Research Article

An Optimal Hybrid Control Method for Energy-Saving of Chilled Water System in Central Air Conditioning

Table 1

Symbols and values of parameters in cold capacity transfer process.

Parameter (Description)Value

indoor hear capacity, (KJ/K)469
specific heat of air, (kJ/kgk)1.01
specific heat of water, (kJ/kgk)4.186
temperature of fresh air, (°C)26
setting temperature, (°C)25
indoor initial temperature, (°C)30
volume of sending air, (kg/s)0.623
temperature of walls, windows, and roof, respectively, (°C)35,36,35
area of walls, windows, and roof, respectively, , (m2)80,5,0
heat transfer coefficient of walls, windows, and roof, respectively, , (W/m2k)0.047,0.054,0.051
latent heat load, (W)25
random heat load, (W)30
return air rate, 0.85
transfer efficiency from water system to air system, 0.9
ratio of cooling capacity allocation, 7%
temperature difference, (°C)6
rated power, respectively, P0 (kW)1.69;2.17;4.91;10.6
rated flow, respectively, (L/s)0.61;0.75;1.77;4.17