US-12618589-B2 - Electric boiler

US12618589B2US 12618589 B2US12618589 B2US 12618589B2US-12618589-B2

Abstract

The present invention provides an electric boiler having a heating element surrounded by a thermally conductive inner container to define an inner passage about the heating element, the inner container having an inlet and an outlet for a flow of water and is arranged such as to cause water received at the inner container inlet to flow along the inner passage in close proximity to a surface of the heating element, the boiler further comprising an outer container in which the inner container is substantially located, the outer container defining an outer passage about at least part of the inner container, the outer container having an outlet into the inner container wherein the outer container is arranged such as to cause water to flow along the outer passage in close proximity to a surface of the inner container, such that water received in the boiler makes at least a double pass through the boiler to increase the potential heat transfer to the water.

Inventors

Jaskiran Singh Nagi

Assignees

Jaskiran Singh Nagi

Dates

Publication Date: 20260505
Application Date: 20210210
Priority Date: 20200212

Claims (13)

1 . An electric boiler comprising a plurality of heating element cartridges that are each substantially cylindrical in one or more inner containers that are each thermally conductive, at least one inner container surrounding one or more heating element cartridges of the plurality of heating element cartridges to define an inner passage about the one or more heating element cartridges, the at least one inner container having an inlet and an outlet for a flow of water and being arranged such as to cause water received at the inner container inlet to flow along the inner passage, in close proximity to a surface of the one or more heating element cartridges to the inner container outlet, the electric boiler further comprising an outer container in which the at least one inner container is substantially located, the outer container defining an outer passage extending around at least part of the at least one inner container, the outer container having an inlet and at least one outlet for a flow of water, wherein the at least one outer container outlet is connected to, or forms, at least one inner container inlet, wherein the outer container is arranged such as to cause water received at the outer container inlet to flow along the outer passage in close proximity to a surface of the at least one inner container to the at least one outer container outlet, and wherein the at least one inner container is shaped to have an inner surface that at least in part follows the profile of an outer surface of at least one heating element cartridge, to define at least one partly confined portion of the inner passage for water to flow between the at least one inner container and the at least one heating element cartridge, wherein the plurality of heating element cartridges are arranged in a cylindrical pattern with the outer surface of the one or more inner containers defining a continuous inner wall of the outer container.
2 . An electric boiler as claimed in claim 1 , wherein the inner and outer passages are arranged such that, in use, water in the outer passage progresses along the outer passage in a direction opposite to the direction in which water progresses along the inner passage.
3 . An electric boiler as claimed claim 1 , wherein the one or more inner containers consists of a single inner container in which the plurality of heating element cartridges is located.
4 . An electric boiler as claimed in claim 1 , wherein the plurality of heating element cartridges comprises a plurality of elongate heating element cartridges, the at least one inner container comprises a plurality of tubular inner containers, and each elongate heating element of the plurality of elongate heating elements is arranged concentrically within an associated tubular inner container of the plurality of tubular inner containers.
5 . An electric boiler as claimed in claim 4 , wherein the plurality of tubular inner containers are arranged side by side in a cylindrical pattern and connected to each other to define a central passage within the electric boiler, whereby the tubular inner containers are aligned with a longitudinal axis of the electric boiler and wherein the electric boiler is arranged such that water enters through the at least one outer container at or towards a first end of the electric boiler and travels in a first longitudinal direction along the outer passage to exit the outer passage through the at least one outer container outlet at or towards a second end of the electric boiler opposite to the first end, to enter the tubular inner containers through respective inner container inlets located at or towards a second end of the electric boiler, the water then passing along the respective inner passages to exit via respective outlets of the tubular inner containers, located at or towards the first end of the electric boiler, to enter the central passage and pass along the central passage towards the second end of the electric boiler.
6 . An electric boiler as claimed in claim 4 , wherein the at least one outer container comprises at least two end portions and a cylindrical portion extending therebetween in which the plurality of tubular inner containers are located, wherein each heating element cartridge is secured in place in one of the two end portions.
7 . An electric boiler as claimed in claim 1 , wherein the outer container inlet is arranged to direct water tangentially into the outer passage so that the water spirals around the at least one inner container as the water progresses along the outer passage to the at least one outer container outlet.
8 . An electric boiler as claimed in claim 1 , further comprising one or more ultrasonic transducers arranged to dislodge or breakdown any scale or similar accumulations of solid material from within the electric boiler.
9 . An electric boiler as claimed in claim 1 , wherein the outer container is a first outer container, the electric boiler further comprising a second outer container in which the first outer container is located, wherein the first outer container and second outer container share a common thermally conductive wall, the second outer container having an inlet and an outlet and defining a second outer container passage arranged to convey water in close proximity to the common thermally conductive wall from the inlet to the outlet of the second outer container, and wherein the passage of the second outer container is in fluid isolation from both the passage of the first outer container and the passage of the at least one inner container.
10 . A central heating and hot water system comprising an electric boiler as claimed in claim 9 , the electric boiler further comprising a first inlet connected to a sanitary water supply and a first outlet arranged to supply sanitary water heated once by the electric boiler, the electric boiler further comprising a second inlet connected to a central heating return and a second outlet, wherein the electric boiler is configured such that sanitary water to be heated enters through the first inlet of the electric boiler, before being received by and passing through the first outer container passage and at least one inner container passage before and then exiting the electric boiler through the first outlet of the electric boiler, and such that water from the central heating system to be heated enters through the second inlet of the boiler and passing through the passage of the second outer container, before then exiting the electric boiler through the second outlet of the electric boiler to be recirculated around the central heating system.
11 . A central heating system as claimed in claim 10 , further comprising a pump for circulating water around the central heating system, a temperature sensor for detecting the temperature of water returning to the electric boiler through the second inlet, a flow or pressure sensor for detecting the flow of sanitary water through the electric boiler and a controller arranged to control the pump at least in part in dependence on signals received from the temperature sensor and the flow or pressure sensor, wherein the pump is activated if it is detected that sanitary water is being drawn through the electric boiler and that the temperature of the central heating water returning to the electric boiler is above a predetermined temperature and wherein the pump is deactivated if the temperature of the water returning to the electric boiler from the central heating system is below a predetermined temperature.
12 . An electric boiler comprising: a plurality of elongate heating element cartridges that are each substantially cylindrical; a plurality of tubular inner containers surrounding the plurality of elongate heating element cartridges, with each elongate heating element cartridge of the a plurality of elongate heating element cartridges being arranged concentrically within an associated tubular inner container of the plurality of tubular inner containers to define an inner passage about the heating element cartridge, each tubular inner container being thermally conductive, having an inlet and an outlet for a flow of water, and being arranged such as to cause water received at the inner container inlet to flow along the inner passage, in close proximity to a surface of the concentrically arranged elongate heating element cartridge to the inner container outlet; and an outer container in which the plurality of tubular inner containers is substantially located, the outer container defining an outer passage extending around at least part of each tubular inner container, the outer container having an inlet and at least one outlet for a flow of water; wherein the at least one outer container outlet is connected to, or forms, at least one inner container inlet; and wherein the outer container is arranged such as to cause water received at the outer container inlet to flow along the outer passage in close proximity to surfaces of the tubular inner containers to the at least one outer container outlet.
13 . An electric boiler as claimed in claim 12 , wherein the plurality of tubular inner containers are arranged side by side in a cylindrical pattern and connected to each other to define a central passage within the electric boiler, whereby the tubular inner containers are aligned with a longitudinal axis of the electric boiler and wherein the electric boiler is arranged such that water enters through the at least one outer container at or towards a first end of the electric boiler and travels in a first longitudinal direction along the outer passage to exit the outer passage through the at least one outer container outlet at or towards a second end of the electric boiler opposite to the first end, to enter the tubular inner containers through respective inner container inlets located at or towards a second end of the electric boiler, the water then passing along the respective inner passages to exit via respective outlets of the tubular inner containers, located at or towards the first end of the electric boiler, to enter the central passage and pass along the central passage towards the second end of the electric boiler.

Description

This application is a 35 U.S.C. § 371 national phase filing of International Application No. PCT/GB2021/050308, filed on Feb. 10, 2021, and claims the benefit of United Kingdom Patent Application No. 2014928.2 filed on Sep. 22, 2020 and United Kingdom Patent Application No. 2001908.9 filed on Febraury 12, 2020, wherein the entire contents of the foregoing applications are hereby incorporated by reference herein. The present invention relates to an electric boiler and particularly, but not exclusively, to an electric boiler suitable for heating sanitary water in a domestic or commercial premises, or suitable for use in a central heating system. Generally, electric boilers have in the past tended to be predominantly used for single point of supply applications, for example electric showers, hot water supplies for single (or local) wash hand basins or similar, where it is not desired to install a traditional central emersion heater or fossil fuel boiler. This could be to avoid the expense and possible disruption associated with installing larger heating systems, or where there is a desire to ensure a reliable instantaneous supply of hot water. However, more recently electric boilers are also being used more commonly in place of the more traditional fossil fuel boiler, where they centrally provide hot water to a number of sanitary outlets and/or form the boiler of a central heating system. These new applications for electric boilers require far more powerful boilers than those traditionally used in the examples mentioned above. It is an object of the present invention to provide a particularly compact arrangement of electric boiler which is capable of providing an instantaneous hot water supply, suitable for a sanitary hot water supply or for a central heating system. According to the present invention there is provided an electric boiler comprising a heating element and a thermally conductive inner container, the inner container substantially surrounding the heating element to define an inner passage about the heating element, the inner container having an inlet and an outlet for a flow of water and being arranged such as to cause water received at the inner container inlet to flow along the inner passage in close proximity to a surface of the heating element to the inner container outlet, the boiler further comprising an outer container in which the inner container is substantially located, the outer container defining an outer passage about at least part of the inner container, the outer container having an inlet and an outlet for a flow of water, wherein the outer container outlet is fluidly connected to, or forms, the inner container inlet and wherein the outer container is arranged such as to cause water received at the outer container inlet to flow along the outer passage, in close proximity to a surface of the inner container, to the outer container outlet. By having an inner container substantially surrounding the heating element, the inner container can be arranged to concentrate the flow of water over the surface of the heating element, providing only a small clearance between a surface of the container and a surface of the heating element and thus a low volume space through which water is forced to flow at high flow rates, providing a high heating surface area to volume ratio. The advantage of such an arrangement is that there is very little inertia within the boiler, due to the relatively low volume of water stored within the boiler and thus the boiler may function as an instantaneous hot water heater, at least at the point where the water leaves the boiler. This not only has the benefit of being able to quickly provide a source of hot water, without the need to have a cylinder of preheated hot water, but it may also minimise the residual energy stored within the boiler after hot water has been drawn from the boiler. The provision of an outer container, in which the inner container is substantially located, enables water being drawn into an inlet of the boiler to be preheated, by first passing through the outer container and absorbing heat from the inner container, particularly if the inner container and outer container share a common thermally conductive wall, before being drawn through the inner container where it comes into contact with the heating elements. A boiler in accordance with the present invention can thus be used to increase the area of heated surface a relatively small volume of water comes into contact with, which may enable significantly more energy to be extracted from the heating elements without causing the water to boil at any point. Preferably, the inner and outer passages are arranged such that in use water in the first inner passage progresses along the first passage in a direction opposite to the direction in which the water progresses along the second passage. The above arrangement may provide a particularly compact arrangement of boiler that is relatively inexpensive to c