Electric automatic control system of heating circulating pump

Abstract

According to a main circuit, a three-phase 380V power supply is connected to a second air switch QF2 through a first 3P air switch QF1, and the lower side of the air switch QF2 is sequentially connected with a first frequency converter U1, a first alternating current contactor 1KM, a first thermal relay 1FR and a first alternating current motor M1; and the lower side of the third air switch QF3 is sequentially connected with a second frequency converter U2, a second alternating current contactor 2KM, a second thermal relay 2FR and a second load motor M2. According to the pressure requirement, the output frequency of the frequency converter is automatically changed, the water supply amount is continuously adjusted, the pressure tracking set value is met, the automation degree is high, automatic adjustment can be fully automatically conducted according to the pressure requirement value, the pipe network pressure is kept constant, and the pipe network burst risk possibly caused by too large pressure is avoided; the optimal operation efficiency of the water pump and stable operation of equipment are guaranteed, and manual intervention is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of electrical control of heating circulation pumps, in particular to an electrical automatic control system for a heating circulation pump. Background Art

[0002] The heating circulation pump is a key equipment in the heating system. The current common control method is to manually adjust the potentiometer to give a signal to change the frequency of the inverter or to adjust the inverter parameters on the panel to change the frequency and control the motor speed to adjust the circulation pressure. In addition, there is also industrial frequency soft start operation, which adjusts the pressure value by adjusting the valve opening. The disadvantages are that the operation is complicated and the error is large. The system lacks stability and untimely adjustments will cause the heat network to operate out of order. Utility Model Content

[0003] The utility model aims to solve the problems of manual control of heating circulation pump, complicated operation by personnel, large error, lack of system operation stability, and untimely adjustment causing heat network operation disorder. Thus, an electrical automatic control system for heating circulation pump is provided, which has a high degree of automation, can provide feedback of the current pressure value in the pipeline, can automatically adjust according to the pressure required by the user, and achieve precise control.

[0004] To achieve the above-mentioned purpose of the utility model, the utility model provides an electrical automatic control system for a heating circulation pump, including a three-phase power supply L1, L2, L3, a first AC motor M1, a second AC motor M2, a first 3P air switch QF1, a second 3P air switch QF2, a third 3P air switch QF3, a first 1P air switch QF4, a DC power supply, a first frequency converter U1, a first AC contactor 1KM, a first thermal relay 1FR, a second AC contactor 2KM, a second thermal relay 2FR, a switching switch SA, a first constant pressure water supply controller, a first switching switch SA1, an indicator light HG1, an indicator light HR1, and a first pressure sensor.

[0005] Main circuit: The three-phase 380V power supply is connected to the second air switch QF2 through the first 3P air switch QF1. The lower side of the air switch QF2 is connected to the first frequency converter U1, the first AC contactor 1KM, the first thermal relay 1FR, and the first AC motor M1 in sequence; the lower side of the third air switch QF3 is connected to the second frequency converter U2, the second AC contactor 2KM, the second thermal relay 2FR, and the second load motor M2 in sequence;

[0006] Control circuit: The first 1P air switch QF4 is respectively connected to the first conversion switch SA1, the normally open contact and the upper side of the normally closed contact of the first contactor 1KM, the lower side of the normally open contact of the first contactor 1KM is connected to the indicator light HG1, and the lower side of the normally closed contact of the contactor 1KM is connected to the indicator light HR1. The first conversion switch SA1 is connected to the first constant pressure water supply controller, and the G terminal of the first constant pressure water supply controller is connected to the 11 terminal of the first frequency converter, which is used to provide a negative voltage of 0-10V for the first frequency converter.

[0007] The D / A terminal of the first constant pressure water supply controller is connected to the first inverter 12 terminal, which is used to provide a 0-10V positive voltage to the first inverter to adjust the frequency of the first inverter. The CM terminal of the first constant pressure water supply controller is connected to the CM terminal of the first inverter. The FR terminal of the first constant pressure water supply controller is connected to the FWD terminal of the first inverter, which is used to provide an operation signal to the first inverter. The IN1 and IN2 terminals of the first constant pressure water supply controller are short-circuited and connected to the PIN2 terminal of the first pressure sensor. The PIN1 terminal of the first pressure sensor is connected to the 24V+ terminal of the DC power supply. The GND terminal of the high-pressure water supply controller is short-circuited and connected to the 24V-terminal of the DC power supply. The above connection is converted and output through the first pressure sensor to output an analog 4-20mA signal to the first constant-pressure water supply controller. The B1 terminal of the first constant-pressure water supply controller is connected to the upper end of the normally closed contact of the second AC contactor 2KM, and the lower end of the normally closed contact of the second AC contactor 2KM is connected to the AC contactor 1KM coil. The first AC contactor 1KM coil is connected to the normally closed contact of the first thermal relay 1FR, and the normally closed contact of the first thermal relay 1FR is connected to the N line, so that the first AC contactor 1KM coil is energized.

[0008] Furthermore, the main circuit and the control circuit are provided with two identical sets, one for use and one for backup.

[0009] The utility model heating circulation pump electrical automatic control system automatically changes the inverter output frequency according to the pressure demand, continuously adjusts the water supply, and meets the pressure tracking set value. It has a high degree of automation and can realize full automatic adjustment according to the pressure demand value setting, maintain the constant pressure of the pipe network, avoid the risk of pipe network burst due to excessive pressure, and operate with variable frequency to ensure the optimal operation efficiency of the water pump and the stable operation of the equipment, reducing manual intervention. In addition, the utility model is equipped with a dual power supply control system, one for use and one for backup. When a system fails or needs to be repaired during the daily maintenance cycle, it can be switched to another system with one key, which can effectively improve the stability of the heating system. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is the main circuit schematic diagram of the utility model of an electrical automatic control system for a heating circulation pump

[0011] Figure 2This is the control circuit schematic diagram of the utility model of an electrical automatic control system for a heating circulation pump DETAILED DESCRIPTION

[0012] In order to better understand the purpose, structure and function of the utility model, the following is a further detailed description of an electrical automatic control system for a heating circulation pump of the utility model in conjunction with the accompanying drawings.

[0013] The electrical automatic control system of the heating circulation pump uses the DHC-8000 series constant pressure water supply constant pressure water supply controller as the main control element. This element is powerful, compact, has strong anti-interference ability, and has PID parameter self-tuning. It can complete the measurement, conversion, reading and control of physical quantities such as temperature and pressure in conjunction with sensors, and when combined with a frequency converter, it can form a suitable microcomputer-controlled variable frequency speed regulation constant pressure water supply system. Fuji 5000P11 series frequency converters are used to control and protect the motor. The number of motor revolutions can be adjusted according to actual needs, thereby reducing energy consumption, improving efficiency, and protecting the motor from overload, overheating, undervoltage and other factors. Using a pressure sensor as a measuring element, this element can provide accurate pressure measurement results, has long-term stability, is easy to integrate into various control systems, and provides a convenient and fast configuration method.

[0014] Figure 1 This is the electrical schematic diagram of the main circuit of this electrical system. The following is an analysis of the schematic diagram.

[0015] The three-phase 380V power supply is connected to the upper sides of the conversion switch SA, the second 3P air switch QF2 and the third 3P air switch QF3 through the first 3P air switch QF1, and the lower side of the conversion switch SA is connected to the voltmeter PV; the lower side of the second 3P air switch QF2 is connected to the input terminal of the first inverter U1, the output terminal of the first inverter U1 is connected to the upper side of the first AC contactor 1KM, the lower side of the first AC contactor 1KM is connected to the upper side of the first thermal relay 1FR, the lower side of the first thermal relay 1FR is connected to the load first AC motor M1, and the first AC motor M1 is reliably grounded; the lower side of the third 3P air switch QF3 is connected to the input terminal of the second inverter U2, the output terminal of the second inverter U2 is connected to the upper side of the second AC contactor 2KM, the lower side of the second AC contactor 2KM is connected to the upper side of the second thermal relay 2FR, the lower side of the second thermal relay 2FR is connected to the load second AC motor M2, and the second AC motor M2 is reliably grounded; the ammeters PA1, PA2, and PA3 are respectively connected to the current transformers TAa~c.

[0016] Figure 2 This is the electrical schematic diagram of the control circuit of this electrical system. The following is an analysis of the schematic diagram.

[0017] The control circuit is provided with 220V AC power by L12 and N line. The power is connected to the first conversion switch SA1, the first contactor 1KM normally open contact and the upper side of the normally closed contact through the first 1P air switch QF4. The lower side of the first contactor 1KM normally open contact is connected to the indicator light HG1, and the lower side of the first contactor 1KM normally closed contact is connected to the indicator light HR1. When the first contactor 1KM is disconnected, HR1 lights up. When the first contactor 1KM is closed, the indicator light HG1 lights up. The first conversion switch SA1 rotates left, and the first constant pressure water supply controller is energized. The G terminal of the first constant pressure water supply controller is connected to The first constant pressure water supply controller is connected to the first inverter 11 terminal to provide a 0-10V negative voltage to the first inverter. The first constant pressure water supply controller D / A terminal is connected to the first inverter 12 terminal to provide a 0-10V positive voltage to the first inverter to adjust the frequency of the first inverter. The first constant pressure water supply controller CM terminal is connected to the first inverter CM terminal. The first constant pressure water supply controller FR terminal is connected to the first inverter FWD terminal to provide an operating signal to the first inverter. The first constant pressure water supply controller IN1 and IN2 terminals are short-circuited and connected to the first pressure sensor PIN2 terminal. The first pressure sensor The sensor PIN1 terminal is connected to the DC power supply 24V+ terminal, and the first constant pressure water supply controller GND terminal is short-circuited and connected to the DC power supply 24V- terminal. The above connection is converted and output through the first pressure sensor. The analog 4-20mA signal is given to the first constant pressure water supply controller. The first constant pressure water supply controller B1 terminal outputs an AC 220V live wire, which is connected to the upper end of the second AC contactor 2KM normally closed contact. The lower end of the second AC contactor 2KM normally closed contact is connected to the first AC contactor 1KM coil, in which the 2KM normally closed contact is connected in series, which acts as an interlock between 1KM and 2KM. Protection, when starting 2KM, 2KM normally closed contact is disconnected, 1KM coil is de-energized, the first AC contactor 1KM coil is connected to the first thermal relay 1FR normally closed contact, the first thermal relay 1FR normally closed contact is connected to the N line, 1FR is used as motor overload protection, when the motor main circuit is overloaded, the normally closed point is disconnected, the circuit loop zero line N is disconnected, and the first AC contactor 1KM coil is de-energized. Through the above connection, 220V AC is passed through the first AC contactor 1KM coil during operation, so that the first contactor 1KM main contact is closed to operate the first motor M1. The two-phase 220V power supply is connected to the DC power supply through QF6.

[0018] The power supply is connected to the first conversion switch SA1, the normally open contact and the upper side of the normally closed contact of the second contactor 2KM through QF5, the lower side of the normally open contact of the second contactor 2KM is connected to the indicator light HG2, and the lower side of the normally closed contact of the second contactor 2KM is connected to the indicator light HR2. When the second contactor 2KM is disconnected, HR2 lights up, and when the second contactor 2KM is closed, the indicator light HG2 lights up, the second conversion switch SA1 rotates right, the constant pressure water supply controller 2 is powered, and the first constant pressure water supply controller is powered off at the same time, and the G terminal of the second constant pressure water supply controller is connected to the terminal 11 of the second frequency converter. Provide 0-10V negative voltage for the second frequency converter, connect the D / A terminal of the second constant pressure water supply controller to the 12 terminal of the second frequency converter, provide 0-10V positive voltage for the frequency converter, adjust the frequency of the second frequency converter 2, connect the CM terminal of the second constant pressure water supply controller to the CM terminal of the second frequency converter, connect the FR terminal of the second constant pressure water supply controller to the FWD terminal of the second frequency converter, provide the operation signal for the second frequency converter, connect the IN1 and IN2 terminals of the second constant pressure water supply controller to the PIN2 terminal of the second pressure sensor by short connection, and connect the PIN1 terminal of the second pressure sensor to the PIN2 terminal of the second pressure sensor. The second constant pressure water supply controller is connected to the DC power supply 24V+ terminal, and the GND terminal of the second constant pressure water supply controller is short-circuited to the DC power supply 24V- terminal. The above connection is converted and output through the second pressure sensor. The analog 4-20mA signal is given to the second constant pressure water supply controller. The second constant pressure water supply controller B1 terminal outputs an AC 220V live wire, which is connected to the upper end of the normally closed contact of the first AC contactor 1KM. The lower end of the normally closed contact of the first AC contactor 1KM is connected to the second AC contactor 2KM coil, in which the 1KM normally closed contact is connected in series, which acts as an interlocking protection between 2KM and 1KM. Protection, when 1KM is started, the normally closed contact of 1KM is disconnected, so that the 2KM coil is de-energized, the AC contactor 2KM coil is connected to the normally closed contact of the thermal relay 2FR, and the normally closed contact of the second thermal relay 2FR is connected to the N line. 2FR is used as a motor overload protection. When the main circuit of the motor is overloaded, the normally closed point is disconnected, and the circuit loop neutral line N is disconnected to de-energize the second AC contactor 2KM coil. Through the above connection, 220V AC is passed through the second AC contactor 2KM coil during operation, so that the second contactor 2KM main contact is closed to operate the second motor M2.

[0019] The two control circuits are the same. Taking the first one as an example, the control circuit monitors the water pressure in the heating circulating water network in real time through the first pressure sensor installed in the heating circulating water pipeline. The first pressure sensor converts the monitored water pressure information into a 4-20mA analog signal and transmits it to the first constant pressure water supply controller. The first constant pressure water supply controller accurately reads the actual pressure value in the pipeline by receiving the 4-20mA signal value, and converts the received current signal into a 0-10V voltage signal and outputs it to the first inverter. The first inverter accurately calculates the number of pump revolutions according to the received pressure signal, and adjusts the output frequency to ensure that the circulating water pressure is maintained within the preset value range. In this way, the system can monitor the changes in the circulating water pressure in real time, and respond in time when the pressure exceeds or falls below the set range, and adjust the operating status of the pump to maintain a constant water pressure.

Claims

1. An electrical automatic control system for a heating circulation pump, characterized in that: It includes three-phase power supplies L1, L2, L3, a first AC motor M1, a second AC motor M2, a first 3P air switch QF1, a second 3P air switch QF2, a third 3P air switch QF3, a first 1P air switch QF4, a DC power supply, a first frequency converter U1, a first AC contactor 1KM, a first thermal relay 1FR, a second AC contactor 2KM, a second thermal relay 2FR, a conversion switch SA, a first constant pressure water supply controller, a first conversion switch SA1, an indicator light HG1, an indicator light HR1, and a first pressure sensor. Main circuit: The three-phase 380V power supply is connected to the second air switch QF2 through the first 3P air switch QF1. The lower side of the air switch QF2 is connected to the first frequency converter U1, the first AC contactor 1KM, the first thermal relay 1FR, and the first AC motor M1 in sequence; the lower side of the third air switch QF3 is connected to the second frequency converter U2, the second AC contactor 2KM, the second thermal relay 2FR, and the second load motor M2 in sequence; Control circuit: The first 1P air switch QF4 is respectively connected to the first conversion switch SA1, the first contactor 1KM normally open contact and the upper side of the normally closed contact, the lower side of the first contactor 1KM normally open contact is connected to the indicator light HG1, and the lower side of the contactor 1KM normally closed contact is connected to the indicator light HR1, the first conversion switch SA1 is connected to the first constant pressure water supply controller, and the G terminal of the first constant pressure water supply controller is connected to the 11 terminal of the first frequency converter, which is used to provide a 0-10V negative voltage to the first frequency converter; The D / A terminal of the first constant pressure water supply controller is connected to the first inverter 12 terminal, which is used to provide a 0-10V positive voltage to the first inverter to adjust the frequency of the first inverter. The CM terminal of the first constant pressure water supply controller is connected to the CM terminal of the first inverter. The FR terminal of the first constant pressure water supply controller is connected to the FWD terminal of the first inverter, which is used to provide an operation signal to the first inverter. The IN1 and IN2 terminals of the first constant pressure water supply controller are short-circuited and connected to the PIN2 terminal of the first pressure sensor. The PIN1 terminal of the first pressure sensor is connected to the 24V+ terminal of the DC power supply. The GND terminal of the high-pressure water supply controller is short-circuited and connected to the 24V-terminal of the DC power supply. The above connection is converted and output through the first pressure sensor to output an analog 4-20mA signal to the first constant-pressure water supply controller. The B1 terminal of the first constant-pressure water supply controller is connected to the upper end of the normally closed contact of the second AC contactor 2KM, and the lower end of the normally closed contact of the second AC contactor 2KM is connected to the AC contactor 1KM coil. The first AC contactor 1KM coil is connected to the normally closed contact of the first thermal relay 1FR, and the normally closed contact of the first thermal relay 1FR is connected to the N line, so that the first AC contactor 1KM coil is energized.

2. The electrical automatic control system for a heating circulation pump according to claim 1 is characterized in that: The main circuit and the control circuit are both provided with two identical sets, one for use and one for backup.

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