Electric fluid heater

Abstract

There is disclosed a partially or wholly electric fluid heater (100) arranged to heat fluid in a first circuit, the fluid comprising heating fluid or tap water. The heater (100) comprises: a first electric heating element (108) arranged to heat fluid in the first circuit; and a DC power supply (120) arranged to at least partially power the first heating element. The DC power supply has a capacity of at least 1 kWh, and optionally at least 5 kWh.

We claim: 
     
         1 . A partially or wholly electric fluid heater arranged to heat fluid in a first circuit, the fluid comprising heating fluid or tap water, wherein the heater comprises a heater housing arranged to house:
 a first heater vessel containing a first electric heating element arranged to heat fluid in the first circuit; and   a DC power supply arranged to at least partially power the first heating element, the DC power supply having a capacity of at least 1 kWh,   
       wherein the heater further comprising a heat shield located between the DC power supply and the first heater vessel. 
     
     
         2 . The heater of  claim 1  further arranged to heat fluid in a second circuit, wherein the fluid in the first circuit comprises heating fluid and the fluid in the second circuit comprises tap water or vice versa; and wherein the first heating element is arranged to heat fluid in the first circuit or both the first circuit and the second circuit. 
     
     
         3 . The heater of  claim 1  comprises an electric control unit arranged to control any one or more of: heating, DC power supply charging, DC power supply discharging, system requirements, switching of the DC power supply. 
     
     
         4 . The heater of  claim 1  comprises a cooling system arranged to provide cooling to the electric control unit, the DC power supply or both. 
     
     
         5 . The heater of  claim 4  wherein the cooling system comprises a coolant circuit having a coolant input pipe arranged to carry input coolant to the DC power supply or electric control unit or both, a coolant output pipe arranged to carry output coolant away from the DC power supply or electric control unit or both, and a coolant radiator arranged to receive the output coolant pipe and dissipate heat therefrom before recirculation of the coolant to the coolant input pipe, wherein the coolant output pipe, the radiator or both are configured to transfer heat to any one or more of: the fluid in the first circuit; the fluid in the second circuit; a heater cold water input pipe; a heater cold fluid intake; and a heater heating fluid return pipe. 
     
     
         6 . The heater of  claim 1  wherein the DC power supply comprises a battery pack, optionally a compact battery pack. 
     
     
         7 . The heater of  claim 1  wherein the heater housing has dimensions 390 to 440 cm width by 270 to 365 cm depth by 600 to 825 cm height. 
     
     
         8 . The heater of  claim 4 , wherein the heater housing is arranged to house the cooling system. 
     
     
         9 . The heater of  claim 7  wherein the DC power supply is located at a front side, in use, of the housing, or in the top portion, in use, of the housing. 
     
     
         10 . The heater of  claim 7  wherein the DC power supply:
 substantially fills the space between front and back ends of the housing; and 
 substantially fills the space between left and right sides of the housing. 
 
     
     
         11 . The heater of  claim 7 , wherein the housing comprises an access door arranged to allow access to internal components of the heater and the DC power supply is arranged within or integrally with the access door. 
     
     
         12 . The heater of  claim 1  further comprises a combustion heater, such as a gas or oil burner, arranged to heat fluid in the first circuit, the second circuit or both. 
     
     
         13 . The heater of  claim 12  wherein the first heating element is arranged to heat fluid in the first circuit, and the combustion heater is arranged to heat fluid in the second circuit. 
     
     
         14 . The heater of  claim 1 , further comprises a second electric heating element arranged to heat fluid in the first circuit, the second circuit or both. 
     
     
         15 . The heater of  claim 14  further comprising an AC power supply arranged to at least partially power the second heating element, and wherein the first heating element is arranged to be powered only by the DC power supply and the second heating element is arranged to be powered only by an AC power supply. 
     
     
         16 . The heater of  claim 1  further comprises a controller arranged to control distribution of power taking into account any one or more of:
 capacity of the or each heating element; and 
 capacity of the or each power supply. 
 
     
     
         17 . The heater of  claim 1  comprising a DC power supply interface arranged to receive the DC power supply, and wherein the DC power supply interface is configured to receive more than one type of DC power supply, such as any combination of an Ni-MH cell battery pack, an Ni—Cd cell battery pack and a lithium cell battery pack or a mixed cell type battery pack. 
     
     
         18 . The heater of  claim 1 , comprising an AC to DC converter charger arranged to charge the DC power supply and optionally located within the housing.