At the beginning of 2023, the Russian army aimed its "Caliber" cruise missiles at a factory on the outskirts of Mykolaiv, Ukraine, and intensively bombed almost every building here with unlimited firepower. This plant is one of the most important military legacies left by the Soviet Union to Ukraine, the Dawning Machinery Design Bureau, which has a prominent position in the field of Soviet ships, from the 055 destroyer cruising in the South China Sea to the "Indomitable class" frigate deployed in the Russian Arctic Ocean, from the hot Indian Ocean to the dead silence of the Black Sea, various types of gas turbines developed and produced by the Dawning Design Bureau are widely equipped with naval ships around the world.
Founded in 1946, Shuguang Machinery Design Bureau officially began to design and manufacture various types of gas turbines from 1954, Shuguang Design Bureau has developed and delivered four generations of various types of gas turbines, with a power range of 2.5 MW to 110 MW, and has delivered more than 3,000 gas turbines, accounting for about one-third of the world's gas turbine number, and is one of the world's three major marine gas turbine manufacturers, second only to General Electric of the United States and Rolls-Royce of the United Kingdom. But with the outbreak of the Russia-Ukraine conflict in 2022, the gas turbine design bureau, which is already over half a hundred years old, may have come to the end of history......
China's gas turbine has long been extremely backward, through the imitation of Soviet-style small marine gas turbines, China's gas turbine development from the 50s of the last century started hard, but in the basic theory of the internal flow of turbomachinery, the Chinese are extremely important pioneers.
We know that aviation turbofan engines and gas turbines are in the same vein, and the theoretical basis of the internal flow of early turbomachinery is the theory of flow around the wing in aeronautical engineering, but the internal flow of the turbomachinery is far more complex than the flow around the wing: not only the shape of the blades is complex, the number is large, the interaction between dynamic and static blades, the flow presents unsteady, three-dimensional viscous flow characteristics, and the fluid flow velocity is divided into subsonic velocity, supersonic velocity, transonic velocity and so on. Until the end of the 40s of the 20th century, the isolated blade model was used in the industry. The model can only calculate the change of inlet and outlet flow parameters at the average radius of the blade, cannot calculate the torsion and bending of the blade, and does not consider the interaction between the blades.
Wu Zhonghua, the founder of continental thermophysics, the first director of the Institute of Engineering Thermophysics of the Chinese Academy of Sciences, and the founder of the Department of Engineering Thermophysics of the University of Science and Technology of China, pioneered the ternary flow theory of impeller machinery, and is an outstanding scientist with outstanding achievements and international influence.
After graduating from Southwest Associated University in 1940, Wu Zhonghua went to the United States to study and received a doctorate degree in internal combustion engines from the Massachusetts Institute of Technology. In 1947, he joined the Lewis Jet Propulsion Center of the American Aeronautical Advisory Committee, the predecessor of NASA, as a research scientist. In 1950 he published the paper "Application of Radial Equilibrium Conditions to the Design of Axial Flow Compressors and Turbines", and then published a series of papers to create the internationally recognized general theory of ternary flow in turbomachinery. He made two subversive breakthroughs: one was to abandon the accepted method of treating blades as isolated airfoils at that time, and to replace the viscous options that were difficult to calculate with entropy gradients, and to propose the Wu equation; second, to abandon the analytical solution method advocated by the fluid mechanics community at that time, and decompose the complex three-dimensional space flow into several simple and reasonable two-dimensional calculations, making it possible to use computers to solve numerical problems. In the mid-60s, he took this theory to a new level by proposing a system of fundamental equations for ternary flow in turbomachinery using arbitrary non-orthogonal curve coordinates and corresponding non-orthogonal velocity components. So far, the ternary flow theory of turbomachinery is still the theoretical basis and powerful tool for the design and analysis of contemporary advanced turbomachinery, and the application scope of its theory is expanding day by day, in addition to aero engines, gas turbines, steam turbines, pumps, etc., this theory is also applied in the design of hydraulic turbines of the Three Gorges Project in mainland China.
The ternary flow theory proposed by Wu Zhonghua was extremely cutting-edge, but the computer power was too poor at that time, so it was not used in the engineering research and development of turbomachinery for a long time. When the first generation of large bypass ratio turbofan engine came out at the end of the 60s of the last century, the ternary flow theory and method had not yet been applied, and the power only appeared in the 80s. Of course, the development of modern aero engines and gas turbines depends not only on the progress of science and technology such as theory and method, design and experiment, but also on the breakthrough of engineering technology such as materials and manufacturing.
Therefore, China's exploration of ship gas turbines is destined to be difficult. In 1967, inspired by the successful development of the "Olympus" ship gas turbine by the British, China also decided to develop a high-power ship gas turbine on the basis of the turbojet-8 jet engine of the H-6, the air flow rate and maximum thrust of the turbojet-8 are comparable to the prototype of the "Olympus" ship gas turbine of the British Rolls-Royce company, that is, the "Olympus" turbojet engine installed on the "Vulcan" strategic bomber and the "Concorde" supersonic passenger aircraft, but the thrust-to-weight ratio is obviously backward, and the fuel consumption rate is much higher. More than 80 modifications have been made to the "Turbojet-8 modification" ship gas turbine to adapt to the harsh environment of the ship's operation at sea, but the power is not up to standard and the service life is only 200 hours, so it cannot be equipped for production.
At the same time, China's desire for large surface warships is growing day by day. You must know that the first batch of destroyers equipped by China were four obsolete Type 07 destroyers imported from the Soviet Union in 1954 that had been in service for more than ten years, with a full load displacement of 2,100 tons, which can be called scrap copper and rotten iron, and the asking price was equivalent to 17 tons of gold at that time. But for the Chinese Navy, even such "scrap metal" will play a huge role in improving the overall strength of the navy. Until the early 70s of the last century, these 4 warships were still the largest tonnage surface combat ships of the Chinese Navy, known as the "Four King Kongs", and they were in service until the 90s of the last century before they were decommissioned!
In February 1968, according to the report of the "Proposal on the Construction of Ocean-going Escort Ships", our army issued the task of carrying out the demonstration of the tactical technology and scheme of large artillery missile ships, and determined the design code 055. In the special era of disturbances and in full swing at that time, the progress of the 055 program was very slow, but it finally received the attention of the party and state leaders. In June 1970, Premier Zhou Enlai made the following instructions on the development of large destroyers: "If the combat mission of the large missile destroyer 055 is only in the near sea, it can be mainly sea-to-air, taking into account anti-submarine, and it seems that more consideration should be given to the anti-submarine weapons for ocean voyages. Please consider whether it is appropriate or not!".
With Nixon's lightning visit to China in 1972 and the setting of the tone of NATO's action of "uniting China to resist the Soviet Union", China began frequent exchanges with the United States, Britain, France, Germany and other major NATO scientific and technological powers, with the intention of introducing some advanced technologies and equipment that could not be solved at home for the time being. At that time, China was called a non-staff ally of NATO, so what could not be sold? In 1972, Sir Stanley Hooke, a well-known engine expert of the British Rolls-Royce Company, came to Shenyang Liming Factory to give lectures and visits, and even did not hesitate to help solve the problem of the domestically produced turbojet 7 engine. The military version of the "Spey" 202 was first proposed by the British to China, and China did not have the luxury of buying the military version. In the end, Zhou Enlai withstood the huge pressure, personally made the decision, and spent 500 million pounds to introduce 50 "Spey" MK202 military turbofan engines and production licenses from the United Kingdom.
At that time, Britain's aero engines and gas turbines were at the forefront of the world, and the British Navy even made a decision as early as 1968 that shocked the navies of the world's major countries: since then, the Royal Navy will design and build large and medium-sized surface ships with gas turbines as propulsion units. Rolls-Royce developed the earliest G6, Olympus, Poseidon and other gas turbines, and then the WR21 gas turbine has an output of up to 25.2 megawatts, while the MT30 gas turbine is currently the world's largest gas turbine, with a power of 36 megawatts, about 50,000 horsepower, and a maximum power of 40 megawatts, derived from the Trent 800 turbofan engine of Rolls-Royce, which is equipped with an aero engine for the Boeing 777 passenger aircraft, with a thermal efficiency of more than 40% The MT30 is proud of its world's strongest power while maintaining a very slim stature! Its core turbine power unit weighs only 9.6 tons, and even with the fully installed box, it weighs only 21 tons! This is tantamount to the existence of a small Nezha in the face of a steam turbine of hundreds of tons, which can not only obtain abundant power to overturn the river and the sea, but also save a large amount of space for weapons and equipment or living facilities.
The Spey we introduced was specially developed for the F-4K/F-4M Phantom fighter used by the British Navy and Air Force. "Spey" is still "into the sky into the sea", "aviation development and gas turbine" is the most successful case, the "Ocean Spey" ship gas turbine single power of 19.5 megawatts, the main power of this gas turbine as the main force of the warships are also numerous, including the British 22 type "broadsword" class, 23 type "Duke" class, the Netherlands' "Karel Dolman" class frigate, "Seven Provinces" class air defense destroyer, and the largest user is the Japanese Maritime Self-Defense Force, since the 80s of the last century, "Asagiri" class, "Murayu" class, "Gao BoThe "Spey" class and the "Asahi" class general-purpose destroyers, which were commissioned only a few years ago, as well as the "Flag Wind" class air defense destroyers and the "Abukuma"-class frigates, all used the "Spey", and it was not until the "Asahi" class destroyers, which were in service in the past two years, that they were replaced by the American LM2500.
With the introduction of the "Spey" engine, the development of the 055 large missile destroyer was also launched. In March 1976, the Sixth Ministry of Machinery Industry and other relevant units accepted the task of developing the 055 large missile destroyer. The design indicators of the ship are as follows: displacement of nearly 8,000 tons; equipped with sea-to-sea artillery systems and missile systems; equipped with anti-aircraft artillery systems and missile systems; equipped with complete anti-submarine systems such as rocket-depth bombs, rocket-assisted torpedoes, conventional anti-submarine torpedoes, and anti-submarine helicopters; equipped with sea-to-sea radars, anti-air early warning radars, and three-coordinate radars; The diesel-combustion alternating power unit composed of two gas turbines with a single power of 23,530 kilowatts and two 18VE390ZC diesel engines with a single power of 8,824 kilowatts is used to drive two fixed-pitch propellers for propulsion.
It is obvious that in the 70s of the last century, many of the equipment, especially gas turbines, were equipment that had not yet been developed in China, and the tactical and technical requirements far exceeded the actual production level of China at that time. In 1981, the 055 large missile destroyer had to be withdrawn from the official type study and reclassified as a preliminary study. At this point, the 055 large missile destroyer program, which once pinned the dream of the Chinese Navy on blue water, has come to an end.
Therefore, solving the basic power equipment has become a top priority, and the development and mass production of the localized turbofan 9 of "Spey", which the country has spent hundreds of millions of pounds to introduce, has become the top priority. Vice Premier Wang Zhen inspected Xi'an Aero Engine Company three times to take care of the trial production work, and Vice Minister of Aviation Mo Wenxiang also led a team to stay. In 1980, the turbofan 9 went to the United Kingdom to achieve successful test under complex conditions and passed the cyclic fatigue strength test. Representatives of China and Britain signed the successful assessment document of the turbofan 9 engine, and China's "Spey" engine was finally born.
"Spey" has a complex structure, many blades, many precision parts, many thin-walled welded parts, many pipe fittings with complex shapes, and many difficult-to-process materials. Through trial production, the engine factory mastered 13 advanced technologies with the world's advanced level at that time, such as metal spraying, vacuum heat treatment, pipe trajectory welding, vacuum brazing, CNC pipe bending, and large-scale casing electrolytic processing. "Spey Technology" and "Spey People" have greatly promoted the technical level of Chinese engines.
After the "Spey" gained a foothold in China, the British company Rolls-Royce also actively promoted the gas turbines of the "Olympus" and "Ocean Spey" ships to China, and the Americans could not sit still.
At that time, China and the United States were in a honeymoon period, and military exchanges were closer. On 5 November 1986, Admiral Lyons, commander of the US Pacific Fleet, led a total of 894 officers and men from the cruiser USS Reeves, the destroyer USS Aldendorf, and the guided-missile frigate USS Lenzi, on a week-long goodwill visit to Qingdao, China. This is the first visit of the US Navy since the founding of the People's Republic of China, and there is a very important part of it, that is, the two sides send officers and soldiers to visit each other's warships. After boarding the warship of the world's largest navy, the officers and men of the People's Liberation Army (PLA) were amazed by the advanced missiles, radar systems, weapon systems, and advanced design. At that time, the Chinese Navy was only able to get its hands on the Type 051 missile destroyer, and the Type 453 steam turbine was still used, which was far from the ships of the US Navy in terms of tonnage, design concept, weapon system and living environment. Admiral Lyons, commander of the US Navy's Pacific Fleet, commented after visiting the Type 051 destroyer: This is the best preserved antique I have ever seen, which made the Chinese officers and men present embarrassed for a while.
At that time, General Dynamics of the United States was competing with the British for the world ship gas turbine market, and the most successful ship gas turbine in history: the LM2500 gas turbine, squeezed the British gas turbine out of the Chinese market in one fell swoop.
The LM2500 gas turbine is a modified gas turbine based on the TF39 turbofan engine of the C-5 "Galaxy" heavy transport aircraft, which has been used in more than 700 ships of the United States Navy since the 70s of the last century, including the Spruance destroyer, the Perry-class frigate, the Huangfeng amphibious assault ship, the Ali Burke destroyer and the Ticantroga cruiser. LM2500 has also almost occupied the "half of the world's navy", with a total installed capacity of more than 5,000 units, and is used by various ships of the navies of 33 countries in the world.
From the original 25,500 horsepower to 47,370 horsepower, the LM2500 spans two power classes with an overhaul life of up to 30,000 hours. The LM2500 series gas turbine is a twin-shaft gas turbine consisting of a gas generator and a 6-stage power turbine. The gas generator includes a 17-stage compressor, a dry low-emission burner and a 2-stage high-pressure turbine. The compressor is on the same high-speed shaft as the high-pressure turbine that drives it, and the power turbine is on a separate low-speed shaft. The first 7 stages of the compressor can be adjusted by hydraulic actuators to improve the efficiency of the gas turbine under different loads and prevent surge in the compressor.
The American GM LM2500 is superior to the British counterpart in terms of comprehensive performance, and in the mid-80s, the United States promised to gradually transfer the technology of the LM2500, so that China can obtain the ability to copy and produce the LM2500, so China decided to install the LM2500 gas turbine on the Type 052 destroyer. But in 1989, when the construction of the lead ship of Type 052 "Harbin" began, the situation changed significantly. The West has restarted the ban on sales to China, and the introduction of the LM2500 has been blocked, and China has only received four finished LM2500 and one LM2500 prototype for training and experiments. In the end, four LM2500s could only be installed on two Type 052 destroyers "Harbin" and "Qingdao", and it was not until 1994 that the two ships were put into service successively, and the Chinese Navy could be regarded as having a modern destroyer in the true sense.
After the United States cut off the supply of gas turbines, the construction of the Type 052 destroyer had to be stopped, and there were no gas turbines available for a long time afterward. Including the subsequent construction of the 051B Shenzhen ship, the 051C first ship Shenyang, the 051C Shijiazhuang ship, and the successive introduction of four modern-class destroyers, namely the Hangzhou ship, the Fuzhou ship, the Taizhou ship and the Ningbo ship, all use steam turbines, which are nicknamed the "Seven Sons of the Whole Steam".
It was not until 11 years later, on May 23, 2002, when the lead ship of the Type 052B destroyer "Guangzhou" was launched, that the Chinese Navy used the Ukrainian UGT-25000 gas turbine as a power scheme on the destroyer. It was not until October 28, 2010 that the Type 052C missile destroyer "Changchun" was launched, and it was officially self-sufficient and no longer dependent on imports. It took almost 20 years for the Chinese Navy to be equipped with gas turbines for the first time to achieve localization.
Therefore, in the 80s of the last century, when the Ukrainian UGT25000, commonly known as the "dog head", had not yet been introduced, the "Spey Aeronautical Reform" ship gas turbine GD-1000 was the focus of research by the mainland's industrial sector. Entrusted by Vice Premier Wang Zhen, Wu Zhonghua actively proposed the modification plan of changing the "Spey" engine into a shipboard and gas-steam combined cycle device. At that time, China's industrial base was weak, and it was not until 1993 that the GD-1000 prototype passed the performance appraisal, with a power of only 13,000 horsepower and no equipment value.
There is no doubt that China's gas turbines have been able to achieve localization in 20 years, and the biggest credit is the introduction of the UGT-25000 gas turbine.
During the Soviet era, Ukraine was the main place for the development and production of ship power, mainly for the development and production of gas turbines, while Russia was mainly for the production of steam turbines and nuclear power. The development of the UGT-25000 gas turbine began in 1985, by the beginning of the 90s, the main research and development work was completed, and after the collapse of the USSR, Ukraine inherited the full set of technologies for the UGT-25000 gas turbine.
In 1993, Ukraine exported 10 UGT-25000 gas turbines to China and transferred related technologies. The first batch of gas turbines were assembled on the famous "Jiangnan Four Heroes", namely two Type 052B Guangzhou and Wuhan ships, and two Type 052C missile destroyers Lanzhou and Haijiao. The air flow, volume and weight of the UGT-25000 are greater than those of the American LM2500, and cannot be directly used on Type 052 destroyers. To this end, the mainland specially designed the Type 052B destroyer to realize the UGT-25000 loading, and at the same time greatly improved the comprehensive combat capability with the help of Russian and Ukrainian technology, for which the lead ship of the Type 052B destroyer "Guangzhou" was called "China's first ship" at the beginning of the launch.
In 1998, the localization process of gas turbines began, involving three units: the 703rd Research Institute under China Shipbuilding Industry Corporation, Xi'an Aero Engine Company and Harbin Steam Turbine Company. Produced by the 703 Research Institute, the technical drawings of its procurement are shared with Xi'an Aero Engine Company. Combined with the localization of "Spey" and the experience of using the LM2500 gas turbine, the experts made a series of improvements.
In 2004, the first domestic model was completed, named GT-25000, and 60% localization was realized. In 2011, GT25000 made a lot of adaptation improvements to the high-temperature, high-humidity and high-salt marine environment in the South China Sea, with a localization rate of 98.1%, and was recognized by the Navy for the actual use of escort in the Gulf of Aden carried by the Wuhan ship. Later, Xi'an Aero Engine Company, which participated in the localization of GT-25000, launched the QC-280. But in the end, the Chinese Navy insisted on using the GT-25000 as the power of warships, and the QC-280 was mainly used in industrial fields such as power generation and industrial gas compression.
With the mass production of the domestic GT-25000 gas turbine, the Chinese Navy officially began a shipbuilding frenzy.
The GT-25000 is a perfect match with the 055 destroyer, which is the first surface combat ship of the Chinese Navy to adopt COGAG all-fire combined power. 055 is installed with 4 GT25000, two in parallel. When sailing at high speeds, 4 gas turbines are at full firepower, and when sailing at low speeds, only 1 or 2 gas turbines need to be turned on, which is very flexible to use.
The GT-25000 is rated at 26.7 megawatts, or about 36,000 horsepower, and its thermal efficiency is 36.5%. The 055 destroyer is installed with 4 units, with a total power of 106.8 megawatts, equivalent to 145,000 horsepower, which can make the 055 easily soar to 33~34 knots, which is currently the fastest large destroyer in the world.
The U.S. Navy's newest Arleigh Burke 3 destroyer has a full load displacement of 9,550 tons, uses four LM2500 gas turbines, and has a total power of 100,500 horsepower, which is the highest efficiency ratio among the active ships of the U.S. Navy, but it is still a younger brother compared to the 055. The "Zumwalt" class destroyer, with a full load displacement of 14,560 tons, uses 2 MT-30 gas turbines + 2 auxiliary gas turbine generators, with a total power of 105,000 horsepower, but the total power is only two-thirds of that of 055.
The British "Queen Elizabeth" class aircraft carrier, with a displacement of more than 65,000 tons, uses two British Royce MT30 gas turbines, two 16V38B diesel engines and two 12V38B diesel engines, with a total power of only 147,000 horsepower, which is about the same as a Chinese 055 drive.
The French nuclear-powered aircraft carrier Charles de Gaulle has a full load displacement of about 42,000 tons, uses two K-15 nuclear reactors with the same K-15 nuclear reactors as the Triumph-class strategic nuclear submarines, and has an output of only 76,200 horsepower. The power of the 055 destroyer is equivalent to the power of 2 French nuclear aircraft carriers "Charles de Gaulle".
The surging power provides great support and upgrade potential for the 055 destroyer's tactical maneuvering, onboard electronics, and future directed energy weapons.
We know that the main advantage of gas turbines is that the energy density is extremely large, and at the same power, the volume and weight are only 1/3 to 1/5 of the diesel engine, and less than 1/10 of the steam turbine. When the throttle changes, the change in gas volume can act on the output shaft in near real time, and the acceleration is far superior not only to the steam turbine, but also to the best ship diesel engines. Moreover, as a continuous rotary type of heat engine, its noise and vibration are far less than that of diesel engines, and also better than those of steam turbines, which are also continuous rotary types.
Of course, gas turbines and aero engines are known as "the most difficult mechanical equipment in the world to manufacture", and in addition to the theory of quantum mechanics, almost all other mechanical theories are used, and the most cutting-edge manufacturing technology and materials are also needed. The main structure of the gas turbine consists of three parts: compressor, combustion chamber and gas turbine. The air is sucked into the compressor from the outside and compressed into high-pressure gas, and then fully mixed with the injected fuel in the combustion chamber to produce high-temperature and high-pressure gas, and the high-speed flowing gas enters the turbine end to drive the impeller and the load rotor to rotate at high speed, in addition to compensating for the work required by the compressor to rotate the compressed air, most of the remaining energy is converted into shaft power.
GT25000 with axial air intake, axial compressors can connect many compressor blades in series to achieve multi-stage pressurization. It consists of a 9-stage axial low-pressure compressor with adjustable first 3-stage guide vanes and a 9-stage axial high-pressure compressor with a pressure ratio of 20. A small part of the compressed air enters the combustion chamber for combustion, and most of it is used for cooling and sealing.
The GT25000 combustion chamber structure is a counter-current ring tube dry type with low emissions, and there are 16 flame barrels, which are connected to each other for cross-ignition. The front end of the flame barrel is equipped with a burner, and the middle and rear sections are coated with ceramic thermal barriers and accompanied by cooling air vents. After ignition, the temperature of the heated side of the inner wall of the burning barrel is nearly 1,600 degrees Celsius, while the temperature on the other side is only more than 600 degrees Celsius, and the wall of the barrel about a few centimeters thick is separated by a high temperature of nearly 1,000 degrees! After a long time of baking at such a temperature, most of the metals will melt, and even the nickel-rhenium superalloy, which is known as the king of aviation metals, is not spared. The gases in the combustion chamber also continue to impact the combustion chamber at tornado-like speeds, and the operating conditions are far harsher than those of a rocket engine. Therefore, the thermal barrier coating on the wall of the combustion chamber is better than the thermal insulation ceramic on the space shuttle, after all, the space shuttle replaces the damaged thermal insulation ceramic before each takeoff, while the thermal barrier coating in the gas turbine needs to be overhauled after thousands of hours of operation.
The next part was even more challenging. The hot gases after combustion push the blades in the turbine to rotate. The first-stage blades in the turbine zone must not only withstand temperatures of nearly 1,600 degrees, but also rotate at the speed of sound and withstand centrifugal forces equivalent to 10,000 times their own weight. The turbine blades of the gas turbine are made of a single crystal made of a special alloy and then coated with a special ceramic. But this is not enough, part of the air drawn in by the compressor will be transported to the bottom of the blade, and then sprayed out of the small holes on the surface of the blade through the channels in the blade, forming a thin layer of air cooling film on the surface of the blade. This way the leaves can tolerate the temperature of melting rocks!
Therefore, it is extremely important to improve the temperature resistance level and comprehensive performance of the blade, and the preparation process has gradually developed from traditional investment precision casting to advanced directional crystallization and single crystal preparation technology. The aerodynamic characteristics also need to be continuously optimized and iterative, using Wu Zhonghua's ternary flow theory, coupled with supercomputers, to further improve the performance of compressors and turbine components, and to study controllable vortex design, free vortex design, swept bending and torsion blade technology, multi-arc blade type, controllable diffusion blade type, gap flow control and other technologies to reduce various aerodynamic losses. In terms of cooling and thermal barrier coating technology and process, advanced advanced cooling technology of porous laminates, electron beam physical vapor deposition thermal barrier coating and process are adopted.
Finally, in order to reduce the infrared radiation characteristics of the ship and resist the 3~5μm point source identification and 8~14μm band surface source identification of the infrared guidance of anti-ship missiles, it is necessary to design the exhaust pipe of the gas turbine in the form of exhaust emission, and use the exhaust kinetic energy of the gas turbine to induce external cold air to achieve exhaust cooling. Or the active wet exhaust cooling, the high-temperature exhaust gas is cooled by water spray and then discharged from the side or tail.
In addition, the use of advanced complex cycle gas turbines represents the future direction, which is expected to further improve the thermal efficiency of ship gas turbines, including intercooling, recuperation, intercooling and reheating ICR, steam reinjection, gas-steaming combined, moist air turbine HAT, fuel cell hybrid and other cycle gas turbines. Among them, the intercooled circulating gas turbine adds an intercooler between the low-pressure compressor and the high-pressure compressor, and the air enters the intercooler for cooling after being compressed by the low-pressure compressor, which not only reduces the air temperature entering the inlet of the high-pressure compressor, reduces the compression work of the high-pressure compressor, but also reduces the outlet temperature of the high-pressure compressor, and the lower inlet temperature of the combustion chamber can simplify the combustion chamber structure. There is no precedent for the application of intercooled cycle gas turbines on foreign ships, so it can be called "high-power marine gas turbines with Chinese characteristics".
It can be seen that the mastery of the aerodynamics of the gas turbine compressor, the material, process and cooling protection of the high-temperature parts of the combustion chamber, and the design of the flow channel of the turbine cooling air flow are all cutting-edge technologies. So there are only five countries in the world that have full-fledged military high-power marine gas turbines, namely the United Kingdom, the United States, China, Ukraine and Russia. As for France, Japan, Germany, Italy and other industrial powers, they cannot design and manufacture high-power military gas turbines as a whole, and they have only made achievements in the field of low-power marine or industrial gas turbines.
There is another reality that cannot be ignored: although Russia has made great progress in the field of gas turbines in recent years, the power of a single gas turbine of the М-90Р type is less than 30,000 horsepower, so Russia can only be regarded as a new student from scratch in the field of large marine gas turbines! In May 2023, Russia decided to purchase 20 GT-25000 improved CGT25-D gas turbines from China for use in the Arctic-2 LNG project, a major breakthrough in the mainland's large-scale gas turbine exports.
In the next few years, the GT25000 family is also about to usher in the largest improvement, the largest rated output of the new members, a type of advanced intercooled cycle marine gas turbine has entered the assessment and testing stage, breaking through the advanced intercooled cycle gas turbine overall aerodynamic and structural design, on-board compact high-efficiency and low-loss intercooler system, high-performance compressor and power turbine, high-temperature and high-efficiency combustion chamber, The ISO standard output power can reach 40 megawatts, that is, 53,600 horsepower, and the thermal efficiency is 42.2%, which exceeds the thermal efficiency of MT30 by 40%, and slightly exceeds the 42.1% of WR21 in the United Kingdom and 42.1% in the LM6000PC of the United States. The successful development of this type of gas turbine will mark that China has officially become the second country after the United Kingdom to successfully develop and install a 40-megawatt marine gas turbine.
Bai Chunli, president of the Chinese Academy of Sciences, used "the trust of the boat" as a metaphor for Mr. Wu Zhonghua's ability to hold up the great cause of the country and the nation. Our state-of-the-art "Chuanji" gas turbine benefits from Wu Zhonghua's ternary flow theory of impeller machinery more than 70 years ago. The GT25000 series will continue to be the absolute workhorse of the surface fleet gas turbines, ushering in a new era that is even brighter and brighter.