EP1184767B1

EP1184767B1 - Control method of thermostatic system

Info

Publication number: EP1184767B1
Application number: EP00118910A
Authority: EP
Inventors: Nan Fang Chang
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-08-31
Filing date: 2000-08-31
Publication date: 2003-12-17
Anticipated expiration: 2020-08-31
Also published as: EP1184767A1; DE60007309D1; ATE256884T1

Abstract

The present invention proposes a control method of a thermostatic system, especially a control method of a first and a second electromagnetic valves of a thermostatic system of a water heater. When gas outflow output to a main stove is too large, the first electromagnetic valve is controlled to be open and the second electromagnetic valve is controlled to be close. Gas will be transferred via the first gas room to the second gas room. The control of gas charge of the second gas room is thus performed so as to decrease the open degree of the first gas outlet used to output gas to the main stove, hence decreasing gas outflow. When gas outflow output to the main stove is too small, the first electromagnetic valve is controlled to be close and the second electromagnetic valve is controlled to be open. Therefore, gas can not be transferred to the second gas room, and gas in the second gas room can be output via the second gas outlet used to output gas to a pilot flame. The control of gas discharge of the second gas room is thus performed so as to increase the open degree of the first gas outlet, hence increasing gas outflow. The control of gas charge and discharge of the second gas room is performed by controlling the two electromagnetic valves so as to exactly control gas outflow of the first gas outlet. Thermostatic control of the water heater can thus be achieved. <IMAGE>

Description

Field of the invention

The present invention relates to a control method of a thermostatic system and, more particularly, to a control method applicable to a water heater according to the pre-characterizing part of claim 1, wherein two electromagnetic valves are exploited to exactly control gas outflow at the gas outlet. Thereby, thermostatic control of the water heater can be achieved.

Background of the invention

As shown in Fig. 1, a gas switch control system 10 is installed in a prior art water heater. The gas switch control system 10 comprises a gas inlet 11 for inputting gas, a first gas outlet 12 for outputting gas to a main stove, and a second gas outlet 13 for outputting gas to a pilot flame. A valve 14 is arranged between the gas inlet 11 and the first gas outlet 12 and the second gas outlet 13. The action of the valve 14 is controlled by a water pan 15. When cold water is input from a cold water inlet 16 into the water pan 15, the valve 14 will be pushed open so that gas can be transferred from the gas inlet 11 to the first gas outlet 12 and the second gas outlet 13.
A switch middle seat 17 is installed between the first gas outlet 12 and the second gas outlet 13. The switch middle seat 17 comprises an upper lid 18 and a bottom seat 19, which are assembled to form a hollow shell. A valve sheet 20 made of resilient material such as rubber is installed in the switch middle seat 17. The valve sheet 20 is fixedly gripped between the upper lid 18 and the bottom seat 19. The valve sheet 20 is connected to a connecting link 21. One end of the connecting link 21 has a valve 22. The valve 22 can be used to control the open or close of the first gas outlet 12.
The valve sheet 20 partitions the switch middle seat 17 into a first gas room 23 and a second gas room 24. A first electromagnetic valve 25 and a second electromagnetic valve 26 are installed on the side wall of the second gas room 24. The first electromagnetic valve 25 is normally open and situated between the first gas room 23 and the second gas room 24. The first electromagnetic valve 25 can be used to control the open or close state between the first gas room 23 and the second gas room 24. The second electromagnetic valve 26 is normally close and situated between the second gas room 24 and the second gas outlet 13. The second electromagnetic valve 26 can be used to control the open or close state between the second gas room 24 and the second gas outlet 13, i.e., the open or close of the second gas outlet 13.
When cold water is input from the cold water inlet 16 into the water pan 15, the valve 14 will be pushed open through the water pan 15. Therefore, gas can be transferred from the gas inlet 11 into the first gas room 23 of the switch middle seat 17. Gas can also be transferred via the first electromagnetic valve 25 at open state to the second gas room 24. At this time, the second electromagnetic valve 26 can be controlled to be open so that gas can be transferred to the pilot flame via the second gas outlet 13, hence facilitating action of ignition. When the pilot flame has been ignited, the first electromagnetic valve 25 can be controlled to be close so that gas in the second gas room 24 will be gradually burned out. At this time, the gas pressure in the first gas room 23 will be larger than that in the second gas room 24. Therefore, gas will push the valve sheet 20 to move toward the direction of the second gas room. The valve 22 will be jointly moved toward the direction of the switch middle base 17 through the connecting link 21. The first gas outlet 12 can thus be controlled to be open so that gas can be output via the first gas outlet 12 to the main stove.
However, in the above gas switch control system 10 of prior art, the first electromagnetic valve 25 and the second electromagnetic valve 26 can only make a simple on or off action. Gas outflow of the first gas outlet 12 output to the main stove can not be exactly controlled so that thermostatic control of the water heater can not be achieved.
In addition, there is one relative prior art DE 29904815U1 containing the similar structure than the Fig. 1 at the portion of gas chamber and the electromagnetic valve.

Summary and objects of the present invention

The primary object of the present invention is to provide a control method of a thermostatic system, wherein two electromagnetic valves of a thermostatic system of a water heater can be controlled to perform the control of gas charge and discharge of a second gas room so as to push a valve sheet forwards or backwards. Thereby, gas outflow of a first gas outlet output to a main stove can be exactly controlled so that linearity of temperature change of the water heater is more apparent. Thermostatic control of the water heater can thus be achieved.
To achieve the above object, the present invention provides a control method of a thermostatic system according to independent claim 1. When gas outflow output to a main stove is too large, the first electromagnetic valve is controlled to be open and the second electromagnetic valve is controlled to be close. Gas will be transferred from the first gas room to the second gas room. The control of gas charge of the second gas room is thus performed so as to decrease the open degree of the first gas outlet used to output gas to the main stove, hence decreasing gas outflow. When gas outflow output to the main stove is too small, the first electromagnetic valve is controlled to be close and the second electromagnetic valve is controlled to be open. Gas can not be transferred to the second gas room, and gas in the second gas room can be output via the second gas outlet used to output gas to a pilot flame. The control of gas discharge of the second gas room is thus performed so as to increase the open degree of the first gas outlet, hence increasing gas outflow.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawings, in which:

Brief description of drawing:

Fig. 1 is a cross-sectional view of a gas switch control system in prior art;
Fig. 2 is a cross-sectional view of the present invention when not used;
Fig. 3 is a cross-sectional view of the present invention when being ignited;
Fig. 4 is a cross-sectional view of the present invention after ignited;
Fig. 5 is a block diagram of the control method of the present invention;
Fig. 6 is a timing diagram of the control method of the present invention.

Detailed description of preferred embodiment

The present invention relates to a control method of a thermostatic system as shown in Fig. 2. The present invention is applicable to a thermostatic system 50 of a general water heater. The thermostatic system 50 is roughly like a gas switch control system of prior art. The thermostatic system 50 comprises a gas inlet 51 for inputting gas, a first gas outlet 52 for outputting gas to a main stove, and a second gas outlet 53 for outputting gas to a pilot flame. A valve 54 is arranged between the gas inlet 51 and the first gas outlet 52 and the second gas outlet 53. The action of the valve 54 is controlled by a thimble 551 of a water pan 55. The water pan 55 has a cold water inlet 56. When cold water is input from the cold water inlet 56 into the water pan 55, the thimble 551 will be jointly moved so that the valve 54 will be pushed open to let gas be transferred from the gas inlet 51 to the first gas outlet 52 and the second gas outlet 53.
A switch middle seat 57 is installed between the first gas outlet 52 and the second gas outlet 53. The switch middle seat 57 comprises an upper lid 58 and a bottom seat 59, which are assembled to form a hollow shell. A valve sheet 60 made of resilient material such as rubber is installed in the switch middle seat 57. The valve sheet 60 is fixedly gripped between the upper lid 58 and the bottom seat 59. The valve sheet 60 is connected to a connecting link 61. One end of the connecting link 61 has a valve 62. The valve 62 can be used to control the open or close and the gas flux of the first gas outlet 52.
The valve sheet 60 partitions the switch middle seat 57 into a first gas room 63 and a second gas room 64. A first electromagnetic valve 65 and a second electromagnetic valve 66 are installed on the side wall of the second gas room 64. The first electromagnetic valve 65 is normally open and situated between the first gas room 63 and the second gas room 64. The first electromagnetic valve 65 can be used to control the open or close state between the first gas room 63 and the second gas room 64. The second electromagnetic valve 66 is normally close and situated between the second gas room 64 and the second gas outlet 53. The second electromagnetic valve 66 can be used to control the open or close state between the second gas room 64 and the second gas outlet 53, i.e., the open or close of the second gas outlet 53.
As shown in Fig. 3, when cold water is input from the cold water inlet 56 into the water pan 55, the valve 54 will be pushed open through the thimble 551 of the water pan 55. Therefore, gas can be transferred from the gas inlet 51 into the first gas room 63 of the switch middle seat 57. Gas can also be transferred via the first electromagnetic valve 65 at open state to the second gas room 64. At this time, the second electromagnetic valve 26 can be controlled to be open so that gas can be transferred to the pilot flame via the second gas outlet 53, hence facilitating action of ignition.
As shown in Fig. 4, when the pilot flame has been ignited, the first electromagnetic valve 65 can be controlled to be close so that gas in the second gas room 64 will be gradually burned out. At this time, the gas pressure in the first gas room 63 will be larger than that in the second gas room 64. Therefore, gas will push the valve sheet 60 to move toward the direction of the second gas room 64. The valve 62 will be jointly moved toward the direction of the switch middle base 57 through the connecting link 61. The first gas outlet 52 can thus be controlled to be open so that gas can be output via the first gas outlet 52 to the main stove.
The first electromagnetic valve 65 and the second electromagnetic valve 66 can be properly controlled in the present invention so that they can not only make a simple on or off action. As shown in Figs. 5 and 6, when a water temperature sensor detects the temperature is too high or gas outflow output to a main stove is too large, the first electromagnetic valve 65 is controlled to be open and the second electromagnetic valve is controlled to be close. Gas can transferred via the first gas room 63 to the second gas room 64. The control of gas charge of the second gas room 65 is thus performed to increase the gas pressure in the second gas room 64 so that the valve sheet 60 will be pushed to move toward the direction of the first gas room 63. The valve 62 will be jointly moved toward the direction of the first gas outlet 52 through the connecting link 61 to decrease the open degree of the first gas outlet 52, hence decreasing gas outflow output to the main stove. When the water temperature sensor detects the temperature is too low (insufficient) or gas outflow output to the main stove is too small, the first electromagnetic valve 65 is controlled to be close and the second electromagnetic valve 66 is controlled to be open. Therefore, gas can not be transferred to the second gas room 64, and gas in the second gas room 64 can be output via the second gas outlet 53. The control of gas discharge of the second gas room 64 is thus performed to let the gas pressure in the second gas room 64 decrease so that the gas pressure in the first gas room 63 will be larger than that in the second gas room 64. The valve sheet 60 will be pushed to move toward the direction of the second gas room 64. The valve 62 will be jointly moved toward the opposite direction of the first gas outlet 52 through the connecting link 61 to increase the open degree of the first gas outlet52, hence increasing gas outflow output to the main stove. When water is kept at a proper temperature, the first electromagnetic valve 65 and second electromagnetic valve 66 are controlled to be close.
To sum up, the control of gas charge and discharge of the second gas room 64 can be performed by controlling the two electromagnetic valves 65 and 66. The valve sheet 66 can be pushed to move forwards or backwards so that gas outflow of the first gas outlet 52 output to the main stove can be exactly controlled. Thermostatic control of the water heater can thus be achieved.

Claims

A control method of a thermostatic system, especially a control method of a first electromagnetic valve and a second electromagnetic valve of a thermostatic system of a water heater, said control method characterized in that:

controlling said first electromagnetic valve to be open in a first time interval and said second electromagnetic valve to be kept in close so that gas can be transferred via a first gas room to a second gas room for performing the control of gas charge of said second gas room and thus the open degree of a first gas outlet used to output gas to a main stove can be decreased when gas outflow transferred to the main stove is too large;

controlling said first electromagnetic valve to be kept in close and said second electromagnetic valve to be open in a second time interval so that gas can not be transferred to said second gas room and gas in said second gas room can be transferred via a second gas outlet used to exhaust gas to a pilot flame for performing the control of gas discharge of said second gas room . and thus the open degree of said first gas outlet can be increased when gas outflow transferred to the main stove is too small;

after the said open action of the said first electromagnetic valve or the said second electromagnetic valve at a third time interval, checking the water temgerature then modulate the gas flow transferred to the main stove to a proper flow rate by controlling said first and second electromagnetic valves and controlling said first and second electromagnetic valves to be close when water is kept at a proper temperature;

whereby the control of gas charge and discharge of said second gas room can be performed by controlling said two electromagnetic valves so as to exactly control gas outflow of said first gas outlet.