10 min.
ramps-up in less than 10 minutes
0-3 GWP
can operate with natural refrigerants
90°C
can produce up to 90°C heat or even higher
Plug-in
possible to integrate into
the existing plant
How does a heat pump work?
An electrically driven heat pump functions via a vapor compression cycle. At the core of this process is a substance called a refrigerant, which within this closed system experiences phase transitions. At low pressure, the refrigerant boils as it absorbs energy from the heat source. A compressor then increases the pressure by about three to seven times. The high-pressure refrigerant releases thermal energy mainly through condensation. The refrigerant then passes through an expansion device, which reduces the pressure back to a low level. By utilizing electricity as a driving force for the compressors, the cycle repeats, transferring heat from a low-temperature source to a high-temperature sink.
Heat pump sizing principles
As with any investment, achieving optimal performance is crucial, and this is particularly true for heat pumps. The dynamic nature of heat pump technology demands careful consideration. Specifically, heat pumps operate at peak efficiency when the heat source temperature is at its maximum and the heat sink temperature is at its minimum. This characteristic has significant implications for the sizing strategy.
A few points for consideration:
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The balance point refers to the specific outdoor air temperature at which a heat pump is designed. As temperatures drop, the heat output of a heat pump typically decreases. While it is technically possible to design a system that relies entirely on a heat pump, achieving 100% coverage is often not economically viable, as the system would be over-engineered for the relatively few hours of extreme cold.
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The operational envelope of a heat pump system must be carefully evaluated to ensure consistent performance under all conditions. During the design phase, a thorough understanding of the heating system network and the behavior of the chosen heat source is essential. This insight is crucial for selecting a suitable heat pump plant.
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Heat exchanger efficiencies are critical in the design of an industrial heat pump. Each degree increase in evaporation temperature can improve efficiency by approximately 3-4%, and similarly, each degree reduction in condensation temperature impacts efficiency. Therefore, it is essential to identify and design for the optimum point tailored to the specific requirements of each individual plant.
Heat pumps vs. Boilers
In comparison to a boiler, a heat pump can significantly reduce energy consumption and greenhouse gas emissions. As shown in the chart, a heat pump with a COP of 3 is much more energy-efficient than an industrial boiler with an efficiency of 0.95 (95%). While the cost of electricity is often higher than the alternative heat source, the energy tariff ratio is an essential factor to consider when evaluating the economic feasibility of a heat pump.
Natural refrigerants
Heat pump technology uses a fluid contained in a closed system, and while there may be no performance issues, fluids leaking into the atmosphere have a negative effect on global warming and health. To minimize the impact on the environment, natural refrigerants such as carbon dioxide (CO2), ammonia (NH3) or hydrocarbons are preferred over synthetic substances. It guarantees a completely sustainable solution in the long term.
Environmental Impact
Greenhouse gas emissions from electricity generation vary depending on the power plant location. In the EU27 countries, the average emission of CO2 per kWh of electrical energy produced is 230 gCO2. In comparison, the GHG emissions for gas is estimated to be around 202 gCO2 per kWh of gas energy value. It's important to understand the carbon footprint of a heat pump and compare it to a gas boiler. Therefore, using the same energy usage as in the previous example, and with reference to carbon intensity values, we can assess the environmental impact of the heat pump versus the gas boiler.
What may go wrong?
An industrial heat pump represents a well-proven technology, with some plants installed 40 years ago still in operation.
However, risks exist with any technology. A major risk involves poor integration into the existing site. If the desired supply temperature and capacity are not achieved despite a successful Factory Acceptance Test, the problem must be identified on-site.
Another long-term issue can stem from a poor choice of refrigerant. Each unit is designed for a specific refrigerant, and switching afterward is not an option. Synthetic refrigerants negatively impact global warming and human health. Opting for a natural refrigerant that best fits the operating conditions is a wiser choice.
An oversized heat pump leads to wasted capital and may underperform at part-load conditions. Determining the optimum size before the design phase is crucial to overcoming this barrier.
Efficiency issues can stem from various sources. These may include suboptimal heat exchanger dimensioning, poor oil management, or a configuration that is not the best fit for the operating envelope.
Invest in planning and save much more!
Failing to plan is planning to fail. Any overlooked aspect specific to the technology can have a significant negative impact. The best solution to overcome any of potential risks is to invest in planning.
EKA is a specialized engineering team with a dedicated focus on heat pump and refrigeration systems. Engage EKA as your independent consultant from the initial planning phase to gain a competitive edge for your project. We design custom, manufacturer-neutral solutions for your system, ensuring the optimal choice and driving a highly competitive procurement process.