Project 2: Air-conditioning facility Statement An air-conditioning facility installed in Barcelona, Spain , shown in Figure...

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Project 2: Air-conditioning facility Statement An air-conditioning facility installed in Barcelona, Spain , shown in Figure 3, is composed of an air- cooled chiller, a chilled water pump, a fan and a heat exchanger. The initial design has the following characteristics (Task2a in the Modelica .mo input file provided with the coursework brief): • Air-cooled liquid chiller with R134a refrigerant and the nominal capacity of 743.7 kW. • Constant speed chilled water pump which keeps the constant chilled water volume flow rate in the chilled water loop of 115 m³/h (0.032 m³/s or mass flow rate of 32 kg/s). • Constant speed air fan which keeps the constant outdoor air volume flow rate of (13.33 m³/s or mass flow rate of 16 kg/s). • The chilled water temperature leaving the chiller (and entering the cooling coil water side), tch out is controlled to a fixed setpoint of 7 C. The system as designed operates with a variable temperature of the air delivered to the conditioned space (and leaving the cooling coil - air-side), t which fluctuates between 8 C and 10°C during most of the warm season period. Air-cooled chiller Due to persistent complaints from occupiers of the conditioned space about non-comfortable conditions caused by the cold air draft, a consultant (you) has been appointed to modify the system to operate with the fixed temperature of the air delivered to the conditioned space, setpoint is set to 13 C. tair out. The desired fixed You decide to analyse two possible system modification scenarios: tch out To conditioned space air_out tair_out Cooling coil Figure 3: Air-conditioned system (initial design) Barcelona, Spain 48 000 m³/h Chilled water pump Fan Outside air Project 2: Air-conditioning facility Statement An air-conditioning facility installed in Barcelona, Spain , shown in Figure 3, is composed of an air- cooled chiller, a chilled water pump, a fan and a heat exchanger. The initial design has the following characteristics (Task2a in the Modelica .mo input file provided with the coursework brief): • Air-cooled liquid chiller with R134a refrigerant and the nominal capacity of 743.7 kW. • Constant speed chilled water pump which keeps the constant chilled water volume flow rate in the chilled water loop of 115 m³/h (0.032 m³/s or mass flow rate of 32 kg/s). • Constant speed air fan which keeps the constant outdoor air volume flow rate of (13.33 m³/s or mass flow rate of 16 kg/s). • The chilled water temperature leaving the chiller (and entering the cooling coil water side), tch out is controlled to a fixed setpoint of 7 C. The system as designed operates with a variable temperature of the air delivered to the conditioned space (and leaving the cooling coil - air-side), t which fluctuates between 8 C and 10°C during most of the warm season period. Air-cooled chiller Due to persistent complaints from occupiers of the conditioned space about non-comfortable conditions caused by the cold air draft, a consultant (you) has been appointed to modify the system to operate with the fixed temperature of the air delivered to the conditioned space, setpoint is set to 13 C. tair out. The desired fixed You decide to analyse two possible system modification scenarios: tch out To conditioned space air_out tair_out Cooling coil Figure 3: Air-conditioned system (initial design) Barcelona, Spain 48 000 m³/h Chilled water pump Fan Outside air

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