River Water Quality Comprehensive Evaluation for Water Source Heat Pump

River water quality is one of the important conditions must be considered when river water source heat pump is used. It is also the key factor of efficiency of river water source heat pump. Based on analysis of the water quality factors which influence the river water source heat pump heat exchanger fouling, the main quality indicators and value are conformed. Using fuzzy comprehensive evaluation method and the actual monitoring data, quality classification of river water which is the source of water source heat pump is analyzed. For the difficulty of multiple indicators which need to detect and meet the related national standard in practical engineering application, the definition of scaling potential value is put forward. As the water quality comprehensive evaluation index of water source heat pump, the scaling potential value not only can consider the influence of the main water quality parameters on water source heat pump heat exchanger fouling, but also can conveniently and quickly provide direct basis for water quality judgment and system selection in the engineering application.     

Analysis of Yangtze River Water as a Potential Source for Developing a Water Source Heat Pump in Chongqing

Characteristics of smoke flow and fire spread in a patio space of a high-rise building were studied to investigate their influences on fire compartment and safety evacuation. Fire development model was established and fire scenarios were designed to simulate fire and smoke spread by CFD software numerically based on concepts of fire performance-based design in a high-rise building with double patio space, whose height are 74. 65 m and 55. 95 m, respectively. Simulation results show that in all fire scenarios, performance targets for safety evacuation for people in each floor was satisfied, if smoke was extracted naturally using the patio space. Hang walls mounted in corridors around the patio space prevent smoke flowing out smoothly, shorten the coming of the risk time and increase fire danger. Using chimney effect, it is preferred to adopt natural smoke exhaust method in a high rise building with patio space.     

Effects of Cold Discharge of Lake Water SourceHeat Pump Systems on Lake Phytoplankton

According to small environmental capacity and fragile ecosystem of lake, the lakes in Chongqing Section of Three Gorges Reservoir Region were taken as a case. The effects of cold water discharge of lake water source heat pump systems on lake algae and Chla were studied with the method of physical simulation. It was found that cold discharge discouraged the growth of algae, and the critical temperature of algae growth was between 4.5℃ and 6.2℃. There was significant impact of cold discharge on dominant populations and its proportional change of algae. And it would reduce the number of algal populations and the content of Chla. Furthermore, the cold discharge would have great influence on total quantity of phytoplankton. And the higher the content of nitrogen and phosphorus of raw water was, the greater of the effect extent was.     

连栋温室水源热泵热水供暖系统研究

本文利用水源热泵热水供暖系统,对连栋温室加温进行了系统研究。通过自行设计的自动控制和耗热量计量系统,对连栋温室水源热泵热水供暖系统的耗热量、加温效果、温室内外环境进行了实测,得到较准确的连栋温室加温系统热负荷设计参数取值,论证了该供暖系统的可行性与经济性。本研究对水源热泵这项新能源技术在农业领域的应用具有重要的意义,该研究可减少连栋温室水源热泵加温系统一次性投资和运行成本,降低能源消耗。     

Energy Efficiency of Water Transportation System for Surface Water Source Heat Pump

The forms of water transportation, arrangement and operation of pumps contribute to the water transportation energy consumption, which influences the energy-saving effect of surface water source heat pump. The relation between the pumping height and energy consumption of pumps is found by analyzing the model of pump energy consumption. The concept and calculation of critical pumping height is presented considering the limited rate of system energy efficiency. Based on the principle that the pump power changes with water flow rate, the determination of pumps arrangement of one or two stage pumps is described with a concrete example. The influence of water flow rate on heat pumps and water pumps is analyzed, and the energy efficiency of constant and variable water volume are compared. The operation way of this example is concluded for the optimal system energy efficiency. It is found that there is a critical pumping height for the energy-saving effect of surface water source heat pump compared with the traditional system. Moreover, the operation strategies should be determined by the system optimal model since the energy consumptions proportions of heat pumps and water pumps are variable.     

水源热泵在温室加温中的应用研究

采用多层覆盖、减小直接加热空间的温室节能设计措施,设计建造了试验温室,在水源热泵热风加温条件下,对试验温室的温度、空气相对湿度、水源热泵的实际制热系数进行了测定,对试验温室采用水源热泵加温的节能效果进行了评价,结果表明：夜间水源热泵加温条件下,温室东西方向的水平温度分布均匀,南北相距12m的水平方向上存在着0.9℃的温差,中部距地面2.2m的垂直空间上平均存在1℃的温差,24:00—08:00,空气相对湿度低于80%;试验用水源热泵实际热系数为3.31。与燃煤锅炉热水加温的玻璃温室相比,试验温室采用水源热泵加温相对节能46.5%,直接加温成本较燃煤锅炉加温高82.2%,经计算,当试验温室与对照玻璃温室面积相等时,采用水源热泵加温可相对节能69.1%,直接加温成本仅较燃煤锅炉加温的玻璃温室高5.8%。     

Influence of Distributed Drainage on Reservoir Water Temperature Field Under Reservoir Water Source Heat Pump System

By adopting fluid calculation software to establish three dimensional reservoir model and simulating reservoir's natural temperature on design day, the measured temperature was used to correct and treated as the initial condition. According to the annual hourly calculation load of villa cluster, dynamic water temperature and flow were used as boundary conditions. Inputted water surface heat transfer conditions were identified by user defined function based on the data of typical meteorological year. For the distributed drainage combining the discharge network and rainwater pipe network and traditional integrated drainage of reservoir water source heat pump system, dynamic numerical simulation of the water temperature field was conducted. The results show that water's temperature rises 0.33℃ weekly when integrated drainage is adopted and the temperature rises 0.16℃ when distributed drainage is adopted. There is obvious heat accumulation phenomenon when continuous drainage in narrow area works. The simulation of intake water temperature shows that below perennial water level 4.6m depth, the intake water temperature is between 27~23.5℃ from July to October, in which the heat pump system operates efficiently.     

Operational Analysis of Open Untreated Sewage Source Heat Pump System

The effective sewage intake technology is prerequisite for the untreated sewage source heat pump system to run steadily. In terms of the insufficiency of current sewage intake technologies, an open sewage intake integration technology is proposed. The mathematical model and the distinguish basis of critical state are established for the sewage intake characteristic by defining some important operating parameters, such as the blocking coefficient, the contamination density and the section coefficient. Furthermore, the change rule of each critical operation parameter is observed along with the various initial parameters. The result can provide the theoretical basis to design the open intake integration technology.     

Analysis of the Temperature Limit of Dynamic Water Intake of Open loop Surface Water Source Heat Pump Systems

Energy consumption of water intake is one of the key factors for energy saving in the application of the open loop surface water heat pump system. An energy efficiency ratio coupling model for open loop surface water source heat pump systems was established on the basis of the energy consumption model for the water intake and the heat pump units. According to energy saving rate and regulation of energy consumption of water intake, dynamic temperature limits of water intake in different water supply temperature of cooling tower and different pump head were proposed so as to find a calculation method of temperature limits of water intake of open loop surface water heat pumps. Moreover, the energy saving rate of surface water source heat pump systems compared with traditional air conditioning systems under various condition was also calculated.     

Modeling and Experimental Analysis on CO2 Heat Pump in Low Temperature Ambient

The use of CO2 air-source heat pump for heating feasibility in low temperature was analyzed. A static simulation model for the CO2 heat pump was developed, and component models of the gas cooler, evaporator, compressor and expansion valve were constructed with careful consideration of the heat transfer performances. To validate the simulation model, experiments were carried out with an actual CO2 heat pump system for heating. By comparing the simulated and experimental data, the effects of the inlet water temperature and outside air temperature on the characteristics of the system were discussed. Furthermore, an analysis on the effect of a recuperator on the performance of the system was analyzed. It is shown that when the outside temperature is -20℃, the COPh is 2.25, which indicates that this system works well in low temperature, and the efficiency of system COPh is improved by 5% when recuperator is used.     

非点源污染河流水环境容量研究

为探索适合非点源污染河流水环境容量计算的模型,为水环境容量的合理利用提供科学依据,针对中国东部地区典型河流-曹娥江的污染情况,选其上游以非点源污染为主的支流进行了水环境容量研究。根据该河段的水流特性和水文、污染源的调查资料及水质实测资料,选用适当的数学模型,研究了该河段各月的水环境容量。结果表明这种方法简单、实用,适用于非点源情形下河流氨氮、总磷及CODcr的容量问题研究。     

Mathematical Model and Operation Analysis of Semi-submerged Rotary Orifice Sewage Source Heat Pump Intake Machine

To solve the flow instability and adjustment difficulty of filtering dirt-removing device in the sewage source heat pump system, which affect the efficiency of heat exchanger, semi-flooded rotary orifice sewage auto-strainer was generated. According to establishing the mathematical model, the effect is analysed of pollutant concentration and liquid level height of sewage and rotation period of orifice plate to filtered flow rate, filtered load and filtering surface block coefficient. The result shows that: in the certain condition of sewage liquid level height and orifice plate rotation period, the increase of sewage will decrease the filtered flow rate of orifice plate, and increase filtering surface block coefficient; The effect of pollutant concentration change in the sewage to orifice plate filtered flow rate could be adjusted by regulating the sewage liquid level height and orifice plate rotation period, and the moderating effect of orifice plate rotation period is better than that of sewage liquid level height.     

地源热泵技术在中国温室设施中的应用探讨

当前在中国温室设施中应用和推广地源热泵技术尚存在诸多不利因素,大大限制了该项技术在设施农业领域中的发展。为探寻合理的解决途径,对地源热泵空调系统的关键技术和其在中国的发展概况进行了相关的阐述和分析,并以中国农业大学上庄实验站已经建成使用的地下水式温室地源热泵空调系统为实例,介绍该系统的组成、工作流程、性能参数和使用情况,探讨温室地源热泵空调系统在推广和使用中可能出现的投资较高,长时间运行性能不稳定等问题,分析其原因并提出相应的对策建议。     

Analysis of the Ground Adjustment Ability of the Ground Source Heat Pump Systems in Winter

Based on an actual ground source heat pump system in hot summer and cold winter area, the system operation parameters were tested for 6 years under the state of using cooling tower for cooling in summer but the ground heat exchanger and fire pool for heating in winter. A three dimensional (3D) tube group model was established, and the thermal balance analysis and calculation of the ground temperature distribution around the ground heat exchanger were conducted by the numerical calculation. According to the comparison between the test data and the theoretical results, the influencing factors of the ground adjustment ability were obtained.     

Performonce of Fouling Fluidized-Removing and Heat Transfer Enhancement on Sewage Side of Sewage-Source Heat Pump System

High thermal resistance resulted by fouling in heat exchanger restricts the application of sewage source heat pump (SSHP) system. The fouling forming mechanism was applied with solid-liquid fluidized bed technique for fouling prevention and removing of SSHP system. Shearing stress model of solid-liquid fluidized bed heat-exchanger is analyzed, and collision stress model is modified. Preventing and removing fouling mechanisms of solid-liquid fluidized bed technique by shearing stress and collision stress was explained. An experimental study on how to solve the fouling problem (such as fouling prevention and removing, heat transfer enhancement, etc) is discussed. The results of theory and experiment show that solid-liquid fluidized bed technique can be used not only to increase convection coefficient, but also to restrict fouling growing, it can effectively solve the fouling problem in SSHP system.     

Experimental Analysis on Characteristics of Energy Storage for Defrosting of Air Source Heat Pump with Phase Change Energy Storage

The performances of energy storage modes are experimentally analyzed in the artificial environment in order to study the effect of energy storage modes for defrosting of air source heat pump with phase change energy storage. Results indicate that suction and discharge pressures are stable at 038 MPa and 165 MPa under the series energy storage mode, and suction and discharge temperatures are 6.9℃ and 75.0℃ respectively. However, the suction and discharge pressures are as low as 012 MPa and 116 MPa in parallel and single energy storage modes individually, and the discharge temperature is up to 1225℃. In addition, in series energy storage mode, the phase change material can completely change from solid to liquid in energy storage process. The temperature difference is about 18.0℃ for indoor coil, and the input power to compressor is 825W. Therefore, the system pressures and temperatures are most stable in the series energy storage mode and the time for energy storage is short, which can meet the need of defrosting energy.     

Exploration of Feasibility of Applying on Ground-Source Heat Pump in Western Region of China

The brief introduction to properly applying HVAC to the sustainable west development of China is made in this article. The advantage of GSHP, a branch of HAVC, is also presented briefly here. The emphasis is put on the fact that this system is a green one which sustainable and practicable characters. At the same time, the comparison between the key technique of GSHP and the geological condition that the system should adjust to is made, which reveals the key point of applying GSHP. According to environment condition, three types of areas are divided in the western regions of China. The feasibility of applying GSHP in each area is explained respectively and the related scheme of applying the system is also summed up.     

Analysis of Adaptability for Water Surface Heat Pumps in China Climatic Region

Based on the application characteristics of Surface Water Source Heat Pump System(WSHPs),the condition for the high efficient application of the system was expounded.Meanwhile,the distribution of water source in China Climatic Region was analyzed,and combining with the condition under which the surface water heat pump system was applied,the application feasibility of the system was explored.On the basis of the present climate division,the water source in the climate zone was analyzed comprehensively in terms of water temperature and water quality.Based on practical data,HVAC style,characteristic and condition of WSHPs,the adaptability analysis of the surface water heat pump system used in the climate zones was also given.     

黑皮冬瓜分段式变温热泵干燥工艺研究

为提升黑皮冬瓜干燥品质及降低干燥能耗,对黑皮冬瓜分段式变温热泵干燥工艺进行了研究。通过研究湿度对冬瓜干燥过程、瓜干品质及干燥能耗的影响,确定了最适相对湿度为40%和50%。根据最适湿度条件下干燥前期温度的波动情况设计了4种分段式变温干燥工艺,采用综合加权评分法对4种工艺进行比较,得到了最适分段式变温热泵干燥工艺为:温度50℃(5 h)-60℃(至结束),相对湿度50%,循环风速1.5 m/s,瓜片厚度6 mm。将热泵干燥方式与传统的电热干燥方式进行比较,发现热泵干制的瓜干品质显著优于电热干制的瓜干(P0.05),热泵恒温干燥较电热恒温干燥节能38.93%,热泵变温干燥可在进一步提升瓜干品质的同时较热泵恒温干燥节能11.25%。