The major costs of thermal power plants and combined heat and power (CHP) plants are from fuels used for generating power, steam and other forms of energies. The energy consumption efficiency, therefore, directly affects costs and competitive advantages as well as greenhouse gas emissions. Meanwhile, the regulations specifying the amount of coal consumption in China have been the challenge, BPP has to adjust itself to cope with such changes. These include improving the energy consumption of existing power plants and developing the future power projects to have lower energy consumption intensity as well as to be part of alleviating the climate change.
Activities involved with energy consumption in generating power, steam and heat include:
- Using coal as a fuel for productions.
- Using diesels to ignite the boilers and as a fuel for heavy equipment and transportations.
- Using gasolines and diesels for transportations.
- Using other fuels for productions such as waste gases from the blast furnace gas industry.
- Purchasing electricity from external sources.
BPP has focused on providing energy management services for the maximum efficiency, namely:
- Selecting the high-performance technology with minimal fuel consumptions and environmentally friendly.
- Improving the boiler efficiency to have the most complete combustion.
- Planning for efficient maintenances to increase the power plants’ availability factor (AF), reducing the planned outage factor and the unplanned outage factor, as well as lessening energy losses from stopping running and starting operating the machine.
- Looking for opportunities to lower heat and power losses in the system and reuse it.
- Improving other supportive systems such as upgrading water quality inside the boiler for longer use, reducing water discharges and filling up new water to the system.
- Seeking opportunities for using more energy sources in the area such as waste gases from the blast furnace gas industry, natural gases, biomass fuels, etc.
- Planning to purchase multiple fuels from various sources in order to manage the fuel supply with high quality and reasonable prices and to reduce any risks associated with fuel shortages.
- Developing the integrated energy management applications for power plants, starting from purchasing, storage, and blending to production’s combustion process.
- Energy consumption intensity of 1.20 GJ/MWh, reducing 22%, when compared to 2020, and 30% better than the target set.
Key Activities and Projects
Since the machinery of Zouping Power Plant has long been used while many of its parts were replaced in order to reduce pollutant emissions or a so called “Ultra–Low Emissions”, it has less efficiency and consumed more electricity. As a result, the power plant’s efficiency has decreased as a whole. In addition, Zouping Power Plant has to generate power and steam of which production procedures are different from its initially operational commencement. The Zouping Power Plant, therefore, developed a plan to improve its efficiency and reduce the power consumption ratio of its machinery so as to increase the power plant efficiency.
The Zouping Power Plant conducted the engineering study and designing the fly-ash transportation system by installing one more bin pump at the ash hopper No. 5 and No. 6. As a result, there are three bin pumps in the system. Moreover, the existing bin pumps installed at the ash hopper No.1, 2, 3 and at the ash hopper No.4, 5, 6 were moved and installed at the bin pump No. 1, 2 and No.3, 4, respectively, so as to make a balance in the system. As a result, the bin pumps were able to reduce their energy consumption to 1,421,400 KWh per annum, equivalent to CNY 640,000 per annum.
Moreover, Zouping Power Plant also installed the rotational speed control equipment of the forced draft fan at the boiler No.4 and No.6 as well as the induced draft fan at the boiler No.6 in order to reduce the rotational speed. Meanwhile, the power plant has been operated at the low operation mode, which can help reduce energy consumption approximately 50% or 9,290,000 KWh per annum, equivalent to CNY 4,200,000 per annum.
As coal with low calorific value (CV) of about 2,000-3,000 kcal/kg is far cheaper and has more volumes than that with higher heating value of 3,400 kcal/kg, currently used in the market, Zhengding CHP Plant conducted a study and an experiment enabling the plant to use lower CV coal in the steam boilers without compromising on safety, production capacity, and stability as well as reducing the power plant’s fuel costs.
The experiment’s key processes included:
- The process of controlling the calorific value and coal quality after blending coal with different heating values from various sources in a coal stockyard.
- Each boiler’s ooperation process, surveillance, and emergency plans preparations.
- The boiler’s maintenance with an emphasis on additional damage inspection possibly caused by corrosion and special protection.
The experiment’s results showed that the power plant’s equipment has the ability to handle coal with the lowest CV of 2,600 kcal/kg. Zhengding CHP Plant, therefore, is currently using blended coal with an average CV of 2,800 kcal/kg, a reduction of about 600 kcal/kg. This has helped the plant to lower its fuel costs to CNY 37.85 million.