scholarly journals Thermal efficiency of the regenerative cycle of the Stirling engine scheme gamma

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
N. M. Sharpar ◽  
◽  
L. I. Zhmakin ◽  
Keyword(s):  
Energy Efficiency ◽  
Thermal Inertia ◽  
Stirling Engine ◽  
Working Fluid ◽  
Carnot Cycle ◽  
Energy Costs ◽  
Working Process ◽  
Hot Gas ◽  
Cold Area ◽  
Regenerative Cycle

The paper presents a theoretical model of the Stirling engine-gamma scheme, based on thermodynamic dependencies describing the working process taking into account the efficiency of the regenerator. The measurement of the gas pressure in the cycle, due to which its operation was carried out, is carried out by means of a plunger moving along the cylinder. Cooling in the working cylinder circuit is carried out at the expense of the environment. Due to the movement of the working fluid between the cylinders, there is an increase or decrease in pressure, which requires energy costs that affect the operation of the engine. An increase in the energy efficiency of the Stirling engine is achieved by introducing a regenerator into it, which helps to minimize heat losses. This device is located between the hot and cold cylinder, it is a cavity that contains a porous material that receives heat flowing with hot gas into the cold area, when it is moved back before entering the heater, the regenerator returns the stored heat. Due to the introduction of the regenerator in the model, the engine increases energy efficiency, and the efficiency of its cycle reaches the efficiency of the Carnot cycle. In this paper, the authors apply thermodynamic laws to represent the processes that underlie the functioning of the Stirling machine, not only in its cylinders, but also in the battery, the analysis of thermal inertia of which confirms the above study.

An Axisymmetric Computational Fluid Dynamics Approach to the Analysis of the Working Process of a Solar Stirling Engine

2005 ◽  
Vol 128 (1) ◽  
pp. 45-53 ◽  
Author(s):  
K. Mahkamov
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Stirling Engine ◽  
Gas Temperature ◽  
Working Process ◽  
Cfd Models ◽  
Pressure Distributions ◽  
Operational Characteristics ◽  
Computational Fluid Dynamics Cfd

The use of computational fluid dynamics (CFD) models significantly extends the capabilities for the detailed analysis of the complex heat transfer and gas dynamic processes that occur in the internal gas circuit of a Stirling engine by more accurately predicting the engine’s performance. This accurate data on operational characteristics of the engine can then contribute to more precise calculations of the dimensions of a parabolic concentrator in a dish/Stirling engine installation. In this paper a successful axisymmetric CFD simulation of a solar “V”-type Stirling engine is described for the first time. The standard κ-ε turbulence model, with a moving mesh to reflect the reciprocating motion of the pistons, has been employed for the analysis of the engine’s working process. The gas temperature and pressure distributions and velocity fields in the internal gas circuit of the machine have been obtained and the pressure-volume diagrams have been calculated. Comparison of the numerical results produced from the axisymmetric CFD simulation of the engine’s working process with those computed with the use of second-order mathematical analysis shows that there are considerable differences. In particular, analysis of the data obtained indicates that the gas temperature in the compression space depends on the location in the cylinder for the given moment in the cycle and it may differ substantially from being harmonic in time.

scholarly journals Mathematical model of the mechanism of the "alpha" type Stirling engine for operation in the timber industry complex

2020 ◽  
Vol 210 ◽  
pp. 08010
Author(s):  
Еvgenii Tihonov ◽  
Valentin Bazykin ◽  
Olga Gerasimova ◽  
Sergey Soloviev
Keyword(s):  
Model Simulation ◽  
Stirling Engine ◽  
Working Process ◽  
Timber Industry ◽  
Cyclic Flow ◽  
Piston Cylinder ◽  
Urgent Task ◽  
Effective Use ◽  
Alpha Type ◽  
Engine Type

This article discusses the multi-criteria parameterization of the crank-slider group of the Stirling engine type "alpha". The dependences of the displacement of the piston and the displacer are obtained, taking into account a number of variable geometric parameters. The resulting equation of movement of the piston from displacement of the propellant is composed of a crankshaft angle, which will allow to obtain a numerical model simulation of the crank-slider group that will significantly reduce the time of numerical calculations. The dependence of the torque on the crankshaft with known pressures on the piston and the displacer is obtained. This study will eventually allow us to determine the optimal parameters of the designed steering engine, depending on the power and operating temperatures. This will allow us to design an engine for use in the timber industry (use of logging and woodworking waste as fuel). Effective use for energy generation is an urgent task of the forest complex. Currently, obtained torque equation will allow us to study the working process of the engine when solving the gas-dynamic problem of cyclic flow of gas from the cavity of the piston cylinder to the cavity of the displacer cylinder and back.

Analysis of the Working Process and Mechanical Losses in a Stirling Engine for a Solar Power Unit

1999 ◽  
Vol 121 (2) ◽  
pp. 121-127 ◽  
Author(s):  
Kh. Kh. Makhkamov ◽  
D. B. Ingham
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Power Unit ◽  
Computational Simulation ◽  
Mass Conservation ◽  
Stirling Engine ◽  
Computational Results ◽  
Working Process ◽  
Euler’S Method ◽  
Governing System

In this paper a second level mathematical model for the computational simulation of the working process of a 1-kW Stirling engine has been used and the results obtained are presented. The internal circuit of the engine in the calculation scheme was divided into five chambers, namely, the expansion space, heater, regenerator, cooler and the compression space, and the governing system of ordinary differential equations for the energy and mass conservation were solved in each chamber by Euler’s method. In additional, mechanical losses in the construction of the engine have been determined and the computational results show that the mechanical losses for this particular design of the Stirling engine may be up to 50% of the indicated power of the engine.

Experimental Analysis of Micro-CHP Based on Biomass Direct-Fired Stirling Engine

2012 ◽  
Vol 151 ◽  
pp. 36-40
Author(s):  
Da Guo Ma ◽  
Xin Bo Jiang ◽  
Xu Zhang ◽  
Yan Ma
Keyword(s):  
Energy Use ◽  
Engine Speed ◽  
Stirling Engine ◽  
Biomass Energy ◽  
Working Process ◽  
Charge Voltage ◽  
Thermal Energy Conversion ◽  
Energy Conversion Process ◽  
Working Principle ◽  
Use Efficiency

The working principle of the micro-CHP based on biomass direct-fired Stirling engine and the thermal energy conversion process of the biomass direct-fired fuels were analyzed. On the basis of analysis, a 1kW β-type Stirling generator was designed and constructed for lab tests. Then, experiments were carried out to evaluate the effectiveness of the prototype. Through the analysis of experimental data and simulation, the change law of charge voltage, charge current with the engine speed and pressure, as well as the relation of heat and electricity, the power generation efficiency and the overall efficiency of the thermoelectric in the working process was obtained. The results showed that biomass energy use efficiency will be improved through the use of micro-CHP based on biomass direct-fired Stirling engine.

Sign in / Sign up

Export Citation Format

Share Document