WO2022150003A1

WO2022150003A1 - Water recirculation system for heating and cleaning of domestic water

Info

Publication number: WO2022150003A1
Application number: PCT/SE2022/050001
Authority: WO
Inventors: Henrik Eriksson
Original assignee: Evolution Homes Sweden Ab
Priority date: 2021-01-07
Filing date: 2022-01-02
Publication date: 2022-07-14
Also published as: SE545363C2; SE2130007A1

Abstract

A water recirculation system (1) for heating and cleaning of domestic water, comprising a first (11) and a second pipe circuit (12). The water recirculation system (1) is configured to switch between a heating mode and an operational mode. In the heating mode the water is recirculated in the first pipe circuit (11) for the water to be heated until the water reaches a predetermined temperature. In the operational mode the water is recirculated in the second pipe circuit (12) for the water to be made available for a user, and further being circulated back for being reheated.

Description

WATER RECIRCULATION SYSTEM FOR HEATING AND CLEANING OF

DOMESTIC WATER

Technical field

[0001] The present invention relates to a water recirculation system for heating and cleaning of domestic water.

Background

[0002] To reduce water and energy consumption when showering, circulation of used water is a known possibility (DE 3436941, SE8106668-0, SE 9103463-7,

EP 13174038.3, EP2793667, US20170145669A1 , EP2297407).

[0003] DE 3436941 describes a shower intended for use after a sauna bath where also rinsing water is circulated.

[0004] SE8106668-0 describes a shower with filter and closed water circulation. Water is stored in two containers and returned to one container. A thermostatically controlled heating coil is used in a water tank for heating water in the circulation circuit. The heating coil is powered by 12 volts DC, either from a battery or a transformer. The shower requires no connection to running cold or hot water and can be used anywhere. In order to end the shower, the shower nozzle is kept outside a shower tray.

[0005] SE9103463-7 describes a circulation circuit in a shower cubicle. Water purification is conducted using a disposable filter in cardboard or plastic, as well as a filter with activated carbon and a UV filter. In the cabin a control arm is electrically connected to a control mechanism, for example a two-way valve, which directs the connection with a drainage and a collection container. The cabin is equipped with a supply line for hot and cold water respectively. Heat exchange in the circuit takes place using a thermostat controlled heating coil in a collecting container, which in another embodiment is replaced by adding hot water to a loop.

[0006] EP13174038.3 describes a method in which hot water is continuously supplied a recycling circuit to maintain a comfortable shower water temperature. The method is characterised by initial filling of a basin from a hot fresh water supply through a pump, until the desired shower water volume is reached.

[0007] EP2793667 describes a combination of a shower with water recovery and a conventional shower that can take over if the circulation does not work. The hybrid shower has a flow meter for indication of filter change, and uses flow heating of water in a circulation circuit, where the power 6.5 kW and the volume 10 litres are mentioned. The shower is characterised of purification and recirculation, until water with contaminants at a predetermined maximum level, as indicated by a water quality sensor, is removed from the recycling process to a sewer.

[0008] US20170145669A1 describes a recycling circuit with a microprocessor, as well as the use of wireless communication such as bluetooth.

[0009] EP2297407 discloses an optical detection device for controlling the removal of contaminants in a shower system which circulates water. The document also states that a large amount of the water supplied to a shower process is clean.

[0010] As described in SE9103463-7, known methods and combinations thereof can be used for the purification of used water, such as filters and purification with chlorine, bromine, UV-C light and ozone to capture, oxidize, precipitate or destroy contaminated material. EP02797969.9 proposes, for example, the decomposition of endocrine substances by a combination of ozone (0.1 - 0.15 g / m3 water) and UV light (wavelength 200-300 nm). Filter technology has also been developed, US-A-5234583 and US-B2-7390343, which without requiring as high a pressure as semiperable filters, provide a high degree of chemical-free water purification. With electropositive membrane filtration, where the sterile filter is raised and coated with activated carbon, particles down to 0.02 microns can be captured. This reduces organic material such as bacteria, parasites and viruses, as well as smell and taste.

[0011] It is further known that hot water for shower circulation, as in EP13174038.3, can come from boilers or from flow heaters, which are usually designed to achieve temperatures above 50 ° C (122 ° F) for reduced risk of bacterial growth, such as legionella. Flow heaters with resistors that are heated with electricity are known, as are those that use gas for heat exchange.

[0012] SE510470.C2 describes, for example, a heater adapted to caravans and other mobile homes with small spaces. By means of a burner, which consists of a burner pipe in a pipe-in-pipe system with flanges, LPG or the like is combusted, whereby airborne central heating and hot tap water are obtained. The temperature of the heating medium varies between 70 - 80 ° C (158 - 176 ° F).

[0013] Special variants of conventional showers with gas-fired flow heating go under names such as camping shower, mini shower and the like. They are connected to a garden hose for water supply and at about 0.125 liters per second, such showers can, under optimal conditions, heat water to about 9 - 25 ° C (48 - 77 ° F). The heating is regulated by varying the water flow and the amount of gas supplied.

[0014] Known shower devices and methods where used shower water circulates give in comparison with conventional showers, a large reduction in water and energy. However, there are various disadvantages and additional savings that can be made to achieve significant system benefits, regardless of whether showering takes place in households, in nature, in disaster areas, or other environments.

[0015] DE 3436941, for example, lacks water purification in the circulation of water, which can be a disadvantage from a hygiene perspective. SE8106668-0 has purification with filters in the circulation, but lacks means to recover discharged wastewater after showering, which may be a disadvantage in situations of water scarcity. SE9103463-7 describes a circulation circuit in a shower enclosure, which is a design that can be a disadvantage in mobile or stand-alone contexts. EP2793667 suggests as a hybrid shower use in shower space and permanent connections to get hot shower water, which can be a disadvantage during installation. [0016] Furthermore, sensors and other electronics have been proposed (US20170145669A1, EP229740, EP2793667) in showers circulating water. In some situations exclusion of such components may be desirable, for example for robustness in humid environments or to save water and energy.

[0017] As an example, sensors for water quality can be mentioned, which regulate when water during showering is taken to circulation and purification, or removed via a drainage system (EP2297407, EP2793667). A disadvantage when a relatively large quantity of water is removed, is that the water consumption becomes greater, than if only pollutants are continuously separated, destroyed, or precipitated and the remaining water is recovered. If a removed amount of water also is replaced to achieve water balance in an ongoing circulation, more water is consumed. In situations with good water supply, this is not a major problem, but in a context with water shortage, such consumption can be a disadvantage. A small amount of water in a circulation circuit also requires less energy for heating to achieve shower comfort.

[0018] As a further example, flow sensors for early indication of filter change in a circulating circuit with sterile filter is mentioned (EP2793667). Sterile filters do not let through polluted water, but clogs and eventually results in the disruption of water supply, which may indicate the need for filter replacement. In situations where early indication is not important, sensors may for this purpose be redundant and involve cost disadvantages.

[0019] Hitherto known showers of similar type show solutions where usually hot water flows via a shower nozzle. The water then falls to floor level and is then cooled by approximately 2 - 5 ° C (35 - 41 ° F). These and other heat losses in the circulation need to be continuously compensated to maintain shower comfort, which usually means a shower water temperature between 35 - 43 ° C (95 - 109 ° F) during the approximately 6 minutes that a user on average showers. Even initially supplied water may need to be heated for comfort reasons, for example as it can take a while before hot water from a boiler reaches a tap point. It is important to realise that the former losses are relatively small and constant with each recovery cycle, while heating cold water at the beginning of the shower process requires relatively much added energy. To meet these heating needs altogether, various alternatives and combinations for heat exchange have been proposed in showers that circulate water. These alternatives mainly relate to heating with the help of hot water or with electricity.

[0020] EP13174038.3 describes, for example, a method in which hot water is continuously supplied to a circulation circuit. In addition to the fact that the method suggests constant water connection to an external source, which can limit independent use in, for example, nature, a disadvantage is that a quantity of water may usually be discharged into the circulation, for example via a drain, to maintain water balance. In situations of water shortage, such water consumption can be disadvantageous and provide a higher energy consumption.

[0021] SE9103463-7 describes heating of used shower water by means of a hot water circuit. When such a circuit is separated from the shower circuit, an additional water pump may be required to drive the heat flow, which is disadvantageous in connection with limited electricity supply.

[0022] Other heating possibilities in the circulation circuit are using electric heat exchange, such as for example with a heating coil as described in SE8106668-0, or with flow heaters. Here, too, electricity consumption can be a disadvantage in shortage situations.

[0023] Heating coils, such as an immersion heater in a water reservoir, may be suitable for small volumes of water and lower flows, but may result in disadvantages with regards to comfort at higher flows, which many users prefer. Flow heaters, as in EP279366, require flow and are usually placed at a tapping point. They often reach a high temperature quickly, but have the disadvantage that the heating requires a lot of energy just when hot water is needed. Other disadvantages and problems with flow heating in showers that circulate water are that the power is adapted to cope with heating in an initial phase and that such heaters are comprised in a circuit with the shower water. Electric flow heaters in showers with circulating flow have a specific disadvantage in that, due to the electricity consumption, they require a permanent electrical connection to a larger electrical system, such as in a household connected to a general electrical system. Such a connection can have a limiting effect on stand-alone use and make installation more difficult in installations intended for showering in newly built or renovated houses. These types of construction work are costly and do not happen very often. Due to risks such as leakage, professionals should be engaged. As the risk of personal injury is significantly less if you are dry than if you are wet and undressed in a wet environment, then electrical installations in humid spaces must be carried out by a qualified electrician, and have a voltage limited to 12 V AC or 30 V DC. All taken together, these circumstances can inhibit the spread of showers with this kind of heating in the circulation of water.

[0024] Showers with water circulation, which use electricity for operation of various components, can, as in SE8106668-0, for example be supplied with electricity from a transformer or from an energy storage, which can be located outside or inside such a device. A transformer indicates a permanent electrical connection with the mentioned disadvantages during installation. An internal energy storage can instead facilitate installation in shower areas, as well as freestanding and mobile use, but has disadvantages such as limited capacity and required charging at short intervals, especially if electricity consumption is high and space is scarce. This focuses on saving electricity, for example by excluding electrical components, and by streamlining heating and water recycling. A disadvantage of SE8106668-0, is that heating of water for circulation takes place in an electricity-consuming manner, which in combination with energy storage, reduces the operating length before necessary charging.

[0025] A known alternative for heating water could be heat exchange with gas, which is a possibility mentioned in EP2793667. In combination with an energy storage, such heat exchange in showers circulating supplied and used water would be of particular importance. A problem and a disadvantage, is that today's flow heaters of this kind are usually not designed for the small and constant heat losses that regularly occur during shower water circulation. Instead, they are usually designed for situations where water is removed after bottling and to, as in SE510470.C2, quickly achieve higher temperatures, where for example bacterial risks are reduced. They are also not adapted for a water circulation with water purification at bacterial level, which reduces the need for high temperatures, and known showers that recycle used shower water also have a circulation circuit that does not create good conditions for lower power, regardless of whether it is heat exchange with gas or with electricity.

[0026] So-called mini showers with gas-fired flow heating do not always reach temperatures where bacterial risks are reduced and since water purification at the bacterial level is lacking, there may thus be a health issue. Another disadvantage is also that used shower water in these conventional showers is not recycled. This requires more energy for heating than when used shower water is recycled.

[0027] It therefore exists a need for an improved solution with regards to a water recirculation system for heating and cleaning of domestic water.

Summary of invention

[0028] An objective of the present invention is thus to accomplish a water recirculation system for heating and cleaning of domestic water which reduces the energy consumption.

[0029] According to one aspect, the invention concerns a water recirculation system for heating and cleaning of domestic water, comprising a casing, a water reservoir unit for containing water to be recirculated, a cleaning device for cleaning of water in the water recirculation system, a heating unit for heating of water, a water outlet unit, a pipe system for recirculation of water in the water recirculation system, a collection unit for collection of water from the water outlet unit or from an external source of water, a water pump for pumping water in the water recirculation system, a power supply cable arranged to supply electrical power to the water pump. The pipe system comprises a first and a second pipe circuit. The water recirculation system is configured to switch between a heating mode and an operational mode. In the heating mode the water is recirculated in the first pipe circuit for the water to be circulated from the water reservoir unit to the heating unit and circulated back to the water reservoir unit, for being heated until the water reaches a predetermined temperature. In the operational mode the water is recirculated in the second pipe circuit for the water to be circulated from the heating unit, ejected out through the water outlet unit for being made available for a user, further being collected by the collection unit, led to the water reservoir, circulated to the cleaning device for being cleaned, and circulated back to the heating unit for being reheated.

[0030] An advantage with the solution, is that it provides an energy efficient solution by first circulating the water to be heated in the first pipe circuit prior it reaches a predetermined temperature for then finally being ejected out through the water outlet unit for being made available for the user. This implies that the water does not need to be ejected out through the water outlet unit, and thus losing energy to the surrounding ambient, before it reaches the predetermined temperature.

[0031] The above system may be configured according to different optional embodiments. For example, the water recirculation system may further comprise an adjustable valve arranged between the heating unit and the water outlet unit for enabling switching between the heating mode and the operational mode. The water may pass through the adjustable valve for either being circulated back to the water reservoir unit or being directed to the water outlet unit.

[0032] An advantage with the solution, is that it provides a mechanical mechanism for enabling an energy efficient solution by first circulating the water to be heated in the first pipe circuit prior it reaches a predetermined temperature for then finally, passing through the adjustable valve, being ejected out through the water outlet unit for being made available for the user.

[0033] According to an embodiment of the invention, in the heating mode the water may be further recirculated through the cleaning device for being cleaned.

[0034] An advantage with the solution, is that the water during heating, prior being ejected out through the water outlet unit, could also be cleaned. This implies that polluted/untreated water could enter the system, and both being cleaned and heated in an energy efficient process. [0035] According to an embodiment of the invention, the water recirculation system may further comprise a start/stop switch for enabling a user to start/stop the water pump and the heating unit.

[0036] An advantage with the solution, is that the described energy efficient system easily could be started/stopped by a user.

[0037] According to an embodiment of the invention, the water recirculation system may further comprise a float switch arranged in the water reservoir unit for automatically connecting/disconnecting the power supply cable for starting/stopping the water pump and the heating unit when the water in the water reservoir unit has reached a certain level.

[0038] An advantage with the solution, is that the described energy efficient system easily could be started/stopped when the water in the water reservoir unit has reached a certain level.

[0039] According to an embodiment of the invention, the water recirculation system may further comprise a float valve arranged in the water reservoir unit for controlling the water supply from an external source of water.

[0040] An advantage with the solution, is that is that the water supply to the described energy efficient system could easily be automatically managed.

[0041] According to an embodiment of the invention, the cleaning device may further comprise at least one detachable filter sleeve, and at least one removable filter.

[0042] An advantage with the solution, is that the described energy efficient system could comprise removable filter components resulting in an easily maintainable system.

[0043] According to an embodiment of the invention, the water recirculation system may further comprise a drainage system, comprising a drainage inlet, a water trap, and a drainage outlet. [0044] An advantage with the solution, is that the heated water could be sent to a drainage system for it to be recirculated again within said water recirculation system at another point in time. The water could also more easily be used outside the water recirculation system by using the drainage system. The drainage system could also be arranged in such a way so that the water does not even have to be sent out in the ambient, thus preventing the water from losing energy, before entering the drainage system.

[0045] According to an embodiment of the invention, the drainage outlet may be arranged to be connected to a detachable external water reservoir.

[0046] An advantage with the solution, is that the heated water could from the water outlet unit be sent, passing through the drainage system, to a detachable external water reservoir for being recirculated again within said water recirculation system at another point in time. The water could also more easily be used outside the water recirculation system by using the external water reservoir.

[0047] According to an embodiment of the invention, the heating unit may comprise a combustion chamber with an air intake, an exhaust unit for enabling emission of exhausts from the combustion chamber, a spark plug connected to an igniter, and a gas nozzle for distributing the flow of gas into the combustion chamber. The first and the second pipe circuit may extend through or adjacent to the combustion chamber or adjacent to the exhaust unit for the water in the first and the second pipe circuit to be heated. The power supply cable may further be arranged to supply electrical power to the spark plug connected to the igniter.

[0048] An advantage with the solution, is that it provides a proven heating unit for enabling described energy efficient water recirculation system.

[0049] According to an embodiment of the invention, the heating unit may further comprise a gas distribution device comprising a plurality of additional gas nozzles for further distributing the flow of gas originating from the gas nozzle into the combustion chamber. [0050] An advantage with the solution, is that it may further enhance the heating process in the described energy efficient water recirculation system.

[0051] According to an embodiment of the invention, the water recirculation system may further be arranged to be connected to a gas pressure unit in connection to a reducing valve. The reducing valve may be connected to a solenoid valve and to said gas nozzle. The power supply cable may further be arranged to supply electrical power to the solenoid valve.

[0052] An advantage with the solution, is that it may further enhance the heating process in the described energy efficient water recirculation system.

[0053] According to an embodiment of the invention, the water recirculation system may further comprise a first water temperature sensor arranged in the first pipe circuit for collecting water temperature data. The water temperature data may be retrieved by a control unit. The control unit may be further arranged to automatically control the adjustable valve, the heating unit and the water pump, based upon the collected water temperature data.

[0054] An advantage with the solution, is that it provides means for the system to automatically control the adjustable valve.

[0055] According to an embodiment of the invention, the water recirculation system may further comprise a second water temperature sensor arranged in the second pipe circuit for collecting water temperature data. The water temperature data may be retrieved by a control unit. The control unit may further be arranged to automatically control the adjustable valve, the heating unit and the water pump, based upon the collected water temperature data.

[0056] An advantage with the solution, is that it provides additional means for the system to even better automatically control the adjustable valve.

[0057] According to an embodiment of the invention, the control unit may further be arranged to control the solenoid valve for starting/stopping the gas flow. [0058] An advantage with the solution, is that it provides additional means with regards to health and safety.

[0059] According to an embodiment of the invention, the power supply cable may further be arranged to be connected to an energy storage unit.

[0060] An advantage with the solution, is that the described energy efficient water recirculation system may be used without access to an electricity grid.

[0061] The water coming to the water reservoir and/or the collection unit can either come from an external source of water or from the water outlet unit, among others.

[0062] The detachable external water reservoir could be a rubber bladder, among others.

[0063] The water outlet unit could for instance be a shower nozzle, among others.

[0064] The water outlet unit could be detachably connected to a water outlet unit holder.

[0065] A cleaning grid could be positioned in between the collection unit and the water reservoir unit.

[0066] The first and the second pipe circuit could share some or most of their physical portions, but could also be fully physically separate from each other.

[0067] The predetermined temperature, could either be defined by a human being in real time if the system is manually controlled, or programmed into the control unit if the system is automatically controlled.

[0068] The invention could be used as a shower, and as a sink, among others.

[0069] The heating unit heats the water when the water circulates in the first pipe circuit until the desired/predetermined temperature is achieved. This could imply that the incoming water is heated by 9-25 °C. The incoming water could for instance have a temperature of 20 °C, and the temperature of the desired/predetermined could be 29 °C.

[0070] The heating of the water in the second pipe circuit compensates for the heat losses resulting from the water circulating in this circuit. The losses originate from the water passing through the different parts of the system, both internally and externally. The latter happens when the water passes out though the water outlet unit into the ambient and back to the internal system via the collection unit.

Brief description of drawings

[0071] The invention is now described, by way of example, with reference to the accompanying drawings, in which:

[0072] Fig. 1 shows a water recirculation system in a perspective view, according to an embodiment of the invention, and

[0073] Fig. 2a and 2b show a water recirculation system in schematic views, according to different embodiments of the invention, and

[0074] Fig. 3 shows a heating unit in a perspective view, according to an embodiment of the invention, and

[0075] Fig. 4 shows a water recirculation system with a drainage system and a detachable external water reservoir in a perspective view, according to an embodiment of the invention, and

[0076] Fig. 5 shows a heating unit in a side view, according to an embodiment of the invention, and

[0077] Fig. 6 shows a block diagram of a control unit, according to an embodiment of the invention.

Description of embodiments

[0078] In the following, a detailed description of a water recirculation system for heating and cleaning of domestic water, is provided. [0079] Fig. 1 shows a water recirculation system 1, according to an embodiment of the invention. The water recirculation system 1 is made up of a casing 2, a water reservoir unit 3 for containing water to be recirculated, a cleaning device 4 for cleaning of water in the water recirculation system 1, a heating unit 5 for heating of water, a water outlet unit 6, a pipe system 7 for recirculation of water in the water recirculation system 1, a collection unit 8 for collection of water from the water outlet unit 6 or from an external source of water, a water pump 9 for pumping water in the water recirculation system 1, a power supply cable 10 arranged to supply electrical power to the water pump 8. The water recirculation system 1 further comprises an adjustable valve 13 arranged between the heating unit 5 and the water outlet unit 6 for enabling switching between a heating mode and an operational mode. The water passes through the adjustable valve 13 for either being circulated back to the water reservoir unit 3 or being directed to the water outlet unit 6. The water recirculation system 1 further comprises a start/stop switch 14 for enabling a user to start/stop the water pump 9 and the heating unit 5. The water recirculation system 1 further comprises a float switch 15 arranged in the water reservoir unit 3 for automatically connecting/disconnecting the power supply cable 10 for starting/stopping the water pump 9 and the heating unit 5 when the water in the water reservoir unit 3 has reached a certain level. The water recirculation system 1 further comprises a float valve 16 arranged in the water reservoir unit 3 for controlling the water supply from an external source of water. The cleaning device 4 further comprises at least one detachable filter sleeve 17, and at least one removable filter 18. The water recirculation system 1 is further arranged to be connected to a gas pressure unit 32 in connection to a reducing valve 33. The reducing valve 33 is being connected to a solenoid valve 34 and to a gas nozzle 29 (not shown in figure). The power supply cable 10 is further arranged to supply electrical power to the solenoid valve 34. The power supply cable 10 is further arranged to be connected to an energy storage unit 39.

[0080] Fig. 2a shows a water recirculation system 1 , according to an embodiment of the invention. The pipe system 7 further comprises a first 11 and a second pipe circuit 12. The water recirculation system 1 is configured to switch between a heating mode and an operational mode, wherein in the heating mode the water is recirculated in the first pipe circuit 11 for the water to be circulated from the water reservoir unit 3 (not shown in figure) to the heating unit 5 and circulated back to the water reservoir unit 3, for being heated until the water reaches a predetermined temperature, and wherein in the operational mode the water is recirculated in the second pipe circuit 12 for the water to be circulated from the heating unit 5, ejected out through the water outlet unit 6 for being made available for a user, further being collected by the collection unit 8 (not shown in figure), led to the water reservoir 3, circulated to the cleaning device 4 for being cleaned, and circulated back to the heating unit 5 for being reheated. The water passes through the adjustable valve 13 for either being circulated back to the water reservoir unit 3 or being directed to the water outlet unit 6. The water recirculation system 1 further comprises a first water temperature sensor 35 arranged in the first pipe circuit 11 for collecting water temperature data 36 (not shown in figure). The water temperature data 36 is retrieved by a control unit 37 (not shown in figure). The control unit 37 is further arranged to automatically control the adjustable valve 13, the heating unit 5 and the water pump 9 (not shown in figure), based upon the collected water temperature data 36. The water recirculation system 1 further comprises a second water temperature sensor 38 arranged in the second pipe circuit 12 for collecting water temperature data 36. The water temperature data 36 is retrieved by a control unit 37 (not shown in figure). The control unit 37 is further arranged to automatically control the adjustable valve 13, the heating unit 5 and the water pump 9, based upon the collected water temperature data 36.

[0081] Fig. 2b shows a water recirculation system, according to an embodiment of the invention. In the heating mode the water is further recirculated through the cleaning device 4 for being cleaned.

[0082] Fig. 3 shows a heating unit 5, according to an embodiment of the invention. The heating unit 5 comprises a combustion chamber 24 with an air intake 25 (not shown in figure), an exhaust unit 26 (not shown in figure) for enabling emission of exhausts from the combustion chamber 24, a spark plug 27 connected to an igniter 28, and a gas nozzle 29 for distributing the flow of gas into the combustion chamber 24. The first 11 and the second pipe circuit 12 extend through the combustion chamber 24 for the water in the first 11 and the second pipe circuit 12 to be heated. The power supply cable 10 is further arranged to supply electrical power to the spark plug 27 connected to the igniter 28. The heating unit 5 further comprises a gas distribution device 30 comprising a plurality of additional gas nozzles 31 for further distributing the flow of gas originating from the gas nozzle 29 into the combustion chamber 24.

[0083] Fig. 4 shows a water recirculation system 1, according to an embodiment of the invention. The water recirculation system 1 further comprises a drainage system 19, comprising a drainage inlet 20, a water trap 21, and a drainage outlet 22. The drainage outlet 22 is arranged to be connected to a detachable external water reservoir 23.

[0084] Fig. 5 shows a heating unit 5, according to an embodiment of the invention. The heating unit 5 comprises a combustion chamber 24 with an air intake 25, an exhaust unit 26 for enabling emission of exhausts from the combustion chamber 24, and a gas nozzle 29 for distributing the flow of gas into the combustion chamber 24. The first 11 and the second pipe circuit 12 extend adjacent to the exhaust unit 26 for the water in the first 11 and the second pipe circuit 12 to be heated.

[0085] Fig. 6 shows a control unit 37, according to an embodiment of the invention. The control unit 37 comprises a processor 37. d, a user interface 37. b, a memory 37. a, and communication gateways 37. c. Through the communication gateways the control unit can receive and send signals from/to other parts of the system. Through the user interface the control unit can communicate with the user, through for instance a viewing screen, keyboard, mouse, printer, loud speaker, microphone or other type of peripheral. A computer program product can be stored in the memory, and be executed in the processor. LIST OF COMPONENTS = water recirculation system = casing = water reservoir unit = cleaning device = heating unit = water outlet unit = pipe system = collection unit = water pump = power supply cable = first pipe circuit = second pipe circuit = adjustable valve = start/stop switch = float switch = float valve = detachable filter sleeve = removable filter = drainage system = drainage inlet = water trap = drainage outlet = detachable external water reservoir = combustion chamber = air intake = exhaust unit = spark plug = igniter = gas nozzle = gas distribution device = plurality of additional gas nozzles = gas pressure unit = reducing valve = solenoid valve = first water temperature sensor = water temperature data = control unit = second water temperature sensor = energy storage unit

Claims

1. A water recirculation system (1 ) for heating and cleaning of domestic water, comprising a casing (2), a water reservoir unit (3) for containing water to be recirculated, a cleaning device (4) for cleaning of water in the water recirculation system (1), a heating unit (5) for heating of water, a water outlet unit (6), a pipe system (7) for recirculation of water in the water recirculation system (1), a collection unit (8) for collection of water from the water outlet unit (6) or from an external source of water, a water pump (9) for pumping water in the water recirculation system (1), a power supply cable (10) arranged to supply electrical power to the water pump (8), wherein the pipe system (7) comprises a first (11) and a second pipe circuit (12), wherein the water recirculation system (1) is configured to switch between a heating mode and an operational mode, wherein in the heating mode the water is recirculated in the first pipe circuit (11 ) for the water to be circulated from the water reservoir unit (3) to the heating unit (5) and circulated back to the water reservoir unit (3), for being heated until the water reaches a predetermined temperature, and wherein in the operational mode the water is recirculated in the second pipe circuit (12) for the water to be circulated from the heating unit (5), ejected out through the water outlet unit (6) for being made available for a user, further being collected by the collection unit (8), led to the water reservoir (3), circulated to the cleaning device (4) for being cleaned, and circulated back to the heating unit (5) for being reheated.

2. Water recirculation system (1) according to claim 1, wherein the water recirculation system (1) further comprises an adjustable valve (13) arranged between the heating unit (5) and the water outlet unit (6) for enabling switching between the heating mode and the operational mode, wherein the water passes through the adjustable valve (13) for either being circulated back to the water reservoir unit (3) or being directed to the water outlet unit (6).

3. Water recirculation system (1) according to any of the preceding claims, wherein in the heating mode the water is further recirculated through the cleaning device (4) for being cleaned.

4. Water recirculation system (1) according to any of the preceding claims, wherein the water recirculation system (1) further comprises a start/stop switch (14) for enabling a user to start/stop the water pump (9) and the heating unit (5).

5. Water recirculation system (1) according to claim 1-3, wherein the water recirculation system (1) further comprises a float switch (15) arranged in the water reservoir unit (3) for automatically connecting/disconnecting the power supply cable (10) for starting/stopping the water pump (9) and the heating unit (5) when the water in the water reservoir unit (3) has reached a certain level.

6. Water recirculation system (1) according to any of the preceding claims, wherein the water recirculation system (1) further comprises a float valve (16) arranged in the water reservoir unit (3) for controlling the water supply from an external source of water.

7. Water recirculation system (1) according to any of the preceding claims, wherein the cleaning device (4) further comprises at least one detachable filter sleeve (17), and at least one removable filter (18).

8. Water recirculation system (1) according to any of the preceding claims, wherein the water recirculation system (1) further comprises a drainage system (19), comprising a drainage inlet (20), a water trap (21), and a drainage outlet (22).

9. Water recirculation system (1) according to claim (8), wherein the drainage outlet (22) is arranged to be connected to a detachable external water reservoir (23).

10. Water recirculation system (1) according to any of the preceding claims, wherein the heating unit (5) comprises a combustion chamber (24) with an air intake (25), an exhaust unit (26) for enabling emission of exhausts from the combustion chamber (24), a spark plug (27) connected to an igniter (28), and a gas nozzle (29) for distributing the flow of gas into the combustion chamber (24), wherein the first (11) and the second pipe circuit (12) extend through or adjacent to the combustion chamber (24) or adjacent to the exhaust unit (26) for the water in the first (11) and the second pipe circuit (12) to be heated, and wherein the power supply cable (10) is further arranged to supply electrical power to the spark plug (27) connected to the igniter (28).

11. Water recirculation system (1) according to claim 10, wherein the heating unit (5) further comprises a gas distribution device (30) comprising a plurality of additional gas nozzles (31) for further distributing the flow of gas originating from the gas nozzle (29) into the combustion chamber (24).

12. Water recirculation system (1) according to claim 10 or 11, wherein the water recirculation system (1) is further arranged to be connected to a gas pressure unit (32) in connection to a reducing valve (33), wherein the reducing valve (33) is being connected to a solenoid valve (34) and to said gas nozzle (29), wherein the power supply cable (10) is further arranged to supply electrical power to the solenoid valve (34).

13. Water recirculation system (1) according to any of the preceding claims, wherein the water recirculation system (1) further comprises a first water temperature sensor (35) arranged in the first pipe circuit (11) for collecting water temperature data (36), wherein the water temperature data (36) is retrieved by a control unit (37), and wherein the control unit (37) is further arranged to automatically control the adjustable valve (13), the heating unit (5) and the water pump (9), based upon the collected water temperature data (36).

14. Water recirculation system (1) according to any of the preceding claims, wherein the water recirculation system (1) further comprises a second water temperature sensor (38) arranged in the second pipe circuit (12) for collecting water temperature data (36), wherein the water temperature data (36) is retrieved by a control unit (37), and wherein the control unit (37) is further arranged to automatically control the adjustable valve (13), the heating unit (5) and the water pump (9), based upon the collected water temperature data (36).

15. Water recirculation system (1) according to claim 12 and 13 or 12 and 14, wherein the control unit (37) is further arranged to control the solenoid valve (34) for starting/stopping the gas flow.

16. Water recirculation system (1) according to any of the preceding claims, wherein the power supply cable (10) is further arranged to be connected to an energy storage unit (39).