China
Africa
Explore chapters and articles related to this topic
Renewable Energy
Published in Stephen A. Roosa, Steve Doty, Wayne C. Turner, Energy Management Handbook, 2020
Gabriel Caunt, Simon E. Baker, Stephen A. Roosa
Dish-engine technology uses a parabolic dish reflector to concentrate direct normal radiation onto a receiver adjoined to a power conversion unit. Figure 16-47 gives a schematic of a dish-type concentrator coupled to a Stirling engine. Because of the small focal region, dish-engine systems track the sun on two axes—azimuth-elevation and polar. Most concentrators approximate the ideal shape with multiple spherically-shaped mirrors supported with a truss structure. Due to a short focal length and the need to pin-point solar rays at the receiver, dish-type systems require robust support structures to prevent efficiency losses from wind vibrations. A receiver transfers solar energy to a high-pressure working gas, usually helium or hydrogen. Stirling engines convert heat to mechanical power in basically the same manner as conventional engines, except the heat is impressed from the outside of the engine. Expansion and contraction of the solar-heated working gas drives a set of pistons and a crankshaft to produce power.
Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
Dish-Stirling systems track the sun and focus solar energy into a cavity receiver where it is absorbed and transferred to a heat engine/generator. Figure 67.3 is a picture of a Dish-Stirling system. Although a Brayton engine has been tested on a dish and some companies are considering adapting microturbine technology to dish engine systems, kinematic Stirling engines are currently being used in all four Dish-Stirling systems under development today. Stirling engines are preferred for these systems because of their high efficiencies (thermal-to-mechanical efficiencies in excess of 40% have been reported), high power density (40 to 70kW/liter for solar engines), and their potential for long-term, low-maintenance
Internal Combustion Engines
Published in Mehrdad Ehsani, Yimin Gao, Ali Emadi, and Fuel Cell Vehicles, 2017
Mehrdad Ehsani, Yimin Gao, Ali Emadi
The Stirling engine works based on the Stirling thermodynamic cycle. The ideal Stirling cycle is illustrated in Figure 3.17,5, 6 which consists of a cylinder containing two opposed pistons, with a regenerator between the pistons. The regenerator, a thermodynamic sponge, is usually a matrix of finely divided metal in the form of wires or strips. One of the two volumes between the regenerator and the pistons is the expansion space, in which high temperature, Tmax, is maintained by a heat source surrounding it. The other volume is the compression space, in which low temperature, Tmin, is maintained by the heat sink surrounding it. Therefore, there is a temperature gradient ( Tmax − Tmin ) across the transverse faces of the regenerator. It is usually assumed that there is no thermal conduction in the longitudinal direction.
A practical approach-based technical review on effective utilization of exhaust waste heat from combustion engines
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Rajesh Ravi, Oumaima Douadi, Manoranjitham Ezhilchandran, Mustapha Faqir, Elhachmi Essadiqi, Merouan Belkasmi, Shivaprasad K. Vijayalakshmi
Stirling engines work on a regenerative thermodynamic cycle known as “the Stirling cycle.” Unlike the ICEs, the Stirling engines lack associated valves and do not contain any intake or exhaust gases (Mohd Noor et al. 2015). This characteristic helps in preventing pollution. The engine’s air is contained within itself, whereas the heat energy is converted into mechanical energy by alternate pushing of the air from cold side of the engine to the hot side (Zafer and Selenay Önal 2018). Figure 9 depicts a Stirling engine coupled with a diesel engine to recover the waste heat energy. Even small temperature differences have the ability to power a Stirling engine by a few degrees. The Stirling engines are utilized in a variety of applications, particularly when a requirement exists for a large heat source and a noise-free motor (Mahmoudzadeh Andwari et al. 2017).
Numerical and experimental investigation on the drive mechanisms of Alfa type Stirling engines
Published in International Journal of Sustainable Energy, 2022
Energy-driven consumption of fossil fuels increases the number of carbon emissions, disrupts the world’s carbon cycle and leads to global warming and climate change. The Stirling engine can be a correct solution for the above problems. Since, the Stirling engine which is a prime mover device in external combustion engines; uses alternative heat sources such as waste heat and renewable energy sources; geothermal, temperature differences in the oceans, biomass and solar energy to produce cleaner power. Increasing the energy cost, environmental noise pollution and global warming have led to more studies on clean and efficient power generation engines such as Stirling engines. The efficiency of the Stirling engines can be improved further by increasing their capability on using waste heat and renewable energy sources.
Thermodynamic analysis of a gamma-type stirling engine driven by Scotch Yoke mechanism
Published in International Journal of Green Energy, 2021
Stirling engines are classified according to the positions of displacer and power piston. Based on this, there are three types of Stirling engines: alpha, beta, and gamma. The beta-type Stirling engine is equipped with a displacer and power pistons in a single cylinder (Abuelyamen et al. 2017). In alpha-type and gamma-type Stirling engines, the displacer and the power pistons are located in two separate cylinders. In alpha-type Stirling engine, hot end of displacer cylinder is connected to the power cylinder by means of a regenerator between them (Altın et al. 2018; Ipci and Karabulut 2018). In gamma-type Stirling engine, cold end of displacer is connected to power cylinder with a connecting element and hot end of displacer is connected to cold end of displacer with a regenerator (Cınar and Karabulut 2005). However, Stirling engines operates with a closed regenerative thermodynamic cycle regardless of cylinder configuration. Closed cycle attribution allows using miscellaneous working fluids. As working fluid, Stirling engines use air, helium, nitrogen, hydrogen, or other compressible fluids with higher heat transfer capabilities (Cheng and Chen 2017). Hydrogen and Helium has an advantage from the other compressible fluid because of its high heat transfer properties.