This paper is based on the rainwater collection project in the retrofit of the Dongyi teaching block in Zhejiang University Xixi Campus.The analysis incorporates the local meteorological data, recycling water utilizat...This paper is based on the rainwater collection project in the retrofit of the Dongyi teaching block in Zhejiang University Xixi Campus.The analysis incorporates the local meteorological data, recycling water utilization, and precipitation adjustment.The rainwater collection system in this program also adds the condensation water from the heating, ventilation and air conditioning ( HVAC) system and the concentration from the reverse-osmosis system used for watering greens and supplying waterscapes.By calculating, the quantity of the HVAC condensation water in summer is 3.48 m3/d, and the quantity of the reverse-osmosis concentrated water is 198 to 396 L/d.This method solves the water shortage caused by high evaporation in summer and low precipitation in winter.Supported by empirical monitoring data, the proposed method significantly increases the economic efficiency of the system during the summer period.展开更多
A major part of world is facing water shortages today. While the world’s population has grown to more than 7.75 billion, the quantity of sweet water has remained the same. The ever increasing use of water by such a l...A major part of world is facing water shortages today. While the world’s population has grown to more than 7.75 billion, the quantity of sweet water has remained the same. The ever increasing use of water by such a large population has resulted in pollution of many water sources. The developing world where a large fraction of total world population is located faces water scarcity in a more severe manner than the developed world. The developed world has managed to control human population and preserve natural water resources more effectively. As a result of this and also due to stabilized population, they face lesser problems for water availability. Indian population stands at 1.386 billion as nowadays. The erratic monsoon rains over last few years have resulted in floods and subsequent water shortages in summer months in major part of the country. A similar situation is faced by many Asian and African countries. The means of recycling and using every possible source of water are always welcome in these countries. Since many of these countries lie in tropical or semitropical zone, the average relative humidity is more than 50% for most of the year. Changing life styles in these countries and spread of information technology based sectors have resulted in a growth spurt in air conditioning facilities. An air conditioner draws heat from surrounding air and cools the premises to desired temperature. During this process, a large amount of moisture in the atmosphere gets condensed and is drained out. There are no efforts made to recover this water in India and neighbouring countries. We have undertaken studies to check the quality of this water and see the feasibility of its use in a decentralized but effective manner. The results show that this water condensate from air conditioners is highly pure, substantial and available almost round the year. This can help in recovering millions of litres of good quality water daily. This water would find uses in industries, laboratories, households and farming. It would also create good business opportunities.展开更多
The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit ...The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit is about 1 kW, and the work refrigerant is R22/R407C/R410A/CO2. The MATLAB/SIMULINK software was employed to build the simulation model. The thermodynamic simulation model is significant for the optimization of parameters of the unit, such as condensation and evaporation temperature and mass flow of the sanitary hot water and size of hot water storage tank. The COP of the CCP of R410A system is about 3% - 5% higher than the CCP of the R22 system, while CCP of the R407C system is a little lower than the CCP of R22 system. And the CCP of CO2 trans-critical system has advantage in the hot supply mode. The simulation method provided a theoretical reference for developing the production of CCP with substitute refrigerant R407C/R410A/CO2.展开更多
A new type of microchannel condenser applied in the air source heat pump water heater(ASHPWH)with cyclic heating was proposed in this study.The operating performance of the ASHPWH was frst tested.Then,the structure of...A new type of microchannel condenser applied in the air source heat pump water heater(ASHPWH)with cyclic heating was proposed in this study.The operating performance of the ASHPWH was frst tested.Then,the structure of the microchannel condenser was optimized with the implement of vortex generators.Finally,a numerical model of the ASHPWH was established and the optimized microchannel condenser was studied.The experimental results showed that the average coefficient of performance(COP)of the 1HP(735 W)ASHPWH reached 3.48.In addition,the optimized microchannel condenser could be matched with a 3 HP(2430W)ASHPWH with an average heating capacity of 10.30 kW,and achieving an average COP of 4.24,14.6%higher than the limit value in the national standard.展开更多
Recycling the condensate water of the air conditioner could be explored as an alternative water source to con-tribute to building the green campus.This paper explored the condensate water production through actual mea...Recycling the condensate water of the air conditioner could be explored as an alternative water source to con-tribute to building the green campus.This paper explored the condensate water production through actual mea-surement based on a split air handling unit(SAHU)in a university building.Then,the statistical analysis was used to analyze the recycling feasibility and the impact factors of the condensate water production in 31 Chinese provincial capital cities to obtain the recycling potential map of the condensate water generated from a SAHU.Results showed that:(1)In the measurement,the amount of condensate water produced by a single split air conditioner was 1.6 kg from 12:40 to 13:40.Therefore,the daily output of condensate water of the air condi-tioner with the university operation schedule could reach 52.99 kg during the main air-conditioning season.(2)Among the 31 provincial capital cities in China,the largest condensate water outputs could be found in the Hot Summer and Warm Winter zone and the Hot Summer and Cold Winter zone,with an average monthly output of 1600 kg and 1100 kg,respectively.(3)Regression analysis showed that the dry-bulb temperature and dew point temperature of outdoor air had the highest positive and significant influence on condensate water production.The objective of this study is to provide theoretical guidance for the design and energy conservation evaluation of the feasibility of SAHU condensate water recycling in universities.展开更多
文摘This paper is based on the rainwater collection project in the retrofit of the Dongyi teaching block in Zhejiang University Xixi Campus.The analysis incorporates the local meteorological data, recycling water utilization, and precipitation adjustment.The rainwater collection system in this program also adds the condensation water from the heating, ventilation and air conditioning ( HVAC) system and the concentration from the reverse-osmosis system used for watering greens and supplying waterscapes.By calculating, the quantity of the HVAC condensation water in summer is 3.48 m3/d, and the quantity of the reverse-osmosis concentrated water is 198 to 396 L/d.This method solves the water shortage caused by high evaporation in summer and low precipitation in winter.Supported by empirical monitoring data, the proposed method significantly increases the economic efficiency of the system during the summer period.
文摘A major part of world is facing water shortages today. While the world’s population has grown to more than 7.75 billion, the quantity of sweet water has remained the same. The ever increasing use of water by such a large population has resulted in pollution of many water sources. The developing world where a large fraction of total world population is located faces water scarcity in a more severe manner than the developed world. The developed world has managed to control human population and preserve natural water resources more effectively. As a result of this and also due to stabilized population, they face lesser problems for water availability. Indian population stands at 1.386 billion as nowadays. The erratic monsoon rains over last few years have resulted in floods and subsequent water shortages in summer months in major part of the country. A similar situation is faced by many Asian and African countries. The means of recycling and using every possible source of water are always welcome in these countries. Since many of these countries lie in tropical or semitropical zone, the average relative humidity is more than 50% for most of the year. Changing life styles in these countries and spread of information technology based sectors have resulted in a growth spurt in air conditioning facilities. An air conditioner draws heat from surrounding air and cools the premises to desired temperature. During this process, a large amount of moisture in the atmosphere gets condensed and is drained out. There are no efforts made to recover this water in India and neighbouring countries. We have undertaken studies to check the quality of this water and see the feasibility of its use in a decentralized but effective manner. The results show that this water condensate from air conditioners is highly pure, substantial and available almost round the year. This can help in recovering millions of litres of good quality water daily. This water would find uses in industries, laboratories, households and farming. It would also create good business opportunities.
文摘The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit is about 1 kW, and the work refrigerant is R22/R407C/R410A/CO2. The MATLAB/SIMULINK software was employed to build the simulation model. The thermodynamic simulation model is significant for the optimization of parameters of the unit, such as condensation and evaporation temperature and mass flow of the sanitary hot water and size of hot water storage tank. The COP of the CCP of R410A system is about 3% - 5% higher than the CCP of the R22 system, while CCP of the R407C system is a little lower than the CCP of R22 system. And the CCP of CO2 trans-critical system has advantage in the hot supply mode. The simulation method provided a theoretical reference for developing the production of CCP with substitute refrigerant R407C/R410A/CO2.
基金the National Natural Science Foundation of China(No.51776117)。
文摘A new type of microchannel condenser applied in the air source heat pump water heater(ASHPWH)with cyclic heating was proposed in this study.The operating performance of the ASHPWH was frst tested.Then,the structure of the microchannel condenser was optimized with the implement of vortex generators.Finally,a numerical model of the ASHPWH was established and the optimized microchannel condenser was studied.The experimental results showed that the average coefficient of performance(COP)of the 1HP(735 W)ASHPWH reached 3.48.In addition,the optimized microchannel condenser could be matched with a 3 HP(2430W)ASHPWH with an average heating capacity of 10.30 kW,and achieving an average COP of 4.24,14.6%higher than the limit value in the national standard.
基金funded by Sichuan Agriculture University,and is supported in part by the scholarship from China Scholarship Council(CSC)under the Grant CSC 202006915024.
文摘Recycling the condensate water of the air conditioner could be explored as an alternative water source to con-tribute to building the green campus.This paper explored the condensate water production through actual mea-surement based on a split air handling unit(SAHU)in a university building.Then,the statistical analysis was used to analyze the recycling feasibility and the impact factors of the condensate water production in 31 Chinese provincial capital cities to obtain the recycling potential map of the condensate water generated from a SAHU.Results showed that:(1)In the measurement,the amount of condensate water produced by a single split air conditioner was 1.6 kg from 12:40 to 13:40.Therefore,the daily output of condensate water of the air condi-tioner with the university operation schedule could reach 52.99 kg during the main air-conditioning season.(2)Among the 31 provincial capital cities in China,the largest condensate water outputs could be found in the Hot Summer and Warm Winter zone and the Hot Summer and Cold Winter zone,with an average monthly output of 1600 kg and 1100 kg,respectively.(3)Regression analysis showed that the dry-bulb temperature and dew point temperature of outdoor air had the highest positive and significant influence on condensate water production.The objective of this study is to provide theoretical guidance for the design and energy conservation evaluation of the feasibility of SAHU condensate water recycling in universities.