Pressurised water injection

The equilibrium cell and its loading lines were vacuumed prior to introducing the natural gas, then the system was pressurised by injecting the gas up to a certain pressure at the test temperature. Water was then injected into the cell in different steps to achieve the desired water/gas ratio (i.e., 1, 2, 3,100 bbl/MMscf). In each step, after achieving equilibrium following hydrate formation, speed of sound (SoS) and gas compositions were measured, depending on the device actually used. 

The method implies injection of a mixture of 3 radioactive tracers each being distributed into one of the 3 phases. The tracers must show such differences in the emitting y-radiation energy spectra that they can be simultaneously detected by on line y-spectrometry. Candidate tracers are Br-82 as bromobenzene for oil, Na-24 or La-140 for water, and Kr-85 for gas. The tracers are injected simultaneously at a constant rate into the flow in the pressurised pipe, and the concentration is detected as series of instantaneous measurements taken downstream as illustrated in figure 2. 

The capillary column has to be pre-conditioned with buffer solution for 6 min. The sample introduction is carried out by pressurised injection of water, sample and buffer in the capillary column each at 5 kPa for 5 s subsequently. Electrophoresis is performed for 8 min at 500 V/cm at 35°C in the running buffer solution. UV detector is set to 195 nm for analysis. Then the column is washed subsequently for 3 min with 0.1 M sodium hydroxide, 4% phosphoric acid containing 20% acetonitrile and 20% acetonitrile in water. 

Diverse Water, whole blood, culture cells Ultrasound-assisted filtration UV-Vis Diverse Multi-commuted flow injection system with three parallel analytical paths pressurised gas as the fluid propellent [150]... 

In the event of a loss of coolant, water is first injected from two sub-systems into the distribution headers between the common pump outlet header and the individual channel feeder pipes of the failed circuit from tanks pressurised to 10 MPa which are connected by fast acting valves. At the same time, a third sub-system... 

There is a passive system for providing make up water in the event of a LOCA, the Emergency Coolant Injection System (ECIS). This uses steam injectors to pump water from the containment tanks into the RPV. The steam is taken from the top of the pressuriser. There is two times redundancy. This system can be combined with a bleed system to provide a second route for decay heat removal. Fig. 7.5.2. gives a schematic diagram of the safety systems and the nonsafety grade heat removal systems. 

Emergency Coolant Injection System (ECIS). Passive Yes 2 steam injectors take steam from pressuriser and water from containment tanks... 

One of the easiest to control is the direct injection of water as a spray. This has the further advantage that it will cool the gas, which will be necessary if it has been compressed or if the fuel gas has been formed by reforming some other fuel and is still hot, as in Chapter 8. The method involves the use of pumps to pressurise the water, and also a solenoid valve to open and close the injector. It is therefore fairly expensive in terms of equipment and parasitic energy use. Nevertheless, it is a mature technology and is widely used, especially on larger fuel cell systems. 

The risk profile of a typical plant shows the peak at the moment of shutdown of the reactor and again at the start up. The peak at shutdown is related to switch over to the RHR System, and it is due to possible inoperability of the system which cannot be verified before the system s operation is required. This phenomena is well understood and the measures to reduce the risk are mainly related to assuring the diversity in heat removal (like steam generators full with water, etc.). The risk peak at the start-up is often related with the cold over-pressurisation event which is especially dangerous during the water solid conditions, when inadvertent safety injection or malfunction of charging systems can cause major rupture of RCS. Interlocks and procedures were developed and employed to cope with this phenomena. 

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