Energy-efficient pumps in action
Modern pumps are highly efficient, reliable and controllable — as demonstrated by a major project described by Gary Wheatley of Wilo UK.
Pumps play an essential role in keeping buildings working and are broadly responsible for around 20% of all the energy consumed on the planet. All buildings have pumps operating as part of the heartbeat of their operation — providing heating, cooling, air conditioning and moving sewage and greywater. They are at the heart of the majority of processes in our factories and manufacturing plants, play a vital role in our public buildings and ensure that the wider sanitation systems in the country and, indeed, the world, continue to operate efficiently.
The advent of high-efficiency pumps and pumping systems is of course a huge step forward — partly driven by legislation and partly driven by common sense and a desire to use less energy, pay lower energy bills and, to a degree, reduce carbon emissions. To assess the benefits of new pump technology, it’s useful to look at a major new-build project where new pumps have been specified and installed across a wide range of areas and integrated with the building-management system to maximise on the benefits these high efficiency pumps can offer a building owner.
Palm Papers a German company with seven paper mills across Europe has recently built a new plant in Kings Lynn. An impressive new base for its work in the UK and Ireland, it’s one of the world’s largest and most efficient newsprint paper mills producing 400 000 t of newsprint a year with a working width of 10.63 m, producing around 2000 metres of paper per minute.
The production of paper from recycled paper is an established and energy- and cost-efficient method of producing paper and saves hugely on the use of virgin wood from managed sources. Not only are forests conserved, but making paper from recycled paper saves around half the energy and one third of the water needed for paper from wood pulp. In addition the effluent and waste produced is far lower.
The new building sits on a 50 acre site in north Norfolk. It represents a huge investment in environmentally friendly technologies and it’s a building that sets new standards when it comes to environmental performance.
The total pump infrastructure in the building has been supplied by Wilo in a project valued to the company at around €400 000 and covering heating, cooling, water supply and sanitation.
A paper mill is responsible for a serious amount of wastewater, so a dedicated private sewage facility was built as part of the project. From this, about 96% of the wastewater can be recycled, meaning very little water needs to be sourced from the nearby River Ouse, and the water that is put back into the river is actually cleaner than the water taken from the river originally.
Wastewater from the plant is dealt with by five EMU FA08 submersible pumps and two EMU FA10 pumps. These are specially designed to pump waste water containing solids and for sewage plants and pumping stations for water management and industrial applications.
EMU FA submersible pumps are also used for rainwater collection and drainage on the site — a total of 12 pumps comprising EMU FA20 and 30 models. each pumping up to 900 m3/h. Four relays control three pumps each and are connected by the Modbus protocol to the building-automation system.
In the building, the air-conditioning and process cooling use Wilo pumps as well. The 2.3 MW cooling requirements are dealt with by two quantum refrigeration compressors. Veroline IPL and IPE inline pumps are utilised for chilled-water distribution. In the laboratories cold-water distribution is controlled by two Stratos CAN pumps, integrated via an IF module linked to the building-automation system. These pumps are based on electronically commutated motors, which offer double the efficiency of an electronically controlled pump with a conventional drive. Stratos high efficiency pumps have been optimised to the operating conditions of the air-conditioning refrigeration area. They are capable of operating happily under a wide range of liquid temperatures. from -10 to +110°C and are protected by a cataphoretic coating to guard against corrosion.
Only the most energy-efficient pumps were considered for the project with Stratos and Stratos ECO installed. The heating system comprises five sub-divisions — a total of 13 circuits which are also controlled by the building automation system.
To provide the required levels of water pressure around the buildings, Comfort-Vario pumps are installed, with four pumps providing a flow of 25 m3/h at a head of 80 m. Once again, this system is monitored and controlled by the building-automation system.
This integrated pumping system illustrates the energy efficiency benefits of utilising high efficiency pumps, delivering significant operational benefits and savings — not only in lower energy bills but also in the lower maintenance costs because of the high reliability of these pumps and in-built protection to ensure they run with minimal interference and maintenance.
The lower life cycle costs associated with selecting such pumps is a vital benefit to any major organisation looking to incorporate this number of pumps in an integrated system that needs to operate constantly with the minimum of fuss.
Gary Wheatley is technical manager with Wilo UK.