Analysis of air conditioning heat recovery system for reducing reheat energy

doi:10.16085/j.issn.1000-6613.2018-0486

Abstract

Abstract: In order to reduce the reheat energy consumption in air handling unit of the primary return air system, two novel improved heat recovery systems (mixed air heat recovery system and fresh-return air heat recovery system) were proposed in this paper. Based on the analysis of the air handing process of air conditioning system, combined with the first law of thermodynamics and the heat mass transfer equation of air handling unit, the energy consumption calculation model of these two heat recovery systems was set up. Taking Kunming area as an example, the energy consumption and the energy saving rate change of the heat recovery system were studied by the effects of outdoor enthalpy, indoor heat and moisture ratio, fresh air volume and supply air volume. Compared with common return air heat recovery system and the primary return air system, the results showed that these two novel heat recovery systems in the temperate region can both reduce about 60% energy consumption than the primary return air system. These two novel heat recovery can eliminate the phenomenon of "hot and cold offset" in primary return air system. These two novel heat recovery systems can effectively reduce the initial investment of heat exchanger, and shorten the payback period of heat recovery investment.

Key words: gas, thermodynamics process, recovery, heat transfer, primary return air system, plate-fin heat exchanger, temperate region

摘要： 为降低一次回风全空气空调系统空气处理机组再热能耗，提出两种改进空调热回收系统，分别是混风热回收系统和新回风热回收系统。基于空调系统空气处理流程的分析，结合热力学第一定律、空气处理机热质传递方程，建立了这两种空调热回收系统能耗的计算模型。在此基础上，以昆明地区为例，考察了空调室外新风参数、空调区域热湿比、新风量及送风量等主要因素对热回收系统能耗与效率的影响，并与常用回风热回收系统和一次回风系统进行了比较。研究结果表明，在温和地区采用新提出的两种热回收系统均比一次回风系统节能60%左右，消除了一次回风全空气系统存在的“冷热抵消”现象；新提出的两种热回收全空气系统能有效减少换热器初投资，缩短热回收设备投资回收期。

关键词: 气体, 热力学过程, 回收, 传热, 一次回风空调系统, 板翅式换热器, 温和地区

CLC Number:

WANG Weiwei, WANG Huitao, HAN Jinrong, GE Zhong, HUANG Jinglun. Analysis of air conditioning heat recovery system for reducing reheat energy[J]. Chemical Industry and Engineering Progress, 2018, 37(11): 4181-4189.

王维蔚, 王辉涛, 韩金蓉, 葛众, 黄靖伦. 降低再热能耗的空调热回收系统分析[J]. 化工进展, 2018, 37(11): 4181-4189.

References

[1] 江宇, 黄溢, 葛天舒, 等. 新型热湿独立控制空调系统的实验研究[J]. 化工学报, 2014, 65(s2):188-194. JIANG Yu, HUANG Yi, GE Tianshu, et al. Novel temperature and humidity independent control system[J]. CIESC Journal, 2014, 65(s2):188-194.
[2] 李浩亮, 徐晓军, 赵志伟, 等. 基于计算流体力学的高大空间温湿度控制模型的建立[J]. 烟草科技, 2017, 50(6):73-80. LI H L, XU X J, ZHAO Z W, et al. Modeling of temperature and humidity control in high and large space based on computational fluid dynamics[J]. Tobacco Science & Technology, 2017, 50(6):73-80.
[3] 张小芬. 卷烟厂空调系统负荷特性及新型中央空调系统研究[D]. 上海:东华大学, 2012. ZHANG X F. Studies on load features of air conditioning system and novel central air conditioning system in cigarette factory[D]. Shanghai:Donghua University, 2012.
[4] 段未, 马国远, 周峰. 多回路泵驱动回路热管系统的换热特性[J]. 化工学报, 2017, 68(1):104-111. DUAN Wei, MA Guoyuan, ZHOU Feng. Heat transfer characteristics of multi-loop pump-driven loop heat pipe system[J]. CIESC Journal, 2017, 68(1):104-111.
[5] 段未, 马国远, 周峰. 泵驱动回路热管能量回收装置性能的影响因素[J]. 化工学报, 2016, 67(10):4146-4152. DUAN Wei, MA Guoyuan, ZHOU Feng. Factors influencing energy recycle performance of pump-driven heat pipe loop device[J]. CIESC Journal, 2016, 67(10):4146-4152.
[6] RAMADAN M, ALI S, BAZZI H, et al. New hybrid system combining TEG, condenser hot air and exhaust airflow of all-air HVAC systems[J]. Case Studies in Thermal Engineering, 2017, 10:154-160.
[7] KHALED M, RAMADAN M. Heating fresh air by hot exhaust air of HVAC systems[J]. Case Studies in Thermal Engineering, 2016, 8:398-402.
[8] CUCE P M, CUCE E. Toward cost-effective and energy-efficient heat recovery systems in buildings:thermal performance monitoring[J]. Energy, 2017, 137:487-494.
[9] CUCE P M, RIFFAT S. A comprehensive review of heat recovery systems for building applications[J]. Renewable & Sustainable Energy Reviews, 2015, 47:665-682.
[10] ALONSO M J, LIU P, MATHISEN H M, et al. Review of heat/energy recovery exchangers for use in ZEBs in cold climate countries[J]. Building & Environment, 2015, 84:228-237.
[11] PLOSKIC A, WANG Q. Evaluating the potential of reducing peak heating load of a multi-family house using novel heat recovery system[J]. Applied Thermal Engineering, 2018, 130:1182-1190.
[12] 王帅. 成都地区排风热回收适宜性的动态分析[D]. 成都:西南交通大学, 2015. WANG S. Dynamic analysis of exhaust air heat recove suitability in Chengdu[D]. Chengdu:Southwest Jiaotong University, 2015.
[13] 施睿华. 上海地区公共建筑采用排风热回收装置的节能性[J]. 暖通空调, 2017, 47(9):92-95. SHI R H. Energy saving performance of exhaust air heat recovery system in Shanghai public buildings[J]. Heating Ventilating & Air Conditioning, 2017, 47(9):92-95.
[14] 刘思梦, 康国青, 李德英. 热管式排风热回收在厦门地区的适用性分析[J]. 建筑节能, 2014(8):56-59. LIU S M, KANG G Q, LI D Y, et al. Applicability analysis of heat pipe type exhaust heat recovery for buildings in Xiamen[J]. Building Energy Efficiency, 2014(8):56-59.
[15] ZHANG Ziyang, ZHANG Chunlu, GE Meicai, et al. A frost-free dedicated outdoor air system with exhaust air heat recovery[J]. Applied Thermal Engineering, 2018, 128:1041-1050.
[16] 周智勇, 吴青青, 韦中师, 等. 二次热回收热管式空调系统[J]. 化工学报, 2017, 68(5):1823-1832. ZHOU Z Y, WU Q Q, WEI Z S, et al. Secondary heat recovery heat pipe air conditioning system[J]. CIESC Journal, 2017, 68(5):1823-1832.
[17] 钟珂, 赵敬德, 亢燕铭. 空气换热器在冷却顶板空调系统中的节能潜力[J]. 暖通空调, 2010, 40(4):125-130. ZHONG K, ZHAO J D, KANG Y M. Energy saving potential of air heat exchanger in chilled ceiling air conditioning systems[J]. Heating Ventilating & Air Conditioning, 2010, 40(4):125-130.
[18] 肖武, 王开锋, 阮雪华, 等. 序列数编码的遗传算法柔性优化多股流板翅式换热器通道排列[J]. 化工进展, 2016, 35(5):1353-1359. XIAO Wu, WANG Kaifeng, RUAN Xuehua, et al. Flexible optimization of passage arrangement for multi-stream plate-fin heat exchangers using genetic algorithm with ordinal[J]. Chemical Industry and Engineering Progress, 2016, 35(5):1353-1359.
[19] 胡金鹏, 崔国民, 胡向柏. 板翅式全热交换器的结构优化[J]. 化工进展, 2010, 29(s1):650-652. HU J P, CUI G M, HU X B. Structural optimization of a plate-fin type total heat exchanger[J]. Chemical Industry and Engineering Progress, 2010, 29(s1):650-652.
[20] CHURITTER Tösha. An investigation into the pressure drop optimisation of air-air plate-fin heat exchangers through the application of compact advanced pin surface technology[J]. Annals of Neurology, 2014, 53(2):267-270.
[21] HAZARIKA S A, DESHAMUKHYA T, BHANJA D, et al. Thermal analysis of a constructal T-shaped porous fin with simultaneous heat and mass transfer[J]. Chinese Journal of Chemical Engineering, 2017, 25(9):1121-1136.
[22] 刘景成, 张树有, 徐敬华, 等. 板翅换热器导流结构非线性映射与性能多目标优化[J]. 化工学报, 2015, 66(5):1821-1830. LIU Jingcheng, ZHANG Shuyou, XU Jinghua, et al. Non-linear mapping and multi-objective optimization of leading flow structure in plate-fin heat exchanger[J]. CIESC Journal, 2015, 66(5):1821-1830.
[23] 杨辉著, 文键, 童欣, 等. 板翅式换热器锯齿型翅片参数的遗传算法优化研究[J]. 西安交通大学学报, 2015, 49(12):90-96. YANG Huizhu, WEN Jian, TONG Xin, et al. Optimization design for offset fin in plate heat exchanger with genetic algorithm[J]. Journal of Xi'an Jiaotong University, 2015, 49(12):90-96.
[24] 史美中, 王中铮. 热交换器原理与设计[M]. 5版. 南京:东南大学出版社, 2014. SHI Meizhong, WANG Zhongzheng. Principle and design of heat exchanger[M]. 5th ed. Nanjing:Southeast University Press, 2014.
[25] 赵荣义, 范存养, 钱以明, 等. 空气调节[M]. 4版. 北京:中国建筑工业出版社, 2009. ZHAO Rongyi, FAN Cunyang, QIAN Yiming, et al. Air conditioning[M]. 4th ed. Beijing:China Architecture & Building Press, 2009.
[26] 国家发展和改革委员会. 综合能耗计算通则:GB/T2589-2016[S]. 北京:中国标准出版社, 2016. National Development and Reform Commission. General rules for calculation of comprehensive energy consumption:GB/T2589-2016[S]. Beijing:China Standard Press, 2016.
[27] 中华人民共和国住房和城乡建设部.民用建筑供暖通风与空气调节设计规范:GB50736-2012[S]. 北京:中国建筑工业出版社, 2012. Ministry of Housing and Urban and Rural Construction in People's Republic of China. Design code for heating ventilation and air conditioning of civil buildings:GB50736-2012[S]. Beijing:China Architecture & Building Press, 2012.