Vattenfall's Cogeneration Power Plant Reuter West
The cogeneration power plant “Reuter West” was erected as a base load power plant in the vicinity of the existing “Reuter” plant. The two hard coal fired 300 MW units D and E were commissioned in 1987 and 1989. Today the cogeneration units supplying electricity and thermal energy are operated by Vattenfall Europe GmbH.
The heart of each power plant is the boiler where the sun energy captured in form of hard coal will be released and converted into thermal energy. Modern multi stage burners combust the pulverized coal supported by primary, secondary and tertiary air. The aim of these different air flows is the complete and environmental friendly combustion which will cause high efficiency and low NOx emissions. Thus air staging must be precisely measured and controlled. Conventionally these flows have been measured with differential pressure devices so as in power plant “Reuter West”. A dp-flowmeter uses the physical effect found by Bernoulli, that with an increasing flow velocity of a fluid, the differential pressure over a flow restriction will increase by the power of two. Bernoulli’s law is independent of the primary element used generating the pressure drop. In boilers usually venturi nozzles are used as primary element. These flowmeter types not only have advantages. Pressure ports are required to transmit the process pressure to the dp transmitter. The differential pressure is also depending on the fluid density and viscosity influenced e.g. by gas moisture, particle content or temperature. Due to the quadratic pressure to flow dependence the turndown ratio of dp flowmeters is very limited. Finally dp flowmeters in such dusty environment have to be purged regularly. Intensive maintenance and drift caused the biggest headaches for the operators.
Due to ongoing Problems with the conventional secondary air flow measurement at the power plant, which was operated under BEWAG at that time, BEWAG contacted PROMECON to do a test installation. PROMECON installed the MECONTROL Air flowmeters for a test period of 3 months. The MECONTROL Air system makes use of unique patterns of electrical noise generated by particles passing the receiver rods. By correlating these patterns the time of flight between the receiver rods can be accurately measured. Since the principle is base on time measurement it is absolutely drift free.
After very positive results gained during the test, BEWAG issued a tender document for this new technology. PROMECON was awarded the contract and installed 64 MECONTROL Air flow systems distributed to two units with 16 burners and two secondary air ducts each.
MECONTROL Air the system of choice
After two years of experience with the MECONTROL Air system Vattenfall, the new operator of the power plant, decided to equip the measuring points for primary air and pulverized coal flow which are 48 in total as well with PROMECON technology.
Beside these measurements for hot and dusty air, the customer procured six MECONTROL UBC systems to measure the residual carbon in fly ash where three systems were installed at the ESP hoppers of each unit. This in situ microwave based system can be used instead of extractive systems conventionally used.
Repeated sales over years prove the technical advantages and quality of the PROMECON systems MECONTROL Air and MECONTROL UBC. With the help of the PROMECON System the power plant “Reuter West” was able to significantly reduce primary fuel consumption and lower NOx as Carbon emissions.