Search results
Results From The WOW.Com Content Network
A Stirling engine uses a single-phase working fluid that maintains an internal pressure close to the design pressure, and thus for a properly designed system the risk of explosion is low. In comparison, a steam engine uses a two-phase gas/liquid working fluid, so a faulty overpressure relief valve can cause an explosion.
The cycle is defined as a closed regenerative cycle with a gaseous working fluid. "Closed cycle" means the working fluid is permanently contained within the thermodynamic system. This also categorizes the engine device as an external heat engine.
The Beale number can be defined in terms of a Stirling engine's operating parameters: = where: B n is the Beale number; Wo is the power output of the engine ; P is the mean average gas pressure or (MPa, if volume is in cm 3) V is swept volume of the power piston (m 3, or cm 3, if pressure is in MPa)
A Fluidyne engine is an alpha or gamma type Stirling engine with one or more liquid pistons. It contains a working gas (often air), and either two liquid pistons or one liquid piston and a displacer. [1] The engine was invented in 1969. [2] The engine was patented in 1973 by the United Kingdom Atomic Energy Authority. [3] [2]
The engine has near isothermal cylinders because 1) the heater area covers the entire cylinder end, 2) it is a short stroke device, with wide shallow cylinders, yielding a high surface area to volume ratio, 3) the average thickness of the gas space is about 0.1 cm, and 4) the working fluid is Helium, a gas having good thermal properties for Stirling engines.
In closed cycle, the lower pressure can be significantly above ambient pressure, and He or H 2 working gas can be used. Because of the higher pressure difference between the upward and downward movement of the work-piston, specific output can be greater than of a valveless Stirling engine. The added cost is the valve. Ericsson's engine also ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The choice of working fluids is known to have a significant impact on the thermodynamic as well as economic performance of the cycle. A suitable fluid must exhibit favorable physical, chemical, environmental, safety and economic properties such as low specific volume (high density), viscosity, toxicity, flammability, ozone depletion potential (ODP), global warming potential (GWP) and cost, as ...