Abstract: To solve the limitation of traditional closed sprinkler installation, the heat absorption mode of traditional closed sprinkler is analyzed, the reason why the traditional closed sprinkler cannot effectively absorb radiant heat is revealed. According to the basic principle of radiant heat, a method to improve the absorption of radiant heat by the temperature sensing element of the sprinkler is proposed, and the radiant heat start- up sprinkler is designed and developed.In order to verify the start- up advantages of the radiant heat start- up sprinkler, tests of radiant heat source and oil pan fire are conducted, and the start- up performance of the radiant heat start- up sprinkler and the traditional closed sprinkler was compared. The results show that the radiant heat start- up sprinkler can be started by absorbing the radiant heat when it is unable to conduct convection heat exchange with the hot flue gas. This paper analyzes and summarizes the factors that affect the start- up speed of sprinkler and the heat exchange of radiant heat start- up sprinkler under the actual fire conditions.

Key words: sprinkler, radiant heat, temperature sensing element, starting speed