Technical Laboratory

Moodle-Hyperlink - Technical Laboratory

BHKW

Within the scope of the specialist laboratory test
"Function and application possibilities of a gas engine driven combined heat and power unit (CHP)", knowledge about the basic function of a CHP unit, its application possibilities as well as its energetic investigation shall be imparted. To this end, experiments will be carried out on a mini cogeneration unit of the ecoPOWER 4.7 type and evaluated by the students. The CHP is to be placed in the overall context of the energy industry with the help of the basic knowledge acquired and evaluated from an economic and ecological point of view using two example objects. CHP is defined as the simultaneous extraction of mechanical, electrical and thermal useful energy from other forms of energy by means of a thermodynamic process in a technical plant. This process can be implemented both in large-scale power plants with thermal outputs of up to several hundred megawatts and in compact mini cogeneration units with a few kilowatts. The products after the energy conversion of the fuel in the technical plant are electricity and heat. A CHP plant works most efficiently if electricity and heat are used directly on site without large transmission paths, but the use of CHP depends on the heat requirement, since electricity can be transmitted more efficiently and cheaper than heat due to the existing infrastructure of the public electricity grid. Excess electricity fed into the grid is remunerated by the grid operator in accordance with the Combined Heat and Power Act (KWKG).



Figure 1: Examples for the energy balance of different plants


Fuel Cell


Within the framework of the laboratory test "Energy balance of a fuel cell system", the basic functions and application possibilities of different fuel cells are to be taught, with the focus on the polymer electrolyte membrane fuel cell (PEMFC). A controlled electrochemical reaction produces electricity and heat from hydrogen and oxygen. Thus fuel cells can be used in stationary, mobile and portable areas. Stationary, for example, they are suitable for the decentralized energy supply of a house. In the mobile sector, they can be used to drive cars or bicycles, and in the portable sector to power electrical appliances. In order to impart knowledge about the functionality and the system behaviour during operation, characteristic current-voltage curves are to be created and energy balances are to be carried out under different system loads. The required measured values will be determined at a PEMFC with a rated power of 40 watts and at a PEMFC with a rated power of 360 watts.



Figure 2: Functionality of a PEMFC