内波纹管太阳能热水器的实验研究

给出了内波纹管的技术参数和结构。对以内波纹管做集热器芯体的太阳能热水器进行了测试,给出了测试结果,表明平均日效率提高了６．６％。     

分体式太阳热水器的热特性

分体式太阳热水器的热特性李元哲现有太阳热水器用于楼房住宅，一般只能安装在楼顶。但对高层住宅和不少多层住宅来说，楼顶往往不能或不足以安装足够的热水器，其余能开发利用的地方只有楼房的南立面。而在南立面安装的热水器，必须满足在能提供足够热水的前提下，不占或...     

光控非承压分体式太阳能热水器设计及应用

光控非承压分体式太阳能热水器利用光照强弱及持续时间自动控制水流的无压力循环、回流,采用集热管底部进水,集热管与水直接进行热交换,较好地克服了一体式太阳能热水器的集热管易结垢、水箱保温性能差、使用范围窄及承压分体机易泄漏、价格昂贵等缺点,采用微压传感器实时控制各种用水需要,避免了承压分体机所采用的冷水顶热水方法的局限性。通过对整机的结构、工作原理、控制程序及应用实例的详细论述,阐明了该机不仅具有承压分体机的广泛适应性,而且具有非常高的性价比和极低的自身能耗。     

分体式太阳能热水器

1 分体式太阳能热水器简介 分体式太阳能热水器系统集热部分在室外,其它部分(如水箱、控制器、电加热等部件)在室内,控制直观,使用方便.室外集热器占地面积小,可以安装在屋顶或南阳台,方便高层住宅使用.     

管板式太阳能热水器的性能分析

本文详细介绍了管板式太阳能热水器的原理、结构和安装条件、着重分析了平衡状态的传热模式、性能参数影响因素，并对计算结果做了必要的讨论和分析     

蜂窝热管平板式太阳能热水器的实验研究

把蜂窝技术和热管技术结合起来应用于平板式太阳能热水器，可以大大减少热损失，提高日平均效率。经多次实验证明，蜂窝热管平板式太阳能热水器的日平均效率可以比真空管式热水器的高，热损系数则要小很多，具有推广应用价值。     

江苏太阳能热水器的应用

一、引言太阳能是一种清洁能源,不污染环境,不破坏生态。目前太阳能利用最广泛最普及的要算太阳能热水器,为探索太阳能热水器的应用所带来的经济效益,本文以南京某太阳能设备厂的JZX-3型平板型直流式太阳能集热器为例,进行集热量和产水量的预测和经济效益的分析估算,供开发、推广、应用时参考。二、太阳能热水器集热量和产水量的预测 1989年JZX-3型平板型直流式太阳能集热器第二季度国家抽查检定FR(τα)=0.627,FRU_L=7.36W/m~2·℃,产品质量符合国家标准,由于选用优质铝合金寿命长,可减少用镀锌壳体作材料所需每年除锈刷漆的维修费用。集热器的安装需要在最佳倾角范围,一般     

内插式真空管太阳能热水器热特性理论及实验研究

设计了一种内插式真空管热水集热器,通过对其能量转换、传输特性研究,建立了内插式真空管集热器的热特性分析模型,并对不同设计参数和气候条件对内插式真空管热特性的影响进行了分析。结果表明,设计的集热器理论热效率最大可达79.5%,但其受环境温度、集热器工作温度等影响较大。此外,设计了由14只内插式真空管组成的太阳能热水器,采用迟滞算法将热水温度控制在50～55℃,实验结果表明,样机系统的日热效率可达55.0%,样机输出热水近120 kg,具有较好的实用价值。     

防倒流循环家用太阳能热水器的实验研究

以普通平板型自然循环家用太阳能热水器做对比,对作者设计的防倒流循环家用太阳能热水器进行了实验研究,结果表明：与普通平板型自然循环家用太阳能热水器相比,防倒流循环家用太阳能热水器具有较低的热损系数,且平均日效率较高。     

带辅助能源的家用太阳能热水器的试验研究

介绍了一种以电能和房屋采暖热源为辅助能源的全天候家用直流式太阳能热水器，夏秋季可节约常规能源４０％左右。     

Refrigerant-charged integrated solar water heater

The performance of two R-11-charged integrated solar water heater collectors was investigated experimentally for forced and natural circulation water flows. The heat transfer from the refrigerant loop to the hot water storage tank took place through a condenser of novel design integrated within the collector frame. The effect of the condenser inclination on the system efficiency was remarkable for natural circulation water flow but had no significant effect for forced circulation flow. The difference in thermal response between the refrigerant and water loops caused buildup of stored energy in the condenser. This energy affected the buoyancy forces and generated flow pulsation that caused a harmonic-like variation of the system efficiency. This effect vanished with forced water circulation flow. The system efficiency varied between 20 and 50% depending on the solar insolation.     

真空玻璃盖板热管平板式太阳能热水器的研制

介绍了研究成功的采用真空玻璃盖板的热管平板式太阳能热水器,测试了其性能,并与全玻璃真空管太阳能热水器和蜂窝热管太阳能热水器进行了比较。实测得到,真空玻璃盖板热管平板式热水器的日平均效率比后两分别大13．3％和6．5％,平均热损系数比后两分别小52．5％和21．5％。真空玻璃盖板平板式太阳能热水器性能优越,有很好的应用前景。     

家用太阳热水器与太阳热水系统的技术经济比较

分析了户用太阳热水器和太阳热水系统工程的经济技术特点,对两者成本构成、项目财务净现值、投入回收期和财务内部收益率等有关指标进行了经济技术比较.分析比较表明,太阳热水系统与家用热水器相比,节省安装占地,与建筑相结合得好,在降低成本,缩短投资回收期,提高经济效益方面有明显的优势.     

A solar water heater with a built-in latent heat storage

In this paper, we have investigated the performance of a novel built-in storage type water heater containing a layer of PCM-filled capsules at the bottom. The PCM layer is introduced with a view of getting hot water during off-sunshine hours. The moving solid-liquid boundary layer problem for the PCM material is simplified to a stationary boundary layer problem, and the effect of latent heat is included in the specific heat by replacing the semi-melted PCM by a fictitious solid. The performance of the water heater is then predicted analytically for two depths of PCM and for different flow rates, both constant and intermittent. The case of sudden withdrawal of water over very short periods is also studied.     

Performance analysis and experimental validation of a vee-corrugated absorber integrated collector storage solar water heater

This paper focuses on enhancing the energy collection efficiency of an integrated collector storage solar water heater (ICS SWH) by vee-corrugating the absorber and optimizing the design for the vee-included angle through simulation and experimental study. This paper presents an efficient algorithm for analyzing a vee-corrugated absorber ICS SWH using Engineering Equation Solver Software. For validating this algorithm, two models of ICS SWH systems have been fabricated: one with a flat absorber and the other with a 60° vee-included angle corrugated absorber with eight corrugations. The basic purpose of the fabrication of the flat absorber ICS SWH system was to approximate the absorptivity of the absorber. A typical value of 0.68 was estimated for the absorptivity of the aluminum absorber coated with nonselective black paint. After the experimental investigation of the 60° vee-included angle ICS SWH system, it was found that the real-time readings were in close agreement with the numerical model readings. For comparison with the previous work, a five-corrugation system with an approximate 90° vee-included angle with the same projected dimensions was modeled and the efficiencies of both the models for the time from 7 a.m. to 3 p.m. were calculated. The efficiency of the eight-corrugation model was 42.56%, which was better than the previous work of the five-corrugation model, with a 38.86% efficiency for the same ambient conditions. Also, it was theoretically deduced that we had an optimized system at 18 corrugations and a vee-included angle of 28.78°.     

An experimental investigation into the performance of a domestic forced circulation solar water heater under varying operating conditions

An experimental investigation is carried out on a forced circulation solar water heater to assess its performance under various operating conditions. The system consisted of two identical collectors of total absorber area of 3.45 m² and a storage tank of 200 litre capacity. Experiments were carried out during clear days with and without system loading for two water mass flow rates through the collector; namely 0.1305 kg/s and 0.06525 kg/s. The system was operated without thermostat control and with thermostat control at maximum and minimum settings. The collector efficiency improved with system loading. The improvement was better with increased hot water withdrawal from the system.     

Model-based design and analysis of heat pipe working fluid for optimal performance in a concentric evacuated tube solar water heater

In this study, a semi-dynamic model of a concentric evacuated tube solar water heater is developed to investigate the effect of working fluid design on technical and economic performance of a typical solar water heater in a household located at Sydney, Australia. The model is validated against experimental data. The effects of using water, ammonia, acetone, methanol, and pentane as working fluids of the built-in heat pipe are discussed comparatively during a typical day of operation. Water is identified as the best working fluid amongst the others. The variation of thermal resistance and critical heat flux of the heat pipes due to change in weather condition is presented and discussed. Three hypothetical working fluids are then proposed for further analysis which led to a working fluid design superior to water in performance. It is shown that the performance of the solar water heater can be significantly enhanced up to 28% and 50% from economical and technical points of view, respectively.     

真空管式太阳热水器得热量的实验研究

对某型号真空管式太阳热水器进行多天的热性能测试,采用最小二乘法拟合出太阳热水系统能量方程系数,求出该型号太阳热水器的能量方程,同时进行误差和敏感性分析,指导试验设计.     

Review on solar water heater collector and thermal energy performance of circulating pipe

The effect of thermal conductivity of the absorber plate of a solar collector on the performance of a thermo-siphon solar water heater is found by using the alternative simulation system. The system is assumed to be supplied of hot water at 50 °C and 80 °C whereas both are used in domestic and industrial purposes, respectively. According to the Rand distribution profile 50, 125 and 250 l of hot water are consumed daily. The condition shows that the annual solar fraction of the planning functions and the collector's configuration factors are strongly dependent on the thermal conductivity for its lower values. The less dependence is observed beyond a thermal conductivity of 50 W/m °C for the solar improper fraction and above 100 W/m °C for the configuration factors. In addition, the number of air ducts and total mass flow rate are taken to show that higher collector efficiency is obtained under the suitable designing and operating parameters. Different heat transfer mechanisms, adding natural convection, vapor boiling, cell nucleus boiling and film wise condensation is observed in the thermo-siphon solar water heater with various solar radiations. From this study, it is found that the solar water heater with a siphon system achieves system characteristic efficiency of 18% higher than that of the conventional system by reducing heat loss for the thermo-siphon solar water heater.