SCIENCE CHINA Technological Sciences, Volume 61 , Issue 2 : 219-231(2018) https://doi.org/10.1007/s11431-017-9121-6

Experimental study on the new type of electrical storage heater based on flat micro-heat pipe arrays

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  • ReceivedJun 25, 2017
  • AcceptedAug 16, 2017
  • PublishedSep 13, 2017


A new type of electrical storage heater that utilizes latent heat storage and flat micro-heat pipe arrays (FMHPAs) was developed. The thermal characteristics of the heater were tested through experimentation. The structure and operating principle of the storage heater were expounded. Three rows of FMHPAs were applied (three rows with five assemblies each) with a mass of 28 kg of phase change material (PCM) in the heat storage tank. Electric power was supplied to the PCM in the range of 0.2‒2.04 kW, and air was used as heat transfer fluid, with the volume flow rate ranging from 40‒120 m3/h. The inlet temperature was in the range of 15‒24°C. The effects of heating power, air volume flow rate, and inlet temperature were investigated. The electrical storage heater exhibited efficiencies of 97% and 87% with 1.98 and 1.30 kW of power during charging and discharging, respectively. Application of the proposed storage heater can transfer electricity from peak periods to off-peak periods, and the excess energy generated by wind farms can be stored as heat and released when needed. Good economic and environmental benefits can be obtained.

Funded by

Scientific Research Project of Beijing Educational Committee(004000546315527)

National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2012BAA13B02)

Graduate Science and Technology Foundation of Beijing University of Technology(ykj201600060)


[1] Gao F S. Haze weather, environment and energy: The strategies of HVAC industry (in Chinese). Heat Vent Air Cond, 2013, 9: 33‒47. Google Scholar

[2] Ma X Q, Liu Z, Zhao X Y, et al. The spatial and temporal variation of haze and its relativity in the beijing-tianjin-hebei region (in Chinese). Areal Res Dev, 2016, 35: 134‒138. Google Scholar

[3] Gao Z, Chen D M, Yang J H, et al. Study on rural low-voltage distribution network planning with coal-to-electricity project (in Chinese). Electrotech Electr, 2015, 5: 1‒5. Google Scholar

[4] The Beijing News, 2015. Rural "coal to electricity" subsidies will be unified with the city (in Chinese). http://news.xinhuanet.com/energy/2015-04/06/c_127660081.htm. Google Scholar

[5] China Economic Net, 2013. 2015 residential electricity will be fully implemented peak and valley price (in Chinese). http://finance.ce.cn/rolling/201312/26/t20131226_1998315.shtml. Google Scholar

[6] Han D, Cai X G. Short-term scheduling of hydrothermal power system considering environmental protection and time-of-use price (in Chinese). Power Syst Technol, 2009, 14: 78‒83. Google Scholar

[7] Tan Z F, Chen G J, Qi J X, et al. Research on time-of-use price at generation side based on optimal configuration of power resources (in Chinese). Power Syst Technol, 2008, 7: 61‒65. Google Scholar

[8] Pei Z Y, Dong C, Xin Y Z. Review of operation and management of integrating wind power in China (in Chinese). Electr Power, 2010, 11: 20. Google Scholar

[9] Yang S F. Heat storage system with abandon of a wind power plant in Inner Mongolia (in Chinese). Build Energ Env, 2015, 2: 103‒105. Google Scholar

[10] Pazouki S, Haghifam M R. Optimal planning and scheduling of energy hub in presence of wind, storage and demand response under uncertainty. Int J Electrical Power Energ Syst, 2016, 80: 219-239 CrossRef Google Scholar

[11] National Energy Administration, 2016. Wind power grid operation in 2016 (in Chinese). http://www.nea.gov.cn/2017-01/26/c_136014615.htm. Google Scholar

[12] Dunn B, Kamath H, Tarascon J M. Electrical energy storage for the grid: a battery of choices. Science, 2011, 334: 928-935 CrossRef PubMed ADS Google Scholar

[13] Blarke M B, Yazawa K, Shakouri A, et al. Thermal battery with CO2 compression heat pump: Techno-economic optimization of a high-efficiency Smart Grid option for buildings. Energ and Buildings, 2012, 50: 128-138 CrossRef Google Scholar

[14] Jamieson N V, Sundberg R, Lindell S, et al. Preservation of the canine liver for 24–48 hours using simple cold storage with UW solution. Transplantation, 1988, 46: 517-522 CrossRef Google Scholar

[15] Jia J, Wan Y, Shou W W, et al. Ice storage system of China Pavilion in EXPO 2010 (in Chinese). Refrig Air Condit, 2012, 6: 100‒103. Google Scholar

[16] Li G, Hwang Y, Radermacher R. Review of cold storage materials for air conditioning application. Int J Refrigeration, 2012, 35: 2053-2077 CrossRef Google Scholar

[17] Sun Y, Wang S, Xiao F, et al. Peak load shifting control using different cold thermal energy storage facilities in commercial buildings: A review. Energ Conv Manage, 2013, 71: 101-114 CrossRef Google Scholar

[18] Dinker A, Agarwal M, Agarwal G D. Heat storage materials, geometry and applications: A review. J Energ Institute, 2015, 90: 1-11 CrossRef Google Scholar

[19] Gao Y F, Sun Y J. Application of the electric-boiler thermal storage for heating in air-conditioning system (in Chinese). Energ Eng, 2002, 2: 28‒31. Google Scholar

[20] Ip K, Gates J. Thermal storage for sustainable dwellings. In: Proceedings of Sustainable Building, Maastricht, Netherland, 2000. Google Scholar

[21] Sharma A, Tyagi V V, Chen C R, et al. Review on thermal energy storage with phase change materials and applications. Renew Sustain Energ Rev, 2009, 13: 318-345 CrossRef Google Scholar

[22] Al-Abidi A A, Bin Mat S, Sopian K, et al. Review of thermal energy storage for air conditioning systems. Renew Sustain Energ Rev, 2012, 16: 5802-5819 CrossRef Google Scholar

[23] Lu Y W, Yu Q, Du W B, et al. Natural convection heat transfer of molten salt in a single energy storage tank. Sci China Technol Sci, 2016, 59: 1244-1251 CrossRef Google Scholar

[24] Shang B, Ma Y, Hu R, et al. Passive thermal management system for downhole electronics in harsh thermal environments. Appl Thermal Eng, 2017, 118: 593-599 CrossRef Google Scholar

[25] Xia S J, Chen L G, Sun F R. Entransy dissipation minimization for liquid-solid phase change processes. Sci China Technol Sci, 2010, 53: 960-968 CrossRef Google Scholar

[26] Zhang G W, Hu P, Liu M H. Thermal performances of non-equidistant helical-coil phase change accumulator for latent heat storage. Sci China Technol Sci, 2017, 60: 668-677 CrossRef Google Scholar

[27] Hadjieva M, Kanev S, Argirov J. Thermophysical properties of some paraffins applicable to thermal energy storage. Sol Energ Mater Sol Cells, 1992, 27: 181-187 CrossRef Google Scholar

[28] Himran S, Suwono A, Mansoori G A. Characterization of alkanes and paraffin waxes for application as phase change energy storage medium. Energ Sources, 1994, 16: 117-128 CrossRef Google Scholar

[29] Alkan C. Enthalpy of melting and solidification of sulfonated paraffins as phase change materials for thermal energy storage. ThermoChim Acta, 2006, 451: 126-130 CrossRef Google Scholar

[30] Farid M M, Husian R M. An electrical storage heater using the phase-change method of heat storage. Energ Conv Manage, 1990, 30: 219-230 CrossRef Google Scholar

[31] Zhao J, Zhou Z C, Pu Y L, et al. Design and application of electric heating high temperature phase change energy storage device (in Chinese). Agric Eng, 2016, 6: 98‒102. Google Scholar

[32] Wang X, Liu J, Zhang Y, et al. Experimental research on a kind of novel high temperature phase change storage heater. Energ Conv Manage, 2006, 47: 2211-2222 CrossRef Google Scholar

[33] Ma G Y, Wang Z H, Yan R S, et al. Making and capability testing of electric heater with phase change accumulator (in Chinese). J Fushun Pet Inst, 2003, 3: 50‒53. Google Scholar

[34] Zhao Y H, Zhang K R, Diao Y H. Heat pipe with micro-pore tubes array and making method thereof and heat exchanging system. U.S. Patent, US20110203777 A1, 2011-8-25. Google Scholar

[35] Xie J C, Wang Z, Zhou X. Intelligent power measuring instrument (in Chinese). China Patent, CN201773152 U, 2011-3-23. Google Scholar

[36] Gill R S, Singh S, Singh P P. Low cost solar air heater. Energ Conv Manage, 2012, 57: 131-142 CrossRef Google Scholar

[37] Zhao Y H, Wang J Y, Diao Y H, et al. Heat transfer characteristics of flat micro-heat pipe array (in Chinese). CIESC J, 2011, 62: 336‒343. Google Scholar

[38] Chen J H, Bo Y J, Li P S, et al. The emission characteristic of air pollutants from civil furnace in Beijing (in Chinese). In: Proceedings of the 10th National Conference on Atmospheric Environment, Nanning, China, 2003. 303‒307. Google Scholar

[39] Ye J D, Zhang Y J, Jiang J Y, et al. Comparison and analysis about mound coal and raw coal for rural heating (in Chinese). Build Energ Effic, 2016, 11: 102‒103. Google Scholar

[40] Lv K F, Tong L G, Yi S W, et al. Analysis and application of heating control strategy of off-peak electricity heating system (in Chinese). Heat Refriger, 2013, 9: 64‒66. Google Scholar

[41] He P. Heating engineering (in Chinese). 4th ed. Beijing: China Building Industry Press, 2009. 167. Google Scholar

[42] Qiu J D. Research on rural heating mode (in Chinese). Rural Electrif, 2015, 10: 20‒20. Google Scholar

[43] Zhu T, Zhao Y, Diao Y, et al. Experimental investigation and performance evaluation of a vacuum tube solar air collector based on micro heat pipe arrays. J Cleaner Production, 2017, 142: 3517-3526 CrossRef Google Scholar

  • Figure 1

    (Color online) Structure of the storage heater and heat transfer unit.

  • Figure 2

    (Color online) Structure and operating principle of the FMHPA components.

  • Figure 3

    (Color online) Experimental system diagram.

  • Figure 4

    (Color online) Measuring point arrangement diagram.

  • Figure 5

    (Color online) Temperature curve along the Z direction of the No. 8 FMHPA assembly versus time in the charging and discharging processes.

  • Figure 6

    (Color online) Temperature curves along the X direction of Nos. 6‒10 FMHPA assemblies at different times in the charging process (a) and versus time in the discharging process (b).

  • Figure 7

    (Color online) Temperature curve along the Y direction of the No. 8 FMHPA assembly versus time in the charging and discharging process.

  • Figure 8

    (Color online) Electrical energy and average temperature of PCM versus time in the charging process.

  • Figure 9

    (Color online) Energy proportion in the charging process.

  • Figure 10

    (Color online) Curve of average temperature of PCM at different heating powers versus time.

  • Figure 11

    (Color online) Curve of charging completion time and charging efficiency at different heating powers.

  • Figure 12

    (Color online) Curve of inlet and outlet temperatures, extraction power and average temperature of PCM versus time.

  • Figure 13

    (Color online) Energy proportion in the discharging process.

  • Figure 14

    (Color online) Curve of average temperature of PCM at different volume flow rates of HTF versus time.

  • Figure 15

    (Color online) Curve of extraction power at different volume flow rates of HTF versus time.

  • Figure 16

    (Color online) Curve of average temperature of PCM at different inlet temperatures of HTF versus time.

  • Figure 17

    (Color online) Curve of extraction power at different inlet temperatures of HTF versus time.

  • Table 1   Thermal-physical properties of #52 commercial paraffin wax




    Phase transition temperature



    Latent heat of phase change



    Specific heat capacity



    Thermal conductivity



    Solid-state density



    Liquid-state density



  • Table 2   Experimental conditions during discharging process


    Inlet temperature (°C)

    Air volume flow (m3/h)

    Constant temperature test







    Constant flow test






  • Table 3   Model specifications and accuracy of the testing instrument

    Testing instrument

    Model specification


    Data collector

    Agilent 34970A




    Thermal resistance

    Pt100 WZPF-293

    0.15 + 0.2%|t|°C




    Electricity meter



  • Table 4   Uncertainty error of the calculated parameter





    Ec/d (Pc/d)

    7.05 (1.98)

    MJ (kW)


    η c




    Ee (Pe)

    6.27 (1.41)

    MJ (kW)


    η e




  • Table 5   Comparison of the pollutant emissions of electrical storage heating and coal stove heating

    Heating method


    CO2 (kg)

    SO2 (kg)

    NOx (kg)

    Coal stove heating

    4.45 × 1010

    1.44 × 108

    1.26 × 108

    Electrical storage heating




    Emission reductions

    4.45 × 1010

    1.44 × 108

    1.26 × 108

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