Control method and system of electrode hot water boiler

Abstract

The invention relates to a control method and system of an electrode hot water boiler, and belongs to the field of electrode hot water boiler control. When the electrode hot water boiler is ready to start, if the current boiler water temperature is lower than the first set temperature, the electrode hot water boiler does not supply heat to the outside and operates according to the first set power until the current boiler water temperature reaches the second set temperature; and then the electrode hot water boiler supplies heat to the outside, and the first set power is increased to the second set power according to the set step length. According to the invention, the electrode hot water boiler runs at a lower temperature and a safe power and does not supply heat to the outside, so that the electrode hot water boiler can effectively, quickly and stably reach the external heat supply condition.

Description

Technical Field

[0001] The invention relates to a control method and system for an electrode hot water boiler, belonging to the field of electrode hot water boiler control. Background Art

[0002] In many application scenarios of electrode hot water boilers, startup and operation stability are the first major indicators to measure the performance of electrode boilers. However, during the startup of the electrode hot water boiler, if it is the first time to start the boiler or the interval between the last startup and the last startup is long, the temperature of the boiler water is low due to the influence of the ambient temperature, and the conductivity is also low and unstable. If the boiler is started directly with a large power at this time, the boiler pressure and boiler temperature will change sharply during the power increase process, and the conductivity of the boiler water will also fluctuate. Since the operating power of the electrode hot water boiler is controlled by the PID controller, when the key parameters change, the operating power of the electrode hot water boiler will fluctuate greatly and the fluctuation time is very long, and the electrode hot water boiler needs a long time to operate stably. If the operating power fluctuates greatly and the protection limit setting is not much different from the power setting value, it is very likely to cause the temperature, pressure or power value of the electrode hot water boiler to exceed the limit, and then the protection is started to trip, resulting in a failure to start the boiler.

[0003] On the other hand, in some application scenarios that require electrode water boilers to respond quickly to reach the set power, such as participating in grid frequency and peak regulation or serving as a rapid consumption device for new energy power generation, electrode water boilers must be able to quickly reach the given power and be able to operate stably. Summary of the invention

[0004] The object of the present invention is to provide a control method and system for an electrode water boiler, so as to solve the problem that the electrode water boiler needs a long time to achieve stable operation when it is started when the boiler water temperature is low.

[0005] To achieve the above object, the solution of the present invention includes: A control method for an electrode water boiler of the present invention comprises the following steps when the electrode water boiler is ready to start: if the current boiler water temperature is lower than the first set temperature, the electrode water boiler does not supply heat to the outside and operates at the first set power until the current boiler water temperature reaches the second set temperature, thereby causing the electrode water boiler to supply heat to the outside and increase the power from the first set power to the second set power according to the set step length.

[0006] Furthermore, if the current boiler water temperature is greater than the first set temperature, the electrode hot water boiler supplies heat to the outside and increases from the third set power to the second set power according to the set step; the third set power is greater than the first set power.

[0007] Furthermore, during the process of the electrode water boiler supplying heat to the outside, when the current boiler water temperature is lower than the first set temperature, the electrode water boiler does not supply heat to the outside and operates at the first set power until the current boiler water temperature reaches the second set temperature, thereby causing the electrode water boiler to supply heat to the outside and increase from the first set power to the second set power according to the set step size.

[0008] Furthermore, when the electrode water boiler stops running, if the current boiler water temperature is lower than the third set temperature, the electrode water boiler does not supply heat to the outside but runs at the fourth set power until the current boiler water temperature reaches the fourth set temperature, and the electrode water boiler stops running; the third set temperature is higher than the second set temperature; the fourth set power is higher than the second set power.

[0009] Furthermore, whether the electrode hot water boiler supplies heat to the outside is realized by controlling the on-off of the three-way valve between the electrode hot water boiler and the heat exchanger; the heat exchanger includes two heat exchange ends, the first heat exchange end and the electrode hot water boiler constitute a heat cycle of boiler water, a bypass pipeline for bypassing the first heat exchange end is arranged between the water inlet and the water outlet of the first heat exchange end, and the boiler water is controlled to circulate back to the electrode hot water boiler from the bypass pipeline through the three-way valve, thereby realizing that the electrode hot water boiler does not supply heat to the outside; the second heat exchange end is used to supply heat to the user end.

[0010] A control system for an electrode hot water boiler includes a processor, and the processor executes a computer program to implement the following steps: When the electrode water boiler is ready to start: if the current boiler water temperature is lower than the first set temperature, the electrode water boiler does not supply heat to the outside and operates at the first set power until the current boiler water temperature reaches the second set temperature, and then the electrode water boiler supplies heat to the outside and increases from the first set power to the second set power according to the set step size.

[0011] Furthermore, if the current boiler water temperature is greater than the first set temperature, the electrode hot water boiler supplies heat to the outside and increases from the third set power to the second set power according to the set step; the third set power is greater than the first set power.

[0012] Furthermore, during the process of the electrode water boiler supplying heat to the outside, when the current boiler water temperature is lower than the first set temperature, the electrode water boiler does not supply heat to the outside and operates at the first set power until the current boiler water temperature reaches the second set temperature, thereby causing the electrode water boiler to supply heat to the outside and increase from the first set power to the second set power according to the set step size.

[0013] Furthermore, when the electrode water boiler stops running, if the current boiler water temperature is lower than the third set temperature, the electrode water boiler does not supply heat to the outside but runs at the fourth set power until the current boiler water temperature reaches the fourth set temperature, and the electrode water boiler stops running; the third set temperature is higher than the second set temperature; the fourth set power is higher than the second set power.

[0014] Furthermore, whether the electrode hot water boiler supplies heat to the outside is realized by controlling the on-off of the three-way valve between the electrode hot water boiler and the heat exchanger; the heat exchanger includes two heat exchange ends, the first heat exchange end and the electrode hot water boiler constitute a heat cycle of boiler water, a bypass pipeline for bypassing the first heat exchange end is arranged between the water inlet and the water outlet of the first heat exchange end, and the boiler water is controlled to circulate back to the electrode hot water boiler from the bypass pipeline through the three-way valve, thereby realizing that the electrode hot water boiler does not supply heat to the outside; the second heat exchange end is used to supply heat to the user end.

[0015] The beneficial effects of the present invention are as follows: the present invention is a pioneering invention. When the electrode hot water boiler of the present invention is ready to start, if the current boiler water temperature is lower than the first set temperature, the electrode hot water boiler does not supply heat to the outside and operates at the first set power until the current boiler water temperature reaches the second set temperature, and then the electrode hot water boiler supplies heat to the outside and increases from the first set power to the second set power according to the set step length. The present invention effectively enables the electrode hot water boiler to quickly and smoothly reach the external heating condition by operating at a safe power at a lower temperature and not supplying heat to the outside. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of an electrode hot water boiler system applicable to the present invention; Figure 2 The present invention is a schematic diagram of a start-up process of an electrode hot water boiler. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0018] The concept of the present invention is that when the temperature of the electrode water boiler is low, it is operated at a set power without external heat protection until the set temperature is reached. When the temperature is at the set temperature, the operating power is increased according to the set step size.

[0019] System Example: This embodiment provides a control system for an electrode water boiler. First, the overall architecture and working principle of the electrode water boiler are briefly introduced. Figure 1As shown in the figure, it consists of an electrode hot water boiler body and a primary circulation heat exchange system. The electrode hot water boiler body is composed of an inner cylinder and an outer cylinder. The electrode extends into the inner cylinder through an insulating protective porcelain sleeve, and the inner cylinder and the outer cylinder are also insulated from each other. When the liquid level in the inner cylinder is above the electrode, after the power supply supplies power to the electrode, the water itself acts as a conductor to interact thermally with the heating element. The heated hot water leaks into the outer cylinder through the liquid level control valve and is pumped to the primary heat exchange system through a circulating pump. The water after heat exchange is then circulated to the inner cylinder for heating. The liquid level in the inner cylinder is controlled by opening and closing the liquid level control valve to control the level of the liquid in the inner cylinder, thereby controlling the thermal power of the electrode hot water boiler. The higher the liquid level, the greater the thermal power. When the electrode hot water boiler has been running for a certain period of time, the conductivity of the water no longer meets the requirements, and the high conductivity water is discharged through the sewage pipe, and then the low conductivity water is replenished through the water supply pipe to maintain the safe and stable operation of the electrode hot water boiler (hereinafter referred to as the boiler).

[0020] The boiler water temperature is obtained through the temperature sensor at the temperature safety interlock, that is, the temperature of the outer cylinder water is obtained; when starting up for the first time or restarting after a long shutdown, the inner cylinder water temperature is consistent with the outer cylinder water temperature; during use, the inner cylinder water temperature is higher than the outer cylinder water temperature.

[0021] The boiler is connected to the water inlet of the primary side (first heat exchange end) of the heat exchanger through a water supply pipe. A circulation pump is installed in the water supply pipe. The water outlet of the primary side of the heat exchanger is connected to the boiler through a return water pipe, thereby forming a thermal circulation loop of boiler water. A three-way valve is connected in series on the return water pipe. The first port of the three-way valve is connected to the water outlet of the primary side of the heat exchanger, and the second port of the three-way valve is connected to the water supply pipe of the boiler, thereby forming a bypass pipeline. The third port of the three-way valve is connected to the return water pipe. The heat exchanger supplies heat and water through the water outlet of the secondary side (second heat exchange end), and supplies heat and return water through the water inlet of the secondary side.

[0022] The control system of the present invention includes a cold state heating system for an electrode hot water boiler, which is used when the electrode hot water boiler is started for the first time or when the interval between the last start-up and the start-up is long, and is activated by the boiler temperature parameter control. In order to enable the boiler to start smoothly and quickly at a lower boiler water temperature, a boiler cold state start-up program is set for the heating system, and the program is an embedded power PID controller.

[0023] like Figure 2As shown, when the boiler is ready to start: when the boiler water temperature in the boiler is higher than the first set temperature, the three-way valve is opened, the boiler supplies heat to the outside and increases from the third set power to the second set power according to the set step length; when the boiler water temperature in the boiler is lower than the first set temperature, the boiler cold start program is started, the first port of the three-way valve is closed, even if the boiler water flows back to the boiler from the outlet pipe through the bypass pipe, the boiler operates according to the first set power, so that the boiler only circulates and does not supply heat to the outside until the boiler water temperature reaches the second set temperature. At this time, the boiler has been warmed up, and various parameters are not much different from those in stable operation. Rapid adjustment according to the use demand will not cause large power fluctuations, and the set value can be quickly reached and the stable operation will be quickly achieved. Therefore, at this time, the first port of the three-way valve is opened, so that the boiler supplies heat to the outside and increases from the first set power to the second set power according to the set step length. Among them, the first set temperature and the second set temperature are set according to the actual required boiler water temperature and whether it can be started stably. For example, the first set temperature is 70°C and the second set temperature is 80°C. The cold start power parameter value can be adjusted according to the rated power of the boiler and actual usage, with the main purpose of being able to quickly warm up the furnace and achieve safe and stable operation during subsequent operation, but the third set power is greater than the first set power.

[0024] During the boiler heating process, the temperature of the water returning to the boiler may become very low, which will cause the boiler water to drop to a certain level. If the boiler is still operated at a higher power, it will affect the stability of the boiler operation. Therefore, during the operation of the boiler, when the boiler water temperature is lower than the first set temperature, the boiler cold start program is also started, that is, the boiler operates at the first set power but closes the three-way valve, so that the boiler only circulates and does not supply heat to the outside until the boiler water temperature reaches the second set temperature, and then opens the three-way valve to allow the boiler to supply heat to the outside and increase from the first set power to the second set power according to the set step length. In order to avoid the frequent start and stop of the boiler cold start program due to the back and forth changes in the boiler water temperature during the operation of the boiler, which may lead to the collapse of the system, there should be a certain gap between the first set temperature and the second set temperature, but the gap should not be too large, for example, the gap is 10°C.

[0025] The control system of the present invention also includes a heat retention system for an electrode hot water boiler, which is used when the boiler stops running after the heat release is completed, and is also activated by the boiler water temperature parameter control. When the boiler stops running, when the water temperature is lower than the third set temperature, the heat retention system is activated, the boiler does not supply heat to the outside and runs at the set heat retention power (fourth set power), and when the water temperature is higher than the fourth set temperature, the heat retention system fails and the boiler stops running. In this way, the boiler water temperature can be maintained at an optimal level. If an instruction to quickly start the boiler and reach a higher power is received at this time, the boiler can quickly and stably reach the limited power value for operation, and the third set temperature is greater than the second set temperature, and the fourth set power is greater than the second set power.

[0026] Method Example: This embodiment provides a control method for an electrode water boiler. The control system implemented using this method is such as the control system of the electrode water boiler introduced in the system embodiment. Since the introduction of the control system is clear enough, it will not be repeated here.

[0027] The use of this method enables the electrode hot water boiler to reach the warm-up state in a cold environment with low boiler temperature before load adjustment, avoiding the serious consequences of boiler oscillation, unstable operation, and even shutdown caused by excessively fast and large parameter changes during startup of the electrode hot water boiler, thereby ensuring the safety and stability of the boiler during startup and subsequent operation.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A control method for an electrode water boiler, characterized in that: When the electrode water boiler is ready to start, the following steps are included: if the current boiler water temperature is lower than the first set temperature, the electrode water boiler does not supply heat to the outside and operates at the first set power until the current boiler water temperature reaches the second set temperature, and then the electrode water boiler supplies heat to the outside and increases from the first set power to the second set power according to the set step size.

2. The control method of the electrode water boiler according to claim 1, characterized in that: If the current boiler water temperature is greater than the first set temperature, the electrode hot water boiler supplies heat to the outside and increases from the third set power to the second set power according to the set step size; the third set power is greater than the first set power.

3. The control method of the electrode water boiler according to claim 1, characterized in that: During the process of the electrode water boiler supplying heat to the outside, when the current boiler water temperature is lower than the first set temperature, the electrode water boiler does not supply heat to the outside and operates at the first set power until the current boiler water temperature reaches the second set temperature, thereby causing the electrode water boiler to supply heat to the outside and increase from the first set power to the second set power according to the set step size.

4. The control method of the electrode water boiler according to claim 1, characterized in that: When the electrode hot water boiler stops running, if the current boiler water temperature is lower than the third set temperature, the electrode hot water boiler does not supply heat to the outside but runs at the fourth set power until the current boiler water temperature reaches the fourth set temperature, and then the electrode hot water boiler stops running; the third set temperature is higher than the second set temperature; the fourth set power is higher than the second set power.

5. The control method of the electrode water boiler according to claim 1, characterized in that: Whether the electrode hot water boiler supplies heat to the outside is realized by controlling the on-off of the three-way valve between the electrode hot water boiler and the heat exchanger; the heat exchanger includes two heat exchange ends, the first heat exchange end and the electrode hot water boiler constitute a heat cycle of boiler water, a bypass pipeline for bypassing the first heat exchange end is arranged between the water inlet and the water outlet of the first heat exchange end, and the boiler water is controlled to circulate back to the electrode hot water boiler from the bypass pipeline through the three-way valve, thereby realizing that the electrode hot water boiler does not supply heat to the outside; the second heat exchange end is used to supply heat to the user end.

6. A control system for an electrode hot water boiler, comprising a processor, characterized in that: The processor executes the computer program to implement the following steps: When the electrode water boiler is ready to start: if the current boiler water temperature is lower than the first set temperature, the electrode water boiler does not supply heat to the outside and operates at the first set power until the current boiler water temperature reaches the second set temperature, and then the electrode water boiler supplies heat to the outside and increases from the first set power to the second set power according to the set step size.

7. The control system of the electrode water boiler according to claim 6, characterized in that: If the current boiler water temperature is greater than the first set temperature, the electrode hot water boiler supplies heat to the outside and increases from the third set power to the second set power according to the set step size; the third set power is greater than the first set power.

8. The control system of the electrode water boiler according to claim 6, characterized in that: During the process of the electrode water boiler supplying heat to the outside, when the current boiler water temperature is lower than the first set temperature, the electrode water boiler does not supply heat to the outside and operates at the first set power until the current boiler water temperature reaches the second set temperature, thereby causing the electrode water boiler to supply heat to the outside and increase from the first set power to the second set power according to the set step size.

9. The control system of the electrode water boiler according to claim 6, characterized in that: When the electrode hot water boiler stops running, if the current boiler water temperature is lower than the third set temperature, the electrode hot water boiler does not supply heat to the outside but runs at the fourth set power until the current boiler water temperature reaches the fourth set temperature, and then the electrode hot water boiler stops running; the third set temperature is higher than the second set temperature; the fourth set power is higher than the second set power.

10. The control system of the electrode water boiler according to claim 6, characterized in that: Whether the electrode hot water boiler supplies heat to the outside is realized by controlling the on-off of the three-way valve between the electrode hot water boiler and the heat exchanger; the heat exchanger includes two heat exchange ends, the first heat exchange end and the electrode hot water boiler constitute a heat cycle of boiler water, a bypass pipeline for bypassing the first heat exchange end is arranged between the water inlet and the water outlet of the first heat exchange end, and the boiler water is controlled to circulate back to the electrode hot water boiler from the bypass pipeline through the three-way valve, thereby realizing that the electrode hot water boiler does not supply heat to the outside; the second heat exchange end is used to supply heat to the user end.

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