A FANTASTIC ENERGY SAVINGS SOLUTION FROM GRUNDFOS

Pumps & Valves

Great changes observed from a site survey – a tech focus on how the Grundfos pump technology can help to save on energy costs
By Le Thanh Hai, Regional Sales Manager, Mekong Delta, Grundfos Vietnam

Do you know that your water supply system can hold significant unrealised energy savings potential? Worn or incorrectly sized pumps typically lead to energy wastage, as was the case demonstrated at the Ca Mau municipal water supply company.

When the Grundfos team visited Ca Mau’s existing ground water pumping station at the Mekong Delta in May 2015 to understand how the pumps work, a surprise was waiting for them – there was an abnormal vibration on the discharge pipe although it was only producing 45m3/h. One possible cause of this was the motor size.

A quick survey was done by the Grundfos team, which calculated the flow gained from flow meter, dynamic water level and discharge pressure. Using the formula below confirmed that the motor size was too big for a 30kW pump, and this contributed to energy wastage:

 

The operator further added that the cast iron pump was rewound many times, and most of the existing pumps in the company are of similar sizes. Due to a lack of pump knowledge, it was difficult for operators to evaluate the pump performance in each well.

Grundfos held a meeting with the company’s technical department to understand the existing situation and a decision was made to conduct an energy check for all 53 wells to evaluate the current energy consumption to produce one cubic metre of water. Two weeks after both parties agreed on the proposed methodology and tools to ensure all parameters are measured correctly, Grundfos gave a pump knowledge seminar to over 60 participants covering the basic elements of a ground water pumping system, energy consumption calculations and the energy check tools and methodology.

The results showed that with a production capacity of 53,000m3/day, the total power consumption of all pumping stations was 17,490kw per day and the energy required was 0.33kw/m3 - a very big number. Upon Grundfos’ analysis, they discovered that the company could effectively reduce its energy consumption to 0.21kw/m3 by replacing the current equipment with appropriate pumps and modifying the pumping stations.

A month after installing two Grundfos pumps (SP46 and SP60), results yielded confirmed energy reductions that met the company’s expectations.  A comparison with other brands convinced the customer that Grundfos’ SP pumps are good products with highly efficient performances and long lifespans, thanks to the pumps’ full stainless steel material, new MS6000 version C motors, MP204 control boxes, and expandability on remote monitoring. More importantly, the good reviews reflected by many municipal water supply companies in Mekong Delta that have been long-term users of SP pumps influenced the customer’s decision to switch to Grundfos.

“Due to the size of the investment, the company is considering doing it in multiple phases, funded by the company and money saved from energy savings. This improvement is vital for the company. When completed, Grundfos SP pumps can reduce our energy consumption by 6,000kw/day, which is equivalent to 3.800.000.000VND/year. Although the investment is huge, payback is estimated between two and three years, and Ca Mau municipal water supply company strongly believes that the savings from switching to Grundfos will pave a better future for the company,” said Mr Ly Hoang Trung, Director of Ca Mau municipal water supply company.