单双效结合运行的溴化锂第一类吸收式热泵

在传统的单效和双效溴化锂第一类吸收式热泵的基础上,开发单双效结合运行的溴化锂第一类吸收式热泵机组。当用户需求热水温度较低时,机组以双效模式运行;反之,机组则以单效模式运行。克服了溴化锂第一类吸收式热泵供热系统中机组模式单一化、运行效率低的缺点,实现了一台机组两种模式运行的方案,提高了设备和资源的利用率,具有良好的节能效益和经济效益。     

溴化锂制冷机组运行数据分析及优化策略

溴化锂制冷机组作为低温热阱,在石化企业得到了广泛应用。随着工况的改变,低温热系统操作条件及溴化锂制冷机组的运行性能将偏离最优运行条件,导致制冷效率降低。针对溴化锂制冷机组运行效果不佳的情况,提取实际运行数据,通过数据分析,并结合机理模型和线性回归模型,建立溴化锂制冷机组冷水预测模型,模拟结果能正确反映溴化锂制冷机组运行工况,模拟结果与实际结果吻合较好。基于模型,获得了制冷机组不同流量所对应的最优热媒水流量及上水温度,并提出了溴化锂制冷机组的优化运行方案。通过将热媒水流量从282t/h提高至318t/h,温度从80℃提高至90℃,冷水温度可从14.65℃降低至11.7℃。降低冷水温度后,有利于降低延迟焦化吸收塔吸收剂温度,从而降低干气C_3含量,提高装置经济效益。     

直燃式溴化锂冷热水机组的研究与发展

一、概述 1.直燃式溴化锂冷热水机组的特点 溴化锂吸收式制冷机是利用不同温度下溴化锂水溶液对水蒸汽的吸收与释放来实现制冷的。显然这种循环要利用外来热源实现。现常用的热源有蒸汽、热水、燃气、燃油等,其中我们习惯于把热源为燃气、燃油的制冷机组称为直燃式机组。该种机组是在溴化锂吸收式冷热水机组的基础上开发的新机型。除了具有吸收式冷热水机组的优点外,还具有以下优点: (1)燃烧效率高,燃烧完全,燃烧产物中NOx与SOx的含量较低,减小对大气的污染。     

基于生物质斯特林溴化锂吸收式机组三联供系统能效分析

设计搭建了一套以生物质为一级燃料斯特林热电联产能源利用系统,并对系统中的双效溴化锂机组性能特性进行分析。该系统的斯特林发动机由生物质在大型燃烧炉中燃烧产生高温烟气提供驱动热量,烟气温度为600℃左右,发动机发电,换热后的烟气余热进入溴化锂机组制冷和供热,实现冷热电三联供。系统采用程序监测并采集运行参数,基于200℃左右烟气,计算分析比较单、双效及两级双效溴化锂机组效率和运行特性,最终确立使用两级双效溴化锂机组系统方案。     

溴化锂吸收式供热机组在供热行业中的应用研究

通过对溴化锂吸收式换热机组改造项目运行数据进行统计分析,计算出其节约一次热网平均流量,进而核算实际经济效益,展望该项目未来在供热行业的应用前景。     

热水型双效压缩吸收式制冷循环热力分析

通过对太原地区中央空调运行费用的调查,得出热水型溴化锂机组运行费用相对较小。针对集中供热热水用于溴化锂吸收式制冷时的温度不匹配问题,提出在双效并联循环中增加一个加压装置的办法,通过补偿一部分电能以扩大双效循环对热源温度的适用范围,从而使得双效溴化锂吸收式制冷可以使用集中供热一次热源作为驱动能源。     

二泵系统新流程溴化锂制冷机的研制

一、概述”近年来溴化锂吸收式制冷机在我国取得了迅速发展，这是基于溴化锂吸收式制冷机是一种以低品位热能为动力的制冷设备，特别在我国目前电力供应比较紧张的情况下，具有节电和节能的显著效果，同时为了保护地球臭氧层，蒙特利尔协议书对氟里昂的应用作了限制，而溴化锂对环境无公害，不会破坏大气臭氧层，因此，溴化锂吸收式制冷机受到特别重视。但是纵观我国溴化锂吸收式制冷机的现状，大多采用传统的三泵系统，并联流程，不仅机组装机功率偏大，而且在流程设计上存在着容易产生“结晶”现象的隐患，为此，我们在消化吸收国内外先进…     

内燃机耦合溴化锂机组调试关键技术分析

针对某冷热电三联供分布式能源站系统,对燃气内燃机的缸套水、中冷水及润滑油系统冷却模块进行了系统的介绍与分析,内燃机耦合吸收式制冷机组调试过程进行研究,进一步地针对余热利用设备烟气热水型溴化锂机组调试过程中发现的问题进行分析,并提出解决办法,最后总结并出该类型内燃机耦合溴化锂机组调试过程的关键步骤,为同类型机组初期调试及商业运行提供经验。     

溴化锂制冷机组节能综合效果评价

通过溴化锂和往复式制冷机组的能耗比较,在机组制冷容量与空调最大冷负荷相匹配的条件下,两种机组能耗无明显差异,但溴化锂机组节电显著。只要合理利用废汽和余汽,溴化锂机组是目前制冷设备选型中考虑节能因素的首选机型。     

溴化锂制冷机组节能综合效果评价

通过溴化锂和往复式制冷机组的能耗比较,在机组制冷容量与空调最大冷负荷相匹配的条件下,两种机组能耗无明显差异,但溴化锂机组节电显著。只要合理利用废汽和余汽,溴化锂机组是目前制冷设备选型中考虑了能因素的首选机型。     

Thermodynamic performances of [mmim]DMP/Methanol absorption refrigeration

In order to study the theoretical cycle characteristic of [mmim]DMP(1-methyl-3-methylimidazolium dimethylphosphate)/methanol absorption refrigeration,the modified UNIFAC group contribution model and the Wilson model are established through correlating the experimental vapor pressure data of [mmim]DMP/methanol at T=280～370K and methanol mole fraction x=0.529～0.965.Thermodynamic performances of absorption refrigeration utilizing [mmim]DMP/methanol,LiBr/H2O and H2O/NH3 are investigated and compared with each other under the same operating conditions.From the results,some conclusions are obtained as follows:1)the circulation ratio of the [mmim]DMP /methanol absorption refrigeration is higher than that of the LiBr/H2O absorption refrigeration,but still can be acceptable and tolerable.2)The COP of the [mmim]DMP/methanol absorption refrigeration is smaller than that of the LiBr/H2O absorption refrigeration,while it is higher than that of the H2O/NH3 absorption refrigeration under most operating conditions.3)The[mmim]DMP/methanol absorption refrigeration are still available with high COP when the heat source temperature is too high to drive LiBr/H2O absorption refrigeration.     

氨水吸收式制冷夹点分析法

氨水吸收式制冷需要消耗很大的公用工程,其性能系数(COP)不是很高,引入夹点分析法分析氨水吸收式制冷系统,该方法能够确定可回收的系统最大内部循环热,优化后的系统性能系数为0.623,比优化前的系统性能系数高11.58%。该方法对氨水吸收式制冷设计具有一定的指导意义。     

溴化锂吸收式制冷技术研究进展

回顾了近十年来有关溴化锂吸收式制冷技术的发展及主要研究成果。H₂O/LiBr作为一种广泛应用的吸收式制冷工质对,具有优良的热力学性能与环保特性,但存在结晶、腐蚀和循环性能低等问题。文章简述了醇类、盐混合物、离子液体及纳米颗粒等添加剂对H₂O/LiBr溶液传热传质、防结晶及防腐蚀等性能的提升;介绍了关键部件吸收器和发生器的理论及实验研究现状;回顾了吸收式制冷系统循环优化的研究成果。通过归纳分析,总结溴化锂吸收式制冷技术存在的一些问题及未来发展趋势,为后续的研究提供参考。     

升膜理论在氨水吸收式制冷循环中的应用

由于可以利用低品位热源制冷,氨水吸收式制冷系统得到了广泛的应用。氨水系统的精馏器要求很高的安装精度,限制了其应用范围。为了开发新型制冷器,将升膜理论应用到氨水吸收式制冷系统中,用一个冷凝发生器来实现精馏塔的作用。研究结果表明,本循环的热力系数比较高,这一成果可广泛应用于各种车、船等的制冷系统设计中。     

Thermodynamic performance analysis of gas-fired air-cooled adiabatic absorption refrigeration systems

In China, the application of small size gas-fired air-cooled absorption refrigeration systems as an alternative for electric compression air conditioning systems has shown broad prospects due to occurrence of electricity peak demand in Chinese big cities and lack of water resources. However, for conventional air-cooled absorption refrigeration systems, it is difficult to enhance the heat and mass transfer process in the falling film absorber, and may cause problems, for example, remarkable increase of pressure, temperature and concentration in the generators, risk of crystallization, acceleration of corrosion, degradation of performance, and so on. This paper presents a gas-fired air-cooled adiabatic absorption refrigeration system using lithium bromide–water solutions as its working fluid, which is designed with a cooling capacity of 16 kW under standard conditions. The system has two new features of waste heat recovery of condensed water from generator and an adiabatic absorber with an air cooler. Performance simulation and characteristic analysis are crucial for the optimal control and reliability of operation in extremely hot climates. A methodology is presented to simulate thermodynamic performance of the system. The influences of outdoor air temperature on operation performances of the system are investigated.     

Computer-aided conceptual thermodynamic design of a two-stage dual fluid absorption cycle for solar refrigeration

This communication presents thermodynamic assessment of a two-stage dual fluid absorption refrigeration system using H₂O---LiBr and NH₃---H₂O as working fluids at the first and second stage, respectively. Both stages are assumed to be operated with hot water available from separate solar collectors. In the cascading of two-stage absorption systems, the evaporator of the first stage produces cooling water which is circulated in the absorber of the second stage. It is found that two-stage systems can be used for the production of very low temperatures using moderate generator temperatures at the first stage. The effects of generator temperature, absorber temperature and condenser temperature on the coefficient of performance, minimum evaporator temperature and effective refrigeration produced are also presented.     

Thermal modelling and parametric study of two stage absorption refrigeration and air-conditioning systems

This paper presents a thoermodynamic assessment of two stage absorption refrigeration and air-conditioning systems. Two working fluids, namely water-LiBr and NH₃-H₂O as refrigerant-absorbent combinations have been considered for the production of different cooling temperatures. Both the systems are assumed to be operated with hot water available from solar collectors. Thermal modelling and a parametric study of a two stage absorption system, based on thermodynamic analysis aided by computer, have been carried out in detail. It is found that the cascading of two stage absorption systems (in which the first stage evaporator produces cooling water to be circulated in the absorber of the second stage) can be easily operated to produce much lower temperatures suitable for refrigeration and air-conditioning applications. The COP of a two stage absorption system is lower than that of a single stage; however, the second stage can be operated with lower generator temperatures than the first stage. However, there is an advantage for a two stage system because of the slow fall-off in COP at higher generator temperatures.     

Exergy analysis of double effect vapor absorption refrigeration system

Energy and exergy analyses previously performed by the authors for a single effect absorption refrigeration system have been extended to double effect vapor absorption refrigeration system with the expectation of reducing energy supply as well as an interest in the diversification of the motive power employed by HVAC technologies. The total exergy destruction in the system as a percentage of the exergy input from a generator heating water over a range of operating temperatures is examined for a system operating on LiBr–H₂O solution. The exergy destruction in each component, the coefficient of performance (COP) and the exergetic COP of the system are determined. It is shown that exergy destructions occur significantly in generators, absorbers, evaporator2 and heat exchangers while the exergy destructions in condenser1, evaporator1, throttling valves, and expansion valves are relatively smaller within the range of 1–5%. The results further indicate that with an increase in the generator1 temperature the COP and ECOP increase, but there is a significant reduction in total exergy destruction of the system for the same. On the other hand, the COP and ECOP decrease with an increase in the absorber1 temperature while the total exergy destruction of the system increases significantly with a small increase in the absorber1 temperature. The results show that the exergy method can be used as an effective criterion in designing an irreversible double effect absorption refrigeration system and may be a good tool for the determination of the optimum working conditions of such systems. Copyright © 2007 John Wiley & Sons, Ltd.     

新型CH3OH-LiBr-ZnCl2吸收-喷射制冷系统变工况分析

吸收－喷射制冷循环系统改变了单效吸收式制冷系统热力参数间相互制约关系，具有参数调节范围宽的特点。对变工况条件下温度、压力等参数对性能的影响进行了研究。     

吸收式制冷循环利用低品位热能的研究现状和发展趋势

介绍吸收式制冷循环利用低品位热能的研究现状和发展趋势。阐述吸收式制冷系统对太阳能、工业余热、生物质能和地热能四种能源的利用情况,并主要从低品位热能的选择、吸收式制冷循环系统的优化和吸收器的优化三方面分析该系统存在的问题和发展趋势。