共查询到20条相似文献,搜索用时 114 毫秒
1.
变风量空调系统中的实时优化节能控制 总被引:8,自引:1,他引:7
在对变风量空调系统局部控制的分析基础上,利用其变风量末端风门的开度作为各区域相对负荷的指示信号,提出送风静压的实时优化控制方案;同时,针对新的ASHRAE通风标准,还提出了基于室内人数检测和焓控制的新风实时优化控制方案。试验结果证明,同常规的控制方案相比,在保证室内热舒适性和空气质量的前提下,这两个方案分别有较好的节能作用。综合采用两种优化方案,系统不仅能够达到节能的目的,而且在较小负荷情况下能够提高室内空气的品质。 相似文献
2.
3.
合适的空调系统能够为地下商业建筑营造舒适的人员活动环境.在对地下商业建筑负荷进行分析的基础上,提出适合地下商业建筑的空调系统节能设计方案,该方案可实现提高舒适性和节能的目的. 相似文献
4.
5.
高湿空气在高温高压区域内的热物性计算及分析 总被引:3,自引:1,他引:3
首先介绍了湿空气热物性的3种计算方法:工程计算法、基于维里方程的余函数计算法和基于R-K方程的余函数计算法,继而采用这3种方法对湿空气在不同压力、温度、湿度下的比容、焓值进行了计算,还对湿空气达到饱和状态时的含湿量进行了计算,计算完成后对计算结果进行了比较分析;结论认为3种方法对比容的计算不会产生很大偏差;压力、温度、湿度在不同的区域对焓值的影响各有不同;采用基于R-K方程的余函数计算法计算的饱和含湿量要高于采用工程计算法所计算的饱和含湿量5%~10%,很好的反映了实际的湿化情况。图3表2参11 相似文献
6.
太阳能液体除湿空调系统中除湿器型式的选择 总被引:6,自引:2,他引:6
太阳能液体除湿空调系统是一种利用太阳能等低温热源的节能空调系统。除湿器直接影响太阳能液体除湿空调系统的性能。本文从焓湿图、蓄能、MR的选取和除湿效果等几个方面对目前被广泛应用的两种典型的除湿器进行了比较分析。 相似文献
7.
采用室内热舒适性控制的变风量空调系统节能控制研究 总被引:4,自引:0,他引:4
在对变风量空调系统及控制系统分析的基础上,利用DDC控制器可采集多点和多种信号的优点,提出采用室内热舒适性控制取代室内温度控制的控制方案。仿真试验结果证明,同常规的室内温度控制方案相比,室内热舒适性控制方案可以较好地改善室内的热舒适性,同时,在保证室内热舒适性前提下,采用室内热舒适性控制方案不仅能够保证控制的稳定性,而且有较好的节能作用。 相似文献
8.
以国家电网公司客户服务中心北方基地工程研发楼二中庭为研究对象,运用CFD商用计算软件Fluent Airpak3.0,结合PMV-PPD指标对其分层空调方案热舒适性和气流组织进行模拟研究,结果表明分层空调设计方案应用于高大空间建筑,不仅能保证工作区合理的气流组织设计与热舒适性,而且对降低初投资、节省运行费用、建筑节能有重大意义。同时,该模拟研究对高大空间建筑空调系统节能与优化设计具有重要的指导意义。 相似文献
9.
10.
11.
This paper presents a model-based optimal ventilation control strategy for multi-zone VAV air-conditioning systems aiming at optimizing the total fresh air flow rate by compromising the thermal comfort, indoor air quality and total energy consumption. In this strategy, one scheme is used to correct the total fresh air flow rate dynamically by utilizing the unvitiated fresh air from the over-ventilation zones based on the detected occupancy of each zone and the related measurements. At the meantime, another scheme is developed to optimize the temperature set point for the temperature control of critical zones with the aim at reducing the variation of the required fresh air fractions among all the zones and further reducing the total fresh air intake from outdoors for energy saving when the first scheme is implemented. This scheme is based on a constructed cost function relating thermal comfort, indoor air quality and total energy consumption together while the cost function is calculated based on the prediction of system responses using dynamic simplified models. Genetic algorithm is used for optimizing the temperature set point of critical zones in the optimization process. This strategy was evaluated in a simulated building and air-conditioning environment under various weather conditions. 相似文献
12.
《Solar Energy》2013
In this paper, a solar combi-system which consists of solar collectors and a carbon dioxide heat pump is proposed and investigated through simulation and optimization. Performance analysis and comparison are primarily conducted to show the feasibility and reasonability of using a CO2 heat pump as an auxiliary heater under local weather conditions. Then, a system model with a test building in TRNSYS is developed for performance optimization. The most influential variables are identified using influence and sensitivity analyzes of single parameters. Subsequently, a multi-parameter optimization using the high-weight parameters is carried out to obtain a final design result. The simulated results of the optimized case show that the average coefficient of performance of the CO2 heat pump is 2.38, and the solar fraction of the system is 69.0% for the entire heating season. The time when a comfortable temperature level can be achieved in the indoor environment accounts for 81.6% of the entire heating season. Furthermore, the performance characteristics of the proposed system are evaluated in terms of the thermal balance, fraction of the thermal energy saving, feasibility of net zero energy, economic factor, and CO2 emissions reduction. 相似文献
13.
Simple tool to evaluate energy demand and indoor environment in the early stages of building design 总被引:1,自引:0,他引:1
A simplified building simulation tool to evaluate energy demand and thermal indoor environment in the early stages of building design is presented. Simulation is performed based on few input data describing the building design, HVAC systems and control strategies. Hourly values for energy demand and indoor temperature are calculated based on hourly weather data. Calculation of the solar energy transmitted through windows takes into account the dependency of the total solar energy transmittances on the incidence angle, shades from far objects and shades from the window recess and overhangs. Several systems including heating, cooling, solar shading, venting, ventilation with heat recovery and variable insulation can be activated to control the indoor temperature and energy demand. Predicted percentages of dissatisfied occupants are calculated for a given time period to support decisions concerning the thermal indoor environment. The simplified building simulation tool gives reliable results compared to detailed tools and needs only few input data to perform a simulation. The tool is therefore useful for preliminary design tasks in the early design stages where rough estimates of the building design are given and rough estimates of energy use and thermal indoor environment are needed for decision support. 相似文献
14.
15.
16.
创造健康舒适的生活环境是人类共同的愿望,也是建筑节能的基础和目标。采用新技术对建筑围护结构进行高水平的保温隔热是达到现行住宅节能设计标准提出节能50%的主要措施。在外墙使用高效保温材料的复合墙体是墙体节能的主要发展方向。针对墙体外保温和内保温的不足,设计出了一种新型的复合保温砌块。利用防护热箱法和数值模拟方法得到了砌块热绝缘系数最大时的砌块的结构。并对该种砌块的保温性能、隔音性能和经济性进行了初步研究,论证了此种砌块所具有的优越性及推广应用的可行性。 相似文献
17.
In this paper a scheme has been proposed to maintain the temperature and the humidity, in each of the rooms served by a central Air Conditioner (AC) unit, close to the targeted values, and reduce the electrical energy intake of the AC compressor. The upper limits of the comfort zone, typically marked at a temperature of 25 °C and a relative humidity of 70%, are used as the targets. It should be noted that a conventional AC system controls humidity in its own way without giving the users any scope for changing the set point for the targeted humidity unlike the scope it offers to change the set point for the targeted temperature through a thermostat. But in this work this limitation has been taken into cognizance and overcome to a great extent using fuzzy logic to represent the intricate influences of temperature on the humidity of the space being cooled and correct the thermostat setting. In the developed scheme, the sensor captured temperature and humidity readings for each room are compared against the targets at the selected intervals of time, and the corresponding differences are fuzzified. These differences are used to decide the fuzzy qualifier, which is decoded into a crisp value that is the change required in the setting of the thermostat of the AC. As a result, each room will maintain a temperature near 25 °C and a relative humidity near 70% while the compressor will remain off for an appreciable period leading to a saving of energy. Though a thermostat with programmable setting for an AC unit dedicated to a single room has been reported in the literature, the same for a central AC unit that serves more than one room appears to have not yet been presented. The advantages of the scheme proposed for programming a thermostat under central air conditioning system are that it (i) requires for each room only a pair of input data i.e. the sensor captured temperature and humidity readings for each room, (ii) controls humidity indirectly and (iii) leads to a saving in energy consumption while maintaining a comfortable level of cooling in each of the rooms though their occupancy, size and the thermal conditions are different from one another. 相似文献
18.
19.
A method for simulating predictive control of building systems operation in the early stages of building design is presented. The method uses building simulation based on weather forecasts to predict whether there is a future heating or cooling requirement. This information enables the thermal control systems of the building to respond proactively to keep the operational temperature within the thermal comfort range with the minimum use of energy. The method is implemented in an existing building simulation tool designed to inform decisions in the early stages of building design through parametric analysis. This enables building designers to predict the performance of the method and include it as a part of the solution space. The method furthermore facilitates the task of configuring appropriate building systems control schemes in the tool, and it eliminates time consuming manual reconfiguration when making parametric analysis. A test case featuring an office located in Copenhagen, Denmark, indicates that the method has a potential to save energy and improve thermal comfort compared to more conventional systems control. Further investigations of this potential and the general performance of the method are, however, needed before implementing it in a real building design. 相似文献
20.
Energy-conscious design of school buildings can contribute to significant energy savings and improve the students’ learning environment. The purpose of this research is to formulate design recommendations for school buildings in the hot–humid climatic zone and assess the influence of different design variables on their energy consumption. A base-case classroom was constructed by taking commonly used values for each design variable. Using computer simulation techniques, these variables were modified one by one to find the value that minimized energy consumption, while keeping thermal and visual comfort in the room. Based on these tests, the recommended value for each design variable to achieve a high performance classroom, was determined. Comparative tests were done to determine which variables have greatest impact on the energy consumption and thermal comfort in the classroom, and how their absolute influence depends on the order of implementation of each improvement. A complex interdependence among the design variables was found, but strong conclusions for energy savings could still be reached. 相似文献