低环境温度空气源热泵（冷水）机组新版国家标准解析

介绍GB/T25127.1《低环境温度空气源热泵(冷水)机组第1部分:工业或商业用及类似用途的热泵(冷水)机组》和GB/T25127.2《低环境温度空气源热泵(冷水)机组第2部分:户用及类似用途的热泵(冷水)机组》修订的背景和解决的重点问题,解读新版标准主要内容,包括范围、机组型式、试验工况及允差、性能系数、技术要求、噪声试验方法、水侧压力损失、APF计算和试验方法、融霜试验方法、制热性能试验方法等内容,为相关人员正确理解标准条款和评价产品性能提供技术指导。     

低温空气源热泵（冷水）机组名义工况的确定研究

对低环境温度空气源热泵(冷水)机组(简称低温热泵)标准中的名义制热工况确定问题进行了研究.通过对我国寒冷地区典型城市供热季节的室外干球温度及其对应湿球温度的分布进行统计分析,确定出低温热泵空气侧的名义制热工况条件为-12℃/-13.5℃;通过对典型房间分别采用风机盘管和辐射地板进行供热时,保证室内舒适性要求的空调末端出水温度的研究,给出了水侧的名义制热工况为回水温度38℃.上述结论可为商用和户用低环境温度空气源热泵(冷水)机组的标准制定提供参考.     

铁路工程低温空气源热泵运行实测与优化分析

铁路沿线房屋常常远离城市且具有“点多线长”的特点,当铁路客站不具备接入市政供暖和燃气时,空气源热泵因取热方便、能效比高等优势在铁路工程中应用广泛。为探究低温空气源热泵在铁路工程的应用效果及性能,对低温空气源热泵在铁路工程应用的3个工程进行了实测,重点分析了低温空气源热泵机组在不同地区使用的容量修正问题。研究结果表明：由于机组的制热性能受室外环境影响大,为提高低温空气源热泵的制热性能,机组选型时温度修正系数需考虑供暖季的热负荷频率分布和辅助热源措施以防止设备容量过大。此外,由于重霜区集中在温度不太低,湿度较高的区域,在严寒、寒冷地区低温空气源热泵的“无霜除霜”的现象较为严重,其融霜修正系数取值建议在0.88～0.95范围内。再次,铁路房屋供暖末端形式受热泵机组的供水温度影响,建议以散热器为末端供暖系统采用CO₂低温空气源热泵机组,以辐射地板和风机盘管采用常规制冷剂空气源热泵机组即可满足要求。     

选择不同负荷组合对测试多联机IPLV的影响

指出综合性能系数（IPLV）与部分负荷Q2（75%±10%）,Q3（50%±10%）和Q4（25%±10%）之间的关系,并用实例说明当采用不同的部分负荷组合进行IPLV测试时,有时会得到不同的测试结果.     

采用定速压缩机的低环境温度空气源热泵(冷水)机组季节能效评价分析及试验研究

产品标准GB/T 25127.1—2020《低环境温度空气源热泵(冷水)机组第1部分:工业或商业用及类似用途的热泵(冷水)机组》于2021年4月1日实施,对该类产品的性能评价方法由综合部分负荷性能系数(IPLV)转变为季节能效(HSPF及SEER)评价。如何适应新版标准的评价方法,本文从季节能效评价的基本思路进行理论分析,对季节能效试验的主要优化方向进行研究,并通过试验进行验证。结果表明,改进后的测试策略使机组HSPF及SEER分别提升4.9%和3.3%。     

低环境温度空气源多联式热泵（空调）机组制热性能的评价方法

介绍GB/T 25857—2010《低环境温度空气源多联式热泵（空调）机组》中关于制热综合性能系数（IPLV（H））算法的制定思路,并给出其＂部分负荷系数曲线＂的构建方法,供GB/T 25857—2010使用者参考。     

空气源热泵名义制热量损失系数模型研究

为正确评价空气源热泵机组在结除霜过程的运行性能,探索其在冬季结霜工况下的运行性能,本文提出以"名义制热量损失系数"作为评价空气源热泵结除霜损失的重要参数,并基于大量实测数据,采用广义人工神经网络的预测方法,建立空气源热泵名义制热量损失系数的预测模型。结果表明:建立的预测模型相关系数r 0. 9,期望偏差百分数(EEP)小于6. 5%,模型学习训练效果及通用能力表现良好,该模型可用于预测空气源热泵机组结除霜过程的制热性能,预测结果可作为探寻不同结霜工况下最佳除霜控制点的重要依据。     

多联式空调（热泵）机组能效的理论极限

分析多联式空调（热泵）机组的换热器热平衡,推导其综合性能系数极限值的计算方法,并用该计算方法计算得知,在GB/T18837—2002规定的工况下,多联机IPLV（C）的极限值为18.19,IPLV（H）的极限值为10.35。指出若不能通过改进盘管设计、增大换热面积、提高盘管换热效率的方法使满负荷下的室内盘管空气温差和室外盘管空气温差分别低于8℃和10℃,多联机的综合性能系数将很难突破以上极限。     

过冷段翅片管换热器的试验研究

对过冷段翅片管换热器对空气源热泵冷热水机组系统性能的影响进行试验研究。过冷段翅片管换热器通过横向导热和强制对流换热可增大制冷剂液体过冷度，制热工况下，可使系统性能系数COP提高约19％，并有效降低翅片表面结霜。     

《GB/T 18837-2002多联式空调(热泵)机组》标准中IPLV问题分析探讨

中针对多联式空调(热泵)机组部分负荷能耗效能的评价参数指标IPLV的标定计算作了明确的规定,但是针对多联式空调系统有别于单台冷水机组运行特性和能效的特性,决定TIPLV的标定计算忽略了室内机作为机组系统的一部分而对系统负荷率及能效变化所构成的影响.提出多联式空调系统IPLV的计算公式理应在综合分析研究机组运行工况、系统开机率、室内机负荷均匀度、部分负荷率及对应负荷率下机组的能效比这些影响因素而综合定义给出.     

La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2合金的储氢性能研究

针对两种新型稀土型储氢合金La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2的储氢特性进行研究分析。实验表明,相同温度下,La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2合金的PCT曲线基本重合,且都具有优良的吸氢动力学性能;相比之下,后者的滞后系数要小于前者,吸氢量较大,吸氢速率也较快,故其储氢性能较优。300次吸放氢循环实验结果表明,La0.5Y0.5Ni4.8Al0.2合金的吸氢动力学性能虽然略有下降,但抗粉化性能较好。     

Dy0.6Tb0.3Pr0.1(Fe0.95Mn0.05)x取向晶体的结构与磁致伸缩

采用Ｃｚｏｃｈｒａｌｓｋｉ方法生长了Ｄｙ０．６Ｔｂ０．３Ｐｒ０．１（Ｆｅ０．９５Ｍｎ０．０５）ｘ（１．８５≤ｘ≤１．９５）取向合金。所有合金主相为立方Ｌａｖｅｓ相结构,择优取向不完整择优取向的方向与Ｘ的大小有关。研究了沿着这些样品的生长方向的磁致伸缩性能以及磁致伸缩性能与压力之间的关系。     

Thermal Stability of Amorphous Hydride Mg_(50)Ni_(50)H_(54) and Mg_(30)Ni_(70)H_(45)

The thermal stability of amorphous ternary hydrides Mg_(50)Ni_(50)H_(54) and Mg_(30)Ni_(70)H_(45) and their corre-sponding amorphous binary alloys Mg_(50)Ni_(50) and Mg_(30)Ni_(70) were studied with X-ray diffraction(XRD) and differential scanning calorimetry(DSC). Samples of the amorphous alloys were preparedby mechanical alloying and the amorphous hydrides were obtained by charging the alloys with gas-eous hydrogen at 3.0 MPa and 423 K. It was found that the amorphous hydrides released most oftheir hydrogen before the crystallization of the essentially hydrogen depleted amorphous alloy. Thecrystallization temperature of amorphous Mg_(50)Ni_(50)H_(54) elevated and that of amorphousMg_(30)Ni_(70)H_(45) did not change in relation to the original binary amorphous alloy. This is very excep-tional for amorphous hydrides. The reason for the effects of hydrogen absorption/desorption on thecrystallization of amorphous alloys was discussed.     

Zr65Al7.5Ni10Cu15Co2.5合金的玻璃转变温度

根据Ｚｒ６５Ａｌ７。５Ｎｉ１０Ｃｕ１５Ｃｏ２。５合金的纳米晶，晶体，液体和玻璃比热的测量结果，研究了合金的玻璃转变温度与全金的热力学函数，动力学参数以及加热速度的关系。结果表明，非晶态合金玻璃转变所需转变激活能很小，玻璃转变温度实际上是由于加热速度引起的不同状态的玻璃与液体的热力学平衡温度。     

Acousto-optic interaction in alpha-BaB(2)O(4)and Li(2)B(4)O(7) crystals

Experimental studies and analysis of acousto-optic diffraction in alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals are given. Ultrasonic wave velocity, elastic compliance and stiffness coefficients, and piezo-optic and photoelastic coefficients of alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals are determined. The acousto-optic figure of merit has been estimated for different possible geometries of acousto-optic interaction. It is shown that the acousto-optic figures of merit for alpha-BaB(2)O(4) crystals reach the value M(2)=(270 +/- 70) x 10(-15) s(3)/kg for the case of interaction with the slowest ultrasonic wave. The directions of propagation and polarization of those acoustic waves are obtained on the basis of construction of acoustic slowness surfaces. The acousto-optic diffraction is experimentally studied for alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals.     

Nanomechanical characterization of one-step combustion-synthesized Al(4)B(2)O(9) and Al(18)B(4)O(33) nanowires

Two kinds of aluminum borate nanowires, Al(4)B(2)O(9) and Al(18)B(4)O(33), were successfully synthesized by a one-step combustion method through control of the Al:B atomic ratio and synthesis temperature. Both nanowires are single crystalline but have distinguishing growth habits. Nanoindentation tests were performed directly on individual nanowires to reveal their mechanical properties. A 70% reduction in elastic modulus was found in Al(18)B(4)O(33) nanowires compared with their bulk counterpart. Al(18)B(4)O(33) nanowires exhibited higher hardness and elastic modulus than Al(4)B(2)O(9) nanowires.     

Natural Passivity of Amorphous Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 Alloys

The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger electron (including Ar+ ion depth profiling) spectroscopy (AES). The following aspects have been investigated: (1) chemical states of the elements in the films. binding energies and the chemical shifts measured by XPSf (2) structure and composition of the films fand (3) thickness of the passive films determined by AES depth profiling and XPS analysis.     

Plasma surface treatments of poly(l-lactic acid) (PLLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV)

The surfaces of poly(l-lactic acid) (PLLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) were modified by oxygen and nitrogen plasma treatments. The physical and chemical surface characteristics were evaluated by contact angle tests, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The plasma treatments caused an increase in both contact angle and roughening, altered the surface morphology, inserted polar groups, and, consequently, enhanced the hydrophilicity for both PLLA and PHBV polymers.     

An SANS Study of Decomposition Kinetics in Amorphous Cu_(12.5)Ni_(10)Zr_(41)Ti_(14)Be_(22.5)

Phase decomposition in amorphous Cu12.5Ni10Zr411Ti14Be22.5 alloy as annealed in the super-cooled liquid range was studied by applying small angle neutron scattering (SANS). As annealed between 600 K and 700 K, the alloy was observed to decompose into two new amorphous phases,with the second phase precipitates embedded in the matrix of the first. Long time annealing of the alloy results in crystallization in addition to evolution of the decomposed microstructure.The kinetic diagram of the decomposition and crystallization for this alloy is given. The second phase precipitates have several nanometers in size and occupy a quite low volume fraction. The decomposition of the supercooled liquid in overall temperature range exhibits the features of spinodal reaction.