Air heater pipeline anti-freezing system and air heater system

Abstract

The utility model discloses an air heater pipeline anti-freezing system and an air heater system, and relates to the technical field of boiler warm air, the air heater pipeline anti-freezing system comprises a main pipeline, the main pipeline is sequentially provided with a booster pump, a first electromagnetic valve, a second electromagnetic valve and a low-pressure heating part; the bypass pipeline is communicated with the main pipeline, the communication position of the bypass pipeline and the main pipeline is located between the first electromagnetic valve and the second electromagnetic valve, and a first valve is arranged at the end, close to the main pipeline, of the bypass pipeline. One end, far away from the main pipeline, of the bypass pipeline is communicated with an outlet of the low-pressure heating part; wherein the booster pump is provided with a rotating speed sensor, and the rotating speed sensor is electrically connected with the first electromagnetic valve and the second electromagnetic valve. According to the technical scheme, the problem that under the condition that the booster pump breaks down, condensate water in the pipeline stops flowing, and consequently the warm air pipeline is frozen can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of boiler warm air, in particular to an anti-freezing system for a warm air heater pipeline and a warm air heater system. Background Technique

[0002] The boiler warm air heater in a thermal power plant is mainly used to increase the inlet air temperature of the air preheater to prevent low-temperature corrosion and ash accumulation problems. By using the low-pressure extraction steam of the steam turbine as the heat source, the boiler warm air heater can heat the air entering the air preheater, thereby increasing the wall temperature of the air preheater and reducing the corrosion risk. In addition, it can also partially recover the waste heat of the flue gas and improve the thermal efficiency of the entire power plant. In winter, the boiler warm air heater is used as a warm air heater, and in summer, it can deeply recover the waste heat of the flue gas to achieve the annual energy-saving and environmental protection goals. In winter, when the booster pump of the warm air heater fails and trips, the condensate inside the warm air heater stops flowing. In the cold winter weather, the condensate pipeline of the warm air heater will quickly freeze (it will freeze within 15 minutes when the air supply temperature is -5°C). This will not only cause damage to the pipeline and the warm air heater equipment, but also cause low-temperature corrosion of the air preheater due to the low air supply temperature in winter, affecting the safe and stable operation of the system.

[0003] At present, there are two common anti-freezing measures in thermal power plants to prevent the failure and tripping of the booster pump of the warm air heater: 1. Increase the standby pump of the booster pump of the warm air heater. When the booster pump of the warm air heater fails and stops operating, the standby pump is started in time. The disadvantage of this method is that it increases the equipment investment cost. The cost of a single standby pump and its related materials is about 500,000 yuan. 2. When the booster pump of the warm air heater fails, the operator quickly isolates the entire warm air heater system and drains the internal condensate to prevent freezing. This method requires the operator to discover the failure in the first time, and at the same time, the operation is complex and has certain requirements for the operator's skill level. Summary of the Utility Model

[0004] The main purpose of the utility model is to propose an anti-freezing system for a warm air heater pipeline and a warm air heater system, aiming to solve the problem that when the booster pump fails, the condensate inside the pipeline stops flowing and causes the warm air pipeline to freeze.

[0005] To achieve the above purpose, an anti-freezing system for a warm air heater pipeline proposed by the utility model includes: a main pipeline, on which a booster pump, a first electromagnetic valve, a second electromagnetic valve, and a low-pressure heating part are sequentially arranged; and a bypass pipeline, which is communicated with the main pipeline. The connection point between the bypass pipeline and the main pipeline is located between the first electromagnetic valve and the second electromagnetic valve. A first valve is arranged at one end of the bypass pipeline close to the main pipeline, and the other end of the bypass pipeline far from the main pipeline is communicated with the outlet of the low-pressure heating part; wherein, a rotational speed sensor is arranged on the booster pump, and the rotational speed sensor is electrically connected to the first electromagnetic valve and the second electromagnetic valve.

[0006] In one embodiment, an alarm is provided on the main pipeline. The alarm is electrically connected to the rotational speed sensor, and the alarm is located at the outlet of the booster pump.

[0007] In one embodiment, a temperature sensor and a wireless transceiver are provided on the main pipeline. The wireless transceiver is located at one end of the main pipeline close to the bypass pipeline. The temperature sensor is electrically connected to the wireless transceiver and the rotational speed sensor, and the sensing end of the temperature sensor is located inside the main pipeline.

[0008] In one embodiment, a flowmeter is provided in the warm air heater pipeline anti-freezing system. The flowmeter is electrically connected to the alarm and the wireless transceiver, and the flowmeter is located between the booster pump and the first solenoid valve.

[0009] In one embodiment, the first solenoid valve is a proportional solenoid valve, and the proportional solenoid valve is electrically connected to the flowmeter.

[0010] In one embodiment, a polyurethane foam layer is sleeved on the outer walls of the main pipeline and the bypass pipeline.

[0011] In one embodiment, glass wool is sleeved on the outer walls of the main pipeline and the bypass pipeline, and the glass wool is located inside the polyurethane foam layer.

[0012] In one embodiment, a maintenance valve is provided on the booster pump, and the maintenance valve is located between the return water inlet of the main pipeline and the booster pump.

[0013] In one embodiment, the booster pump further includes a base, the base is located at the inlet of the main pipeline, and the booster pump is detachably connected to the base.

[0014] The present utility model also proposes a warm air heater system, which includes: a warm air heater pipeline anti-freezing system; and a heat exchange part, and the heat exchange part is located at the outlet of the low-pressure heating part.

[0015] The technical solution of the present utility model is to set a first solenoid valve and a second solenoid valve on the main pipe of the air heater, and set a rotational speed sensor on the booster pump. The rotational speed sensor is electrically connected to the first solenoid valve and the second solenoid valve. A bypass pipe communicating with the main pipe is arranged between the first solenoid valve and the second solenoid valve, and a first valve is arranged at one end of the bypass pipe close to the main pipe. When the booster pump fails during long-term use, the rotational speed sensor transmits a fault signal to the first solenoid valve and the second solenoid valve at the first time. After receiving the fault signal, the first solenoid valve and the second solenoid valve close, and the condensate in the main pipe stays between the first solenoid valve and the second solenoid valve. Due to the design of the bypass pipe between the first solenoid valve and the second solenoid valve, and the water pressure in the main pipe being higher than the water pressure at the outlet, the operator only needs to open the first valve on the bypass pipe to discharge the condensate inside the pipe through the bypass pipe to the outlet of the low-pressure heating part, thereby solving the problem of freezing of the air heater pipe. Brief Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0017] Figure 1 It is a schematic structural diagram of an embodiment of an anti-freezing system for an air heater pipe provided by the present utility model;

[0018] Figure 2 It is an enlarged view of an anti-freezing system for an air heater pipe provided by the present utility model at A.

[0019] Explanation of the reference numerals in the drawings:

[0020] 100, anti-freezing mechanism for air heater pipe; 1, main pipe; 11, booster pump; 111, rotational speed sensor; 112, maintenance valve; 113, base; 12, first solenoid valve; 13, second solenoid valve; 14, alarm; 15, temperature sensor; 16, wireless transceiver; 17, flowmeter; 18, polyurethane foam layer; 181, glass wool; 2, bypass pipe; 21, first valve.

[0021] The realization, functional characteristics and advantages of the purpose of the present utility model will be further described in conjunction with the embodiments with reference to the drawings. Detailed Embodiment

[0022] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0023] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0024] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0025] The present utility model provides a freeze protection system for a warm air heater pipeline.

[0026] Please refer to Figures 1 to 2 , in an embodiment of the present utility model, the freeze protection system for the warm air heater pipeline includes: a main pipeline and a bypass pipeline. A booster pump, a first solenoid valve, a second solenoid valve, and a low-pressure heating part are sequentially arranged on the main pipeline; the bypass pipeline is communicated with the main pipeline, and the connection point between the bypass pipeline and the main pipeline is located between the first solenoid valve and the second solenoid valve. A first valve is arranged at one end of the bypass pipeline close to the main pipeline, and the other end of the bypass pipeline far from the main pipeline is communicated with the outlet of the low-pressure heating part; wherein, the booster pump is provided with a rotational speed sensor, and the rotational speed sensor is electrically connected to the first solenoid valve and the second solenoid valve.

[0027] In an embodiment of the present utility model, the main pipeline is the total pipeline of the entire antifreeze system of the air preheater pipeline. All the return water from the boiler air preheater enters the main pipeline through the inlet of the main pipeline. The main pipeline is generally made of stainless steel or hot-dip galvanized steel pipe. Stainless steel pipes have the characteristics of high efficiency, vibration resistance, scale resistance, and corrosion resistance. These characteristics make stainless steel widely used in heat exchangers. Stainless steel heat exchange pipes can solve the contradiction between reducing the wall thickness to enhance the heat exchange effect and increasing the stiffness, achieving the perfect unity of the three. Hot-dip galvanized steel pipes are cost-effective, easy to process, and have good corrosion resistance. They are economical and practical in some applications that have certain requirements for corrosion resistance and service life but do not need to withstand extreme conditions.

[0028] The booster pump provides pressure for the return water section of the entire air preheater system. By using the booster pump, the pressure can be increased to ensure the smooth flow of the return water, improve the overall thermal efficiency and regulation ability of the system. The booster pump also has the advantages of simple structure, small volume, light weight, and convenient maintenance. It usually adopts the centrifugal pump principle, has a wide performance range and high rotational speed, and can be directly connected to an electric motor or a steam turbine to achieve a simple and compact transmission mechanism.

[0029] The first solenoid valve and the second solenoid valve are generally direct-acting solenoid valves or proportional solenoid valves. The direct-acting solenoid valve can work normally in an environment of vacuum, negative pressure, or zero pressure difference. Due to its working principle, the direct-acting solenoid valve has a very fast response speed and short action time, and is suitable for applications with a high opening and closing frequency. The structure of the direct-acting solenoid valve is relatively simple, which helps to improve its reliability and reduce maintenance requirements. The direct-acting solenoid valve usually has high reliability and can operate stably under various working conditions. The proportional solenoid valve controls the opening of the valve by adjusting the current in the electromagnetic coil, so as to achieve precise control of the fluid flow rate or pressure. The proportional solenoid valve can continuously adjust the opening of the valve according to the change of the input signal to adapt to different control requirements, and has the characteristics of precise control, fast response, good stability, and energy saving. The first solenoid valve and the second solenoid valve are connected to the main pipeline in sequence, and the flow rate and on-off of the return water in the main pipeline can be controlled by the opening and closing of the corresponding valves.

[0030] The low-pressure heating part is located after the second solenoid valve on the main pipeline. Since the boosting range of the booster pump is limited, a low-pressure area will be formed at the end far from the booster pump. The low-pressure heating part includes multiple low-pressure heaters. Before entering a system with higher pressure or temperature, the low-pressure heaters can be used to preheat the medium. By preheating the medium, the load of the main heating equipment can be reduced, thereby improving the energy efficiency of the entire system. The low-pressure heaters can precisely control the temperature of the medium, be used to adjust the temperature of the medium to meet the process requirements, and can be used as a safety protection measure to prevent the main heating equipment from overloading or overheating.

[0031] The bypass pipeline is the foundation of the entire anti-freezing system for the air preheater pipeline. The connection between the bypass pipeline and the main pipeline is located between the first solenoid valve and the second solenoid valve. One end of the bypass pipeline close to the main pipeline is provided with a first valve. The other end of the bypass pipeline far from the main pipeline is connected to the outlet of the low-pressure heating part. The first valve of the bypass pipeline is in a closed state during the normal operation of the air preheater system. When it is necessary to prevent freezing of the accumulated condensate or return water in the main pipeline, the bypass pipeline needs to be opened so that the condensate or return water inside the main pipeline flows out through the bypass pipeline to the outlet end of the low-pressure heating part, preventing the problem of freezing of the condensate or return water due to too low ambient temperature. The bypass pipeline is generally made of stainless steel or hot-dip galvanized steel pipe. The stainless steel pipe has the characteristics of high efficiency, vibration resistance, anti-scaling, and corrosion resistance. These characteristics make stainless steel widely used in heat exchangers. The stainless steel heat exchange pipe can solve the contradiction between reducing the wall thickness to enhance the heat exchange effect and increasing the stiffness, achieving the perfect unity of the three. The hot-dip galvanized steel pipe is cost-effective, easy to process, and has good corrosion resistance. It is economical and practical in some applications that have certain requirements for corrosion resistance and service life but do not need to withstand extreme conditions.

[0032] The booster pump is equipped with a rotational speed sensor. The rotational speed sensor is electrically connected to the first solenoid valve and the second solenoid valve. The rotational speed sensor is used to monitor the rotational speed of the booster pump. During the use of the air preheater system, when the booster pump fails, the rotational speed sensor immediately transmits the abnormal rotational speed signal to the processor. The processor converts the abnormal rotational speed signal into an electrical signal and transmits it to the first solenoid valve and the second solenoid valve that are electrically connected to the rotational speed sensor. After receiving the signal from the processor, the first solenoid valve and the second solenoid valve realize the function of automatically closing the valve.

[0033] In this embodiment, by setting the first solenoid valve and the second solenoid valve on the main pipeline of the air preheater, and setting a rotational speed sensor on the booster pump, electrically connecting the rotational speed sensor to the first solenoid valve and the second solenoid valve, and setting a bypass pipeline communicating with the main pipeline between the first solenoid valve and the second solenoid valve, and setting a first valve at one end of the bypass pipeline close to the main pipeline; when the booster pump fails during long-term use, the rotational speed sensor immediately transmits the fault signal to the processor. The processor converts the abnormal rotational speed signal into an electrical signal and transmits it to the first solenoid valve and the second solenoid valve that are electrically connected to the rotational speed sensor. After receiving the signal from the processor, the first solenoid valve and the second solenoid valve realize the function of automatically closing the valve. The condensate inside the main pipeline stays between the first solenoid valve and the second solenoid valve. Due to the design of the bypass pipeline between the first solenoid valve and the second solenoid valve, and the water pressure inside the main pipeline being higher than the water pressure at the outlet, the operator only needs to open the first valve on the bypass pipeline to make the condensate inside the pipeline flow out through the bypass pipeline to the outlet of the low-pressure heating part, thus solving the problem of freezing of the air preheater pipeline.

[0034] In the embodiment of the present utility model, asFigure 2 As shown, the main pipeline is equipped with an alarm, which is electrically connected to the rotational speed sensor, and the alarm is located at the outlet of the booster pump.

[0035] In one embodiment, the electrical connection between the alarm and the rotational speed sensor is generally used to monitor and control the rotational speed in the system. When the rotational speed is lower than the preset safety threshold or exceeds the preset safety threshold, the rotational speed sensor will detect this change and trigger the alarm to emit a warning sound or light signal through the electrical connection, reminding the operator to pay attention and check whether the booster pump is faulty and the backwater flow condition of the main pipeline. When the rotational speed is lower than the preset safety threshold, the booster pump fails, the backwater flow speed in the main pipeline decreases or stops, and the first solenoid valve and the second solenoid valve will close the valve after receiving the fault signal. The operator needs to open the first valve on the bypass pipeline to make the backwater between the first solenoid valve and the second solenoid valve flow into the outlet of the low-pressure heating part through the bypass pipeline.

[0036] In the embodiment of the present utility model, as Figure 1 and Figure 2 shown, the main pipeline is equipped with a temperature sensor and a wireless transceiver. The wireless transceiver is located at one end of the main pipeline close to the bypass pipeline. The temperature sensor is electrically connected to the wireless transceiver and the rotational speed sensor, and the sensing end of the temperature sensor is located inside the main pipeline.

[0037] In one embodiment, the electrical connection between the temperature sensor, the wireless transceiver, and the rotational speed sensor constitutes a comprehensive monitoring system that can collect and transmit key operating parameters such as the temperature inside the main pipeline and the temperature of the booster pump in real time. The temperature sensor is responsible for monitoring the temperature of the backwater in the main pipeline, the rotational speed sensor monitors the rotational speed of the booster pump, and the wireless transceiver serves as a bridge for data transmission, collecting and sending this data to the DCS (Distributed Control System) module through the wireless transceiver. The advantage of this configuration is that it provides a flexible solution without complex wiring, allowing the operator to remotely monitor the device status, respond promptly to temperature anomalies or rotational speed changes, thereby ensuring the safe operation of the system and optimizing the production process. Through this integrated monitoring method, enterprises can achieve more intelligent and automated control, improve efficiency, reduce energy consumption, and enhance the adaptability to the production environment.

[0038] In the embodiment of the present utility model, as Figure 2 shown, the antifreeze system for the warm air heater pipeline is equipped with a flow meter, which is electrically connected to the alarm and the wireless transceiver, and the flow meter is located between the booster pump and the first solenoid valve.

[0039] In another embodiment, the flowmeter is responsible for real-time monitoring of the medium flow rate in the pipeline. Once the detected flow rate drops to a level that may cause freezing, it will trigger an alarm to issue a warning, reminding the operator to take necessary measures. At the same time, the data of the flowmeter is transmitted to the DCS module through a wireless transceiver, enabling the management personnel to timely understand the operating status of the pipeline and quickly respond even when far away from the site. This intelligent configuration not only improves the anti-freezing ability of the system, ensures the safe operation of the warm air heater pipeline in a low-temperature environment, but also reduces the wiring requirements through wireless technology, lowers the maintenance cost, and enhances the reliability and flexibility of the system.

[0040] In an embodiment of the present utility model, as Figure 1 shown, the first solenoid valve is a proportional solenoid valve, and the proportional solenoid valve is electrically connected to the flowmeter.

[0041] In an embodiment, the first solenoid valve is set as a proportional solenoid valve, and the first solenoid valve is electrically connected to the flowmeter. In the warm air heater system, the first solenoid valve is integrated with the flowmeter through electrical connection, forming an accurate flow control system. This configuration allows the system to dynamically adjust the opening degree of the solenoid valve according to the actual flow demand, achieving precise control of the medium flow rate. The flowmeter provides real-time flow data, and the proportional solenoid valve adjusts its working state according to these data to ensure that the warm air heater system can maintain the best flow and pressure levels under various working conditions. This intelligent adjustment mechanism not only improves the energy efficiency and response speed of the system, but also enhances the stability and safety of the system, providing a strong guarantee for the efficient operation of the warm air heater.

[0042] In an embodiment of the present utility model, as Figure 2 shown, a polyurethane foam layer is sleeved on the outer walls of the main pipeline and the bypass pipeline.

[0043] In an embodiment, a polyurethane foam layer is sleeved on the outer walls of the main pipeline and the bypass pipeline. This design provides efficient heat insulation effect, significantly reducing the heat loss of the pipeline during the transportation of hot medium. Polyurethane foam, as an excellent thermal insulation material, has low thermal conductivity and good mechanical properties, which can persistently maintain the temperature of the medium inside the pipeline and prevent the influence of the external environment on the temperature of the medium inside the pipeline. This heat insulation measure not only improves the energy utilization efficiency, reduces the operating cost, but also helps to reduce the thermal impact of heat loss on the surrounding environment, enhancing the environmental performance of the system. In addition, the polyurethane foam layer also has the functions of sound insulation and corrosion prevention, providing additional protection for the pipeline and extending the service life of the warm air heater system.

[0044] In an embodiment of the present utility model, as Figure 2 shown, glass wool is sleeved on the outer walls of the main pipeline and the bypass pipeline, and the glass wool is located inside the polyurethane foam layer.

[0045] In another embodiment, the outer walls of the main pipeline and the bypass pipeline adopt a double-layer heat insulation structure, where the glass wool quilt is arranged inside the polyurethane foam layer. This composite heat insulation design makes full use of the advantages of the two materials: the polyurethane foam layer provides excellent heat insulation performance due to its closed-cell structure, while the inner glass wool enhances the heat insulation effect due to its high porosity and low thermal conductivity. At the same time, the glass wool also has good sound absorption performance, which helps to reduce the noise generated during the operation of the system. This structure not only effectively reduces heat loss, improves energy use efficiency, but also extends the service life of the pipeline by enhancing the mechanical strength and durability of the heat insulation layer, ensuring that the air heater system can operate stably and efficiently in various environments.

[0046] In an embodiment of the present utility model, as Figure 1 shown, the booster pump is provided with a maintenance valve, and the maintenance valve is located between the return water inlet of the main pipeline and the booster pump.

[0047] In another embodiment, a maintenance valve is installed on the booster pump, and the maintenance valve is located between the return water inlet of the main pipeline and the booster pump. This layout provides an easily operable maintenance point for the system, enabling quick and convenient maintenance and inspection of the booster pump when needed without interrupting the operation of the entire system. The presence of the maintenance valve not only improves the maintainability of the system but also ensures rapid isolation in case of a booster pump failure, thereby reducing repair time and minimizing the impact on system operation. In addition, the maintenance valve helps to quickly cut off the water flow in case of an emergency, ensuring the safety of the system and the operators.

[0048] In an embodiment of the present utility model, as Figure 2 shown, the booster pump further includes a base, and the base is located at the inlet of the main pipeline. The booster pump is detachably connected to the base.

[0049] In this embodiment, the booster pump and the base are detachably connected by bolts or buckles and other detachable connection methods. This design provides great flexibility and convenience. The detachable connection means that the booster pump can be quickly installed or removed without disturbing the main pipeline, greatly simplifying the maintenance, repair or replacement process of the pump. In addition, the base provides a stable support for the booster pump, ensuring the stability and reliability of the pump during operation. This design not only improves the efficiency of maintenance work, reduces the complexity and cost of system maintenance, but also enhances the safety and durability of the entire anti-freezing system of the air heater pipeline.

[0050] The present utility model also provides a warm air heater system, which includes a warm air heater pipeline anti-freezing system and a heat exchange part. The heat exchange part is located at the outlet of the low-pressure heating part. The specific structure of this warm air heater system refers to the above-mentioned embodiments. Since this warm air heater system adopts all the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one.

[0051] The above is only an exemplary embodiment of the present utility model, and does not limit the patent scope of the present utility model. Any equivalent structural transformation made under the technical concept of the present utility model by using the content of the specification and drawings of the present utility model, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present utility model.

Claims

1. A pipe anti-freezing system (100) for a warm air heater, characterized in that, The anti-freezing system (100) for the warm air heater pipeline includes: A main pipeline (1), on which a booster pump (11), a first solenoid valve (12), a second solenoid valve (13) and a low-pressure heating part are successively arranged; and, A bypass pipeline (2), which is communicated with the main pipeline. The connection part of the bypass pipeline (2) and the main pipeline (1) is located between the first solenoid valve (12) and the second solenoid valve (13). A first valve (21) is arranged at one end of the bypass pipeline (2) close to the main pipeline (1), and the other end of the bypass pipeline (2) far from the main pipeline (1) is communicated with the outlet of the low-pressure heating part; Wherein, the booster pump (11) is provided with a rotational speed sensor (111), and the rotational speed sensor (111) is electrically connected to the first solenoid valve (12) and the second solenoid valve (13).

2. The warm air heater pipe anti-freezing system (100) according to claim 1, characterized in that, An alarm (14) is arranged on the main pipeline (1), and the alarm (14) is electrically connected to the rotational speed sensor (111). The alarm (14) is located at the outlet of the booster pump (11).

3. The anti-freezing system (100) for the warm air heater pipeline according to claim 2, wherein, A temperature sensor (15) and a wireless transceiver (16) are arranged on the main pipeline (1). The wireless transceiver (16) is located at one end of the main pipeline (1) close to the bypass pipeline (2). The temperature sensor (15) is electrically connected to the wireless transceiver (16) and the rotational speed sensor (111). The sensing end of the temperature sensor (15) is located inside the main pipeline (1).

4. The warm air heater pipe anti-freezing system (100) according to claim 2, wherein, A flowmeter (17) is arranged on the main pipeline (1), and the flowmeter (17) is electrically connected to the alarm (14) and the wireless transceiver (16). The flowmeter (17) is located between the booster pump (11) and the first solenoid valve (12).

5. The warm air heater pipe anti-freezing system (100) according to claim 4, characterized in that, The first solenoid valve (12) is a proportional solenoid valve, and the proportional solenoid valve is electrically connected to the flowmeter (17).

6. The heater pipe anti-freezing system (100) according to claim 1, characterized in that, A polyurethane foam layer (19) is sleeved on the outer walls of the main pipeline (1) and the bypass pipeline (2).

7. The anti-freezing system (100) for the warm air heater pipeline according to claim 6, characterized in that, A glass wool (191) is sleeved on the outer walls of the main pipeline (1) and the bypass pipeline (2). The glass wool (191) is located inside the polyurethane foam layer (19).

8. The anti-freezing system (100) for the warm air heater pipeline according to claim 1, wherein, The booster pump (11) is provided with a maintenance valve (112), and the maintenance valve (112) is located between the return water inlet of the main pipeline (1) and the booster pump (11).

9. The anti-freezing system (100) for the warm air heater pipeline according to claim 1, characterized in that, The booster pump (11) further includes a base (113), and the base (113) is located at the inlet of the main pipeline (1). The booster pump (11) is detachably connected to the base (113).

10. A warm air heater system, characterized in that, The warm air heater system includes: The anti-freezing system (100) for the warm air heater pipeline according to any one of claims 1 to 9; and, A heat exchange part, which is located at the outlet of the low-pressure heating part.

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