Case study: Hanoi Beer Joint Stock Company – Hai Duong
Case study: Optimization of boiler operation and wall insulation improvement to reduce energy consumption at Hanoi Beer Joint Stock Company – Hai Duong
Formerly from a noodle processing enterprise that was constructed with the support of Soviet Union (formerly), Hanoi Hai Duong Beer Joint Stock Company (the Company) has undergone many times of renaming and converting production and business.
In 1991, the Company started producing beer and soft drinks. By 2003, implementing the policy of enterprises equitization, the Company was converted from a state-owned enterprise into a joint stock company.
The company currently has a modern and advanced production equipment systems that were manufactured by Vietnam and Germany such as: Kiesselguhr and PVPP Filter system with capacity of 150 hl/hour; Bottle extraction system with capacity of 15,000 bottles/hour that was manufactured by KRONES. AG Group from Germany; cooking system, Fermentation with PLC control made by POLYCO – VN … with a capacity of 50 million liters of all types of beer annually.
The primary goal and being a key to ensure the success and development of the Company is the food hygiene and safety as well as product’s quality assurance. Through the application of quality management system according to ISO 9001:2008, the food safety and hygiene management system – HACCP ISO 22000: 2005, environmental management system – ISO 14001:2005, the Company is committed to satisfying all consumers’ needs with the quality of beer products supplied to the market such as Hai Duong Beer and Hanoi Beer – a product produced with the cooperation of HABECO.
Image of the Company’s main products
Besides, the Company is also very interested in solutions to reduce production costs and protect the environment such as saving energy. In the past time, the Company has cooperated with national experts of the Project “Promotion of Energy Efficient Industrial Boiler Adoption and Operating Practices in Vietnam” (Boiler Efficient Project) of Ministry of Industry and Trade (MOIT) and the United Nations Industrial Development Organization (UNIDO) to carry out the assessment of boiler efficiency as well as to provide consultancy on implementation of solutions to improve boiler efficiency for saving energy consumption.
The Company’s steam system is defined as a key energy user of the Company. Fuel costs for steam systems account for nearly 45.1% of total energy costs.
The company’s steam supply system consists of 02 4B coal-fired chain grate boilers, each has a capacity of 4 tons of steam/hour. Boilers run alternately, providing steam for the production process. The boiler operates at a pressure of 5 bar.
Image of boiler of the Company
Steam is used for the heating process for hops boiling pots, accounting for nearly 80% of the boiler steam output. Also steam is supplied to the bottle filling line. Demand for steam at the filling line accounts for about 20% of the total steam production of the Company.
Steam system diagram
Evaluation of boiler efficiency done by the UNIDO Project’s Experts
Under the framework of the Efficient Boiler Project, two national experts were sent to the Plant to carry out the efficiency evaluation of a boiler operating on 9 March 2018 with the support of a senior technical expert of UNIDO. The findings from this evaluation are as follows:
- Operating efficiency of the boiler is still low (62.7%) due to the boiler does not have any waste heat recovery devices for energy savings such as economizer and air preheater;
- Average stack temperature is very high, at about 270-280oC (allowed level is 150-160oC) causing great heat loss;
- The average oxygen content in the stack is high, about 11%;
- The feed-water has good quality (155.7 µs/cm), however, the boiler blowdown flow is very high and unreasonable, resulting in a large amount of heat loss through the blowdown process. The conductivity of the blowdown water is 1789 µs/cm, which is too low compared to the boiler water standard of about 5000 µs/cm.
- The shell insulation layer is not in good condition, resulting in heat loss through the boiler shell;
- The flow path of stack in furnace is short which leads to the poor heat exchange efficiency, high stack temperature;
- Heat loss through the ash is too high (6%) due to the incomplete combustion.
Based on the collected data and the above findings, some energy saving solutions are proposed as follows:
- Install the economizer and air preheater to recover the stack heat;
- Perform a proper blowdown process in combination with an automatic boiler blowdown controller.
- Improve the furnace wall, extending the flow path of stack in order to increase the heat exchange efficiency;
- Adjust the boiler operating procedures to optimize the combustion, bottom blowdown processes…
After carefully reviewing the energy saving opportunities that were recommended by the national expert team, the factory has implemented the following solution:
- Application of the standardized boiler operating procedures that were developed by national experts such as blowdown process, adjusting combustion process, controlling fuel input well. These solutions are only to change the operating practices and control methods, no cost required for the implementation but they has brought the coal saving of 100 tons/year, equivalent to the saving cost of 411 million VND/year.
Renovation of the furnace wall to increase the efficiency of heat exchange with a longer stack flow path/line. The implementation of this solution has brought about 59 tons of coal savings per year, equivalent to 242 million VND/year; With the implementation investment cost of this solution is about 380 million VND, the payback period of the solution implementation is 19 months.
Image of completion of wall improvement
Summarizing the results of implementing solutions on adjustment of boiler operational procedures and renovation of furnace walls, they resulted to improve the boiler efficiency of the company from 62.7% to 76.2%. In addition, the implementation of boiler efficiency improvement solutions also helps to improve the working environment of operators who are working directly in the boiler workshop.
Project Management Unit.