Are gas turbines losing market share to gas engines? This is a question that does not seem to escape the minds of those involved in the power plant sector. For larger-scale heat and power operations, gas turbines have traditionally been the only option. Any industry expert will tell you that the situation is slowly but steadily changing, thanks to engines’ increased adaptability. As the power plant tradition is put to the test, we compare the two types of power plants, highlighting the advantages and disadvantages of each.
Gas engines and turbines are the two principal power sources available to developers of distributed generating systems. Thousands of cogeneration (combined heat and power or CHP) facilities across the world have shown both. Electric utilities, hospitals, universities, district heating, seawater desalination, food processing, textiles, petrochemical refining, chemical processing, pharmaceuticals, pulp and paper, and general manufacturing all use gas engines and turbines in CHP applications. In terms of efficiency, dependability, emissions performance, and operating costs, both systems have continuously improved over time.
Both gas turbines and gas engines have distinct characteristics. In this article, we’ll go through it in further detail.
What is a gas turbine?
A gas turbine is an engine that is powered by the pressure of compressed air and fuel being burned. The brain of the power plant is a gas turbine, which is a combustion engine that turns liquid fuels, particularly natural gas, into mechanical energy. This energy drives a generator, which generates electricity. A fuel-air mixture is heated to extremely high temperatures within it. The turbine blades spin quickly as a result of this. Aeroplanes, trains, ships, electrical generators, pumps, gas compressors, and tanks are all powered by gas turbines.
The air is first compressed by a compressor before being sent into the combustor. Fuel is continuously combusted here to produce high-temperature, high-pressure gas. A gas turbine for industry expands the gas produced in the combustor in the turbine (a vaned rotor constructed by joining many blades to a circular disk), resulting in the rotational energy required to run the compressor at the previous stage. An output shaft is used to deliver the leftover energy. A turbine control system helps to monitor and increase safety. IS200TRTDH1D and IS200VTURH2B are some examples of GE Mark V control system parts.
What is a gas engine?
A gas engine is a type of engine that is powered by gas production, expansion, or combustion. Gas engines are mass-produced in large quantities and are inexpensive, but central power plants are a one-of-a-kind technology. Several gas engines are coupled to produce generating sets in a power plant setup. Every engine, on the other hand, has a shaft that links to an electric generator. The sets come in conventional sizes ranging from 10 to 20 megawatts. The high-efficiency functioning of the gas engine using natural gas and city gas, as well as low-calorie gases generated in gasification melting furnaces, helps greatly to CO2 reduction.
Difference between Gas Turbine and Gas Engine
The distinction between a gas turbine and a gas engine is described in terms of various elements. When choosing a gas turbine or a gas engine for a certain application, various criteria, such as those listed, are taken into account.
The main distinctions between a gas turbine and a gas engine are:
- Its efficiencies range from 29 to 33%, whereas gas engine efficiencies range from 48.5 to 49%.
- The energy ratio of cogeneration in it is composed of electricity (33%), steam (50%) and loss (3%). (20%). Electricity (49%), steam (15%), hot water (13%), low-temperature water (10%), and loss make up the energy ratio of cogeneration in a gas engine (13%).
- Steam supplies the majority of the heat in a gas engine. The heat is provided by hot water and some steam in the gas engine.
- The gas turbine has a total efficiency of 80 to 83% for cogeneration. The cogeneration efficiency of the gas engine ranges from 63.5% to 77%.
- The gas engine and turbine have high electrical efficiency. The gas engine’s electrical efficiency is excellent.
- The temperature and amount of exhaust gas produced by the gas turbine are both high.
- The exhaust gas temperature from the gas turbine is very low. NOx emissions from a gas turbine range from 15 to 25 parts per million. NOx emissions from gas engines are at 57 parts per million.
- The start-up time for it is 20 minutes, whereas the start-up time for a gas engine is 10 minutes.
- Both have a very long maintenance interval.
- With more gas engine products in the bigger (more than 3 MWe) size range coming to market, enhanced performance (i.e. higher electrical efficiencies), and a higher demand for flexible operation, gas turbine suppliers are feeling the heat.
- Peaking power plants must be able to operate flexibly, with rapid ramp-up and ramp-down times. Gas engines are ideally suited to these requirements.
- Although gas turbines will continue to be used, especially in larger peaking facilities, the move to gas engines is well underway.
- In mid-sized and large industrial sites with power and high-temperature steam/heat needs, 30 MWe gas turbines will likely continue to have an overwhelming market share. Gas engines (100 kWe to 20 MWe) are gaining market share in a range of different end-use industries. Gas engines have gained market share at the expense of gas turbines, which can’t ramp up and down as quickly as gas engines.
Gas Turbine or Gas Engine?
This is a question that every power generation project developer must consider. Small projects often use reciprocating engines, but larger projects benefit from turbine gas power plants. When you have to choose between power plants, the difficulty emerges.
In power generation applications, both gas turbines and gas engines have proven to be beneficial. Each technology has found favour with people looking for reliable power and thermal alternatives and is widely recognized in the marketplace today. All of this suggests that gas-fired CHP systems have a bright future. The time has come for power users and producers in industrial and commercial establishments to investigate the cost-effectiveness of CHP using today’s gas engine and turbine technologies.