Design and Techno-economic Analysis of a Cold Storage for an innovative Cooling System from IceHeart AB
Development of Disruptive Cooling and Freezing Technology at Iceheart AB
Iceheart AB strives for Efficiency and Resilience in the Cold Chain of the Food Sector, delivering innovative cooling, freezing and cold storage solutions. The proposed thesis project is proposed by Iceheart, with the details as follows.
Background and Problem Statement
A secure and continuous electricity supply is essential for maintaining the integrity of the modern food supply chain, particularly with regard to refrigeration and freezing systems. Disruptions in the power grid have proven to have far-reaching consequences for the food sector, where temperature control is critical in preventing quality degradation, foodborne illnesses, and economic losses. One striking example occurred in April 2025, when a large-scale power outage affected major parts of Spain. For an entire day, sections of the retail sector were left without electricity, resulting in the spoilage of large quantities of refrigerated and frozen goods. According to media reports, the financial losses amounted to several hundred million euros (El País, 2025).
The food industry relies heavily on functional cold chains—from production and transport to retail and consumption. According to the International Institute of Refrigeration (2022), up to 20% of global food losses can be attributed to inadequate refrigeration. This corresponds to multi-billion-euro losses annually, while also exacerbating the environmental impact due to increased food waste (Food and Agriculture Organization of the United Nations [FAO], 2021). In regions with unstable power infrastructure, vulnerability is especially high, where even short-term outages can result in disproportionately severe consequences.
Against this backdrop, the demand for resilient and energy-efficient refrigeration systems is becoming increasingly urgent. Iceheart AB has developed an innovative thermal energy storage (TES) technology based on phase change materials (PCMs), which enables cooling even without a continuous power supply. This technology has the potential to represent a paradigm shift in sustainable cooling, especially in power-constrained environments and applications requiring stable temperature control. However, further development and validation are needed—particularly concerning cooling and freezing applications, secondary cooling loops, and system integration.
Project Description
The purpose of this thesis is to evaluate Iceheart’s technology in comparison with existing refrigeration and freezing solutions. The study is conducted as a comparative methodology project, focusing on energy efficiency, cost-effectiveness, system resilience, and the capacity to maintain cold chain functionality during power outages.
Research Questions:
for a thermosyphon-based secondary loop sub-zero cooling system (using Iceheart technology) with a 26 kWh cooling capacity:
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what are the optimal PCMs?
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what are the available freezing system configurations using PCM-TES and other TES designs in the market as well as in research and development phases (i.e., in literature) today?
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what are the suitable thermosyphon-based freezing system configurations using PCM-TES designs for Iceheart technology?
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what are the key performance indicators (KPIs) concerning technical and economic performance of such freezing storage system
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how does the optimal design perform considering the identified KPIs and the available designs from literature?
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What is the optimal PCM-TES design for the chosen thermosyphon-based cooling system configuration employing Iceheart technology, per the KPIs?'
Company Background – Iceheart
Iceheart AB has developed a patented and potentially disruptive technology for cooling and freezing across a broad range of industrial applications. The system enables environmentally sustainable and cost-effective energy storage, manages load fluctuations without requiring peak compressor capacity, and is particularly well-suited for off-grid scenarios (Li et al., 2019; Wang et al., 2019). Iceheart currently provides commercial cooling solutions and is in the process of extending its technology to freezing applications, which requires the development of low-temperature PCMs and their integration into secondary cooling loops (Zhang et al., 2016). In parallel, compliance with EU regulations regarding refrigerants must be ensured (European Commission, 2024).
Objectives
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Identify and evaluate suitable PCMs for low-temperature TES
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Select the appropriate PCMs for use in thermosyphon-based secondary loops within the specified temperature range
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Map the available technical solutions today for cooling and freezing systems with PCM-TES and other TES types, in the market and also in research and development phases
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Design several configurations of a thermosyphon-based cooling system employing Iceheart technology, using a TES with the chosen PCM-TES for a peak cooling capacity of 26 kWh for the temperature range of -12 to -17 °C.
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Identify the key performance indicators (KPIs) concerning technical and economic performance of such freezing storage system
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Evaluate the techno-economic performance of the designed system configurations with PCM-TES against these chosen techno-economic KPIs
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Benchmark key system KPIs against existing and available technical and market solutions
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Propose the most optimal system design with an optimal design of a PCM-TES solution
Scope Limitations
The project is limited to commercial freezing and the transportation of deep-frozen food products.
Methodology
This thesis combines theoretical analysis with technical design and evaluations combined with material and technology review on PCM-Based cold TES. Key methodological components include:
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Literature review of suitable PCMs for TES in cooling and freezing applications
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Literature review of PCM -TES used with thermosyphon systems for cooling and freezing applications, also identifying the relevant techno-economic Key Performance Indicators (KPIs)
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Perform engineering calculations with numerical modelling for system and TES sizing under varying operational conditions, for the planned capacity of 26 kWh
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Perform a simple economic analysis on the system design, considering both the investment and operational costs and savings, and other relevant KPIs
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Benchmark the system design against the techno-economic KPIs defined
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Present the optimal thermosyphon-based cooling system design configuration with optimal PCM and TES sizing
Logistics and Collaboration
The thesis will be conducted primarily remotely, with on-site visits within Sweden when appropriate. Iceheart’s teams are based in Stockholm and Örebro, and the technical advisor is located in southern Sweden. Iceheart technology has been tested in laboratory conditions at SWEGON, and these results are available for reference.
Supervisor and examiner at KTH
Supervisors
Olof Källgren – Engineer, available as supervisor
Minanda Fritz – M.A., KTH mentor program
Pärlan Fritz – CEO, company contact/supervisor
References
European Commission. (2020). Energy resilience and the importance of critical infrastructures.
European Commission. (2024). EU rules on fluorinated greenhouse gases.
Grand View Research. (2024). Europe cold storage market size & outlook, 2024–2030.
International Institute of Refrigeration. (2022). The role of refrigeration in worldwide nutrition.
Ken Research. (2024). Europe cold chain market outlook to 2028.
Zhang, Y., Lin, K., & Jiang, Y. (2016). Thermal performance of PCM-based systems in secondary cooling loops. Journal of Building Performance, 7(1), 88–95