Research On Energy Efifciency Operating Characteristics Of Chiller In Air-conditioning

With the development of China’s urban construction, reducing chiller energyconsumption of air conditioning system becomes the key problem to be solved. Chiller energyconsumption can not only be affected by it own, but also by its operating conditions. However,the chillers which were already used in existing buildings have unchangeable unitperformance parameters. So it seems more particularly significant to optimize the operatingparameters.In this paper, in the way of univariate analysis and multivariate analysis were used andresearched on the chiller coefficient of performance and its influencing factors. Relationshippolynomials and curves were obtained respectively: relationship between chiller COP and unitload ratio, that between chiller COP and the temperature difference of supply and returnchilled water, that between chiller COP and chilled water flow. Through calculation ofsensitivity coefficient, unit loading ratio is determined to be the most sensitive factor whichcan affect the COP of the chiller. Operating characteristics of chiller in the condition of partialload were simulated and researched with example.Through DeST, a kind of energyconsumption analysis software, some parameters, such as hourly cooling load and timefrequency of air-conditioning system in a partial load condition were calculated. Inaccordance with the results of load calculation, different chillers configuration and operationcontrol mode were selected and matched. the specific power and chillers total energyconsumption under the condition of partial load and different configuration and operationcontrol mode were calculated and combined, so the optimal configuration and operationcontrol mode in different chiller loads were obtained.Through the regression and sensitivity analysis on influencing factors of chiller COP andsimulated research on operating characteristics of chiller in the condition of partial load,settled the relationship polynomials between chiller COP and its influencing factors, andobtained the results of unit load ratio was the most sensitive factor; at the same time, theconfiguration of a large cooling capacity chiller and a small cooling capacity chiller alongwith the operation control mode of one by one starting become more energy saving, whenchiller operated in the condition of partial load. The research results of the subject can offersome reference for energy efficiency operation of chiller in project.