Experimental heat transformer monitoring based on linear modelling and statistical control process

In this paper the Statistical Process Control (SPC) methodology is used for first time to analyse the data obtained from an Absorption Heat Transformer (AHT), the aim in here is to define if the system was operated under statistical control using a Carnot Coefficient of Performance (COP) equal to 0.7 as an established specification. Data of a 10 kW prototype Single Stage Heat Transformer (SSHT) were analysed. Carrol/water mixture was used as a working pair in the thermodynamic cycle. The operating conditions of the SSHT under steady stated conditions show an energy recovery between 352.9 and 366.0 K, while waste energy is added from 339.1 to 361.9 K. Condenser temperature shows a process under statistical control; its Process Capability Ratio (Cp) is 1.15 dimensionless, and the Actual Process Capability Index (Cpk) is 1.11 dimensionless, as well. A linear modelling technique was used to control the SSHT. Finally, the COP variation is expressed as the absorber and generator linear functions, and evaporator temperatures are shown as techniques for SSHT control. The Cpk value indicates that the Condenser process has the ability to perform the specified operation of the SSHT.