Compressed air balancing in a power plant at a chemical park

Flow measurement of the entire volume of compressed air generated in the L57 power plant at the Krefeld-Uerdingen CHEMPARK site

As the operator and manager of CHEMPARK, one of CURRENTA‘s tasks is to provide the companies located there with the necessary infrastructure for their production. This also includes the supply of compressed air. With dense compressed air networks, CURRENTA supplies companies at the CHEMPARK sites in Leverkusen, Dormagen and Krefeld-Uerdingen reliably and comprehensively with compressed air at various pressure levels and with control air.

CURRENTA produces compressed air in Krefeld-Uerdingen with several generation plants. The redundancy of these generating plants ensures maximum security of supply for consumers. Compressed air is a valuable product and work tool that requires a corresponding amount of energy to generate. Quantity measurements are essential for the efficient generation and efficient operation of a compressed air network. For balancing purposes, the quantities generated and fed into the network are compared with the quantities withdrawn from the network. The generating units are equipped with thermal mass meters or Venturi flowmeters to record the compressed air volumes generated. Other measurement technologies such as apertures, vortex, and Coriolis meters are also used for the consumption measurements.

These inline flowmeters have different measurement accuracies and dynamics. Depending on the mode of operation of the various generating units, there were always discrepancies in the balancing of generation and consumption quantities, the cause of which was suspected to be an incorrect quantity measurement on one of the generating units. In order to be able to get to the bottom of the cause of the fluctuating discrepancies, it was decided to empirically record the total amount of compressed air generated in the L57 power plant by means of a control measurement.

Solution

Due to the availability and redundancy requirements, shutting off the DN600 compressed air line to install a wetted quantity meter was out of the question. Rather, the measurement engineers thought of non-invasive ultrasonic flow measurement from the outset. In Krefeld-Uerdingen they have had a lot of experience with this. As a field sales engineer, Heinrich Brucks has been supplying industrial companies on the Lower Rhine with FLEXIM’s clamp-on ultrasonic technology for almost 20 years. During this time, both he and the products he supplies have gained an excellent reputation. If you have a challenging flow measurement task, call Heinrich Brucks.

Heinrich Brucks was therefore commissioned to implement the compressed air measurement at the L57 power plant, initially as part of a measurement service. The special challenge with this measurement lies in the disturbed flow profile and the possible very high flow velocities. The most suitable measurement location is behind a bend. If all three generation units of the power plant are producing at full capacity, flow velocities of over 20 m/s can be achieved. However, a characteristic advantage of FLEXIM’s non-invasive measurement technology is that the instrumentation can be experimented with at the specific measurement location without any impairment of the plant operation. The setup of the measuring point with two pairs of Lamb wave transducers of the type GRH proved to be the ideal configuration. Both pairs radiate through the pipe with a sound path and are arranged as an X over the pipe cross-section. As a result, the flow profile disturbance can be excellently compensated.

The results of the measurement proved to be so revealing that the measurement service was extended several times and the decision was finally made to use a stationary clamp-on ultrasonic system for permanent instrumentation. The FLUXUS? G722 is used as the transmitter. It has a high-performance processor that enables fast channel switching between its two independent measurement channels. In the event of strong flow profile disturbances and turbulence, the high-performance processor enables the fast, simultaneous recording and processing of measurement data from the two independent measurement channels A and B and the output of an average value via the calculation channel Y. This effectively reduces cross-flow effects and better reflects the actual flow profiles.

The measured value is output as a standard volume flow. For this purpose, the transmitter has process inputs for recording temperature and pressure data, with which it converts the operating volume flow according to DIN 1343 to a reference pressure of 1.01325 bar and a temperature of 0 °C.

Advantages

• Reliable and precise, non-invasive recording of compressed air quantities (standard volume flow)
• Simple retrofitting without any impact on the existing piping system with minimal installation work and without the costs for additional fittings and piping work
• Decades of convincing experience with FLEXIM‘s clamp-on ultrasonic measurement technology
• Fast channel switching for good compensation of the disturbed flow profile
• High measuring dynamics also enable the recording of small consumption quantities
• Advanced Meter Verification for documented signal quality and measurement accuracy

Measuring Point and Instrumentation

Pipeline: steel, DN600 Medium: compressed air, ~ 6 bar(a)

1 stationary clamp-on FLUXUS? G722 ultrasonic system (two measuring channels, fast channel switching)

2 pairs of GRH1N52 clamp-on ultrasonic transducers (Lamb wave) for gases, mounted in a single-path diagonal arrangement in VARIOFIX

“FLEXIM’s flow measurement provides us with reliable measured values, on the basis of which we can further optimise our compressed air supply.”

Thomas Oel, Metering, Technical Office, CURRENTA, Krefeld-Uerdingen site

Customer

Currenta , CHEMPARK Krefeld-Uerdingen, Germany

As manager and operator of the CHEMPARK with sites in Leverkusen, Dormagen and Krefeld-Uerdingen, CURRENTA maintains one of the largest chemical parks in Germany at one of the largest industrial sites in Europe. CURRENTA offers chemical-technical services at the three locations for a total of around 70 companies in the CHEMPARK. These include energy supply, waste disposal, infrastructure, safety, analytics, and training. There are also other services such as maintenance and logistics of the two subsidiaries Tectrion GmbH and Chemion Logistik GmbH. CURRENTA GmbH & Co. OHG has been trading as CURRENTA since 2008 and employs around 3,400 people (approx. 5,400 employees including subsidiaries). Sales of around EUR 2 billion (EUR 2.3 billion including subsidiaries) were generated in 2021. A third of North Rhine-Westphalia‘s chemical production takes place in the CHEMPARK with its three sites in Leverkusen, Dormagen and Krefeld-Uerdingen on an area of 11 square kilometers and in around 500 companies.

Uerdingen has been a chemical site since a small factory for azo dyes was founded in 1877. Today, more than 8,600 employees at CHEMPARK Krefeld-Uerdingen manufacture around 2,000 different chemical products. These include plastics, white and colour pigments as well as intermediate products for pesticides, odorants and flavourings. The 260-hectare site has established itself as the leading polycarbonate and polyamide site in Western Europe. In addition, the world‘s largest production facility for inorganic pigments is concentrated in CHEMPARK Krefeld-Uerdingen

For further information, please contact FLEXIM:

[email protected], flexim.com.