Modularized pure water cooling system for nuclear reactor thermal hydraulic system test

The invention discloses a modularized pure water cooling system for a nuclear reactor thermal hydraulic system test, a modularized cooling source is in closed loop connection with a cooling flow channel, the modularized cooling source is detachably connected with the cooling flow channel, and the modularized cooling source is used for providing a deionized water cooling source for the cooling flow channel and receiving deionized water flowing out of the cooling flow channel; the cooling flow channel is arranged in the conductive copper structure of the reactor core simulation body and is used for cooling the conductive copper structure through the deionized water cooling source; the modularized cooling source and the cooling flow channel are in closed-loop connection and are matched with each other to realize cooling from the interior of the conductive copper structure of the reactor core simulation body, so that the cooling and heat dissipation problems of the conductive copper structure of the high-power re