Water electrolysis system and temperature control method thereof

Abstract

A water electrolysis system includes a water electrolyzer, a water supply pipe, a water supply pipe, a water discharge pipe, and a first and second temperature sensors. The water electrolyzer includes a water supply port and a water discharge port. The water supply pipe is connected to the water supply port. The water is to be supplied to the water electrolyzer via the water supply pipe. The water discharge pipe is connected to the water discharge port. The water is to be discharged from the water electrolyzer via the water discharge pipe. The first temperature sensor is provided at the water supply pipe between a cooling apparatus and the water supply port to detect a temperature of the water in the water supply pipe. The second temperature sensor is provided at the water discharge pipe to detect a temperature of the water in the water discharge pipe.

What is claimed is: 
     
         1 . A water electrolysis system comprising:
 a water electrolyzer which electrolyzes water to produce oxygen and hydrogen;   a water supply pipe which supplies the water to a water supply port of the water electrolyzer; and   a water discharge pipe which allows the water, subjected to electrolysis, to be discharged from a water discharge port of the water electrolyzer, wherein   the water supply pipe is provided with a cooling apparatus, and is provided with a first temperature sensor which is located between the cooling apparatus and the water supply port and which monitors a temperature of supply water supplied to the water supply port, and   the water discharge pipe is provided with a second temperature sensor which monitors a temperature of discharge water discharged from the water discharge port.   
     
     
         2 . The water electrolysis system according to  claim 1 , wherein
 the cooling apparatus is a radiator.   
     
     
         3 . A temperature control method of a water electrolysis system including
 a water electrolyzer which electrolyzes water to produce oxygen and hydrogen;   a water supply pipe which supplies the water to a water supply port of the water electrolyzer; and   a water discharge pipe which allows the water, subjected to electrolysis, to be discharged from a water discharge port of the water electrolyzer, wherein   the water supply pipe is provided with a cooling apparatus, and is provided with a first temperature sensor located between the cooling apparatus and the water supply port, and   the water discharge pipe is provided with a second temperature sensor, the temperature control method comprising the steps of:   causing the second temperature sensor to monitor a temperature of discharge water discharged from the water discharge port of the water electrolyzer from a time of activation of the water electrolysis system; and   after the temperature of the discharge water monitored by the second temperature sensor exceeds a predetermined temperature, causing the first temperature sensor to monitor a temperature of supply water supplied to the water supply port of the water electrolyzer, and starting control of the cooling apparatus to control the temperature of the supply water.   
     
     
         4 . The temperature control method according to  claim 3 , the method further comprising
 estimating an amount of heat generated in the water electrolyzer, and based on the estimation, setting a control temperature at which to control the temperature of the supply water monitored by the first temperature sensor such that the temperature of the discharge water monitored by the second temperature sensor does not exceed a discharge water temperature threshold.   
     
     
         5 . The temperature control method according to  claim 4 , wherein
 the cooling apparatus is a radiator.   
     
     
         6 . The temperature control method according to  claim 5 , wherein
 a fan of the radiator is controlled at a maximum rotational rate when the temperature of the discharge water monitored by the second temperature sensor exceeds the discharge water temperature threshold.   
     
     
         7 . A water electrolysis system comprising:
 a water electrolyzer to electrolyze water to produce oxygen and hydrogen, the water electrolyzer including a water supply port and a water discharge port;   a water supply pipe which is connected to the water supply port and via which the water is to be supplied to the water electrolyzer;   a cooling apparatus provided in the water supply pipe;   a water discharge pipe which is connected to the water discharge port and via which the water is to be discharged from the water electrolyzer;   a first temperature sensor provided at the water supply pipe between the cooling apparatus and the water supply port to detect a temperature of the water in the water supply pipe; and   a second temperature sensor provided at the water discharge pipe to detect a temperature of the water in the water discharge pipe.   
     
     
         8 . The water electrolysis system according to  claim 7 , wherein
 the cooling apparatus includes a radiator.   
     
     
         9 . A temperature control method of a water electrolysis system including a water electrolyzer to electrolyze water to produce oxygen and hydrogen, the temperature control method comprising:
 detecting a temperature of water in a water discharge pipe, the water discharge pipe being connected to the water electrolyzer, the water being discharged from the water electrolyzer via the water discharge pipe;   detecting a temperature of the water in a water supply pipe between a cooling apparatus and the water electrolyzer after the temperature of the water detected in the water discharge pipe exceeds a predetermined temperature, the water supply pipe being connected to the water electrolyzer, the water being supplied to the water electrolyzer via the water supply pipe; and   starting the cooling apparatus to control the temperature of the water in the water supply pipe, the cooling apparatus being provided in the water supply pipe.   
     
     
         10 . The temperature control method according to  claim 9 , further comprising:
 estimating an amount of heat generated in the water electrolyzer: and   setting a control temperature at which to control the temperature of the water in the water supply pipe based on the estimated amount of heat such that the temperature of the water in the water discharge pipe does not exceed a discharge water temperature threshold.   
     
     
         11 . The temperature control method according to  claim 10 , wherein
 the cooling apparatus includes a radiator.   
     
     
         12 . The temperature control method according to  claim 11 , wherein
 a fan of the radiator is controlled at a maximum rotational rate when the temperature of the water in the water discharge pipe exceeds the discharge water temperature threshold.