scholarly journals Design features of a high-vacuum steam jet pump and some results of its tests

2021 ◽  
Vol 2119 (1) ◽  
pp. 012167
Author(s):  
I V Petrova ◽  
V I Ermolov ◽  
A K Rebrov
Keyword(s):  
Stainless Steel ◽  
Saturated Vapor ◽  
High Vacuum ◽  
Working Fluid ◽  
Steel Shell ◽  
Original Design ◽  
Jet Pump ◽  
Heating Cable ◽  
Homogeneous Chemical ◽  
Made In

Abstract This paper presents an original design of a high-vacuum steam jet pump in which a heater made of a heating cable is immersed in a working fluid located in a stainless steel boiler. At the same time, the boiler itself is vacuum isolated from the pump housing. There is also a heater made of a heating cable in a stainless steel shell, made in the form of a spiral and immersed in a working fluid. Such an arrangement of the heater is possible only when a liquid with a homogeneous chemical composition and a low saturated vapor pressure is used as a working fluid in high-vacuum pumps.

Examination of Thermal and Electrical Performance of Cassegrain Concentrator System

2019 ◽  
Vol 8 (6S2) ◽  
pp. 96-98
Keyword(s):  
Stainless Steel ◽  
Great Degree ◽  
Electrical Performance ◽  
Personal Satisfaction ◽  
The Sun ◽  
Supporting Structure ◽  
Apex Point ◽  
Control Water ◽  
Working Liquid ◽  
Made In

The sun oriented power (SP) is a one of a kind renewable vitality innovation. SP frameworks can give control, water warming and water decontamination in one unit. This innovation will be to a great degree accommodating in enhancing the personal satisfaction for some individuals around the globe who do not have the vitality expected to carry on with a sound life. A financial allegorical dish sort Cassegrain concentrating framework was created at the foundation of Energy Studies, Anna University Chennai. An old microwave media transmission reception apparatus having a paraboloidal shape made in aluminum frames an essential reflector which guarantees effortlessness of generation and operation. The essential concentrator was settled with mirror cleaned stainless steel with reasonable cement .The optional concentrator is inward mirror .Suitable supporting structure was developed for supporting the cassegrain concentrator. Double hub following framework is mounted for adjusting the concentrator to azimuth and apex point by utilizing DC engine and direct actuator individually. Water goes about as working liquid to expel warm from .The tank is protected with thermocol material upheld with wooden structure on all sides to maintain a strategic distance from convection misfortunes. The material Cost for the framework was Rs 15000

scholarly journals Experimental Study on Thermal Performance of a Loop Heat Pipe with Different Working Wick Materials

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2453
Author(s):  
Kyaw Zin Htoo ◽  
Phuoc Hien Huynh ◽  
Keishi Kariya ◽  
Akio Miyara
Keyword(s):  
Stainless Steel ◽  
Heat Pipes ◽  
Working Fluid ◽  
Stable Operation ◽  
Loop Heat Pipe ◽  
Heater Surface ◽  
Loop Heat Pipes ◽  
Limited Temperature ◽  
Sintered Stainless Steel ◽  
Continuous Heat

In loop heat pipes (LHPs), wick materials and their structures are important in achieving continuous heat transfer with a favorable distribution of the working fluid. This article introduces the characteristics of loop heat pipes with different wicks: (i) sintered stainless steel and (ii) ceramic. The evaporator has a flat-rectangular assembly under gravity-assisted conditions. Water was used as a working fluid, and the performance of the LHP was analyzed in terms of temperatures at different locations of the LHP and thermal resistance. As to the results, a stable operation can be maintained in the range of 50 to 520 W for the LHP with the stainless-steel wick, matching the desired limited temperature for electronics of 85 °C at the heater surface at 350 W (129.6 kW·m−2). Results using the ceramic wick showed that a heater surface temperature of below 85 °C could be obtained when operating at 54 W (20 kW·m−2).

Recent progress in the freeze-etching technique

1971 ◽  
Vol 261 (837) ◽  
pp. 121-131 ◽  
Keyword(s):  
High Vacuum ◽  
Molecular Size ◽  
Etching Technique ◽  
Structural Distortions ◽  
Shadow Casting ◽  
Structural Details ◽  
Freeze Etching ◽  
The One ◽  
Insight Into ◽  
Made In

The freeze-etching technique must be improved if structures at the molecular size level are to be seen. The limitations of the technique are discussed here together with the progress made in alleviating them. The vitrification of living specimens is limited by the fact that very high freezing rates are needed. The critical freezing rate can be lowered on the one hand by the introduction of antifreeze agents, on the other hand by the application of high hydrostatic pressure. The fracture process may cause structural distortions in the fracture face of the frozen specimen. The ‘double-replica’ method allows one to evaluate such artefacts and provides an insight into the way that membranes split. During etching there exists the danger of contaminating the fracture faces with condensable gases. Because of specimen temperatures below —110 °C, special care has to be taken in eliminating water vapour from the high vacuum. An improvement in coating freeze-etched specimens has resulted from the application of electron guns for evaporation of the highest melting-point metals. If heat transfer from gun to specimen is reduced to a minimum, Pt, Ir, Ta, W and C can be used for shadow casting. Best results are obtained with Pt-C and Ta-W . With the help of decoration effects Pt-C shadow castings give the most information about the fine structural details of the specimen.

Comparative Study on Remaining Life Assessment of a Pressure Vessel, Working in Severe Conditions, Based on Results of Metallographic Replicas and Creep Tests

2021 ◽  
Vol 1164 ◽  
pp. 67-75
Author(s):  
Iuliana Duma ◽  
Alin Constantin Murariu ◽  
Aurel Valentin Bîrdeanu ◽  
Radu Nicolae Popescu
Keyword(s):  
Stainless Steel ◽  
Life Assessment ◽  
Petrochemical Plant ◽  
Remaining Life ◽  
Creep Tests ◽  
Experimental Creep ◽  
Asme Code ◽  
Remaining Life Assessment ◽  
Service Duration ◽  
Made In

The paper presents and compares the results on the reliability and remaining life assessment of a reactor (coxing box) from a petrochemical plant. The reactor shell is made of 16Mo5 (W1.5423) steel, with a thickness of 25 mm, plated with 3 mm thick X6CrAl13 (W1.4002) stainless steel. The assessment was made in two steps. For preliminary remnant life assessment, specifications of section VII of the ASME code was used followed by iRiS‑Thermo expert system. Further, experimental creep and metallographic replica analysis were performed. Results comparison of the two methods applied revealed a reduction of the preliminary estimated remaining live obtained using metallographic replica analysis. Based on the results obtained, the possibility to extend the service duration of the coxing box in the safety condition, using current process parameters, with of 20.000 hours was highlighted.

Preliminary Investigation of an Up-Scaled Gamma-Type Stirling Engine for Power Production

2015 ◽  
Vol 786 ◽  
pp. 220-225 ◽  
Author(s):  
M.F. Hamid ◽  
Mohamad Yusof ◽  
M.K. Abdullah ◽  
Z.A. Zainal ◽  
M.A. Miskam
Keyword(s):  
Stainless Steel ◽  
Heat Source ◽  
Material Selection ◽  
Power Production ◽  
Stirling Engine ◽  
Load Test ◽  
Working Fluid ◽  
Temperature Differential ◽  
Stainless Steel Mesh ◽  
Steel Mesh

This paper presents the development of Gamma-type Stirling engine for High Temperature Differential (HTD) and self-pressurized mode of operation. The engine is the up-scaled version from the Low Temperature Differential (LTD) miniaturized gamma-type Stirling engine. The test engine is featured with 85cc power piston and 4357cc displacer piston swept volumes, respectively. The characterization of few critical engine parameters and components that includes heater head section, cooler section, displacer and power pistons material selection and heat source system had been conducted. Air is used as a working fluid and Liquefied Petroleum Gas (LPG) is utilized as the heat source in order to cater for the heater temperature up to 1000°C. The workability test of the engine revealed that the lightweight in mass of the displacer piston and the auxiliary cooling effect at the cooler section had contributed to a significant improvement on the engine rotational motion. The static load test determined that the engine is capable of producing the friction power of 1.2W for stainless steel mesh wire displacer and 0.3W for polystyrene displacer. Based on Beale formula, the estimated power of 4W can be produced by the engine using stainless steel mesh wire displacer and 2.4W of power using polystyrene displacer. Good agreement has been shown, where the potential net power production of 3.8W and 2.1 W for stainless mesh wire displacer and polystyrene displacer, respectively. Further investigation is needed to improve the heat regeneration in between hot and cold sections of the engine to realize the sustainable performance of the engine at higher range of temperature difference and output power.

Description of an Operating Closed Cycle: Helium Gas Turbine

1963 ◽  
Author(s):  
James K. La Fleur
Keyword(s):  
Gas Turbine ◽  
Working Fluid ◽  
Refrigeration Cycle ◽  
Preliminary Design ◽  
Closed Cycle ◽  
Helium Gas ◽  
Compressor Inlet ◽  
Last Stage ◽  
Low Temperature Refrigeration ◽  
Made In

In May of 1960 La Fleur Enterprises, later to become The La Fleur Corporation, undertook the design of a closed-cycle gas turbine utilizing helium as a working fluid. The useful output of this machine was to be in the form of a stream of helium bled from the last stage of the compressor. This stream was to be used in a low-temperature refrigeration cycle (not described in this paper) and would be returned to the compressor inlet at approximately ambient temperature and at compressor-inlet pressure. The design of this machine was completed by the end of 1960 and construction was initiated immediately. The unit was completed and initial tests were made in the Spring of 1962. This paper covers the design philosophy as it affected the conceptual and preliminary design phases of the project and describes briefly the design of the various components. Photographs of these components and a flow schematic are included.

Modification of Energy Equation for Homogeneous Cavitation Simulation With Thermodynamic Effect

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Anh Dinh Le ◽  
Junosuke Okajima ◽  
Yuka Iga
Keyword(s):  
Thermodynamic Model ◽  
Saturated Vapor ◽  
Homogeneous Model ◽  
Industrial Applications ◽  
Working Fluid ◽  
Suppression Effect ◽  
Evaporation And Condensation ◽  
Thermodynamic Effect ◽  
Cavitation Region ◽  
Cryogenic Liquids

In industrial applications, cryogenic liquids are sometimes used as the working fluid of fluid machineries. In those fluids, the thermodynamic suppression effect of cavitation, which is normally ignored in water at room temperature, becomes obvious. When evaporation occurs in the cavitation region, the heat is supplied from the surrounding liquid. Hence, the liquid temperature is decreased, and cavitation is suppressed due to the decrease in saturated vapor pressure. Therefore, the performance of the fluid machinery can be improved. Computational fluid dynamics, which involves the use of a homogeneous model coupled with a thermal transport equation, is a powerful tool for the prediction of cavitation under thermodynamic effects. In this study, a thermodynamic model for a homogeneous model is introduced. In this model, the source term related to the latent heat of phase change appears explicitly, and the degree of heat transfer rate for evaporation and condensation can be adjusted separately to suit the homogeneous model. Our simplified thermodynamic model coupled with the Merkle cavitation model was validated for cryogenic cavitation on a two-dimensional (2D) quarter hydrofoil. The results obtained during the validation showed good agreement (in both pressure and temperature profiles) with the experimental data and were better than existing numerical results obtained by other researchers.

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