Autonomous electric boiler

Abstract

The present invention relates to an autonomous electric boiler with high energy utilization rate and improved safety and operation convenience. The autonomous electric boiler of the present invention comprises: a steam generating cylinder (100) designed as a new structure equipped with an electrode (200); an output regulating device with a simple structure for regulating steam generation; and a safety device. The autonomous electric boiler of the present invention improves the initial steam generation speed and the autonomous output regulation capability based on the change of heat consumption on the load side, ensures the flexibility of setting and executing specific values ​​and the continuity of steam generation, thereby improving energy utilization rate. In addition, the ability to cope with over-output, over-current, over-pressure and voltage fluctuation is improved to ensure the safety and convenience of operation.

Description

Technical Field

[0001] The invention relates to an autonomous electric boiler. Background Art

[0002] So far, some autonomous control systems and operation methods for electric boilers have appeared, and autonomous electric boilers and electric water heaters applying these systems and methods have been disclosed, but their structures are complex, and their safety and convenience are not ideal.

[0003] The water supply device of the electric boiler disclosed in the patent authorized by the Democratic People’s Republic of Korea (authorized patent number KP56653) “Autonomous output automatic control system of electric boiler and its operation method” includes a water absorber, a buffer, an electric valve and a water pump or an ejector. However, due to its complex structure and control, it is inevitable to produce certain output fluctuations during normal operation, and the actuator often fails. In addition, in order to increase the initial steam generation speed, the electrode is constructed in a dense type and the steam generation cylinder is designed to be optimized, but because the electrode protection device for the above situation is not used, it is impossible to keep all phase currents consistent, and due to the influence of scale, if water with a hardness of 10 is used, maintenance is required every 120 to 150 hours of operation, resulting in the electrode life being limited to 3,000 to 5,000 hours of operation.

[0004] The water supply device disclosed in the patent authorized by the Democratic People’s Republic of Korea (authorized patent number KP60290) “Autonomous steam and hot water combined generating device” is relatively simple in that it consists of a water pump, an electric valve, and a check valve. However, when supplying water, the flow rate entering the steam generating cylinder needs to be adjusted by a water pump and an electric valve, so the control is complicated and there are many failure factors.

[0005] In previous electrode-type electric boilers and the devices disclosed in the above-mentioned documents, the steam generating cylinder is vertical. Therefore, an electric boiler with an output of 100kW can only start operating after at least 50L of water flows into it. The initial steam generation time is about 3 to 5 minutes, and the electrodes can only be repaired and the steam generating cylinder cleaned after the electrodes are disassembled.

[0006] In order to overcome the shortcomings of electric boilers as described above, the purpose of the present invention is to provide a steam generating cylinder with a new structural design, a simple output regulating device for regulating steam generation, and a safety device to improve the performance and energy utilization of autonomous electric boilers, and to improve safety and operational convenience.

[0007] That is, through the new steam generating cylinder structure, the volume of the steam generating cylinder is further optimized to shorten the initial steam generating time, reduce energy loss, protect the electrode, and ensure conditions conducive to electrode maintenance. In addition, a new output regulating device with a simple structure is applied to reduce device failure factors, extend the electrode maintenance cycle and life, ensure the convenience of operation, and quickly respond to the heat consumption on the load side, and generate steam according to the amount required by the heat consuming object to maximize energy utilization. In addition, safety devices are added to improve the safety of electric boilers. Summary of the invention

[0008] The autonomous electric boiler of the present invention comprises: a steam generating cylinder designed as a new structure equipped with electrodes; an output regulating device with a simple structure for regulating steam generation; and a safety device.

[0009] The new steam generating cylinder is a horizontal cylindrical structure, including a compartment and an electrode chamber. The compartment has a space for water to stay for a specified time and be softened twice, and the electrode chamber has a space for electrodes to be set. The compartment and the electrode chamber are separated by a partition, and the water pipe in the compartment connects the upper part of the compartment with the lower part of the electrode chamber. When the electrode is set in the electrode chamber, an electrode protection plate is set at the lower part of the electrode. The closest gap between the cylinder body of the steam generating cylinder and the electrode is 35 to 100 mm. The steam generating cylinder has such a characteristic structure, which optimizes the volume of the steam generating cylinder and reduces the amount of water directly contacting the electrode to a minimum, thereby shortening the initial steam generation time. Even if it is restarted during operation, the initial steam generation time can be shortened with the help of the heated water in the compartment. In addition, the electrodes can be repaired and the steam generating cylinder can be cleaned without disassembling the electrodes.

[0010] The electrode has an operating range that can achieve maximum output even in soft water with the lowest conductivity. It consists of more than six flat electrode plates with a resistance of less than 10Ω arranged in parallel at intervals of 10 to 30 mm, and the width of the insulation area on both sides and the bottom is 5 to 10 mm. The electrode is designed to densely arrange the flat electrode plates, so as to minimize the electrode installation space. Not only can the output be adjusted according to the length of the electrode immersed in water, but the electrode resistance is limited to a specified range, thereby minimizing the power consumption caused by heating the electrode plate and maximizing the amount of steam generated based on power consumption. In addition, in order to prevent the current focusing phenomenon generated at the edge of the electrode, the parts on both sides and the bottom of the electrode plate, about 5 to 10 mm from the edge, are insulated to ensure the uniformity of the current density.

[0011] The output regulating device includes an auxiliary water cylinder, a water pump, a shut-off and regulating valve, a check valve, a float valve, a solenoid valve, a filter, a circulation pipe, a control board, a voltage and current sensor part, a pressure sensor part and a temperature sensor part.

[0012] The safety device comprises a water pump, a circulation pipe, a solenoid valve, a safety valve, an explosion valve and an AC contactor or an air circuit breaker. The safety valve and the explosion valve are arranged outside the electrode chamber and below the bottom surface of the electrode.

[0013] The upper end of the partition is located on the upper side of the electrode operation area, the upper end of the water pipe is slightly lower than the upper end of the partition, and the lower end of the water pipe is arranged at the lower part of the partition.

[0014] The electrode chamber is provided with an electrode protection plate, which is set more than 30 mm away from the bottom surface of the electrode to ensure the uniformity of the phase current and prevent electrochemical corrosion of the steam generating cylinder caused by grounding current. A specified DC voltage is also applied to prevent electrochemical corrosion of the electrode.

[0015] The auxiliary water cylinder of the output regulating device of the present invention is an open cylinder for supplying water to the steam generating cylinder, and is provided with a water supply pipe, a circulation pipe, and a condensed water recovery pipe, and the circulation pipe is connected to the lower part of the electrode chamber. The auxiliary water cylinder is connected to the lower part of the compartment through a filter, a water pump, a first regulating valve, and a check valve, and is also connected to the outlets of the safety valve, the explosion valve, and the solenoid valve. A first stop valve and a float valve are provided in the water supply pipe, and a second regulating valve is provided in the circulation pipe.

[0016] The water pump is connected to the bottom surface of the compartment, and a check valve and a first regulating valve are arranged between the water pump and the compartment. The water pump supplies water to the electrode chamber through the compartment according to the set value (output, current, temperature, pressure), the first regulating valve adjusts the flow into the compartment, and the check valve prevents the water in the compartment from flowing out to the auxiliary water cylinder. The filter filters the water in the auxiliary water cylinder and sends it to the compartment.

[0017] The circulation pipe is a pipe connecting the lower part of the electrode chamber and the auxiliary water cylinder. It is provided with a second regulating valve. When operating normally, the impurities in the electrode chamber are sent to the auxiliary water cylinder, and the water entering the auxiliary water cylinder is heated to soften it. When working safely, as long as the water pump stops, the current, output and pressure are reduced. The water softened once in the circulation pipe is filtered through the filter and enters the compartment. After staying in the compartment for a specified time and being softened by the heat generated by the electrode chamber for a second time, it flows into the lower part of the electrode chamber. The heated water flows out to the auxiliary water cylinder together with the impurities. This process is carried out continuously, the impurities in the electrode chamber are removed in real time, and the water is softened and filtered for a second time, thereby preventing the electrode from being damaged and the performance from being degraded due to impurities. In addition, by recirculating part of the water in the electrode chamber, the output fluctuation during water supply can be reduced. In addition, a condensate recovery pipe is provided in the auxiliary water cylinder to recover the condensate generated on the load side. The condensate recovery pipe does not require a water pump, and the condensate generated on the load side can also enter the auxiliary water cylinder. The float valve provided in the water supply pipe is closed to cut off the water supply. When all the generated steam turns into condensed water, the float valve arranged in the water supply pipe is automatically closed so that the water supply is not used, and the second regulating valve arranged in the circulation pipe is closed without recirculation.

[0018] The solenoid valve is a device that discharges water outward according to the control board signal when the output (or current, pressure, temperature) of the electrode chamber exceeds the set value. Its inlet is connected to the electrode chamber of the steam generating cylinder from the lower part of the electrode plate, and the outlet is connected to the outside or the auxiliary water cylinder. A second stop valve is provided between the solenoid valve and the electrode chamber, so that the electronic valve can be repaired without causing obstacles to normal operation.

[0019] The control panel is equipped with a PLC or a single-chip microcomputer. Based on the measured values ​​and outputs of the voltage, current sensor unit, temperature sensor unit, and pressure sensor unit, the current limit value, the temperature, and the preset values ​​of the pressure, the water pump and the solenoid valve of the output regulating device are controlled according to the principle of "stabilizing the output first and then stabilizing the temperature (or pressure)" to adjust the output so that the electric boiler maintains the specified temperature (or pressure). The pressure sensor unit and the temperature sensor unit can measure the pressure of the boiler and the temperature on the load side, respectively, and generate steam according to the needs of the load side. In addition, the control panel automatically controls the safety device.

[0020] In the safety device of the present invention, the water pump, electromagnetic valve, AC contactor or air circuit breaker works according to the signal of the control panel, while the safety valve and explosion valve work independently of the signal and work when the pressure reaches a specified critical value.

[0021] All structures and devices of the autonomous electric boiler of the present invention adjust the current of the electrode by a current change of 10 to 150A every time the water level in the working area of ​​the electrode changes by 1mm, thereby adjusting the output according to the height of the electrode immersed in water.

[0022] The advantage of the present invention is that it has an instant steam generation function, that is, the steam of the set output can be generated within at least 1 minute after the power is turned on and the current starts to rise from zero.

[0023] In addition, the corresponding steam generation is ensured in real time according to the changes in pressure and temperature set in response to the changes in heat consumption on the load side.

[0024] In addition, it has multiple safety functions, so it can stably generate steam at the set value without being affected by voltage, frequency fluctuations and water hardness.

[0025] In addition, the steam generating cylinder is a horizontal cylinder with compartments and uses an electrode protection plate to reduce the impact of scale, increase the life and safety of the electrode, and ensure the convenience of electrode plate maintenance. Compared with existing devices, the electrode maintenance cycle and life are extended to 10 times and 2 to 5 times respectively.

[0026] In addition, the water supply device is simplified to reduce output fluctuations and failure rates during normal operation; an auxiliary water cylinder is used to soften and filter the water to ensure the recycling of condensed water.

[0027] In addition, it can be installed close to the load side to reduce heat loss in the pipeline and heat loss caused by the pressure required for steam transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A , Figure 1B It is a structural diagram of the autonomous electric boiler of the present invention.

[0029] Figure 2 Shows the structure of the electrode.

[0030] Figure 3A , Figure 3B The output regulation process of the autonomous electric boiler of the present invention is shown.

[0031] Description of Reference Numerals

[0032] 100: Steam generating cylinder 110: Compartment

[0033] 111: Water pipe 112: Partition

[0034] 120: Electrode chamber 130: Electrode protection plate

[0035] 200: Electrode 201: Working area

[0036] 202: Insulation area

[0037] 310: Auxiliary water cylinder

[0038] 311: Float valve 312: First stop valve

[0039] 313: Water supply pipe 314: Condensate recovery pipe

[0040] 320: Water pump 321: First regulating valve

[0041] 322: Check valve 323: Filter

[0042] 330: Circulation pipe 331: Second regulating valve

[0043] 340: Solenoid valve 341: Second stop valve

[0044] 350: Control board 351: Current and voltage sensor unit

[0045] 352: Pressure sensor unit 353: Temperature sensor unit

[0046] 401: Safety valve

[0047] 402: Explosion valve 403: AC contactor or air circuit breaker

[0048] 500: Water return valve DETAILED DESCRIPTION

[0049] The structure of the autonomous electric boiler, the output regulation process, and the working process of the safety device of the present invention are described in detail below in conjunction with the accompanying drawings.

[0050] like Figure 1A , Figure 1B As shown, the autonomous electric boiler of the present invention comprises a steam generating cylinder 100 equipped with an electrode 200, an output regulating device and a safety device.

[0051] The steam generating cylinder 100 includes a compartment 110 and an electrode chamber 120. The steam generating cylinder 100 is designed as a horizontal cylindrical structure, which enables an electric boiler with an output of 100 kW to start generating steam with 15 L of water, thereby shortening the initial steam generation time to about 0.5 to 1 minute. Only about 10 L of the 15 L of water enters the electrode chamber 120 for operation.

[0052] The water conduit 111 connects the upper part of the compartment 110 and the lower part of the electrode chamber 120, so the impact on the initial steam generation is small. The water in the compartment 110 is still maintained after restarting, so even if low-temperature water enters the compartment 110, the heated water will still enter the electrode chamber 120, thereby shortening the steam generation time.

[0053] like Figure 2 As shown, the electrode 200 is composed of several flat electrode plates arranged at equal intervals, and each electrode plate is divided into an operating area 201 and an insulating area 202.

[0054] The working area 201 has an area that can ensure the maximum output when working in soft water with the lowest conductivity. The width of the insulating area 202 on both sides and the bottom is set to 5 to 10 mm to prevent the current focusing phenomenon generated at the edge of the electrode plate so that the current flowing in each electrode plate remains consistent. The resistance of each electrode plate and the working area 201 is ensured to be within the specified range to minimize the current loss in the middle.

[0055] like Figure 3A , Figure 3B As shown, water entering the compartment 110 flows into the lower part of the electrode chamber 120 through the water conduit 111 at the upper part of the compartment 110. In this way, the retention time of water in the compartment 110 and the electrode chamber 120 is prolonged when water is supplied, so that the water is heated and softened, thereby reducing electrode damage and performance degradation caused by scale, providing favorable conditions for repairing the electrodes.

[0056] The output regulation process of the autonomous electric boiler of the present invention is specifically as follows:

[0057] The control panel 350 is powered on, and the output, temperature, pressure, and current limit values ​​of the control panel 350 are set to predetermined values. After the control panel 350 is powered on, the solenoid valve 340 is opened, and the water in the electrode chamber 120 flows out to ensure the safety of the initial operation. After the setting is completed, press the operation key to start the operation. At this time, after the main power is connected through the AC contactor or the air circuit breaker 403, the water pump 320 is started, and the water in the auxiliary water cylinder 310 is sent to the compartment 110, and then the water in the compartment 110 enters the electrode chamber 120 through the water pipe 111. The water in the electrode chamber 120 contacts the electrode 200 and starts to generate steam. When the output reaches the critical value of 30-40% of the set output, the water pump 320 is stopped, and the output rise degree is observed for 30 seconds, and then the water pump 320 is started to reach the output setting value. If the measured value reaches the set value, the water pump 320 is stopped, and if the measured value is lower than the set value, the water pump 320 is started again to increase the output. At this time, the error between the measured value and the set value does not exceed the range of ±5%. Once the operation starts, part of the water entering the electrode chamber 120 flows into the auxiliary water cylinder 310 through the circulation pipe 330, and at this time, part of the impurities in the electrode chamber 120 also flow out. In addition, the feed water entering the auxiliary water cylinder 310 is softened after being heated once, and the filtered water is sent to the compartment 110 through the filter 323 set at the front end of the water pump 320. The water flowing into the compartment 110 is retained for a certain period of time, and is softened again by high heat, and enters the electrode chamber 120 through the water pipe 111. Steam is generated and supplied according to the set output. When the pressure or temperature on the load side reaches the set value, the start and stop of the water pump 320 is adjusted to reduce the output, so that the pressure or temperature can be stabilized during operation. All the above processes are automatically performed by the control panel.

[0058] The working process of the safety device of the autonomous electric boiler of the present invention is as follows:

[0059] First, when any measured value exceeds the limit range of the set value during operation, the water pump 320 is stopped. In this way, the water in the electrode chamber 120 can only flow out through the circulation pipe 330 but cannot enter, and the current, output, and pressure drop at the same time. If this process is not executed smoothly, or if it cannot drop to the set value within the required time after execution, the solenoid valve 340 is opened to discharge the water in the electrode chamber 120. If the above two safety operations are not executed smoothly and the measured value is at the dangerous critical value of the equipment, the main power supply is cut off by disconnecting the AC contactor or the air circuit breaker 403. In this way, the current and output become zero, and as mentioned above, the water flows out through the circulation pipe 330 and the pressure also drops. The above process is automatically performed by the control panel 350. If none of the automatic safety devices work, any one of the safety valve 401 and the explosion valve 402 connected to the electrode chamber 120 works to discharge the water in the electrode chamber 120 to ensure the safety of the autonomous electric boiler.

Claims

1. An autonomous electric boiler, comprising a steam generating cylinder (100) equipped with an electrode (200), an output regulating device and a safety device, It is characterized in that The steam generating cylinder (100) is a horizontal cylindrical structure, comprising a compartment (110) and an electrode chamber (120), wherein the compartment (110) has a space for allowing water to be retained for a specified time and softened twice, and the electrode chamber (120) has a space for arranging the electrode (200), the compartment (110) and the electrode chamber (120) are separated by a partition (112) and communicated with a water conduit (111), an electrode protection plate (130) is arranged in the electrode chamber (120), and the closest gap between the cylinder body of the steam generating cylinder (100) and the electrode (200) is 35 to 100 mm; The electrode (200) has an operating area (201) capable of achieving maximum output even in soft water with the lowest conductivity, and is composed of more than six flat electrode plates with a resistance of less than 10Ω arranged in parallel at intervals of 10 to 30 mm, and the width of the insulating area (202) on both sides and the bottom is 5 to 10 mm; The output regulating device comprises an auxiliary water cylinder (310), a water pump (320), a stop and regulating valve, a check valve (322), a float valve (311), a solenoid valve (340), a filter (323), a circulation pipe (330), a control panel (350), a voltage and current sensor unit (351), a pressure sensor unit (352) and a temperature sensor unit (353); The safety device comprises the water pump (320), the circulation pipe (330), the solenoid valve (340), a safety valve (401), an explosion valve (402) and an AC contactor or an air circuit breaker (403); the safety valve (401) and the explosion valve (402) are arranged outside the electrode chamber (120) and below the bottom surface of the electrode (200).

2. The autonomous electric boiler according to claim 1, It is characterized in that The upper end of the partition (112) is located on the upper side of the operating area (201) of the electrode (200), the upper end of the water pipe (111) is slightly lower than the upper end of the partition (112), and the lower end of the water pipe (111) is arranged at the lower part of the partition (112).

3. The autonomous electric boiler according to claim 1, It is characterized in that The electrode protection plate (130) is disposed at a distance of more than 30 mm from the bottom surface of the electrode (200) and is applied with a direct current voltage to prevent electrochemical corrosion of the electrode (200).

4. The autonomous electric boiler according to claim 1, It is characterized in that The auxiliary water cylinder (310) is provided with a water supply pipe (313), a circulation pipe (330), and a condensed water recovery pipe (314); the circulation pipe (330) is connected to the lower part of the electrode chamber (120); the auxiliary water cylinder (310) is connected to the lower part of the compartment (110) through the filter (323), the water pump (320), the first regulating valve (321), and the check valve (322), and is also connected to the outlets of the safety valve (401), the explosion valve (402), and the solenoid valve (340).

5. The autonomous electric boiler according to claim 4, It is characterized in that The water pump (320) is connected to the bottom surface of the compartment (110), and the check valve (322) and the first regulating valve (321) are provided between the water pump (320) and the compartment (110).

6. The autonomous electric boiler according to claim 1, It is characterized in that The circulation pipe (330) is provided with a second regulating valve (331). When operating normally, the impurities in the electrode chamber (120) are sent to the auxiliary water cylinder (310) in real time, and the water entering the auxiliary water cylinder (310) is heated and softened. When working safely, as long as the water pump (320) stops, the current, output and pressure are reduced.

7. The autonomous electric boiler according to claim 4, It is characterized in that The condensed water recovery pipe (314) does not require the water pump (320), and can also allow the condensed water generated on the load side to enter the auxiliary water cylinder (310), and the float valve (311) arranged on the water supply pipe (313) is closed to cut off the water supply.

8. The autonomous electric boiler according to claim 1, It is characterized in that The electromagnetic valve (340) is connected to the electrode chamber (120) from the lower part of the electrode plate, and a second stop valve (341) is provided between the electrode chamber (120) and the electromagnetic valve (340).

9. The autonomous electric boiler according to claim 1, It is characterized in that The pressure sensor unit (352) and the temperature sensor unit (353) of the output regulating device can measure the pressure of the boiler and the temperature on the load side, respectively.

10. The autonomous electric boiler according to claim 1, It is characterized in that All structures and devices of the autonomous electric boiler adjust the current of the electrode (200) by a current change of 10 to 150 A every time the water level in the operating area (201) of the electrode (200) changes by 1 mm, thereby adjusting the output according to the height of the electrode (200) immersed in water.

Images