Consider cogeneration for savings!
Cogeneration is the simultaneous generation of electricity and heat power, in a single process from the same fuel. Cogeneration is not new. Thomas Edison's first electric generating plant used combined heat and power generation. The principal of co-generation is simple. Conventional power generation on average is only 35% - 40% efficient. Up to 65% of energy potential is released in waste heat.
Out of 100% of the BTUs in diesel fuel only a bit more than 35% is converted to electricity. 35% is expelled out of the radiator as heat and the remaining 30%+ is heat lost through the exhaust and radiant heat. A 12kW genset can produce up to 22,500 BTUs of recoverable heat per hour from the radiator when running under load.
A cogeneration system, as we build them, consists of a engine which powers your generator to produce electricity and a waste heat recovery system to capture heat from the water cooling system and exhaust. Energy efficiency can be more than doubled with co-generation.
Until recently cogeneration implementation has been limited to large industrial applications and commercial facilities. Our implementation of cogeneration would be termed as micro cogeneration or micro CHP (Combined Heat and Power) production.
Harvesting heat before it is expelled from the radiator is the simplest and easiest method of micro cogeneration. This is because it doesn't affect the flow of water and air through the radiator and it does not affect engine performance. Because water cooled engines manage their heat at the thermostat you can't take too much heat from the engine by tapping heat beyond the thermostat. Harvesting heat directly from the engine block is also safe needing only a heat sensor to avoid taping too much heat and it is inexpensive.
Depending on your application, the integration of power and heat production into one on-site cogeneration system can quickly generate savings of up to 35%. The more heat energy you are able to utilize the more you can save. The best candidates for co-generation are those that can utilize the most heat energy. From owners of factories to remote camps, clients are taking advantage of co-generation. Thermal energy is most frequently used for space and water heating, however commercial applications for the use of heat energy abound.
Our co-generation solution:
We’ve developed a solution which:
Our system with a high efficiency heat exchanger within the coolant circulation system is all of the above. If sufficient heat is not removed from the water within the heat exchanger to your heat reservoir, the excess heat is safely pumped out of the radiator into the air. Circulation and heat management are already in place as is shutdown protection should heat be too great within the engine (standard on all of our generators).
You must design your own secondary system with safety systems within the
secondary system because input heat is at 160-180 deg F and must be
managed carefully. If your system doesn't have capacity or isn't sufficiently
protected for pressurization something could pop, even if the temperature is not
at boiling point.
The manifold and engine casing depend on airflow for some cooling. The alternator cooling fan pushes a significant amount of air. Unless the generator is located in a small enclosed space, sufficient air movement is created, avoiding problems.
Heat capture from the exhaust system
The exhaust system dissipates of almost 30% of the BTUs burned within a generator. This heat would otherwise also be lost. The BTU from exhaust gas for a 12kW diesel genset running at load is approximately 14,000 BTU/hr.
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