Hot water supply system

Abstract

A control part of a hot water supply system is configured as follows. When a hot water flow rate in a hot water circulation path is equal to or greater than a predetermined reference flow rate when the pump is driven and an immediate hot water supply operation is being performed, and duration of this state is equal to or longer than a predetermined first time, the control part determines that a hot water supply terminal is in an opened state and stops driving of the pump. When the pump is driven during setting of a test operation mode of the hot water supply system, the hot water flow rate in the hot water circulation path at that time is detected, and the reference flow rate can be determined based on a detected value of the hot water flow rate.

1 . A hot water supply system comprising:
 a water heater, comprising an internal hot water flow path connected to a water inlet and a hot water outlet, as well as a hot water heating section provided in the internal hot water flow path, and enabling hot water entered from the water inlet to be heated before reaching the hot water outlet;   an external hot water flow path, arranged outside the water heater, and enabling hot water supply to the water inlet and hot water supply from the hot water outlet to a hot water supply terminal;   a pump for hot water circulation, configured as a separate device from the water heater, provided in the external hot water flow path, and enabling an immediate hot water supply operation in which hot water is circulated in a predetermined hot water circulation path of the external hot water flow path and the internal hot water flow path when the hot water supply terminal is in a closed state;   a control part, capable of executing on/off control of driving of the pump; and   a flow sensor, for detecting a hot water flow rate in the hot water circulation path during the immediate hot water supply operation, wherein   the control part is configured to, in response to that the hot water flow rate in the hot water circulation path is equal to or greater than a predetermined reference flow rate when the pump is driven and the immediate hot water supply operation is being performed, and duration of this state is equal to or longer than a predetermined first time, determine that the hot water supply terminal is in an opened state and stop driving of the pump; and   in a case where the pump is driven during setting of a test operation mode of the hot water supply system, the hot water flow rate in the hot water circulation path at that time is detected, and the reference flow rate is able to be determined based on a detected value of the hot water flow rate.   
     
     
         2 . The hot water supply system according to  claim 1 , wherein
 the control part, in response to driving of the pump during setting of the test operation mode being performed for a predetermined second time or longer, executes processing for determining whether a fluctuation range of the detected value of the hot water flow rate detected during a period during which the driving of the pump during setting of the test operation mode is performed for the second time or longer is a normal value within a predetermined range; and   in a case where the detected value is determined to be a normal value, the reference flow rate is determined based on the detected value, and in a case where the detected value is determined not to be a normal value, the reference flow rate is not determined based on the detected value, and the reference flow rate is able to be determined based on the detected value as a normal value obtained by repeating the processing for determining again thereafter.   
     
     
         3 . The hot water supply system according to  claim 1 , wherein
 a main water heater and a sub water heater are provided as the water heater, the main water heater being preferentially operated for a hot water supply load, the sub water heater being complementarily operated in response to an insufficient amount of heat being supplied by the main water heater alone; and   when the immediate hot water supply operation is performed, only the main water heater performs heating of hot water circulating through the hot water circulation path, while the sub water heater maintains a state of being prohibited from heating hot water, and complementary operation of the sub water heater is not allowed unless driving of the pump of the main water heater is stopped.   
     
     
         4 . The hot water supply system according to  claim 1 , further comprising:
 in the hot water circulation path, a temperature sensor for detecting a hot water temperature on an inlet side of the hot water heating section, wherein   the control part is configured to, in response to a temperature of hot water in the hot water circulation path not rising to a predetermined first temperature or higher, determine that the hot water supply terminal is in the opened state and stop driving of the pump, despite a fact a cumulative flow rate of hot water in the hot water circulation path from start of the immediate hot water supply operation has reached a predetermined reference capacity set corresponding to a capacity of the hot water circulation path.   
     
     
         5 . The hot water supply system according to  claim 4 , wherein
 the control part is configured to be able to, when the immediate hot water supply operation is performed in the test operation mode of the hot water supply system, obtain a hot water flow rate in the hot water circulation path from a point when delivery of heated hot water from the hot water heating section to the hot water circulation path is started until the heated hot water reaches the temperature sensor and a temperature detected by the temperature sensor rises to a predetermined second temperature or higher, and determine the predetermined reference capacity based on the hot water flow rate.   
     
     
         6 . A hot water supply system comprising:
 a water heater, comprising an internal hot water flow path connected to a water inlet and a hot water outlet, as well as a hot water heating section provided in the internal hot water flow path, and enabling hot water entered from the water inlet to be heated before reaching the hot water outlet;   an external hot water flow path, arranged outside the water heater, and enabling hot water supply to the water inlet and hot water supply from the hot water outlet to a hot water supply terminal;   a pump for hot water circulation, configured as a separate device from the water heater, provided in the external hot water flow path, and enabling an immediate hot water supply operation in which hot water is circulated in a predetermined hot water circulation path of the external hot water flow path and the internal hot water flow path when the hot water supply terminal is in a closed state;   a control part, capable of executing on/off control of driving of the pump;   a flow sensor, for detecting a hot water flow rate in the hot water circulation path during the immediate hot water supply operation; and   a temperature sensor in the hot water circulation path, for detecting a hot water temperature on an inlet side of the hot water heating section, wherein   the control part is configured to, in response to a temperature of hot water in the hot water circulation path not rising to a predetermined first temperature or higher, determine that the hot water supply terminal is in an opened state and stop driving of the pump, despite a fact a cumulative flow rate of hot water in the hot water circulation path from start of the immediate hot water supply operation has reached a predetermined reference capacity set corresponding to a capacity of the hot water circulation path; and   when the immediate hot water supply operation is performed in a test operation mode of the hot water supply system, a hot water flow rate in the hot water circulation path from a point when delivery of heated hot water from the hot water heating section to the hot water circulation path is started until the heated hot water reaches the temperature sensor and a temperature detected by the temperature sensor rises to a predetermined second temperature or higher is obtained, and the predetermined reference capacity is able to be determined based on the hot water flow rate.