A new PCM application turned up in my LinkedIn feed this week:
"Pluss Advanced Technologies Pvt. Ltd. presents ThermoTab active plates used for both #coldstorages and #transportation applications at India Cold Chain Show 2018" ... "Enabling last mile connectivity with fuel free refrigeration."
The post offered plenty of hashtags but not much information. I asked Vishnu Sasidharan, right, vice president for new product initiatives at Pluss, for details on the thermoTab Active heat exchanger.
Q: Who developed the thermoTab Active heat exchanger and when was it introduced commercially?
A: "The thermoTab Active heat exchangers are being sourced from FIC, Italy, a company which is has been manufacturing heat exchangers for thermal energy storage in refrigerated vehicles since 1951. Pluss has partnered with FIC to offer complete solution – PCM-filled heat exchangers exclusively in India – introduced commercially in India from September 2017. The partnership leverages FIC & Pluss strength in heat exchanger and material sciences respectively to offer solutions for storage, transportation and space cooling/heating."
Q: What types of PCM are used? (salt hydrate, thermal energy capacity, peak melt point ranges, etc.)
A: "The current standardized offerings are for two categories of temperature; +2 to +8 deg C and -15 to -25 deg C. The plates offered on the basis heat load capacities and the categories under which it falls. For instance, if a customer requires 20kw-Hr of thermal storage capacity for +2 to +8 deg C the number of plates, the customer could refer to the datasheet and choose the combination of thermoTab Active plates based on its capacity. Alternatively, the datasheet also provides with a quick selection of number of thermoTab Active plates based on the volume of the container, insulation thickness and the retention hours required."
Q: Describe how the heat exchanger functions.
A: "The heat exchanger plates have a refrigerant coil inside. The PCM filled inside the plate remains completely immersed in the PCM solution. During charging or freezing cycle begins when refrigerant is passed through the coil at a temperature lower than the phase change point of PCM. When the temperature in the room starts to rise above the phase change point of the PCM, the surface of the heat exchangers starts to release the energy at a constant temperature, thereby maintaining the temperature of the environment."
Q: How and when are the PCM panels charged in a refrigerator truck?
A: "The thermoTab Active plates are charged by means of an electric refrigeration system on board the truck. Prior to commencement of the delivery cycle, the truck’s refrigeration system is connected to a three-phase electric source for 8-10 hours. The cost of storing energy by electricity as against active cooling using diesel the savings are substantial. The payback for such system is less than six months."
Q: How and when are the PCM panels charged in a micro cold room?
A: "In a micro cold room as well the charging takes place similar to a refrigerator truck. However, the operating cost could be further reduced by running the refrigerator unit using solar instead of grid electricity. The thermoTab Active plates provides a unique value proposition for solar based micro cold room by enabling 24/7 uninterrupted cooling without the requirement of an electrochemical battery. Most micro cold rooms operate in areas which do not have access to electricity."
Q: How does thermoTab Active differ from passive PCM systems used in reefer trucks and cold rooms?
A: "Passive PCM systems depend on a centralized freezing unit. This makes the process cumbersome for the user as the PCM modules/cartridges need to be constantly removed from the container to a freezer unit and back. It also results in temperature losses due to exposure to ambient temperature during the loading and unloading of PCM modules."
Q: How many refrigerator trucks are using the system?
A: "In India over 250 refrigerator trucks are using this system."
Q: How many micro cold units are using the system?
A: "In India approximately 60 micro cold rooms are using this system. The demand is immense and we believe the application is now beginning to transition from early stage to maturity in terms of market reach."
Q: Is the product available outside India?
A: "It is also available in Africa and southeast Asia."