Abstract
The compressor laboratory at NTNU Valgrinda created in 2018, need some upgrades to properly function as a anti-surge compressor laboratory. The laboratory is being used by control students to learn how to tune controllers to be able to handles changes in pressure and flow as well as getting hands on experience with compressor surge.
The compressor laboratory is lacking a flow sensor, a flow measuring device is needed to be able to accurately measure the flow inside the piping of the laboratory in order to create a working controller for the system. The anti-surge valve does not have a sufficient enough closing speed to be able to handle the rapid changes in flow and pressure a compressor lab produces. To be able to communicate with the new devices a digital communication protocol is a highly preferred addition to the laboratory as opposed to the analog 4-20mA systems.
To handle flow a Siemens FX330 Vortex flow meter was chosen because of the sensor's narrow range that perfectly match the operation range of the compressor, as well as the sensor's ability to measure pressure and flow. The vortex flow meter is currently stationed at NTNU awaiting installation.
The ordered Sitra ET200SP CPU HART 7 protocol PLC is a good fit to digitize the laboratory, but delayed because of a global integrated circuit shortage. The requirement for the PLC are 3 digital signal inputs and a analog signal. The requirement for analog signal makes HART 7 the only available option as it can superimpose digital signals on top of the analog.
To control the new equipment a anti-surge controller has been made. A simulation study of the system was conducted to see if the current valve would be able to control surge at the laboratory. Which according to the simulations in the thesis, very much should.
Future work to be done on the compressor laboratory is installation contact lab mechanic to install the flow meter and PLC. Implement a anti-surge controller in the laboratory. Then a new evaluation needs to be conducted to see if a new valve is required or not.