Recently, a certain gas turbine engine’s exhaust system testing was completed three days ahead of schedule, smoothly accomplishing all test objectives and passing the on-site review. In the reports, there were frequent mentions of “engine installation on ships,” “system onboarding,” and “test sailing,” clearly indicating that this successfully tested “gas turbine engine exhaust system” is intended for new types of ships.
What is a Gas Turbine Engine?
A gas turbine engine is a type of rotating thermal engine that uses air and gas as working fluids. Its structure is similar to jet engines used in aircraft and also resembles steam turbines. The main components include the gas turbine (turbine or power turbine), compressor (air compressor), and combustion chamber. Its working principle involves the compressor drawing in air from the outside, compressing it, and sending it into the combustion chamber. At the same time, fuel (gas or liquid fuel) is injected into the combustion chamber and mixed with the high-temperature compressed air for combustion. The generated high-temperature, high-pressure exhaust gas enters the gas turbine for expansion work, driving the power blades to rotate at high speed, and then the exhaust gas is discharged into the atmosphere or further utilized.
Therefore, to meet the quality requirements of combustion and cooling air for shipboard gas turbines and to ensure the reliable operation of ship power systems, exhaust gas systems are indispensable equipment in shipbuilding technology. The completion of exhaust gas system testing also signifies that shipboard gas turbines can now be mass-produced.
Combining the reports in the article, we can see that this shipborne engine is the Chinese new generation CGT-40 gas turbine engine. The related data and performance of which have already been disclosed by the country, surpassing Rolls-Royce’s most advanced MT30 shipborne gas turbine engine and becoming the world’s most powerful shipborne gas turbine.
China Leads the World in Gas Turbine Engines
China, the United States, and the United Kingdom are the only three countries globally capable of mass-producing shipborne gas turbine engines. Initially, the Soviet Union was also capable. The Soviet Union’s gas turbine technology was so advanced that it was the first country in the world to adopt an all-gas turbine power unit.
Leaving aside other aspects, let’s talk about the GE9 core technology developed by the former Soviet Union, which was later utilized by General Electric Company and France’s Snecma. Their CFM56 high bypass ratio turbofan engine was developed based on the GE9.
However, unfortunately, after the dissolution of the Soviet Union, neither Ukraine nor Russia inherited the complete set of shipborne gas turbine technology.
Britain, on the other hand, is the strongest in shipborne gas turbines and has the longest history of gas turbine development. The power of the MT30 gas turbine engine reaches 36 megawatts (approximately 50,000 horsepower), with a maximum power of 40MW, undoubtedly making it the most powerful marine gas turbine engine in the world currently.
With two MT30s plus four diesel engines, the 65,000-ton “Queen” class aircraft carrier can reach a speed of 27 knots at sea! The propulsion power of two MT30s can easily serve as the sprinting main engine for tens of thousands of tons of destroyers, and even the US Zumwalt class employs the MT30.
However, this gas turbine engine has some reliability issues, especially targeting the United States. The first three ships of the U.S. Navy’s Freedom-class littoral combat ships all experienced MT30 engine failure problems to varying degrees.
The Zumwalt experienced an MT30 failure during its transit of the Panama Canal in 2016, resulting in the entire ship losing power. It had to be towed back to the shipyard. The Michael Monsoor (Zumwalt-class second ship) experienced a severe MT30 turbine failure during sea trials in 2017, delaying its commissioning by a year.
However, China’s CGT-40 gas turbine engine is even more powerful, with a rated power of a terrifying 42 megawatts, equivalent to 57,000 horsepower. Furthermore, its thermal efficiency reaches 39.5%. Not only that, but China’s gas turbine engines have undergone multiple tests, significantly improving their reliability.
With such immense power, who will be the first to adopt it?
Who Will Be the First to Adopt?
There are two possibilities here: Firstly, this successfully upgraded shipborne gas turbine engine is prepared for the follow-up improvements of the People’s Liberation Army’s active ships, such as the speculated 055B-type 10,000-ton destroyer. The GT-25000 gas turbine engine is the power system of the Chinese 0555-type missile destroyer, with a rated power of only 25 megawatts and a thermal efficiency of 36.5%, with an exhaust temperature of 480℃.
The 055 destroyer must be equipped with four CGT-25M gas turbine engines. With four engines, it becomes the fastest missile destroyer; however, two engines are too weak, and the large size of CGT-25M results in the first batch of 055 destroyers having a relatively large power system space.
After adopting two CGT-40s, the 055B will have more space, providing the possibility for the ship to be equipped with an all-electric propulsion system. Moreover, with the coordination of a medium-voltage direct current comprehensive power system, the ship’s power will already have reached a saturated state, allowing the 055B to accommodate high-energy weapons or additional vertical launch missile systems.
Secondly, this shipborne gas turbine engine may be intended for a yet-to-be-announced new type of ship, with the possibility that the new ship may be the long-rumored 076 ship.
076 Ship Requires Powerful Propulsion
Although the 075 ship belongs to the amphibious assault ship category, the positioning of the 076 ship is not limited to that of an amphibious assault ship. Many believe that it is the “versatile warship” proposed by academician Ma Weiming, which is a novel ship type pioneered by China, while foreign countries believe it could be an unmanned aircraft carrier.
What can be confirmed is that the 076 adopts a flat deck, which is characteristic of an unmanned aircraft carrier, allowing unmanned aircraft to take off and land freely on the flat deck. However, the 076 also features a dock and electromagnetic catapults, giving it the ability to launch fixed-wing carrier-based unmanned aerial vehicles and manned aircraft. Its functionality is expected to extend beyond that of just an unmanned aircraft carrier.
Moreover, compared to the domestically-built electromagnetic catapult aircraft carrier “Fujian,” which has a displacement of over 80,000 tons, the 076 type ship is significantly smaller. If “Fujian” has already reached the threshold of a “super carrier” in terms of tonnage, then the 076 type ship belongs to the category of “quasi-large aircraft carrier.” It may be slightly smaller than the “Liaoning” and “Shandong,” both with a displacement of over 60,000 tons, but larger than mid-sized carriers like India’s “Vikrant,” with a displacement of around 40,000 tons.
The 076 seems more of a technical validation for a versatile ship. It can be used as an unmanned aircraft carrier, carry aircraft, transport tanks, landing troops, and also be equipped with high-energy weapons. This will be a novel ship type pioneered by China.
For this, it naturally requires a powerful heart. The CGT-25M gas turbine engine’s power is insufficient. Therefore, the CGT-40 gas turbine engine can provide the 076 with faster speed and greater endurance.
Regardless of which type of warship adopts the CGT-40 gas turbine engine, it can be foreseen that with the world’s strongest power, Chinese warships will surely dominate the four oceans.