Yulong Ding, the University of Birmingham professor who directed the development of a rail/truck shipping container designed to keep perishables cold without a power supply, says his team developed an organic phase change material with enhanced thermal properties for the project. The PCM is designed to keep the temperature inside the container between 5 and 12˚ C for up to 120 hours. Ding, director of the university's Center for Energy Storage, provided additional detail on the project in an interview this week.
Q: Describe your organization's role in the project.
A: It was funded by CRRC Shijiazhuang, a Chinese railway equipment manufacturer, and the project was collaborative. Our work at Birmingham included PCM materials development and fabrication, cold storage device design and testing, cold charging method and design. Work began in October 2017.
Q: What role did CRRC Shijiazhuang play?
A: CRRC was the project sponsor. Their work included manufacture and test of the device and cold charge device, installation of cold storage devices into large container, data-logging and IT, real application demonstration and testing (35,000 km combined road and railway testing across a wide climate zones).
Q: Can you briefly describe the testing methods and results?
A: I believe two standard containers were used, goods include all sorts of vegetables, flowers and fruits. Energy saving data have not been processed for the real tests but we do have testing data from labs, which is around 20 percent.
Q: Describe the PCM used in the application.
A: We used organic based PCM reformulated for enhanced thermal properties. Melting temperatures can be turned between -4 and 4 degree C, and the thermal storage capacity is >~200 kJ/kg.
Q: How big are the rail containers, typically, and how much PCM is used in each container?
A: We used the standard container for road transportation, which can be used for rail use. I prefer not to say the amount of PCM used, which may need approval from our sponsor.
Q: How is the PCM charged, and how long does it take to charge the PCM in a typical container?
A: We have a mobile charge device. The charging time is relatively short. The details will need our sponsor to approve before I can tell.
Q: In what material is the PCM contained (HDPE, film, metal)?
A: We used composite PCM contained in PCM storage device.
Q: How is the PCM deployed in the rail containers?
A: The PCM devices are installed inside the container.
Q: Does CRRC plan to manufacture the rail containers?
A: I doubt they would make the container.