Control Method of Parallel Connection Multi-heating Tank Instant Water Heater

Abstract

This invention discloses a controlling method of instant water heater having multiple heating tanks parallel with each other. The branches of the heating tanks are all set with valve unit that controls on/off of the heating tank's water inlet terminal except for one branch; the control method are: setting two flow comparison value, L1 and L2 respectively; if current tested flow rate is higher than L2, then gradually turn on branches' valve unit; if current tested flow rate is lower than L1, then gradually turn off branches' valve unit; current heating tanks separately control heating power change based on current flow rate and temperature, and heat the water in it to preset temperature, one of these heating tanks will feedback according to mixed temperature, then feedback to slightly adjust temperature control, so water heater's outlet temperature reaches set temperature completely.

1 . A controlling method of instant water heater system, wherein the instant water heater system comprises a water inlet pipe, n pcs heating tanks parallel with each other, and n-I pcs valve units, an end of each heating tanks connects to the water inlet pipe, each valve unit located between the water inlet pipe and each heating tank, wherein the method comprises the steps of:
 turning on the n−1 pcs valve units to fill the n pcs heating tanks with water;   shutting down the n−1 pcs valve units;   controlling a water flow value of each heating tanks within a pre-set range from L1 to L2, if a water flow value detected is greater than a L2, turning on the valve units until the the water flow value ranged from L1 to L2, if a water flow value detected is less than the L2, turning off the valve units until the the water flow value is ranged from L1 to L2   heating, the water filled in the heating tanks; and   mixing a heated water from the heating tanks and outputting a mixed water to the user;   wherein n is greater than two; L2 is greater than L1; each heating tank controls a heating power separately to heat the water to a predetermined temperature value depending on a water flow and a temperature detected; after the step of mixing a heated water from the heating tanks, each of the heating tank conducts a micro feedback adjustment step based on a temperature feedback after mixing to make the temperature of the outputting water are exactly the same as the preset temperature.   
     
     
         2 . The controlling method of instant water heater system of  claim 1 , wherein the flow measurement is only applied to the heating tank without the valve unit on it; and wherein a value generated by the flow measurement is compared with the preset values L1 and L2. 
     
     
         3 . The controlling method of instant water heater having multiple heating tanks parallel with each other of  claim 1 , wherein the heating tank used for micro feedback adjustment is the heating tank without the valve unit on it. 
     
     
         4 . The controlling method of instant water heater having multiple heating tanks parallel with each other of  claim 1 , wherein the controlling method further comprises a step of low water flow alarming; wherein after the step of shutting down the n−1 pcs valve units, if the value of the current flow measure is still less than L1, outputting a low water flow alarming. 
     
     
         5 . The controlling method of instant water heater having multiple heating tanks parallel with each other of  claim 2 , wherein the controlling method further comprises a step of low water flow alarming; wherein after shutting down the n−1 pcs valve units, if the value of the current flow measure is still less than L1, the low water flow alarming is output. 
     
     
         6 . The controlling method of instant water heater having multiple beating tanks parallel with each other of  claim 3 , wherein the controlling, method further comprises a step of low water flow alarming; wherein after the step of shutting down the n−1 pcs valve units, if the value of the current flow measure is still less than the L1, outputting the low water flow alarming.