What is closed cycle MHD system?
A closed cycle MHD system using helium or argon gas seeded with Cesium is shown in Figure. In this system, helium gas seeded with Cesium is heated to a very high temperature in a nuclear reactor. The hot helium gas is passed through a nozzle to increase its velocity and then supplied to MHD duct to produce DC power.
What is MHD generator explain its working principle?
The working principle of MHD generator is based on Faraday’s Law. It states that when a conductor is moved in a magnetic field an EMF is induced in the conductor. These ions are the electrical conductors. After that, ionized gases are moved in a duct known as the MHD duct at very high velocity.
What are the working fluids in open cycle and closed cycle MHD systems?
The operation of MHD generators directly on combustion products is an open cycle system using air as working fluid. In closed cycle systems gases used on the working fluid are helium or argon.
What are the different types of MHD generators?
Basically, an MHD generator is a device for directly converting thermal energy into electricity. There are three types of MHD cycle: open, closed and liquid-metal. Figure 1.
What is the difference between open cycle and closed cycle OTEC?
There are two principle options, an open cycle plant or a closed cycle plant. Hybrids of the two have also been proposed. A closed cycle OTEC plant employs a thermodynamic fluid such as ammonia or a refrigerant like freon. In an open cycle OTEC system the seawater itself is used to provide the thermodynamic fluid.
What are the advantages of MHD?
Advantages of MHD Generation A high conversion efficiency of around 50%. A large amount of power is generated. Better utilisation of fuel. Since it has no moving parts, so it is more reliable.
How are MHD systems classified?
For MHD, thermal energy is directly converted to electrical energy, hence know as direct energy conversion system. The MHD power plants can be classified as open and closed cycle based on the nature of processing of the working fluid.
Which type of gas is used in MHD generator?
An MHD generator, like a conventional generator, relies on moving a conductor through a magnetic field to generate electric current. The MHD generator uses hot conductive ionized gas (a plasma) as the moving conductor.
What is the function of nozzle in MHD generator?
MHD system : The expansion nozzle reduces the gas pressure and consequently increases the plasma speed (Bernoulli’s Law) through the generator duct to increase the power output (See Power below). Unfortunately, at the same time, the pressure drop causes the plasma temperature to fall (Gay-Lussac’s) must be found.
What is the function of seeding used in MHD?
What is seeding in MHD generation? Seeding is a process of injecting a seeding material like potassium carbonate or cesium into the plasma/fluid to increase the electrical conductivity.
Who proposed closed cycle?
Explanation: The closed cycle approach was first proposed by Bajrot in 1926, but the most recent design was by Anderson in 1960s. The closed cycle is sometimes referred to as Anderson cycle. The Anderson cycle chose Propane as working fluid. Explanation: The working fluid chosen by Anderson OTEC cycle is propane.
