The relevant standard requirements both in domestic and abroad provide the basis for designing air-conditioning system of railway vehicles present. However, there are great differences in the fresh air volume indicato...The relevant standard requirements both in domestic and abroad provide the basis for designing air-conditioning system of railway vehicles present. However, there are great differences in the fresh air volume indicators among different standards requirements, and the requirements of each vehicle procurement contracts are also different. The design of air-conditioning become difficult above these. In this paper, the fresh air volume of different type railway vehicles is analyzed from health and equipment electricity consumption according to the railway vehicles air-conditioning system standard requirements in domestic and abroad. Some advises for designing air-conditioning system of railway vehicles through the fresh air volume calculation and comparison for domestic air-conditioning system of railway vehicles was provided.展开更多
With the development of the technology of the Internet of Things,more and more operational data can be collected from air conditioning systems.Unfortunately,the most of existing air conditioning controllers mainly pro...With the development of the technology of the Internet of Things,more and more operational data can be collected from air conditioning systems.Unfortunately,the most of existing air conditioning controllers mainly provide controlling functions more than storing,processing or computing the measured data.This study develops an online fault detection configuration on the equipment side of air conditioning systems to realize these functions.Modbus communication is served to collect real-time operational data.The calculating programs are embedded to identify whether the measured signals exceed their limits or not,and to detect if sensor reading is frozen and other faults in relation to the operational performance are generated or not.The online fault detection configuration is tested on an actual variable-air-volume(VAV)air handling unit(AHU).The results show that the time ratio of fault detection exceeds 95.00%,which means that the configuration exhibits an acceptable fault detection effect.展开更多
Variable air volume(VAV)air-conditioning(AC)systems are widely employed to achieve a comfortable room thermal and humid environment depending on its better regulation performance and energy efficiency.In the single co...Variable air volume(VAV)air-conditioning(AC)systems are widely employed to achieve a comfortable room thermal and humid environment depending on its better regulation performance and energy efficiency.In the single coil VAV AC system,conventional proportional-integral(PI)control algorithm is usually adopted to track the set-points of the room temperature and humidity by regulating the supply air flow rate and the chilled water flow rate,respectively.However,the control performance is usually not good due to the high coupling of the heat and mass transfer in the air-handling unit(AHU).A model-based control method is developed to realize the decoupling control of the room temperature and humidity according to the bilinear characteristics of the temperature and humidity variation.In this control method,a bilinear room temperature controller is used to track the room temperature set-point based on the real-time cooling load,while a room humidity controller is used to track the room humidity set-point depending on the real-time humidity load.The control performance was validated in a simulated VAV AC system.The test results show that comparing with the conventional PI control,the room temperature and humidity are controlled much more robustly and accurately by using the proposed model-based control method.展开更多
文摘The relevant standard requirements both in domestic and abroad provide the basis for designing air-conditioning system of railway vehicles present. However, there are great differences in the fresh air volume indicators among different standards requirements, and the requirements of each vehicle procurement contracts are also different. The design of air-conditioning become difficult above these. In this paper, the fresh air volume of different type railway vehicles is analyzed from health and equipment electricity consumption according to the railway vehicles air-conditioning system standard requirements in domestic and abroad. Some advises for designing air-conditioning system of railway vehicles through the fresh air volume calculation and comparison for domestic air-conditioning system of railway vehicles was provided.
基金Research Project of China Ship Development and Design Center,Wuhan,China。
文摘With the development of the technology of the Internet of Things,more and more operational data can be collected from air conditioning systems.Unfortunately,the most of existing air conditioning controllers mainly provide controlling functions more than storing,processing or computing the measured data.This study develops an online fault detection configuration on the equipment side of air conditioning systems to realize these functions.Modbus communication is served to collect real-time operational data.The calculating programs are embedded to identify whether the measured signals exceed their limits or not,and to detect if sensor reading is frozen and other faults in relation to the operational performance are generated or not.The online fault detection configuration is tested on an actual variable-air-volume(VAV)air handling unit(AHU).The results show that the time ratio of fault detection exceeds 95.00%,which means that the configuration exhibits an acceptable fault detection effect.
基金This work presented in this paper is financially supported by a grant(No.51678263)of National Science Foundation of China.
文摘Variable air volume(VAV)air-conditioning(AC)systems are widely employed to achieve a comfortable room thermal and humid environment depending on its better regulation performance and energy efficiency.In the single coil VAV AC system,conventional proportional-integral(PI)control algorithm is usually adopted to track the set-points of the room temperature and humidity by regulating the supply air flow rate and the chilled water flow rate,respectively.However,the control performance is usually not good due to the high coupling of the heat and mass transfer in the air-handling unit(AHU).A model-based control method is developed to realize the decoupling control of the room temperature and humidity according to the bilinear characteristics of the temperature and humidity variation.In this control method,a bilinear room temperature controller is used to track the room temperature set-point based on the real-time cooling load,while a room humidity controller is used to track the room humidity set-point depending on the real-time humidity load.The control performance was validated in a simulated VAV AC system.The test results show that comparing with the conventional PI control,the room temperature and humidity are controlled much more robustly and accurately by using the proposed model-based control method.
