The coal-gas transition, a winning strategy in Tianjin, China
Reducing fine particle emissions has been a key factor in the switch from coal to gas at the Junliangcheng Power Plant in Tianjin, China. Other benefits include reduced carbon dioxide emissions, which is important as the world’s most populous nation strives to become carbon neutral before 2060.
Like many countries around the world, China’s mission is to reduce coal-fired power generation. In fact, in 2020, the part of China’s installed power generation capacity that was powered by coal fell below 50% for the first time. It stood at 49.1% at the end of the year, according to the China Electricity Council.
The trend was driven by President Xi Jinping’s desire to see carbon dioxide (CO2) emissions peak before 2030 and decline steadily thereafter. He has set a target for China to be carbon neutral by 2060.
One of the ways the country has moved away from coal is to shift more production to natural gas. While gas production emits CO2, that’s about 44% less than coal on a per MMBtu basis. When you add the higher average efficiency of gas-fired power plants compared to coal-fired power plants, the CO reductions2 emissions are above 59% on average.
Desire to change clean air drives
While President Xi’s carbon neutrality goal is relatively new – he made the announcement in a video chat with the United Nations General Assembly on September 22, 2020 – other emission reduction measures are in place For years. The Tianjin Air Quality Action Plan is one example.
Tianjin is a coastal metropolis in northern China by the Bohai Sea. According to some estimates, it is the fourth largest urban area in China, with nearly 14 million inhabitants. Tianjin has been a major seaport for centuries and is considered the gateway to Beijing, which borders its northwest.
Due to air pollution issues, especially with PM2.5 (inhalable fine particles with diameters typically 2.5 micrometers and smaller), the Tianjin government developed its air quality action plan and released it in 2013. Among the recommended actions was a request for Tianjin Huadian Junliangcheng thermal power plant to make at least a partial transition from coal to gas by 2017 (Figure 1).
1. The Tianjin Air Quality Action Plan has been effective in reducing air pollution in and around the municipality. A clear sky allows the sun to shine brightly on the Junliangcheng power station. Courtesy of GE Power
Gas-fired electricity replaces coal production
The installation of Junliangcheng has a long history. The first 50 MW unit started operating in 1966. By 1971 the plant had been expanded to four 50 MW units. From 1985 to 1993, four additional 200 MW units were added, making the facility Tianjin’s first 1,000 MW power plant. Between 2009 and 2010, the four 50 MW units were replaced by two 350 MW units. The four 200 MW units were closed between 2015 and 2017. Since then, another 350 MW coal unit has been added. More recently, an advanced gas turbine combined cycle unit with a capacity of approximately 661 MW when operating in full condensing mode has been added. (The unit is also capable of functioning as a combined heat and power unit, supplying steam to various customers, which affects power generation to some extent.)
China Huadian Tianjin Junliangcheng Power Generation Co. Ltd., part of China Huadian Corp., is the owner of the facility. It has contracted with GE to supply the gas turbine technology; Harbin Electric was selected to supply the steam turbine, generator and equipment for the rest of the plant. Contracts were signed in March 2017. The owner also subcontracted to facilitate design, construction and commissioning activities.
The gas-fired unit features the first GE 9HA.01 technology commercially exploited in China. In addition to the 9HA.01 gas turbine, GE provided its Mark * VIe distributed control solution, which provides complete control and operation of the combined cycle power plant.
COVID complicates matters
The Junliangcheng gas turbine was shipped from GE’s manufacturing facility in Belfort, France, to the Port of Antwerp, Belgium, in September 2018. It arrived at the Tianjin site in April 2019. The first fire of the unit and its first synchronization with the electrical network took place in September 2020. It began its commercial operation on January 28, 2021. The achievement of such a rapid construction schedule is remarkable because it was carried out despite the obstacles caused by the global pandemic.
“The most difficult aspect was related to COVID-19,” said Yibin Jia, senior project manager at GE Gas Power. POWER. “We couldn’t get enough commissioning resources, so we had to do a lot of remote support work. I think that was the hardest part of the project.
GE had originally planned to mobilize 26 engineers overseas, making them available to participate in local testing. However, when the time came, none of the desired engineers were able to travel due to the pandemic. “On-site support is the norm. In this case, remote assistance required special applications, and overseas engineers looked at the data to monitor performance, and in some cases, troubleshooting took longer, ”Jia said. In the end, the tests were carried out successfully with a single on-site test manager.
The use of remote assistance has not always been an obstacle, however. “Thanks to the tele-support, we completed the commissioning in 10 days. It’s much faster than expected, ”Jia said. “Normally it’s about a month, so we only need a third of the time. In addition, the first fire, entirely carried out by the local team, was completed in three days. The client thought it would take a week.
Training and safety are always a priority
At the height of construction of the Junliangcheng project, which is said to have cost more than one billion RMB ($ 156 million), more than 700 people were working on site. Ensuring that all employees were properly qualified for their jobs and properly trained in safe work practices was a high priority.
“There are actually three types of controls: from the national and local government, from the building itself, and also from the owner’s side,” Jia said. “Local rules require workers to be certified before going to a job site to do construction work – this is the first line. Another line is controlled by the construction company, such as an exam or certification. And another thing is that the owners themselves can also have certification for people who pass the exam before going to the site.
Likewise, the security procedures followed a multidimensional approach. “We had GE’s security procedures. and the client also had their own safety procedure to follow, ”Jia said. “For GE employees, first of all, we have to follow the customer process. Additionally, on the service side, they have their own security procedures, as well as designated security blanket assets to provide security. Thus, we had the safety manager who visited the site regularly to carry out audits. Meanwhile, we have monthly safety management surveys.
In the end, the policies and procedures achieved the goal. “We finished the project without any injuries on the spot,” Jia said.
GE introduced Class H technology to the electrical industry almost 30 years ago. Today, GE’s HA product portfolio, first launched in 2014, utilizes advanced combustion and compressor technology, along with critical advancements in materials science, design and coatings. The company says its cutting-edge technology combines the experience of its proven first-generation H-Class architecture with lessons learned from its advanced aircraft engine technology for award-winning results.
The 9HA.01 installed in Junliangcheng is equipped with several advanced technologies. It features an advanced 14-stage 3D aero compressor for high output and efficiency, as well as electric input guide vane (IGV) actuators to avoid the need for hydraulic oil in the multi-shaft configuration, which leads to simplified gas turbine accessory systems. The latest low NOx (DLN) dry combustion technology, known as the DLN 2.6e combustion system, is also incorporated. It uses an advanced premix, axial fuel staging (AFS), as well as a monocoque liner and transition piece to reduce emissions, improve reduction capability and fuel flexibility. In addition, the unit’s four-stage power turbine provides improved aerodynamics, cooling and sealing capabilities.
As previously reported, GE also provided its Mark * VIe distributed control solution, which helps Junliangcheng improve visibility, reliability and availability of assets, while reducing O&M costs. The Mark VIe is used for programming, configuring, trending and analyzing system-wide diagnostics. The company says it provides a single source of quality, time-consistent data at the controller and plant level to diagnose and adjust plant operation in real time. Getting old POWER The use of remote monitoring and troubleshooting solutions has increased during the global pandemic, and the general trend towards centralized offsite operations has accelerated as a result.
A project to reproduce
GE’s HA gas turbine portfolio is one of the fastest growing fleets in the world with more than 100 units ordered by more than 50 customers in 20 countries. On November 9, 2020, the company announced that it would be involved in an even larger project to convert coal to gas in China. This time, the state-owned Guangdong Energy Group Co. Ltd. has placed an order for three 9HA.02 gas turbines for its Dongguan Ningzhou Combined Cycle Power Plant in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA).
GBA is an agglomeration of cities proposed by China to strengthen international cooperation and promote low-carbon, inclusive, coordinated and sustainable development. The Ningzhou power plant will add 2.4 GW of electricity to Guangdong province in line with national goals of transitioning from coal to natural gas, and it will become one of the largest gas-fired power plants in mainland China. GE will partner again with Harbin Electric to supply the steam turbine, generator and equipment for the rest of the plant for the plant, which is expected to be operational in 2022. ■
–Aaron Larson is the editor-in-chief of POWER.