Abstract: The protective cooling water curtain can play a good role in protecting the glass curtain wall at the initial stage of fire. However, if the water curtain is delayed to start, the heated glass may be accelerated to crack and fall off under the instantaneous action of cooling water. The experiment verified that the tempered glass and low-radiation (Low-E) glass can withstand the critical temperature range of the water curtain protection: in the control group without starting the water curtain, the tempered glass of 6 mm did not break until the fuel burned out, the highest temperature of the glass over 400 ℃, but the glass temperature over 250 ℃ opening the water curtain will accelerate its rupture; 6 mm low-E glass temperature over 70 ℃ after the same is no longer suitable for direct cooling with water curtain cooling. Starting the water curtain in time within the critical temperature can play a good protective cooling effect, but beyond the critical temperature, other measures should be taken. Based on the above research conclusions, the countermeasures and suggestions on the revision of relevant standards, engineering application and improvement of spray products are put forward.

Key words: Key words: glass curtain wall, protective cooling water curtain, fire separation, critical temperature