SGGW Scientists develop the waste heat recovery technology used in the production of stretch film from recycled materials
Scientists from the Institute of Mechanical Engineering, SGGW, have developed an innovative technology for recovering waste heat i.e., the process of heat integration during the production of stretch films. Previously, the heat energy was treated as production waste.
The innovative waste heat recovery system, managed by a developed industrial control system, allows the reusing of the heat energy that would be released into the atmosphere during the pre-processing of regranulate, a raw material for stretch film production.
The regranulate may consist of up to 80% of waste polyethylene. The technology was developed as part of research and development activities conducted together with TW Plast Sp. z o.o. [limited liability]. The technology allows for the management of waste, saves materials, reduces electricity consumption, and contributes to reducing the carbon footprint.
In addition to the original use of increased recycled material, enabling the production of high-quality stretch film, the process innovation lies in utilizing low-temperature waste heat, which is transformed into high-temperature heat energy and then used in the process of reglanulate drying.
The developed cascade heat pump system allows us to observe the increase in waste heat temperature. The heat pump system with a nominal cooling capacity of 220 kW, serving as the lower stage of the waste heat temperature recovery system, allows the increase in the waste heat temperature from 15°C to 32°C. The upper stage of the cascade, based on a compression heat pump with a nominal cooling capacity of 220 kW, allows an increase in the waste heat temperature from 32°C to 95°C.
Both heat pump systems are powered by environmentally friendly refrigerants, i.eOzone Depletion Potential (ODP) and Global Warming Potential (GWP) refrigerants.
The hydraulic system of the waste heat recovery line is managed by an industrial control system developed by the Department of Fundamentals of Engineering and Power Engineering. This system is based on supervisory control systems and subordinate control systems represented by the PLC (Programmable Logic Controllers). The supervisory control system includes a SCADA system comprising a computer and an HMI operator panel. Those innovative solutions were developed within a research and development project [POIR.01.01.01-00-1078/21] financed by the NCBR (National Centre for Research and Development), carried out by the Department of Fundamentals of Engineering and Power Engineering and TW Plast Sp. z o.o.
Expert advice by:
dr hab. Paweł Obstawski, prof. SGGW, Department of Fundamentals of Engineering and Power Engineering;
dr inż. Jacek Słoma, Institute of Mechanical Engineering, SGGW
