scholarly journals Method for calculating the power of a rotor-screw machines

2018 ◽  
Vol 226 ◽  
pp. 01007 ◽  
Author(s):  
Valeriy A. Lebedev ◽  
Georgy V. Serga ◽  
Irina V. Davydova ◽  
Tatiana V. Atoyan ◽  
Irina G. Koshlyakova ◽  
...  
Keyword(s):  
Economic Assessment ◽  
Technological Systems ◽  
Drive Power ◽  
Assessment Study ◽  
Optimal Power ◽  
Screw Machine ◽  
Working Medium ◽  
Screw Rotor ◽  
St3 Steel ◽  
Steel Balls

Features of parts machining in rotor-screw technological systems are presented. It is shown that the mass of the load, consisting of the processed parts and the granulated working medium, is located along the internal perimeter of the screw rotor asymmetrically to the axis of its rotation. In this regard, there are difficulties in designing the rotor-screw machines drive, and in the rationale for its optimal power. A technique is proposed for calculating the drive power of rotor-screw machines, which makes it possible to carry out a techno-economic assessment study of their applicability for finishing-hardening machining of parts in machinebuilding production. The technique is illustrated on the basis of justifying the drive power of a rotor-screw machine for hardening the details of St3 steel in a screw rotor mounted from 9 octahedra, steel balls are used as a working medium.

Technological scheme of fi nishing and strengthening of parts in screw working elements machines and rationale for their drive power

2020 ◽  
pp. 400-403
Author(s):  
M.M. Chaava ◽  
G.V. Serga ◽  
Al Obaydi Luai Mohammed Rajab
Keyword(s):  
Rotation Axis ◽  
Technological Scheme ◽  
Drive Power ◽  
Asymmetric Loading ◽  
Working Medium ◽  
Working Element ◽  
Screw Rotor ◽  
Screw Rotors ◽  
Tetrahedral Voids ◽  
Load Mass

Typical technological scheme of the machine for finishing and cleaning and strengthening treatment with working elements in the form of screw rotors mounted from tetrahedral voids is presented. Method for calculating of the drive of these machines is proposed, taking into account the load mass, the working element mass and the load mass located asymmetrically in the working element of the rotation axis, which allows you to calculate the power of the electric motors of machines for finishing, cleaning and strengthening treatment taking into account the actions of symmetrical and asymmetric loading processed parts and particles of the working medium relative to the rotation axis of the screw rotor.

scholarly journals Performance Analysis and Optimization for Irreversible Combined Carnot Heat Engine Working with Ideal Quantum Gases

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 536
Author(s):  
Lingen Chen ◽  
Zewei Meng ◽  
Yanlin Ge ◽  
Feng Wu
Keyword(s):  
Power Output ◽  
Thermal Efficiency ◽  
Combined Cycle ◽  
Quantum Gases ◽  
Carnot Cycle ◽  
Leakage Loss ◽  
Optimal Power ◽  
Heat Leakage ◽  
Working Medium ◽  
Ideal Quantum

An irreversible combined Carnot cycle model using ideal quantum gases as a working medium was studied by using finite-time thermodynamics. The combined cycle consisted of two Carnot sub-cycles in a cascade mode. Considering thermal resistance, internal irreversibility, and heat leakage losses, the power output and thermal efficiency of the irreversible combined Carnot cycle were derived by utilizing the quantum gas state equation. The temperature effect of the working medium on power output and thermal efficiency is analyzed by numerical method, the optimal relationship between power output and thermal efficiency is solved by the Euler-Lagrange equation, and the effects of different working mediums on the optimal power and thermal efficiency performance are also focused. The results show that there is a set of working medium temperatures that makes the power output of the combined cycle be maximum. When there is no heat leakage loss in the combined cycle, all the characteristic curves of optimal power versus thermal efficiency are parabolic-like ones, and the internal irreversibility makes both power output and efficiency decrease. When there is heat leakage loss in the combined cycle, all the characteristic curves of optimal power versus thermal efficiency are loop-shaped ones, and the heat leakage loss only affects the thermal efficiency of the combined Carnot cycle. Comparing the power output of combined heat engines with four types of working mediums, the two-stage combined Carnot cycle using ideal Fermi-Bose gas as working medium obtains the highest power output.

scholarly journals Optimization of the thermal circuit by introduction of the steam screw-rotor machine

2019 ◽  
Vol 21 (5) ◽  
pp. 14-21
Author(s):  
R. R. Rotach ◽  
Yu. V. Vankov ◽  
Sh. G. Ziganshin ◽  
I. V. Izmaylova
Keyword(s):  
Thermal Power ◽  
Payback Period ◽  
Electricity Production ◽  
Technical Solution ◽  
Thermal Circuit ◽  
Screw Machine ◽  
Equivalent Fuel ◽  
Calculation Results ◽  
Screw Rotor ◽  
Selection Of

The aim of the work is to increase the efficiency of the CHP by introducing a steam screw-rotor machine (SSRM) into the thermal circuit. It is proposed to exclude the passage of steam from the selection of the turbine through the pressure reduction and desuperheating station (PRDS) of own needs. Superheated steam is diverted to be sent to a steam screw-rotor machine installed parallel to the PRDS. This technical solution will allow to obtain steam used in low pressure deaerators, as well as electricity for own needs of the CHP. The article presents the operating parameters, as well as the calculation results of the backpressure turbine. A feasibility study was carried out for the introduction of SSRM into the plant’s thermal circuit: the equivalent fuel and electricity savings for own needs were calculated, as well as the payback period of the project for introducing a steam screw-rotor machine. In the course of the calculations, the following results were obtained: a decrease in the specific consumption of equivalent fuel for the production of 1 kWh of electricity – by 1,9 g; saving of equivalent fuel during the implementation of the SSRM will be 13 tons per year, which also entails a reduction in emissions into the environment; Electricity production for own needs is 8100 kWh, the payback period for the project to introduce a steam screw machine in the thermal circuit of a thermal power plant is 5 years.

Economic Assessment of ICAR-NRCSS Coriander Variety (ACr-1) using Economic Surplus Model

2021 ◽  
pp. 653-658
Keyword(s):  
Social Impact ◽  
Yield Loss ◽  
Economic Assessment ◽  
Social Benefit ◽  
Resistant Variety ◽  
Economic Surplus ◽  
Net Returns ◽  
Assessment Study ◽  
Stem Gall ◽  
The Impact

Coriander, the major seed spice is grown in the Rajasthan, suffers from various fungal diseases, of which the stem gall being the most destructive and versatile disease causing up to 50 percent yield loss. ICAR-NRCSS Ajmer released a stem gall resistant variety named Ajmer Coriander-1 (ACr-1). Economic Surplus Model was used to examine the economic impact of ACr-1 in Rajasthan. The study found that the ACr-1 variety developed by the ICAR-NRCSS performed well as the net social benefit was `11105.83 million with 15 percent adoption of the variety during six years (2013-14 to 2018-19). The impact assessment study of the stem gall resistant variety (ACr-1) released by ICAR-NRCSS has earned positive social impact, and net returns to the coriander farmers can be further increased with wider adoption of this variety.

Development and Optimization of Screw Machines With a Simulation Model—Part II: Thermodynamic Performance Simulation and Design Optimization

1997 ◽  
Vol 119 (3) ◽  
pp. 664-670 ◽  
Author(s):  
K. Hanjalic´ ◽  
N. Stosˇic´
Keyword(s):  
Fluid Flow ◽  
Control Volume ◽  
Performance Simulation ◽  
Design Procedures ◽  
Rotor Profile ◽  
Screw Machine ◽  
Twin Screw ◽  
Fluid Properties ◽  
Screw Rotor ◽  
Tip Radius

This paper presents a method for the design of twin screw compressors and expanders, which is based on a differential algorithm for defining the rotor profile and an analytical model of the fluid flow and thermodynamic processes within the machine. Part I of the paper presents a method for screw rotor profile generation which simplifies and improves design procedures. An example is given of its use in the development of a new “N” rotor profile, which is shown to be superior to other well-known types. Part II describes a numerical model of the thermodynamic and fluid flow processes within screw machines, which is valid for both the compressor and expander modes of operation. It includes the use of the equations of conservation of mass and energy applied to an instantaneous control volume of trapped fluid within the machine with allowance for fluid leakage, oil or other fluid injection, heat transfer, and the assumption of real fluid properties. By simultaneous solution of these equations, pressure-volume diagrams may be derived of the entire compression or expansions, process within the machine. The procedure has been developed over a period of fifteen years and validated with experimental results obtained from both reciprocating and screw compressors and screw expanders, some of which are included. The rotor profile generation processor, thermofluid solver and optimizer, together with preprocessing facilities for the input data and graphical post-processing and CAD interface, have been incorporated into a design package which provided a suitable tool for analysis and optimization of twin screw machine design. An example of its use is given in the optimization of the gate tip radius of a selected compressor design.

scholarly journals Main trends in intensification of rotor-screw processing of parts

2018 ◽  
Vol 226 ◽  
pp. 01008 ◽  
Author(s):  
Valeriy A. Lebedev ◽  
Georgy V. Serga ◽  
Irina V. Davydova ◽  
Tatiana V. Atoyan ◽  
Irina G. Koshlyakova ◽  
...  
Keyword(s):  
Structural Changes ◽  
Movement Speed ◽  
Processing Application ◽  
Screw Machine ◽  
Working Element ◽  
Productivity Increase ◽  
Screw Rotor ◽  
Production Organization ◽  
Screw Rotors

The ways of productivity increase in details finishing-strengthening processing executed in rotor-screw technological systems are presented. It is shown that the use of rotor-screw machines makes it possible to combine the parts machining using a vibrating field with a large amplitude of oscillations and their transportation in a streamlined form of production organization. Two main directions of rotor-helical processing stimulation are identified: on the basis of structural changes in the screw rotor, as the main working element of the rotor-screw machine and by equipping the screw rotor with activation elements of the process. The classification of screw rotors is presented, which allows purposeful search for the most effective designs of screw rotors and the mechanism is revealed of their influence on the process of parts finishing-hardening processing. Dependence is established for determining the longitudinal movement speed of the parts being processed in the screw rotor. The constructive-technological scheme of the rotor-screw machine is proposed, which allows increase of the productivity of the process and simplification of the design of machines for their implementation, by dismembering the complex screw propulsion of the load mass, which takes place in the screw rotors, into relatively simple in kinematic sense motions. The technological possibilities of rotor-screw processing application for finishing-strengthening operations are presented.

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