地下防护工程空调相变储热水池储热性能实验研究

Performance of the Phase Change Heat Storage Air-Conditioning Reservoir for Underground Protective Engineering

针对既有地下防护工程传统空调冷却水池储热能力不足,外置冷却塔易造成工程红外暴露而影响工程安全的问题,提出了采用空调相变冷却水池方案以期增强系统储热能力,延长工程隔绝防护条件下空调系统运行保障时间.搭建了地下防护工程空调相变储热水池实验台,研究了定负荷条件下相变储热单元用量、冷却水流量对相变储热水池储热性能的影响;考虑添加相变储热单元对水池储热能力与连续保障能力的影响,提出了地下防护工程空调相变储热水池储热性能评价指标:相变储热水池单位体积储热量和基于出口温度定义的相变储热水池保障效能系数.研究表明:向地下防护工程空调储热水池中加入相变单元能够提升空调储热水池储热能力;与未加入相变储热单元的空调储热水池相比,当相变储热单元体积占空调储热水池有效容积的2.84%、4.26%时,相变储热水池单位体积储热量分别提高了6.35%和9.03%,相变储热水池保障效能系数分别提高了7%和11%,空调系统运行保障时间分别延长了1.77h和2.82h;在实验条件下,流速从250L/h提高至450L/h时,水池单位体积储热量和保障效能系数均有所降低,大流量工况(450L/h)下,相变储热单元存在未完全融化,水池储热能力与连续保障能力明显降低,因此在不影响热泵机组正常运行和水池储热性能的情况下,适当降低冷却水流量对空调储热水池储热系统是有益的.

Aiming for the insufficient thermal storage capability of the traditional air-conditioning reservoir and the problem of engineering safety caused by infrared exposure on the external cooling tower for existing underground protective engineering,the phase change storage reservoir scheme is proposed to strengthen the thermal storage capability and to prolong the run time of the HVAC system under the isolation protection condition. An experiment on the phase change heat storage air-conditioning reservoir was conducted,and the effects of the quantity of the phase change heat storage unit and the water mass flow on the capability of the reservoir are analyzed under the fixed load condition. To analyze the effects of the phase change heat storage unit on the heat storage capacity and continuous safeguarding capacity of the reservoir,the following performance parameters of the phase change heat storage reservoir for underground protective engineering are proposed:Heat storage capacity per unit volume and safeguarding efficiency of the phase change heat storage pool. The results show that adding the phase change heat storage unit can significantly improve the heat storage capacity of the reservoir. Compared with the reservoir without phase change heat storage unit,when the volume of the phase change heat storage unit accounts for 2.84% and 4.26% of the effective volume of the reservoir,the heat storage capacity per unit volume of the phase change heat storage reservoir is increased by 6.35% and 9.03%,the guaranteed efficiency coefficient of the phase change heat storage reservoir is increased by 7% and 11%,and the guaranteed operation time is prolonged by 1.77h and 2.82 h,respectively. Under the experimental conditions,when the flow rate is increased from 250 L/h to 450 L/h,the heat storage capacity per unit volume and guaranteed efficiency coefficient are both reduced. When the flow rate is high (450 L/h),the phase change heat storage units do not melt completely and the heat storage capacity and guaranteed continuous capacity of the pool are significantly reduced. Therefore,properly reducing the cooling water flow rate is beneficial to the heat storage system of the reservoir without affecting the operation of the heat pump unit and the heat storage performance of the reservoir.