纳米流体的低温蓄冷释冷特性及其谷电蓄冷应用研究_刘玉东

第35卷第11期中国电机工程学报V ol.35 No.11 Jun.5, 2015

2015年6月5日Proceedings of the CSEE ©2015 Chin.Soc.for Elec.Eng. 2779 DOI：10.13334/j.0258-8013.pcsee.2015.11.016 文章编号：0258-8013 (2015) 11-2779-09 中图分类号：TK 124

纳米流体的低温蓄冷释冷特性

及其谷电蓄冷应用研究

刘玉东，李鑫

(低品位能源利用技术及系统教育部重点实验室(重庆大学)，重庆市沙坪坝区 400044)

Cold Charge and Discharge Characteristics of Nanofluids and Its Application to Ice Storage

Using Valley Electricity

LIU Yudong, LI Xin

(Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, Ministry of Education (Chongqing University),

Shapingba District, Chongqing 400044, China)

ABSTRACT: Low-temperature ice storage using valley electricity in industry is an effective measure for power demand side management. However, the supercooling degree of the existing ice storage materials is so high that the energy efficiency ratio of refrigeration unit is too low. In this paper, TiO2-BaCl2-H2O nanofluid with good suspension stability was prepared by adding TiO2 nanoparticles in BaCl2-H2O eutectic salt solution. The cold charge and discharge characteristics of TiO2-BaCl2-H2O nanofluid and BaCl2-H2O eutectic salt solution were studied experimentally in an ice storage system. The results indicated that the supercooling degree of nanofluid was greatly reduced, and the cold charge/discharge rate and the cold charge/discharge capacity of nanofluid increase greatly than that of the BaCl2-H2O eutectic salt solution. Furthermore, nanofluid was helpful to enhance the overall heat transfer coefficient. As a practical application, TiO2-BaCl2-H2O nanofluid is used in the low-temperature ice storage system in Chongqing beer factory, and the operation results indicate that the peak load shifting effect is remarkable and the payback period is only 22 months, which verified that TiO2-BaCl2-H2O nanofluid is an important potential candidate in industrial low-temperature ice storage area.

KEY WORDS: nanofluids; eutectic salt solution; cold charge; cold discharge; heat transfer enhancement

摘要：工业用谷电低温蓄冷是电力需求侧管理的一项有效措施，但现有蓄冷材料的过冷度太高，导致制冷机组的能效比

基金项目：国家自然科学基金项目(51276204)；中央高校基本科研业务费专项项目(CDJZR10140004)。

Project Supported by National Natural Science Foundation of China (51276204); The Fundamental Research Funds for the Central Universities (CDJZR10140004). 太低。文中在BaCl2-H2O共晶盐水溶液中添加TiO2纳米粒子，制备成悬浮稳定的TiO2-BaCl2-H2O纳米流体蓄冷材料，在蓄冷装置中对TiO2-BaCl2-H2O纳米流体与BaCl2-H2O共晶盐水溶液进行蓄冷和释冷对比实验，结果表明：TiO2-BaCl2-H2O纳米流体的过冷度受到极大抑制；蓄冷时，TiO2-BaCl2-H2O纳米流体冻结完成时间比BaCl2-H2O共晶盐水溶液大大提前，蓄冷率和蓄冷量均大幅度提高；释冷时，前者比后者的释冷速度快，单位时间内释放的冷量多。对蓄冷系统的传热分析表明，纳米流体有助于强化系统的总传热系数。在重庆啤酒厂的低温蓄冷系统中采用TiO2-BaCl2-H2O 纳米流体，其移峰填谷效果显著，投资回收期仅22个月，说明TiO2-BaCl2-H2O纳米流体是一种很有潜力的工业用低温蓄冷材料。

关键词：纳米流体；共晶盐；蓄冷；释冷；强化传热

0 引言

随着我国经济的高速发展，电网的负荷越来越重，同时峰谷负荷差也越发突出[1-2]。具有移峰填谷作用的冰蓄冷技术，作为需求侧管理的主要措施之一，目前受到业界广泛关注[3]。但是，冰蓄冷技术目前主要应用于蓄冷温度不低于0℃的中央空调行业[4-9]，而更具有广阔应用背景的蓄冷温度低于0℃的工业低温冰蓄冷[10]则长期受到忽视。如果在工业企业中采用低温冰蓄冷技术，其投资回收期要比中央空调蓄冷短得多，因为工业用制冷机组采用低温冰蓄冷技术后，制冷主机满负荷运行，提高了机组的能效比和设备的利用率，而且工业蓄冷的装机容量巨大，能削减更多的高峰负荷和最大程度的利用分时电价政策，为用户节省更多的运行电费。因