溴化锂溶液中添加活性炭颗粒对制冷机出力的影响

为改善吸收式制冷机的性能,基于活性炭的高吸附性,研究在溴化锂水溶液添加适量活性炭颗粒形成的悬浮液的传热传质性能,分析活性炭/溴化锂悬浮液替代溴化锂水溶液作为吸收剂的可行性。研究表明,悬浮液的粘度随活性炭浓度线性增长,以悬浮液作为吸收剂的制冷机的出力随透湿系数、悬浮液吸附平衡常数及换热表面积呈近似线性增长关系,并且,以活性炭/溴化锂悬浮液作吸收剂的制冷机出力较以纯溴化锂溶液作吸收剂的制冷机出力大。     

单效溴化锂吸收式制冷循环吸收特性与工况关系的研究

以单效溴化锂吸收式制冷机为研究对象,对溴化锂水溶液的热力性质参数进行了计算机模拟。通过模拟计算,得到了求解溴化锂水溶液热力参数的较为精确的计算方法。溴化锂吸收式制冷机是以水为制冷剂,溴化锂为吸收剂,通过消耗热能来实现制冷目的的。通过对单效循环的仿真模拟计算,实现了对机组在不同工作工况下的性能预测。为进一步利用数字和模拟手段深入研究溴化锂吸收式制冷机组奠定了良好的基础。     

吸收式制冷循环特性的稳态模拟

对溴化锂水溶液的热力性质进行模拟,得到较为精确的确定溴化锂水溶液热力参数的计算方法,为溴化锂吸收式制冷循环系统的模拟奠定基础。编制吸收式制冷机组循环模拟程序,对溴化锂吸收式制冷循环的单效及双效并联进行模拟,通过对比试验数据与模拟结果,发现模拟能够取得较为理想的结果。     

某生产车间空调方案比较

对某生产车间的空调,选用电制冷机组和溴化锂吸收式制冷机组两种方案,主要从设备初投资费用、运行费用两方面进行比较,得出了采用蒸汽型溴化锂吸收式制冷机组不可行的结论。     

三热源制冷机的制冷系数的分析

推导出 q 正比于△1/T 传热情况下最大制冷率时,内可逆三热源制冷循环的制冷系数ε_m可表示为ε_m=T_L(T_H-T_0)/[TH(2T_0-T_L)-T_LT_0],而相应的最大制冷率为 R_(max)=(α/16)T_L(T_H-T_0)~2/[T_HT_0~2(T_H-T_L)]。其中,T_H,T_L 和 T_0分别为高温热源、制冷物体和环境温度,α为传热系数。所得结果不同于线性传热 q 正比于△T 情况下所得结果。     

添加剂和纳米粒子强化溴化锂水溶液／氨水吸收特性研究进展

吸收式制冷以其节能、环保等诸多优点得到了越来越广泛的应用。本文总结与分析添加剂和纳米粒子强化溴化锂水溶液及氨水吸收特性的机制和相关实验研究的发展现状。针对吸收式制冷系统中吸收器传质系数和换热系数小而导致的制冷效率低的问题,很多学者进行了添加剂和纳米粒子对吸收过程影响的实验研究,并据此采取措施增大传质传热效率。实验主要包括以下几个方面：表面张力实验、静态池吸收实验、降膜吸收实验和氨水鼓泡吸收实验。实验结果均表明添加剂和纳米粒子可以提高吸收器中溴化锂水溶液及氨水的传热传质性能。该研究对于提高吸收式制冷系统的制冷效率有很大帮助,同时为该技术在实际系统中的应用奠定基础。     

非平衡吸附特征的吸附床传热传质特性

建立椰壳活性炭-甲醇吸附式制冷系统吸附床传热传质数学模型,应用该模型进行具有非平衡吸附特性的吸附床传热传质研究,利用数值方法对数学模型进行求解,讨论了吸附床在冷却过程中吸附剂温度、吸附速率、吸附量、制冷系数以及单位质量吸附剂制冷功率与时间的关系,吸附床在加热过程中吸附剂温度、脱附速率及脱附量与时间的关系.研究结果表明:吸附床在整个吸附过程中的吸附速率存在一个峰值0.001 2 ks/s,吸附床在整个脱附过程中的脱附速率存在一个峰值0.001 7ks/s,吸附剂温度变化率在换热阶段趋于平缓,制冷系数值在吸附阶段近似呈线性增长,而单位质量吸附荆制冷功率在吸附阶段存在一个峰值35 kW/kW.     

两级双效溴化锂制冷-热泵复合循环

在热电冷联产系统中,溴化锂吸收式制冷机在制冷过程中排放了大量的废热,这些废热品味低,难以直接回收利用。在此提出了两级双效溴化锂制冷-热泵复合循环,该循环具有冷凝温度较高的特点,便于直接回收冷凝排放热。系统以背压汽轮机的背压蒸汽为热源,制冷的同时利用循环所排出的废热加热锅炉补充水至较高温度。以具有相同功效的双效溴冷机与单效溴化锂热泵联合运行作为对比循环,制冷-热泵复合循环系统省去了一台蒸发器与冷凝器,减少了两个换热温差,并且通过热力计算、能量分析和分析表明,该循环的能量利用率与效率均有很大的提高,效率比对比循环提高了45%。     

溴化锂制冷技术在尿素余热回收中的应用

简述了蒸汽单效溴化锂吸收式制冷机组的工作原理和功能,介绍了其应用于合成氨和尿素装置的工艺流程。论述TN用尿素装置的副产低压蒸汽。通过制冷机组制取冷水,用于冷却合成氨装置中的后冷器和尿素颗粒,降低了电耗。     

提高蒸汽型溴化锂吸收式制冷机制冷性能的管理方法

根据对冷水站蒸汽型溴化锂吸收式制冷机的长期管理,提出了在气密性、溴化锂溶液、冷剂水、冷水及冷却水的水质、运行、设备等方面进行优化管理的方法,它不仅保证了制冷机组的长期稳定运行,而且提高了制冷机组的制冷性能。     

Thermal Property Measurements and Enthalpy Calculation of the Lithium Bromide+Lithium Iodide+1,3-Propanediol+Water System

The lithium bromide+lithium iodide+1,3-propanediol+water [LiBr/LiI mole ratio=4 and (LiBr+LiI)/HO(CH₂)₃ OH mass ratio=4] solution is being considered as a potential working fluid for an absorption chiller. Heat capacities at four temperatures, 283.15, 298.15, 313.15, and 333.15 K, were measured in the range from 50 to 70 mass%. In addition, the differential heats of dilution at 298.15 K were measured in the range from 45.3 to 71.8 mass%. Each individual data set was correlated with a proper regression equation with a high accuracy. A new enthalpy calculation method for the working fluids containing organics was proposed. The calculation method correlated the heat capacity (at various temperatures and concentrations) and the differential heat of dilution (at ambient temperature and various concentrations). The present method was applied for the construction of enthalpy–concentration (H–T–X) diagrams with high confidence.     

溴化锂吸收式制冷机设计应注意的问题探讨

根据目前国内溴化锂吸收式制冷机的实际运转情况，针对制冷机在非标工况下运行时容易出现的问题进行分析，并提出一些设计建议及要求，包括对机组结构设计的变更以及部件的选择等。     

溴化锂机组冷却炼厂循环水的应用分析

炼厂低温余热由于温度低、热源分布广等特点,回收热能困难,回收低温余热成为我国炼油企业节能的重要途径之一.本文通过对溴化锂吸收式制冷及炼厂低温热特点的分析,提出利用低温热作为驱动溴化锂吸收式制冷机的热源的方案,并以某催化裂化装置为例,设计单效溴化锂吸收式制冷机.该制冷机设计合理,COP为0.67,产生的冷量为8.8741 x10 7kcal/h,可实现年节省2050.3万元,经济效益显著.低温余热驱动溴化锂吸收式制冷机可以完全冷却本装置产生的循环水,实现炼厂的节能减排目标,而该制冷机安全环保,应用于炼厂的低温热回收安全可靠.     

多能源综合利用型溴化锂吸收式冷温水机的开发应用

介绍一种新型的可以单独或同时利用多种能源的溴化锂吸收式冷温水机,并对其实际应用进行系统的说明。     

溴化锂吸收式制冷机中铜及其合金的腐蚀研究进展

对溴冷机换热器中常用的铜及其合金在高温,高浓度溴化锂溶液中的全面腐蚀,局部腐蚀和冷却水侧的腐蚀行为研究进行了扼要综述,并对其应用前景进行了展望。     

溴化锂溶液中苯并三氮唑对碳钢缓蚀作用研究

为降低溴冷机中碳钢的腐蚀,通过失重法和电化学方法研究了含有0.07 mol/L LiOH和150mg/L Na2MoO4的55%LiBr、60%LiBr溶液中苯并三氮唑(BTA)对碳钢的缓蚀作用.结果表明,在溴化锂溶液中添加BTA时可显著降低碳钢腐蚀;55%LiBr、60%LiBr溶液中BTA的最佳添加量为100 mg/L;55%LiBr溶液中,BTA通过与铁离子形成Fe-BTA型配合物覆盖在金属表面阻碍浸蚀性Br-吸附而起缓蚀作用;60%LiBr溶液中,BTA则与MoO42-共同作用,在碳钢表面形成MoO2、MoO3和Fe-BTA致密钝化膜减缓金属活性溶解.     

Experiments on saturated vapor pressure of aqueous lithium bromide solution at high temperatures

This work mainly focuses on the determination of the saturated vapor pressure of LiBr aqueous solution with mass fraction ranging from 43.14 to 65.26 wt% at high temperature experimentally. First, the measurement of the saturation vapor pressures is conducted in deionized water as well as in LiBr aqueous solution at a lower temperature. The experimental result has a good agreement with the literature value, which verified the reliability and accuracy of the experimental apparatus. Second, measurement of the saturated vapor pressure of LiBr aqueous solution with mass fraction ranging from 43.14 to 65.26 wt% is systematically carried out in the 156.06~257.84 °C temperature range. Based on the saturated vapor pressure data at lower temperature, a correlation for predicting the saturated vapor pressure data of the LiBr aqueous solution is obtained, which is also available for high temperature condition. Therefore, this work will be very helpful for the modeling and design of high temperature LiBr/H₂O absorption heat transformers.     

Removal of mercury(II) from aqueous solutions and chlor-alkali industry effluent by steam activated and sulphurised activated carbons prepared from bagasse pith: kinetics and equilibrium studies

The adsorption of mercury from aqueous solutions and chlor-alkali industry effluent on steam activated and sulphurised steam activated carbons prepared from bagasse pith have been studied comparatively. The uptake of mercury(II) (Hg(II)) was maximum by steam activated carbon in presence of SO(2) and H(2)S (SA-SO(2)-H(2)S-C) followed by steam activated carbon in presence of SO(2) (SA-SO(2)-C), steam activated carbon in presence of H(2)S (SA-H(2)S-C) and steam activated carbon (SA-C) at the same concentration, pH and temperature of the solution. Adsorption experiments demonstrate that the adsorption process corresponds to the pseudo-second-order kinetic model and equilibrium results correspond to the Langmuir adsorption isotherm. Kinetic parameters as a function of initial concentration, for all adsorbents were calculated. Batch studies indicated that the optimum pH range for the adsorption of Hg(II) on sulphurised carbons was between 4 and 9 and for sulphur free carbon was between 6 and 9 at 30 degrees C. The adsorptive behaviour of the activated carbons is explained on the basis of their chemical nature and porous texture. Decrease in ionic strength and increase in temperature of the solution has been found to improve the uptake of Hg(II). Synthetic and chlor-alkali industrial wastewaters were also treated by sulphurised activated carbons to demonstrate their efficiencies in removing Hg(II) from wastewaters. Some feasibility experiments have been carried out with a view to recover the adsorbed Hg(II) and regenerate the spent activated carbons using 0.2M HCl solution. The data obtained point towards viable adsorbents, which are both effective as well as economically attractive for Hg(II) removal from wastewaters.