共查询到19条相似文献,搜索用时 46 毫秒
1.
2.
同时供冷供热双级压缩制冷热泵循环是1种新型热力循环,它能够同时对制冷、制热量进行调节,以满足用户的冷热量需求。本文建立了该循环系统的分析模型,并对其进行了研究,结果表明:在给定的传热温差下,影响该系统效率的主要因素是室外空气温度、制冷剂流量比;在低制冷剂流量比下,该系统产生损失的主要部位依次为热源侧换热器、热水加热器、第一节流阀、高压压缩机;在高制冷剂流量比下,该系统产生损失的主要部位依次为第二节流阀、热水加热器、高压压缩机、低压压缩机。通过在系统中增加1个经济器对该系统进行了优化,并对比分析了系统优化前后的效率和损失,结果表明:经济器能提高系统的效率,大幅度降低发生在第一节流阀和第二节流阀的损失,但对其他部件损失的影响很小。 相似文献
3.
利用经济分析方法建立了海水源热泵系统的经济分析模型,并对海水源热泵系统流程的成本进行计算,结果表明热泵机房的流成本最高,因此可以通过提高热泵效率等途径来减小流成本。建议以流成本最小作为约束函数,并将经济分析法用于海水源热泵系统的优化设计中。 相似文献
4.
5.
6.
欧阳禧玲 《建设科技(建设部)》2014,(14):40-43
随着生活水平的提高,人们对生活热水的需求量越来越大,太阳能热水系统在住宅中的运用也在越来越多的地区开始强制推行。本文总结了住宅太阳能热水系统常用的几种形式、特点并进行了分析比较和应用举例。选用何种形式的太阳能系统要根据住宅的类别、建筑外观要求、成本因素、使用要求(出水温度、费用支付等)和绿色星级标准等情况综合分析决策。 相似文献
7.
本文对太阳能热化学循环制氢过程进行了筛选,最终筛选出了两步和三步热化学循环中较成熟的Fe3O4/FeO循环和S-I循环2种典型过程.继而,计算了以上2种过程的理论能量效率,S-I循环的效率高达84.18%,而Fe3O4/FeO循环的理论能量效率并不高,仅33.78%,并将2种过程的实际效率与各自的理论能量效率进行了比较,为这2种过程能量效率的提高指明方向和限度. 相似文献
8.
本文通过对平板型太阳能空气集热器的理论分析,介绍不同的空气流道厚度、空气流速对空气集热器的散热损失及瞬时效率的影响,为优化设计太阳能空气集热器提供一定的设计依据。 相似文献
9.
樊瑛 《建筑热能通风空调》2016,(4):1-4,82
建立了常规区域供冷系统的分析通用模型,用TRNSYS软件建立了常规区域供冷系统的逐时分析模型,并基于上海某中央商业中心进行了案例分析。结果表明,采用逐时室外环境参数作为分析的基准参数更符合实际情况;在机组配置和基准参数相同的前提下,采用台数与流量控制相结合的控制策略时,系统效率均高于,且系统损失均小于单纯采用台数控制的控制策略;制冷机损率份额最大;其次是二次泵、冷却塔,两者相差不大;接下来依次为冷却水泵、一次泵、集水器、换热器等。另外,单位冷量的损失与效率均可作为不同区域供冷系统进行分析的评价指标。 相似文献
10.
冷却塔逆用已经在热泵制热系统中得到实际应用并取得了一定的节能效果。本文从热力学第二定律的角度,对冷却塔逆用作为低温热源的热泵制热系统进行了火用分析。构建了系统各部件火用分析数学模型,并结合实验系统现场测试数据进行分析,分析过程中采用火用损失、火用效率、火用损失率、火用损失系数评价指标综合评价。结果表明在系统制热工况下,末端空气处理机组与压缩机火用损失、火肭员失率明显高于整个系统中其他设备及部件,火用损失率分别为14%和12%,是整个系统改进的主要对象。该研究有助于诊断出系统主要设备的薄弱环节,并能对系统的节能潜力做出判断,为进一步优化系统指明方向。 相似文献
11.
The exergy output rate and exergy efficiency performances of an endoreversible intercooled regenerative Brayton cogeneration plant are optimized based on the model which is established using finite time thermodynamic in Part 1 of this paper. It is found that the optimal heat conductance allocation of the regenerator is almost zero. When the total pressure ratio and the heat conductance allocation of the regenerator are fixed, it is shown that there exist two optimal intercooling pressure ratios, and two optimal groups of the heat conductance allocations among the hot-, cold- and consumer-side heat exchangers and the intercooler, which correspond to a maximum dimensionless exergy output rate and a maximum exergy efficiency. When the total pressure ratio is variable, there exist two optimal total pressure ratios which correspond to a double-maximum dimensionless exergy output rate and a double-maximum exergy efficiency, also the corresponding exergy efficiency and exergy output rate are obtained. The effects of the total heat exchanger conductance and the consumer-side temperature on the double-maximum dimensionless exergy output rate and the double-maximum exergy efficiency are discussed. It is found that there exists an optimal consumer-side temperature which correspond to a thrice- maximum dimensionless exergy output rate, and the intercooling process is not necessary by taking exergy efficiency as the objective when the consumer-side temperature is high. 相似文献
12.
13.
《Planning》2017,(6):763-768
根据有限时间热力学理论,研究了具有热阻、热漏和非等熵压缩与膨胀等的内、外部不可逆性的高炉余能余热驱动恒温热源不可逆Brayton热电联产循环密度特性,并与输出率特性进行了比较。研究表明,分别存在最佳循环压比使得密度和效率取得最大值;以密度为目标,可以使循环的效率提高,设备体积缩小,相应地,循环压比增大,总输出率减小。还分析了各循环参数对密度和效率的影响,发现存在最佳用户侧温度且热漏不影响循环的密度。 相似文献
14.
Energy and exergy analysis of a Brayton cycle gas turbine power plant with regenerator, reheater and intercooler is carried out in this work. It has been found that the effects of the regenerator, intercooler and reheater are significant. Although, the energy analysis shows that the first law efficiency is more effective than the second law efficiency and there are significant losses in these components which cannot be neglected, and hence proper care should be taken for the size and operating conditions of these components. Efficiency of some components is 100% especially when energy balance is applied, while it is not 100% in the case of energy consuming/conversion systems like compressor, turbine, etc. The energy loss in reheater is zero while there is a small amount of exergy loss. The intrercooler has both energy and exery losses, so proper care should be taken in intercooler. 相似文献
15.
Chih Wu 《国际自然能源杂志》2013,34(2):77-82
The purpose of this paper is to define a finite-time closed Brayton cycle and apply it to an indirect gas-cooled nuclear reactor plant for its optimization. Practical engineering heat engine power optimization usually takes the form of determining minimum heat exchanger area per unit net power output or minimum cost per unit power output, rather than determining the maximum cycle efficiency. The objective function of the optimization described in this paper is specific power, power output per total heat exchanger surface area. The specific power output of a real indirect gas-cooled nuclear reactor plant coupled with its heat source and sink is analyzed. It is found that there is an upper bound on the specific power output of the nuclear power plant. This bound can guide the evaluation of existing real plants or influence design of future power plants. 相似文献
16.
17.
18.
风机盘管机组的分析与评价 总被引:1,自引:0,他引:1
利用分析方法,综合考虑传热、阻力的影响及不同形式能量在质量上的差异,结合实例对风机盘管机组进行了分析与评价。并依据提出的评价指标,进行了运行工况的优化分析。 相似文献