In order to design, optimize and operate CO2-transportation and injection systems in a safe and efficient way, engineers will need to quantify processes and phenomena that may not be readily covered by existing engineering tools. One of those processes is the depressurization of pipes or vessels, which is relevant to several safety and operational aspects, involving running-ductile fracture, transient flow and temperature variation, as pointed out in the following. Data and models for pipe depressurization are also employed to describe the upstream boundary condition for safety studies of the release and dispersion of CO2 in the terrain. The facility consists of two parts: 1. A pipe of length 62 m and inner diameter 41 mm, depressurized using a rupture disk, full bore or through an orifice. 2. A cylindrical vessel of volume 58 L and inner diameter 273 mm, depressurized through a valve. The two parts share a common infrastructure including gas supply, compressors, cooling system, vacuum pump and gas chromatography. At the moment, pure CO2 or mixtures of non-flammable gases can be employed. The maximum operating pressure is 200 bar for the pipe and 150 bar for the tank, and the initial temperature can be controlled between 5 and 40 °°C for both.
The depressurization pipe is densely instrumented with fast pressure and temperature sensors and the inside has been honed to reduce the influence of friction. The length of the tube allows for relatively long-duration experiments, allowing the study of both pressure and temperature effects in one experiment. 16 fast-response pressure transducers are flush mounted to the internal surface of the pipe with dense distribution close to the rupture disk. They are logged at a frequency up to 100 kHz. 23 Type E thermocouples are installed for the measurement of the fluid temperature, among which 11 are placed at axial positions together with pressure sensors on opposite sides of the pipe. The remaining 12 thermocouples are installed at the top, bottom and side of the pipe at four locations in order to capture any stratification of the flow. They are logged at a frequency up to 1 kHz. The tank is instrumented with 2 pressure sensors logged at 30 Hz and 25 type T thermocouples logged at 90 Hz. The mass flow can be measured through the use of scales. We are not aware of a similar installation currently in operation.
Located in the thermal laboratories of NTNU/SINTEF with its available infrastructures and services and directly adjacent to the offices of leading scientists in the field of SINTEF and NTNU. Further advanced facilities for flow experiments are planned adjacent to this facility.