WO2013069823A2

WO2013069823A2 - Active power automatic control system of electric boiler and operation method thereof

Info

Publication number: WO2013069823A2
Application number: PCT/KP2012/000028
Authority: WO
Inventors: Munchol Bong; Hakmun BONG
Original assignee: Munchol Bong; Bong Hakmun
Priority date: 2011-11-07
Filing date: 2012-06-07
Publication date: 2013-05-16
Also published as: WO2013069823A3

Abstract

The present invention provides an active power automatic control system of an electric boiler capable of automatically and actively regulating an electric current applying to electrodes by control of feed water in quantity to the electric boiler according to a capacity of any steam consumption unit, and an operation method thereof. The active power automatic control system includes an electrode (100) comprising several planar plates (101) bundled up each other at equal distance by insulating rings (102) and a fastening rod (103) inserted through the insulating rings (102), terminals (104) and lead wires (105); a power regulating device (200) comprising an absorber (201), a buffer water tank (202), motor valves (203, 204, 205), check valves (207, 208), a water pump (206), a temperature sensor (221), a pressure sensor (222), a volt-ampere sensor and a controller (210); and a safety device (300) comprising a safety valve (301) and an explosive valve (302).

Description

ACTIVE POWER AUTOMATIC CONTROL SYSTEM OF

ELECTRIC BOILER AND OPERATION METHOD THEREOF

Technical field

The present invention relates to an electric boiler, more particularly, to an active power automatic control system of an electric boiler capable of automatically and actively regulating an electric current applying to electrodes by control of feed water in quantity to the electric boiler according to a capacity of any steam consumption unit, thereby providing a high energy efficiency and ensuring a safety of the electric boiler, and an operation method thereof.

Background art

In the conventional electric boilers for producing steam and hot water, for prevent an excessive temperature or pressure or current occurred within the electric boiler, they used the on-off mode of supply of power to automatically shut off supply of power or cut off current applying to electrodes or heating devices.

In the recently exploiting and used electric boilers, disclosed are methods for increasing electric power applying to the boiler step by step for the purpose to overcome the starting resistance, but they all limit to step controls of the electric power.

Such electric boilers have some drawbacks in that they can not increase or decrease output of steam freely according to various production capacities of steam consumption units, thereby causing waste of electric power due to a constant steam production or deteriorating quality of the products and production capacity, and in that manufacturing costs are expensive due to needs of many electric and electronic devices for control of operation of the electric boiler.

An active power controlled electric boiler was disclosed in KP20101004496, wherein the electric boiler includes a double space-structured steam generator, several motor valves for control of the operation of the boiler adapted for control of supply of water in quantity so as to regulate current flowing between electrodes, a water supply device capable of supplying water discontinuously. Drawbacks in this art are that the structure of it is some complicated and some technical solution cannot be easily applied to the conventional electric boilers, and that trouble of actuators such as motor valves often occurs, and that there is some fluctuation of electric power due to the discontinuous supply of water.

Objects of the Invention

In order to overcome the above mentioned drawbacks inherent in the prior arts, it is an object of the present invention to provide an active power automatic control system of an electric boiler capable of continuously regulating electric current applying to electrodes, by control of feed water in quantity to the electric boiler and providing a continuous water supply to a boiler water tank, so that the output of steam is automatically regulated actively and optimally according to the production loads of steam consumption units.

And it is another object of the present invention to provide an active power automatic control system that can be easily applicable in the conventional electric boilers.

Simple details of the invention

The above mentioned objects of the present invention are accomplished by providing an active power automatic control system which includes an electrode with a new structure, a simple power regulating device and a safety device, and an operation method thereof.

The electrode according to the present invention comprises several planar plates, terminals, lead wires, insulating rings and a fastening rod for the plates. Each of the plates is partitioned into a working region and an insulated region. The working region has an area enough to provide the maximum electric power of the electric boiler, and is coated with graphite for fur being easily separated therefrom. The insulated region is positioned over the working region and provided with the terminals at the upper part thereof, to which terminals lead wire are connected. And another edge insulated regions are formed around edges of the working regions of the plates to prevent any abrasion due to any edge discharge. Such plates are so bundled up as to be separated each other at an equal distance, practically, as much as a side thickness of the insulating ring and in parallel with each other by means of the insulating rings and the fastening rod for plates, which is inserted through the insulating rings. The insulating ring is of such a structure that the thickness of it is minimized, preferable ranges from 15 to 25mm, and that a current leakage path length is maximized, preferably ranges from 50 to 100mm. And the insulated region of each of the plates has an enough area such that a current leakage path length of it is longer than one of the insulating ring, and thereby an overall current leakage path length of each of the plates is maximized. And the several plates are parallel connected by the lead wires to the three-phrase power source unit so that a total current supplied from the power source is divided and flows through the several plates, thereby not only to minimize an electric load applying to each of the plates, but also to maximize the area of working regions of plates contacting with water, thereby generating a large quantity of steam at a short time.

Such a special structure of the electrode is favorable and also safe for enabling an active regulation of the electric power of the electric boiler by control of feed water in quantity.

The power regulating device according to the present invention includes an absorber, a buffer water tank, motor valves, check valves, a water pump, a controller, a volt-ampere sensor, a temperature sensor and a pressure sensor.

As the absorber, a well known injector is used, which has function of discontinuously sucking water up by the aid of steam and supplying to the buffer water tank. Or any alternative devices other than the injector are applicable. For example, any device capable of discontinuously sucking water up with the aid of vacuum due to steam condensation or hydrodynamic vacuum can be used.

The buffer water tank is for continuously supplying water supplied from the absorber to the boiler water tank under the condition of an equal pressure. Throughout this specification and claims, the terms "absorber" and "buffer water tank" are used only for the purpose of respectively indicating a device capable of sucking water up discontinuously and a device capable of storing water temporarily and continuously supplying the water to the boiler water tank.

The motor valves are coupled with the controller for control of degree of openness of it to regulate or cut off the supply of steam and water, or provide an equal pressure between the boiler water tank, the absorber and the buffer water tank.

The water pump is coupled with the controller for control of operation of it to pump up water from the source of water into the absorber or even in case of no working of the absorber, to provide the discontinuous supply of water from the source of water to the buffer water tank.

The controller includes several one-chip microprocessors so as to be programmed to control the motor valves and a water pump by use of the sensed temperature, pressure and current from the sensors according to a principle of "constant power first and constant temperature (or pressure) afterwards", thereby keeping electric power, temperature, pressure and current at the preset values, so that it ensures an optimal steam production and a safety of the electric boiler.

The above mentioned principle of "constant power first and constant temperature(or pressure) afterwards" should be understood that first of all, the controller is programmed to control all the motor valves and the water pump so as to increase electric power as long as reaches a preset electric power value, and then when it exceeds a preset electric power, to decrease or increase electric power in order to keep temperature and pressure within the boiler water tank at the preset temperature and pressure values.

The safety device comprises a safety valve and an explosion valve which are adapted to be splitted or exposed when the pressure within the boiler water tank continuously increases to the extent of danger by any reason of failure of the operation of the motor valves or the controller.

Advantageous effects

The present invention has an effect that it can regulate a current flowing through the electrode(s) freely and supply water to the electric boiler continuously, thereby optimizing an output of steam and also minimizing the electric power consumption.

Further, the present invention has an effect that since it supplies electricity to the electric boiler in advance of supplying of water to the boiler water tank other than be done in the conventional boilers, it can easily generate steam in a short time, and that when the supply of power is on or off, no electric spark occurs in the switching circuits, and that any current discharge through fur of the electrode hardly occurs.

Further, the present invention has an effect that it ensures a stable steam generation irrespective of variation or fluctuation of electric voltage and frequency of power source, and that even if under an abnormal working condition such as power stoppage, overvoltage and overpressure and so on, it ensures a safety of operation of the electric boiler.

Further, the present invention has an effect that it can be easily applicable in the conventional electric boilers, and that since the total volume of the electric boiler of the present invention is approximately one fifth of that of the conventional boiler for the same capacity, it can be installed by the side of a steam consumption unit, thereby reducing a loss of heat within the pipe lines and also by reason of pressurization needed for transmission of produced steam to the consumption units.

Further, the present invention has an effect that there is no power fluctuation because of continuously supplying of water to the boiler water tank.

Having the above mentioned effects, it reduces power consumption by 30 to 50% during whole operation of the electric boiler as compared with that in the conventional electric boilers for the same capacity. Brief description of Drawings

The above mentioned objects, features and advantages of the present invention will be more clearly understood in the following detailed description in conjunction with accompanying drawings, in which:

Figure 1 is a structure view of an active power automatic control system of an electric boiler according to an exemplary embodiment of the present invention.

Figure 2 is for viewing a structure of an electrode, parallel connection of lead wires and a side section of an insulating ring, according to the embodiment of the present invention.

Figure 3 shows an alternative device which can be applied in place of an injector used as an absorber in a power regulating device, according to the embodiment of the present invention.

Figure 4 shows another alternative device of the injector of the power regulating device. Figure 5 is for showing an operating mode of the power regulating device at the start-up of the electric boiler.

Figure 6 is for showing of supplying water to a boiler water tank by means of the power regulating device during the normal operation of the electric boiler.

Figure 7 is for showing of decreasing electric power by means of the power regulating device during operation of the electric boiler, or for showing that the state of the electric boiler returns to the initial condition of operation when it stopped an operation of the electric boiler.

Figure 8 is for showing that when the active power automatic control system fails to work, a safety device acts to discharge water of the boiler water tank through a safety valve (or an explosive valve), and thereby the electric boiler returns to the initial condition of operation.

Figure 9 is a flow chart for showing a control principle of a controller.

Best mode for carrying out the above invention

Hereinafter, an active power automatic control system according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, it will be understood that like reference numbers refer to like elements throughout the drawings. Additionally, in the description, well known functions and structures will not be explained herein not to obscure the invention.

As shown in Fig. 1, an active power automatic control system according to an exemplary embodiment of the present invention includes an electrode 100, a power regulating device

200 and a safety device 300.

The electrode 100 as shown in Fig. 2 is structured in such a manner that plates 101 are bundled up at an equal distance, which distance is as long as a side thickness of an insulated ring 102, by means of a fastening rod 103 inserted through openings of insulating rings 102.

Each of the plates 101 is partitioned into a working region 107 and an insulated region 108.

And another edge insulated regions 106 are formed around edges of the working regions 107 of the plates 101. The working regions 107 have an enough area to generate the maximum steam output of an electric boiler according to the embodiment and are coated with graphite for protecting the metal layers thereof and for fur being easily separated therefrom. Along with this, they are further processed by the help of physico-chemical methods with a corrosion inhibitor and an adhesion reinforcing agent for metal surface and so on. The insulated regions 108 are filmed with insulating materials, and one ends of the lead wires 105 are connected to the terminals 104 positioned at upper parts of the insulated regions 108 and another ends connected to the three-phase power supply unit 400 of the electric boiler.

The insulating rings 102 are so structured as to minimize a distance "a" between the plates

101 and also to maximize a current leakage path length "L" thereof.

Since the electrode 100 is working at a boundary surface between water and steam, fur (metal ions) dissolved in water passes beyond a boiling layer region and adheres to the insulating rings. Having such a configuration of the electrode 100, it can generate steam in a short time (within about tens of seconds), and also there occurs no spark discharge by fur. And because the several plates are parallel connected by the lead wires 105 to the three-phase power supply unit 400, a total area of the plates contacting with water are maximized, thereby generating a large quantity of steam in a short time (see Fig. 2).

A power regulating device shown in Fig. 1 comprises an absorber 201, a buffer water tank 202, motor valves (203, 204, 205), a water pump 206, check valves (207, 208), a controller 210, a volt-ampere sensor (not shown in Figs.), a temperature sensor 221 and a pressure sensor 222.

As the absorber 201, an injector is used, and the water pump 206 is adapted to pump up water into the absorber 201 and also to supply water to the buffer water tank 202 discontinuously without working of the injector.

The motor valve 203 is adapted to supply or cut off some of the generated steam into the absorber 201, and the motor valve 204 to adjust a degree of the openness of it to regulate or cut off the supply of water in quantity from the buffer water tank 202 to the boiler water tank, and the motor valve 205 to discharge or close off water from the boiler water tank to the water source. And check valves (207, 208) are for leading water or steam in a single direction.

An alternative device of the absorber 201 shown in Fig. 3 is so structured that when opening or closing up the motor valves, the steam flowed into the absorber 201 is condensed, thereby sucking up water from the water source and then under equal pressure, supplying water to the buffer water tank 202.

In Fig. 4, another alternative device as the absorber is shown, wherein it is formed of two condensation tanks and the motor valve 203 is three-way valve. When the motor valve 203 is opened, steam flows down to a lower condensation tank and thereby water of the lower condensation tank flows to the buffer water tank 202. And when the motor valve 203 is closed, the steam filled in the lower condensation tank flows up again into the upper condensation tank and water of the upper condensation tank flows down to the lower condensation tank, the while it simultaneously sucks water up with the aid of vacuum formed by steam condensation and hydrodynamic vacuum.

A controller 210 shown in Fig. 1 is positioned on the upper surface of the electric boiler or can be positioned convenient for an user to operate it, and the volt-ampere sensor is installed at a terminal of a power supply unit of the electric boiler, and temperature and pressure sensors (221, 222) are installed in a main body of the electric boiler.

And as a safety device 300, a safety valve 301 and an explosive valve 302 as shown in Fig. 1 are so installed at the main body of the electric boiler as to be positioned lower than bottoms of the working regions of the plates 101, preferable about 10 mm lower.

Mode for the invention

An operation of the above mentioned active power automatic control system of the electric boiler will now be explained.

First of all, the user turns on the controller 210 and sets up a predetermined electric power, temperature, pressure and a threshold current by use of a plurality of buttons of the controller 210 with which the user can change the predetermined values at one's option. .

Then, it supplies electricity to the electric boiler, and it switches on the controller 210 to start operating, thereby closing up the motor valve 205 and opening the other motor valves (203, 204).

And the water pump 206 acts to pump up water from the water source into the absorber 201, and then water flows through the buffer water tank 202 into the boiler water tank, thereby generating steam (see Fig.5).

The current (or voltage) applying to the electrode 100 is detected by the volt-ampere sensor and inputted to the controller 210. If the power applying to the electrode comes next to the preset electric power (preferable by 60% to 80% of the preset value), it stops the operation of the water pump 206. At this time the absorber 201 starts to suck water up. Then the sucked water flows through the buffer water tank 202 into the boiler water tank and simultaneously the water flow rate is so regulated by adjustment of degree of openness of the motor valve 204 that the electric power applying to the electrode 100 is kept at the preset value (see Fig. 6).

Or without working of the absorber 201, only the pump 206 can act to supply water to the buffer water tank discontinuously.

If the detected electric power (or temperature or pressure) exceeds the preset value, it closes up the motor valves (203, 204) and opens the motor valve 205 to discharge water out of the boiler water tank, thereby lowering a level of water contacting with the working regions of the plates 101 of the electrode 100 to decrease electric power to keep electric power at the preset power value (or temperature or pressure) (see Fig. 7).

If the currefit sensed by the volt-ampere sensor is over the preset threshold current, the motor valves (203, 204, 205) are controlled by the controller 210 to decrease the electric power so that it ensures safety of the electric lines of the electric boiler.

And since the motor valve 205 is connected with a condenser, even if it stops operation of the electric boiler or in case of stoppage of power supply, it opens automatically by the aid of the condenser to discharge water contacting with the electrode 100, thereby the state of the electric boiler returns to the initial condition of operation.

If the controller 210 or motor valves (203, 204, 205) fails to work to exceed the preset value of power or temperature or pressure, the safety valve 301 and the explosive valve 302 acts to discharge water and steam out of the electric boiler, thereby the state of the electric boiler returns to the initial condition where electric power is zero (see Fig. 8).

All the motor valves, water pump and all the sensors are coupled with the controller 210, which is programmed to control the whole operation of the electric boiler in a principle of "constant power first - constant temperature (or pressure) afterwards". That is, the controller 210 first controls all the motor valves and the water pump to increase electric power until reached the preset power value, and after it comes to the preset power value, it controls all the motor valves in order to keep a pressure and a temperature of the electric boiler at the preset values. If the detected current exceeds the preset threshold current, it controls all the motor valves to decrease the electric power. Thereby the electric power, pressure, temperature and current are kept at the preset values under the control of the controller 210 (see Fig. 9).

And in case of an abnormal condition, it also controls the motor valves and water pump so that the state of the electric boiler returns to the initial condition, and then the user can start to re-operate the electric boiler from the beginning.

Although the preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the arts will appreciate that any various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. An active power automatic control system of an electric boiler comprising:

- an electrode (100) comprising several planar plates (101), insulating rings (102), a fastening rod (103) for plates (101), terminals (104) and lead wires (105), wherein each of the plates (101) is partitioned into a working region (107) coated with graphite and an insulated region (108) filmed with an insulating material, characterized that an area of the working region (107) is enough to provide the maximum electric power of the electric boiler, and the plates (101) are bundled up at equal distance by means of the insulating rings (102) installed in the insulated regions (108) and the fastening rod (103) which passes through openings of the insulating rings (102), and that the lead wires (105) are connected with the terminals (104) installed in the upper parts of the insulated regions (108);

- a power regulating device (200) comprising an absorber (201) which can suck water up discontinuously, a buffer water tank (202) which can supply the water sucked up by the absorber (201) to a boiler water tank continuously, motor valves (203, 204, 205), a water pump (206), check valves (207, 208), a controller (210) for controlling the motor valves (203, 204, 205) and the water pump (206), a volt-ampere sensor, a temperature sensor (221) and a pressure sensor (222); and

- a safety device (300) comprising a safety valve (301) and an explosive valve (302) which are both so installed at the main body of the electric boiler as to be positioned lower than the bottom of the electrode (100).

2. The active power automatic control system of the electric boiler according to claim 1 , wherein each of the plates (101) is further processed with a corrosion inhibitor and an adhesion reinforcing agent, and filmed with a parting agent.

3. The active power automatic control system of the electric boiler according to claim 1 , wherein edge insulated regions (106) are further formed around edges of the working regions of the plates (101) to prevent any abrasion of edges of the plates due to any edge discharge.

4. The active power automatic control system of the electric boiler according to claim 1, wherein the insulating ring (102) of each of the plates (101) is so designed as to minimize a distance between the plates (101) and maximize a current leakage path length thereof.

5. The active power automatic control system of the electric boiler according to claim 4, wherein a thickness of the insulating ring of each of the plates (101) ranges from 15 to 25 mm and the current leakage path length of it ranges from 50 to 100mm.

6. The active power automatic control system of the electric boiler according to claim 1 or 4, wherein the insulated region (108) of each of the plates (101) has such an enough area that a current leakage path length of it is longer than that of each of the insulating rings (102).

7. The active power automatic control system of the electric boiler according to claim 1 , wherein the plates (101) are parallel connected by the lead wires (105) to the three-phase power supply unit (400) so that the total area of the plates (101) contacting with water is maximized, thereby generating a large quantity of steam in a short time.

8. The active power automatic control system of the electric boiler according to claim 1, wherein even though the absorber (201) does not work, the water pump (206) is adapted to supply water to the buffer water tank (202) discontinuously.

9. The active power automatic control system of the electric boiler according to claim 1, wherein the absorber (201) is an injector.

10. The active power automatic control system of the electric boiler according to claim 1, wherein the absorber (201) comprises two condensation tanks which are so structured that when the motor valve (203) opens, steam flows down to the lower condensation tank and water of the lower condensation tank flows to the buffer water tank (202), and when it closes up, steam filled in the lower condensation tank flows up again into the upper condensation tank and the water of the upper condensation tank flows down to the lower condensation tank, and the while simultaneously sucking water up with the aid of vacuum by steam condensation and hydrodynamic vacuum.

1 1. The active power automatic control system of the electric boiler according to claim 1 , wherein the motor valve (205) is connected with a condenser, thereby even in case of power stoppage, it opens by itself to discharge water so that the state of the electric boiler returns to the initial condition of operation.

12. An operation method of the active power automatic control system according to any one of claims 1 to 1 1 includes following steps:

a) Turning the controller (210) on and setting up a predetermined electric power, temperature, pressure and a threshold current by use of a plurality of buttons of the controller;

b) Supplying electricity to the power supply unit (400) of the electric boiler;

c) Opening the motor valves (203, 204) and closing up the motor valve (205), and operating the water pump (206) to pump water up into the absorber (201) and then supplying the water through the buffer water tank (202) into the boiler water tank;

d) After the electric power reached by 60% to 80% of the preset power value, stopping operation of the water pump (206);

e) By only use of the absorber (201), sucking up and supplying water through the buffer water tank (202) into the boiler water tank, simultaneously with adjustment of a degree of openness of the motor valve (204) to regulate the supply of water in quantity, thereby keeping the electric power at the preset value;

f) If it exceeds the preset electric power, closing up the motor valves (203, 204) and opening the motor valve (205) to discharge water to decrease electric power;

g) Opening or closing up the motor valves (203, 204, 205) so as to keep a temperature (or a pressure) within the boiler at the preset temperature (or pressure);

h) When it exceeds the preset threshold current, closing up the motor valves (203, 204) and opening the motor valve (205) to discharge water to decrease electric power, and then repeating from step g;

i) If it stops the operation of the electric boiler or in case of power stoppage, opening the motor valve (205) (or it being opened by itself) to discharge water of the boiler water tank, so that the state of the electric boiler returns to the initial condition of operation where a current is zero; and

j) When an overpressure is formed within the boiler water tank due to failure of operation of the motor valves or the controller, the safety device (301, 302) acts by itself to discharge water and steam out of the boiler, so that the state of the electric boiler returns to the initial condition of operation.

13. The operation method of the active power automatic control system of the electric boiler according to claim 12, wherein the controller (210) is programmed to control the motor valves (203, 204, 205) and the water pump (206).