Application of small industrial steam turbine generator sets in self-provided power stations

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Make full use of energy at various levels, and generate electricity and provide heat by utilizing waste heat and pressure. The steam pressure in heating boilers is generally above 0.8 MPa, with temperatures reaching over 270°C. In contrast, the production equipment in industries such as papermaking, printing and dyeing, chemicals, brewing, and sugar production uses low-pressure or pressure-free vessels. To protect this equipment and meet the requirements regarding steam parameters for the production process, temperature and pressure reducers must be installed; as a result, the available thermal energy is wasted. Utilizing the steam pressure difference to drive steam turbine generators to produce electricity represents the best way to save energy and increase efficiency. Turbogenerator sets generate electricity by utilizing the temperature and pressure differences of steam between a boiler and a heat network, offering high efficiency in the comprehensive use of thermal energy and low electricity generation costs. Calculated at 400 RMB per ton of standard coal with a calorific value of 5,000 kcal/kg, the cost of power generation is 0.15–0.25 RMB per kilowatt-hour, whereas the current price for purchasing electricity is around 0.5–0.7 RMB per kilowatt-hour. A 1,000-kilowatt back-pressure steam turbine generator, with an annual generation capacity calculated based on 6,500 hours of operation (out of 8,760 hours per year), can generate 6.5 million kWh of electricity. With a profit of 0.3 yuan per kilowatt-hour, the annual profit can reach 1.95 million yuan. The investment in a 1,000-kilowatt back-pressure steam turbine generator is only around 1.2 million yuan, and the entire investment can be recovered within seven to eight months. The steam turbine generator set features a single-layer, quick-install structure, which significantly saves users’ investment in the foundation and design costs for the plant. Example: A printing and dyeing factory in a certain city originally had a 20-ton steam boiler with a rated steam output pressure of 25 kilograms. However, only 5 kilograms of steam were needed for actual production purposes. Before the installation of steam turbine generators, the boiler operated at a reduced pressure, with its steam output pressure adjusted to 5–8 kilograms to meet the steam requirements for production. However, with the adoption of steam turbine generators, the backpressure steam is discharged for use in production. This allows the company’s existing boilers to generate electricity by taking advantage of the temperature and pressure differences between the boilers and the heat network, while still ensuring an adequate supply of steam for production. This approach yields dual benefits in terms of steam and electricity, enabling a significant reduction in the company’s production costs and energy consumption. At the same time, it creates substantial social and economic benefits for both society and the enterprise. (Photo 001—Application of small back-pressure steam turbine generators in textile dyeing enterprises) 2. Power generation using by-product steam: A phthalic anhydride plant uses the by-product steam from its reaction tanks to drive three 1500 KW steam turbine generators; the entire investment can be recovered within half a year of operation, with an annual net profit of over 8 million yuan per generator. Before the renovation, the by-product steam was released into the air, causing a mist to envelop the area for miles around all year round. Noise pollution and steam pollution were common sources of complaints from local residents. After the renovation, the sky became clearer and the noise levels met the required standards. The condensate water is now recycled for use, and the large water treatment plant is essentially idle nowadays, which saves on water treatment costs as well as valuable groundwater resources. A truly sustainable circular economy model that transforms waste into assets and harm into benefits has been achieved.