Daniel Goodwin – Managing Director, EX~i Flow Measurement
Not at home! – Domestic gas supply is delivered through a 6-15mm diameter pipe at just over atmospheric pressure (1Bar+).
Imagine a pipe of 100-2,000mm diameter at pressures of up to 180Bar, the rate of flow can be very rapid. When pressure is exerted on a gas or liquid its volume changes, by how much depends on what the gas or liquid is. Flow computers take the rates of flow from a number of measurement devices to calculate the actual volume of gas or liquid flowing, ultimately resulting in a bill which can run to many millions of £/$ per hour.
Flow measurements are usually taken either at the point of production or point of use, although there may be others in between such as:
- Oil rigs and gas platforms. Extraction of hydrocarbons from underground and can be offshore or onshore. Measurements of both quantity and quality are taken since these are crude products which usually contain many impurities, such as sea water or sand, which need to be filtered out.
- Storage sites. With all consumable products, there are peaks and troughs in demand, but it is difficult and expensive to adjust production to match these. Storage sites are used to buffer production and demand. These can be above ground tanks, or underground caverns, converted for storage.
- International transfer. Where pipes cross country borders, such as the Langeled gas pipeline from Norway to the UK, measurements are required to ensure the correct quantity is recorded. This particularly true when the two countries use different base conditions of pressure and temperature, or different metric and imperial units, or different standards of calculation.
- Truck and Ship loading/unloading. Ships are often used to move product from one country to another. Trucks can be used to deliver product to off-grid locations, this is especially true for refined products like petrol or diesel.
- Factories and industrial processes. Very high energy demand processes, such as steel and cement works and brick kilns are required by EU legislation to have accurate measurements of usage, which can also be used to calculate emissions, (see point 10). The flow of coolant systems that are critical to the safety of such processes can be monitored using flow computers.
- Standby electricity generation stations. These are placed at strategic locations, ready to deliver electricity at short notice by using, for example, a modified 747 jet engine running on gas. These sites can be started and shutdown very quickly, usually within 15-20 minutes. This is compared to a coal fired power station which requires about 4 weeks and nuclear power station 4 months. These are especially useful on days when wind and solar are not able to output enough to meet demand.
- Key points in the distribution network, this helps to manage the system but can also be used to detect leaks or theft.
- Biogas injection sites. Waste organic matter is “brewed” to release methane which is mixed with propane to increase the calorific value above the minimum level before injecting into the national grid.
- Hydrogen generation. Mostly standalone but could be used much like a Biogas Injection site, or in a closed system, to store wind and solar energy.
- Exhaust emissions and efficiency measurements using standards such as BS8609:2014. By accurately measuring what fuel goes in and energy/work produced, a measure of efficiency can be made which can be used to predict maintenance requirements and pollution released from the process.
- Steam as a byproduct of electricity generation and other processes can be sold to other nearby factories a means of saving energy used for heating water. Steam is used during steel production for both heating and cooling, as well as mechanical power.
1, 8, 9, and 11 are point of generation.
2, 3, 4 and 7 are transfer points.
5, 6, and 10 are points of use.
The SFC3000 Flow Computer is primarily targeted at the hydrocarbon gas and oil market but can be used to calculate flow of many other gases and liquids including hydrogen, water, steam and CO₂.
Both of the terms “measure” and “calculate” have been used in this article. And for clarity, the flow computer can make measurements directly or can accept values measured by other equipment to perform calculations to produce values that can represent an amount of product. This amount can be expressed as flow with time or a total in terms of volume, energy contained in the product or mass of product. These results can be displayed on the flow computer and/or transmitted to other systems for use.
In summary, if it flows in a pipe Ex-i, can measure it.
Ex~I understands the long term stability, reliability and accuracy required by the measurement industry and has produced a flow computer that meets or even exceeds these expectations. Ex~i Flow Computer customers will continue to benefit from product range expansion through increased modularity.
