KR20000032712A - Method of sensing running out of water of gas boiler - Google Patents

Abstract

PURPOSE: A sensing method of running out of water is provided to prevent the damage of a heat exchanger due to overheating and the damage of a pump by sensing the running out of water by installing a thermistor in a bypass pipe connected to an expansion tank and to a heating water pipe inserted to a heat exchanger. CONSTITUTION: A procedure of combustion in a heating part is sensed by using an infrared sensor, and a signal is transmitted to a temperature detecting and storing step(S2). The temperature of the heating water passing through a bypass pipe is detected by using a thermistor installed in the bypass pipe by the signal of the ignition sensing step(S1). A signal is transmitted to a set up time elapsed step(S3). If the set up time is not elapsed, a signal is transmitted to the temperature detecting and storing step by deciding the elapse of the set up time. The temperature is continuously detected and stored. If the set up time is elapsed, a signal is transmitted to a step(S4) for comparing temperature fluctuation per unit time. If the rate of temperature fluctuation is over zero, a signal is transmitted to a normal operation step(S5). If the rate of temperature fluctuation is the same as or under zero, a signal is transmitted to a step(S6) for stopping operation and indicating an error. Then, the operation of a boiler is maintained. After stopping the operation of the boiler, the disorder of a float switch and the running out of water in the boiler is displayed on the display window of a room controller.

Description

How to detect no water in gas boiler

The present invention relates to a method of detecting no water in a gas boiler, and more particularly, by installing a thermistor on a bypass pipe connected to a heating water pipe and an expansion tank introduced into a heat exchanger, and measuring a temperature change after ignition of a burner of a heating unit. The present invention relates to a gas boiler water detection method that prevents damage to the heat exchanger due to overheating and damage to the pump due to operation in the absence of water.

In general, domestic gas boilers are designed to reduce the size of large boilers used for industrial purposes and add various control functions to supply heating and hot water in general households due to the development of heat engines. At first, coal or oil was used as a fuel to operate the boiler, but as the supply of city gas became more common, the demand for gas boilers increased rapidly.

Such household gas boilers are divided into various types according to the installation type, the hot water supply method, the exhaust method, and the circulation of the heating water. However, the domestic gas boilers are generally divided according to the installation type and the hot water supply method. As described above, it is divided into a wall-mounted type and a floor-mounted type according to the installation type, and divided into an instant type and a water type according to the hot water supply method.

1 is a schematic view of a conventional gas boiler. Referring to the structure of a general gas boiler with reference to the drawings, the interior of the domestic gas boiler is a gas pipe, a heating supply pipe, a heating return pipe, a direct water pipe, and a hot water pipe. The gas pipe is equipped with a gas valve (5) for controlling the supply of gas, and burner (4) ignited by the transformer (6) to burn the gas flowed through the gas pipe to obtain heat The built-in heating part 2 is attached. The upper part of the heating part 2 is integrally coupled to the heat exchanger 3 piped with the heating tube and the hot water pipe alternately, and the internal combustion action of the heating part 2 is applied to the upper part of the heat exchanger 3. Inlet port 14, exhaust port 15 and fan 16 are mounted for smoothing.

The expansion tank 9 equipped with the float switch 10 for detecting the water level is connected to a supplemental water pipe equipped with a heating supply pipe, a heating return pipe, an overflow pipe, and a supplemental water valve 11. And the other end of the supplemental water pipe is connected to the straight pipe. The overflow pipe is discharged out of the water to maintain a constant pressure in order to prevent the failure of other components when the volume expansion of water occurs due to the temperature rise.

The heat exchanger 3 is piped with a heating water pipe, a direct water pipe and a hot water pipe, and the heating water pipe (part connected to the heating supply pipe) has a temperature sensor for preventing overheating of the boiler 1 at a position close to the heat exchanger 3. (8) is attached. In addition, the boiler 1 is also equipped with a three-way valve 12 for switching the flow of the heating water in the heating mode / hot water mode and a pump 7 for generating the flow of water to the heat exchanger (3) The flow pipe 13 is mounted on the water pipe to detect the flow of water. In addition, the switch, the sensor and the valve serves as a safety device to prevent the risk caused by the abnormal operation of the boiler.

However, when the heating water does not detect the absence of the heating water in the pipe piped in the boiler 1 due to a malfunction or failure of the float switch 10, the pump 7 is ignited and starts combustion. Even if damage occurs and the operation of the boiler 1 is stopped by the temperature sensor 8 for preventing overheating, the heat exchanger 3 causes damage by overheating before the temperature sensor 8 detects overheating. In this case, the cost of repairing the boiler 1 is caused.

Accordingly, an object of the present invention is to solve the above-mentioned drawbacks, and to measure the temperature change after the ignition of the burner of the heating unit by mounting the thermistor in the bypass pipe connected to the heating water pipe introduced into the expansion tank and the heat exchanger to detect the absence of water. It is to provide a gas boiler water detection method to prevent damage to the heat exchanger due to overheating and pump damage due to operation in the absence of water.

Features of the present invention for achieving the above object, the ignition detection step of transmitting a signal to the temperature detection and storage step by detecting whether the combustion is in progress in the heating unit using an infrared sensor; A temperature detection and storage step of detecting and storing a temperature of the heating water passing through the bypass pipe by using the thermistor mounted to the bypass pipe by the signal of the ignition detection step, and transmitting a signal in a set time elapsed step; It is determined whether the set time has elapsed by the signal of the temperature detection and storage step, and if the set time has not elapsed, the signal is sent to the temperature detection and storage step to continuously detect and store the temperature, and if the set time has elapsed, the temperature per hour A set time elapsed step of transmitting a signal to a change comparison step; If the temperature change rate over time is greater than zero by the signal of the set time elapsed time, the signal is sent to the normal operation step.If the temperature change rate over time is less than or equal to zero, it stops and displays the error. An hourly temperature change comparison step of transmitting a signal; A normal operation step of continuously maintaining the operation state of the boiler by the signal of the temperature change comparison step per hour; And stopping the operation of the boiler by the signal of the temperature change comparison step per hour, and stopping the water and indicating the absence of water in the boiler on the display window of the room cone. Is in.

1 is a partial cross-sectional view schematically showing the interior of a conventional gas boiler,

2 is a schematic circuit diagram of a gas boiler equipped with a thermistor in a bypass tube for carrying out the method according to the invention,

3 is a block diagram showing essential components for practicing the method of the present invention,

4A and 4B are graphs showing a change in temperature with time detected by the thermistor with and without water, respectively.

5 is a flowchart illustrating a control method of the present invention.

* Explanation of symbols on the main parts of the drawings *

S1 ... Ignition Detection S2 ... Temperature Detection and Storage

S3 ... setting time elapsed step S4 ... comparing temperature change per hour

S5 ... Normal operating step S6 ... Stopping and error display steps

A ... control unit i ... driving unit

Da ... ignition detector d ... time detector

T ... display bar ... temperature detector

Referring to FIG. 2, a schematic operation state will be described with reference to FIG. 2. When the boiler 100 starts initial driving, one end is connected to a straight pipe at the bottom of the floor sensor 107, and the other end is connected to the expansion tank 111. Water replenishment is made into the expansion tank 111 through the connected supplemental water pipe, and then the gas valve 105 is opened, and gas is introduced into the heating unit 101 through the gas pipe and burned to pass through the heat exchanger 102. Raise the temperature of the water or hot water. This combustion state is detected by the infrared sensor 109, the supply of heating water and hot water is controlled by a three-way valve. During this process, if the heating water is insufficient due to the temperature rise of the heat inductor 102, water is replenished through the supplementary water pipe. However, if this water shortage is not detected due to a failure of the float switch 110 mounted on the expansion tank 111, the heat exchanger 102 and the pump 104 generating the flow of the heating water cause a failure, thereby expanding. The thermistor 112 is mounted on the bypass pipe connected to the heating water pipe inserted into the tank 111 and the heat exchanger 102 to sense the temperature change.

The boiler 100 for carrying out the method according to the present invention includes a control unit (A), a driving unit (B), and an ignition detecting unit (C) to control the operation of the boiler 100 through the temperature change detected by the thermistor 112. ), A time detector (d), a display (e), and a temperature detector (bar) are essential.

The temperature change as described above is because there is no movement of water from the hot water pipe inserted into the heat exchanger 102 to the expansion tank 111 through the bypass pipe when there is no water in the boiler 100 as shown in FIGS. 4A and 4B. The thermistor 112 mounted on the pass pipe cannot detect the temperature change, and maintains the initial temperature for a predetermined time as shown in the graph of FIG. 4B. After a predetermined time has elapsed, the temperature starts to rise sharply by the conduction heat due to the heat conduction according to the temperature rise of the heat exchanger 102. However, when there is no thermistor 112, when the temperature sensor 108 for preventing overheating starts to detect the temperature change according to the conduction heat, the heat exchanger 102 or the pump 104 will already be damaged. .

And, if the water is sufficient in the boiler 100, since the water is introduced into the expansion tank 111 through the bypass pipe, the thermistor 112 obtains the same result as the graph of FIG. 4A. That is, the temperature rises gradually as time passes from the initial heating of the heat exchanger 102. The control method of the present invention uses this result to control overheating in the absence of water in the boiler 100 through the steps as shown in FIG. 5.

When the gas valve 105 enters the gas through the open gas pipe and starts combustion in a burner (not shown) of the heating unit 101, the combustion flame of the infrared sensor 109 is detected in the ignition detection step (S1). The signal is sent to the temperature detection and storage step (S2). In the temperature detection and storage step (S2) by such a signal, the temperature of the water flowing into the expansion tank 110 through the bypass pipe from the hot water pipe inserted into the heat exchanger 102 is detected and stored using the thermistor 112. The signal is sent to the set time elapsed step S3.

In the set time elapsed step (S3), a timer is used to delay until a predetermined time passes, and when the set time elapses, a signal is sent to a step (S4) for comparing a change in temperature over time. In this way, the delay of the signal flow for a predetermined time in the set time elapsed step (S3) is that the heat of the heat exchanger 102 generated by the combustion in the heating unit 101 by the heating water passing through the bypass pipe (thermistor ( 112). This delay time should be set in consideration of the minimum operating time of the boiler 100 according to the set temperature and the damage of the heat exchanger 102 and the pump 104 generated by heating in the absence of water, and the capacity of a general boiler Considering about 1 minute is preferable. If the above time has not elapsed in the set time elapsed step S3, a signal is sent to the temperature detection and storage step S2 to continuously measure and store the temperature in the thermistor 112.

In the temperature change per hour determination step (S4) by the signal sent after the set time elapses, it is determined whether the temperature change rate per hour has a number greater than zero. Since it indicates a sufficient state, it sends a signal to the normal operation step (S5) to continue to drive the boiler 100 normally. However, if the rate of change in temperature per hour is zero or less, this indicates that there is no water in the boiler 100, which stops the operation of the boiler 100 and also causes the float switch 110 to appear on the display of the room cone (not shown). ) Indicates an error and no water.

The method of detecting the absence of water in the boiler 100 according to a series of steps when the floor switch 110 is inoperable or malfunctions as described above when the boiler 100 is initially operated or in a continuous operating state. You can do it at any time.

According to the present invention as described above, the thermistor is mounted on the bypass pipe connected to the heating water pipe and the expansion tank introduced into the heat exchanger to measure the temperature change after the ignition of the burner of the heating unit to detect the absence of water float switch In the event of inoperability or breakdown, there is an effect that can prevent damage to the heat exchanger due to overheating and pump damage due to operation in the absence of water.

Claims (2)

In the gas boiler having a heating pipe introduced into the heat exchanger 102 and a bypass pipe connected to the expansion tank 111, An ignition detection step S1 of detecting whether combustion is in progress in the heating unit 101 using the infrared sensor 109 and sending a signal to the temperature detection and storage step S2; By using the thermistor 112 mounted on the bypass pipe by the signal of the ignition detection step (S1) to detect and store the temperature of the heating water passing through the bypass pipe and to send the signal to the set time elapsed step (S3) Temperature detection and storage step S2; It is determined whether the set time has elapsed by the signal of the temperature detection and storage step S2. If the set time has not elapsed, the signal is sent to the temperature detection and storage step S2 to continuously detect and store the temperature, and then set the time. When the elapsed time elapses the set time elapsed step (S3) for transmitting a signal to the temperature change comparison step (S4); When the rate of change of temperature over time is greater than zero by the signal of the set time elapsed step (S3), the signal is sent to the normal operation stage (S5), and when the rate of change of temperature over time is less than or equal to zero, it operates. An hourly temperature change comparison step (S4) for transmitting a signal to the stop and error display step (S6); Normal operation step (S5) to maintain the operating state of the boiler 100 by the signal of the temperature change comparison step (S4) per hour; And The operation of the boiler 100 is stopped by the signal of the temperature change comparison step S4 per hour, and the operation and error of displaying the failure of the float switch 110 and the absence of water in the boiler 100 on the display window of the room cone. Method for detecting no water in the gas boiler consisting of a display step (S6). The method of claim 1, wherein the setting time of the set time elapsed step (S3) is 60 seconds.