DESCRIPTION

The last years, many methods and products that ensure the supply of hot water in residential buildings or facilities, have been developed. The heating of water is achieved either by burning fossil fuels, either by electricity or renewable energy.

The existing hot water supply methods correspond to simple network without recirculation or recirculation network.

In the case of a network without recirculation, at rest, the water in the pipes of the hot branch remains cold or warm, depending on the time elapsed from the last time the user desired hot water. Even insulated hot water pipes eliminate heat, and eventually the water and the tubes acquire the ambient temperature. When the user opens the tap, desiring hot water, the hot pipeline system should be completely empty by the cold water and filled with hot water coming from the heating source. The delay in the arrival of hot water, causes great waste, since every time the user wants hot water, many liters of clean water are eliminated. Also, apart from cold water, hot water ends up in drains too, as the time of its arrival at the tap cannot be controlled or estimated.

In the case of recirculation, this is achieved either by using pipeline systems for the return of water to the heating source, or by returning from the cold pipeline system. In both cases, a pump forces the water in recirculation. Hot water pipe through additional pipelines communicates and returns the hot water to the heating source. In this case an installation of the return network is needed which should have been done from the beginning of construction. That means extra cost for materials and labor. If research hadn't been conducted during the original construction of the water network, the subsequent installation would be very difficult because costly interventions in building and construction have to be made. Most buildings in the world have this recirculation system. If there is no good insulation to the network of branches of hot water and back, then there's unnecessary energy consumption in the form of heat loss that is eliminated from the tube into the environment, as well as electricity consumption for the operation of the pump. Also, there are thermal losses, since water should be released throughout the network installation. Another drawback of this technology is that the return pipe reaches to the end of each branch, so whenever how water is desired, independent of the position of the tap in connection with the heating source, water is sent over the entire length of the pipelines up to the furthest faucet. Finally, if it is desirable that the pump works only when necessary, electrical installations for activation and deactivation are required. The above method is economically advantageous to hotels and general facilities that serve large numbers of people and where use is permanent.

There are different approaches to the issue without the usage of a third branch. An alternative is, to mount a pump in every faucet which will recirculate water only for this particular faucet. However, a drawback of this method is that we need a pump for every faucet and space underneath in order to place the pump, something that is not always possible. Another condition, is the availability of power supply under the faucet.

In addition, there are thermostatic jumpers placed under the faucet so water recirculation is achieved with remote pump, but the disadvantage of this method is than the pumps operate on a timer that is adjusted by the user, which means that many times they work unnecessarily when the user is out of the space and also recirculate hot water in all branches of the house and not only to the faucet that is being used. Those thermostatic jumpers have the disadvantage that they allow, due to insufficient sealing, the hot water to flow in the cold branch and many times it results to the hot water ejecting from both branches.

From US 4 554 688 is known a provision which provides for each tube of hot water and an extra branch that directs water into the heating source since a temperature drop is noted. The recirculation systems uses a valve, a sensor, a pump etc. This layout presents increased heat losses to the environment as the tubes are always hot, while the pump operation is causing increased energy consumption. Furthermore, this provision cannot be applied to existing hot water supply facilities, since modifications of the existing network with the introduction of new pipes, are required, which are costly if the network is already built.

The US 5 261 443 is a provision that while water is recirculating in a similar way as the previous, it makes use of electrical components such as electric valves and electric pump activation sensors, while a temperature sensor is mounted on each faucet. The downside of this provision is the existence of electrical wiring and voltage parts in places of high- water vapor such as shower, faucets etc. which is dangerous in case of a leakage current. In addition, the introduction of power cables in such places is practically difficult and costly in an existing building.

The US 2009/021 1644 Al provides a recirculation system which at each hot water endpoint has an electric jumper which allows the flow of water from the hot branch into the heating source across the cold branch. The recirculation starts with the help of a logical programming that is programmed by the user to operate at predetermined times of the day. The particular layout, presents particular complexity because of the many sensors and electrical components while many cables are in places where humidity is, which as mentioned above, is dangerous. Also, the logical circuit applied, does not identifies the needs of the user all the time.

The patent EP 2 554 919 Al claims that, for each faucet there is an add-on recirculation device. When the user requests hot water, the mechanism starts the recirculation of water by the time the hot water reaches the tap, when it starts to flow. The main disadvantage of this layout is the high costs, since in each of the endpoints of the hot water network, a pump must be placed along with sensors to control its operation. Another main disadvantage is that the user must be close to the tap to control the flow, while the volume of the necessary items of this particular construction makes it impossible to hide. To US 7 475 703 B2 provides an array of water recirculation, positioned near the tap which is using a thermostatic valve which bridges the branches of hot and cold water by activating or deactivating the recirculation. The disadvantage of this layout is that the thermostat works automatically without user activation. In the case of one faucet the recirculation is functioning successfully, but in the case where more faucets are added in the layout, the invention does not return the expected, as the placement of the faucets in a network is in parallel and thus of every faucet with a recirculation device only a subdivision of the initial supply of the pump is passing by. In addition, the water which at the beginning of the recirculating is running through the cold pipes, presents thermal losses due to heat exchange among the pipes and so the valve allows the passage of warm water to the cold branch until the thermostat is activated and interrupts the flow.

At this point we must underline that the main challenge when creating a water recirculation system, is a system of control that would properly inform the controller of the pump, about the desires of users and the network status.

With this invention are achieved:

1 . High level of comfort during use of the invention.

2. Economy in water consumption with zero losses.

3. Using a single pump for all network taps.

4. The recirculation of the hot water is happening only the moment that this is desirable, limiting thereby the thermal losses from unnecessary recirculation

5. The water flows only to the faucet that the user is using, without passing

through any other tubing and thus warms the minimum possible length of piping

6. The pump functions long enough until the hot water to reaches the faucet and then stops automatically, reducing to a minimum the electricity consumption.

7. Minimize wiring length as the water serves as means of information

transmission

8. Mounting of the Thermostatic Recirculation Valve over, through or very near the faucet because of its small size.

9. Reduction of installation cost of recirculation system due to the removal of the extra branch of hot water used for its returning.

10. System reliability due to usage of a minimum number of sensors

11. Installation in any installation even in existing networks without aesthetic and functional discomfort

12. Installation possibility by low-skilled people

13. Creation of a new type of pump's casing which integrates all necessary pipes and sensors in order to reduce the size of the system

The invention is a system that contains three innovative subsystems that cooperate with each other and work in tandem so that the final system gathers all the advantages of competing systems without disadvantages.

The invention is characterized by the fact that achieves the bridging of cold and hot water in an original way, using specially designed jumper - switches, called Thermostatic Recirculation Valves. Specifically, bridging takes place as close as possible to the faucet even within this with specially mixing plates. At the same time, an intelligent system (Controller) of water recirculation understands the values of the sensors and activates or deactivates the pump, reducing to the minimum the run time. In particular, the principle of operation of this invention is based on pressure difference between hot and cold sector, values obtained from properly mounted pressure sensors and transferred to the controller.

The first point which our invention takes precedence over the others is the introduction of Thermostatic Recirculation Valve, which is activated by the user when there is a desire for hot water. This valve allows the water flow through, between the two branches resulting in bridging them.

The advantage of the invention is that the small size of the Thermostatic Recirculation Valve (or TRV) , allows it to be placed inside a faucet cartridge, to replace the existing mechanism so as to achieve recirculation with an additional movement of the lever. This movement is shifting the lever down which causes the bridging of two branches, resulting in initiation of recirculating. When the hot water reaches the faucet, it activates the thermostat in the valve, the bridge of the two branches is suspended and the tap lever automatically returns to its original position. Resetting the lever to its original position indicates that the hot water is ready to use. In existing networks that there is a weakness to position such a device, an alternative design of the valve permits the fitting at the base of the faucet or close it.

The second point is to inform the controller for the pump to activate or deactivate, respectively. Unlike other patents that seek recirculation, ours does not use wires or wireless transmitters that carry electrical signals to inform the controller, but the pressure and water flow are used as information transmitters. For this purpose, the branch of hot water following the heat source, acquires with an appropriate device, higher pressure compared to the cold. Consequently, any change in the status of the network is perceived by sensors leading the controller to the corresponding function.

Below, the invention is explained in great detail on the basis in conjunction with multiple figures. These shows:

Fig. 1 : Total recirculation and rapid supply system of hot water in house

Fig. 2: an illustration of the overall structure of the thermostatic recirculation valve of a particular type to help understand the basic principle

Fig. 3: an illustration of one side of the plate of the thermostatic valve recirculation illustrated in Figure 2

Fig. 4: an illustration of the other side of the plate of the TRV illustrated in Figure 3 Fig. 5: an illustration of the face of the second plate of the TRV illustrated in Figure 2 Fig. 6: an illustration of the TRV of Figure 2 in shell

Fig. 7: an illustration of components of a TRV built in a faucet mixing cartridge

Fig. 8: an illustration of the bottom plate of the TRV incorporated in a faucet mixing cartridge shown in Figure 7 Fig. 9: a representation of the rear face of the bottom plate of the TRV incorporated in a faucet mixing cartridge shown in Figure 7

Fig. 10: an illustration of the middle plate of the TRV incorporated in a faucet mixing cartridge shown in Figure 7

Fig. 11 : an illustration of the back side of the middle plate of the TRV incorporated in a faucet mixing cartridge shown in Figure 7

Fig. 12: illustration of a top plate of the TRV incorporated in a faucet mixing cartridge shown in Figure 7

Fig. 13: an illustration of the back face of the top plate of the TRV incorporated in a faucet mixing cartridge shown in Figure 7

Fig. 14: an illustration of the positioning of the mechanism of TRV, shown in Figure 2, at the base of the faucet.

Fig. 15: an illustration of the positioning of the mechanism of TRV, shown in Figure 2, placed close to the faucet.

Fig. 16: an illustration of the additional movement of a faucet which contains the TRV, shown in Figure 7

Fig. 17: an illustration of the TRV mechanism using bimetallic strip and pin as faucet mixing cartridge

Fig. 18: an illustration of the bottom plate of TRV using bimetallic strip and pin as faucet mixing cartridge

Fig. 19: an illustration of the function of the TRV mechanism using bimetallic strip and pin as faucet mixing cartridge

Fig. 20: an illustration of the bimetallic strip shape used in the TRV pictured in Figure 17 Fig. 21 : a view of the wall-mounted device of the TRV, shown in Figure 2 within the faucet

Fig. 22: an illustration of a bottom view of the wall-mounted TRV, shown in Figure 2 within the faucet

Fig. 23: an illustration of the system and its components, incorporated into a new type of pump casing

Fig. 24: an illustration of the system with the new type of pump casing

Fig. 25: an illustration of the body of the shaped pump casing

Fig. 26: an illustration of the body of the shaped pump casing with the components that compose

Fig. 27: an illustration of the overall pump system, with the shaped casing, the rotor and the motor

Fig. 28: an illustration of the controller used in controlling the system

In Figure 1 is illustrated the recirculation embodiment of our invention [1001]. More specifically, the supply of water from the city network [130] carrying cold water, is branching into two pipes [130a] and [130b]. The [130a] pipe transfers the cold water inside the heat source [132] where the water temperature is rising and eventually hot water ejects the heating source. Following the figure, the recirculation mechanism [1002] is illustrated which includes a parallel branch [109a] composed of a non-return valve [133a] in series with a pump [134] and an expansion tank [135h]. The branch [109a] includes a pressure sensor [136H]. The positioning of the non-return valve [133a] &

[133b] permits water passage only in the direction of exit and not vice versa. Upon exiting the loop, a flow sensor [137H] follows, while pipe [109] ends up to the system [1003] i.e. the Thermostatic Recirculation Valve [1115] and the faucet [110]. Finally, flow [137C], pressure [13Cc] and temperature [138C] sensors are placed in the pipe [130b] which carries cold water to the TRV [1115] and the faucet [1 10]. All sensors send information to the controller [139] that enables or disables the pump [134]. This system is constructed such that the water located in the piping after the non-return valves [133] up to the faucet(s) [1 10] having an increased pressure relative to the cold branch [130b]. For the increase and maintenance of the pressure the pump [134] which is activated by the controller's commands [139], acquiring information from the pressure sensors [136H] & [136C].

Figure 2 shows the components and their connection of a TRV [11 15] describing the basic principle of this assembly. TRV consists of three parts: two special designed plates [101], [106] and a thermostat [105]. When the plates are in the closed position (position A), the passage of water through the TRV is prevented. The top plate [106] in the closed position prevents the flow of water as the specific holes [102] and [104] (holes) of the lower plate, are positioned relatively to the upper plate in order to become an obstacle and prevents water flow. The flow activation is accomplished by moving the upper plate [106] along the bottom [101], leading the holes, which in the closed position sealed the water flow, to permit water enter the [107]. The pressure of the water entering from the hole, corresponding to the hot branch, leads to water flowing through the body of the thermostat [105], and out of the other hole resulting in recirculation in the network. When the water temperature reaches the temperature activation levels of the thermostat, its pin, due to thermal expansion of thermostat's content, is pushed out. Because the thermostat is seated [105] to the bottom plate [101 ], its pin pushes and moves the top plate [106] back to its original position resulting to the interruption of the water flow. The movement caused by the piston is equal to the difference of the two plates in length. The material used for these plates [101], [106] is ceramic or other material with similar mechanical properties in order to achieve hermetic seal.

The TRV [1 115] which simulates a faucet mixing cartridge, is surrounded by a cell [200] which connects the pipes of the two water branches and hermetically seals the valve mechanism using sealing rings.

In Figure 3 is illustrated the geometry of the bottom plate [101] of the TRV cartridge, which includes inlets of small cross sections of the two water branches [102] and [104] and also has an appropriate geometry gap [103] in order to mount the thermostat [105] in such a way it cannot move in relation to it.

Figure 4 illustrates the geometry of the other face of the plate [101] that has inlets corresponding to the two water branches [102], and [104].

Figure 5 illustrates the geometry of the upper plate [106] of the TRV basic design.

Figure 6 shows a cross section of the TRV [1115] showed in Figure 2 with its cell [200] which is the base of connection of the main pipes. A lever [199] which moves the top plate [106] along the lower [101] is located in a special designed pocket in the cell body. Furthermore, the top plate [106] is smaller in area than the lower [101] and can be moved longitudinally relative to the former plate. The [106], has a pocket of [107] particular geometry which surrounds externally the thermostat body which exceeds the margins of the bottom plate, preventing, finally in this way, any vertical displacement.

Figure 7 shows the connection of a TRV [11 15b] incorporated inside a faucet which replaces the faucet mixing cartridges. This mechanism is consisted now by three components with special geometries, the ceramic plates 115a, 115b and 115c.

The mechanism of TRV [1 1 15b], replaces the pre-installed faucet mixing cartridge and performs the task of mixing, bridging and recirculating of the water. Therefore, the size of the mixing plates and their geometry is proportional to the size and the geometry of the faucet. The operation of the mentioned TRV is based on the existing method of water mixing inside a mixing cartridge, with the difference of the modification of the middle plate [115b] and the prosthesis of an upper mixing plate [115c]. The bottom mixing plate [115a] is stable with no degree of freedom. The middle plate [115b], which is smaller than the others, executes, except translational movement along plates [115a] and [1 15c], rotational movement, too, about its axis in cooperation with plate [115c], when moving the faucet's handle 110c, as illustrated in Figure 16 [129] .The degrees of freedom of the middle plate [1 15b] are defined as two. The upper plate [115c] has one degree of freedom as it rotates together with the [115b].

These plates are preferably ceramic with a specific surface area in order to seal tightly, thereby entrapping the water and preventing its exit from the body.

To avoid stress conditions and leakage, the mixing plates are manufactured by more resilient materials (possibility of changing its volume due to changes in pressure) in order to absorb the contraction - expansion of the system.

In the following Figures 8 and 9 illustrate the geometry of the different faces of the plate [1 15a]. More specifically, the bottom plate [115a] bears piping slots [116], [1 17] of hot and cold branch. This configuration forces the water to pass from slots of smaller cross section.

In Figures 10 and 11, the geometry of the different sides of the middle plate [1 15b], is illustrated. The middle plate [1 15b], consists of two completely smooth sides. The view of Figure 10 touches the bottom plate [115a] and allows through the holes [116], [117] and [1 19] the mixing of hot and cold water at a position where the faucet is open and permits flow. In the position where the faucet is closed, the slot [1 19] ceases to cooperate with the bottom plate [115a] and the water doesn't mix and doesn't flow. The view of Figure 1 1 of the plate [115b] is a special design plate where a slot based on thermostat's geometry [123], is designed. The thermostat is mounted to that slot. Moreover, the slot has waterways [122], allowing the water to surround the thermostat externally, activating its function.

In Figures 12 and 13, the geometry of the different faces of the upper plate [1 15c], is illustrated. The upper plate [1 15c] comprises a cavity [124], which houses the rest of the thermostat and a small volume of water, introduced in order to activate the thermostat. Figure 14 depicts the installed TRV [1115a] on faucet basis [1 10a], This position is one of the suggested sites, in which 1 la5a may be introduced. As illustrated in the figure, the hot [109] and cold branch [130b] are joined to the valve body.

Figure 15 shows the mounted TRV [1115a] close to the faucet [110b] and specifically to a place under the faucet where the two braches [ 109] and [ 130b] are bridged.

Figure 16 illustrates the body of faucet [110c] and its lever movement range [125] after the modification and addition of the internal TRV [1 1 15c] which replaces the faucet mixing cartridge. The faucet, acquires a new function the one of the recirculation, which is triggered by a new movement performed by the lever .The downwards move of faucet's level [129] , the opposite movement of level which increases the flow [128]. To perform this movement, the lever must be in the middle of the route from right to left. Figure 17 illustrates the connection of a TRV [11 15c] corresponding to several parts. More specifically, sectional view A- A is illustrated. To be more accurate, the valve comprises a shaft [140], the top plate [144], the bimetallic coil strip [143], the lower plate [145], the axis sealing ring [141] and at the end the plate's sealing ring [146]. The whole structure is incorporated within housing [201]. Activation of the TRV [1 115c] is made by the user by rotation of the shaft [140]. In the initial rest position, the top plate [144] seals the holes [151] [152] located in the bottom plate [145] and so there is no leakage. When the user activates the TRV [1 115c], the shaft's rotation [140], will bring in line the holes [149] [150] of the upper plate [144] , with the holes [151] [152] of lower plate [145] and leading and permitting the bridging of hot water pipe [109] and the cold pipe [130b]. The water will pass through the tube of hot water [109] through the hole [151] which is located on the bottom plate [145]. Due to the bridging of the top plate [144], which has a hole [149], the water will fill the space that the bimetallic plate is [143], and will eject by the hole [150] in the top plate [144], Continuing, the water will flow through the hole [152], on the bottom plate [145] and will run inside the cold water pipe [130b]. When the hot water comes into contact with the bimetallic spiral strip [143] which is adapted to the axis [140], due to its properties, it will expand and thus there will be rotation of the shaft [140], thereby returning to the initial rest position. In this way and with appropriate signs (visual, audio or other), the user will be informed of the arrival of hot water on faucet. To avoid stress conditions of the materials, a resilient material (possibility of changing its volume due to changes in pressure, i.e., material containing entrapped gas bubbles in the mass), is used, in order to absorb the contraction - expansion of the system.

Figure 18 illustrates the geometry of the bottom plate bearing the holes [151] and [152] Figure 19 illustrates the inside of the TRV [1115c] and the way it operates.

In Figure 20 is shown the bimetallic strip [143] located within 1 1 15c of Figure 17.

Figure 21 and 22 illustrate the TRV [1 115a] in the form of a wall mounted faucet [1 10d]. The affixing can be done, as mentioned above, on the wall and particularly in the back of the faucet [1 10d]. The operation of the TRV [1115a] is the same as the case of Figure 7. The basic difference is, its positioning inside a specific modulated component [149].

Figure 23 illustrates a striping track system [160] and parts thereof longer incorporated into a specially designed pump shell with the rotor integration and assembly in the motor replaces the device [160]

Figure 24 shows the new type of pump impeller housing [160] that contains cavities that represent the branches of the loop of Figure 23 [109a].

Figures 25 and 26 illustrate, in more detail, the new type of pump impeller housing [160] in various views. The said shell, comprises by cavities that represent and replace the branches of the loop of Figure 13 A [109a]. In addition, it contains, internally, an expansion tank [135th], non-return valves [133a, 133b], suitably arranged pressure [136] and flow [137a] & [137b] sensors.

Figure 27 illustrates the assembly of the pump as a whole, with the shaped casing [160], the rotor [161 ] and the motor [162] which may be used.

Figure 28 shows the 1004 system, corresponding to the controller [149] which carries signal inputs and an output, for activating or deactivating the pump.

In this section it is useful to make extensive reference to the manner and the logic with which recirculation system depicted in Figure 1 .

[0001 ] Originally, and as the system under calm, flow sensors [137Ha], [137Hb] &

[137C], read zero flow in the pipes. The pressure sensors [136] measure pressure in the hot and cold branch and send the information to the controller [139]. If the controller [139] reads that the pressure of the hot [109] and cold [131b] branch is equal, then it sends a signal to the pump to activate and to increase the pressure of the hot pipeline network [109]. The pump causes pressure increase, resulting water entering the expansion tank [135th]. Then the pump stops [134] and the non-return valve [133a] & [133b] (or electric-valve or other), seals tightly and prevents water leaking back to the heating source. This situation, where the water in the pipes is limited among the non-return valves [133a] & [133b], the expansion tank [135th], the faucets [110] and the TRV

[1115] with the hot pipeline network's pressure greater than the cold one, is the point of readiness (stand by). Based on the state of readiness, we mention the possible events that divert the network from this situation.

[0002] In case, the user activates the TRV [1 115], the expansion tanks [135th] and

[135C] tend to acquire the same pressure due to bridging and so the water is forced to flow through the TRV [1115] passing from [135H] to [135C], until the pressure is equalized . The pressure sensors [136H] & [136C], and flow [137H] & [137C] send signals of the corresponding values in the controller [139] , which activates the pump [134] for water recirculation. If the temperature reaches the thermostat's activation value [105] then he turns off the short circuit and after the controller reads that the pressure of the hot branch is greater than the cold one it disables the pump. The expansion tank 136C has a different volume from the 135H

[0003] In case when a faucet [110] (or more) is activated, only in the warm sector, then the pressure of the expansion tank [135H] will be released in the form of water flow from the faucet (s). After the decompression of the tank [135H] the pressure on the hot branch will decrease, and reach a value lower than the pressure of the public network resulting in the non-return [1 13b] to allow the flow from the public network. Simultaneously, the hot branch's flow sensors [137Ha] & [137Hb] send the new values to the controller. As long as the controller receives measurements of flow indication by the flow sensors [137H] it doesn't activate the pump [134]. When the user closes the faucet/s [1 10], the flow will be reset and the pressure will the same as the grid, which return the system in situation [0001].

[0004] In case where faucet [110] (or more) is activated, only in the cold sector, then the flow will be carried out only in the cold branch [130b]. Pressure sensors [136C] and [137C] flow of cold branch measure changes in flow values. By closing he faucet, the flow is nullified and the system returns in the condition of readiness [0001].

[0005] In case where hot and cold water flow to one or more faucets is activated simultaneously, then the pressure of both branches of the system decreases and flow is observed. The operation of the pump is put on hold and the branches will operate based on cases [0003] & [0004] respectively. The software has all the adequate solutions on all possible scenarios of changes that can occur in the network, and can stand out each case in order to find the optimal solution and to enable or disable the pump accordingly and adjust pump's rotation velocity.