The Effects Of Different Ventilation Combinations On Environmental Factors In Solar Greenhouse

In order to enhance the environmental control capability of the solar greenhouse,a forced draft fan(power:550 w/set)was installed on the back wall of the solar greenhouse(1.5 m height)to measure the different ventilation modes(top ventilation,bottom ventilation,and top ventilation).Bottom ventilated,fully enclosed)Environmental changes in different locations within the greenhouse.The test results are as follows:In the case of natural ventilation(ventilation at the top and bottom of the greenhouse),the cooling effect of the blower is obvious,the effect of the middle position is the best,which can be reduced by about 7 C,followed by the front position,which can be reduced by about 5?,and The least obvious one is the temperature at the back position,which can be reduced by about 4 C;From the effect of adjustment of the humidity,the relative humidity in the middle position increased by about 8%,the relative humidity in the back position and the front position does not change much;as about the perspective of changes in CO2 concentration,with the extending of blasting time,the CO2 concentrations of the T1 treatment and the T2 treatment were increased by about 30 ?mol/mol and 80 ?mol/mol,respectively.In the fully closed state,the cooling effect at the back position is the most obvious,which is reduced by about 15?,followed by the front position,reduced by about 14 ?,and the intermediate position is lowered by about 7?;From the effect of adjustment of the humidity,the humidity in the back position dropped by about 10%,middle position decreased by about 7%,and the effect of the front position was not obvious;there is no obvious distinction of the indoor CO2 concentration between different treatments and remained at about 400 ?mol/mol.In the top ventilation state,the cooling effect in the front position and in the middle position are the best,which are reduced by about 4 ?,followed by the back position,which is reduced by about 3?.For the effect of adjusting the humidity,the relative humidity in the back position is improved about 10%,the relative humidity in the middle position and the front position did not change much;two blower treatments increased the indoor CO2 concentration by about 80 ?mol/mol.Under the condition of bottom ventilation,the cooling effect in the front position is the best,which is reduced by about 6? to 7?,the back position is reduced by about 4?,the middle position is reduced by about 3?,and the relative humidity both in the back position and the front position are increased by about 6%to 8%,the change of the relative humidity in the middle position is not obvious;the CO2 concentration in the T2 treatment was always 180 ?mol/mol higher than that in the Tl treatment and the control(CK)treatment and remained at around 580 ?mol/mol,both during the blast treatment and after the end of the blastThe conclusion is that the forced ventilation of the back wall with a blower in the spring and summer can effectively reduce the indoor temperature and improve the relative humidity and CO2 supply.The use of two blowers(T2 treatment)in the solar greenhouse is more effective than a blower(T1 treatment)for environmental regulation;as about the effect of temperature and humidity adjustment,the use of the top and bottom ventilation methods in conjunction with the blower can make both of the temperature and humidity in greenhouse stay in the best condition,and the temperature dropped about 5? to 6?,and he relative humidity changed;the concentration of CO2 in the greenhouse increased significantly.