WO2013187750A1

WO2013187750A1 - Water heater activated by temperature change

Info

Publication number: WO2013187750A1
Application number: PCT/MX2013/000073
Authority: WO
Inventors: Luis Ignacio RAMOS DEL BOSQUE
Original assignee: Ramos Del Bosque Luis Ignacio
Priority date: 2012-06-15
Filing date: 2013-06-14
Publication date: 2013-12-19
Also published as: MX337882B; MX2012006984A

Abstract

The invention relates to a water heater activated by a temperature change of the water, detected by a temperature sensor. The heater consists of: a cold water inflow tube; a hot water outflow tube; a heat collector; a tube which is coiled around the heat collector in a single direction, has a first end and a second end, and is connected to the cold water inflow tube by its first end; a heat exchanger that has an inlet and an outlet and is connected, by the inlet thereof, to the second end of the coiled tube and, by the outlet thereof, to the hot water outflow tube, such that the inflow tube, the outflow tube, the coiled tube and the heat exchanger define a water flow pipe; the above-mentioned temperature sensor connected to a regulating mechanism and located in any part of the water flow pipe; a heat source concentric to the heat collector; and an activator connected to the heat source and to the temperature sensor.

Description

WATER HEATER ACTIVATED BY CHANGE OF TEMPERATURE

TECHNICAL FIELD OF THE INVENTION

The present invention is. refers to a water heater, in particular, refers to a low pressure water heater, whose operation on and off, is detecting a temperature change of the water flowing through the interior of the heater.

BACKGROUND OF THE INVENTION

There are currently three types of water heaters that result from the source of energy they use, whether it is energy derived from gas, electrical energy or solar energy.

Since the cost of electric power is higher, water heaters that operate under this energy are unattractive to the consumer compared to gas-operated water heaters. On the other hand, water heaters that operate with solar energy turn out to have a high initial cost in the required facilities, as well as due to their size and complexity it makes it an ineffective alternative.

That is why the most used water heater is that of gas, of which there are basically two types: traditional tank heaters and continuous flow passage heaters. Despite its wide acceptance, the tank heater is less efficient, since it consumes a greater amount of gas to keep the water hot because its operation is based on heating the water contained in its tank.

There are tank-type water heaters with capacities of up to 200 liters, this capacity being recommended by their manufacturers for room houses where more than 5 people live, so it is evident that the enormous amount of energy required to heat and keep the water at a considerable temperature 24 hours a day, 365 days a year, emitting large amounts of pollutants into the atmosphere for each room house.

This tank-type water heater has a thermostat valve that is responsible for opening the gas flow to a burner to ignite the flame that heats the cold water contained in its tank, and that when the water reaches a certain temperature the thermostat valve It closes the gas flow, thus extinguishing the burner flame.

The tank-type water heater has the disadvantage that the hot water contained in its tank may not be used completely so it cools and therefore the gas burner flame ignites again, and if the water heated in the same way it is not used, it will cool again and the gas burner flame is ignited again, and so this cycle is repeated continuously causing unnecessary expenses. This type of action results in a waste of gas, as the flame of the gas burner is turning on and off how many times the hot water decreases its temperature. US Patent Document US-7,000,847 by Andrés Guevara shows a tank type water heater that is called a "fast recovery passage" that has a small tank, a water inlet, a water outlet, a thermostat valve, a temperature sensor, a drain tap and a capsule where the temperature sensor is located among other things. This heater works with the temperature difference, that is, when the water inside the capsule is cold, the thermostat valve allows the flow of gas to ignite a flame in a gas burner. This tank type water heater has the design of a capsule where there is a water stagnation, that is, the water does not flow constantly inside the capsule, which delays the response time to open or close the thermostat valve. gas to turn the burner on or off.

On the other hand, there are the passage water heaters, either continuous or instantaneous flow.

This type of instantaneous water heaters, usually operate at high pressure of water supply, and its operation is based on the detection of differential pressure, that is, it has pressure sensors inside to detect that there are water flow due to the opening of some hot water tap, and with this automatically ignite the flame to heat the water circulating in the heater coil. The supply pressure of the water inside the heater is very often supplied by external pressure generating equipment, or with the implementation of special installations where the water supply for the heater must be placed at least 1 meter above water discharge from the heater. US Patent 4,550,689 to Gerry Wolter describes a passage water heater composed of a plurality of coils, a plurality of gas burners, an electric solenoid valve to allow and restrict the passage of gas to the burners, a restriction valve of flow, an optical sensor, a thermal switch for overheating and an electronic ignition circuit. When the hot water tap is opened there is a pressure drop inside the water pipe of the passage water heater, the pressure drop is detected by a switch, the switch activates the solenoid valve thus allowing the passage of the gas flow towards the burners, at the same time the electronic ignition circuit is activated, which has the function of igniting the gas-air mixture that leaves through the gas burner. The optical sensor has the function of keeping the solenoid valve open, as long as the gas-air mixture is on, otherwise the sensor sends a signal to the solenoid valve and the solenoid valve goes to the closed position. If there is an overheating of the water inside the water heater, the thermal switch sends a signal to the solenoid valve, where the solenoid valve goes to the closed position, thus preventing the passage of the gas flow. The electronic circuit of this gas heater requires a battery to operate.

US Patent No. 4,624,219 to Alan B. McCorquodale describes a water heater of the passage type composed of a plurality of circular coils, a lower head, a top head, a temperature sensor, a thermostat valve and a burner of gas among other things. The lower ends of these coils are connected to the lower head which is where cold water enters, the other end of the coils is connected to the upper head where the temperature sensor is housed which in turn It is connected to the thermostat valve. The operation of this heater is such that the sensor sends a signal to the thermostat valve and allows the flow of gas to the gas burner, which happens when the water is cold.

According to US Patent No. 4,624,219 a head 42, three coils 36,38 and 40, and a hot water outlet 46 can be seen in its figure. According to this configuration there is a stagnation of hot water in the upper head, particularly in the area where the temperature sensor is located, which causes the sensor reading not to be that of the water flowing to the heater outlet, but the temperature of the water that is static in a certain area of the head .

This type of water stagnation causes the sensor readings to measure the temperature of the stagnant water and not that of the water that is flowing through the heater, and consequently an unnecessary gas expense.

Another of the disadvantages of this water heater configuration is the continuous on and off of the gas burner flame, because when the hot water tap is closed, the water remains inside the heater, and when the water loses temperature, the sensor sends a signal to the thermostat valve and lets in the gas flow that feeds the gas burner flame, when the water temperature is high enough the sensor sends a signal to the thermostat valve and closes the gas flow.

This thermal cycle of cold-heat heat-cold causes, apart from unnecessary fuel costs, damage to the physical structure of the heater. Mexican patent application document MXPA05011687A by Adolfo López shows a water heater of the tank type similar to that described in previous paragraphs, in particular US patent US-7,000,847 by Andrés Guevara.

The water heater of the Mexican patent application MXPA05011687A shows a change in the location of the temperature sensor and the thermostat, which are located near the cold water inlet, without giving any other technical data of the configuration and / or the operation of the sensor inside the heater.

In view of the above, it is necessary to offer a water heater that operates at low water supply pressure and under the determination of a temperature change therein. Therefore, the present invention presents solutions to the problems encountered in the various water heaters described above, in addition to solving problems presented in other heaters that operate based on pressure differences.

BRIEF DESCRIPTION OF THE FIGURES

The characteristic details of the invention are described in the following paragraphs in conjunction with the accompanying figures, which are for the purpose of defining the invention but without limiting its scope.

Figure 1 illustrates an exterior view of a water heater according to the invention, where its external components are shown. Figure 2 illustrates an internal view of the water heater without an outer housing according to the invention.

Figure 3 illustrates an internal view of the water heater without outer casing and top cover, showing the location of a temperature sensor according to the invention.

Figure 4 illustrates an internal view of the water heater without external housing and heat collector, showing the location of a temperature sensor according to the invention.

Figure 5 illustrates a detail view of the location of a temperature sensor in the water heater according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

An external view of a water heater 10 according to the present invention is illustrated in Figure 1. The water heater 10 is formed by an outer housing 20, an upper cover 30, a lower cover 40, a cold water inlet tube 50, a hot water outlet tube 60, a chimney cup 70 and a regulating mechanism 80 .

The cold water inlet tube 50 is connected to a water container 65, which provides a hydrostatic pressure required for the operation of the water heater 10, where the hydrostatic pressure is generated by a water column Hl generated by the difference in heights of the water level of the water container 65 and the hot water outlet of an accessory or key 66 connected to the hot water outlet tube 60.

The water column Hl has a height greater than 8 cm, which generates the hydrostatic pressure required for the operation of the water heater 10.

The outer casing 20 is preferably made of metallic material and protects the internal elements of the water heater 10. The outer casing 20 has the upper cover 30 in its upper part and the lower cover 40 in its lower part forming a thermally insulating structure.

The chimney cup 70 has the function of retaining the combustion gases of the gas inside the water heater 10, to ensure greater heat exchange between the combustion gases and the cold water, in addition to preventing the entry of foreign objects into the water heater inside 10.

The temperature difference between the cold inlet water and the hot water outlet of the water heater 10 is in the range of 20 ° C to 37 ° C.

Figures 2, 3 and 4 illustrate the interior of the water heater 10 according to the present invention. The water heater 10 has a cold water inlet tube 50, a hot water outlet tube 60, a heat collector 100, a rolled tube 110, a heat exchanger 120, a temperature sensor 130, a regulating mechanism 80, a heat source 140 and an activator 150. The heat source 140 can be a gas burner or an electric resistor and is located on the lower cover 40 and concentrically inside the heat collector 100 which is made of metallic material.

In a preferred embodiment, the heat collector 100 has a hollow tronconic shape such that it has the largest diameter that is close to the heat source 140 and the bottom cover 40, while the smaller diameter is the one that It is close to the upper cover 30, and whose technical function is to absorb the maximum amount of heat generated by the heat source 140, because if it is a gas burner, the heat collector 100 acts as a combustion chamber 160 in a conical shape that is coupled to the natural shape of the flame that emerges from the gas burner, which tends to be larger in diameter at the base and smaller in diameter at the top. The heat collector 100 in turn also covers a large portion of the heat exchanger 120, this in order to concentrate the heat generated by the heat source 140 in the heat exchanger 120.

The wound tube 110 consists of a metal tube, generally of copper, or aluminum, through which the water to be heated circulates, and is wound in the same direction on and in contact with the external surface of the heat collector 100 and may be attached to said surface by welding. The wound tube 110 has a first end 111 and a second end 112, and at the first end 111 is attached to the cold water inlet tube 50.

The wound tube 110 being attached to the heat collector 100 facilitates the transfer of heat (from heat source 140) to the flow of water circulating therein. The exchange of heat from heat source 140 to the heat collector 100 is by radiation and which in turn transfers heat by conduction rolled tube 110 and this in turn transfers heat to the flow of water by conduction - convection.

The heat exchanger 120 consists of a spiral or broken line tube surrounded by heat diffusers and has an inlet 121 and an outlet 122 such that the inlet 121 is connected to the second end 112 of the wound tube 110 and the outlet 122 It is attached to the hot water outlet pipe 60.

The union of the cold water inlet tube 50, the hot water outlet tube 60, the wound tube 110 and the heat exchanger 120 define a water flow conduit.

The temperature sensor 130 is connected to the regulating mechanism 80 and is located in any part of the water flow duct defined by the union of the cold water inlet tube 50, the hot water outlet tube 60, the wound tube 110 and the heat exchanger 120. The temperature sensor 130 may be a gas bulb, a steam bulb, a bimetallic sensor, a nickel resistance probe, a palatal resistance probe, a chromel-constantan probe, a copper probe - constantan or a chromel-alumel probe. In the present embodiment, the temperature sensor 130 is located within the water flow conduit, however alternatively the temperature sensor 130 may be located anywhere outside the water flow conduit making contact directly with any external part. of the cold water inlet tube 50, the hot water outlet tube 60, the wound tube 110 and the heat exchanger 120 which together define a water flow conduit. Alternatively, surrounding the heat source 140 and on the lower cover 40, there is a cylindrical lower heat diffuser 170 which has the function of preventing the heating of the lower cover 40 and the outer casing 20 as it avoids the dissipation of the heat generated by the heat source 140 towards these elements, in such a way that it allows to reflect and concentrate the greatest amount of heat generated towards the heat collector 100.

In another alternative embodiment, the water heater 10 has an upper heat diffuser 180 between the upper cover 30 and the heat exchanger 120, in particular covering the upper part of the heat exchanger 120. The upper heat diffuser 180 has a hollow throne-conical shape in such a way that the smaller diameter is connected to an orifice for flue gas outlet 190 of the upper cover 30 where the chimney cup 70 is in turn. The upper heat diffuser 180 has the function of preventing the heating of the upper cover 30 and the outer casing 20 because it prevents the dissipation of the heat generated by the heat source 140 towards these elements, in such a way that it allows to reflect and concentrate the greater amount of heat generated towards the heat exchanger heat 120.

In an alternative embodiment where the energy source for the water heater 10 is the combustion of gas, the heat source 140 is a gas burner that is connected to a gas line for burner 141 which is close to a gas pilot 142 or an electronic device that generates an electric spark that acts as activator 150. In case the activator 150 is a gas pilot 142, this in turn is connected to a gas line for pilot 143 and a thermocouple 144. Both the burner gas line 141, pilot gas line 143 and thermocouple 144 are connected to regulator mechanism 80 which is a thermostat valve.

In another alternative embodiment where the power source for the water heater 10 is the electric power, the heat source 140 is an electric resistor that is connected to an electric power source and an electric switch that acts as activator 150. The electrical resistance is in turn connected to an electric power regulator that acts as the regulating mechanism 80.

A detail view of the location of the temperature sensor 130 in the water heater according to the invention, in particular located inside one of the tubes or turns of the heat exchanger 120. is illustrated in Figure 5. Heat exchanger 120 is constituted by a plurality of straight tubes 123 with a plurality of heat diffusers 125 on its surface and interconnected to a plurality of curved tubes 124 forming a coil. Heat exchanger 130 is connected to winding 110.

The temperature sensor 130 is connected to the regulating mechanism 80, in this case the thermostat valve, and is located within the water flow F. The temperature sensor 130 is completely surrounded by water outside and the installation of the thermostat valve is in such a way that the water that flows does not enter the inside of the thermostat valve because there is a physical barrier that prevents the entry of water to the thermostat valve.

In one embodiment of the invention, a local heating module 200 can be found next to the temperature sensor 130 which can be a electrical resistance or a gas pilot. In this embodiment, the local heating module 200 is located concentrically to the temperature sensor 130 when this temperature sensor 130 is located within the water flow conduit, in this case within a straight tube 123 of the heat exchanger 120, however, the heating module 200 may also be located close to the temperature sensor 130 when the temperature sensor 130 is located on an outside of the water flow conduit.

The local heating module 200 allows to maintain a generally constant temperature of the water that is stagnant in the portion of the water flow duct where the temperature sensor 130 is located in order to prevent the temperature sensor 130 from detecting a change of temperature that activates the regulating mechanism 80 that turns on the heat source 140 as long as there is no water circulation in the water heater 10, that is, as long as there is no output of the hot water from the water heater 10, the heating module 200 prevents the activation or ignition of the heat source 140 by the regulating mechanism 80 as long as there is no water circulation.

The operation of the instantaneous low-pressure water heater 10 of the present configuration is described below, jointly looking at Figures 1 to 5.

When the hot water tap is placed in the open position the water that is in the water container 65 (See Figure 1), exerts some pressure to flow the water through the internal elements of the water heater 10, which generates a flow of water F. The water flow F passes around the temperature sensor 90, where the combustion gases generated in the combustion chamber 160, transfers the heat to the water flow F.

The cold water is supplied by the water container 65 (see Figure 1) which enters the water heater 10 of the invention through the cold water inlet tube 50 which in turn is conducted to the wound tube 110 At this point, the water has an ambient temperature, which varies according to the different seasons of the year.

When the hot water tap (not shown) is closed, the cold water is static inside the internal elements, the cold water inlet tube 50, the hot water outlet tube 60, the coiled tube 110 and the exchanger of heat 120, hereinafter referred to as the water flow conduit of the water heater 10 of the invention. When this happens, the heat source 140, in this case the gas burner, is turned off and the activator 150, in this case the gas pilot, is on, which generates that the temperature in the combustion chamber 160 is find at a temperature higher than the ambient temperature, which we will call "temperature 1".

The heat (at a temperature 1) of the combustion chamber 160 is absorbed by the stagnant water inside the water heater elements 10, in this case, in particular in the heat exchanger 120 by radiation effect towards the plurality of diffusers of heat 125 and in turn by conduction effect transferred to the tubes straight 123. The heat absorbed by the straight pipes 123 is transferred to the water inside and in turn is perceived by the temperature sensor 130.

In another intention of the invention the temperature sensor 130 could be within the water flow somewhere in the wound tube 110, the heat exchanger 120, the cold water inlet tube 50 or the hot water outlet tube 60, where the heat (temperature 1) of the combustion chamber 160 is absorbed by the stagnant water inside the elements of the water heater 10, due to radiation effect to the heat collector 100 and in turn by conduction effect they transfer it to the rolled tube 110, maintaining the temperature 1 in the stagnant water thus preventing the gas burner from igniting (heat source 140).

Heat at temperature 1 is maintained in the combustion chamber 160 by the flame generated by the gas pilot 142, which prevents the temperature of the water contained in the elements of the water heater 10 from decreasing, whereby the water contained in the elements of the water heater 10 it maintains a temperature that allows the regulating mechanism 80 to be maintained, in this case the thermostat valve, in the closed position to prevent the flow of gas towards the heat source 140 which in this case is a burner gas.

When, due to the location of the temperature sensor 130, it is found that the heat generated by the gas pilot 142 does not heat enough to keep the water inside the water flow conduit at a generally constant temperature 1, then it is necessary use local heating module 200. The local heating module 200 in this configuration (operation of the gas water heater) is a gas pilot placed in a position close to the temperature sensor 130 and powered by an alternating gas pilot line (not shown), thus ensuring the temperature 1 in the water surrounding temperature sensor 130.

When the hot water tap (not shown) is opened, the water flow F begins its journey inside the water heater 10 of the invention by displacing the static water contained therein. The water flow F travels through the cold water inlet tube 50 and the wound tube 110 to the heat exchanger 120.

When the water initially contained in the elements of the water heater 10 (which was heated by the flue gases of the gas pilot 142 or of the local heating module 200) is displaced and replaced by water flow F of lower temperature, then this Temperature decrease is perceived by the temperature sensor 130 which activates the regulating mechanism 80, in this case the thermostat valve, to place it in the open position and lets the gas flow to the gas burner (heat source 140) through the burner gas line 141.

When the gas flow leaves the gas burner (heat source 140), the flame of the gas pilot 142 ignites it, thus causing combustion gases with sufficient heat inside the combustion chamber 160. This heat of the gasses combustion heats heat collector 100.

The heat collector 100 is heated by radiation due to the combustion gases generated inside the combustion chamber 160. The heat is then transmitted by conduction to the wound tube 110 and the heat exchanger 120 which in turn they transfer heat to the flow of water that circulates within these elements by conduction-convection.

The temperature inside the combustion chamber 160 is high, due to the combustion of the gases, which allows to increase the temperature of the water flow F greater than or equal to 25 ° C, in the time period required for a water flow F according to the heater capacity in liters per minute.

Within the heat exchanger 120 there is a greater heat exchange of the combustion gases of the combustion chamber 160 with the flow of water F circulating therein. The flow of heated water F is then conducted to the hot water outlet through the client water outlet tube 60 to finally exit through the hot water tap 66

The heat transmission in the heat exchanger 120 is greater because the combustion gases at that height are of a higher temperature, in addition to the tubes that make up the heat exchanger 120 having a plurality of heat diffusers 125 which consist of thin sheets positioned radially to the rector tubes 123 that comprise it, the plurality of thin sheets are located one after the other in the axial direction of the rector tubes 123 that make up the heat exchanger 120.

The heat transmission in the heat exchanger 120 is such that the heat generated by the combustion gases within the combustion chamber 160 is transferred by conduction to the plurality of heat diffusers 125 and transmitted by conduction to the straight tubes 123 that conform to heat exchanger 120. The Heat transfer of straight pipes 123 to the water flow F is by conduction-convection.

As long as the hot water tap 66 remains open, the water flow F will continue to circulate through the elements of the water heater 10 continuously displacing the water contained therein, so that the temperature sensor 130 will be perceiving a lower temperature with respect to the water temperature being displaced, which allows to keep the thermostat valve open (regulating mechanism 80) and therefore the gas supply to the gas burner (heat source 140).

Once the hot water tap 66 is closed, the water circulating within the elements of the water heater 10 of the invention stagnates therein, whereby the water contained statically in the elements of the water heater 10 It increases its temperature due to the heat of the combustion gases still generated by the gas burner (heat source 140) that remains on until the temperature sensor 130 perceives a water temperature statically contained in the elements of the water heater 10 causing the thermostat valve to close (regulating mechanism 80) and thus preventing the flow of gas to the gas burner (heat source 140), only the gas pilot 141 (the activator 150) remaining on.

EXAMPLE OF EMBODIMENT OF THE INVENTION

The following example is demonstrative and not limiting to the invention of the water heater 10 of the present invention. Table 1 shows a profile of temperatures detected on the surface of the water heater 10, in which the following has been used in its preparation:

• A copper pipe of 11.28 mm of internal diameter and 12.7 mm of external diameter in the wound tube 110, where the wound tube 110 is made up of a total of 4 whole turns.

• A copper pipe of 14.3 mm of internal diameter and 15.88 of external diameter for the pipe that integrates the heat exchanger 120, the heat exchanger 120 is made up of a total of nine straight pipes 123, each with a plurality of diffusers of heat 125. The configuration of heat exchanger 120 is such that five straight tubes 123 are in the lower part and four straight tubes 123 are in the upper part, interconnected by sections of curved tubes 124 in the form of "U" , with the same internal and external diameters as straight pipes 123.

• Heat collector 100 has a lower diameter of 21 cm and an upper diameter of 18 cm and a height of 30 cm.

Table 1 In the readings of the temperatures and pressures were taken by means of a thermometer and a manometer.

Based on the embodiments described above, it is contemplated that the modifications to these described embodiments, as well as the alternative embodiments will be considered apparent to a person skilled in the art under the present description. It is therefore contemplated that the claims encompass said alternative embodiments that are within the scope of the present invention or its equivalents.

Claims

1. A water heater comprising:

a cold water inlet tube;

a hot water outlet pipe;

a heat collector;

a tube wound in the same direction in said heat collector with a first end and a second end, and joined at its first end with the inlet tube

a heat exchanger with an inlet and outlet, and joined by its entrance to the second end of the wound tube and by its outlet to the hot water outlet tube; and wherein the inlet tube, outlet tube, coiled tube and heat exchanger define a water flow conduit;

a temperature sensor attached to a regulatory mechanism;

a heat source concentric to said heat collector; Y

an activator connected to said heat source and said temperature sensor;

characterized in that said temperature sensor is located anywhere in said water flow conduit.

2. The water heater of claim 1, characterized in that said heat collector is of a throne-conical shape.

3. The water heater of claim 1, characterized in that said heat collector covers said heat exchanger.

4. The water heater of claim 1, characterized in that said heat source is a gas burner or an electric heater.

5. The water heater of claim 1, characterized in that said activator is a gas pilot, an electrical switch or an electronic device that generates an electric spark.

6. The water heater of claim 1, characterized in that said temperature sensor is located within said water flow conduit.

7. The water heater of claim 1, characterized in that said temperature sensor is located on an outside of said water flow conduit.

8. The water heater of claim 1, characterized in that said temperature sensor is a gas bulb, a steam bulb, a bimetallic sensor, a nickel resistance probe, a palatal resistance probe, a chromel probe - constantan, a copper-constantan probe or a chromel-alumel probe.

9. The water heater of claim 1, characterized in that said regulating mechanism is a thermostat valve or an electric power regulator.

10. The water heater of claim 1, characterized in that it also includes a local heating module close to said temperature sensor.

11. The water heater of claim 10, characterized in that said local heating module is an electrical resistor or a gas pilot.

12. The water heater of claim 10, characterized in that said heating module is located close to said temperature sensor when said temperature sensor is located on an outside of said water flow conduit.

13. The water heater of claim 10, characterized in that said heating module is located concentrically to said temperature sensor when said temperature sensor is located within said water flow conduit.

14. The water heater of claim 1, characterized in that it further includes a lower heat diffuser.

15. The water heater of claim 1, characterized in that it further includes a superior heat diffuser.