Study On Measurement And Verification Methods Of The Chilling Water System Retrofitting In Air-conditioning Systemm

The Oversized capacity of air-conditioning equipment and the weak, or missed,control system have significant impact on the building energy consumption that can bereduced by Energy Management Contract (EMC). Both the building owner and servicesupplier can benefit from EMC whose essential issue is to precisely predict real energyconservation. As regards the frequency converting of cooling water pump, one ofeconomical energy saving retrofitting measure, this dissertation proposes the method toassess the energy savings:①By literature review this paper analyses how variable cooling water impacts theperformance of pumps, cooling tower and plants. Furthermore, the boundary involvingthe energy saving assessing, is supposed to necessarily contain pumps and plants.②By literature this paper summarizes the commonly used methods for convertingthe frequency of cooling water pump, including Constant-Temperature-Differencemethod, Constant-Outlet–Flow-Temperature method and optimal method. Differentmethod has different impact on performance of plants. Besides, how to distribute thecooling loads between plants is concluded as three methods: One-By-One, averagedmethod, and optimal method. Different method decides energy consumption of plants.③Based on IMPVP this paper proposed the formula, principle andvariable-measuring method for energy saving assessing. The typical conditions areinvestigated using a project that the author participated in.④This paper summarizes methods for obtaining the air-conditioning loads, andtheir uncertainty.⑤Adopting the plants model validated with on-site measured data, this paperstudies the COP and flow rate under four typical situations and different frequencyconverting methods. The simulation results are used to generate formulas for COP andcooling water flow rate with their uncertainty. Furthermore, the total uncertainty of plantenergy consumption is investigated.⑥This paper proposes method for predicting energy consumption of the pump andits uncertainty. Combined with the uncertainty of energy consumption of plants, thetotal uncertainty of energy saving assessing is studied to recommend the appropriatemethod for air-conditioning loads predicting, COP and flow rate predicting. These recommendations will greatly instruct and facilitate the future projects.