Latest project results
The Indus3Es Absorption Heat Transformer (AHT) technology.
In its final year, the Indus3Es project worked very hard on the AHT technology reaching many challenging goals in order to reduce the primary energy consumption of industries in order to increase their effectiveness and competitiveness. The project AHT is designed for recovering and revalorizing the industrial waste heat below 130°C and to revalorize almost the ~ 50% of recovered waste heat, boosting the temperature and becoming usable in the industrial process again.
The indus3Es Pilot demonstrator 200 kW revalued heat machine is equipped with an innovative non-condensable gasses (NCGs) purge system. This system requires no additional equipment, it is fully automated and has a negligible impact on the AHT performance. A very low-flow vapor bleed line delivers vapor and NCGs from the high-pressure vessel to the low-pressure vessel. And from there an additional line sucks vapor and NCGs to the adiabatic absorption chamber (AAV). The AAV attains the lowest pressure in the system by using portion of the strong solution, which is subcooled by the water-solution heat exchanger (WSHX). The removed subcooling heat is transferred to the refrigerant, therefore it is internally recuperated is not considered a loss. The NCGs which are collected in the AAV are trapped there and are periodically transferred to the evacuation vessel (EV). The EV is then isolated from the AHT, and its NCGs content is discharged into the atmosphere. No special ejectors are use and no vacuum pump is needed. For this procedure, only the opening and closing of valves in the correct sequence and timing is required. This is fully automated by the control system.
Indus3Es AHT beyond the State of the Art.
The Indus3Es will demonstrate the operation of a minimum scalable AHT in a real industrial environment. The knowledge of the absorption chillers ongoing development has been transferred to the AHT technology, implementing several innovations:
- The implementation of two adiabatic absorption operation modes: Atomizing spray nozzles and a drip distribution system in which the liquid solution in the tray is exposed to the vapor – promoting adiabatic absorption. For demonstration and research purposes, the atomizing spray mode can be toggled on or off. Measurements from the Lab- and Breadboard-Scale high-pressure vessels have demonstrated that these modes perform as intended by increasing the maximum obtainable temperature within the absorber.
- Innovative motor-less non-condensable gases purge system: Presence of non-condensable (NC) gases critically reduces the absorption process which is critical for the AHT. The innovative system for removal of NCs developed in Indus3Es continuously gathers and traps NCs in a dedicated vessel, which are then periodically and automatically discharged to the environment. This solution is simple, inexpensive, and efficient, compared to other known options.
- Indus3Es AHT behavior automatic control: The control system has been designed considering especially the “Characteristic Equation Method” approach. Apart from the desirable performance automatic adjustment procedures, an attention to anti-crystallization procedure has been considered, which is potentially riskier for AHTs, compared to absorption chillers. By the end of the project, a tested control system will have been installed and operated for several months. This will demonstrate the successful integration and automation of the technology and its innovations in a real industrial application.
Next to the AHT technology itself concepts for the implementation of the AHT technology into modern industrial environments were developed. In the Indus3Es case all challenges of the implementation in a refinery with the high security requirements especially in explosive environments were overcame.