Study On The Working Characteristics Of A New Condensation Dehumidification Air Conditioning System

A new condensation dehumidification air conditioning system and a full explanation of its operating principle are presented in this paper.The system uses fresh air treated by low temperature chilled water to bear the latent heat load,return air treated by high temperature chilled water to bear the sensible heat load,which can achieve the use of energy cascade,make high and low grade energy be reasonably allocated and applied.The new air conditioning system can achieve the indoor operation in dry conditions and create a good indoor sanitation environment.The numerical calculation method is used to calculate the applicable range of the new system and the performance coefficient under each conditions.The results are presented as follows:If the indoor heat and moisture ratio is small,in order to meet the dehumidification requirements the cold water need to reduce its temperature and the fresh air ratio need to be greater.When the temperature of low temperature chilled water is determined,the indoor heat and moisture ratio has a minimum,the actual heat and moisture ratio must be not less than the minimum can the new system achieve the required air treatment process.Lower the cold water temperature is,the smaller the indoor heat and moisture ratio can achieve,the wider scope of the system will apply.When the dehumidification fresh air ratio is more than 10%,the coefficient of performance increases with the increasing of indoor heat and humidity ratio.At the same time,the higher the indoor temperature,the higher the relative humidity,the lower the low temperature chilled water temperature,the smaller the outdoor air enthalpy,the larger the coefficient of performance will be.After keeping 10% minimum fresh air ratio,the system performance coefficient will have small changes.Compared to the secondary air conditioning system,the system performance ratio is increased by(17.2~25)%.Which is(61.7~119)% compared to the primary return air conditioning system with the condensation heat reheating.Compared with the primary return air conditioning system with electric reheating,the system performance ratio is increased by(272~560)%.Compared to the secondary air conditioning system,the average system performance ratio is increased by 28.4% for constant 10% fresh air ratio,increased by 24.2% for constant 20% fresh air ratio and increased by 23.5% for constant 30% fresh air ratio.The new system will be improved by replacing some fresh air with return air to realize the air treatment process when the actual fresh air volume is small.The numerical analysis shows that the improved system can realize all the air treatment process in the dehumidification range,compared to the primary return air conditioning system and the secondary air conditioning system,the improved system also shows a huge energy-saving potential.The new system achieves return air cooling and fresh air pre-cooling through(16~18)? high temperature cold water.The COP of high temperature chiller is higher than the traditional(5~7)? low temperature chiller's,so the system performance coefficient will be increased accordingly.For a suitable natural cold source area,the system performance coefficient is bound to further increase and the system energy efficiency potential will be greater.For the air conditioning system with independent exhaust ventilation,fresh air can be cooled down in the whole heat exchanger which and exchanging heat and moisture content with the exhaust.This method will greatly reduce the high temperature cold water consumption and then improve the system performance coefficient.