with liquid refrigerant injection

The high-temperature heat pump technology is a promising approach to utilizing low-temperature waste heat while meeting industrial demands for high-temperature heat. However, existing high-temperature heat pump systems face challenges including insufficient temperature lift, system complexity, and rapid performance degradation at high output temperature. This paper proposes a novel, structurally simple high-temperature absorption-compression heat transformer, aiming to recover heat below 100 °C and achieve a large temperature lift above 70 °C. The system is analyzed from the aspects of energy, exergy, key parameters that impact its performance, and techno-economic comparison. Results show that injecting liquid refrigerant into the compressor chamber mitigates high superheat effects on the compressor, allowing for higher absorption pressure. The system achieves an output temperature of around 170 °C, with the compressor outlet temperature below 120 °C. Moreover, some liquid refrigerant evaporates by absorbing compressor superheat. This reduces power consumption of the compressor, heat input of the evaporator, and overall system exergy loss. Thus, the proposed system demonstrates improvements of 6.5 % and 7.5 % in coefficient of performance and exergy coefficient of performance, respectively. Besides, it is feasible to achieve absorption temperatures exceeding 170 °C by increasing the solution concentration or the pressure ratio, with the former being the more cost-effective approach. Furthermore, the specific costs of the proposed system are more than 20 % lower than those of other types of high-temperature heat pumps, demonstrating its superior economic feasibility.

Моделирование работы газотурбинной установки SGT5-4000F с исследованием влияния режимных и климатических факторов на устойчивость горения в камере сгорания

When regulating gas turbine units, it is necessary to be confident in the stable combustion process in the combustion chambers, considering the dynamics of the processes and changes of external climatic factors. Many scientific studies are devoted to the problems of experimental research and mathematical modeling of processes in combustion chambers. The possibilities of flame failure, expansion of the lower limit of combustion, determination of the stable position of the flame front and other issues have been assessed. Even though the problem of design of mathematical models and their use remains relevant. The purpose of this research is to model and study the influence of operation and climatic factors on the stability of combustion in the combustion chamber of the SGT5-4000F gas turbine unit. The subject of the research is the SGT5-4000F gas turbine unit with a low-emission combustion chamber. The simulation model of the gas turbine unit has been developed in the environment of dynamic modeling of technical systems SimInTech. The research is carried out using theoretical methods of calculating fuel combustion, thermodynamic foundations of the theory of gas turbine engines, methods of mathematical and simulation modeling, as well as data from the archive of automated process control systems. A simulation model of SGT5-4000F gas turbine unit has been developed. It is distinguished by the ability to assess the proximity of the compressor operating mode to the stability limit and determine the boundaries of stable combustion procedure in the combustion chamber, considering environmental climatic factors. The authors have studied the stability of the compressor and combustion chamber. The results of the experimental studies of a gas turbine unit in the operating load range from 113 to 282 MW and in the range of outside air temperature from –12 to 30 °C have shown that the combustion process in the combustion chamber is unvarying over the entire operational stress spectrum. The results obtained are verified by comparing model values with technological parameters of a gas turbine unit taken from the archive of the power plant control system. The authors have assessed the influence of electrical load on the performance indicators of a gas turbine unit at outdoor temperatures of +30, +15 and –12 °C. According to the results of simulation modeling, the model of SGT5-4000F gas turbine unit is found to be adequate. The developed model can be used as a tool at the stage of functional and technological design of automated control systems for the development of effective automatic control systems.

Research on hydrogen leakage and diffusion mechanism in hydrogenation station

As a clean, efficient and sustainable energy carrier, hydrogen energy has been accepted as one of the main directions of future energy development. In this paper, a hydrogenation station providing compressed hydrogen outside was adopted as the research object. Based on finite element method and virtual nozzle model, the influence of leakage of main equipment in hydrogenation station on the distribution of combustible hydrogen was investigated, including hydrogen storage tank group, tube trailer, compressor chamber and hydrogenator. The results showed that the shape and volume of the combustible hydrogen cloud generated by the leak were influenced by obstacles, hydrogen storage pressure, and wind velocity. The disturbance of external wind and the decrease in hydrogen storage pressure will have a positive impact on the reduction of leaked volume. The diffusion of combustible hydrogen clouds can be exacerbated by complex structure of obstacles, while partition wall in the adopted hydrogenation station model can limit the combustible hydrogen cloud in the process area. These conclusions can provide guidance and reference for the risk prevention measures of hydrogenation station.

Monitoring and characterization of particle contamination in the pulse compression chamber of the OMEGA EP laser system

Abstract The laser-damage performance of optics is known to be negatively affected by microscale particle contamination induced by the operational environment. This work investigates the properties of particles accumulating in various locations near critical optics inside the OMEGA EP grating compressor chamber during quarterly operational periods over a 2-year duration. The particles found were characterized using optical microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The analysis indicates significant concentrations of micrometer- to nanometer-scale particles inside the vacuum chamber, with higher values observed near the port leading to the OMEGA EP target chamber. The distribution of the chemical composition of these particles varies between collection periods. Although understanding of the mechanisms of particle generation and transport remains uncertain, the hypothesis is that this particle load represents a risk for contaminating the surfaces of high-value optics located inside the chamber, including the compression gratings and deformable mirrors, and therefore affecting their laser-damage resistance and overall operational lifetime.

Improving the efficiency of an aircraft power plant with a turboprop engine based on water-methanol mixture injection

This paper considers a technique for modernizing the power plant (PP) of a regional aircraft. The modernization is based on the injection of water or a water-methanol mixture into the compressor or combustion chamber of a turboprop engine (TPE). An algorithm has been developed for the thermodynamic calculation of TPE parameters, taking into consideration the injected mixture; the mathematical model (MM) has been improved. Methodical studies of the operability and range of application of the improved MM were carried out. The results of mathematical modeling were validated. For verification, the AI-450M turboshaft engine produced by GP Ivchenko-Progress (Ukraine) was used as an object of research. Based on the improved MM, a software module has been developed to study the performance characteristics of a regional aircraft with a TPE. The influence of water injection and a water-methanol mixture on the TPE operating process and the operational characteristics of a regional passenger aircraft has been studied. The proposed measures could be implemented in existing TPEs. This would allow the operation of aircraft without significant modernization of the airport infrastructure. For TPE, the injection of water and a water-methanol mixture is an alternative way of boosting in order to temporarily improve performance. A given modernization technique could improve the TPE power up to ~10 %, as well as reduce the amount of harmful emissions. The results obtained showed a satisfactory convergence of estimated and experimental data. The error of the results under the accepted assumptions does not exceed 3 %. The calculation results demonstrate the advantages of injection at the take-off stage of the aircraft to reduce the take-off distance (up to 45 % in hot conditions TAMB=+30 °C) and reduce the time of climbing the echelon (~10 %)

Mathematical modeling of various forces acting on piston rod packing rings

Piston rod packing, a critical part of compressor provides dynamic sealing surrounding the piston rod. Typically, casings with one or more rings in each, are bolted to the cylinder head using the flange for providing effective sealing. During operation the packing rings are subjected to cyclic loads under high pressure and high-speed operating conditions. The pressure to which packing rings are subjected is usually as high as the pressure in compressor chamber. Failure of the packing to operate satisfactorily can result in plant downtime which eventually may affect the output. Hence, packing rings need to be critically designed. In this paper an attempt is made to develop a mathematical model of various forces and pressures acting on packing ring with respect to crank angle. The paper also illustrates the approach for calculation of axial and radial thickness. Distorted profile predicted using the given Fourier series can be used to calculate the leakage area. Compressor reliability and cost-effectiveness can be effectively predicted using the developed model.

Towards the Large-Eddy Simulation of a full engine: Integration of a 360 azimuthal degrees fan, compressor and combustion chamber. Part I: Methodology and initialisation

Optimising the design of aviation propulsion systems using computational fluid dynamics is essential to increase their efficiency and reduce pollutant as well as noise emissions. Nowadays, and within this optimisation and design phase, it is possible to perform meaningful unsteady computations of the various components of a gas-turbine engine. However, these simulations are often carried out independently of each other and only share averaged quantities at the interfaces minimising the impact and interactions between components. In contrast to the current state-of-the-art, this work presents a 360 azimuthal degrees large-eddy simulation with over 2100 million cells of the DGEN-380 demonstrator engine enclosing a fully integrated fan, compressor and annular combustion chamber at take-off conditions as a first step towards a high-fidelity simulation of the full engine. In order to carry such a challenging simulation and reduce the computational cost, the initial solution is interpolated from stand-alone sectoral simulations of each component. In terms of approach, the integrated mesh is generated in several steps to solve potential machine dependent memory limitations. It is then observed that the 360 degrees computation converges to an operating point with less than 0.5% difference in zero-dimensional values compared to the stand-alone simulations yielding an overall performance within 1% of the designed thermodynamic cycle. With the presented methodology, convergence and azimuthally decorrelated results are achieved for the integrated simulation after only 6 fan revolutions.

Towards the Large-Eddy Simulation of a full engine: Integration of a 360 azimuthal degrees fan, compressor and combustion chamber. Part II: Comparison against stand-alone simulations

Unsteady simulations of various components of a gas-turbine engine are often carried out independently and only share averaged quantities at the component interfaces. In order to study the impact and interactions between components, this work compares results from sectoral stand-alone simulations of a fan, compressor and annular combustion chamber of the DGEN-380 demonstrator engine at take-off conditions against an integrated 360 azimuthal degrees large-eddy simulation with over 2.1 billion cells of all previously listed components. Note that, at take-off conditions the compressor works at transonic conditions and generates an upstream-propagating shock that interacts with the fan modifying the shape of its wake with respect to the stand-alone simulation. Furthermore, the shock is seen as a tone in the pressure spectra at half the impeller blade passing frequency in the forward region of the engine. In the aft region, time-averaged fields are overall similar between stand-alone and integrated simulations but show a deviation in the azimuthal position of the hot-spot at the exit of the combustion chamber due to the addition of the diffuser. Pressure fluctuations generated in the compressor are captured in the combustion chamber as tones in the temperature and pressure spectra at the impeller blade-passing frequency and harmonics as well as an increase in the root-mean-square pressure.

Numerical investigation of oil injection in screw compressors

Oil injected screw compressors are commonly used in the industry. The position and amount of oil injection are determined experimentally or by heat balances with an assumption of uniform oil distribution in the compression chamber, which is not validated. This paper presents a study on the oil distribution within a screw compressor chamber using Computational Fluid Dynamics (CFD) with Volume of Fluid (VOF) multiphase model. Prerequisite for using CFD in screw compressors is a body fitted numerical mesh produced by software SCORG. The analysis was carried out on a newly designed screw compressor with a 4–5 lobe combination. It was found out that injecting the oil through two separate ports , one on each rotor, has advantages compared to the injection through a single port. The injection ports are conveniently positioned to ensure an even oil distribution within the compression chamber. If the same amount of oil is injected through the two separate ports instead of the originally designed single port , the maximum gas temperature within the chamber could be reduced by 30°–35 °C leading to reduction in specific power by 1.8%. Techniques used in this study can improve the performance and efficiency of a wide range of screw compressors.

Effect of polyolester oil-based multiwalled carbon-nanotube nanolubricant on the coefficient of performance of refrigeration systems

This paper presents experimental and theoretical findings on the effect of polyolester oil-based multiwalled carbon nanotube nanolubricant on both the heat dissipation in the evaporator and the power consumption of the compressor of a refrigerator. The nanolubricant containing multiwalled carbon nanotube with 0.1 wt% Triton X-100 surfactant was manufactured using a two-step method. The pressure in the test cell containing R134a and the nanolubricant was measured for different exposure times to observe the behavior of the suction pressure in the compressor chamber containing the nanolubricant. Based on the results, a model for predicting the suction pressure behavior was established. The developed model was applied, and it was found that the power consumption of the compressor containing the nanolubricant could be reduced by up to 17%. In addition, the modified flow boiling heat transfer coefficient of the evaporator considering the nanolubricant was theoretically derived using a property model of the nanolubricant. The modified model showed that the flow boiling heat transfer coefficient of the evaporator containing the nanolubricant could be improved by approximately 5.8%. Finally, the enhancement in the coefficient of performance of the refrigerator containing R134a and the nanolubricant was analyzed using the results for the power consumption of the compressor and the flow boiling heat transfer coefficient of the nanolubricant in the evaporator.

Long-term monitoring the damage performance of multilayer dielectric grating samples residing inside the compressor chamber of the OMEGA EP laser

Understanding of the laser-induced damage threshold and impact of air–vacuum cycling of the optical components in short-pulse laser systems is of fundamental importance. We report the results of a damage-testing campaign that monitored representative pulse compression grating samples that were positioned inside the OMEGA EP grating compressor vacuum chamber during normal operation and routinely damage tested on every quarterly vent for a period of about 10 years. The evolution of their damage resistance under 10-ps and 100-ps pulse lengths are associated with a significant degradation of the laser-induced damage thresholds, which is comparatively larger at 100 ps, is described.

An experimental investigation of oil circulation ratio influence on heating performance in an air condition heat pump system for electrical vehicles

Oil, lubricating and cooling the sliding parts of the compressorcomponents exposed to friction, could prevent refrigerant gas leakage in compressor chamber of vapor compression air conditioning system. For air condition heat pump system in electric vehicles, no oil circulating routes and oil separator are used to drive oil from system to compressor, making oil retainedmore difficult to control. Oil accumulated in heat exchanger and expansion valve would enhance pressure drops and reduce heat transfer capacity, leading to decrease of entire heating performance in cold climate. In this paper, a newly designed air conditioning heat pump system with R134a and PAG46 oil is introduced firstly, and oil circulation experiments were conducted on a full-scale electric vehicle. Typical heat transfer characteristics and system performance parameter were recorded and analyzed subsequently under different compressor oil charge conditions, including excessive charge and insufficient charge. Oil circulation rates in system were also measured and exhibited an increasing trend with compressor oil charge mass. Furthermore, heating performances of the system under different oil circulation rate were compared by various heating capacity and pressure drops. Results showed that both excessive and insufficient charge might decrease heating performance, i.e., determination of suitable oil charge is quite important for air condition heat pump system.

Thermodynamic and economic analysis of a micro-combined polygeneration system coupled with solar energy and fuels for distributed applications

A novel micro-combined polygeneration system based on solar energy and fuels is designed with aim to simultaneously satisfy energy demands of electricity, heating and cooling in distributed areas. Integration solar radiation with conventional natural gas-fired power systems is conceived to eliminate existing disadvantages of low efficiency and high cost for fuel-only and solar-only plants. Thermodynamic and economic analyses are evaluated to explore performance of proposed systems with three working fluids. Energetic and exergic efficiencies are individually 0.839 and 0.4536, 0.8721 and 0.5852, and 0.8656 and 0.5825 for N2-, He- and Ar-based micro-combined systems under specified power capacity of 100 kW. Solar collector field, compressor, turbine and combustion chamber exhibit four largest exergy destruction, followed orderly by heat exchanger, generator, condenser, evaporator, throttling valve and pump. Preliminary economic analysis indicates that levelized electricity costs of N2-, He- and Ar-based micro-combined systems are 0.112, 0.103 and 0.101 $ kWh−1 with corresponding payback periods of 4.563, 5.090 and 5.138 years. Parametric analysis reveals that five operating parameters (compression ratio, turbine inlet temperature, solar collector field outlet temperature, generator outlet temperature and split ratio) exert noticeable influence on thermal efficiency of micro-combined systems. In conclusion, proposed micro-combined polygeneration system achieves efficient conversation of thermal energy into electricity, heating and cooling at a rational energy utilization for distributed areas.

Analisa Overheating Pada Kompresor Sullair LS16-60/75/100

Background The problem faced is overcoming the Overheating of the Screw Air Compressor, the air circulation in the compressor chamber is not good, the Oil has passed the Normal Working Hours, the Oil Separator is clogged, the heat dissipation is blocked in the Coller Unit, the oil filter is clogged with dirt, the Distribution Mechanism in the Oil Filter Housing The unit does not work. Aim of overcoming the overheating that occurs in the compressor which results in a decrease in air pressure on the engine in the production section, knowing the cause of the damage or downtime. Method used is observation of the compressor operation, and checking the compressor engine components. Results and Discussion Overheating on the compressor engine will have an impact on the performance of the engine itself and the air produced. Overheating in the compressor engine is caused by several things including poor air circulation, so the air gets hot and the engine performance decreases. Conclusion minimize damage caused by overheating is to carry out maintenance of the water cooler and oil coller

Mathematical model of air suspension with internal throttling of working fluid

The article describes a mathematical model of a two-mass vibrating system with an air suspension consisting of a two-chamber air compressor, the working and auxiliary chambers of which are connected to each other through an air throttle. The results of the research have been used to construct the amplitude-frequency characteristics of vertical displacements and accelerations of the suspended mass, and conclusions have been drawn.

Modeling coherent synchrotron radiation with a discontinuous Galerkin time-domain method

Coherent synchrotron radiation (CSR) remains a computationally difficult aspect in the numerical modeling of modern electron accelerators. In this paper, we present the theory and numerical implementation of a high-order discontinuous Galerkin method for computing CSR wake fields in a bunch compressor while including geometrical effects. We incorporate this method in our code: CSRDG (Coherent Synchtrotron Radiation with Discontinuous Galerkin). Using this code, wake potentials and associated quantities are calculated for the simple case of an electron bunch propagating along a single bend structure as well as for a complete bunch compressor chamber of the European XFEL.

TERJADINYA WARNING LIGHT FUELCLOG ENGINE TURBO PROP PW127F PESAWAT ATR 72-500

Aircraft Air Transport Region (ATR) 72-500 PK-WFG property of Wings Air Company used to engine PW127F, that is one of turbo prop engine type consist of centrifugal compressor and anullar combustion chamber. When going to RUN-UP engine occurred warning light fuel clog on indicator of fuel clog. Based on inspection indicator cockpit, engine fuel system, and engine component there is limit hard time of outlet fuel filter component reach on 1950 flight hours and contaminate a lot of debress on that surface. The effort to handle replaced outlet fuel filter component (PN: 24436361-01) with new item furhermore, perfomed leak check engine running by means of reference Aircraft Maintenance Manual (AMM 71-01-40). To ensure no leaked on engine and be able to operate as well. With the result that engine going to return to service and decent to flight. Keywords : Fuel System, Fuel Clog, Outlet Fuel Filter, Indicator Warning Light

Energy, exergy and sustainability assessments of a cogeneration system for ceramic industry

In this study, energy, exergy and sustainability analyses are applied in the ceramic sector to simulate gas turbine based cogeneration plant model. The cogeneration system mainly consists of a proposed gas turbine unit, a wall tile dryer and a ground tile dryer. The energy analysis is performed, and then the exergy and sustainability analyses are applied for the five different dead state (environment) temperatures varying from 10 °C to 30 °C (interval of 5 °C). It is found that the most energy efficient components are determined as the air compressor and combustion chamber, while the minimum one is obtained to be wall tile dryer (7.98%). The maximum sustainability and exergy efficiency (89.46%) are determined for the air compressor as at 10 °C dead state temperature. The cogeneration (overall) system has 17.51% energy efficiency; while its maximum exergy efficiency is found to be 29.98% at 30 °C environment temperature. The sustainabilities of the components are also directly proportional to their exergy efficiencies. Furthermore, the utilization of the gas turbine unit included cogeneration system can provide 0.1115 m3/s and 0.0732 m3/s natural gas saving for the ground and wall tile dryers, respectively.

Investigation of the influence of the number of vanes on the performance of a rotary vane compressor

We developed a mathematical model for determining the parameters of mass transfer in the compressor chambers during the processes of compression and discharge. The mass flow rates through the end and radial gaps were determined. Also we analyzed the processes of mass transfer in a clamped volume. We investigated the influence of the number of vanes on the compressor efficiency, taking into account changes in the compressor geometric parameters. We established that overflows through the end surfaces of rotor mainly affect the compressor performance. In order to reduce overflows during the period of discharge, it was proposed to increase the angle of closure of the discharge window at a fixed angle of its opening. The mathematical model allows one to make recommendations on the choice of the optimal number of vanes for a particular design.

Exergy analysis of a Brayton cycle with variable physical properties and variable composition of working substance

The exergy analysis of a Brayton cycle is performed in the paper. The four input variables: the ratio of the compressor exit and inlet pressures, the ratio of inlet temperature of gases in turbine and inlet temperature of air in compressor and the isentropic efficiencies of the compressor and turbine are analysed. The temperature ratio is varied in a way that the compressor inlet temperature of air is maintained constant, while the turbine inlet temperature of flue gases is varied from 900 to 1200°C. In the combustion chamber methane is completely combusted with excess air ratio which is determined by the temperature of flue gases at the turbine inlet. The analysis further includes variability of the molar heat capacities of air and flue gases with temperature and variability of their heat capacity ratios. The exergy destruction in turbine, compressor and combustion chamber and also total exergy efficiency of the cycle are considered in the analysis.