*3.3. Fuel Gas Unit*

The gas turbine, the hot-water boiler unit, and the power generating unit are the three major users of the fuel gas unit, and thus the primary function of this unit is to condition the station incoming gas to meet their specific requirements [34]. The suction side of the compressor station is where the fuel gas is extracted from. Fuel gas treatment is designed to run in two separate trains with 100 percent capacity each. A filter is used to remove liquids and deposits from the pipeline before the gas is released into the atmosphere. After going through the filtration process, the gas is sent via a heat exchanger that is powered by hot water. This heat exchanger will preheat the gas in order to compensate for the temperature loss that will occur as a result of the Joule–Thompson effect, which will be accomplished by lowering the pressure. In this component of the system, a pressure relief valve will be provided in order to prevent an excessive buildup of pressure brought on by the heating of the gas in the event that the heat exchanger becomes clogged. The pressure of the gas will be lowered upstream of the heat exchanger until it reaches the desired pressure of 18 to 34 bar (depending on gas turbine supplier). In the event that the controller fails, there will be two medium-driven shutoff valves installed upstream of the pressure reduction valve. This will prevent the system from becoming overpressurized. On the low-pressure side of the system, a relief valve has been planned for installation, and its sole function will be to prevent the system from shutting down as a result of pressure peaks in the event that the redundant system is automatically switched on. While the fuel gas is being taken upstream of the metering system, the turbine flow meter that is meant to be suited for fiscal purposes will be measuring the fuel gas stream as it flows through the system. After this step, the gas is prepared for use in the gas turbine by being conditioned.

#### *3.4. Hot-Water Boiler System*

For both the radiator in the room- or building-heating system and the gas preheating in the fuel gas system, the heating medium, which is water that may be conditioned for heating purposes, will be given. This water will serve as the heating medium. In order to prevent the release of greenhouse gases, the seal gas that is produced by the compressor units will be burnt in the boiler units.

#### *3.5. Vent and Blowdown System*

In the event that an emergency depressurization is required, the station will be outfitted with a vent and blowdown system that has the capability of lowering the operating pressure to 6.9 bar in less than 15 min. The vented gas will be collected through one of three distinct headers at the end of the process. The suction area of the station is included in the first header, while the compressors are included in the second header and the discharge area is included in the third header. The blowdown system is constructed in such a way that it directs a consistent mass flow to the vent stack. This will be accomplished by the carefully orchestrated opening of the blowdown lines that are located in close proximity to the vent. After passing through the silencer, the gas is routed to the vent stack for final disposal. In addition to the emergency blowdown system, the blowdown system also has a number of manually operated vents that are connected to it. Venting for maintenance purposes requires the use of these manual vents.
