In a Thermoelectric Plant only 37% of the GN fuel energy is transformed into electricity.

If there are resources available for further investment, through a combined cycle, one can get to a yield of around 50% using the energy of combustion gases to generate steam and feed a steam turbine. A co-generation plant can achieve a yield of up to 90% when it takes the remaining energy in the exhaust gases to produce cold and heat.Unlike the electricity, there are strong technical limitations for heat transport and mainly for the cold transport.

The limit of distance to be economically viable the transport of steam or hot water is around 5km and the cold, using the iced water as a vehicle, the economic distance is no more than 500m.

Regarding Energy Efficiency there are no doubts of the co-generation benefits in relation to the simple thermoelectric generation. However, to use the heat and the cold that can be generated in a cogeneration plant, it is necessary that it is located next to the heat and cold consumers.

Consumers of cold and heat are the residential and commercial buildings, shopping malls, supermarkets, hotels, hospitals, etc.

In the current state of the technique available to the Brazilian consumer, the Co-generation plants occupy large areas, require buildings with high ceilings and cause reasonable levels of noise pollution.
As the consumers are almost always in places with appreciation of the properties, with high cost of m2 and major environmental restrictions in relation to the noise pollution, it is created the impasse to enable the Co-generation plants.
In this context we present a solution of Co-generation Modular Plans, as a competitive alternative to be explored.
A modular plant can be implemented in a much smaller area, with no need for high ceilings, coming sheltered in containers equipped with acoustic panels. These plants are produced for open-air work not compromising an able-to-be-built area of the undertaking.
At the same time that contributes to a large increase of energy efficiency when it simultaneously generates electricity, iced water for air conditioning and hot water, the Co-generation Plant contributes to reduce global warming when eliminates, in the atmosphere, gases at considerably lower temperatures, 170º C instead of 570º C, also reducing the emission of CO2 in the atmosphere which contributes for the reduction of the greenhouse effect.



CMCT (CENTRAL MODULAR DE CO-GERAÇÃO TUMA; TUMA CO-GENERATION MODULAR PLANT): BASIC OPERATING CONCEPT.

CMCT (Central Modular de Co-Generation Tuma; Tuma Co-Generation Modular Plant): it is a result of the effort and investment of Tuma in researches and development to make the Co-generation technically and economically feasible for small and middle-sized applications.

The energy of the GN is initially used to generate electricity by a burning in an electrical generator group.

The exhaust gas at temperatures up to 570º C feed directly the cooler units by absorption that produces cold water without the need for intermediate generation of steam.

The cold water is used for air conditioning systems or other applications in industrial processes.

The exhaust gases leave the cooler units by absorption at temperatures around 170º C, still with enough energy to produce hot water.

From the energy coming from the GN burning, besides the part used to produce electricity and from the energy that follows the exhaust gases, a third part is dissipated in the cooling water of the gas engines.

The hot water takes the engines to 98º C, being used for several purposes and also for complementary feeding of energy the cooler units by absorption, increasing the production of cold water.

In order to view the economic advantages of CMCT, we illustrate with energy data from January 2004, in the city of Belo Horizonte:
1. Average cost of electricity paid by a residential / commercial consumer of low voltage: R$ 0,45 / kwh
2. Average cost of GN for Co-generation - R$ 0,532/m3.
3. Production of electricity per m3 of GN - 3.8 kwh/m3.
4. Cost of the electrical kwh generated with GN - R$ 0,14
5. Production of cold as sub-product - For each 100 kwh of electricity generated, free 35TRh of air conditioning or 105,840 kcal are produced.
6. Production of heat as sub-product - For each 100kwh of electricity generated, it is produced enough heat to heat water and replace energy of 145 kwh that would be consumed by electrical resistances.