Design and Construction of an Air Conditioning System Employing a Ground Source Heat Pump Combined with a Radiant Floor

The air conditioning system using a ground source heat pump(GSHP) combined with a radiant floor integrates the advantages of both types,giving such a system large potential for popularization.After experimenting with one house's hybrid system,the design processes and construction methods for such a system can be summarized.In the experiment,different terminal devices were used to adopt varying winter and summer climatic conditions.It is suggested that the constructors should make good use of resources and waste water during the construction phase.The experimental results show that this hybrid system runs steadily and it supports a better temperature field to meet the requirement for the human comfort.Finally,a hybrid system managment strategy is suggested.     

Research on Calculation of the Automobile Air Conditioner's Cooling Load

In this paper a nonsteady heat flux equation for car body is established and the formulationof transmission function coeficient of the cooling load is derived. The composition of the automobile airconditioner's cooling load has been analysed and a computer program for calculating the cooling loadhas been compiled, It has proved to be exact from the example, So these results are of practical value.     

不同中心集风管形式对浅圆仓降温通风效果的模拟研究

在CFD数值模拟技术的基础上,对浅圆仓不同中心集风管形式下的径向通风降温数值模拟结果分析,并进行对比以评判优劣。研究的粮食种类为大豆,数值模拟了四种变径形式的中心集风管顶部,或开孔或不流通,共八种情况的通风条件下,粮堆内部温度分布和气流组织情况,将八种情况下的数值模拟结果对比,分析其通风均匀性和通风降温速率。研究发现,集风管高度与粮面平齐且上粗下细时有较为明显的优越性,通风均匀性较好。研究结果对浅圆仓仓储大豆通风降温方式的选择提供了理论依据。     

Experimental Comparison of Low-temperature Hydraulic Heating Floor and Heat Pump Air-conditioning

In this paper the low-temperature hydraulic floor heating system of a residence in Chongqing was tested. The influence of this system and the heat pump air conditioning system on indoor thermal comfort and operation cost was analyzed and compared. The effect of heat dissipation by radiation and convention of the floor was analyzed. It shows the feasibility and advantage of floor heating system in Yangtse River Region.     

Design of Cooling/Heating Floor AC Systems in Residential Buildings

This paper puts forward a new way in air_conditioning,which combines the fresh_air supply unit and such floor radiation system for the dehumidication and cooling in summer or heating in winter. By analyzing its advantages and limitations, it is found that this so called Cooling/Heating Floor AC System can improve the IAQ of residential building while keep high efficiency quality. It is also recommended that an methodology for the HVAC system designing,which will ensure the reduction of energy cost of users.     

Predictive Model of Performance of Metal-packed Evaporative Air Conditioning System

Based on characters of Artificial Neural Network(ANN) such as non-liner mapping,self-learning,the ANN model was set up to predict the relationship between effective factors and performance of metal-packed evaporative air conditioning system.In order to reflect the performance of the predictive model,experimental data were used to test and verify the model.The outcome of the ANN model is in good agreement with experimental data and relative difference is within 6 percent.So it is feasible to predict the performance of metal-packed evaporative air conditioning system.     

Design and Analysis of the Air Flow and Distribution of Laminated Air Conditioning in Summer in the Powerhouse of Sanxia Hydropower Station

Around the design of air flow and distribution about the laminated air conditioning in summer in the powerhouse of Sanxia hydropower station, the system division, air flow pattern, air supply state and volume etc have been analyzed separately. Based on the existing domestic achievements, the relative calculation model has been established and the application method has been explored. From this the program named as AFDC/LACS has been compiled with language FORTRAN77 and the calculation on the airflow and distribution of the place mentioned above has been done with several design conditions. Thus some batches of the technical parameters have been provided to plan the test conditions in the heat simulated test..     

Hydraulic Characteristics and Energy Efficiency of An Air Conditioning Chilled Water System With Primary Pumps

The hydraulic characteristics and energy-saving performance of a chilled water system with primary pumps is analyzed. It is proved that the hydraulic characteristics of the system with terminal of the air conditioners tends to large temperature differences and small flow rate, while the hydraulic characteristics of the system with terminal of the combination of fan coil units and air conditioners tends to large flow rate and small temperature differences. When the cooling load is reduced, in order to ensure the energy-saving performance of the primary pump system, the fixed chilled water flow is required. If the fixed water flow system is adopted to regulate the outlet water temperature,the bypass water flow rate should be decreased as much as possible. If the pump frequency regulation is selected, and the proportion of energy consumption of the pump accounts for 30% of the total at the same time, the more the system’s hydraulic characteristics approaches that of air conditioners, the higher the energy-saving rate will be, which could be markedly greater than 10%. By regulating the water temperature and cold water quantity, over flow of chilled water still exists. Therefore, bypass water flow should be provided. And the bypass pipe diameter is determined respectively by the water flows which are 1.2 ~ 1.8 or 0.2 ~ 1.0 times larger than that of a single chiller when the pump works in frequency conversion and constant frequency.     

Load Prediction with Neural Network Method and Operation Optimization of Ice Storage Air Conditioning System

This paper presents some common control strategy of ice storage air conditioning system. It is suggested that the optimization on ice storage air conditioning system should be based on accurate load prediction and the artificial neural network (ANN) modeling for load prediction was presented.     

Model Experiment and Primary Research of Laminated Air Conditioning in the Powerhouse of Three-Gorges Hydropower Station in Summer

In this paper, the model experiment of laminated air conditioning in the powerhouse of Three-Gorges Hydropower Station was introduced. To assure the effect of air conditioning, the influence of different roof temperature, air supply velocity and Ar number on air distribution was analyzed and studied. Some conclusions have been drawn.     

Analysis and Applicati on High- Efficacy Saving Energy Technique of Central Air - Conditioning System

Aimins at the state that present central air- conditioning systems performance in high ineffective energy consumption, this paper studies the reasons of ineffective energy consumption and the key technique to solove the problem. A set of energe saving device for central air - conditioning systems is developed. A system dynamical mathematical model is established in theory, and an optimal performance pattern is fired. The central air - conditioning system can work in the optimal pattern with effective comfortability and saving energy by using. The device may save power rate to 22.6% by survey and may have broad market prospect in the southern area.     

Effects of Air Temperature and Humidity on Particle Deposition in a Ventilation Duct

Particle deposition in a fully developed turbulent flow of ventilation duct with a rectangular cross section of 0.3 m×0.2 m and 3 m in length was investigated. The effects of thermophoretic force and air humidity were also considered. Trajectories of 3 000 particles were tracked on the basis of the random walk model from Lagrangian approach. The profile of dimensionless deposition velocity with relaxation time was achieved and the comparison with the previous studies was made with particle size range of 0.01 50 μm and air flow velocity of 5 m/s. It is found that the trend of dimensionless deposition velocity is in agreement with the previous studies and the profile of dimensionless deposition velocity showed a V shaped curve. The effects of temperature and air humidity were also investigated with particle size of 1 μm. Thermophoretic force caused by temperature gradient between air flow and wall surface accelerated particle deposition. Meanwhile, it is also found that the deposition velocity increases with the increase of air relative humidity.     

A Theoretical Study on Thermal Dynamics Model and the Dehumidification Capacity of Hybrid Desiccant Cooling System with Condensation Heat Recovery

The structure and energy conservation characteristics of hybrid desiccant cooling system with condensation heat recovery are introduced briefly. Based on the first and second law of thermodynamics, a system thermodynamic model is established and the solution process given in a diagram. The dehumidification capacity is calculated under different exergy efficiency and indoor sensible heat conditions. The calculation results show that the desiccant wheel barely can compensate for the humidity load of outdoor air under with a ventilation rate of providing fresh air once per hour; when the fresh air rate of ventilation is limited to 0.5 times per hour, however, the desiccant wheel possess sufficient capacity under relatively large wheel exergy efficiency and high sensible heat load.