Temperature Differential Stirling Engine Research Articles

Workshop of assembling low temperature differential Stirling engine in which positioning of cylinder and flat-shaped cylinder head by pins

The Low temperature differential Stirling engine for a craft workshop was improved. Fine adjustment during assembly is not necessary. Here, the explanation for attendees of a 5-hour-course craft workshop is shown by some pictures.

Polyethylene bellows for model low temperature differential Stirling engine

Polyethylene bellows for model low temperature differential Stirling engine

An experimental study of a gamma-type MTD stirling engine

In this work, a prototype of a γ-type Moderate Temperature Differential (MDT) Stirling engine is manufactured, evaluated, and structurally optimized. An inexpensive mathematical evaluation is carried out based on the finite-dimension thermodynamics (FDT) approach. The optimum swept volume ratio, which contributes to the maximized work and efficiency, is achieved under various conditions based on the temperature difference of 450 K. A computer program is developed to evaluate the performance of the Stirling engine under the assumed working conditions. The swept volume ratio of the engine is found to be 3 for the temperature difference of 450 K. The engine dimensions are then adjusted to fulfil the computed swept volume ratio. The bore and stroke for piston are chosen as 63 mm and 40 mm, respectively. For the displacer, they are selected as 90 mm and 60 mm, respectively, based on the chosen swept volume ratio. Experiments are designed and carried out to verify the output power of the engine at various swept volume ratios, while the device is powered by a Liquefied Petroleum Gas (LPG) heater as simulator of solar energy under atmospheric pressure. The FDT results are shown to be in a very good agreement with the experimental outcomes, whereby the validity of the theoretical approach is confirmed. The findings of this research can be useful as guideline for optimization of MTD Stirling engines.

Dynamic analysis and demonstration of flywheel-less low temperature differential Stirling engine using bellows instead of power piston

Dynamic analysis and demonstration of flywheel-less low temperature differential Stirling engine using bellows instead of power piston

Optimization of Low Temperature Differential Stirling Engine Regenerator Design

Optimization of Low Temperature Differential Stirling Engine Regenerator Design

Theoretical Analysis of Hybrid Dense-Array Concentrator Photovoltaic and Stirling Engine System

Abstract In this paper, we analyse the performance of newly proposed hybrid dense-array concentrator photovoltaic (CPV) and gamma type low temperature differential (LTD) Stirling engine. Schmidt Analysis was applied to compute the performance of LTD Stirling engine while computational fluid dynamic was employed to simulate the heat transfer in the CPV receiver. The simulated result was subsequently used to determine the power conversion efficiency of the hybrid system. Three major parameters have been considered to optimize the overall system performance including water inlet temperature, water flow rate, and CPV surface temperature. In our theoretical analysis, the highest efficiency of the hybrid system ranging 37.8 - 38.0 % can be achieved at water inlet temperature of 90°C. It has shown significant improvement by producing 10.1 -10.7 % extra energy as compared to the efficiency of CPV system without waste heat recovery.

Development of Stirling Pump mechanism for Irrigation in remote rural farms

Inadequate supply of safe water, the requirement of food exports, Low GDP creates a scenario where 26% of the population in the Sub-Saharan Africa suffer from food insecurity. Cultivation of food locally is necessary to drive the cost of food down. This can be done using the abundant groundwater source in the region, however, the energy cost of harvesting the water supply is very high and hence not presently utilised. While solar PV technology is readily available, PV solutions are much too expensive for small scale rural farmers. This research aims at developing a solar thermal powered Stirling pump that can be produced locally, using local resources to reduce irrigation costs and provide income, food and energy security in the region, by promoting independent farming through small-scale farms. In order to develop the Stirling pump, a Low Temperature Differential (LTD) Stirling engine has been modelled in 3D, simulated and investigated with the help of Computational Fluid Dynamics with ANSYS 16.1 software. The Analysis is aimed at obtaining a true representation of the pressure, temperature and compression ratio that dictate the functioning of a Gamma type Stirling engine. This model developed can then be modified and improved upon to further boost the performance of the Stirling Engine to be integrated with a water pumping system to extract ground water for irrigation purposes.

Workshop of assembling low temperature differential Stirling engine designed for craft workshop for 5 person who want to see the inside

Workshop of assembling low temperature differential Stirling engine designed for craft workshop for 5 person who want to see the inside

Dynamic analysis of low temperature differential Stirling engine using bellows instead of piston

Dynamic analysis of low temperature differential Stirling engine using bellows instead of piston

Proof of concept to recover thermal wastes from aluminum electrolysis cells using Stirling engines

The production of aluminum is a low energy-efficient industrial process. In fact, almost half of its energy demand is lost under the form of heat along the production line. For this reason, aluminum producers are interested in improving energy efficiency of their smelters by recovering the thermal losses. It is well known that a significant loss of energy occurs across the sidewalls of the electrolysis cells. This paper proposes a proof of concepts where the sidewall thermal wastes are used to drive Low Temperature Differential (LTD) Stirling engines. To estimate the losses, a heat transfer study is implemented; heat conduction coupled with mixed convection and radiation is evaluated by using the OpenFOAM Computational Fluid Dynamic (CFD) software. Then, a parametric study is performed to analyse cell working conditions under which thermal wastes could be recovered. The heat flux and the temperature of the thermal wastes are used to judge the utilization of possible Stirling engine technologies. Two scenarios are studied: (i) a plane heat collector coupled to the radiative sidewall and (ii) a plane heat collector in direct thermal contact with the cell sidewall. It is demonstrated that the recovery of the wastes by radiation is technically feasible and it does not threaten the safety of the smelter; furthermore, the losses can power some Stirling engines given in the open literature. Therefore, the recovery of the radiative wastes and the further conversion by means of the Stirling engine is an interesting solution to improve the aluminium smelter energy efficiency.

Design and Fabrication of Low Temperature Differential Stirling Engine - Gamma Type

Design and Fabrication of Low Temperature Differential Stirling Engine - Gamma Type

An engine speed estimation of a low temperature differential Stirling engine using Microsoft Excel

An engine speed estimation of a low temperature differential Stirling engine using Microsoft Excel

Parts designs of low temperature differential Stirling engines relieving the assembly of fine adjustments

Parts designs of low temperature differential Stirling engines relieving the assembly of fine adjustments

Workshop of assembling low temperature differential Stirling engine for 5 person who want to see the inside

Workshop of assembling low temperature differential Stirling engine for 5 person who want to see the inside

Design of stirling engine operating at low temperature difference

There are many sources of free energy available in the form of heat that is often simply wasted. The aim of this paper is to design and build a low temperature differential Stirling engine that would be powered exclusively from heat sources such as waste hot water or focused solar rays. A prototype is limited to a low temperature differential modification because of a choice of ABSplus plastic as a construction material for its key parts. The paper is divided into two parts. The first part covers a brief history of Stirling engine and its applications nowadays. Moreover, it describes basic principles of its operation that are supplemented by thermodynamic relations. Furthermore, an analysis of applied Fused Deposition Modelling has been done since the parts with more complex geometry had been manufactured using this additive technology. The second (experimental) part covers 4 essential steps of a rapid prototyping method - Computer Aided Design of the 3D model of Stirling engine using parametric modeller Autodesk Inventor, production of its components using 3D printer uPrint, assembly and final testing. Special attention was devoted to last two steps of the process since the surfaces of the printed parts were sandpapered and sprayed. Parts, where an ABS plus plastic would have impeded the correct function, had been manufactured from aluminium and brass by cutting operations. Remaining parts had been bought in a hardware store as it would be uneconomical and unreasonable to manufacture them. Last two chapters of the paper describe final testing, mention the problems that appeared during its production and propose new approaches that could be used in the future to improve the project.

Workshop of assembling low temperature differential Stirling engine version 2017

Workshop of assembling low temperature differential Stirling engine version 2017

Operation of Low temperature differential Stirling engine competition and presentations

Operation of Low temperature differential Stirling engine competition and presentations

A low temperature differential Stirling engine design relieving the assembly of a fine adjustment

A low temperature differential Stirling engine design relieving the assembly of a fine adjustment

Low temperature differential Stirling engines using displacers moving intermittently

Low temperature differential Stirling engines using displacers moving intermittently

Effect of geometry and speed on the temperatures estimated by CFD for an isothermal model of a gamma configuration low temperature differential Stirling engine with Flat-shaped heat exchangers

In the temperature distribution in a hot-side displacer chamber of a low temperature differential Stirling engine, a relation between the inlet temperature, average temperature and heat exchanger temperature is calculated by CFD and is expressed by the ratio of temperatures. The parameters of the CFD are the inlet velocity; the sizes of the inlet, heat exchanger and displacer; the positions of the inlet, heat exchanger and displacer chamber wall; and the temperatures of the inlet and heat exchanger. The calculation result and the estimated regenerator efficiency produce the temperature difference in the working fluid, which can be utilized for isothermal model analysis. In the Schmidt cycle, only a phase angle and the dimensionless value introduced here dominate the shape of the P-V diagram. The maximum fluctuation of the ensemble averaged working fluid temperatures (MFEAWFTs) is utilized to evaluate a P-V diagram. When the analyses are compared with experimental results, estimated MFEAWFTs are approximately 80% of the experimental results. In comparing the calculation results, a higher engine speed causes a lower average temperature on the hot side of a displacer chamber and the larger indicated power. A wider inlet reduces the difference between inlet temperature and average temperature. The longer stroke of displacer motion makes the indicated work larger to some extent.