Ring main unit circulating water cooling system

Abstract

The utility model discloses a circulating water cooling system of a ring main unit, comprising a three-phase power supply which comprises three-phase power lines L1, L2 and L3 and a zero line N; the three-phase power supply is connected with a circuit breaker QF; the circuit breaker QF is connected with a main circuit and a control circuit; wherein the main circuit comprises a motor M1 which is connected with a thermal relay FR and contactors KM1 and KM2; the control circuit comprises a water circulation control loop and a fire extinguishing alarm loop; the water circulation control loop is used for controlling water to periodically flow forward and backward in a ring main unit pipeline; and the fire extinguishing alarm loop is used for starting a fire extinguishing function and giving an alarm when the temperature exceeds a set threshold value. The utility model has the following beneficial effects: the system can realize uniform cooling of the ring main unit through forward and reverse two-way circulation flow of water in the pipeline, and can automatically start a fire extinguishing function and give an alarm when a fire disaster occurs, thereby improving the operation safety and stability of the ring main unit.

Description

Technical Field

[0001] The utility model relates to the field of heat dissipation and safety protection of electric power equipment, in particular to a circulating water cooling system for a ring network cabinet. Background Art

[0002] Ring main units (RMUs) are crucial equipment in urban power distribution networks. They primarily provide ring network power supply for medium-voltage power grids and undertake the segmentation, interconnection, control, and protection functions of the distribution network. Because RMUs contain a variety of switchgear and control components, such as circuit breakers and disconnectors, they generate significant heat during long-term operation. Especially under high load, internal temperatures can rise significantly, impacting the normal operation and service life of the equipment and, in severe cases, potentially causing fires and other safety hazards.

[0003] Currently, the temperature control and heat dissipation of ring main units mainly adopt the following methods: passive heat dissipation, which enhances the natural heat dissipation capacity by setting up heat dissipation holes, heat sinks and other structures; forced air cooling, which uses fans to force ventilation and cool down; and simple water cooling systems, which carry heat through unidirectional water flow in pipes. These traditional methods have the following disadvantages:

[0004] Passive cooling has low cooling efficiency and cannot meet the cooling requirements during high-load operation.

[0005] Although forced air cooling can improve heat dissipation efficiency, the fan is prone to dust accumulation, is noisy, and has low operational reliability;

[0006] Traditional one-way water cooling systems are prone to forming uneven temperature areas in the pipeline, resulting in inconsistent cooling effects;

[0007] Existing cooling systems lack active fire protection. Once excessive temperatures cause a fire, external fire extinguishing equipment is often required.

[0008] Most ring main unit cooling systems lack automatic alarm functions and are unable to promptly notify staff when abnormal situations occur.

[0009] With the increasing load on urban power grids and the increasing demand for power supply reliability, the safe and stable operation of ring main units (RMUs), as key power distribution equipment, has become increasingly important. Therefore, developing a circulating water cooling system for RMUs that can achieve efficient heat dissipation, bidirectional circulation, automatic fire extinguishing, and alarm functions is of great practical significance. Utility Model Content

[0010] The purpose of the utility model is to provide a circulating water cooling system for a ring network cabinet, which can achieve uniform cooling of the ring network cabinet through the forward and reverse bidirectional circulation flow of water in the pipeline, and automatically activate the fire extinguishing function and sound an alarm when a fire occurs, thereby improving the operating safety and stability of the ring network cabinet.

[0011] The above technical objectives of the present invention are achieved through the following technical solutions:

[0012] A circulating water cooling system for a ring main unit (RMU), comprising: a three-phase power supply, the three-phase power supply comprising three-phase power lines L1, L2, and L3 and a neutral line N; the three-phase power supply being connected to a circuit breaker QF; the circuit breaker QF being connected to a main circuit and a control circuit; wherein the main circuit comprises a motor M1, which is connected to a thermal relay FR and contactors KM1 and KM2; the control circuit comprising a water circulation control loop and a fire extinguishing alarm loop; the water circulation control loop being used to control the periodic forward and reverse flow of water in the RMU pipeline; and the fire extinguishing alarm loop being used to activate a fire extinguishing function and sound an alarm when the temperature exceeds a set threshold.

[0013] The utility model is further configured as follows: the water circulation control circuit includes: a stop button SB1, a temperature switch T1, time relays KT1 and KT2, relays KM1 and KM2; the temperature switch T1 is connected to the time relays KT1 and KT2; the relays KM1 and KM2 respectively control the contactors KM1 and KM2 to realize the forward and reverse rotation of the motor M1.

[0014] The present invention is further configured as follows: the temperature threshold of the temperature switch T1 is set to 50°C. When the internal temperature of the ring network cabinet exceeds 50°C, the temperature switch T1 triggers the water circulation control loop to start.

[0015] The utility model is further configured as follows: the time relay KT1 is set to delay action for 55 seconds after power is turned on, and the time relay KT2 is set to delay action for 55 seconds after power is turned on; the time relay KT1 is connected to the relay KM1, and the time relay KT2 is connected to the relay KM2, and the two alternately control the forward and reverse rotation of the motor M1.

[0016] The utility model is further configured as follows: the fire extinguishing alarm circuit includes: a temperature switch T2, a solenoid valve EV and an alarm H; the temperature switch T2 is electrically connected to the solenoid valve EV and the alarm H.

[0017] The present invention is further configured as follows: the temperature threshold of the temperature switch T2 is set to 150° C. When the internal temperature of the ring network cabinet exceeds 150° C., the temperature switch T2 triggers the solenoid valve EV to open and the alarm H to sound an alarm.

[0018] The present invention is further configured as follows: the thermal relay FR is arranged in the power supply circuit of the motor M1, and is used to cut off the power supply when the motor is overloaded, so as to protect the safety of the motor.

[0019] The utility model is further configured as follows: the solenoid valve EV is provided with a water inlet X1 and a water outlet X2. When the solenoid valve EV receives a trigger signal from the temperature switch T2, it opens the valve to introduce water into the ring network cabinet for fire extinguishing.

[0020] In summary, the present invention has the following beneficial effects:

[0021] Bidirectional circulation water cooling design: Through the coordinated control of time relays KT1, KT2 and relays KM1, KM2, water can flow periodically in the RMU pipeline in forward and reverse directions, avoiding the "hot spot" problem that is prone to occur in traditional unidirectional water cooling systems. It makes the temperature distribution of various parts of the RMU more uniform, greatly improving the heat dissipation efficiency and cooling effect.

[0022] Temperature threshold automatic start function: The system sets a temperature start threshold of 50°C. When the internal temperature of the ring network cabinet exceeds this threshold, the water circulation cooling system is automatically started without manual intervention, reducing human monitoring costs and improving the system's automation level and response speed.

[0023] Integrated design of automatic fire extinguishing and early warning: The system innovatively integrates temperature monitoring, automatic fire extinguishing and alarm functions. When the temperature exceeds 150°C, it not only automatically opens the solenoid valve to spray water into the ring main unit to extinguish the fire, but also activates the alarm to sound the alarm, realizing the integrated protection of "early warning-fire extinguishing-alarm", greatly improving the safety of the ring main unit.

[0024] Motor protection mechanism: The thermal relay FR is used to protect the water pump motor from overload, preventing the motor from being damaged due to long-term operation or abnormal conditions, thereby extending the service life of the system and reducing maintenance costs.

[0025] Periodic forward and reverse rotation design: The forward and reverse rotation control with a cycle of 55 seconds not only avoids the pipeline deposition problem caused by long-term unidirectional flow, but also reduces the impact of frequent start and stop of the motor on the system through a longer switching cycle, taking into account the heat dissipation effect and system stability.

[0026] Compared with existing technologies, this system realizes the dual functions of conventional heat dissipation and emergency fire extinguishing, solving the problems of single function, uneven heat dissipation, and lack of active fire protection of traditional ring network cabinet heat dissipation system, and significantly improving the operating safety, reliability and service life of the ring network cabinet. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the circuit principle diagram of the circulating water cooling system of the ring network cabinet of this utility model. DETAILED DESCRIPTION

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "page", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0030] In the description of this utility model, "plurality" means two or more, unless otherwise clearly defined. In this utility model, unless otherwise clearly defined and defined, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or it can be internal communication between two components. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to the specific circumstances.

[0031] The present invention will be described in further detail below with reference to the accompanying drawings.

[0032] like Figure 1 As shown, the utility model provides a circulating water cooling system for a ring main unit, which mainly includes three parts: a power input part, a main circuit and a control circuit.

[0033] The power input section includes three-phase power lines L1, L2, and L3 and a neutral line N, which are connected to the system through a circuit breaker QF to provide power to the entire system. Circuit breaker QF acts as a master switch and short-circuit protection, ensuring safe power use in the system.

[0034] The main circuit primarily includes a water pump motor M1, which drives the water pump in the water circulation system, circulating water through the ring main unit pipes. A thermal relay FR is also included in the main circuit, connected in series with motor M1. This relay monitors the motor's operating current and automatically disconnects the circuit when motor M1 overloads, protecting the motor from damage. Contactors KM1 and KM2 control the forward and reverse rotation of motor M1, respectively, enabling bidirectional water circulation in the pipes.

[0035] The control circuit is divided into two main functional loops: water circulation control loop and fire extinguishing alarm loop.

[0036] The water circulation control circuit includes a stop button SB1, a temperature switch T1, time relays KT1 and KT2, and relays KM1 and KM2. The temperature switch T1 is set to a threshold of 50°C. When the temperature inside the ring main unit exceeds 50°C, the switch closes, activating the water circulation control system. Time relays KT1 and KT2 are each set to a 55-second delay after power is applied and are connected to relays KM1 and KM2. Relays KM1 and KM2 control the closing and opening of contactors KM1 and KM2, respectively, to achieve forward and reverse rotation of motor M1, thereby periodically circulating water in the ring main unit pipelines in both forward and reverse directions. The stop button SB1 is used to manually shut off the system power when necessary.

[0037] The fire alarm circuit includes a temperature switch T2, a solenoid valve EV, and an alarm H. The temperature switch T2 is set to a threshold of 150°C. When the internal temperature of the RMU exceeds 150°C, it indicates a possible fire. The temperature switch T2 closes, triggering the opening of the solenoid valve EV and the sounding of the alarm H. Once the solenoid valve EV opens, water enters the RMU, extinguishing the fire. The alarm signal from the alarm H alerts personnel to the abnormally high temperature in the RMU, requiring emergency attention.

[0038] Here's how it works:

[0039] Normal heat dissipation working state: When the internal temperature of the ring main unit is lower than 50℃, the temperature switch T1 remains in the open state and the water circulation system does not work. When the temperature rises above 50℃, the temperature switch T1 closes and the time relays KT1 and KT2 start working.

[0040] Circulating water cooling: After time relay KT1 is energized, after a 55-second delay, its normally open contacts close, energizing relay KM1 and contactor KM1, controlling motor M1 to rotate forward, causing water to flow in the RMU pipeline. After 55 seconds, contact KT1 corresponding to time relay KT1 opens, de-energizing relay KM1 and disconnecting contactor KM1. Simultaneously, contacts KT1 of time relays KT2 and KM2 close, energizing contactor KM2, controlling motor M1 to rotate in the reverse direction, causing water to flow in the reverse direction. After 55 seconds, time relay KT2 expires, disconnecting contact KT2 connected to time relay KT1. This disconnects contact KT2, de-energizing time relay KT1, and resetting the system. This cycle repeats, achieving bidirectional water circulation in the pipelines and evenly cooling all parts of the RMU.

[0041] Overload protection: The thermal relay FR continuously monitors the operating current of motor M1. If the motor current exceeds the limit due to a fault or other reason, the thermal relay FR automatically disconnects the circuit and cuts off the power supply to the motor, preventing damage due to overload.

[0042] Emergency fire extinguishing: When the temperature inside the RMU rises abnormally above 150°C, the temperature switch T2 closes, the solenoid valve EV is energized and opens, allowing water to flow into the RMU to extinguish any fire. Simultaneously, the alarm H sounds an alarm signal, alerting personnel to take emergency action.

[0043] System stop: Press the stop button SB1 to cut off the control circuit power supply and the system stops working. In an emergency, the power supply of the entire system can also be cut off through the circuit breaker QF.

[0044] This new RMU circulating water cooling system achieves uniform cooling of the RMU through bidirectional water circulation in the pipes. It also automatically activates a fire extinguishing function and issues an alarm when the temperature rises abnormally. It features effective heat dissipation, high safety, and a high degree of automation. The system boasts a simple structure, reliable control, and is easy to install and maintain, making it suitable for temperature control and safety protection of various types of RMUs.

[0045] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A ring main unit circulating water cooling system, characterized in that: include: Three-phase power supply, the three-phase power supply includes three-phase power lines L1, L2, L3 and a neutral line N; the three-phase power supply is connected to a circuit breaker QF; the circuit breaker QF is connected to a main circuit and a control circuit; wherein, the main circuit includes a motor M1, connected to a thermal relay FR and contactors KM1 and KM2; the control circuit includes a water circulation control loop and a fire alarm loop; the water circulation control loop is used to control the periodic forward and reverse flow of water in the ring network cabinet pipeline; the fire alarm loop is used to activate the fire extinguishing function and issue an alarm when the temperature exceeds a set threshold.

2. The ring main unit circulating water cooling system according to claim 1, characterized in that: The water circulation control circuit includes: a stop button SB1, a temperature switch T1, time relays KT1 and KT2, and relays KM1 and KM2; the temperature switch T1 is connected to the time relays KT1 and KT2; the relays KM1 and KM2 control contactors KM1 and KM2 respectively to realize forward and reverse rotation of the motor M1.

3. The ring main unit circulating water cooling system according to claim 2, characterized in that: The temperature threshold of the temperature switch T1 is set to 50° C. When the internal temperature of the ring main unit exceeds 50° C., the temperature switch T1 triggers the water circulation control loop to start.

4. The ring main unit circulating water cooling system according to claim 2, characterized in that: The time relay KT1 is set to delay action for 55 seconds after power is turned on, and the time relay KT2 is set to delay action for 55 seconds after power is turned on; the time relay KT1 is connected to the relay KM1, and the time relay KT2 is connected to the relay KM2, and the two cyclically control the forward and reverse rotation of the motor M1.

5. The ring main unit circulating water cooling system according to claim 1, characterized in that: The fire extinguishing alarm circuit includes: a temperature switch T2, a solenoid valve EV and an alarm H; the temperature switch T2 is electrically connected to the solenoid valve EV and the alarm H.

6. The ring main unit circulating water cooling system according to claim 5, characterized in that: The temperature threshold of the temperature switch T2 is set to 150° C. When the internal temperature of the ring main unit exceeds 150° C., the temperature switch T2 triggers the solenoid valve EV to open and the alarm H to sound an alarm.

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