Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Appraisal of temperature ranges and regenerator efficiency over Stirling Engines with mass transfer
Submission Author:
Fernanda Graeff Silverio , PR
Co-Authors:
Fernanda Graeff Silverio, Luís Mauro Moura, Stephan Hennings Och
Presenter: Fernanda Graeff Silverio
doi://10.26678/ABCM.ENCIT2022.CIT22-0028
Abstract
A world with growing population and limited natural resources requires innovative and smart solutions for energy management. Stirling engines have gained focus as an energy sustainable alternative due to its ability to convert heat from an external source into mechanical or electrical energy. The high theoretical engine efficiency of Stirling cycle can be compromised depending on the temperatures of the hot and cold sources, operating fluid, design dimensioning and regenerator efficiency. Low temperature ranges broaden the application of the Stirling engine, such as solar-powered Stirling engines and are on focus for different optimization problems and models evaluation. On the other hand, Stirling engines operating in high temperature ranges may be an opportunity to recover wasted heat with a low emission solution. On this article it is presented an evaluation of the temperatures of the cold and hot reservoir applied on the Stirling cycle based on a differential cycle, and its effect on the total work and thermal efficiency of the engine. It is also evaluated how the regenerator can affect the performance of the proposed system. Based on the patented differential cycle and its one-dimensional model it is proposed a mathematical appraisal whose objective is perceive the response of the model to distinct temperature of external sources. System considers two β-type Stirling engines operating in a steady state point, simultaneously, and lacked by two thermodynamic phases among each other. It is also considered to have the mass transfer already stabilized. The dimensioning of the clearance volume of the engine is one the leading input parameters that allow the differential cycle to operate with lower temperature sources. It also directly affects the total work and efficiency generated by the model, and the initial charge mass of working fluid has the potential of increasing the work produced, even though not modifying the thermal efficiency of the cycle. The regenerator efficiency can increase the thermal efficiency, without influencing the total positive work out of the system.
Keywords
Stirling engine, Heat transfer, Thermal Efficiency
