Search results
Results from the WOW.Com Content Network
Diagram of an open cycle OTEC plant. Open-cycle OTEC uses warm surface water directly to make electricity. The warm seawater is first pumped into a low-pressure container, which causes it to boil. In some schemes, the expanding vapor drives a low-pressure turbine attached to an electrical generator.
If at every point in the cycle the system is in thermodynamic equilibrium, the cycle is reversible. Whether carried out reversible or irreversibly, the net entropy change of the system is zero, as entropy is a state function. During a closed cycle, the system returns to its original thermodynamic state of temperature and pressure.
The three diagrams are constructed from the P–alpha diagram by using appropriate coordinate transformations. Not a thermodynamic diagram in a strict sense, since it does not display the energy–area equivalence, is the Stüve diagram; But due to its simpler construction it is preferred in education. [citation needed]
The gas-generator cycle, also called open cycle, is one of the most commonly used power cycles in bipropellant liquid rocket engines. Propellant is burned in a gas generator (or "preburner") and the resulting hot gas is used to power the propellant pumps before being exhausted overboard and lost.
A heat engine is a system that transfers thermal energy to do mechanical or electrical work. [1] [2] While originally conceived in the context of mechanical energy, the concept of the heat engine has been applied to various other kinds of energy, particularly electrical, since at least the late 19th century.
The polar cell is a simple system with strong convection drivers. Though cool and dry relative to equatorial air, the air masses at the 60th parallel are still sufficiently warm and moist to undergo convection and drive a thermal loop. At the 60th parallel, the air rises to the tropopause (about 8 km at this latitude) and moves poleward.
Working fluids are often categorized on the basis of the shape of their T–s diagram. An isentropic process is depicted as a vertical line on a T–s diagram, whereas an isothermal process is a horizontal line. [2] Example T–s diagram for a thermodynamic cycle taking place between a hot reservoir (T H) and a cold reservoir (T C).
These engines may be based on a number of thermodynamic cycles encompassing both open cycle devices such as those of Sir George Cayley [3] and John Ericsson [4] and the closed cycle engine of Robert Stirling. [5] Hot air engines are distinct from the better known internal combustion based engine and steam engine.