By injecting biomethane there may be periods when the gas grid becomes full, so that the green gas supplier can no longer lose its gas. To make the most of the biomethane feeding capability, gAvilar has developed a gas booster installation.
By injecting biomethane there may be periods when the gas grid becomes full, so that the green gas supplier can no longer lose its gas. To make the most of the biomethane feeding capability, gAvilar has developed a gas booster installation. This installation is connected to the gas grid in question and brings the gas to a higher pressure after which it is injected into a higher-lying gas grid.
The higher-pressure sub-grids are more extensive in most situations and have, for example, industrial customers who also purchase gas in the summer. The booster system operates completely autonomously and is equipped with extensive protections to prevent unsafe situations. The installation can be read remotely via a web portal so that there is always insight into the functioning of the installation. The measurement data is logged and stored for 5 years so that there is an opportunity to analyze data.
The booster continuously and fully autonomously monitors the pressure in the relevant subnet. If the pressure exceeds the desired value, the booster is automatically switched on at the lowest power. If the pressure continues to increase, the speed of the compressor is increased so that more gas is injected into the higher gas grid. In order to be able to deliver more capacity, multiple compressors can be used. With two compressors, the capacity can be controlled steplessly from 25 to 100% so that the right balance can be achieved in the gas grid.
Depending on the grid pressures and desired capacity, the choice is made for the type of compressor. For lower pressures and beets, an oil-smeared bulkhead compressor is recommended. By applying the right oil filters, this type of compressor allows a very low oil content to be realized. The advantages of this type of compressor are: compact, low-noise, low maintenance costs and competitively priced. The number of running hours before the compressor needs to be overhauled is also very high. Screw or piston compressors should be used for higher pressures and beets. Oil-free compressors are used to prevent oil from entering the gas grid.
Picture: Bulkhead Compressors
When compressing gas, the necessary heat is released. In order to have the temperature of the gas at the desired value, a cooling line has been developed for the smaller capacities. By building this pipe with an extra ground cover, the heat can be released to the ground so that the desired gas temperature can be realized. At higher pressures and capacities, special coolers will have to be applied to get the gas to the desired temperature. In certain circumstances, the use of a chiller may be necessary to get the gas to the correct temperature. In doing so, it may make sense to see if the heat released can be usefully used in other processes.
Picture: Cooling line
The control of the booster installation is done with a Siemens PLC. The compressors are brought to the desired speed using accelerometers. To keep the cooling of the compressors at the desired level, two fans are installed in the cabinet. The speed of these fans is also controlled by a frequency controller so that the temperatures stay within the desired values.
Picture: Control unit