舰船真空海水淡化装置热力分析

针对目前舰船上广泛使用的真空式海水淡化装置进行热力分析，建立起海水淡化装置的数学模型，以50t／d真空式海水淡化装置为例，通过对不同蒸发温度和不同工作蒸汽压力进行模拟计算，得到海水淡化装置的产水量、工作蒸汽耗量及冷却水流量随蒸发温度和工作蒸汽压力的变化规律，所得结论与装置的实验及实际运行情况有很好的一致性，证明所建立的数学模型是合适的，所得结论可以指导装置的使用管理及海水淡化装置的设计。     

真空蒸馏海水淡化的热力分析

海水淡化技术在不断地发展,从传统的蒸馏法到目前的膜处理.真空蒸馏处理技术(VDT)是在烘干处理技术基础上的发展,应用在船舶上,利用船舶的废热来淡化海水的一项技术,分析了原理,并对其进行了热力分析,建立了数学模型,并对100 t/d的装置进行了模拟计算,得到产水量随着工作蒸汽温度和蒸发温度之间的变化规律.真空蒸馏海水淡化具有节能、环保,利用效率高等优越性,前景非常明朗.     

低温多效蒸馏海水淡化与热力发电厂联产方式选择

低温多效蒸馏海水淡化是现有热法海水淡化中能耗最低的工艺。从热力发电厂供热方式及低温多效蒸馏供热需求考虑,提出了三种可行的联产工艺方式,包括"汽机抽汽—蒸汽压缩—低温蒸馏"、"汽机抽汽-蒸汽发生-低温蒸馏"和"汽机乏汽-低温蒸馏"。然后以300MW级发电机组与单机12500t/d低温多效蒸馏装置配合为例,参考热电联产供热-发电热耗分配方法,对三种联产方式进行了能耗分析,反映了不同联产方式时淡化成本的区别。     

热管式低温多效海水淡化系统及工艺流程

本热管式低温多效海水淡化系统,包括多组热管式多效蒸发器、蒸汽喷射器TVC、冷却器、气水释放装置、汽水分离器、水环典空泵、原水泵、淡泵、汽轮机中压缸、汽轮机低压缸等,还包括热管式多效蒸发器问的蒸汽、产品水及浓盐水的分布。本系统还公丌了热管式低温效海水淡化系统的工艺流程：汽轮机中压缸抽汽通过蒸汽喷射器TVC引射冷却器中的循环蒸汽及汽轮机低压缸排汽,使循环蒸汽及汽轮机低压缸排汽变为较高品质的蒸汽进入热管式蒸发器,蒸汽在吸热端通过热管冷凝放热,将热量传递到另一端加热雾化的海水;海水经过加热汽化后作为下一效蒸发器的热源,加热下一级的海水,同时被冷却产生淡水;最后一级蒸汽进入冷却器,蒸汽被海水冷却的海水,同时被加热,产生的不凝气体通过气水释放装置排出;水环真空泵抽出多效蒸发器的不凝气体,使系统在负压状态下运行;浓水通过管道排至系统外,淡水通过透过液泵送至淡水箱。     

热泵型海水淡化系统节能可行性的理论探索

分析了多效蒸馏海水淡化技术的运行原理以及热泵运行工况与该系统的适应性,将热泵系统与多效蒸馏海水淡化系统进行结合,组成热泵型海水淡化系统,从而实现热量的回收循环利用,达到节能降耗的目的,并通过理论热力计算初步验证探索该理论方向的可行性。     

低温多效热管式蒸发器

本低温多效热管式蒸发器,其低温多效热管式蒸发器,包括壳体,所述壳体内设置有多根间隔排列的热管,所述多根间隔排列的热管上方设置有喷淋系统,所述喷淋系统与海水进口连接,所述壳体上设置有至少一个蒸汽进口、至少一个浓水口、至少一个抽真空口和至少一个蒸汽出口。可以有效利用热管的特性,提高传热效率,从而提高海水淡化系统的能源利用率。     

回转吸收再压缩式汽车空调系统的性能分析

本文建立回转吸收再压缩汽车空调系统的分析模型，对采用Ｈ２Ｏ／ＬｉＢｒ工质材的回转吸收再压缩系数进行了热力分析，分析结果表明，其制冷系统接近现在使用的蒸汽压缩式系统，再加在该系统用水做制冷剂对环境绝对安全，因此它是一种比较理想的汽车空调系统。     

蒸气压缩式制冷循环制冷剂的热力优值评价

虽然热电制冷和蒸气压缩式制冷产生制冷效应的方式不同,但是热电材料在热电制冷中的作用相当于蒸气压缩式制冷循环中的制冷剂。在热电制冷中,将在研究其制冷系数的过程中导出的"热电优值"作为评价热电材料性能的指标。类似地,本文通过建立蒸气压缩式制冷循环的制冷系数的解析式,导出制冷剂的"热力优值",将其作为制冷剂热力性能的评价指标,并计算常用制冷剂的"热力优值"。     

太阳能蒸馏式海水淡化技术蒸馏器三大缺陷各自解决技术的结合研究

针对太阳能蒸馏式海水淡化技术蒸馏器三大缺陷的,介绍了已有的解决方法：叙述了与传统海水淡化技术结合的太阳能海水淡化系统。     

基于FLUENT的热力蒸汽压缩机流动模拟

热力蒸汽压缩机(TVC)具有结构简单、投资少、易于维护等优点,在水处理领域有着广泛应用。使用流体模拟软件FLUENT对TVC进行了数值模拟,验证了其内部流场与激波特性,分析了运行参数对热力蒸汽压缩机内部流动状态的影响。这对于TVC性能研究及优化设计具有重大意义。     

Thermal seawater desalination based on self-heat recuperation

Recently a novel self-heat recuperation (SHR) technology has been developed for energy saving. In the SHR process, both sensible heat and latent heat are circulated by compression work. Energy consumption is thereby drastically reduced. Using this technology, a new thermal desalination process is developed for reducing energy consumption. The energy required for this SHR-based process is explained by process simulation. It requires ~1/4 the energy of the conventional multi-stage flash desalination process, which is the most widely used thermal desalination. Thus, the proposed thermal desalination process is promising for application in industrial plants.     

Energy,exergy, environment and economic analyses and optimization of two-stage absorption–compression combined refrigeration system

In the present paper, integration of a two-stage absorption refrigeration system with a compression refrigeration system is proposed for utilizing low-temperature heat and reducing electric energy consumption. The proposed system is analyzed and compared with vapor compression system from the viewpoint of energy, exergy, environment and economics. The proposed system reduces the electricity consumption by 89.3% and CO₂ emission from 112.6 to 12.1 ton/year. The size and cost of the system are determined by designing the heat exchangers. The optimization is also performed with the objective of minimizing the annual cost of plant operation which includes fuel exergy cost, initial investment and maintenance cost and environmental damage cost due to CO₂ emission. The annual cost of its operation is 21.6% less than equivalent vapor compression refrigeration system which is further reduced by 18.2% through system optimization.     

热管/蒸气压缩复合空调原理及其在高发热量空间的应用效果分析

移动通讯基站与网络数据机房等高发热量空间由于需要全年供冷,空调能耗很高。热管/蒸气压缩复合制冷技术是一种将分离式热管和蒸气压缩式制冷有机融合,实现两者优势互补的高效冷却技术。本文阐述热管/蒸气压缩复合制冷技术的工作原理与节能机制,并将开发的热管/蒸气压缩空调机组在全国南北多个基站中进行长期试点应用,实测结果表明,机组运行稳定、室内温度控制良好,在同等条件下,比常规基站空调节能30%~45%。该机组的设计原理与应用结果为各种类型热管/蒸气压缩复合制冷机组的研发和应用奠定基础。     

罗茨水蒸气压缩机性能实验研究

压缩机是蒸气压缩蒸发系统的核心设备,会显著影响系统的能耗和运行稳定性.本文搭建了基于罗茨压缩机驱动的蒸气压缩蒸发实验台,蒸发温度为80～100℃,蒸发压力为46.60～101.64 kPa,压缩机压升为17.86～36.03 kPa,蒸发量为125.72～424.85 kg/h,实验研究了吸气流量、压缩比功、容积效率和...     

Performance analysis of a combined vapor compression cycle and ejector cycle for refrigeration cogeneration

A hybrid vapor compression refrigeration (HVCR) system, which combines a vapor compression refrigeration (VCR) system and an ejector refrigeration (ER) system, was developed. The waste heat energy from the gas cooler in the VCR system is applied as driven source towards ER system.Thermodynamic investigations on the performance of the HVCR system, using CO₂ as a refrigerant, are performed with energetic and exergetic methods, and the comparative analyses with the VCR system are conducted. Comprehensive effects of key operating parameters on the system performance are also studied. The results indicate that for the same cooling capacity, the coefficient of performance (COP) of the HVCR system shows 25% higher COP and the total mechanical power consumption is reduced by 20% than that of conventional VCR system, respectively. The performance characteristics of the proposed cycle show its application potential in cooling and air-conditioning.     

复叠式与二级压缩式热泵冷冻干燥系统循环特性比较

为了降低干燥过程的能耗,提高冷冻干燥过程的经济性,故以R600a/R290和R90为工质,分别构建了复叠式循环和二级压缩式循环的热泵冷冻干燥系统.对2种热泵干燥系统的构建方法和循环性能进行了分析和计算,并讨论了中间温度、加热温度和冷阱温度变化对系统循环特性的影响.计算结果表明,复叠式热泵循环和二级压缩式热泵循环均可用于冷冻干燥系统;在常规的冷冻干燥条件下,系统中采用复叠式热泵循环较适宜.     

Semi-empirical modeling and analysis of oil flooded R410A scroll compressors with liquid injection for use in vapor compression systems

Oil flooding is a technique that can be utilized in compression systems to achieve near-isothermal compression. This can lead to a boost in system efficiency and a reduction in compressor power consumption. In this paper a semi-empirical model for oil flooded compressors using liquid injection was developed. The model is validated with experimental data and integrated into a thermodynamic model of a vapor compression system with oil flooding and regeneration. The performance of the heat pump system is predicted and the semi-empirical model is used to identify and estimate the magnitude of the irreversibilities during the compression process. A method for generalizing the model for different working fluids is also presented. Using this model, design recommendations are made to improve the efficiency of the studied liquid flooded compressors for heat pump applications.     

Thermal modeling of gas engine driven air to water heat pump systems in heating mode using genetic algorithm and Artificial Neural Network methods

The gas-engine driven air-to-water heat pump, type air conditioning system, is composed of two major thermodynamic cycles (including the vapor compression refrigeration cycle and the internal combustion gas engine cycle) as well as a refrigerant-water plate heat exchanger. The thermal modeling of gas engine driven air-to-water heat pump system with engine heat recovery heat exchangers was performed here for the heating mode of operation (in which it was required to model engine heat recovery heat exchanger). The modeling was performed using typical thermodynamic characteristics of system components, Artificial Neural Network and the multi-objective genetic algorithm optimization method. The comparison of modeling results with experimental ones showed average differences of 5.08%, 5.93%, 5.21%, 2.88% and 6.2% which shows acceptable agreement for operating pressure, gas engine fuel consumption, outlet water temperature, engine rotational speed, and system primary energy ratio.     

Hierarchical Graphene Foam for Efficient Omnidirectional Solar–Thermal Energy Conversion

Efficient solar–thermal energy conversion is essential for the harvesting and transformation of abundant solar energy, leading to the exploration and design of efficient solar–thermal materials. Carbon‐based materials, especially graphene, have the advantages of broadband absorption and excellent photothermal properties, and hold promise for solar–thermal energy conversion. However, to date, graphene‐based solar–thermal materials with superior omnidirectional light harvesting performances remain elusive. Herein, hierarchical graphene foam (h‐G foam) with continuous porosity grown via plasma‐enhanced chemical vapor deposition is reported, showing dramatic enhancement of broadband and omnidirectional absorption of sunlight, which thereby can enable a considerable elevation of temperature. Used as a heating material, the external solar–thermal energy conversion efficiency of the h‐G foam impressively reaches up to ≈93.4%, and the solar–vapor conversion efficiency exceeds 90% for seawater desalination with high endurance.     

多级水蒸汽喷射泵系统优化设计模型的研究

多级水蒸汽喷射泵多为大型设备工艺过程中提供需要的真空环境,是冶金、石化、制药、食品等行业的重要基础设备,泵的抽气性能及稳定性关系到工艺流程的进行和最终产品的质量.在单级泵抽气理论适用性分析以及对其进行修正的基础上,本文运用直接搜索法,以工作水蒸汽耗量最小为设计目标,统筹考虑泵级数、冷凝器设置、冷凝水流量等因素,对压缩比分配进行优化设计,使能耗最小.计算结果表明,采用压缩比优化分配方案的水蒸气喷射泵系统,能耗大幅度下降.