Cold Chain Technology Through the Lens of Thermal Engineering
“What is the problem that I am trying to solve? is the very first question that comes to my mind while attempting to unravel an engineering problem.”
Said Al Muzahimi - TSS Thermalist
April 30, 2024 | Thermalists
“What is the problem that I am trying to solve?
Quite broad, yet confined, this question constitutes many segments in the field of thermal engineering. Dealing with an invisible physical parameter, temperature, that we aim to control makes cold chain technology a unique application of thermal engineering.
Bounded by the limiting temperatures (the maximum and minimum), as a thermal engineer I find myself mainly tackling two challenges. The first one is developing a solution that would meet the duration requirement, and the second is attempting to maintain the internal temperature of the product above the minimum value of the tolerable temperature range, an issue we often refer to at the TSS Thermal Eco-Lab as ‘initial freezing.’
Developing a complete thermal solution means overcoming these two challenges. This always needs to be harmonic as the temperature of the product is influenced by different factors, which therefore alter the success rate of solving for each challenge. For example, if we were to add more iced gel packs, we would achieve longer duration. However, the probability that product temperature would be lower than the defined minimum value would be high, hence alleviating the risk of initial freezing. Conversely, if we were to increase buffer layers, like craft paper or corrugated sheets, between the product and the iced gel packs, we would find ourselves boosting the challenge of accomplishing the target duration requirement.
As a Thermalist at the TSS Thermal Eco-Lab, the way I visualize the problem is by recognizing the areas within a certain pack-out that are more prone to heat fluxes, while also taking into account that the product’s temperature is the highest priority. Of course, I also consider the time aspect of the solutions sensitivity towards heat fluxes; that is, during the initial periods of the test, and the very last phase of the test. Once we have overcome the initial freezing obstacle, the components of our solution would reach a state called thermal equilibrium at a specific temperature. This temperature is what the product and components of the pack-out would remain at for a specific period of time, up to a point where the transport of thermal energy from the external environment causes incremental changes in temperature. The amount of change is different for each component depending on their proximity to heat sources (the external environment), as well as intrinsic properties that are specific to each material, like specific heat.
TSS Thermalist Testing Services
- Be attentive to details in your system, no matter how small they might seem.
- By considering everything as heat loads or heat sinks, which really simplifies the process of understanding how you can approach the analysis of your system.
- Be flexible and adaptable when things do not go as you think they would theoretically.
- Every single material in your system contributes – perhaps not significantly, but they are still considerable in the over all system analysis.
- Do not limit yourself to the material’s properties while attempting to optimize a solution that you have. Sometimes, the optimization must be performed on the spatial aspect of the design (i.e, the placement of the system’s components and how they are arranged in space).
Now, to answer our question, “What is the problem that I’m trying to solve?”, that we introduced in the beginning of this discussion: My goal as a Thermalist at TSS is to utilize all possible factors that influence the product temperature for the purpose of keeping the equilibrium temperature of my system and the pack-out as intermediate as possible to the temperature bounds for a given period of time, as defined by the project requirements.
TSS Thermalist and Thermal Eco-Lab Capabilities
1. Testing
2. R&D
3. Competitive Analysis
4. Package-proofing
Perpetually we test using ISTA 7E Testing Standards for Thermal Transport Packaging, evaluating the effects of external temperature exposures on individual products that are packaged and shipped. We test thermal chambers and fluctuating temperatures through simulating environments. Then, we test packaging weight, box size, ice packs, insulation thickness – all in real life scenarios; no weak replications. We, of course, also employ the UPS Crush Test to ensure packaging robustness and cushioning capabilities.
