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通过对供热机组凝结水含氧量高的研究分析。采用从凝汽器向热力系统补入化学补充水的方式,能有效降低凝结水含氧量,并且补充水以雾化状态进入凝汽器,可明显改善凝汽器真空。 相似文献
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基于等效焓降法定量分析了两种补水方式的热经济性差异,通过实例计算结果得出,采用补充水补入凝汽器的方式,可以明显提高机组经济性。对补充水补入凝汽器的补水量和补水进入方式问题进行讨论,补充水应以雾化状态喷入凝汽器的喉部,形成一个均匀分布的雾化带,使其合理利用排气余热,降低冷源损失,并利用低品位抽汽加热,减少高品位抽汽量,提高回热经济性,同时可加快气体的逸出,为除氧创造有利条件。 相似文献
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一、概述 由于电厂火电机组存在汽水损失,为维持其连续运行,必须经常向热力系统补充化学水。补水方式有两种:一是按传统方法通过除氧器补入热力系统;一是通过凝汽器补入热力系统。后一种补水方式,可以使补水在凝汽器内实现初步除氧,降低对低压加热设备的氧腐蚀程度。若补水以喷雾状态进入 相似文献
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介绍了当前节能降耗的迫切需要和转子组合式强化传热装置棗"洁能芯"的技术原理.论述了2号机组甲、乙侧凝汽器性能试验内容,试验方法和试验计算结果,计算分析了安装转子组合式强化传热装置后凝汽器性能及机组经济性.安装转子组合式强化传热装置后,凝汽器端差降低2.79℃,真空提高2.97 kPa,冷却水流量减小9.8%;凝汽器在相同进水温度、相同真空下,机组带负荷能力提高19.7%;凝汽器水阻增加19.52 kPa.工业试验和计算分析结果表明,转子组合式强化传热装置应用于电厂凝汽器可提高其性能. 相似文献
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从提高凝汽器换热系数出发,在保证真空不变的前提下,引出临界污垢热阻的概念,通过分析临界污垢热阻和循环浓缩倍率的关系,将强化传热和循环水节水问题结合起来研究,并通过实例计算出相应的节水量。研究表明,在凝汽器真空和其它换热条件不变时,增大凝汽器换热管汽侧换热系数可以增大临界污垢热阻,从而提高循环水的浓缩倍率,达到循环水系统节水的目的,并且带来可观的节水效益和环保效益。文中分析了某300 MW机组凝汽器采用强化传热管后,汽侧换热系数显著增大,在达到原设计真空下,该机组每年因此可以节水约86.9×104t。 相似文献
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电厂水环式真空泵冷却系统的问题及其对机组出力的影响 总被引:9,自引:0,他引:9
通过对电厂中常用的水环式真空泵冷却系统运行实际情况的分析研究,指出其运行中存在但常被忽视的问题:由于真空泵冷却水温升高而导致的抽气能力严重降低,使机组背压升高,出力下降。文章提出凝汽器的压力实际受到两个瓶颈的限制:一是循环水的温度,二是真空泵的极限工作压力,而这一点常没有被足够的注意,导致凝汽器压力明显升高。由于凝汽器压力对机组运行的出力和经济性影响很大,文章提出了对真空泵冷却系统改进的建议,即尽量降低真空泵冷却水入口温度,在平时运行时应密切注意真空泵热交换器的运行状况。图3 相似文献
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R. Harish E.E. Subhramanyan R. Madhavan S. Vidyanand 《Applied Thermal Engineering》2010,30(14-15):2051-2057
In sea water based once through cooling water system for power plants, sea water is pumped through the condenser and the return hot water is let back to sea. The cooling water pumps (CWP) in power plants generally operate at constant speed, pumping variable quantities of water depending on the tide level in the sea. The variable flow causes variation in condenser back pressure resulting in changes in the turbine cycle heat rate. If the pump speed is controlled using a variable frequency drive (VFD) to maintain design flow irrespective of the tide level, the CWP power consumption can be reduced compared to the case with constant speed CWP. However, the turbine cycle heat rate benefit that could have accrued at tide levels above the pre defined level (for fixing the CWP head) with constant speed CWP would have to be sacrificed. This paper provides a theoretical model with a typical case study to establish viability of providing VFD for CWPs in power plants with sea water based once through condenser cooling water system. 相似文献
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Solar heat at moderate temperatures around 200 °C can be utilized for augmentation of conventional steam-injection gas turbine power plants. Solar concentrating collectors for such an application can be simpler and less expensive than collectors used for current solar power plants. We perform a thermodynamic analysis of this hybrid cycle. High levels of steam-to-air ratio are investigated, leading to high power augmentation compared to the simple cycle and to conventional STIG. The Solar Fraction can reach up to 50% at the highest augmentation levels. The overall conversion efficiency from heat to electricity (average over fuel and solar contributions) can be in the range of 40–55% for typical candidate turbines. The incremental efficiency (corresponding to the added steam beyond conventional STIG) is in the range of 22–37%, corresponding to solar-to-electricity efficiency of about 15–24%, similar to and even exceeding current solar power plants using higher temperature collectors. The injected water can be recovered and recycled leading to very low water consumption of the cycle, but a very low cost condenser is required to make water recovery feasible. 相似文献
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Cold-end systems are heat sinks of thermal power cycles, which have an essential effect on the overall performance of thermal power plants. To enhance the efficiency of thermal power plants, multi-pressure condensers have been applied in some large-capacity thermal power plants. However, little attention has been paid to the optimization of the cold-end system with multi-pressure condensers which have multiple parameters to be identified. Therefore, the design optimization methods of cold-end systems with single- and multi-pressure condensers are developed based on the entropy generation rate, and the genetic algorithm (GA) is used to optimize multiple parameters. Multiple parameters, including heat transfer area of multi-pressure condensers, steam distribution in condensers, and cooling water mass flow rate, are optimized while considering detailed entropy generation rate of the cold-end systems. The results show that the entropy generation rate of the multi-pressure cold-end system is less than that of the single-pressure cold-end system when the total condenser area is constant. Moreover, the economic performance can be improved with the adoption of the multi-pressure cold-end system. When compared with the single-pressure cold-end system, the excess revenues gained by using dual- and quadruple-pressure cold-end systems are 575 and 580 k$/a, respectively. 相似文献
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在传统电冰箱的基础上,另独立设置2个保温箱贮存冷热饮用水。冷水制取是在冷水箱中设置蒸发器,将冷水箱中的水制冷。热水制取是在热水箱中设置逆流套管式冷凝器,利用制冷系统的排热量将饮水机中的水加热到一定温度,如温度不够则再通过电加热器,可将饮用水加热至沸腾,冷凝管通热水箱后可采用风冷式和水冷却两种方式相结合。根据设计和理论计算,多功能电冰箱的冷凝器可将饮用水加热到65℃左右,再用电加热器,可将饮用水加热至沸腾,比市场上纯粹用电加热的饮水机可节电22.31W;利用制冷系统将冷水箱中的水制冷,每产生4℃冷饮用水2L比市场上一般的压缩式制冷饮水机可节约大约2.3×105J的能量。 相似文献
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A novel heat pump and power generation integration system (HPPGIS) using solar energy as a low temperature heat source was presented in this study. This system could be operated in both an organic Rankine cycle power generation (ORC‐PG) mode and a reverse Carnot cycle heat pump (RCC‐HP) mode. Compared with a single heat pump and power generation system, this system improved the utilization efficiency of solar energy, thus showing potential for the generation of economic benefits. Contrastive analyses of different working fluids using ORC‐PG and RCC‐HP systems were conducted first, leading to the selection of R142b and R245fa as optimal fluids. Then, an experimental investigation of the system was carried out under different conditions. A heat pump and ORC system model was proposed and validated by comparing experimental and simulated values. The experimental results indicated that the HPPGIS had good feasibility and stability in both modes. In the ORC‐PG mode, HPPGIS had a power output of 1.29 kW and a thermal efficiency of 4.71% when the water inlet temperature of the evaporator was 90.03°C. In the RCC‐HP mode, HPPGIS had a COP of 3.16 and a heat capacity of 33.24 kW when the water outlet temperature of the condenser was 106.23°C. 相似文献
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Peter Meibom Juha Kiviluoma Rüdiger Barth Heike Brand Christoph Weber Helge V. Larsen 《风能》2007,10(4):321-337
The paper analyses the economic value of using electric heat boilers and heat pumps as wind power integration measures relieving the link between the heat and power production in combined heat and power plants. Both measures have different technical and economic characteristics, making a comparison of the value of these measures relevant. A stochastic, fundamental bottom‐up model, taking the stochastic nature of wind power production explicitly into account when making dispatch decisions, is used to analyse the technical and economical performance of these measures in a North European power system covering Denmark, Finland, Germany, Norway and Sweden. Introduction of heat pumps or electric boilers is beneficial for the integration of wind power, because the curtailment of wind power production is reduced, the price of regulating power is reduced and the number of hours with very low power prices is reduced, making the wind power production more valuable. The system benefits of heat pumps and electric boilers are connected to replacing heat production on fuel oil heat boilers and combined heat and power (CHP) plants using various fuels with heat production using electricity and thereby saving fuel. The benefits of the measures depend highly on the underlying structure of heat production. The integration measures are economical, especially in systems where the marginal heat production costs before the introduction of the heat measures are high, e.g. heat production on heat boilers using fuel oil. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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Most pumped-storage power plants have the capability to operate as synchronous condensers. As such, they can be brought online very quickly to support power system load requirements. However, one of the effects of making a rapid transition from synchronous condenser operation to turbine/governor operation is an initial reverse power flow into the machine. This reverse power flow can be very undesirable at a time when the power system is calling for load support. On weak or isolated power systems, this reverse power flow can lead to objectionable voltage and frequency dips in the power system. With the proper utilization of a static frequency converter (SFC) and its associated controls and auxiliary switchgear systems, the reverse power flow resulting from a transition from synchronous condenser operation can be eliminated. This paper describe a method by which an SFC system can be used to make this rapid load response in pumped-storage power plants without incurring a reverse power flow and to provide additional instantaneous short term power to support the grid 相似文献