Air-conditioning Refrigeration System Research Articles

Research on Vehicle Aerodynamics and Thermal Management Based on 1D and 3D Coupling Simulation

In order to ensure the full heat dissipation of heat exchangers, the opening of the grille should be large, which increases the wind drag of the whole vehicle. Most of the research on the grille only focuses on its impact on the heat dissipation of the engine compartment; there is little research on its influence on the performance of the thermal management system, because it is difficult to solve the real-time data interaction of different dimensional models. So we established the 1D and 3D strong coupling model. The biggest difference from other 1D and 3D coupling models is that we can use the interfaces reserved by the two kinds of software to realize real-time data interaction, and simultaneously analyze the 1D thermal management performance and 3D flow field and temperature field of the engine components. The coupling model is used to study three heat balance conditions. The results show that the heat-sinking capability of the cooling system is the worst under the climbing condition; and the refrigeration capacity of the air-conditioning system is the worst under the idling condition. According to the heat balance results and evaluation index priorities, we determine the simulation process. In this article, first the upper grille is gradually closed; then the flow field, temperature field and evaluation indexes are studied through the strong coupling model to obtain the analysis results of the upper grille; then based on the results, the lower grille is gradually closed, and the analysis results of the lower grille are obtained in the same way. The final simulation results show that on the premise of ensuring the performances of engine cooling system and air conditioning refrigeration system, the air drag coefficient is reduced by 17.5 counts compared with the original vehicle.

Energy-saving diagnosis model of central air-conditioning refrigeration system in large shopping mall

Aiming at the problems of extensive management and energy waste in the operation of shopping malls, this paper proposed a shopping mall building energy-saving diagnosis model based on an improved PSO-SVM neural network. Firstly, the operation data with good energy-saving characteristics were selected from the collected historical data of energy consumption by clustering algorithm as the data basis for the establishment of the model. Secondly, the Adaboost algorithm was used to optimize the PSO-SVM neural network to complete the model construction, and the energy-saving data was used to complete the training of the model. Finally, the judgment criteria for abnormal energy consumption were established, and the energy consumption situation at the current moment was diagnosed by using the trained energy-saving diagnosis model. The abnormal judgment criteria of energy consumption were used to analyze the diagnostic results, and the energy-saving diagnosis process was completed, which was verified by case analysis. Through case analysis and verification, the energy-saving rate of the energy-saving diagnosis model established in this paper has been increased from -1.1% to 11.9%, and the problem moments generated during the operation of air conditioning in shopping malls have been successfully diagnosed. The model established in this paper can not only find out the unreasonable conditions in the operation of the air-conditioning system, but also provide a reference for building energy-saving management and operation.

Cloud computing environment of waste heat driven air conditioning refrigeration system parameters optimization research

In view of the poor performance of waste heat driven air conditioning refrigeration system parameter optimization problems such as study, through to the air conditioning heat driving power and refrigerating capacity parameters calculation, and set up according to the results of the calculation of waste heat driven air conditioning cooling parameters, after the complete parameter Settings, in order to guarantee the software and hardware of the air conditioning refrigeration system operation parameters for testing, according to the test results of waste heat driven air conditioning refrigerating system parameter adjustment and control, finally realize the cloud computing environment of waste heat driven air conditioning refrigeration system parameters optimization. Finally, it is confirmed by experiments that the parameter optimization method of waste heat driven air-conditioning and refrigeration system in the cloud computing environment has better optimization effect and can ensure the stable operation of the air-conditioning and refrigeration system.

Fault diagnosis of air-conditioning refrigeration system based on sparse autoencoder

Abstract To overcome the drawbacks of using supervised learning to extract fault features for classification and low nonlinearity of the features in most of current fault diagnosis of air-conditioning refrigeration system, sparse autoencoder (SAE) is presented to extract fault features that are used as the input to the classifier and to achieve fault diagnosis for air-conditioning refrigeration system. The SAE structure is tuned by adjusting the number of hidden layers and nodes to build the optimal model, which is compared with the fault diagnosis model based on support vector machine. Results indicate that the indexes of the model combined with SAE, such as accuracy, precision and recall, are all improved, especially for the faults with high complexity. Besides, SAE shows high generalization ability with small-scale sample data and high efficiency with large-scale data. Obviously, the use of SAE can effectively optimize the diagnosis performance of the classifier.

Design and Modeling of One Refrigeration Ton Solar Assisted Adsorption Air Conditioning System

The modeling of the performance of a one refrigeration ton (RT) solar assisted adsorption air-conditioning refrigeration system using activated carbon fiber/ethanol as the adsorbent/adsorbate pair has been undertaken in this study. The effects of hot water, cooling water, chilled water inlet temperatures, and hot water and chilled water flow rates were taken into consideration in the optimization of the system and in the design of the condenser, evaporator, and hot water storage tank. The study includes analysis of the weather data and its effect on both the adsorption system and the cooling load. This is then followed by estimation of the cooling capacity and coefficient of performance (COP) of the adsorption system as a function of the input parameters. The results of the model will be compared to experimental data in a next step.

Reliability Analysis of Air-conditioning Refrigeration System for Chery A3 Automobile

Reliability Analysis of Air-conditioning Refrigeration System for Chery A3 Automobile

Fault Prediction in Air-Conditioning Refrigeration System by Wavelet Transform

A good deal of electricity consumption can be attributed to air-conditioning refrigeration systems. The percentage can be significantly higher if a cooling system is operating at low performance levels due to the presence of faults. The wavelet transform moves data from a time domain to a frequency domain with the wavelet as the basic function giving the localized features of the original signal in the fault detection. It is well known for its capability of treating the transient or time-related varying signals. The fault of heat load increase of the air-conditioning room can be predicted by wavelet transform through the test. Fault prediction in air-conditioning refrigeration system by wavelet transform can avoid defects of the conventional methods.

Study on the Hybrid Liquid Desiccant Evaporative Cooling Air-Conditioning Refrigeration Circulation System

This article presents a new hybrid evaporative cooling air-conditioning refrigeration system using two-stage liquid desiccant, and carries off the theoretical study on it. Compared with the conventional liquid desiccant air-conditioning refrigeration system, the new system adopts direct mixing heat transfer technology and evaporative cooling technology instead of water-cooled or air-cooled technology. Thus the cooling water usage is reduced. Using the two-stage adiabatic absorber and using refrigerant rather than water as the cooling medium of desiccant solution, the pressure difference of mass transfer is increased. Compared with the conventional system, the heat of regenerating solution is decreased because the mass ratio of air to desiccant solution is increased which gives rise to the decline of solution's mass rate. The results of theoretical calculation show that the new system has the better performance in power consumption, usage of water and equivalent coefficient of performance than the conventional system.

Analysis of Energy Factor Effectiveness in Air-Conditioning Refrigeration System

This paper deals with the energy-saving product design involving the product energy property into design process. On the basis of the energy factors concepts, the paper analyzes the extraction process and energy effectiveness model of energy factors. To study the air-conditioning refrigeration system, the paper establishes the energy information model, recognizes the crucial and controllable energy element and extracts the energy factor set C = {compressor volumetric efficiency λ, motor efficiency ηd, power frequency fd, heat transfer performance coefficient φ, finned lateral general area Ao}. Then it makes a further decomposition of coupling energy factors λ, φ and finds out the corresponding design parameter. In the end, the paper maps the energy factors and design parameter into design process, establishes the energy effectiveness model and presents several measurers for decreasing the energy consumption during the actual use of air-conditioner.