Water heating system and a method of operating same

Abstract

A hot water system ( 10 ) comprising a water storage tank ( 14 ) and an instantaneous-type water heater ( 12 ). The water storage tank ( 14 ) has an inlet ( 22 ) and outlet ( 24 ). The instantaneous-type water heater ( 12 ) has an inlet ( 18 ), in fluid communication with a mains water supply ( 26 ), and an outlet ( 20 ), in fluid communication with the inlet ( 22 ) of the tank ( 14 ). The water heater ( 12 ) energises in response to a flow of water through the water heater ( 12 ).

1 - 21 . (canceled) 
     
     
         22 . A hot water system comprising:
 a water storage tank having an inlet and outlet; and   an instantaneous-type water heater having an inlet, in fluid communication with a mains water supply, and an outlet, in fluid communication with the inlet of the tank, the water heater being adapted to energise in response to a flow of water through the water heater; and   a diverter valve having:   an inlet in fluid communication with the mains water supply; a first outlet in fluid communication with the inlet of the water heater; and a second outlet in fluid communication with the inlet of the tank; and   a controller adapted to: receive signals indicative of the temperature of the water in the tank; and issue control signals to the valve,   wherein, when the valve is actuated, the controller is adapted to control the diverter valve to direct water to the first outlet in response in response to the temperature signal indicating that the temperature of the water in the tank is substantially equal to or below a predetermined value, and to direct water to the second outlet in response to the temperature signal indicating that the temperature of the water in the tank is substantially equal to or above the predetermined value.   
     
     
         23 . The hot water system as claimed in  claim 22 , wherein the first predetermined temperature value is about 55 Degrees C. 
     
     
         24 . The hot water system as claimed in  claim 22 , wherein the second predetermined temperature value is preferably about 75 Degrees C. 
     
     
         25 . The hot water system as claimed in  claim 22 , wherein the hot water system includes a first temperature sensor at or near the top of the tank and a second temperature at or neat the bottom of the tank and, when the valve is actuated, the controller is adapted to control the diverter valve to direct water to the first outlet in response in response to the second temperature sensor indicating a temperature substantially equal to or below a predetermined value, and to direct water to the second outlet in response to the first temperature sensor indicating a temperature substantially equal to or above the predetermined value. 
     
     
         26 . The hot water system as claimed in  claim 25 , wherein the controller is also adapted to issue control signals to the water heater which vary the amount of energy applied to the water therein and thus the temperature of the water leaving the water heater. 
     
     
         27 . A method of operating a hot water system, the method comprising:
 supplying mains water to an inlet of an instantaneous-type water heater or an inlet of a water storage tank;   directing the water from an outlet of the tank to a user controlled outlet;   monitoring the temperature of the water in the tank; and   directing the mains water to the inlet of the instantaneous-type water heater in response in response to the temperature of the water in the tank being substantially equal to or below a predetermined value, and directing the mains water to the inlet of the water storage tank in response to the temperature of the water in the tank being substantially equal to or above the predetermined value.   
     
     
         28 . A hot water system comprising:
 a water storage tank having an inlet and outlet;   an instantaneous-type water heater having an inlet, in fluid communication with a mains water supply, and an outlet, in fluid communication with the inlet of the tank, the water heater being adapted to energise in response to a flow of water through the water heater; and   a first pump having an inlet, in fluid communication with an additional outlet of the tank, and an outlet, in fluid communication with the inlet of the water heater; and   a controller adapted, upon user instruction, to energise the pump and cause water to direct water from the outlet of the water heater to the inlet of the tank and from the second outlet of the tank to the inlet of the water heater, in order to heat the water in the tank.   
     
     
         29 . The hot water system as claimed in  claim 28 , wherein the controller is adapted to vary the speed of the pump, so as to vary the dwell time of the water passing through the heater and thus the temperature of the water at the outlet of the heater. 
     
     
         30 . The hot water system as claimed in  claim 28 , wherein the additional outlet of the tank is at or near the top of the tank and the second inlet of the tank is at or near the bottom of the tank. 
     
     
         31 . The hot water system as claimed in  claim 28 , wherein the additional outlet of the tank is at near the top of the tank and the tank inlet is at or near the middle of the tank. 
     
     
         32 . A method of operating a hot water system, the method comprising:
 energising a pump to direct water from into the inlet of an instantaneous-type water heater;   energising the instantaneous-type water heater in response to water flow therethrough;   directing the heated water from the outlet of the instantaneous-type water heater to the inlet of a water storage tank; and   directing the water from an outlet of the tank to the inlet of the instantaneous-type water heater,   whereby the water in the tank can, upon user instruction, be circulated through the instantaneous-type water heater to heat the water in the tank.   
     
     
         33 . The method as claimed in  claim 32 , wherein the method also comprises varying the speed of the pump, so as to vary the dwell time of the water passing through the heater and thus the temperature of the heated water at the outlet of the heater. 
     
     
         34 . A hot water system comprising:
 a water storage tank having first and second inlets and first, second and third outlets;   an instantaneous-type water heater having an inlet, in fluid communication with the first outlet of the tank, and an outlet, the water heater being adapted to energise in response to a flow of water through the water heater;   a first pump having an inlet, in fluid communication with the outlet of the water heater, and an outlet, in fluid communication with the first inlet of the tank;   a second pump having an inlet, in fluid communication with the mains water supply and the second outlet of the tank, and an outlet;   at least one solar panel having an inlet, in fluid communication with the outlet of the second pump, and an inlet, in fluid communication the second inlet of the tank; and   a controller selectively adapted to energise the first and/or the second pump and cause water to circulate between the water heater and the tank and/or between the at least one solar panel and the tank respectively.   
     
     
         35 . The hot water system as claimed in  claim 34 , wherein the first outlet of the tank is at or near the top of the tank. 
     
     
         36 . The hot water system as claimed in  claim 34 , wherein the second outlet of the tank is at or near the bottom of the tank. 
     
     
         37 . The hot water system as claimed in  claim 34 , wherein the third outlet of the tank is at or near the top of the tank. 
     
     
         38 . The hot water system as claimed in  claim 34 , wherein the first inlet of the tank is at or near the middle of the tank. 
     
     
         39 . The hot water system as claimed in  claim 34 , wherein the second inlet of the tank is at or near the middle of the tank. 
     
     
         40 . A method of operating a hot water system, the method comprising:
 energising a first pump to direct water from into the inlet of an instantaneous-type water heater;   energising the instantaneous-type water heater in response to water flow therethrough;   directing the heated water from the outlet of the instantaneous-type water heater to the inlet of a water storage tank;   directing the water from an outlet of the tank to the inlet of the instantaneous-type water heater;   energising a second pump to direct water into the inlet of at least one solar panel;   directing the heated water from an outlet of the at least one solar panel to an inlet of a water storage tank;   directing the water from an outlet of the tank to the inlet of the at least one solar panel,   whereby the water in the tank can be circulated through the instantaneous-type water heater and/or the at least one solar panel to heat the water in the tank when required.   
     
     
         41 . A hot water system comprising:
 a water storage tank having first and second inlets and first and second outlets;   an instantaneous-type water heater having an inlet and an outlet, in fluid communication with the first inlet of the tank, the water heater being adapted to energise in response to a flow of water through the water heater;   a pump having an inlet, in fluid communication with the first outlet of the tank and with a mains water supply, and an outlet;   a diverter valve having: an inlet in fluid communication with the outlet of the pump; a first outlet in fluid communication with the inlet of the water heater; and a second outlet;   at least one solar panel having an inlet, in fluid communication with the second outlet of the diverter valve, and an outlet, in fluid communication the second inlet of the tank; and   a controller adapted to selectively energise the second pump and to control the diverter valve to direct water to the first outlet to circulate water between the water heater and the tank or to direct water to the second outlet to circulate water between the at least one solar panel and the tank.   
     
     
         42 . The hot water system as claimed in  claim 41 , wherein the diverter valve includes a third outlet in fluid communication with atmosphere. 
     
     
         43 . The hot water system as claimed in  claim 41 , wherein the first outlet of the tank is at or near the top of the tank. 
     
     
         44 . The hot water system as claimed in  claim 41 , wherein the second outlet of the tank is at or near the bottom of the tank. 
     
     
         45 . The hot water system as claimed in  claim 41 , wherein the first inlet of the tank is at or near the top of the tank. 
     
     
         46 . The hot water system as claimed in  claim 41 , wherein the second inlet of the tank is at or near the middle of the tank. 
     
     
         47 . A method of operating a hot water system, the method comprising:
 energising a pump;   directing water from an outlet of the pump into:
 (1) an inlet of an instantaneous-type water heater; 
 energising the instantaneous-type water heater in response to a flow of water through the heater; 
 directing the heated water from the outlet of the instantaneous-type water heater to the inlet of a water storage tank; and/or 
 (2) directing the water from the outlet of the pump to an inlet at least one solar panel; 
 directing the heated water from an outlet of the at least one solar panel to an inlet of a water storage tank; and 
 directing the water from an outlet of the tank to the inlet of the at least one solar panel, 
   whereby the water in the tank can be circulated through the instantaneous-type water heater and/or the at least one solar panel to heat the water in the tank when required.   
     
     
         48 . The hot water system as claimed in claim  5 , wherein the system includes at least one water tank temperature sensor in signal communication with the controller. 
     
     
         49 . The hot water system as claimed in  claim 48 , wherein the system includes a first water tank temperature sensor near the top of the tank and a second water tank temperature sensor near the bottom of the tank. 
     
     
         50 . The hot water system as claimed in  claim 49 , wherein the system also includes a third water tank temperature sensor near the middle of the tank. 
     
     
         51 . The hot water system as claimed in  claim 49 , wherein the controller is adapted to determine a temperature gradient across the height of the tank using at least two of the first, second and third temperature sensors. 
     
     
         52 . The hot water system as claimed in  claim 49 , wherein the controller is adapted to determine a temperature gradient across the height of the tank using all of the first, second and third temperature sensors.