中文摘要：

首先,通过对电热水器加热过程热平衡方程的解析,导出壳体内水温在加热过程中的理论计算公式.在此基础上,提出电热水器水温加热到设定温度所需加热时间与加热能耗的理论预测模型,并通过计算值与实测值对比,验证预测模型的有效性.最后,通过对不同工况的计算,考察不同因素对加热时间和加热能耗的影响.研究结果表明：随着水容量和设定温度的提高,加热时间和加热能耗显著增加;初始水温提高,加热时间和加热能耗明显减少;加热功率增加,加热时间呈指数减少,加热能耗减少不明显;保温性能和环境气温的提高有助于减少加热时间和加热能耗.

英文摘要：

The thermal balance equation of heating process of electric water heater during the un-draining period was analyzed,the calculation formula of water temperature was derived,then the prediction model of heating time and energy consumption was put forward.Through the comparison between calculation results and test results,the validity of the prediction model was verified.By case calculations under different condition,the effect of different factor on heating time and energy consumption was investigated.It shows that：as the water capacity and set temperature increase,the heating time and energy consumption increase obviously;as the initial water temperature increases,the heating time and energy consumption decrease significantly;as the heating power increases,the heating time decreases exponentially,but the energy consumption reduces little;the better thermal insulation and higher air temperature are conducive to reduce the heating time and energy consumption.