Heat pumps: transforming the world’s energy landscape

Heat pump technology is becoming more widely used around the world in numerous sectors to capture, boost and reuse what would otherwise be waste heat. This upcycling can significantly bring down heating costs and reduce reliance on fossil fuels. When applied at scale, considerable financial and ecological advantages can be achieved.

In recent years, GEA has installed ammonia-based heating and refrigeration technology in food processing plants, beverage and dairy facilities, breweries, cold stores, district heating schemes and other establishments.

Why ammonia?

Ammonia’s thermodynamic efficiency makes it a very economical choice, and, thanks to improvements in compressor technology, ammonia heat pumps can now produce higher temperatures than was previously possible.

In a large facility where both heating and cooling are required, such as a district energy network or food factory, ammonia heat pump technology can provide 40% lower energy consumption, up to 40% lower cost and 40% fewer emissions than the use of synthetic refrigerants.

Heat recovery for warming and cooling

Wanting to expand the reach of environmentally friendly heating and cooling, a leading Canadian refrigeration and heating supplier embarked on an ambitious project using GEA technology to supply 557.000 square meters (six million square feet) of building space with district heating and cooling.

In order to meet these extensive requirements, GEA custom engineered and delivered two GEA RedGenium heat pumps to the site in Ontario, with each heat pump providing 2 megawatts (569 tons of refrigeration) of hot water at 85°C (185°F), as well as 4.4°C (40°F) cold water for chilling requirements.

Whereas traditional synthetic refrigerants like hydrofluorocarbons (HFCs) are known to be damaging to the environment, the new system makes use of the natural refrigerant ammonia. It has an ozone depletion potential of zero.

Sustainable efficiency

At the heart of each of the RedGenium heat pumps is an extra-high-pressure GEA V XHP reciprocating compressor. With the ability to provide water temperatures up to 95°C (203°F) and a large capacity range with a maximum design pressure of 63 bar (914 psi), the ammonia-based system provides best-in-class performance. This results in lower total cost of ownership thanks to its significantly low power consumption and ammonia being relatively inexpensive to source.

The system then uses a small input of (ideally renewable) electricity to boost the captured heat. Variable frequency drives run the electric motors, and high-efficiency plate-and-shell heat exchangers allow the entire system to meets the highest standards of sustainability.

Heat pumps reducing emissions at Mars

Leading confectionery manufacturer Mars has installed a GEA ammonia heat pump solution at its facility in Veghel, Netherlands, one of the largest chocolate factories in the world. After analyzing energy-saving and energy-management opportunities at the facility, it was decided that installing heat pump systems would significantly enhance the energy efficiency of Mars’ overall operations and support the company’s commitment to reducing emissions.

The customized GEA heat pump solution, which is based on the GEA V HP reciprocating compressor, extracts and boosts what would otherwise be unusable low-temperature heat from the refrigeration units, which is then used to heat water. Heat taken from the refrigeration units is passed through a heat exchanger, which can heat water up to 63°C (145°F).

This water is then channeled through the factory’s specially installed rooftop warm-water piping network, from where it can be sent to various areas for use within the plant, including chocolate and syrup storage and air-handling units. The amount of heat saved by the heat pumps is the equivalent of about 26 terajoules in gas and approximately 1,000 tons of CO2 emissions per year.

Mars plans to install more heat pumps at other facilities around the globe, as waste heat re-use is one of the key enablers for the company’s target of becoming energy neutral by 2040. 

Revolutionizing juice production

As part of a vast endeavor to build a completely carbon-neutral juice factory, smoothie and juice brand innocent entrusted GEA with providing sustainable processing, heating and refrigeration technology for its new site. GEA’s early involvement in the project meant that numerous innovative processes could be put in place from the outset, positioning innocent well on the way to achieving its sustainability goals.

At the heart of the energy-saving setup at innocent are GEA heat pumps. Integrating systems together for maximum efficiency, GEA advised innocent to use two separate heating circuits – one set to 65°C (149°F) for cleaning and the other to 90°C (194°F) for pasteurization and sterilization. Heat pumps were incorporated to heat water from the waste heat generated in the processes. GEA had to minimize the amount of steam to such an extent that a green energy-fed electric steam generator could be used. 

“Traditionally, all heat is provided above 100°C (212°F) using steam as a medium in beverage production,” says Robert Unsworth, Global Technical Sustainability Manager at GEA. “But we called that into question. Now only a fraction of the heat is requiring steam, which is used for sterilization.” By exploiting the heat exchanger principle to maximum effect, incredible gains were made in terms of heat reuse, vastly reducing the huge amount of energy previously wasted on unused steam.

The project went on to win gold in the European Heat Pump Association (EHPA) People’s Choice Award. “I take my hat off to GEA because they have been at our side every step of the way, helping us challenge conventional design approaches,” says Andy Joynson, former director of operations for innocent drinks Europe. “All the little details add up to a great success. We’re operating with something like 60% of the energy demand that would be required to run a plant of equivalent size, so it’s a significant difference.”

Combined solutions at Wipasz chicken factory

A large and complex solution was required at Wipasz SA, one of the largest Polish feed producers and a leader in the production of fresh chicken meat. For its new poultry plant, at Międzyrzec Podlaski in Poland, the company was seeking solutions to make production more sustainable and energy efficient.

Andrzej Wachink, Technical Director of Wipasz S.A., said, “The new plant is very vast and very modern. We set GEA three challenges: keeping the plant cool; recovering waste heat to reduce energy consumption of boilers used to produce hot water, and creating adequate ventilation, especially in the slaughter area.”

The freezing and chilling processes are extremely temperature sensitive, with product for fresh distribution packed at 0°C (32°F) and the remainder batch frozen to -18°C (0°F), for export or further processing, such as for chicken nuggets. 

To meet the plant’s varied requirements, GEA designed, engineered and delivered 5,3 megawatts (1,507 tons of refrigeration) of cooling capacity for five plate freezers, five batch freezing tunnels, two cold stores, and 64 air coolers. The equipment includes GEA reciprocating compressor units – a Grasso reciprocating compressor V1800 for air conditioning of the plant, a Grasso screw compressor SP1 driving the main cooling process for poultry, and a Grasso screw compressor SP2 for freezing and generating the heat for water and air conditioning. 

In addition, the firm has installed eight air handling units for ventilation of the production rooms and four for air conditioning of the office building, all supplied with cooling from the central ammonia plant and heat recovered from it. Wipasz was also equipped with two heat recovery systems that cover the facility’s entire hot water needs and other heating demands, including offices and social areas, meaning a reduced carbon footprint and very quick return on investment thanks to the lack of boiler requirement.

When a heat pump is combined with a refrigeration unit, both cooling and heating are possible, turning one-time use into a continuous cycle and lowering energy costs by 40% or more. That’s a significant saving when you consider that within the food, dairy and beverage industries, up to 60% of energy usage goes to heating and cooling. Poultry factories such as Wipasz see the significant financial and environmental benefits of using heat recovery and a heat pump in production processes, especially those that require the application of heat during preparation and subsequent chilling and freezing.

Futureproof heating and cooling

The heat pumps installed by GEA at facilities around the world are custom engineered to meet precise temperature requirements and will remain future proof for many years to come, thanks to the long lifespan of ammonia. Compared with other refrigerants, which may last just 10 years or so, outlay on an ammonia system is safe for 30 to 40 years, possibly more.

As fluorinated gases are phased out worldwide to reduce greenhouse gas emissions, natural refrigerants like ammonia are increasingly being adopted. This has paved the way for their wider use and, as demand for green energy solutions expands, ammonia heat pumps are now becoming more widespread in thermal energy and manufacturing facilities worldwide.