A water loop variable refrigerant flow（WLVRF）air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a va...A water loop variable refrigerant flow（WLVRF）air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a variable refrigerant flow（VRF）air-conditioning unit,a water loop and an air source heat pump.The water loop transports energy among different regions in the buildings instead of refrigerant pipes,decreasing the scale of the VRF air-conditioning unit and improving the performance.Previous models for refrigerants and building loads are cited in this investigation.Mathematical models of major equipment and other elements of the system are established using the lumped parameter method based on the DATAFIT software and the MATLAB software.The performance of the WLVRF system is simulated.The initial investments and the running costs are calculated based on the results of market research.Finally,a contrast is carried out between the WLVRF system and the traditional VRF system.The results show that the WLVRF system has a better working condition and lower running costs than the traditional VRF system.展开更多
This paper presented an entropy evaluation method for the influences of condense heat recovery system on the environment.Aiming at the damage of the condense heat to the environment,an entropy of resource loss and an ...This paper presented an entropy evaluation method for the influences of condense heat recovery system on the environment.Aiming at the damage of the condense heat to the environment,an entropy of resource loss and an emission entropy from the condense heat recovery system in the air conditioning refrigerating machine were introduced.For the evaluation of the entropies,we developed a new algorithm for the parameter identification,called the composite influence coefficient,based on the Least Squares Support Vector Machine method.By simulation,the numerical experiments shows that the Least Squares Support Vector Machine method is one of the powerful methods for the parameter identification to compute the damage entropy of the condense heat,with the largest training error being-0.025(the relative error being-3.56%),and the biggest test error being 0.015(the relative error being 2.5%).展开更多
The evaporative cooling,which assists the refrigeration machinery air-conditioning systems test-rig,has been designed.Its structure and working principle were described,and the performance test was conducted and analy...The evaporative cooling,which assists the refrigeration machinery air-conditioning systems test-rig,has been designed.Its structure and working principle were described,and the performance test was conducted and analyzed.The test shows that making full use of the evaporative cooling "free cooling" in Spring and Autumn seasons can fully meet the requirements of air-conditioned comfort through the switch of the function in different seasons.Taking into account the evaporative cooling fan and pump energy consumption,compared with the traditional mechanical refrigeration system,more than 80 percent of energy can be saved,and the energy efficiency ratio of the Unit(EER)is as high as 7.63.Using the two stages of indirect evaporative cooling to pre-cool the new wind in summer,under the conditions of the same air supply temperature requirements,0.83 kg/s chilled water saved can be equivalent to the traditional mechanical refrigeration system,and when the new wind ratio up to 50 percent,more than 10 percent load was reduced in mechanical refrigeration system.The overall EER increased about 35 percent.展开更多
Different from the traditional hydraulic oil cooling method,a new type of constant temperature oil tank cooling system based on semiconductor refrigeration technology is designed. This paper studies the principle of s...Different from the traditional hydraulic oil cooling method,a new type of constant temperature oil tank cooling system based on semiconductor refrigeration technology is designed. This paper studies the principle of semiconductor refrigeration and establishes a heat transfer model. Semiconductor cooler on piping refrigeration is simulated,and influence of the parameters on the outlet temperature,such as pipe pressure difference of inlet and outlet,pipe length,pipe radius,are gotten,and then hydraulic tank semiconductor refrigeration system is proposed. The semiconductor refrigeration system can control temperature at 37 ± 1°C.展开更多
This paper analyzes the status and the development trend of refrigerator fresh-keeping technologies domestically and internationally, introduces several popular fresh-keeping technologies, elaborates on the principles...This paper analyzes the status and the development trend of refrigerator fresh-keeping technologies domestically and internationally, introduces several popular fresh-keeping technologies, elaborates on the principles and characteristics of several fresh-keeping technologies, and put forth that the future research should be focused on the different needs of customers.展开更多
An adsorption refrigeration system can be driven by low grade heat and uses natural refrigerant with the advantage of reducing the greenhouse gases emission.However,one of the weaknesses is its low efficiency and more...An adsorption refrigeration system can be driven by low grade heat and uses natural refrigerant with the advantage of reducing the greenhouse gases emission.However,one of the weaknesses is its low efficiency and more importantly its high cost.The recovery of internal waste heat becomes therefore very important in order to improve the coefficient of performance(COP).Analysis based on pinch technology can be helpful to optimal heat recovery operation.In this paper,temperature-heat diagrams and problem tables for adsorption refrigeration systems are proposed and analyzed using Pinch Technology.The results show that pinch point is located between beds and the main waste heat needs to be recovered between beds.Dynamic characteristic(time factor)of adsorption refrigeration system is the main resistance for heat recovery.The effect of pinch point temperature difference on the system COP is not distinct.Furthermore,when the driving temperature is 90°C,the COP of adsorption refrigeration via optimization of pinch analysis is 0.73 which is fairly comparable to Li Br-water absorption refrigeration system.Pinch Technology can be adopted in different types of adsorption refrigeration systems(two-bed,four-bed,mass recovery,et al.).展开更多
Refrigerants used in refrigerators are an important source of ozone depleting substances released into the atmosphere, and can have a significantly negative effect on the hole in the ozone layer. But most emission of ...Refrigerants used in refrigerators are an important source of ozone depleting substances released into the atmosphere, and can have a significantly negative effect on the hole in the ozone layer. But most emission of refrigerants is man-made, unrea-sonable and needless. Since in most emission cases the refrigerants are contained in the refrigerators, we can retrieve them by some technique that changes the 'manual emission' into manual retriev-ing. To promote the retrieval action and diminish the pollution, society can use economic, administrative and technical counter-measures, which can create a 'good-cycle' both 'harnessing pollu-tion and earning income simultaneously', reinforce the motive of retrieving, and retrieve most proportion of refrigerants used by all refrigerators. This 'good-cycle' method can be easily promoted, and also a valuable way to promote other forms of environmental protection. The three countermeasures have almost no social cost, even no cost at all.展开更多
文摘A water loop variable refrigerant flow（WLVRF）air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a variable refrigerant flow（VRF）air-conditioning unit,a water loop and an air source heat pump.The water loop transports energy among different regions in the buildings instead of refrigerant pipes,decreasing the scale of the VRF air-conditioning unit and improving the performance.Previous models for refrigerants and building loads are cited in this investigation.Mathematical models of major equipment and other elements of the system are established using the lumped parameter method based on the DATAFIT software and the MATLAB software.The performance of the WLVRF system is simulated.The initial investments and the running costs are calculated based on the results of market research.Finally,a contrast is carried out between the WLVRF system and the traditional VRF system.The results show that the WLVRF system has a better working condition and lower running costs than the traditional VRF system.
基金Supported by Program of Science and Technology of Hunan Province(2007FJ2006)Project the Program of Science and Tech-nology of Hunan Province(2007TP4030)Hunan Provincial Natural Science Foundation of China(08JJ3093)
文摘This paper presented an entropy evaluation method for the influences of condense heat recovery system on the environment.Aiming at the damage of the condense heat to the environment,an entropy of resource loss and an emission entropy from the condense heat recovery system in the air conditioning refrigerating machine were introduced.For the evaluation of the entropies,we developed a new algorithm for the parameter identification,called the composite influence coefficient,based on the Least Squares Support Vector Machine method.By simulation,the numerical experiments shows that the Least Squares Support Vector Machine method is one of the powerful methods for the parameter identification to compute the damage entropy of the condense heat,with the largest training error being-0.025(the relative error being-3.56%),and the biggest test error being 0.015(the relative error being 2.5%).
基金Xi'an Polytechnic University Graduate Innovational Foundation(chx080608)
文摘The evaporative cooling,which assists the refrigeration machinery air-conditioning systems test-rig,has been designed.Its structure and working principle were described,and the performance test was conducted and analyzed.The test shows that making full use of the evaporative cooling "free cooling" in Spring and Autumn seasons can fully meet the requirements of air-conditioned comfort through the switch of the function in different seasons.Taking into account the evaporative cooling fan and pump energy consumption,compared with the traditional mechanical refrigeration system,more than 80 percent of energy can be saved,and the energy efficiency ratio of the Unit(EER)is as high as 7.63.Using the two stages of indirect evaporative cooling to pre-cool the new wind in summer,under the conditions of the same air supply temperature requirements,0.83 kg/s chilled water saved can be equivalent to the traditional mechanical refrigeration system,and when the new wind ratio up to 50 percent,more than 10 percent load was reduced in mechanical refrigeration system.The overall EER increased about 35 percent.
基金Supported by the National Natural Science Foundation of China(No.51175448,51405424)
文摘Different from the traditional hydraulic oil cooling method,a new type of constant temperature oil tank cooling system based on semiconductor refrigeration technology is designed. This paper studies the principle of semiconductor refrigeration and establishes a heat transfer model. Semiconductor cooler on piping refrigeration is simulated,and influence of the parameters on the outlet temperature,such as pipe pressure difference of inlet and outlet,pipe length,pipe radius,are gotten,and then hydraulic tank semiconductor refrigeration system is proposed. The semiconductor refrigeration system can control temperature at 37 ± 1°C.
文摘This paper analyzes the status and the development trend of refrigerator fresh-keeping technologies domestically and internationally, introduces several popular fresh-keeping technologies, elaborates on the principles and characteristics of several fresh-keeping technologies, and put forth that the future research should be focused on the different needs of customers.
基金supported by the National Natural Science Foundation of China(Grant No.51906136)the Institute of Advanced Studies(IAS)of the University of Warwick in the UK(Grant No C5E3X56470T)Shanghai Sailing Program(Grant No.19YF1423100)。
文摘An adsorption refrigeration system can be driven by low grade heat and uses natural refrigerant with the advantage of reducing the greenhouse gases emission.However,one of the weaknesses is its low efficiency and more importantly its high cost.The recovery of internal waste heat becomes therefore very important in order to improve the coefficient of performance(COP).Analysis based on pinch technology can be helpful to optimal heat recovery operation.In this paper,temperature-heat diagrams and problem tables for adsorption refrigeration systems are proposed and analyzed using Pinch Technology.The results show that pinch point is located between beds and the main waste heat needs to be recovered between beds.Dynamic characteristic(time factor)of adsorption refrigeration system is the main resistance for heat recovery.The effect of pinch point temperature difference on the system COP is not distinct.Furthermore,when the driving temperature is 90°C,the COP of adsorption refrigeration via optimization of pinch analysis is 0.73 which is fairly comparable to Li Br-water absorption refrigeration system.Pinch Technology can be adopted in different types of adsorption refrigeration systems(two-bed,four-bed,mass recovery,et al.).
基金supported by the Sci-ence and Technology Bureau of Nangping city,Fujian,China(Grant No.N2006Z01-4)
文摘Refrigerants used in refrigerators are an important source of ozone depleting substances released into the atmosphere, and can have a significantly negative effect on the hole in the ozone layer. But most emission of refrigerants is man-made, unrea-sonable and needless. Since in most emission cases the refrigerants are contained in the refrigerators, we can retrieve them by some technique that changes the 'manual emission' into manual retriev-ing. To promote the retrieval action and diminish the pollution, society can use economic, administrative and technical counter-measures, which can create a 'good-cycle' both 'harnessing pollu-tion and earning income simultaneously', reinforce the motive of retrieving, and retrieve most proportion of refrigerants used by all refrigerators. This 'good-cycle' method can be easily promoted, and also a valuable way to promote other forms of environmental protection. The three countermeasures have almost no social cost, even no cost at all.
