Advanced Materials Research Vols. 516-517

Abstract: To analyze the accuracy in the volume measurement of vertical tank with flowmeter, experiment based on volume measurement device of standard flowmeter method with different flowmeter is made in this paper. The capacity values of different liquid level in tank which are used to fitting and correcting the actual results of continuous measurement are calibrated by standard flowmeter and level gauge. Fitting coefficient can be used to analyze the accuracy of other measurement. Experiment results show that it is feasible to measure the capacity of vertical tank by standard flowmeter with high measure accuracy and small measure error.

Abstract: A new formulation, that employs both two-stage dehumidification and intercooler to effectively enhance system performance is proposed and investigated experimentally. The paper briefly describes desiccant wheel including the coupled fundamental principle and overall structure originally. An experimental setup is subsequently designed and built to evaluate the system performance under various operation conditions. The effects of different fresh air intake temperature at various regeneration temperature under given conditions are numerically analyzed and explained. Finally, results of a test-case are presented, indicating compared with the common single-stage system, an increase in humidity removal. Meanwhile, increasing regeneration air volume and temperature can significantly improve the dehumidification ability for sorbent materials and coefficient of performance of the system respectively, as well as save indirectly electric energy consumption, which is derived from the energy-intensive regeneration blower.

Abstract: In this paper, a finite element model of an automotive air cleaner is established. Through the free modal analysis of this FEA model, combined with Modal Testing which modified the FEA model, different order modal frequency and modal characteristics are acquired, which supply the reference standard for dynamic design. According to the analysis, the local unreasonable structure will be optimized.

Abstract: A novel experimental apparatus of a liquid desiccant air-conditioning system was introduced. The system differed from similar researches in that it could handle the total load of the conditioned space without any refrigeration equipment and it worked in ventilation mode, which could greatly improve the indoor air quality. The schematic diagram of the system was presented and circulating processes of air, water and lithium chloride solution in the system were introduced. The definition of thermal coefficient of performance (TCOP) for the system was introduced and main operating parameters that could affect TCOP were analyzed. The tested TCOP of the system was 0.72～0.98 in summer and 0.30～0.51 in autumn, which showed that liquid discussant air conditioning system was especially suitable for hot and humid conditions.

Abstract: An auto cascade refrigerating cycle system was built up in the laboratory. By changing the parameters of the operation process, the law of the operation and the effect on performance of the system were studied. When the extrinsic parameters changed, the performances of the system were measured. The paper analyzed that the evaporation temperature and the temperature of the inlet of the cooling water affect on the efficiency of the system and the pressure rate. The result shows that when the temperature of the cooling water is given, the COP of the system goes down with the decrease of the evaporation temperature. And when the evaporation temperature is given, the COP of system goes down with the increase of the condensate temperature. The pressure rate increases when the temperature of the cooling water gets higher. When both the evaporation temperature and the temperature of the cooling water are given, the COP of a R22/R23 system is higher than that of an R134a/R23 system.

Abstract: The quantity of the cold store in our country has been rapidly rising since the 1990s, however, the flow field in the cold store is difficult to obtain accurately by experiments. With reference to the experiences in previous numerical simulations in this paper, CFD is used for analyzing two forms of return air in the cold store with the Finite Volume Methods and the SIMPLE Revised. As a result, Combining with the non-equilibrium wall function, it is found that taking the way of return air on both sides of the fan is more reasonable and the cooling consumption of the empty cold store can be saved before the products enter the cold store. Furthermore, the numerical simulation results can provide reference for choosing fans in the small cold store.

Abstract: Chongqing weather conditions as the representative, energy simulation software DesT-c Chongqing office building energy simulation analysis, simulated natural building under different ventilation conditions at room temperature, the energy consumption of building cooling load and air-conditioning system changes, with an emphasis on energy-saving effect of the night ventilation; The study showed that in Chongqing reasonable use of ventilation reduce building natural room temperature to a certain extent; Sensitive indicators of building air conditioning energy consumption than the heating energy consumption of ventilation was significantly; Night ventilation when the number of ventilators is less than 5 times / h, the energy saving effect is very significant.

Abstract: To analyze the evaporation characteristics of single water droplet in the air with low temperature and low humidity, a theoretical model of droplet heat and mass transfer was proposed. The evaporation process of droplet in supercooled stage was simulated through theoretical model, results from modeling basically tallies with experiment, thus it is feasible to predict the evaporation characteristics of water droplet with smaller diameter by the mathematical model. The evaporative supercooled process of droplet in ice-slurry production system was calculated using the above-mentioned theoretical model. Results show that both the smaller droplet diameter and the lower droplet initial temperature can increase the cooling rate of water, in addition, the cooling rate can also be increased with the increase of air velocity or with the decrease of air temperature. Futhermore, droplet with lower supercooled temperature can be obtained with lower the air temperature. The initial droplet diameter less than 100µm can not only greatly improve the supercooling degree when the evaporative time of droplet is same, but also decrease the height of the ice making chamber.

Abstract: Depending on the project which will use the cooling system Combined with evaporative cooling chillers and mechanical chiller in yulin, the evaporative cooling chillers and mechanical chiller of water system were respectively analyzed in three different forms in this article. Starting from the different process of three different forms in Psychrometrics and the different running time, three different form of water system had been preliminary budgeted. It can be known that the economy of configuration scheme of evaporative cooling technology and mechanical refrigeration technology.

Abstract: The application of natural refrigerant CO₂ is of great significance to reduce the greenhouse effect and ozone depletion. Transcritical CO₂ refrigeration cycle is presently an important aspect of natural refrigerant alternatives research. In this paper, the transcritical CO₂ refrigeration cycle system is experimentally studied, effect on performance of heat rejection pressure, gas-cooler outlet temperature and evaporation temperature is analyzed. The experimental results show that there is an optimum high pressure to achieve the maximum COP, the evaporation temperature and gas-cooler exit temperature have great impact on the COP. Increase of gas-cooler outlet temperature led to a rapid increase in the optimal high pressure, but effect of evaporation temperature is not obvious. So in order to obtain the optimum performance, the influence of heat rejection pressure, evaporating temperature and gas-cooler outlet temperature should be considered during the designing and operating CO₂ refrigeration cycle system.