Research on Adsorption and Energy Storage of Refrigerants R1234yf and R32 in MOF-74
-
摘要: 利用流体分子在纳米多孔材料固体表面吸附分离过程中热能与表面能的相互转化，可以提高循环工质吸热量。采用分子模拟（分子动力学和巨正则蒙特卡洛）方法并结合吸附理论开展了R1234yf和R32在MOF-74中的吸附储能研究。在纯工质吸附中，发现R32在MOF中的吸附量高于R1234yf的吸附量。制冷工质在Zn-MOF-74中的吸附量比在Co-MOF-74中的吸附量大，且R1234yf达到饱和吸附所需的压力低于R32在相应吸附剂内达到饱和所需压力值。而在混合工质吸附中，R1234yf的吸附量高于R32的吸附量，随着温度的增加，R1234yf的吸附量呈现逐步上升的趋势，而R32则逐渐减少。经储能计算表明，M-MOF-74（M=Co, Zn）颗粒质量分数越高，混合工质相变所需吸收热能越多。Abstract: The heat absorption of circulating working medium can be improved by using the mutual transformation of thermal energy and surface energy in the process of adsorption and separation of fluid molecules on the solid surface of nano-porous materials. In this paper, molecular simulation (molecular dynamics and Grand Canonical Monte Carlo) and adsorption theory are used to study the adsorption and energy storage of R1234yf and R32 in MOF-74. In the adsorption of pure working medium, it is found that the adsorption capacity of R32 in MOF is higher than that of R1234yf. The adsorption capacity of refrigerant in Zn-MOF-74 is larger than that in Co-MOF-74, and the pressure required for R1234yf to reach saturation adsorption is lower than that required for R32 to reach saturation in the corresponding adsorbent. In the mixed working medium adsorption, the adsorption capacity of R1234yf is higher than that of R32. With the increase of temperature, the adsorption capacity of R1234yf shows a gradually increasing trend, while that of R32 gradually decreases. The energy storage calculation shows that the higher the mass fraction of M-MOF-74 (M = Co, Zn) particles, the more heat energy needed to be absorbed for the phase transition of the mixed working medium.
-
Key words:
- R1234yf /
- R32 /
- MOF-74 /
- Adsorption /
- Energy storage /
- Molecular simulation
-
图 5 R1234yf与R32混合工质在M-MOF-74中的吸附
Figure 5. Adsorption of Mixed Working Medium of R1234yf and R32 in M-MOF-74
图 6 3.5 MPa和5 MPa时含不同M-MOF-74质量分数的混合工质的储能百分比与温度差关系
Figure 6. Relationship between Energy Storage Percentage and Temperature Difference of Mixed Working Medium with Different Mass Fractions of M-MOF-74 at 3.5 MPa and 5 MPa
表 1 MD方法模拟的MOF-74内能值
Table 1. Internal Energy of MOF-74 Simulated by MD
温度/K 内能值（M=Co）/（kJ·kg−1) 内能值（M=Zn）/（kJ·kg−1) 293 −375152 −473556 313 −375103 −473477 333 −375055 −473399 353 −375006 −473321 373 −374957 −473242 393 −374908 −473164 
下载: 导出CSV
-
[1] WU C, XU X X, LI Q B, et al. Performance assessment and optimization of a novel geothermal combined cooling and power system integrating an organic flash cycle with an ammonia-water absorption refrigeration cycle[J]. Energy Conversion and Management, 2021, 227: 113562. doi: 10.1016/j.enconman.2020.113562 [2] 陈晓雪,刘朝,李期斌,等. 混合工质(R227ea/R245fa)有机朗肯循环的动态特性研究[J]. 工程热物理学报,2020, 41(7): 1604-1611. [3] CHEN X X, LIU C, LI Q B, et al. Dynamic behavior of supercritical organic Rankine cycle using zeotropic mixture working fluids[J]. Energy, 2020, 191: 116576. doi: 10.1016/j.energy.2019.116576 [4] WANG S K, LIU C, REN J Z, et al. Carbon footprint analysis of organic Rankine cycle system using zeotropic mixtures considering leak of fluid[J]. Journal of Cleaner Production, 2019, 239: 118095. doi: 10.1016/j.jclepro.2019.118095 [5] SUN Z, LIU C, XU X X, et al. Comparative carbon and water footprint analysis and optimization of Organic Rankine Cycle[J]. Applied Thermal Engineering, 2019, 158: 113769. doi: 10.1016/j.applthermaleng.2019.113769 [6] CHEN X X, LIU C, LI Q B, et al. Dynamic analysis and control strategies of Organic Rankine Cycle system for waste heat recovery using zeotropic mixture as working fluid[J]. Energy Conversion and Management, 2019, 192: 321-334. [7] CAI S Y, LI Q B, LIU C, et al. Evaporation of R32/R152a mixtures on the Pt surface: a molecular dynamics study[J]. International Journal of Refrigeration, 2020, 113: 156-163. doi: 10.1016/j.ijrefrig.2020.02.007 [8] 景玲玲,冯卉,郭晓林. 基加利修正案情况介绍[J]. 聚氨酯工业,2017, 32(S1): 17-18. [9] 王博,张伟,马洋博,等. 第四代制冷剂HFO-1234yf[J]. 化工新型材料,2010, 38(8): 30-32,40. doi: 10.3969/j.issn.1006-3536.2010.08.011 [10] 马一太,王派,李敏霞,等. 温室效应及第四代制冷工质[J]. 制冷技术,2017, 37(5): 8-13. doi: 10.3969/j.issn.2095-4468.2017.05.002 [11] HU J Y, LIU C, LIU L, et al. Thermal energy storage of R1234yf, R1234ze, R134a and R32/MOF-74 nanofluids: a molecular simulation study[J]. Materials, 2018, 11(7): 1164. doi: 10.3390/ma11071164 [12] HU J Y, LIU C, LI Q B, et al. Molecular simulation of thermal energy storage of mixed CO2/IRMOF-1 nanoparticle nanofluid[J]. International Journal of Heat and Mass Transfer, 2018, 125: 1345-1348. doi: 10.1016/j.ijheatmasstransfer.2018.04.162 [13] SUMIDA K, ROGOW D L, MASON J A, et al. Carbon dioxide capture in metal-organic frameworks[J]. Chemical Reviews, 2012, 112(2): 724-781. doi: 10.1021/cr2003272 [14] BLOCH E D, HUDSON M R, MASON J A, et al. Reversible CO binding enables tunable CO/H2 and CO/N2 separations in metal-organic frameworks with exposed divalent metal cations[J]. Journal of the American Chemical Society, 2014, 136(30): 10752-10761. doi: 10.1021/ja505318p [15] MCGRAIL B P, THALLAPALLY P K, BLANCHARD J, et al. Metal-organic heat carrier nanofluids[J]. Nano Energy, 2013, 2(5): 845-855. doi: 10.1016/j.nanoen.2013.02.007 [16] NIST. NIST standard reference database[EB/OL].(2018-09-18)[2021-04-10]. https://www.nist.gov/srd. [17] FRENKEL D, SMIT B. Understanding molecular simulation: from algorithms to applications[M]. 2nd ed. San Diego: Academic Press, 2002: 66. [18] PLIMPTON S. Fast parallel algorithms for short-range molecular dynamics[J]. Journal of Computational Physics, 1995, 117(1): 1-19. doi: 10.1006/jcph.1995.1039 [19] RAPPE A K, CASEWIT C J, COLWELL K S, et al. UFF, a full periodic table force field for molecular mechanics and molecular dynamics simulations[J]. Journal of the American Chemical Society, 1992, 114(25): 10024-10035. doi: 10.1021/ja00051a040 [20] CAI S Y, WU C, LI X X, et al. Effects of lubricant on evaporation and boiling processes of R1234ze(E): a molecular dynamics study[J]. Applied Thermal Engineering, 2021, 193: 117009. doi: 10.1016/j.applthermaleng.2021.117009 [21] LI Q B, XIAO Y T, SHI X Y, et al. Rapid evaporation of water on graphene/graphene-oxide: a molecular dynamics study[J]. Nanomaterials, 2017, 7(9): 265. doi: 10.3390/nano7090265 [22] LI Q B, WANG M, LIANG Y P, et al. Molecular dynamics simulations of aggregation of copper nanoparticles with different heating rates[J]. Physica E:Low-dimensional Systems and Nanostructures, 2017, 90: 137-142. doi: 10.1016/j.physe.2017.03.024 [23] HU J Y, LIU C, LI Q B, et al. Thermal energy storage of R1234yf/MOF-5 and R1234ze(Z)/MOF-5 nanofluids: a molecular simulation study[J]. Energy Procedia, 2019, 158: 4604-4610. doi: 10.1016/j.egypro.2019.01.870 [24] WANG S K, ZHANG L, LIU C, et al. Techno-economic-environmental evaluation of a combined cooling heating and power system for gas turbine waste heat recovery[J]. Energy, 2021, 231: 120956. doi: 10.1016/j.energy.2021.120956 [25] BERENDSEN H J C, POSTMA J P M, VAN GUNSTEREN W F, et al. Molecular dynamics with coupling to an external bath[J]. The Journal of Chemical Physics, 1984, 81(8): 3684-3690. doi: 10.1063/1.448118 [26] LEI G P, LI Q B, LIU H T, et al. Selective adsorption of CO2 by Hex-star phosphorene from natural gas: combining molecular simulation and real adsorbed solution theory[J]. Chemical Engineering Science, 2021, 231: 116283. doi: 10.1016/j.ces.2020.116283 [27] 李期斌,蔡守银,刘朝. R1234yf,R1234ze(z),R32及其混合工质在Co-MOF-74中吸附储能的分子模拟[J]. 科学通报,2020, 65(7): 633-640. -
图(6) / 表(1)
计量
- 文章访问数: 952
- HTML全文浏览量: 156
- PDF下载量: 49
- 被引次数: 0
