Application Study On Large Temperature Difference In Chilled Water System Of The Air-conditioning

Chinese 11th 5—year—plan has been implemented, started from year 2006. During this period of time, energy issue is the focus because it has a huge impact on whether China can sustain the high speed growth rate on economy. Building energy consumption is about one third of energy consumption of the whole society , Air—conditioning energy consumption is about one half of building energy consumption. Recently, with the application of ice storage air-conditioning system, large temperature difference in water system of air-condition has been noticed as a new energy-saving technique.Large temperature difference in chilled water system of air—conditioning is the focus of this thesis,most study on: ①Making investigation of operation datum with ten typical public buildings in Shanghai.② Making experiments on large temperature difference of chilled water system and the practical office building. ③Analyzing and Avaluating the energy consumption of FCU system on different operation modes.④According to ASHRAE Toolkit model, experiment datum and product stylebook, analyses the feasibility of stable temperature difference, variable flow operating in chillers. This thesis mainly gives four conclusions as follows: ①The operation mode of large flow and low temperature difference is very common in practical samples and chillers capacity are more greater than on-peak load as same as pumps. The flow control of FCU is very important in partial load. ② The quantitaive analysis about influence of the capability for large temperature difference in chilled water on removing heat and humidity of AC terminal. The characteristic of water temperature control valve is researched through experment ,and the feasibility and energy-saving effect is also be confirmed.③According to the method of partial load rate, the best control method for energy-saving is suiting the temperature deference between supply and return to partial load. ④Chiller could satisfy varible flow (constant temperature difference) control at partial load with allowed cooling water flow and more saving-energy than constant flow control(varible temperature difference). The quantitaive analysis and the qualitative analysis about influence of the capability for large temperature difference in chilled water are studied.Energy-saving of large temperature difference in chilled water system of air—conditioning and the influence on the side of AC terminal and chiller are both researched with the quantitaive analysis and the qualitative analysis.The conclusions gets from upwards research have generalsignificance and offering the foundation for the more research in the future.