CCHP is generally made up of a CHP Generator and an Absorption Chiller.
The CHP Generator is a large engine turning a synchronous electricity generator. The engines are typically based on large marine engines or similar high power, high reliability, continuous duty engines. The generators are called synchronous because their output waveform is synchronized to their rotational position, creating the familiar sinusoidal waveform of alternating current. The grid gets its power from synchronous generators because they can precisely control the frequency to 60 cycles/sec. just by setting motor speed. The CHP generator uses the synchronous method so it can be used in cooperation with the grid, or independent of the grid. There are many variants, but the typical CHP Generator rotates at 1800 RPM to produce our 60 cycle power.
What makes a generator a CHP generator: heat collection. Instead of throwing away the leftover heat from the engine (as standby generators do), the heat from the engine jacket and exhaust is collected. That heat can become part of your hot water loop and low pressure steam loop for various heating requirements, e.g. space heating and hot water. By using that heat, the conversion of energy in the fuel to useful electricity and heat jumps from about 40% to 80-90% or more, better than many grid power stations.
The BROAD Absorption Chiller uses “change of phase” latent heat technology to create cooling from the CHP’s waste heat. Watch the attached video about absorption chiller operation.
In the past (the process has been around for over half a century) the salts used were unstable and the machine constructed of bad materials that corroded. BROAD has solved the material problems to create a reliable, maintenance free solution. Since only water vapour is moved, the electrical demands are negligible, displacing air conditioning compressors that would otherwise use a lot of electricity.
There is another reason to use these machines together, balance. If the chiller were not there, the CHP’s waste heat could not be fully used in summer months, and would have to be wasted to its radiator. Under such circumstances, the CHP would have to be downsized to meet summer demand, only a fraction of the total energy used on your site, otherwise the wasteful operation would nullify financial and “green” benefits. The BROAD chiller can take the heat from the CHP and make it useful in the summer, so that the CHP can be justified at a much greater load, perhaps all of it, and still be efficient. Balance is what it is all about.
There are details. Efficient water loops can help you get maximum efficiency out of the system. You will be able to displace boilers and centrifugal chillers: we can help you with just “how far” works for your situation. Balance is the big picture, final efficiency is in the details.
Description of principles of modern absorption chillers
BROAD chiller working example, Chinese captions