# Study on the Dynamic Generation of Subcooled Water Using a Compact Heat exchanger
## 3 Experimental Results and Analysis  
### Experimental Results  
#### 3.1.1 Subcooled Water with Different Subcooling Degrees  
The magnitude of the subcooling degree of the subcooled water determines the ease of its conversion into ice or ice slurry after release through subcooling. The greater the subcooling degree is, the higher the energy (latent heat) will be, and the easier it will be to release the subcooled water through small perturbations. Figure 3 shows the experimental results of four subcooling degrees achieved according to the experimental conditions. The results illustrate that the compact heat exchanger is suitable for the dynamic generation of subcooled water, and Figure 3a shows that the system reached the higher level of current subcooled water engineering applications for dynamic ice storage systems (2 K) [7; 22]. Any 0.1 K increase in the subcooling degree is difficult to achieve. Figure 3b-d show our explorations aiming to continuously increase the subcooling degrees and duration time, according to which the subcooling degree increases by 1.5 K compared to Figure 3a. Additionally, the system can maintain stable subcooled water generation for a certain period under the experimental conditions shown in Figure 3b,c. Under the experimental conditions in Figure 3d, the subcooling degree reaches 3.6 K. At subcooling degrees no greater than 3 K, the relative duration of the water's subcooling is longer. At more than 3.5 K, the duration decreases. Compared with the previous three results, this demonstrates that it is easier to convert water into ice or ice slurry after releasing the subcooled water, while the duration time is significantly shorter, and heat exchange channel blockage occurs earlier and more frequently. Figure 3: Experimental results. (**a**) \(-2.1\)\({}^{\circ}\)C subcooled water. (**b**) \(-2.4\)\({}^{\circ}\)C subcooled water. (**c**) \(-3\)\({}^{\circ}\)C subcooled water. (**d**) \(-3.6\)\({}^{\circ}\)C subcooled water. The high frequency of fluctuations in the outlet water temperature is an impact of the inlet temperature (thermostatic accuracy) and K-type thermocouple temperature measurement of the outlet water temperature (small changes in the direction of water flow). This has an effect on the increase in the subcooling degree and the duration. During the dynamic generation of the supercooled water, fluctuations in the inlet parameters cause simultaneous changes in the outlet parameters, whereby the inlet temperature parameters vary more than the flow rate. This occurs as a result of the combined effects of the accuracy of the thermostatic device for both loop sides and heat loss in the pipeline due to environmental changes. Therefore, the subcooled water must undergo a non-constant process of temperature fluctuation with time from the beginning of the process to the constant generation stage, which lasts for approximately 180 s. The parameters of the experiments undergo minor changes as the subcooled temperature enters the constant generation stage. In this experimental study, the dynamically generated subcooled water was disturbed by the energy of the free-falling impact and ice slurry formed after the release of the subcooled water. Stalactite-like icicles formed as part of the continuous accumulation of the subcooled water. Their properties were soft and mud-like, and they contained water. As shown in Figure 4, the upper part of the icicles was drier and resembled snow, while the lower part consisted of a high water content, possessing a dark color and being ice-like. The experiment was conducted during summer, no air-conditioning system was set up, and the ice storage tank was insulated, even though it was a low-temperature environment. The generated ice or ice slurry partially melts, thus maintaining the low-temperature conditions in the tank. Ice slurry generation requires two conditions: the subcooling degree and the duration.