储能科学与技术 ›› 2021, Vol. 10 ›› Issue (5): 1768-1776.doi: 10.19799/j.cnki.2095-4239.2021.0334

• 物理储能十年专刊·储热 • 上一篇    下一篇

新型地下跨季节复合储热系统性能规律

徐德厚1(), 周学志1(), 徐玉杰2,3, 左志涛1,2,3, 陈海生1,2,3()   

  1. 1.毕节高新技术产业开发区国家能源大规模物理储能技术研发中心,贵州 毕节 551712
    2.中国科学院工程热物理研究所,北京 100190
    3.中国科学院大学,北京 100049
  • 收稿日期:2021-07-12 修回日期:2021-07-23 出版日期:2021-09-05 发布日期:2021-09-08
  • 作者简介:徐德厚(1990—),男,硕士,实验师,研究方向为大规模物理储热,E-mail:shadehi@163.com|周学志,高级工程师,研究方向为储热技术和压缩空气储能技术,E-mail:zhouxuezhi@iet.cn|陈海生,研究员,研究方向为新型大规模储能技术、传热与储热(冷)特性等,E-mail:chen_hs@iet.cn
  • 基金资助:
    贵州省科学技术基金(黔科合基础[2017]1163);贵州省大规模物理储能技术研发平台能力建设(黔科合服企[2019]4011);大规模物理储能国家地方联合工程研究中心(发改办高技[2019]180号);贵州省平台及人才团队建设计划项目(黔科合平台人才[2017]5308);贵州省科技支撑项目(黔科合支撑[2020]2Y064);博士后科研工作(流动)站(黔科合平台人才[2019]5622)

Performance law of a new composite seasonal underground thermal storage system

Dehou XU1(), Xuezhi ZHOU1(), Yujie XU2,3, Zhitao ZUO1,2,3, Haisheng CHEN1,2,3()   

  1. 1.National Energy Large Scale Physical Energy Storage Technologies R&D Center of Bijie High-tech Industrial Development Zone, Bijie 551712, Guizhou, China
    2.Institute of Engineering Thermophysics, Chinese Academy of Science, Beijing 100190, China
    3.University of Chinese Academy of Science, Beijing 100049, China
  • Received:2021-07-12 Revised:2021-07-23 Online:2021-09-05 Published:2021-09-08

摘要:

可再生能源受天气、地域、季节限制,具有间歇性和不稳定性属性,从而导致供需不匹配,跨季节储热是解决上述问题的有效方法。然而,传统地下跨季节储热具有储热方式单一、热量损失大等缺点,本文将水箱储热和地埋管储热相结合,组成新型跨季节复合储热系统。建立并通过实验验证了复合储热系统模型,在此基础上,分析了储/释热质量流量、储热体模匹配、地埋管数量和层间距以及土壤热导率等参数对储热体温度、储/释热量、储/释热功率和热量损失等的影响规律。结果表明,随着储/释热质量流量的增加,系统效率也逐渐增加;储热体规模匹配α值增加,系统效率随之上升,但水箱体积占比的提高,会导致热量损失增大,故储热体规模匹配需综合考虑,既要能达到较高的系统效率,获得较大的储/释热功率,又需尽量减少投资成本,同时降低热量损失;提高地埋管数量,有利于增加储/释热量,提升系统效率;地埋管层间距的增大,增加了储热体土壤体积,从而降低了储热温度,不利于释热的进行,导致系统效率降低;土壤热导率的增加,强化了土壤间热量传递,地埋管储热功率增加,储热峰值温度也因此提高,然而热量散失也加快,释热功率显著降低,导致系统效率下降。

关键词: 地下储热, 跨季节储热, 复合储热, 地埋管储热, 水箱储热, TRNSYS

Abstract:

Renewable energy is characterized by intermittency and instability because of weather, region, and season, resulting in a mismatch between supply and demand. Seasonal thermal storage is an effective technology to solve the abovementioned problems. However, the traditional seasonal underground thermal storage has the disadvantages of single storage modes and severe heat loss. In this study, the underground hot water energy storage (HWES) and borehole thermal energy storage (BTES) modes were combined to establish a composite seasonal thermal storage system, and a numerical model was developed and confirmed by comparing with experiments. On this basis, the effects of parameters, such as store/release flow rate, scale matching, number of boreholes, and soil thermal conductivity, on the temperature, thermal energy store/release capacity and power, and heat loss of the composite system were analyzed. The performance law of the composite thermal storage system was examined to maximize efficiency. The results show that with an increase in the store/release mass flow rate, the system efficiency gradually increases. The system efficiency increases with an increase α value of scale matching. However, an increase in the volume ratio of the water tank causes more heat loss. Therefore, scale matching should be comprehensively considered not only to achieve higher system efficiency and obtain larger heat store/release power but also to minimize investment cost and reduce heat loss. Increasing the number of buried pipes increases the thermal energy store/release capacity and improves the system efficiency; however, it increases the investment cost. An increase in the space between the borehole rings increases the soil volume, thus reducing the storage temperature, which is not conducive to energy release and decreases the system efficiency. With an increase in the soil thermal conductivity, heat transfer in the soil, energy store power of boreholes, and peak temperature of energy storage increase. However, heat loss becomes faster, and the energy release power decreases, thereby decreasing the system efficiency.

Key words: underground thermal storage, seasonal thermal storage, composite thermal storage, borehole thermal energy storage (BTES), hot water energy storage (HWES), TRNSYS

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