HIMOINSA has undertaken a major project to improve the environmental conditions of a key infrastructure in Vietnam: the construction of the Nhieu Loc Thi Nghe wastewater treatment plant (WWTP). The treatment plant is part of a strategic alliance between Acciona and Vinci and is located in Ho Chi Minh City, which has a metropolitan area of 14 million inhabitants and is the most populous city in Vietnam.
Ho Chi Minh City is sixty kilometres from the sea and is currently the country's main industrial and economic centre. HIMOINSA has contributed its expertise to this strategic project by developing a reliable and efficient energy system adapted to the complexities of the environment to ensure the continuous operation of the wastewater treatment plant.
Vietnam is located in Southeast Asia and has a tropical climate. With average temperatures of 28 degrees Celsius and humidity levels of around 75 per cent, the country has an abundance of water resources. However, due to its climatic and geographical conditions, water is unevenly distributed and supply difficulties are common. As a result, infrastructure modernisation has become one of the objectives of its water management policy in recent years. HIMOINSA has designed a solution based on the country's specific environmental conditions and climatic and environmental requirements.
The project has addressed a series of specific technical requirements to ensure critical power supply in the event of an outage on the main grid. This has involved installing medium-voltage (6.6 kV) and low-voltage (380 V) diesel generator sets to ensure a reliable and continuous response capacity adapted to the system's load conditions.
The scope of the installation has included both the supply and installation of seven generator sets: five 6.6 kV, 2000 kVA medium-voltage emergency diesel generator sets, one 380 V, 1600 kVA low-voltage generator set, and one 380 V, 1250 kVA generator set. The gensets had to be designed to meet electricity demand in emergency situations, and to optimise performance by minimising losses.
They have been configured to provide a continuous rated power (PRP), taking into account key factors such as distribution line losses, engine start-up, and the required start-up method in each case. They also had to be able to withstand overloads of 10% for one hour in every 12-hour period, without compromising the thermal integrity of the equipment insulation. All calculations and designs were carried out on the basis of a power factor of 0.8, in line with international standards for emergency applications in critical installations.
One of HIMOINSA's many strengths lies in its ability to provide customised acoustic engineering solutions. We were therefore able to implement a stringent noise control system to minimise the acoustic impact on the area around the sewage treatment plant, thereby meeting both the project's regulatory and environmental requirements and the client's expectations. Each generator set has been encapsulated in a specially prepared ISO 40FT-HC sea containers to ensure a maximum sound pressure level of 75 dB(A) at 1 metre.
With projects such as the Nhieu Loc Thi Nghe wastewater treatment plant (WWTP), HIMOINSA reaffirms its exceptional ability to design bespoke systems and solutions for each client. On this occasion, it has provided a robust power solution capable of ensuring emergency supply in critical conditions. The models chosen for this project guarantee stable operation in situations of high demand.
In total, we have installed five HTW-2080 T5 (6.6 kV) units for medium voltage, one HTW-1745 T5 (380/220 V) unit, and one HTW-1260 T5 (380/220 V) unit. They have all been designed to ensure optimal integration into the project's electric system as a whole, with particular attention being paid to load control.
