Abstract: For controlling energy transfer (Q) of a thermal energy exchanger of an HVAC system, a control system determines flow-dependent model parameters (M) for modelling performance of the thermal energy exchanger, using a plurality of measurement data sets, each measurement data set including for a respective measurement time a value of a measured flow of fluid (?act), a value of a measured supply temperature (Tsup) of the fluid, and a value of the measured return temperature (Tret) of the fluid. The control system calculates an estimated energy transfer (Qest) of the thermal energy exchanger, using the flow-dependent model parameters (M), and controls (S4) the energy transfer (Q) of the thermal energy exchanger by regulating (S5) the flow of fluid (?) through the thermal energy exchanger, using the estimated energy transfer (Qest).

Abstract: The present invention provides a reactor system for producing polycarbonate. The reactor system has one or more reactant vessels, an oligomerization reactor, a first pressure control device, a preheater, a second pressure control device, a distributor, and a flash tank. The one or more reactant vessels contain reactants contain a melt transesterification catalyst, a dihydroxy compound, and an activated diaryl carbonate. The reactor system is connected in the following configuration: (i) the one or more reactant vessels connected to the oligomerization reactor, (ii) the first pressure control device disposed between and connecting the outlet of the oligomerization reactor and the inlet of the preheater; (iii) the second pressure control device disposed between and connecting the outlet of the preheater and the distributor; and (iv) the distributor disposed at the inlet to the flash tank.