PhD Thesis - Energy Systems Research Unit - University of Strathclyde

duct 2 via the air node in the cooling coil. The water flow, on the other hand, is sentfrom the node in Water pipe 1 to the node in Water pipe 2 via the water node in thecooling coil. The interaction between the air and water node of the cooling coilaccounts for the energy transfer between the air and the water flow.Fig. 3.1 - Plant system connections in ESP-rOnce all the links between the different components have been established, thesurrounding conditions in terms of air temperature (outside air temperature or zonetemperature) can be selected for each individual plant component. This is particularlyimportant in terms of describing any potential heat loses from plant components. Thefinal part requires the user to specify which components inside the plant network arelinked to the individual building zones, e.g. supply and exhaust ducts, radiators, etc.In order to control the output of the plant system and hence match it with the energydemands of the individual zones, a control scheme is associated with the plantnetwork. For each component which needs to be controlled, a control scheme isdefined featuring a sensor (e.g. a temperature sensor sensing the temperature of aparticular zone in a building model), an associated actuator which responds to asignal from a controller (e.g. a centrifugal fan) and a control loop (e.g. a simple‘On’/‘Off’ or a more complex Proportional/Integral/Derivative [PID] control).3.2.2 Basic plant configurationThe base case plant configuration used in the simulations (described in Chapter 5) isshown in Figure 3.2. All of the components shown, except for the absorption chiller,were already present in the ESP-r plant library. As will be explained in Section 3.3 anew dynamic absorption chiller model had to be developed for this thesis.97