The present invention relates to a multi-functional cover plate and an associated assembly of components to adapt electric water heaters to alternative electrical energy systems or thermal energy systems to heat water in its water storage tank. Examples of such alternative energy systems are solar systems using photovoltaic (PV) panels to produce electrical energy from the sun, or wind generators which harness energy from the wind to produce electrical power or recuperated thermal energy from heat exchange fluids from heat pumps or other heat exchange devices.
Due to an increasing demand for electrical energy, as well as the increasing cost thereof, attention has been directed to the development of alternative energy systems to produce electrical power. Particular attention has been given to the development of wind turbines and photovoltaic solar panels which harness energy from the wind and sun and convert such energy to electrical voltage to supply electrical devices. It is known that electric water heaters consume a great amount of electrical power when there is a need to heat water in its tank and this is accomplished by powering two or more resistive heating elements consuming in the range of about 4,000 to 9,000 watts of power when energized. Some grid providers have developed control systems in an attempt to regulate the increasing demand from the grid by appliances such as water heaters, particularly during peak periods where electricity is in an increase demand or when restoring power after a power failure on the grid. One solution to reduce this problem is to use alternative energy sources which generate electrical power to heat water in the tanks of electrical water heaters when power is available, and when conditions inside the tank permit it to do so, whereby to raise the temperature of water within the tank to reduce the consumption of electrical energy from the grid.
Reference is made to U.S. Pat. Nos. 9,885,498 and 10,151,510 wherein there is disclosed the adaptation of a dual resistive heating element mounted in an electric water heater and wherein one of the elements of the dual element is a low power rated resistive heating element dedicated to receive power from an alternative electrical power source. In recent years, increasing attention has been directed to the use of photovoltaic PV panels and wind powered generators to supply energy to households to power electrical appliances including electric water heaters. A disadvantage of such system is their cost particularly when using photovoltaic panels and further that power is not always available if there is no sun or wind. However, with respect to PA panels, and with ongoing research and development, new solar panels are being developed to cut their cost and increase their efficiency. Because solar and wind alternative energy sources produce dc voltage, with some uses it is sometimes required to convert the dc voltage to a state where it can produce a regulated AC supply adequate to operate all sorts of household appliances including electric water heaters. Accordingly, such alternative power sources incorporate circuitry and microprocessor controllers to regulate the alternative energy supply and to operate PV panel arrays, at their maximum power point, in terms of electrical energy supply, during solar irradiation fluctuations. Nevertheless, because the water holding tank of a water heater becomes a storage tank for storing heat energy, the demand of KWh from the grid is reduced resulting in a cost saving to the end user and permitting the grid provider to better manage its supply and allocate its power to other beneficial use.
Many solar energy system suppliers have developed proprietary solar systems to supply solar electrical power for various specific uses such as to charge battery packs for off-the-grid households or for other needs of such off-the-grid users. Others have proposed its connection directly to a resistive heating element of an electric water heater to convert the water heater into a hybrid electric/solar water heater. Some alternative energy suppliers have also developed their proprietary solar water heater systems, particularly those where thermal energy is obtained by the sun. However, such has proven costly and non-conventional resulting in future maintenance and repair problems.
In view of the above, it would be desirable to facilitate the adaptation of conventional electrical water heaters, using resistive heating elements to alternative energy suppliers and provide additional benefits to the end user and the grid provider by such an adaptation.
It is therefore a feature of the present invention to provide a multi-functional retrofit cover plate and assembly for use with electric water heaters to facilitate interconnection with alternative energy systems to heat water in its water holding tank to reduce the demand of electricity from the grid.
Another feature of the present invention is to provide a multi-functional retrofit cover plate and assembly wherein the cover plate has a dedicated internal compartment to accommodate an electronic switch unit and wiring connections required to adapt an alternative energy power source to an electric water heater and further provides for the mounting of other accessories of the alternative energy providers on the outer surface of the cover plate.
A further feature of the present invention is to provide a multi-functional retrofit cover plate and assembly which includes a replacement dual resistive heating element, a temperature sensor assembly and an electronic switch unit as well as all required wiring while providing electrical protection of the component assembly.
Another feature of the present invention is to provide a multi-function retrofit cover plate and assembly and wherein a display module is secured to an outer surface of the cover plate to provide an indication of the operational state of the alternative energy source connected to a dedicated resistive heating element and/or the actual water temperature in the tank of the water heater.
Another feature of the present invention is to provide a multi-functional retrofit cover plate and assembly including an electronic switching unit which prevents the water temperature within the tank of the electric water heater from exceeding a safe threshold value to prevent scalding.
Another feature of the present invention is to provide a multi-functional retrofit cover plate and assembly which includes an electronic switching unit incorporating a programmable electronic control circuit capable of causing the water temperature in the tank of the water heater to increase to a high temperature below the set temperature of the high limit switch to convert the water heater to a high temperature water heater and thereby increase the supply of hot water to the hot water distribution conduits and through a retrofit mixing valve and thereby resulting in a decrease of the demand of electricity from the grid.
A further feature of the present invention is to adapt an electrical water heater to an alternate thermal energy supply source to heat water in the tank of the water heater during predetermined water temperature conditions in the tank and when such thermal energy is available.
A still further feature of the present invention is to adapt a thermal fluid energy supply to a dual heating element having a resistive heating element and a fluid conductive conduit through which a hot fluid from an alternative energy supply is conducted.
Another feature of the present invention is to provide an electric water heater provided with a bottom dual resistive heating element and wherein a dedicated resistive heating element thereof is adapted for connection to an alternative supply voltage of a renewable energy source to heat water in a water holding tank of the electric water heater when a threshold temperature in the bottom region of the water holding tank rises above a threshold temperature as detected by a dedicated water temperature sensor mounted on the outer surface of the tank in a bottom access area of the tank.
A further feature of the present invention is to provide a method of retrofitting an electrical water heater to adapt to an alternative energy system to heat water in a water holding tank to reduce the demand on electricity from the grid and which further prevents the water temperature within the tank to exceed the set threshold water temperature of the high temperature limit switch of the water heater.
Another feature of the present invention is to provide a method of converting an electrical water heater to an alternative thermal energy system by interconnecting a dual heating element of the electric water heater to a thermal fluid supply.
According to the above features, from a broad aspect, the present invention provides a multi-functional retrofit cover plate and assembly for an electric water heater to provide interconnection with an alternative energy system to heat water in a water holding tank of the electric water heater. The retrofit cover plate assembly is comprised of a cover plate adapted for replacement connection over a bottom access opening formed in an outer casing of the electric water heater to permit access to a bottom resistive heating element and an associated thermostat and electrical connections. The retrofit cover plate has an outwardly projecting formation to define an internal dedicated compartment behind the retrofit cover plate. The retrofit cover plate is dimensioned for close retention fit against an outer surface of the outer casing to isolate the bottom access opening. The retrofit cover plate further has one or more access openings leading to the internal dedicated compartment from outside the retrofit cover plate to permit passage of wiring. The retrofit cover plate assembly further includes a dual resistive heating element for replacement of the bottom resistive heating element of the water heater. An electronic switch unit is also provided with a power cut-off switch for connection to the alternative supply voltage and a dedicated resistive heating element of the dual resistive heating element of the alternative energy system. A temperature sensor is provided for mounting against the tank outer surface to sense water temperature inside the tank and supply a sensed temperature signal to the electronic switch unit.
According to another broad aspect of the present invention, there is provided multi-functional retrofit cover plate for an electric water heater to provide interconnection with an alternative energy system generating electric power to heat water in a water holding tank of the electric water heater. The retrofit cover plate is adapted for replacement of a cover plate of a bottom access opening formed in an outer casing of the electric water heater permitting access to a bottom resistive heating element and an associated thermostat and connections of the electric water heater. The retrofit cover plate has an outwardly projecting formation to define an internal dedicated compartment behind the retrofit cover plate. The outwardly projecting formation defines one or more outer surface mounting sections for securing electrical accessories of an associated alternative energy system. The retrofit cover plate is dimensioned for close retention fit against an outer surface of the outer casing to isolate the bottom access opening. The retrofit cover plate further has one or more access ports leading to the internal dedicated compartment from outside the retrofit cover plate to permit passage of wiring. The outwardly projecting formation also permits for the mounting of accessories associated with an alternative energy system and/or other devices mounted in the internal dedicated compartment.
According to another broad aspect of the present invention there is provided a multi-functional retrofit cover plate and assembly for an electric water heater to provide interconnection with an alternative thermal fluid energy supply to heat water in a water holding tank of the electric water heater. The retrofit cover plate assembly is comprised of a cover plate adapted for replacement connection over a bottom access opening formed in an outer casing of the electric water heater permitting access to a bottom resistive heating element and an associated thermostat and electrical connections. The retrofit cover plate has one or more outwardly projecting formations to define one or more internal dedicated compartments behind the retrofit cover plate. The retrofit cover plate is dimensioned for close retention fit against an outer surface of the outer casing to isolate the bottom access opening. The retrofit cover plate further has one or more access means leading to the one or more internal dedicated compartments from outside the retrofit cover plate to permit passage of associated elements of the assembly. The retrofit cover plate assembly further includes a dual bottom element for replacement of the bottom resistive heating element. The dual bottom element has a replacement resistive heating element and a thermal fluid conductive conduit having an inlet and an outlet end to permit the flow of a hot fluid there through to heat water in said tank. The assembly further comprises an electronic control unit, a temperature sensor and a pump. The pump is adapted for connection between the alternative thermal fluid energy supply and one of the thermal fluid conductive conduit of the dual bottom element. The temperature sensor is adapted for mounting on an outer surface of the tank and for communication with the electronic switch unit for feeding a temperature signal representative of a set threshold temperature of water within the tank in a lower region of the tank. The electronic control unit controls the operation of the pump to control the flow of the hot fluid through the thermal fluid conductive conduit of the dual element for heat exchange with water in the tank.
According to another broad aspect of the present invention there is provided an electric water heater having a bottom dual resistive heating element and wherein a dedicated resistive heating element thereof is adapted for connection to an alternative supply voltage of a renewable energy source. The electric water heater has a cover plate adapted for connection over a bottom access opening formed in an outer casing of the electric water heater to permit access to the bottom dual resistive heating element and an associated thermostat and electrical connections. The cover plate has an outwardly projecting formation to define an internal dedicated compartment behind the cover plate. The cover plate is dimensioned for close retention fit against an outer surface of the outer casing to isolate the bottom access opening. The cover plate further has one or more access means leading to the internal dedicated compartment from outside the cover plate. The dedicated resistive heating element has power leads for connection to the supply voltage from the alternative energy system. An electronic switch unit is housed in the dedicated compartment and controls a power cut-off switch for connection to the alternative supply voltage and the dedicated resistive heating element of the dual resistive heating element. A temperature sensor is mounted on an outer surface of the water holding tank for feeding a temperature signal to the electronic switch unit indicative of a set threshold water temperature within the tank in a lower region thereof to cause the electronic switch unit to trip the cut-off switch upon receiving a temperature signal indicative of the threshold water temperature
According to a further broad aspect of the present invention there is provided a method of retrofitting an electrical water heater to an alternative energy system to heat water in a water holding tank of the electric water heater. The method comprises the following steps:
i) providing a retrofit cover plate for replacing an existing cover plate secured over a bottom access opening formed in an outer casing of the electric water heater to permit access to a bottom resistive heating element and an associated thermostat and electrical connections, the retrofit cover plate has an outwardly projecting formation to define an internal dedicated compartment between the retrofit cover plate and an outer surface of the outer casing;
ii) replacing the bottom resistive heating element with a dual resistive heating element having one resistive heating element which is a dedicated resistive heating element to receive alternative operating voltage from the alternative energy system;
iii) mounting a temperature sensor against an outer surface of the water holding tank to sense water temperature in a lower region of the water holding tank;
iv) mounting an electronic switch unit having a normally closed power cut-off switch in the internal dedicated compartment and establishing power connections thereto, and
v) connecting leads of the temperature sensor to the electronic switch unit to feed actual sensed water temperature signals to the electronic switch unit for the monitoring of the temperature signals to cause the normally closed power cut-off switch to open and disconnect the alternative supply voltage from the dedicated resistive heating element upon the temperature signals attaining a threshold temperature value.
According to still broad aspect of the present invention there is provided a method of connecting an electrical water heater to an alternative thermal energy system by interconnecting a dual heating element of said electric water heater to a thermal fluid supply. The method comprises the following steps:
i) providing a retrofit cover plate and an assembly for replacing an existing cover plate secured over a bottom access opening formed in an outer casing of the electric water heater permitting access to a bottom resistive heating element and electrical connections; the retrofit cover plate having one or more outwardly projecting formations to define one or more internal dedicated compartments between the retrofit cover plate and an outer surface of the outer casing;
ii) replacing the bottom resistive heating element with the dual resistive heating element having a replacement resistive heating element and the other being a thermal fluid conductive conduit adapted to receive and conduct a hot fluid there through from the alternative thermal fluid energy supply;
iii) connecting fluid circulating conduits of the alternative thermal fluid energy supply to the thermal fluid conductive conduit;
iv) mounting a fluid cut-off valve to one of the fluid conducting conduits prior to connection to the thermal fluid conductive conduit:
v) mounting a temperature sensor against an outer surface of the water holding tank to sense water temperature in a bottom region of the water holding tank;
vi) mounting an electronic switch unit having a normally closed power cut-off switch in one of the internal dedicated compartments and establishing power connections thereto;
vii) connecting leads from the cut-off switch to the pump to provide operating voltage to the pump through the cut-off switch, and
viii) establishing communication between the temperature sensor and the electronic switch unit for the temperature sensor to transmit one or more temperature signals to the electronic switch unit upon the temperature sensor detecting a predetermined threshold temperature wherein the electronic switch unit will cause the pump to stop the flow of the hot fluid through the thermal fluid conductive conduit of the dual element and resume the flow upon the water temperature in the tank falling below the threshold temperature.
A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:
Referring now to the drawings, and more particularly to
With additional reference now to
As illustrated in
With reference now to
As mentioned above,
The dedicated resistive heating element is selected to function to accommodate both dc and AC voltages and such is accomplished by the material selection for the construction of the resistive heating element to adapt it to the specification of the alternate energy supply. The dedicated resistive heating element 45, as schematically shown in
As shown in
As shown in
The sensor 32 may be of a type which is capable of monitoring the water temperature in the lower region of the tank where the temperature sensor is secured and to feed continuous temperature signals to the electronic switching circuit which is provided with a processor 54 to monitor actual temperature and to feed these signals to the module 62 secure to the outer surface of the cover plate 15. The switching circuit 50 is programmed to cause the switching circuit unit 30 to actuate the power switch 48 to an open contact position cutting off the renewable energy supplied to the dedicated resistive heating element 45 when the detected water temperature exceeds an unsafe threshold water temperature value as programmed in the processor 54.
As shown in
It is pointed out that the retrofit cover plate assembly of the present invention also provides the benefit of further modifications of the water heater should there be a desire to convert the water heater to a high temperature water heater particularly in regions where alternate energy supply is plentiful, such as in regions where there is ample sunshine hours, to maintain the water temperature above 140 degrees Fahrenheit. By mounting a mixing valve 60 on the outlet conduit 13 of the water heater, as shown in
As shown in
With reference to
The temperature sensor support clamp 66 also defines opposed forwardly projecting arms 116, also of substantially rectangular cross-section, with each arm 116 defining a flat front wall 117 lying in a common plane and each having a connecting aperture 118 to receive a forward bight portion 67′ of connecting tabs 67 formed between a pair of connecting arms 68 of a thermistor support bracket 69 for holding the thermistor 69′ associated with the bottom dual resistive heating element 18, as more clearly illustrated in
With reference now to
Many renewable energy system are known and their systems require control devices mounted in a housings or modules and some of these are provided with a display screen to display information concerning the operation of the system for monitoring. The multi-functional cover plate of the present invention, as illustrated in
In summary, the retrofit cover plate assembly of the present invention, as shown in
The standard bottom resistive heating element is replaced with the dual resistive heating element, forming part of the retrofit assembly, and which has a dedicated resistive heating element to which is connected the alternative voltage supply from the alternative energy system. The assembly further includes a temperature sensor with an adapter for mounting the temperature sensor against an outer surface of the water holding tank to sense water temperature in a lower region of the water holding tank. An electronic switch unit is further provided in the assembly with a normally closed power cut-off switch and these are mounted in the internal dedicated compartment. Electrical connections from the wiring of the thermostat and resistive heating elements are made to provide power to operate the electronic switching unit. Output leads from the temperature sensor are secured to the electronic switch unit to feed a set threshold high temperature signal when attained or to provide actual temperature signals to the electronic switch unit for the monitoring of changing temperature signals detected by the sensor to cause the normally closed power cut-off switch to open and disconnect the alternative supply voltage from the dedicated resistive heating element upon the temperature signals attaining a threshold temperature value set in the electronic switch unit.
Referring now to
The thermal fluid conductive conduit 122 is constructed from a single elongated copper tube, which is an excellent thermal conductive material, and it is shaped for entry into the port 101 through which the elements 121 and 122 protrude for contact with the water in the tank. The element 122 defines a first tube section 122′ and a second tube section 122″ which are interconnected together at their far end in a spaced-apart manner by a spiral tube section 126 to provide for additional tube length for maximum heat exchange with water within the tank. The tube connecting fittings 125, accessible at the terminal block 123, are adapted for interconnection with a pair of conduits 127 which are provided with couplings 128 with the fittings 125. The far ends of the pair of conduits connect to a remote supply of hot liquid from an alternative thermal fluid supply. This supply can be from heat exchangers such a heat pump connected to a earth energy system where heat from the ground is continuously available and absorbed by a refrigerant gas or any device in which a liquid is circulated to extract heat.
As shown in
As shown in
This further example of the preferred embodiment can be summarize as providing a method of adapting an electrical water heater to an alternative thermal energy source to extract heat from a heated fluid obtained from heat exchange source. With the modified retrofit cover plate and assembly, the existing cover plate secured over the bottom access opening is replaced by the cover plate 15′ which can accommodate different components in its assembly. The bottom resistive heating element is replaced with a dual heating element having a replacement resistive heating element and a thermal fluid conductive conduit adapted to receive and conduct a hot fluid there through from the alternative thermal fluid energy supply. Fluid circulating conduits of the alternative thermal fluid energy supply are connected to the thermal fluid conductive conduit of the dual element by fittings of a type known in the art. A pump is secured to one of the conduits from the supply source and located in a dedicated compartment of the cover plate adjacent the bottom access opening of the water heater. The electronic switch unit 30 and its cut-off switch 48 as well as the temperature sensor 32 are mounted as above described with reference to the retrofit assembly of the above described embodiment with respect to the connection to an alternative electrical voltage source. In this embodiment, when the electronic switching circuit receives a signal from the temperature sensor that a threshold temperature of the water in the tank is attained, the cut-off switch is trip causing the pump t stop pumping hot fluid through the fluid conduit of the dual element
It is within the ambit of the present invention to cover any obvious modifications of the embodiments described herein above, provided such modifications fall within the scope of the appended claims. As an example of modifications described above, the retrofit assembly also permits an easy conversion of an electrical water heater to operate as a high temperature water heater to increase the capacity of hot water supply by the use of a mixing valve and the result of which reduces the water heater power demand from the grid and a cost saving to the consumer. Also, the electronic switch unit and its sensor will prevent the high limit switch associated with the electric water heater from tripping by controlling the maximum high temperature of the water within the tank, when being heated by an alternative energy supply, and thus avoiding the need for a technician to reset the switch and also avoiding the risk of being deprived of hot water for a prolonged period of time. It is also foreseen that the retrofit cover plate could be made available in different sizes. The retrofit assembly can also be adapted to three or multiple element electric water heaters. Furthermore, the retrofit cover plate and the component assembly can be installed by the water heater manufacturer and made available to alternative energy providers, HVAC businesses. and end users.