What is better, more reliable, more economical for an autonomous power plant: gas piston or gas turbine power units? About gas turbines for non-engineers Steam and gas turbines definition
Thermal turbine of constant action, in which the thermal energy of compressed and heated gas (usually fuel combustion products) is converted into mechanical rotational work on a shaft; is a structural element of a gas turbine engine.
Heating of compressed gas, as a rule, occurs in the combustion chamber. It is also possible to carry out heating in a nuclear reactor, etc. Gas turbines first appeared at the end of the 19th century. as a gas turbine engine and in terms of design, they approached a steam turbine. Structurally, a gas turbine is a series of orderly arranged stationary blade rims of the nozzle apparatus and rotating rims of the impeller, which as a result form a flow part. The turbine stage is a nozzle apparatus combined with an impeller. The stage consists of a stator, which includes stationary parts (housing, nozzle blades, shroud rings), and a rotor, which is a set of rotating parts (such as rotor blades, disks, shaft).
The classification of a gas turbine is carried out according to many design features: in the direction of the gas flow, the number of stages, the method of using the heat difference and the method of supplying gas to the impeller. In the direction of the gas flow, gas turbines can be distinguished axial (the most common) and radial, as well as diagonal and tangential. In axial gas turbines, the flow in the meridional section is transported mainly along the entire axis of the turbine; in radial turbines, on the contrary, it is perpendicular to the axis. Radial turbines are divided into centripetal and centrifugal. In a diagonal turbine, the gas flows at some angle to the axis of rotation of the turbine. The impeller of a tangential turbine has no blades; such turbines are used at very low gas flow rates, usually in measuring instruments. Gas turbines are single, double and multi-stage.
The number of stages is determined by many factors: the purpose of the turbine, its design scheme, the total power and developed by one stage, as well as the actuated pressure drop. According to the method of using the available heat difference, turbines with speed stages are distinguished, in which only the flow turns in the impeller, without pressure change (active turbines), and turbines with pressure stages, in which the pressure decreases both in the nozzle apparatus and on the rotor blades (jet turbines). In partial gas turbines, gas is supplied to the impeller along a part of the circumference of the nozzle apparatus or along its full circumference.
In a multistage turbine, the energy conversion process consists of a number of successive processes in individual stages. Compressed and heated gas is supplied to the interblade channels of the nozzle apparatus at an initial speed, where, in the process of expansion, a part of the available heat drop is converted into the kinetic energy of the outflow jet. Further expansion of the gas and the conversion of the heat drop into useful work occur in the interblade channels of the impeller. The gas flow, acting on the rotor blades, creates a torque on the main shaft of the turbine. In this case, the absolute velocity of the gas decreases. The lower this speed, the greater part of the gas energy is converted into mechanical work on the turbine shaft.
Efficiency characterizes the efficiency of gas turbines, which is the ratio of the work removed from the shaft to the available gas energy in front of the turbine. The effective efficiency of modern multistage turbines is quite high and reaches 92-94%.
The principle of operation of a gas turbine is as follows: gas is injected into the combustion chamber by a compressor, mixed with air, forms a fuel mixture and is ignited. The resulting combustion products with high temperature (900-1200 °C) pass through several rows of blades mounted on the turbine shaft and cause the turbine to rotate. The resulting mechanical energy of the shaft is transmitted through a gearbox to a generator that generates electricity.
Thermal energy gases leaving the turbine enter the heat exchanger. Also, instead of generating electricity, the mechanical energy of the turbine can be used to operate various pumps, compressors, etc. The most commonly used fuel for gas turbines is natural gas, although this cannot exclude the possibility of using other types of gaseous fuels. But at the same time, gas turbines are very capricious and place high demands on the quality of its preparation (certain mechanical inclusions, humidity are necessary).
The temperature of gases leaving the turbine is 450-550 °С. The quantitative ratio of thermal energy to electrical energy in gas turbines ranges from 1.5: 1 to 2.5: 1, which makes it possible to build cogeneration systems that differ in the type of coolant:
1) direct (direct) use of exhaust hot gases;
2) production of low or medium pressure steam (8-18 kg/cm2) in an external boiler;
3) production of hot water (better when the required temperature exceeds 140 °C);
4) production of high pressure steam.
A great contribution to the development of gas turbines was made by Soviet scientists B. S. Stechkin, G. S. Zhiritsky, N. R. Briling, V. V. Uvarov, K. V. Kholshchevikov, I. I. Kirillov and others. the creation of gas turbines for stationary and mobile gas turbine plants was achieved by foreign companies (the Swiss Brown-Boveri, in which the famous Slovak scientist A. Stodola worked, and Sulzer, the American General Electric, etc.).
In the future, the development of gas turbines depends on the possibility of increasing the gas temperature in front of the turbine. This is due to the creation of new heat-resistant materials and reliable cooling systems for rotor blades with a significant improvement in the flow path, etc.
Thanks to the widespread transition in the 1990s. natural gas as the main fuel for power generation, gas turbines have occupied a significant segment of the market. Despite the fact that the maximum efficiency of the equipment is achieved at capacities from 5 MW and higher (up to 300 MW), some manufacturers produce models in the 1-5 MW range.
Gas turbines are used in aviation and power plants.
- Previous: GAS ANALYZER
- Following: GAS ENGINE
A turbine is an engine in which the potential energy of a compressible fluid is converted into kinetic energy in the blade apparatus, and the latter in the impellers into mechanical work transmitted to a continuously rotating shaft.
Steam turbines by their design represent a heat engine that is constantly in operation. During operation, superheated or saturated water vapor enters the flow path and, due to its expansion, forces the rotor to rotate. Rotation occurs as a result of the steam flow acting on the blade apparatus.
The steam turbine is part of the steam turbine design, which is designed to generate energy. There are also installations that, in addition to electricity, can generate thermal energy - the steam that has passed through the steam blades enters the network water heaters. This type of turbine is called the industrial heating or heating type of turbines. In the first case, steam extraction is provided for industrial purposes in the turbine. Complete with a generator, a steam turbine is a turbine unit.
Steam turbine types
Turbines are divided, depending on the direction in which the steam moves, into radial and axial turbines. The steam flow in radial turbines is directed perpendicular to the axis. Steam turbines can be one-, two- and three-case. The steam turbine is equipped with a variety of technical devices that prevent the ingress of ambient air into the casing. These are a variety of seals, which are supplied with water vapor in a small amount.
A safety regulator is located on the front section of the shaft, designed to turn off the steam supply when the turbine speed increases.
Characteristics of the main parameters of nominal values
· Turbine rated power- the maximum power that the turbine must develop for a long time at the terminals of the electric generator, with normal values of the main parameters or when they change within the limits specified by industry and state standards. A controlled steam extraction turbine can develop power above its nominal power if this is in accordance with the strength conditions of its parts.
· Turbine economic power- the power at which the turbine operates with the greatest efficiency. Depending on the parameters of live steam and the purpose of the turbine, the rated power can be equal to the economic power or more by 10-25%.
· Nominal temperature for regenerative feed water heating- the temperature of the feed water downstream of the last heater in the direction of the water.
· Rated cooling water temperature- the temperature of the cooling water at the inlet to the condenser.
gas turbine(fr. turbine from lat. turbo swirl, rotation) is a continuous heat engine, in the blade apparatus of which the energy of compressed and heated gas is converted into mechanical work on the shaft. It consists of a rotor (blades fixed on disks) and a stator (guide vanes fixed in the housing).
Gas having a high temperature and pressure enters through the turbine nozzle apparatus into the low pressure area behind the nozzle part, simultaneously expanding and accelerating. Further, the gas flow enters the turbine blades, giving them part of its kinetic energy and imparting torque to the blades. The rotor blades transmit torque through the turbine discs to the shaft. Useful properties of a gas turbine: a gas turbine, for example, drives a generator located on the same shaft with it, which is the useful work of a gas turbine.
Gas turbines are used as part of gas turbine engines (used for transport) and gas turbine units (used at thermal power plants as part of stationary GTUs, CCGTs). Gas turbines are described by the Brayton thermodynamic cycle, in which air is first adiabatically compressed, then burned at constant pressure, and then adiabatically expanded back to starting pressure.
Types of gas turbines
- Aircraft and jet engines
- Auxiliary power unit
- Industrial gas turbines for electricity production
- Turboshaft engines
- Radial gas turbines
- Microturbines
Mechanically, gas turbines can be considerably simpler than reciprocating internal combustion engines. Simple turbines may have one moving part: shaft/compressor/turbine/alternative rotor assembly (see image above), not including the fuel system.
More complex turbines (those used in modern jet engines) may have multiple shafts (coils), hundreds of turbine blades, moving stator blades, and an extensive system of complex piping, combustion chambers, and heat exchangers.
As a general rule, the smaller the motor, the higher the speed of the shaft(s) required to maintain the maximum linear speed of the blades. The maximum speed of the turbine blades determines the maximum pressure that can be reached, resulting in maximum power, regardless of engine size. The jet engine rotates at about 10,000 rpm and the micro-turbine at about 100,000 rpm.
The development of new types of gas turbines, the growing demand for gas compared to other types of fuel, large-scale plans of industrial consumers to create their own capacities cause a growing interest in gas turbine construction.
R The small generation market has great development prospects. Experts predict an increase in demand for distributed energy from 8% (currently) to 20% (by 2020). This trend is explained by the relatively low tariff for electricity (2-3 times lower than the tariff for electricity from the centralized network). In addition, according to Maxim Zagornov, a member of the general council of Delovaya Rossiya, president of the Association of small-scale power generation of the Urals, director of the MKS group of companies, small generation is more reliable than the network: in the event of an accident on the external network, the supply of electricity does not stop. An additional advantage of decentralized energy is the speed of commissioning: 8-10 months, as opposed to 2-3 years for the creation and connection of network lines.
Denis Cherepanov, co-chairman of the Delovaya Rossiya committee on energy, claims that the future belongs to its own generation. According to Sergei Yesyakov, First Deputy Chairman of the State Duma Energy Committee, in the case of distributed energy in the energy-consumer chain, it is the consumer, not the energy sector, that is the decisive link. With its own generation of electricity, the consumer declares the necessary capacities, configurations and even the type of fuel, saving, at the same time, on the price of a kilowatt of energy received. Among other things, experts believe that additional savings can be obtained if the power plant operates in cogeneration mode: the utilized thermal energy will be used for heating. Then the payback period of the generating power plant will be significantly reduced.
The most actively developing area of distributed energy is the construction of low-capacity gas turbine power plants. Gas turbine power plants are designed for operation in any climatic conditions as the main or backup source of electricity and heat for industrial and domestic facilities. The use of such power plants in remote areas allows you to get significant savings by eliminating the costs of building and operating long power lines, and in central areas - to increase the reliability of electrical and heat supply to both individual enterprises and organizations, and territories as a whole. Consider some gas turbines and gas turbine units that are offered by well-known manufacturers for the construction of gas turbine power plants in the Russian market.
General Electric
GE's wind turbine solutions are highly reliable and suitable for applications in a wide range of industries, from oil and gas to utilities. In particular, GE gas turbine units of the LM2500 family with a capacity of 21 to 33 MW and an efficiency of up to 39% are actively used in small generation. The LM2500 is used as a mechanical drive and a power generator drive, they work in power plants in simple, combined cycle, cogeneration mode, offshore platforms and pipelines.
For the past 40 years, GE turbines of this series have been the best-selling turbines in their class. In total, more than 2,000 turbines of this model have been installed in the world with a total operating time of more than 75 million hours.
Key features of the LM2500 turbines: lightweight and compact design for quick installation and easy maintenance; reaching full power from the moment of launch in 10 minutes; high efficiency (in a simple cycle), reliability and availability in its class; the possibility of using dual-fuel combustion chambers for distillate and natural gas; the possibility of using kerosene, propane, coke oven gas, ethanol and LNG as fuel; low NOx emissions using DLE or SAC combustion chambers; reliability factor - more than 99%; readiness factor - more than 98%; NOx emissions - 15 ppm (DLE modification).
To provide customers with reliable support throughout the life cycle of generating equipment, GE opened a specialized Energy Technology Center in Kaluga. It offers customers state-of-the-art solutions for the maintenance, inspection and repair of gas turbines. The company has implemented a quality management system in accordance with ISO 9001.
Kawasaki Heavy Industries
Japanese company Kawasaki Heavy Industries, Ltd. (KHI) is a diversified engineering company. An important place in its production program is occupied by gas turbines.
In 1943, Kawasaki created the first gas turbine engine in Japan and is now one of the world's recognized leaders in the production of gas turbines of small and medium power, having accumulated references for more than 11,000 installations.
With environmental friendliness and efficiency as a priority, the company has achieved great success in the development of gas turbine technologies and is actively pursuing promising developments, including in the field of new energy sources as an alternative to fossil fuels.
Having good experience in cryogenic technologies, technologies for the production, storage and transportation of liquefied gases, Kawasaki is actively researching and developing in the field of using hydrogen as a fuel.
In particular, the company already has prototypes of turbines that use hydrogen as an additive to methane fuel. In the future, turbines are expected, for which, much more energy-efficient and absolutely environmentally friendly, hydrogen will replace hydrocarbons.
GTU Kawasaki GPB series are designed for baseload operation, including both parallel and isolated network interaction schemes, while the power range is based on machines from 1.7 to 30 MW.
In the model range there are turbines that use steam injection to suppress harmful emissions and use DLE technology modified by the company's engineers.
Electrical efficiency, depending on the generation cycle and power, respectively, from 26.9% for GPB17 and GPB17D (M1A-17 and M1A-17D turbines) to 40.1% for GPB300D (L30A turbine). Electric power - from 1700 to 30 120 kW; thermal power - from 13,400 to 8970 kJ / kWh; exhaust gas temperature - from 521 to 470°C; exhaust gas consumption - from 29.1 to 319.4 thousand m3/h; NOx (at 15% O2) - 9/15 ppm for gas turbines M1A-17D, M7A-03D, 25 ppm for turbine M7A-02D and 15 ppm for turbines L20A and L30A.
In terms of efficiency, Kawasaki gas turbines, each in its class, are either the world leader or one of the leaders. The overall thermal efficiency of power units in cogeneration configurations reaches 86-87%. The company produces a number of GTUs in dual-fuel (natural gas and liquid fuel) versions with automatic switching. At the moment, three models of gas turbines are most in demand among Russian consumers - GPB17D, GPB80D and GPB180D.
Kawasaki gas turbines are distinguished by: high reliability and long service life; compact design, which is especially attractive when replacing equipment of existing generating facilities; ease of maintenance due to the split design of the body, removable burners, optimally located inspection holes, etc., which simplifies inspection and maintenance, including by the user's personnel;
Environmental friendliness and economy. The combustion chambers of Kawasaki turbines are designed using the most advanced techniques to optimize the combustion process and achieve the best turbine efficiency, as well as reduce NOx and other harmful substances in the exhaust. Environmental performance is also improved through the use of advanced dry emission suppression technology (DLE);
Ability to use a wide range of fuels. Natural gas, kerosene, diesel fuel, type A light fuel oils, as well as associated petroleum gas can be used;
Reliable after-sales service. High level of service, including a free online monitoring system (TechnoNet) with reports and forecasts, technical support by highly qualified personnel, as well as trade-in replacement of a gas turbine engine during a major overhaul (GTU downtime is reduced to 2-3 weeks), etc. .d.
In September 2011, Kawasaki introduced a state-of-the-art combustion chamber system that lowers NOx emissions to less than 10 ppm for the M7A-03 gas turbine engine, even lower than current regulations require. One of the company's design approaches is to create new equipment that meets not only modern, but also future, more stringent, environmental performance requirements.
The highly efficient 5 MW GPB50D gas turbine with a Kawasaki M5A-01D turbine uses the latest proven technologies. The plant's high efficiency makes it optimal for electricity and cogeneration. Also, the compact design of the GPB50D is particularly advantageous when upgrading existing plants. The rated electrical efficiency of 31.9% is the best in the world among 5 MW plants.
The M1A-17D turbine, through the use of an original combustion chamber design with dry emission suppression (DLE), has excellent environmental performance (NOx< 15 ppm) и эффективности.
The ultra-low weight of the turbine (1470 kg), the lowest in the class, is due to the widespread use of composite materials and ceramics, from which, for example, the impeller blades are made. Ceramics are more resistant to operation at elevated temperatures, less prone to contamination than metals. The gas turbine has an electrical efficiency close to 27%.
In Russia, by now, Kawasaki Heavy Industries, Ltd. implemented a number of successful projects in cooperation with Russian companies:
Mini-TPP "Central" in Vladivostok
By order of JSC Far Eastern Energy Management Company (JSC DVEUK), 5 GTUs GPB70D (M7A-02D) were delivered for Tsentralnaya TPP. The station provides electricity and heat to consumers in the central part of the development of Russky Island and the campus of the Far Eastern Federal University. TPP Tsentralnaya is the first power facility in Russia with Kawasaki turbines.
Mini-CHP "Oceanarium" in Vladivostok
This project was also carried out by JSC "DVEUK" for power supply of the scientific and educational complex "Primorsky Oceanarium" located on the island. Two GPB70D gas turbines have been delivered.
GTU manufactured by Kawasaki in Gazprom PJSC
Kawasaki’s Russian partner, MPP Energotekhnika LLC, based on the M1A-17D gas turbine, produces the Korvette 1.7K container power plant for installation in open areas with an ambient temperature range of -60 to + 40 °С.
Within the framework of the cooperation agreement, five EGTEPS KORVET-1.7K were developed and assembled at the production facilities of MPP Energotechnika. The areas of responsibility of the companies in this project were distributed as follows: Kawasaki supplies the M1A-17D gas turbine engine and turbine control systems, Siemens AG supplies the high-voltage generator. MPP Energotekhnika LLC manufactures a block container, an exhaust and air intake device, a power unit control system (including the SHUVGm excitation system), electrical equipment - main and auxiliary, completes all systems, assembles and supplies a complete power plant, and also sells APCS.
EGTES Korvet-1.7K has passed interdepartmental tests and is recommended for use at the facilities of Gazprom PJSC. The gas turbine power unit was developed by LLC MPP Energotechnika according to the terms of reference of PJSC Gazprom within the framework of the Scientific and Technical Cooperation Program of PJSC Gazprom and the Japan Natural Resources and Energy Agency.
Turbine for CCGT 10 MW at NRU MPEI
Kawasaki Heavy Industries Ltd., has manufactured and delivered a complete gas turbine plant GPB80D with a nominal power of 7.8 MW for the National Research University "MPEI" located in Moscow. CHP MPEI is a practical training and, generating electricity and heat on an industrial scale, provides them with the Moscow Power Engineering Institute itself and supplies them to the utility networks of Moscow.
Expansion of the geography of projects
Kawasaki, drawing attention to the advantages of developing local energy in the direction of distributed generation, proposed to start implementing projects using gas turbines of minimum capacity.
Mitsubishi Hitachi Power Systems
The model range of H-25 turbines is presented in the power range of 28-41 MW. The complete package of turbine production, including R&D and remote monitoring center, is carried out at the plant in Hitachi, Japan by MHPS (Mitsubishi Hitachi Power Systems Ltd.). Its formation falls on February 2014 due to the merger of the generating sectors of the recognized leaders in mechanical engineering Mitsubishi Heavy Industries Ltd. and Hitachi Ltd.
H-25 models are widely used around the world for both simple cycle operation due to high efficiency (34-37%), and combined cycle in 1x1 and 2x1 configuration with 51-53% efficiency. Having high temperature indicators of exhaust gases, the GTU has also successfully proven itself to operate in cogeneration mode with a total plant efficiency of more than 80%.
Many years of expertise in the production of gas turbines for a wide range of capacities and a well-thought-out design of a single-shaft industrial turbine distinguish the N-25 with high reliability with an equipment availability factor of more than 99%. The total operating time of the model exceeded 6.3 million hours in the second half of 2016. The modern GTP is made with a horizontal axial split, which ensures ease of maintenance, as well as the possibility of replacing parts of the hot path at the place of operation.
The countercurrent tubular-annular combustion chamber provides stable combustion on various types of fuel, such as natural gas, diesel fuel, liquefied petroleum gas, flue gases, coke oven gas, etc. pre-mixing of the gas-air mixture (DLN). The H-25 gas turbine engine is a 17-stage axial compressor coupled to a three-stage active turbine.
An example of reliable operation of the N-25 GTU at small-scale generation facilities in Russia is the operation as part of a cogeneration unit for the own needs of the JSC Ammonii plant in Mendeleevsk, the Republic of Tatarstan. The cogeneration unit provides the production site with 24 MW of electricity and 50 t/h of steam (390°C / 43 kg/cm3). In November 2017, the first inspection of the turbine combustion system was successfully carried out at the site, which confirmed the reliable operation of the machine components and assemblies at high temperatures.
In the oil and gas sector, N-25 GTUs were used to operate the Sakhalin II Onshore Processing Facility (OPF) site of the Sakhalin Energy Investment Company, Ltd. The OPF is located 600 km north of Yuzhno-Sakhalinsk in the landfall area of the offshore gas pipeline and is one of the company's most important facilities responsible for preparing gas and condensate for subsequent pipeline transmission to the oil export terminal and LNG plant. The technological complex includes four N-25 gas turbines, which have been in commercial operation since 2008. The cogeneration unit based on the N-25 GTU is maximally integrated into the OPF integrated power system, in particular, the heat from the exhaust gases of the turbine is used to heat crude oil for the needs of oil refining .
Siemens Industrial Gas Turbine Generator Sets (hereinafter referred to as GTU) will help to cope with the difficulties of the dynamically developing market of distributed generation. Gas turbines with a unit rated power from 4 to 66 MW fully meet the high requirements in the field of industrial combined energy production, in terms of plant efficiency (up to 90%), operational reliability, service flexibility and environmental safety, ensuring low life cycle costs and high return on investment. Siemens has more than 100 years of experience in the construction of industrial gas turbines and thermal power plants based on them.
Siemens GTUs ranging from 4 to 66 MW are used by small utilities, independent power producers (eg industrial plants) and the oil and gas industry. The use of technologies for distributed generation of electricity with combined generation of thermal energy makes it possible to refuse from investing in many kilometers of power lines, minimizing the distance between the energy source and the facility that consumes it, and achieve serious cost savings by covering the heating of industrial enterprises and infrastructure facilities through heat recovery. A standard Mini-TPP based on a Siemens GTU can be built anywhere where there is access to a fuel source or its prompt supply.
SGT-300 is an industrial gas turbine with a rated electric power of 7.9 MW (see Table 1), which combines a simple, reliable design with the latest technology.
Table 1. Specifications of SGT-300 for Mechanical Drive and Power Generation
|
Energy production |
mechanical drive |
||
|---|---|---|---|
|
7.9 MW |
8 MW |
9 MW |
|
|
Power in ISO |
|||
|
Natural gas / liquid fuel / dual fuel and other fuels on request; Automatic fuel change from main to reserve, at any load |
|||
|
Oud. heat consumption |
11.773 kJ/kWh |
10.265 kJ/kWh |
10.104 kJ/kWh |
|
Power turbine speed |
5.750 - 12.075 rpm |
5.750 - 12.075 rpm |
|
|
Compression ratio |
|||
|
Exhaust gas consumption |
|||
|
Exhaust gas temperature |
542°C (1.008°F) |
491°C (916°F) |
512°C (954°F) |
|
NOX emissions Gas fuel with DLE system |
|||
1) Electrical 2) Shaft mounted
Rice. 1. Structure of the SGT-300 gas generator
For industrial power generation, a single-shaft version of the SGT-300 gas turbine is used (see Fig. 1). It is ideal for combined heat and power (CHP) production. The SGT-300 gas turbine is an industrial gas turbine, originally designed for generation and has the following operational advantages for operating organizations:
Electric efficiency - 31%, which is on average 2-3% higher than the efficiency of gas turbines of lower power, due to the higher efficiency value, an economic effect on saving fuel gas is achieved;
The gas generator is equipped with a low-emission dry combustion chamber using DLE technology, which makes it possible to achieve levels of NOx and CO emissions that are more than 2.5 times lower than those established by regulatory documents;
The GTP has good dynamic characteristics due to its single-shaft design and ensures stable operation of the generator in case of fluctuations in the load of the external connected network;
The industrial design of the gas turbine provides a long overhaul life and is optimal in terms of organizing service work that is carried out at the site of operation;
A significant reduction in the building footprint, as well as investment costs, including the purchase of plant-wide mechanical and electrical equipment, its installation and commissioning, when using a solution based on SGT-300 (Fig. 2).
Rice. 2. Weight and size characteristics of the SGT-300 block
The total operating time of the installed fleet of SGT-300 is more than 6 million hours, with the operating time of the leading GTU 151 thousand hours. Availability/availability ratio - 97.3%, reliability ratio - 98.2%.
OPRA (Netherlands) is a leading supplier of energy systems based on gas turbines. OPRA develops, manufactures and markets state-of-the-art gas turbine engines around 2 MW. The key activity of the company is the production of electricity for the oil and gas industry.
The reliable OPRA OP16 engine delivers higher performance at lower cost and longer life than any other turbine in its class. The engine runs on several types of liquid and gaseous fuels. There is a modification of the combustion chamber with a reduced content of pollutants in the exhaust. The OPRA OP16 1.5-2.0 MW power plant will be a reliable assistant in harsh operating conditions.
OPRA gas turbines are the perfect equipment for power generation in off-grid electric and small-scale cogeneration systems. The design of the turbine has been under development for more than ten years. The result is a simple, reliable and efficient gas turbine engine, including a low emission model.
A distinctive feature of the technology for converting chemical energy into electrical energy in OP16 is the COFAR patented fuel mixture preparation and supply control system, which provides combustion modes with minimal formation of nitrogen and carbon oxides, as well as a minimum of unburned fuel residues. The patented geometry of the radial turbine and the generally cantilever design of the replaceable cartridge, including the shaft, bearings, centrifugal compressor and turbine, are also original.
The specialists of OPRA and MES Engineering developed the concept of creating a unique unified technical complex for waste processing. Of the 55-60 million tons of all MSW generated in Russia per year, a fifth - 11.7 million tons - falls on the capital region (3.8 million tons - the Moscow region, 7.9 million tons - Moscow). At the same time, 6.6 million tons of household waste are removed from Moscow outside the Moscow Ring Road. Thus, more than 10 million tons of garbage settle in the Moscow region. Since 2013, out of 39 landfills in the Moscow Region, 22 have been closed. They should be replaced by 13 waste sorting complexes, which will be commissioned in 2018-2019, as well as four waste incineration plants. The same situation occurs in most other regions. However, the construction of large waste processing plants is not always profitable, so the problem of waste processing is very relevant.
The developed concept of a single technical complex combines fully radial OPRA plants with high reliability and efficiency with the MES gasification / pyrolysis system, which allows for the efficient conversion of various types of waste (including MSW, oil sludge, contaminated land, biological and medical waste, waste woodworking, sleepers, etc.) into an excellent fuel for generating heat and electricity. As a result of long-term cooperation, a standardized waste processing complex with a capacity of 48 tons / day has been designed and is under implementation. (Fig. 3).
Rice. 3. General layout of a standard waste processing complex with a capacity of 48 tons/day.
The complex includes a MES gasification unit with a waste storage site, two OPRA gas turbines with a total electrical power of 3.7 MW and a thermal power of 9 MW, as well as various auxiliary and protective systems.
The implementation of such a complex makes it possible on an area of 2 hectares to obtain an opportunity for autonomous energy and heat supply to various industrial and communal facilities, while solving the issue of recycling various types of household waste.
The differences between the developed complex and existing technologies stem from the unique combination of the proposed technologies. Small (2 t/h) volumes of consumed waste, along with a small required area of the site, allow placing this complex directly near small settlements, industrial enterprises, etc., significantly saving money on the constant transportation of waste to their disposal sites. Complete autonomy of the complex allows you to deploy it almost anywhere. The use of the developed standard project, modular structures and the maximum degree of factory readiness of the equipment makes it possible to minimize the construction time to 1-1.5 years. The use of new technologies ensures the highest environmental friendliness of the complex. The MES gasification unit simultaneously produces gas and liquid fractions of fuel, and due to the dual-fuel nature of the OPRA GTU, they are used simultaneously, which increases fuel flexibility and reliability of power supply. The low demands of the OPRA GTU on fuel quality increase the reliability of the entire system. The MES unit allows the use of waste with a moisture content of up to 85%, therefore, waste drying is not required, which increases the efficiency of the entire complex. The high temperature of the exhaust gases of the OPRA GTU makes it possible to provide reliable heat supply with hot water or steam (up to 11 tons of steam per hour at 12 bar). The project is standard and scalable, which allows for the disposal of any amount of waste.
The calculations show that the cost of electricity generation will be from 0.01 to 0.03 euros per 1 kWh, which shows the high economic efficiency of the project. Thus, the OPRA company once again confirmed its focus on expanding the range of fuels used and increasing fuel flexibility, as well as focusing on the maximum use of "green" technologies in its development.
Power units - drives of electric generators for autonomous small thermal power plants can be diesel, gas piston, microturbine and gas turbine engines.
A large number of discussion and polemical articles have been written about the advantages of certain generating plants and technologies. As a rule, in disputes in the pen, either one or the other often remains in disgrace. Let's try to figure out why.
The determining criteria for choosing power units for the construction of autonomous power plants are the issues of fuel consumption, the level of operating costs, as well as the payback period for power plant equipment.
Ease of operation, level of maintenance and repair, and where to repair the power units are important factors in choosing power units. These issues are primarily related to the costs and problems that the owner of an autonomous power plant may subsequently have.
In this article, the author does not have a selfish goal to prioritize piston or turbine technologies. The types of power plants of power plants are more correct, it is best to select directly for the project, based on the individual conditions and technical specifications of the customer.
When choosing power equipment for the construction of an autonomous gas-fired CHP plant, it is advisable to consult with independent specialists from engineering companies that are already building turnkey power plants. An engineering company must have completed projects that can be viewed and visited with a tour. One should also take into account such a factor as the weakness and underdevelopment of the generating equipment market in Russia, where the real sales volumes, in comparison with developed countries, are small and leave much to be desired - this, first of all, is reflected in the volume and quality of offers.
Gas Reciprocating Plants vs. Gas Turbine Engines - Operating Costs
Is it true that the operating costs of a mini-CHP with reciprocating machines are lower than the operating costs of a power plant with gas turbines?
The cost of a major overhaul of a gas piston engine can be 30–350% of the initial cost of the power unit itself, and not of the entire power plant - during the overhaul, the piston group is replaced. Gas reciprocating units can be repaired on site without complex diagnostic equipment once every 7-8 years.
The cost of repairing a gas turbine plant is 30–50% of the initial investment. As you can see, the costs are about the same. Real, honest prices for gas turbine and piston units of comparable power and quality are also similar.
Capital repairs of the gas turbine plant due to its complexity are not carried out on site. The supplier must take away the spent unit and bring a replacement gas turbine unit. The old unit can only be restored to factory conditions.
You should always take into account compliance with the maintenance schedule, the nature of the loads and the operating modes of the power plant, regardless of the type of installed power units.
The question, which is often exaggerated, about the finickyness of the turbine to operating conditions, is associated with outdated information from forty years ago. Then "on the ground", in the drive of power plants, aircraft turbines "removed from the wing" of the aircraft were used. Such turbines with minimal changes adapted to work as the main power units for power plants.
Today, modern autonomous power plants use turbines of industrial, industrial design, designed for continuous operation with various loads.
The lower limit of the minimum electrical load, officially declared by manufacturers for industrial turbines, is 3–5%, but in this mode, fuel consumption increases by 40%. The maximum load of a gas turbine plant, in limited time intervals, can reach 110-120%.
Modern gas-piston installations have phenomenal efficiency, based on a high level of electrical efficiency. The “problems” associated with the operation of gas piston units at low loads are resolved positively even at the design stage. Design must be of high quality.
Compliance with the operating mode recommended by the manufacturer will extend the life of engine parts, thus saving money to the owner of an autonomous power plant. Sometimes, in order to bring the gas-piston machines to the nominal mode at partial loads, one or two electric boilers are included in the project of the thermal scheme of the station, which make it possible to provide the desired 50% load.
For power plants based on gas piston units and gas turbines, it is important to comply with the N + 1 rule - the number of operating units plus one more for the reserve. “N + 1” is a convenient, rational number of installations for the operating personnel. This is due to the fact that for power plants of any types and types it is necessary to carry out routine and repair work.
A company connected to the network can install only one unit and use its own electricity at cost, and during maintenance, be powered by the public electricity network, paying according to the meter. This is cheaper than "+1", but, unfortunately, is not always feasible. This is due, as a rule, to the lack of an electrical network in general, or to the incredible high cost of technical conditions for the connection itself.
Unscrupulous dealers of gas piston units and gas turbines, before selling the equipment to the buyer, as a rule, provide only prospectuses - general commercial literature and very rarely - accurate information about the full operating costs and technical regulations produced.
On powerful gas piston units, the oil does not need to be changed. With constant work, it is simply produced, not having time to age. Oil on such installations is constantly topped up. Such operating modes are provided for by a special design of powerful gas piston engines and are recommended by the manufacturer.
Engine oil waste is 0.25-0.45 grams per kilowatt produced per hour. Loss is always higher when the load is reduced. As a rule, a gas piston engine kit includes a special reservoir for continuous oil topping up, and a mini-laboratory for checking its quality and determining the replacement period.
Accordingly, oil filters or cartridges in them must also be replaced.
Since engine oil still burns out, piston units have a slightly higher level of harmful emissions into the atmosphere than gas turbine units. But since the gas burns completely and is one of the cleanest types of fuel, then talking about serious atmospheric pollution is just “stupid checkers”. A couple of old Hungarian Ikarus buses cause much more serious harm to the environment. To meet environmental requirements, when using reciprocating machines, it is necessary to build higher chimneys, taking into account the already existing MPC level in the environment.
Waste oil from gas piston units cannot simply be dumped on the ground - it requires disposal - this is an "expense" for the owners of the power plant. But you can earn money on this - specialized organizations buy used motor oil.
Many of us use engine oil in our piston engines. If the engine is serviceable, properly operated and refueled with normal fuel, then no financial cataclysms associated with its consumption occur.
The same is true for reciprocating power plants: - there is no need to be afraid of engine oil consumption, it will not ruin you, during the normal operation of modern high-quality gas piston installations, the costs for this article are only 2-3 (!) kopecks per 1 kW of generated electricity.
In modern gas turbine installations, oil is used only in the gearbox. Its volume can be considered insignificant. The replacement of gear oil in gas turbines is carried out on average once every 3-5 years, and its topping up is not required.
To carry out the service in full, a beam crane must be included in the set of a powerful gas piston installation. With the help of a beam crane, heavy parts of piston engines are removed. The use of a beam crane requires high ceilings in the machine rooms of the reciprocating power plant. For the repair of gas-piston installations of small and medium power, simpler lifting mechanisms can be dispensed with.
Gas piston power plants upon delivery can be equipped with various repair tools and devices. Its presence implies that even all critical operations can be carried out by qualified personnel on site. Virtually all repair work on gas turbines can be carried out either at the manufacturing plant or with the direct assistance of factory specialists.
Once every 3-4 months, the spark plugs need to be replaced. Replacing candles is only 1-2 (!) kopecks in the cost of 1 kW / h of own electricity.
Piston units, unlike gas turbine units, are liquid-cooled, respectively, the personnel of an autonomous power plant must constantly monitor the level of the coolant and carry out periodic replacement, and if it is water, then it is necessary to carry out its chemical preparation.
The above features of the operation of reciprocating units are absent in gas turbine plants. Gas turbine plants do not use such consumables and components as:
- motor oil,
- spark plug,
- oil filters,
- coolant,
- sets of high voltage wires.
But gas turbines cannot be repaired on site, and much higher gas consumption cannot be compared with the costs of operation and consumables for reciprocating units.
What to choose? Gas piston or gas turbine installations?
How do the power of power units of power plants and the ambient temperature correlate?
With a significant increase in ambient temperature, the power of the gas turbine installation decreases. But with a decrease in temperature, the electric power of a gas turbine, on the contrary, increases. Electrical power parameters, according to existing ISO standards, are measured at t +15 °C.
Sometimes an important point is the fact that a gas turbine plant is capable of delivering 1.5 times more free thermal energy than a piston unit of similar power. When using a powerful (from 50 MW) autonomous CHP in public utilities, for example, this can be of decisive importance when choosing the type of power units, especially with a large and uniform consumption of thermal energy.
On the contrary, where heat is not required in large quantities, but an emphasis is needed on the production of electrical energy, it will be more economically feasible to use gas piston plants.
The high temperature at the outlet of gas turbine plants makes it possible to use a steam turbine as part of a power plant. This equipment is in demand if the consumer needs to obtain the maximum amount of electrical energy with the same volume of gas fuel spent, and thus achieve high electrical efficiency - up to 59%. An energy complex of this configuration is more difficult to operate and costs 30-40% more than usual.
Power plants with steam turbines in their structure, as a rule, are designed for a fairly large power - from 50 MW and above.
Let's talk about the most important thing: gas piston units versus gas turbine power units - efficiency
The efficiency of the power plant is more than relevant - because it affects fuel consumption. The average specific consumption of gas fuel per 1 generated kW/h is much less for a gas-piston plant, and for any load mode (although long-term loads of less than 25% are contraindicated for piston engines).
The electrical efficiency of reciprocating machines is 40–44%, and that of gas turbines is 23–33% (in a steam-gas cycle, a turbine is capable of delivering an efficiency of up to 59%).
The steam-gas cycle is used at high power plants - from 50-70 MW.
If you need to manufacture a locomotive, an aircraft or a sea vessel, then one of the determining indicators is the efficiency factor (COP) of the power plant. The heat that is obtained during the operation of the engine of a locomotive, aircraft (or vessel) is not used and is released into the atmosphere.
But we are building not a locomotive, but a power plant, and when choosing the type of power units for an autonomous power plant, the approach is somewhat different - here it is necessary to talk about the completeness of the use of combustible fuel - the fuel utilization factor (FU).
Burning, the fuel does the main work - it rotates the generator of the power plant. The rest of the fuel combustion energy is heat that can and should be used. In this case, the so-called "overall efficiency", or rather, the fuel utilization factor (FUE) of the power plant will be about 80-90%.
If the consumer expects to use the thermal energy of an autonomous power plant in full, which is usually unlikely, then the coefficient of performance (COP) of an autonomous power plant is of no practical importance.
When the load is reduced to 50%, the electrical efficiency of the gas turbine decreases.
In addition, turbines require high gas inlet pressure, and for this, compressors (piston) are necessarily installed, and they also increase fuel consumption.
A comparison of gas turbine plants and gas piston engines as part of a mini-CHP shows that the installation of gas turbines is expedient at facilities that have uniform electrical and thermal needs with a power of more than 30-40 MW.
From the foregoing, it follows that the electrical efficiency of power units of various types has a direct projection on fuel consumption.
Gas piston units consume a quarter or even a third less fuel than gas turbine units - this is the main cost item!
Accordingly, with a similar or equal cost of the equipment itself, cheaper electrical energy is obtained from gas piston plants. Gas is the main expense item in the operation of an autonomous power plant!
Gas piston units vs. gas turbine engines - inlet gas pressure
Is it always necessary to have a high pressure gas pipeline when using gas turbines?
For all types of modern power units of power plants, the pressure of the supplied gas is of no practical importance, since the gas turbine unit always includes a gas compressor, which is included in the cost of the energy complex.
The compressor provides the required pressure performance of the gaseous fuel. Modern compressors are extremely reliable and low maintenance units. In the world of modern technologies, both for gas piston engines and gas turbines, it is only important to have the proper amount of gas fuel to ensure the normal operation of an autonomous power plant.
However, one should not forget that the booster compressor also requires considerable energy, consumables and maintenance. Paradoxically, reciprocating compressors are often used for powerful turbines.
Gas piston engines vs. gas turbine units - dual-fuel installations
It is often written and said that dual-fuel installations can only be piston. Is it true?
This is not true. All well-known manufacturers of gas turbines have dual-fuel units in their range. The main feature of the dual-fuel installation is its ability to work both on natural gas and diesel fuel. Due to the use of two types of fuel in a dual-fuel plant, a number of its advantages can be noted compared to mono-fuel plants:
- in the absence of natural gas, the unit automatically switches to diesel fuel;
- during transients, the unit automatically switches to diesel operation.
When entering the operating mode, the reverse process of switching to operation on natural gas and diesel fuel is carried out;
Do not forget about the fact that the first turbines were originally designed to operate on liquid fuel - kerosene.
Dual-fuel installations are still of limited use and are not needed for most autonomous CHP plants - there are simpler engineering solutions for this.
Gas piston units vs. gas turbine units - number of starts
What can be the number of starts of gas piston units?
Number of starts: a gas piston engine can start and stop an unlimited number of times, and this does not affect its engine life. But frequent starts-stops of gas-piston units, with loss of auxiliary power, can lead to wear of the most loaded units (turbocharger bearings, valves, etc.).
Due to the sharp changes in thermal stresses that occur in the most critical components and parts of the gas turbine hot duct during quick starts of the unit from a cold state, it is preferable to use a gas turbine plant for constant, continuous operation.
Gas piston engines of power plants against gas turbine plants - a resource before overhaul
What can be the resource of the installation before the overhaul?
The resource before overhaul is 40,000–60,000 working hours for a gas turbine. With proper operation and timely maintenance of a gas piston engine, this figure is also equal to 40,000–60,000 operating hours. However, there are other situations when overhaul occurs much earlier.
Gas piston units vs. gas turbine engines - capital investments and prices
What capital investments (investments) will be required in the construction of the power plant? What is the cost of building an autonomous power complex on a turnkey basis?
Calculations show that investments (dollar/kW) in the construction of a thermal power plant with gas piston engines are approximately equal to gas turbine plants. The Finnish thermal power plant WARTSILA with a capacity of 9 MW will cost the customer approximately 14 million euros. A similar gas turbine thermal power plant based on first-class units will cost $15.3 million.
Gas piston engines against gas turbine plants - ecology
How are environmental requirements met?
It should be noted that gas piston units are inferior to gas turbine units in terms of NO x emissions. Since engine oil burns out, piston units have a slightly higher level of harmful emissions into the atmosphere than gas turbine units.
But this is not critical: the SES asks for the background level according to the MPC at the location of the mini-CHP. After that, the dispersion is calculated so that the “additive” of harmful substances from the mini-CHP added to the background does not lead to exceeding the MPC. Through several iterations, the minimum height of the chimney is selected, at which the requirements of SanPiN are met. The addition from the plant of 16 MW in terms of NO x emissions is not so significant: at a chimney height of 30 m - 0.2 MPC, at 50 m - 0.1 MPC.
The level of harmful emissions from most modern gas turbine plants does not exceed 20-30 ppm, and in some projects this may have a certain value.
Piston installations during operation have vibrations and low-frequency noise. Bringing noise to standard values is possible, appropriate engineering solutions are simply needed. In addition to the dispersion calculation, when developing the “Environmental Protection” section of the project documentation, an acoustic calculation is made and it is checked whether the selected design solutions and the materials used meet the requirements of SanPiN in terms of noise.
Any equipment emits noise in a certain frequency spectrum. Gas turbine plants did not pass this cup.
Gas piston units vs. gas turbine engines - conclusions
With linear loads and compliance with the N + 1 rule, the use of gas piston engines as the main source of power supply is possible. As part of such a power plant, backup units and tanks are needed to store the second type of fuel - diesel.
In the power range up to 40-50 MW, the use of reciprocating motors at mini-CHPs is considered absolutely justified.
In the case of using gas piston units, the consumer can completely get away from external power supply, but only with a deliberate and balanced approach.
Piston installations can also be used as backup or emergency sources of electricity.
A certain alternative to piston installations is gas microturbines. True, the prices for microturbines “bite” a lot and amount to ~ $ 2500-4000 per 1 kW of installed power!
A comparison of gas turbine plants and gas piston engines as part of a mini-CHP shows that the installation of gas turbines is possible at any facilities that have electrical loads of more than 14-15 MW, but due to the high gas consumption, turbines are recommended for power plants of much larger capacity - 50-70 MW.
For many modern generating plants, 200,000 hours of operation is not a critical value, and subject to the scheduled maintenance schedule and the phased replacement of turbine parts subject to wear: bearings, injectors, various auxiliary equipment (pumps, fans), further operation of the gas turbine plant remains economically feasible. High-quality gas piston units today also successfully overcome 200,000 hours of operation.
This is confirmed by the modern practice of operating gas turbine / gas piston plants around the world.
When choosing the power units of an autonomous power plant, expert advice is needed!
Expert advice and supervision are also necessary in the construction of autonomous power plants. To solve the problem, we need an engineering company with experience and completed projects.
Engineering allows you to competently, unbiasedly and objectively determine the choice of the main and auxiliary equipment for the selection of the optimal configuration - the configuration of your future power plant.
Qualified engineering allows you to save significant money for the customer, and this is 10-40% of the total cost. Engineering from professionals in the power industry avoids costly mistakes in the design and selection of equipment suppliers.
A gas turbine is an engine in which, in the process of continuous operation, the main organ of the device (the rotor) converts (in other cases, steam or water) into mechanical work. In this case, the jet of the working substance acts on the blades fixed around the circumference of the rotor, setting them in motion. In the direction of the gas flow, turbines are divided into axial (gas moves parallel to the axis of the turbine) or radial (perpendicular movement relative to the same axis). There are both single and multi-stage mechanisms.
A gas turbine can act on the blades in two ways. Firstly, it is an active process, when gas is supplied to the working area at high speeds. In this case, the gas flow tends to move in a straight line, and the curved blade part standing in its way deflects it, turning itself. Secondly, it is a reactive type process, when the gas supply rate is low, but high pressures are used. type in its pure form is almost never found, because in their turbines it is present which acts on the blades along with the reaction force.
Where is the gas turbine used today? The principle of operation of the device allows it to be used for drives of electric current generators, compressors, etc. Turbines of this type are widely used in transport (ship gas turbine installations). Compared to steam counterparts, they have a relatively small weight and dimensions, they do not require the arrangement of a boiler room, a condensing unit.
The gas turbine is ready for operation quite quickly after start-up, develops full power in about 10 minutes, is easy to maintain, requires a small amount of water for cooling. Unlike internal combustion engines, it does not have inertial effects from the crank mechanism. one and a half times shorter than diesel engines and more than twice as light. The devices have the ability to run on low quality fuel. The above qualities make it possible to consider engines of this kind of particular interest for ships on and hydrofoils.
The gas turbine as the main component of the engine has a number of significant disadvantages. Among them, they note high noise, less than diesel engines, efficiency, short life at high temperatures (if the gas medium used has a temperature of about 1100 ° C, then the turbine can be used on average up to 750 hours).
The efficiency of a gas turbine depends on the system in which it is used. For example, devices used in the power industry with an initial temperature of gases above 1300 degrees Celsius, from air in the compressor no more than 23 and no less than 17, have a coefficient of about 38.5% during autonomous operations. Such turbines are not very widespread and are mainly used to cover load peaks in electrical systems. Today, about 15 gas turbines with a capacity of up to 30 MW operate at a number of thermal power plants in Russia. At multi-stage plants, a much higher efficiency index (about 0.93) is achieved due to the high efficiency of structural elements.
