Chiller unit

Water dried, carbon dioxide and hydrogen sulphide free gas i.e. wet-gas, is chilled (typically to about -35°C) and enters the bottom of the absorber tower there are usually two absorber towers. Condensate separated in the chiller unit leaves the bottom of the tower, the gas rises against a chilled falling solvent that has entered the top of the tower (the lean-oil). The solvent absorbs the heavier constituents while the lighter sales gas rises to the top of the absorber and exits the top of the tower. The now rich-oil is collected on an absorber tray above the gas entry point and passes via heat exchangers to a column (ROD). 

Figure 11.1 Pressure temperature profiles of the absorption chiller unit.

Problem 6.31 The process shown in Figure 6-iq is part of a chiller unit that uses water as the refrigerant. The following data are available stream 1 is a vapor-liquid mixture at 0.5 bar stream 5 is saturated vapor at 5 C stream 6 is at 500 C stream 7 is at 100 C. Calculate the following on the basis of 1 kg/s of water in stream 1 ... 

The aim of this work is to develop and validate an expert system, by means of Bayesian networks, able to support the health monitoring process of a chiller unit, suitably manufactured for this research scope. 

The model development has been carried out by a test case that was a small chiller unit for water cooling purposely developed for experimental activity. The equipment consists of two circuits the refrigerant line and the water line and it is monitored by about ten sensors that include temperatures, pressures, levels and power supplies (on/off). The sensors signals are monitored by an acquisition card and transmitted to a pc for the intelUgent elaboration. The test bed has been developed to simulate about eight failure modes hut in this work we investigated only six of them. 

We experienced the expert system by means of some runs, where we simulated some failures that can occur in the chiller unit. With those failure information, we train the network and this way we learn the structure and parameters of the Bayesian network. Once obtained the network, the diagnosis probabilistic inference wiU give us the component failure probabilities according to the evidences that show up in our entrance sensors. 

The aircooled water chiller units (chiller) for the water cooled VSD are equipped with with centrifugal fans for indoor installation. The chiller has a closed water circulation system that circulates water to the drive WCU. The chiller rated data is shown in Table 6. 

The BTRS makes use of a temperature-dependent ion exchange process to store boron and release boron to the RCS without discharging water to the BRS for later evaporation. The BTRS, which operates in conjunction with the CVCS, consists mainly of several demineralizers, a chiller unit, a chiller pump, heat exchangers, a BTRS recirculation pump, a BTR... 

There should also be prepared a mechanical/instrumental catalogue, containing specific drawings and/or data about plant items like compressors, chiller unit, dosing pumps, transfer pumps, main equipment items like sulphur burner, converter tower, drying equipment, reactors, mixers, etc. etc., instruments and control system. 

Figure 8.22 Fouled chiller unit. (Courtesy of Defence R D, Canada-Atlantic)...

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