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Energy Mass Balance
Energy Mass Balance
Electricity & Natural Gas Energy Mass Balance - by Justin Wright (Hatlar Project Manager)
The continuing legislative requirement for improving resource efficiency revolves around understanding where exactly energy is used throughout an industrial site. Knowing where the energy is used and in what proportions is the cornerstone of resource efficiency and the first step is an energy mass balance.
Virtually all businesses will have some understanding of the total energy consumed by virtue of the fact that energy bills are paid and the costs are often significant enough to be noted and or reported. However the distribution of the energy through a site is often poorly understood, especially in more complex sites with a large range of processes and energy consuming equipment.
There are many methods, with varying degrees of accuracy, to determine how energy is distributed around a site. Natural gas is very difficult to accurately measure without sub metering; there is currently no technology available that can measure low pressure natural gas within a pipe. If only one piece of equipment uses natural gas the process is obviously very easy but if multiple pieces of equipment are using gas at varying times or at the same time it becomes far more complicated. Unless a pulsed output is available on the sites main gas meter, two people will be required to determine the gas mass balance. One person will record gas meter data every minute whilst another person turns on gas using equipment in a staged way to ensure that a piece of equipment is allowed to start up and run continuously for at least an hour at normal operating conditions, before turning on the next piece of equipment.
Electricity measurement does lend itself to data logging making the mass balance less difficult; however a common starting point is to determine the rating of individual pieces of equipment based on the specification plate. (Natural gas does not lend itself to this method as gas equipment is set up primarily to deliver the process heat required) The major limitation to this method is estimating the actual load on a piece of equipment over a period of time. A far better method is to use a clamp meter data logger and measure the electricity used of a range of equipment within a distinct process. A normal production day of data is ideal as this can readily be extrapolated over an entire operating year to give a reliable estimation on the electricity used. Deciding which process should be measured requires some skill and planning and is often limited by how the electricity is distributed. But as a rule wherever possible the measurement of data should correspond with the process flow of the factory operations.
Most factories have highly skilled electrical and maintenance fitters that can perform this type of work but rarely do they have the resources and time required outside of their normal duties (keeping the process running). Hatlar group, in conjunction with electrical and maintenance fitters, can determine your sites electricity and natural gas mass balance to a sufficient level to meet all legislative requirements and to help you reduce electricity and natural gas consumption costs.
