The cost of electricity in centralized systems is very high these days. The same applies to general heating utilities. Therefore, Mini-CHPs are becoming increasingly popular among owners of enterprises of different specializations. The cost of installing such a station is quite expensive, but it pays off very quickly. The main element of any mini-CHP is a gas piston unit.
Design features
Modern gas reciprocating plants are operating on internal combustion engines. At the same time, not only propane or butane can be used as fuel, but also:
biogas;
flare;
sewage gas;
associated;
coke, etc.
In addition to the engine, the design of the gas piston unit includes:
a generator designed to convert the mechanical energy of rotation of the motor shaft into electrical energy;
hot water or steam boiler;
a radiator that is part of the engine cooling system;
pumps, thermostats, heat exchangers.
Such a system may also include air conditioning. Most often, mini-CHPs use cheaters.
Principle of operation
The main advantage of gas reciprocating plants is their high efficiency at a relatively low cost. In the event that the equipment runs on gas supplied through Russian highways, its electrical efficiency will be about 43%. However, in most cases, gas piston units can operate in cogeneration mode. In this case, the heat generated by the internal combustion engine is also used. The coolant warmed up during engine operation enters a special exchanger. Here it transfers heat to water or antifreeze circulating along the heating system highways. In this case, additional heating of the coolant occurs in a special waste heat boiler due to the heat of the exhaust gases of the internal combustion engine.
When using such a scheme of operation of a mini-CHP, the plant efficiency can increase up to 90%. The ratio of engine power and energy generated by the installation is 1x1. Which is a very good indicator. Indeed, at the same time, 1 kW of the total (thermal and electrical) energy generated per 1 kW of motor power.
Trigeneration Models
A gas piston generator set of this type is the most convenient to use, but also the most expensive equipment. In this case, the heat generated by the engine can be used not only to heat the shops and production premises of the enterprise in winter, but also to condition them in the summer. This goal is achieved by the inclusion of a cheater operating in absorption technology in the mini-CHP system. Such units use gas, steam or hot water in their work .
Sometimes the design of the gas engine is supplemented by compressor air conditioning. However, the use of such a device in most cases is considered impractical, since it works from electricity. And this, in turn, causes additional unnecessary costs.
Features of choice
The power of equipment such as a gas piston unit can fluctuate in very large limits. Of course, when choosing this equipment, this indicator is paid attention to first. There are installations on the modern market, the power of which can amount to tens of kW or MW. But the most popular equipment is considered to be 100-2000 kW. Even if the enterprise requires large capacities, it is usually purchased not one large installation, but several small ones. It gives a lot of advantages. These include:
More reliable system operation. In the event that one of the installations fails, temporarily work can be continued using the remaining ones. As a result, the workshops will not be idle.
The possibility of more rational use of the system. For example, in the winter period of time, when there is no need for heating, some of the units can be turned off. The same goes for the peaks and dips of production itself.
A feature of gas piston plants is that they cannot be used at a load of less than 30%. It is constantly quite difficult to use a large unit at full power. When using several installations, this problem also disappears.
Calculation of gas piston installation
The cost of 1 kW per hour generated by equipment of this type is difficult to calculate independently. It’s easier to use a specialized online calculator or software. In the program form, you just need to enter data such as:
It will also be necessary to indicate whether the station uses the cogeneration and trigeneration modes.
Gas piston plants, the price of which depends on capacity and functionality (from 100 thousand to 15-16 million rubles), in most cases turn out to be equipment, in use it is very profitable. Some models can pay off in a few months. The maximum payback period is 4 years.
Mounting Features
When assembling a mini-CHP, the standards provided by law must be observed. A gas piston installation can be mounted both outside the production room and directly on its territory. Also, such units are sometimes installed in extensions.
When installed on the street, mini-CHP plants are usually located at a distance of at least 5 meters from the building. If it is located in a separate building, the latter should be located from the workshops at a distance of 10-20 m. In the production building itself, mini-CHPs should be separated by special technical rooms from all sides. At the same time, people should not be constantly in such rooms. The same rules are observed when the station is located in the annex.
Gas piston plants of Russian manufacturers
Equipment of this type, manufactured at domestic enterprises, in most cases is of good quality and reliability. And although it may be inferior to European-made equipment in some respects, it is considered quite suitable for use in mini-thermal power plants. Moreover, such units are usually cheaper than manufactured, for example, in Europe.
At modern domestic enterprises, a variety of brands of equipment such as gas piston units can be used. Manufacturers LLC Energo-Status, Zorya-Mashproekt, NPO named after Frunze, Altai-Dieselenergo and many others produce quite reliable units of this type. Russian models of the AGP line manufactured by Rybinskkompleks are also very popular with owners of enterprises operating from mini-thermal power plants.
Technical characteristics of AGP-100
Parameters of gas piston plants of Russian manufacturers may have different depending on the line and purpose. AGP power plants are no exception in this regard. There are many modifications to this equipment. One of the most popular models in the domestic market is the AGP-100. It is intended to provide consumers with three-phase alternating current at 50 Hz and 400 V. Depending on the quality of the gas used for operation, it can generate energy by 70-100% of its rated power. If necessary, it can be used for heat recovery. Below for clarity, we present to your attention a table with the technical characteristics of this unit.
Parameter | Value |
Power | 100 kW |
Rated current | 180 A |
Motor shaft speed | 1500 rpm |
Type of fuel | Any gas |
Oil consumption | 0.5% of fuel consumption |
Cooling system | Radiator |
Fuel consumption | 35 m 3 / h |
The cost of electricity generated by this installation is about 0.7 rubles per 1 kW / h at maximum load.
European installations
Such equipment is also used by domestic enterprises quite often. One of the most popular brands of imported models is Caterpillar. Gas piston plants of this manufacturer are valued primarily for:
high efficiency;
the possibility of using a wide range of additional equipment;
ease of installation;
savings in terms of fuel consumption;
excellent performance;
the ability to use without the need for major repairs for a long time (up to 100,000 hours).
Thus, a modern gas piston installation - the equipment is actually very convenient and reliable. Of course, you can use it with such excellent indicators of profitability and productivity, not only in production shops, but also in various kinds of social facilities: in hospitals, schools, kindergartens, etc.