Powertech Refrigeration’s status as one of Ireland’s premier industrial refrigeration specialists was underlined at the 2022 Institute of Refrigeration Ireland (IRI) Awards, where they were Highly Commended in the Project Innovation category for the successful delivery of a state-of-the-art refrigeration system upgrade at Lakeland Dairies.
Established in County Armagh by managing director David Smyth and business partner Mervyn Hannain in 2004, Powertech Refrigeration provide a dedicated professional service offering specialist industrial refrigeration to businesses across Ireland, the UK and the international market.
Priding themselves on providing high-quality turnkey developments to service various sectors of the refrigeration industry – and specialising in ammonia and chilled water systems – Powertech Refrigeration have successfully delivered solutions within the dairy, meat, fruit & veg ripening, food processing and pharmaceutical sectors amongst others.
Proven market leaders in all types of industrial refrigeration and air conditioning, Powertech have undertaken the design and installation of a wide range of industrial refrigeration projects, using ammonia and pumped liquid C02 refrigerants, throughout Ireland, the UK, Belgium, Germany and China.
Stuart Gwynne was Project Manager for the new refrigeration system at Lakeland Dairies, for which Powertech Refrigeration caught the attention of the judges at this year’s prestigious IRI Awards. As PM, Stuart – who has been part of the Powertech team since the company’s genesis 18 years ago – was involved in every phase of this award-winning project from presentation and design through to installation, commissioning and handover.
“Although it’s not something we specifically set out to achieve, going forward I think it is important for the company to pick up industry awards. Myself and David go back a long way together in the industry as he previously worked for many years for Cross Refrigeration, where I was his junior in the office.
“It’s really encouraging now, after all his investment into Powertech Refrigeration, having started a new business from scratch, that Powertech is being seen as a competent industrial refrigeration company.
“Following on from our success at the Institute of Refrigeration Ireland Awards, I would be keen now to follow up on this and get some more. It’s great for the morale of the team to receive this recognition for their efforts and it’s great for the engineers who are at the coalface to know that they are working on industry-leading projects that are worthy of awards and recognition.”
For the project in question, Powertech Refrigeration were approached by Lakeland Dairies to design and install an ammonia refrigeration system that would utilise existing plant, bringing stability and reliability to this whilst extending the duty of the overall system by adding addition capacity.
The existing system comprised of a pair of ammonia reciprocating Sabroe compressors in line with a common submerged evaporator in an elevated bath with a metered liquid ammonia supply from a pair of Hanson floats having the ammonia condensed with the use of a pair of BAC evaporative condensers sized to each reciprocating compressor.
The chilled water, no glycol and not brine, was then pumped from a gravity fed fixed speed pump set to production and then returned to the open tank again. The system, but especially the open tank (bath) containing the submerged evaporators, was at the point of change over 30 years old.
The initial design from concept put to Powertech was for a traditional pumped ammonia system, utilising a surge drum and liquid receiver with new condenser, to a plate heat exchanger, marrying the existing compressors with new compressors and then chilling a body of water in a new insulated tank, which would be pumped to production from holding and then returned to the tank. While this proposal was acceptable from a refrigeration and engineering perspective, from a risk, commercial, efficiency and environmental standpoint it left great opportunity to value engineer this delivery.
Powertech came up with numerous ways of adding value to the project and these were all agreed to by the client and incorporated into the final design.
From an environmental and safety management perspective, the amount of refrigerant in the system was reduced by changing from a pumped ammonia system to a critically charged ammonia system, while risk was reduced by adding redundance of equipment, changing from a large plate heat exchanger and utilising alternative heat exchange equipment (in this case, the Vahterus shell and plate exchanger).
The opportunity was seized to use a de-super heater arrangement on the common ammonia discharge to preheat water going to the boilers of another system within the facility, adding efficiency to the refrigeration system by not needing to run the condenser at peak load but also using less fossil fuel at the boiler to create the same amount of heat required for its production needs.
The client was encouraged to consider and allow the upcycling of a pre-existing tank to be utilised for water storage for the project. Again this lowered the environmental impact as the embedded carbon of new stainless steel and insulation was eliminated. Funds saved were re-assigned to optimise other parts of the project.
A smart variable speed pump set from KBS was used to optimise the pumped water efficiency as well as cycling the lead and follower pumps to add longevity and control to the physical pumps and system, allowing high tolerances of control to be implemented directly to the water chilling process without freezing up of the ammonia/water exchanging system.
Siemens control of the entire system was implemented with in-house logic and programming to monitor and control the delivery of the chilled water to the working environment. This was favourable to the customer as it aligned with the ICT standardisation of their business.
The availability of space on site was at a premium and the ability to use an air (adiabatic) cooled condenser could not be accommodated. The next best option was to use a common evaporative condenser for the Total Heat Reject and oil cooling of the compressors, this coupled with floating head pressure control left for a robust tried and tested solution.
Optimising on-site installation time and minimising disturbance to the customer, most of the pipework and bracketry was formed off site and then delivered to site for installation.
After these – and other – design changes had been agreed and implemented into the design, the final part of the process was to coordinate and deliver the project. This was achieved by Powertech’s highly-skilled and dedicated delivery specialists, from design and project management, upholding best practises of EN378 in relation to refrigeration but also Health and Safety, as well as best practises of international project management ANSI/PMI 99-001 through to commissioning and maintenance teams, combining their knowledge and skill of each component of the system as well as their knowledge of integration into a highly efficient system which had low electrical consumption with high refrigeration yield coupled with close control and reliability for the end user for now and for years to come.
The system ran flawlessly with water delivered at desired temperature and little to no variation or risk of freeze up due to the system control and noted by customer a decrease in power consumption, but a higher more reliable production yield was attached. The customer’s interaction with the system was simplified and streamlined from control (Production) and monitoring (BMS) perspective; also observed was a time decrease in system start up, and the close pressure control given by the inverter driven water supply pumps regardless of demand.
The customer has reported a dramatic reduction in site attendance by refrigeration engineers at peak times of the year to safeguard production, concluding that the proposed design did deliver and de-risk production with the delivery cost and time being confirmed and held from the moment of concept to final handover and beyond.
“The company has grown from humble beginnings 18 years ago to establish ourselves as a leading industrial and commercial refrigeration specialist,” Stuart continues. “There is still room to grow the business further. We currently have a close-knit and elite team of eight engineers and six office-based personnel, the majority of whom are technically-orientated.
“We’re lucky to have a very strong team. Our engineers are knowledgeable and they have bought into David’s vision for the company and they are all pulling in the same direction.”
Regarding the Lakeland Dairies project, the award-winning PM adds: “It was a pre-Covid job and a time-sensitive one as it had to be up and running again quickly before the milk came back on line. As part of the work, we also had to take away the old existing system, which was 45 years old; dismantling that and disposing of it safely was a challenge in itself.
“Their pre-existing system was very old and inefficient and they needed more refrigeration capacity for the future and they were keen for us to find as many efficiencies as possible, which we did right across every aspect of the upgrade. We’ve actually been back on that site since and upgraded the system with a new condenser, adding even greater efficiency.”
As an independent company, Powertech Refrigeration source and distribute equipment tailored to the client’s needs and specification. They are distributors in Ireland for Aermec air conditioning systems and water chillers, who have been leading market providers in the air conditioning industry for over 50 years.
From start to finish, Powertech Refrigeration’s highly qualified and experienced engineers – who are fully trained and certified to work on ammonia, HCFC, HFC and CO2 refrigeration systems – ensure that every project is delivered on time, to specification, within budget and with a complete technical handover and supporting documentation.
At the time of writing, Powertech had just finished a large 110m x 20m x 10m high chilled water system for Musgraves in Blanchardstown, with a twelve-metre modular section of pipework which significantly reduced installation time spent on site.
“As well as refrigeration, we’re moving more into process and process control, which is an area where we have identified great opportunities,” Stuart concludes. “Key to that is the emphasis on saving energy and the requirement that a system only uses the energy it needs. That’s going to be a big thing going forward with chilled water, especially with the price of electricity.
“We have to keep a very close eye on tapping into any efficiencies we can find for our customers. You measure this across the lifetime of a system, so you are not just thinking about the cost of installation but also how much the system is going to cost in the long term.”
Powertech Refrigeration Ltd.,
94A Gosford Road,
Markethill,
County Armagh.
Tel: +44 28 3755 2792
Email: [email protected]
Web: powertechrefrigeration.com
This article was published in Building Ireland Magazine, January 2023, Vol 9 No 1
