SAFETY SYSTEM FOR A GAS APPARATUS FOR HEATING WATER

Abstract

A safety system for a gas apparatus (100) for heating water, the gas apparatus comprising a tank (1) for containing water and a first gas burner (2) for heating the water contained inside the tank (1). The safety system (200, 200′) comprises a first sensor (9) suitable for generating a first signal which represents a temperature of the water contained in the tank (1), a second sensor (10) suitable for generating a second signal which represents a temperature of the water contained in the tank (1), a supply circuit (11) for energizing a first actuator (4) of a first valve (3) which is arranged to allow to pass/intercept a flow of gas towards the first gas burner (2), the first actuator (4) being arranged to actuate so as to open and close the first valve (3) when it is energized and non-energized, respectively, a switch device (13) which is arranged in the supply circuit (11) in order to close/open the supply circuit (11) so as to energize/not to energize the first actuator (4), a digital processing unit (14) which is operatively connected to the first and/or second sensor (9, 10) and which is configured to compare a set-point value which represents a preselected temperature with the first or second signal and a control device (16) which is operatively connected to the switch device (13) and to the first and second sensors (9, 10). The control device (16) comprises an analogue comparator (17) which is operatively connected to the first and second sensors (9, 10) in order to compare the first signal with the second signal and the control device (16) is configured to generate a control signal (18) for controlling so as to open/close the switch device (13) on the basis of the comparison between the first and second signals carried out by the analogue comparator (17).

Claims

1. A safety system for a gas apparatus (100) for heating water, the gas apparatus comprising a tank (1) for containing water and a first gas burner (2) for heating the water contained inside the tank (1), the safety system (200, 200′) comprising: a first sensor (9) suitable for generating a first signal which represents a temperature of the water contained in the tank (1), a second sensor (10) suitable for generating a second signal which represents a temperature of the water contained in the tank (1), a supply circuit (11) for energizing a first actuator (4) of a first valve (3) which is arranged to allow to pass/intercept a flow of gas towards the first gas burner (2), the first actuator (4) being arranged to actuate so as to open and close the first valve (3) when the first actuator is energized and non-energized, respectively, a switch device (13) which is arranged in the supply circuit (11) in order to close/open the supply circuit (11) so as to energize/not to energize the first actuator (4), a digital processing unit (14) which is operatively connected to the first and/or second sensor (9, 10) and which is configured to compare a set-point value which represents a preselected temperature with the first or second signal and a control device (16) which is operatively connected to the switch device (13) and to the first and second sensors (9, 10), the control device (16) comprises an analogue comparator (17) which is operatively connected to the first and second sensors (9, 10) in order to compare the first signal with the second signal and the control device (16) is configured to generate a control signal (18) for controlling so as to open/close the switch device (13) on the basis of the comparison between the first and second signals carried out by the analogue comparator (17).

2. The safety system according to claim 1, wherein the analogue comparator (17) is operatively connected to the switch device (13) and is capable of generating the control signal (18) for controlling so as to open/close the switch device (13) on the basis of the comparison between the first and second signals.

3. The safety system according to claim 2, wherein the analogue comparator (17) is capable of generating the control signal (18) for controlling so as to open the switch device (13) if a difference between the first signal and the second signal is greater than a predefined value and for controlling so as to close the switch device (13) if the difference between the first signal and the second signal is less than or equal to the predefined value.

4. The safety system according to claim 1, wherein the control device (16) comprises the digital processing unit (14), the analogue comparator (17) being operatively connected to the digital processing unit (14) and being capable of generating an output signal (19) on the basis of a comparison between the first and second signals, the digital processing unit (14) being operatively connected to the switch device (13) and being capable of generating the control signal (18) for controlling so as to close the switch device (13) when the output signal (19) takes on a first value and for controlling so as to open the switch device (13) when the output signal (19) takes on a second value.

5. The safety system according to claim 4, wherein the analogue comparator (17) is capable of generating the second value of the output signal (19) if a difference between the first signal and the second signal is greater than a predefined value.

6. The safety system according to claim 1, wherein the first and second signals are analogue electrical signals.

7. A gas apparatus for heating water, the gas apparatus (100) comprising a tank (1) for containing water, a first gas burner (2) for heating the water contained inside the tank (1), a first valve (3) which is provided to allow to pass/intercept a flow of gas towards the first gas burner (2), a first actuator (4) which is provided to actuate so as to open and close the first valve (3) when it is energized and non-energized, respectively, and a safety system (200, 200′) according to claim 1.

8. The gas apparatus according to claim 7, wherein the gas apparatus (100) further comprises a thermoelectric generator (12) for energizing the supply circuit (11) and/or the digital processing unit (14).

9. The gas apparatus according to claim 8, wherein the gas apparatus (100) comprises a second gas burner (6), a second valve (7) which is provided to allow to pass/intercept a flow of gas towards the second gas burner (6), and towards the first gas burner (2), and a second actuator (8) which is connected to the supply circuit (11) and which is provided to actuate so as to open and close the second valve (7) when the second actuator is energized and non-energized, respectively, the first gas burner (2) being a main burner and the second gas burner (6) being a pilot burner which is configured to light the main burner by means of a relevant pilot flame.

10. The gas apparatus according to claim 9, wherein the thermoelectric generator (12) is associated with the second burner (6) so as to be energized by the flame generated by the second burner (6).

11. A method for controlling a gas apparatus (100) according to claim 7, the method comprising: generating a first signal which represents a temperature of the water contained in the tank (1) of the gas apparatus (100) by means of the first sensor (9) of the gas apparatus (100), generating a second signal which represents a temperature of the water contained in the tank (1) of the gas apparatus (100) by means of the second sensor (10) of the gas apparatus (100), comparing the first signal with the second signal by means of the analogue comparator (17) of the gas apparatus (100), generating a control signal (18) by means of the control device (16) of the gas apparatus (100) on the basis of the comparison between the first and second signals and controlling so as to close/open the switch device (13) of the gas apparatus (100) by means of the control signal (18) so as to energize/not to energize the first actuator (4) of the gas apparatus (100).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Features and advantages of the invention will be better appreciated from the following detailed description of preferred embodiments thereof which are illustrated by way of non-limiting example with reference to the appended Figures, in which:

[0065] FIG. 1 is a schematic view of a gas apparatus according to the invention,

[0066] FIG. 2 is a schematic view of a first embodiment of a safety system according to the invention,

[0067] FIG. 3 is a schematic view of a second embodiment of a safety system according to the invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0068] With reference initially to FIG. 1, there is generally designated 100 a gas apparatus for heating water which is constructed according to the present invention.

[0069] The gas apparatus 100 comprising a tank 1 for containing water, a first gas burner 2 for heating the water which is contained inside the tank 1, a first valve 3 which is provided to allow to pass/intercept a flow of gas towards the first gas burner 2, a first actuator 4 arranged to actuate so as to open and close the first valve 3 when it is energized and non-energized, respectively, and a safety system according to the invention.

[0070] The gas apparatus 100 further comprises a second gas burner 6, a second valve 7 which is provided to allow to pass/intercept a flow of gas towards the first and second gas burners 2, 6 and a second actuator 8 arranged to actuate so as to open and close the second valve 7 when it is energized and non-energized, respectively.

[0071] The first valve 3 and the first gas burner 2 represent a main valve and a main burner of the gas apparatus 100, respectively, while the second valve 7 and the second gas burner 6 represent a pilot valve and a pilot burner of the gas apparatus 100, respectively.

[0072] FIG. 2 shows a first embodiment of the safety system according to the invention which is generally designated 200.

[0073] The safety system 200 comprises a first and a second sensor 9, 10 which are capable of generating a first and a second signal which represent a temperature of the water contained in the tank 1, respectively. In particular, the first and second sensors 9, 10 are temperature sensors which are configured to generate a respective analogue signal in terms of voltage.

[0074] The safety system 200 further comprises a supply circuit 11 for energizing the first actuator and the second actuator 4, 8. The first actuator and the second actuator 4, 8 are therefore connected to the supply circuit 11 via which they are energized by a thermoelectric generator 12, in particular a thermopile. The thermoelectric generator 12 is associated with the second gas burner 6 so as to be energized by the flame which is generated by this gas burner.

[0075] The safety system 200 comprises a switch device 13 which is arranged in the supply circuit 11 to close/open the supply circuit 11 so as to energize/not energize the first and the second actuators 4, 8.

[0076] The safety system 200 further comprises a digital processing unit 14 which is operatively connected to the first sensor 9 and which is configured to compare a set-point value which represents a preselected temperature with the first signal.

[0077] In particular, the digital processing unit 14 is a microcontroller which is supplied by the thermoelectric generator 12 via a relevant electrical circuit 21 which may comprise a DC/DC converter.

[0078] The digital processing unit 14 is operatively connected to the supply circuit 11 by means of a second switch device 5 in order to actuate the first and the second actuators 4, 8 on the basis of a comparison between the set-point value and the first signal, preferably on the basis of a difference between the signals mentioned above.

[0079] The set-point value may be selected manually by a user by means of a knob 15 or other known input device.

[0080] In addition, the safety system 200 comprises a control device 16 which is operatively connected to the switch device 13 and the first and second is sensors 9, 10.

[0081] The control device 16 may comprise the digital processing unit 14. The control device 16 comprises an analogue comparator 17 which is operatively connected to the first and second sensors 9, 10 in order to compare the first signal with the second signal.

[0082] The control device is further configured to generate a control signal 18 for controlling so as to open/close the switch device 13 on the basis of the comparison between the first signal and the second signal carried out by the analogue comparator 17.

[0083] In particular, the analogue comparator 17 is operatively connected to the switch device 13 and is capable of generating the control signal 18 for controlling so as to open/close the switch device 13 on the basis of the comparison between the first signal and the second signal.

[0084] Specifically, the analogue comparator 17 is capable of generating the control signal 18 for controlling so as to open the switch device 13 if the difference between the first signal and the second signal is greater than a predefined value and for controlling so as to close the switch device 13 if the difference between the first signal and the second signal is less than or equal to this predefined value.

[0085] Preferably, the predefined value is equal to 0.2 mV or 0.5 mV. FIG. 3 shows a second embodiment of the safety system according to the invention which is generally designated 200′.

[0086] The features of the safety system 200′ in common with those of the safety system 200 shown in FIG. 2 are indicated with the same reference numeral.

[0087] With reference to FIG. 3, the analogue comparator 17 is operatively connected to the digital processing unit 14 and is capable of generating an output signal 19 on the basis of the comparison between the first signal and the second signal.

[0088] The control device 16 comprises the digital processing unit 14, which is operatively connected to the switch device 13. In addition, the digital processing unit 14 is capable of generating the control signal 18 for controlling so as to close the switch device 13 when the output signal 19 takes on a first value and for controlling so as to open the switch device 13 when the output signal 19 takes on a second value.

[0089] In particular, the analogue comparator 17 is capable of generating the second value of the output signal 19 if the difference between the first signal and the second signal is greater than a predefined value while the first value of the output signal 19 is generated by the analogue comparator 17 if the difference between the first signal and the second signal is less than or equal to this predefined value.

[0090] Preferably, the predefined value is equal to 0.2 mV or 0.5 mV.

[0091] The safety system 200′ further comprises a signalling device 20 which is operatively connected to the digital processing unit 14 and which is provided to generate an audible and/or illuminated warning signal on the basis of the value taken on by the output signal 19 which is generated by the analogue comparator 17. Specifically, the signalling device 20 comprises a buzzer and a plurality of LED devices and does not emit any audible/illuminated signal if the output signal 19 takes on the first value, and emits an audible signal and/or illuminated signal if the output signal 19 takes on the second value.

[0092] The invention thereby achieves the objects set out, affording the advantages mentioned above with respect to the known solutions.