Energy-saving and efficient frequency converter room self-control cooling system and method

Abstract

The invention discloses an energy-saving and efficient frequency converter room self-control cooling system and method. Comprising a frequency converter chamber, a frequency converter arranged in the frequency converter chamber, a frequency conversion exhaust fan, a controller, a frequency converter exhaust temperature sensor, an exhaust electric air valve, an air supply electric air valve, an air internal circulation electric air valve, an air pipe and an outdoor air temperature sensor arranged outside the frequency converter chamber. Wherein the air pipe is communicated with the frequency converter chamber and the external environment; the frequency converter exhaust air temperature sensor is installed in the air pipe, the outdoor air temperature sensor is arranged on the outdoor side of the frequency converter, the exhaust electric air valve is arranged on an exhaust channel of the frequency converter chamber, the air supply electric air valve is arranged on an air supply channel of the frequency converter chamber, and the air internal circulation electric air valve is arranged on an internal air circulation channel of the frequency converter chamber. A natural cold source in outdoor air is preferentially utilized, the operation time of the air conditioner is shortened, energy-saving and efficient operation of the system is guaranteed, the environment requirement for normal operation of the frequency converter is met, and energy consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of inverter room cooling technology, and in particular to an energy-saving and efficient inverter room automatic cooling system and method. Background Technology

[0002] In industrial production, medium-voltage motors (such as fans, pumps, and compressors) often rely on frequency converters for their drive. Frequency converters continuously generate a large amount of heat during operation, and if this heat cannot be effectively cooled in a timely manner, it will directly affect their operational stability and service life. As a major energy consumer in industrial production, the energy consumption of the auxiliary cooling system for frequency converters is also significant. Therefore, developing efficient and energy-saving frequency converter cooling technologies has become an urgent need for the industry.

[0003] Currently, there are three main technical solutions for heat dissipation of frequency converters: the first is natural ventilation cooling, which achieves heat exchange through natural air circulation between the frequency converter room and the outside environment; the second is mechanical ventilation cooling, which uses cooling fans to force and accelerate airflow to enhance heat dissipation efficiency; and the third is air conditioning cooling, which uses an air conditioning system to actively cool and maintain a constant temperature environment inside the frequency converter room.

[0004] However, the aforementioned existing technical solutions all have significant shortcomings: when using natural ventilation cooling, the airflow speed is slow and uncontrolled, resulting in extremely poor cooling effect, which is difficult to meet the heat dissipation requirements of the frequency converter during high-load operation and is prone to causing the frequency converter to malfunction due to overheating; when using mechanical ventilation cooling, the cooling fan always runs at its highest speed, which can ensure heat dissipation capacity under extreme conditions, but the fan consumes a lot of energy and generates strong noise due to continuous high-speed operation, while also accelerating the wear of fan components and significantly shortening their service life; when using air conditioning cooling, the natural cold source in the outdoor air is not effectively utilized, and regardless of whether the outdoor temperature is suitable, the air conditioning compressor is relied upon for cooling, resulting in the air conditioning system operating at a high load for a long time, causing huge energy waste, which is not in line with the development trend of industrial energy conservation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an energy-efficient and high-performance automatic cooling system and method for inverter rooms. This invention mainly adopts a cooling method that combines mechanical ventilation and air conditioning. By optimizing and controlling parameters such as outdoor temperature, inverter temperature, fan frequency, and air conditioning cooling load, it prioritizes the use of natural cold sources in the outdoor air, reduces air conditioning operation time, ensures energy-efficient operation of the system, meets the environmental requirements for normal operation of the inverter, and reduces energy consumption.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an energy-efficient and highly effective automatic cooling system for a frequency converter room, comprising: The inverter room, controller, inverter installed inside the inverter room, inverter exhaust fan, inverter exhaust temperature sensor, exhaust electric damper, supply electric damper, air recirculation electric damper, air duct, and outdoor air temperature sensor installed outside the inverter room. The air duct connects the inverter room to the external environment; the inverter exhaust temperature sensor is installed inside the air duct, the outdoor air temperature sensor is located on the outside of the inverter room, the exhaust electric air valve is located on the exhaust duct of the inverter room, the supply electric air valve is located on the supply duct of the inverter room, and the internal air circulation electric air valve is located on the internal air circulation duct of the inverter room.

[0007] As a further technical solution, the controller is electrically connected to the variable frequency exhaust fan, the variable frequency exhaust temperature sensor, the outdoor air temperature sensor, the exhaust electric damper, the supply electric damper, and the air recirculation electric damper.

[0008] As a further technical solution, the inverter room is also equipped with a variable frequency fan and an air conditioner. The variable frequency fan is installed on the air supply duct of the inverter room, and both the variable frequency fan and the air conditioner are electrically connected to the controller.

[0009] As a further technical solution, the inverter room is also equipped with rainproof louvers and an air filter; at the air supply duct inlet of the inverter room, the rainproof louvers and the air filter are arranged sequentially along the air flow direction at the air supply duct inlet of the inverter room.

[0010] As a further technical solution, two rainproof louvers are provided, which are respectively installed on the exhaust duct and the air supply duct of the inverter room.

[0011] As a further technical solution, a humidity sensor is also installed on the outside of the inverter room to monitor the outdoor air humidity and is located near the outdoor air temperature sensor, and the humidity sensor is electrically connected to the controller.

[0012] Secondly, the present invention provides an energy-efficient and high-performance automatic cooling method for a frequency converter room, based on an energy-efficient and high-performance automatic cooling system for a frequency converter room as described in any one of the first aspects, comprising: The outdoor temperature is obtained by an outdoor air temperature sensor, and the temperature of the air discharged from the frequency converter is obtained by an inverter exhaust temperature sensor installed in the duct. When the outdoor temperature is less than or equal to the first temperature threshold and the temperature of the air discharged from the inverter is less than or equal to the second threshold, mechanical ventilation cooling is performed; when the outdoor temperature is greater than the third temperature threshold or the temperature of the air discharged from the inverter is greater than the second threshold, and the mechanical ventilation cooling operation does not meet the heat dissipation requirements, the operation is switched to air conditioning cooling; the mechanical ventilation cooling operation has a higher priority than the air conditioning cooling operation.

[0013] As a further technical solution, the mechanical ventilation and cooling operation is as follows: turn on the variable frequency exhaust fan and variable frequency supply fan, and simultaneously open the exhaust electric damper and supply electric damper, and close the air recirculation electric damper; continuously acquire the temperature of the air discharged from the frequency converter; if the temperature of the air discharged from the frequency converter is greater than or equal to the second threshold, increase the operating frequency of the variable frequency exhaust fan and variable frequency supply fan; if the temperature of the air discharged from the frequency converter is less than the fourth temperature threshold, decrease the operating frequency of the variable frequency exhaust fan and variable frequency supply fan.

[0014] As a further technical solution, the air conditioning cooling operation is as follows: turn on the air conditioner and the inverter exhaust fan, simultaneously open the air recirculation electric damper, turn off the inverter supply fan, and turn off the exhaust electric damper and the supply electric damper; continuously acquire the temperature of the air discharged from the inverter; if the temperature of the air discharged from the inverter is greater than or equal to the second threshold, increase the operating frequency of the inverter exhaust fan; if the temperature of the air discharged from the inverter is still greater than or equal to the second threshold, further increase the operating load of the air conditioner; if the temperature of the air discharged from the inverter is less than the fourth temperature threshold, first reduce the operating load of the air conditioner; when the operating load of the air conditioner no longer decreases, then reduce the operating frequency of the inverter exhaust fan.

[0015] As a further technical solution, outdoor humidity is obtained based on a humidity sensor; when the outdoor temperature is less than or equal to a first temperature threshold and the outdoor humidity is less than or equal to a humidity threshold, mechanical ventilation cooling is performed; otherwise, air conditioning cooling is performed.

[0016] One or more technical solutions of the present invention have the following beneficial effects: This invention employs a control strategy that prioritizes mechanical ventilation cooling over air conditioning cooling. When the outdoor temperature is ≤ a first temperature threshold and the inverter exhaust air temperature is ≤ a second threshold, mechanical ventilation cooling is prioritized to utilize natural cold sources, eliminating the need to start high-energy-consuming air conditioners. Simultaneously, in mechanical ventilation mode, the fan operating frequency can be dynamically adjusted based on the inverter exhaust air temperature, avoiding the energy waste of traditional mechanical ventilation's "full-load operation" and significantly reducing the cooling system's own energy consumption.

[0017] Through the dual monitoring of the outdoor air temperature sensor and the inverter exhaust air temperature sensor, the present invention realizes the precise switching between two modes of mechanical ventilation and air-conditioning cooling. When the outdoor temperature > the third temperature threshold or the inverter exhaust air temperature > the second threshold, and mechanical ventilation cannot meet the heat dissipation requirements, it automatically switches to air-conditioning cooling operation. Through the coordinated control strategy of "first adjusting the fan frequency and then adjusting the air-conditioning load", it ensures that the inverter exhaust air temperature is stable in the safe range of 38°C to 40°C, avoiding the overheating failure of the inverter caused by the poor cooling effect of traditional natural ventilation, and improving the operation stability and safety.

[0018] Under the mechanical ventilation cooling operation of the present invention, the fan dynamically adjusts the frequency according to the temperature, avoiding the high wear problem caused by continuous high-speed operation, and effectively extending the service life of the variable-frequency exhaust fan and the variable-frequency supply fan; the air-conditioning cooling operation is only started when the mechanical ventilation fails, reducing the loss of long-term high-load operation of the air conditioner and reducing the equipment maintenance and replacement frequency. At the same time, the air filter supporting the air duct can intercept outdoor sundries, avoid dust intrusion into the equipment interior and causing failures, and further reduce the maintenance cost. Brief Description of the Drawings

[0019] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0020] Figure 1 It is a schematic structural diagram of an energy-saving and efficient automatic cooling system for an inverter room of the present invention; Among them, 1 is the inverter room, 2 is the inverter, 3 is the variable-frequency exhaust fan, 4 is the variable-frequency supply fan, 5 is the controller, 6 is the air conditioner, 7 is the inverter exhaust air temperature sensor, 8 is the outdoor air temperature sensor, 9 is the rain-proof louver, 10 is the air filter, 11 is the air duct, 12 is the exhaust electric air valve, 13 is the supply electric air valve, and 14 is the air internal circulation electric air valve. Detailed Embodiments

[0021] It should be noted that the following detailed description is illustrative and aims to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0022] Embodiment I In this embodiment, an energy-saving and efficient automatic cooling system for an inverter room is provided, mainly adopting a cooling method of combined operation of mechanical ventilation and air conditioning. Through the optimized control of parameters such as outdoor temperature, inverter temperature, fan frequency, and air-conditioning cooling load, it preferentially utilizes the natural cold source in outdoor air, reduces the air-conditioning operation time, ensures the energy-saving and efficient operation of the system, meets the environmental requirements for the normal operation of the inverter, and reduces energy consumption.

[0023] like Figure 1 As shown in the structural diagram, the inverter room's automatic cooling system includes: The system includes a frequency converter room, controller, frequency converter installed inside the frequency converter room, frequency converter exhaust fan, frequency converter exhaust temperature sensor, exhaust electric damper, supply electric damper, air recirculation electric damper, duct, frequency converter supply fan, air conditioner, rainproof louvers, air filter, and outdoor air temperature and humidity sensors installed outside the frequency converter room.

[0024] The duct connects the inverter room to the external environment. The inverter exhaust temperature sensor is installed inside the duct, the outdoor air temperature sensor is located on the outside of the inverter, the exhaust electric damper is located on the exhaust duct of the inverter room, the supply electric damper is located on the supply duct of the inverter room, and the internal air circulation electric damper is located on the internal air circulation duct of the inverter room.

[0025] In this embodiment, a controller is installed outside the inverter room. Depending on the actual usage requirements, the controller can also be installed inside the inverter room. The controller is used to receive sensor signals, switch execution modes, and regulate the operation of components to realize the automated, precise, and energy-saving operation of the cooling system. The controller is electrically connected to the inverter exhaust fan, the inverter exhaust temperature sensor, the outdoor air temperature sensor, the exhaust electric damper, the supply electric damper, and the air recirculation electric damper.

[0026] In this embodiment, the variable frequency fan inside the inverter room is installed on the air supply duct of the inverter room, and both the variable frequency fan and the air conditioner are electrically connected to the controller. At the entrance of the air supply duct of the inverter room, rainproof louvers and air filters are sequentially installed along the air inflow direction. The rainproof louvers prevent rainwater from entering the ventilation system, and the air filters prevent dust, leaves, and other debris from the outdoor air from entering the ventilation system. Regular cleaning is required to ensure efficient system operation.

[0027] In this embodiment, two rainproof louvers are provided, which are respectively installed on the exhaust duct and the air supply duct of the inverter room.

[0028] In this embodiment, a humidity sensor is also installed outside the inverter room to monitor outdoor air humidity and is located near the outdoor air temperature sensor. The humidity sensor is electrically connected to the controller.

[0029] Example 2 This embodiment provides an energy-efficient and high-performance self-controlled cooling method for inverter rooms, based on an energy-efficient and high-performance self-controlled cooling system for inverter rooms provided in Embodiment 1, comprising: The outdoor temperature T8 is obtained based on the outdoor air temperature sensor 8, and the temperature T7 of the air discharged from the inverter is obtained through the inverter exhaust air temperature sensor 7 installed in the air duct 11. When the outdoor temperature T8 is less than or equal to the first temperature threshold (set to 37℃, which can be adjusted according to the actual climate conditions of the place of use, the inverter's temperature tolerance, etc.) and the temperature T7 of the air discharged from the inverter is less than or equal to the second threshold (set to 40℃, which can be adjusted according to the actual climate conditions of the place of use, the inverter's temperature tolerance, etc.), mechanical ventilation cooling operation is performed.

[0030] The mechanical ventilation and cooling operation is as follows: turn on the variable frequency exhaust fan 3 and variable frequency supply fan 4, and simultaneously open the exhaust electric damper 12 and the supply electric damper 13, while closing the air recirculation electric damper 14; continuously monitor the temperature of the air discharged from the frequency converter. If the temperature T7 of the air discharged from the frequency converter is greater than or equal to the second threshold (set to 40℃, which can be adjusted according to the actual climate conditions of the place of use, the temperature tolerance of the frequency converter, etc.), the controller 5 sends a signal to increase the operating frequency of the variable frequency exhaust fan 3 and the variable frequency supply fan 4; if the temperature T7 of the air discharged from the frequency converter is less than the fourth temperature threshold (set to 38℃, which can be adjusted according to the actual climate conditions of the place of use, the temperature tolerance of the frequency converter, etc.), then reduce the operating frequency of the variable frequency exhaust fan 3 and the variable frequency supply fan 4 to ensure that 38℃≤T7≤40℃, meet the requirements of the frequency converter 2 for ambient temperature, and reduce the energy consumption of the fans.

[0031] When the outdoor temperature exceeds the third temperature threshold or the temperature of the air discharged from the inverter exceeds the second threshold, and the mechanical ventilation cooling operation fails to meet the heat dissipation requirements, the operation will switch to air conditioning cooling. The mechanical ventilation cooling operation has a higher priority than the air conditioning cooling operation.

[0032] The air conditioning cooling operation is as follows: turn on air conditioner 6 and inverter exhaust fan 3, simultaneously open air recirculation electric damper 14, turn off inverter supply fan 4, and turn off exhaust electric damper 12 and supply electric damper 13; continuously acquire the temperature T7 of the air discharged from the inverter. If the temperature T7 of the air discharged from the inverter is greater than or equal to the second threshold (set to 40℃, which can be adjusted according to the actual climate conditions of the place of use, the inverter's temperature tolerance, etc.), the controller 5 sends a signal to increase the operating frequency of inverter exhaust fan 3. If the temperature T7 of the air discharged from the inverter is still greater than or equal to the second threshold, the operating load of air conditioner 6 is increased again. If the temperature of the air discharged from the inverter is less than the fourth temperature threshold, the operating load of air conditioner 6 is reduced first. When the operating load of air conditioner 6 reaches 30% of the full load, if T7 is still less than the fourth temperature threshold, the operating load of air conditioner 6 will no longer decrease. At this time, the operating frequency of inverter exhaust fan 3 is reduced again. By adjusting the operating load of air conditioner 6 and the frequency of variable frequency exhaust fan 3, the temperature is guaranteed to be 38℃≤T7≤40℃, thus meeting the requirements of variable frequency drive 2 for ambient temperature.

[0033] Air conditioner 6 is used to cool inverter 2, thereby achieving internal air circulation in inverter room 1 and reducing the amount of outdoor air flowing into the room, which would increase the operating load of air conditioner 6.

[0034] In this embodiment, considering that introducing outdoor air may cause condensation inside the inverter cabinet when the outdoor temperature is suitable but the humidity is extremely high, which is extremely dangerous, the outdoor humidity H8 is also obtained based on the humidity sensor; when the outdoor temperature T8 is less than or equal to the first temperature threshold and the outdoor humidity H8 is less than or equal to the humidity threshold (80%RH), mechanical ventilation cooling is performed; otherwise, air conditioning cooling is performed.

[0035] In this embodiment, mechanical ventilation is preferred for cooling the frequency converter, making full use of the natural cold source in the air and reducing the power consumption of the air conditioner; at the same time, mechanical ventilation cooling and air conditioning cooling are set up to ensure normal heat dissipation of the frequency converter and increase the safety of operation.

[0036] The above method optimizes the system's control logic, makes full use of the low outdoor air temperature in spring, autumn and winter, as well as at night, and uses mechanical ventilation as much as possible to cool the frequency converter.

[0037] Various modifications and variations of this invention will be apparent to those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An energy-efficient and high-performance automatic cooling system for a frequency converter room, characterized in that, include: The inverter room, controller, inverter installed inside the inverter room, inverter exhaust fan, inverter exhaust temperature sensor, exhaust electric damper, supply electric damper, air recirculation electric damper, air duct, and outdoor air temperature sensor installed outside the inverter room. The air duct connects the inverter room to the external environment; the inverter exhaust temperature sensor is installed inside the air duct, the outdoor air temperature sensor is located on the outside of the inverter room, the exhaust electric air valve is located on the exhaust duct of the inverter room, the supply electric air valve is located on the supply duct of the inverter room, and the internal air circulation electric air valve is located on the internal air circulation duct of the inverter room.

2. The energy-saving and efficient inverter room self-controlled cooling system as described in claim 1, characterized in that, The controller is electrically connected to the variable frequency exhaust fan, the variable frequency exhaust temperature sensor, the outdoor air temperature sensor, the exhaust electric valve, the supply electric valve, and the air recirculation electric valve.

3. The energy-saving and efficient inverter room self-controlled cooling system as described in claim 1, characterized in that, The inverter room is also equipped with an inverter fan and an air conditioner. The inverter fan is installed on the air supply duct of the inverter room, and both the inverter fan and the air conditioner are electrically connected to the controller.

4. The energy-saving and efficient inverter room self-controlled cooling system as described in claim 1, characterized in that, The inverter room is also equipped with rainproof louvers and an air filter; at the air supply duct inlet of the inverter room, the rainproof louvers and the air filter are arranged sequentially along the air flow direction at the air supply duct inlet of the inverter room.

5. The energy-saving and efficient inverter room self-controlled cooling system as described in claim 4, characterized in that, Two rainproof louvers are provided, one on the exhaust duct and the other on the supply duct of the inverter room.

6. The energy-saving and efficient inverter room self-controlled cooling system as described in claim 1, characterized in that, A humidity sensor is also installed on the outside of the inverter room to monitor outdoor air humidity and is located near the outdoor air temperature sensor. The humidity sensor is electrically connected to the controller.

7. An energy-efficient and high-performance automatic cooling method for a frequency converter room, based on the energy-efficient and high-performance automatic cooling system for a frequency converter room as described in any one of claims 1-6, characterized in that, include: The outdoor temperature is obtained by an outdoor air temperature sensor, and the temperature of the air discharged from the frequency converter is obtained by an inverter exhaust temperature sensor installed in the duct. When the outdoor temperature is less than or equal to the first temperature threshold and the temperature of the air discharged from the inverter is less than or equal to the second threshold, mechanical ventilation cooling is performed; when the outdoor temperature is greater than the third temperature threshold or the temperature of the air discharged from the inverter is greater than the second threshold, and the mechanical ventilation cooling operation does not meet the heat dissipation requirements, the operation is switched to air conditioning cooling; the mechanical ventilation cooling operation has a higher priority than the air conditioning cooling operation.

8. The energy-saving and efficient automatic cooling method for a frequency converter room as described in claim 7, characterized in that, The mechanical ventilation and cooling operation is as follows: turn on the variable frequency exhaust fan and variable frequency supply fan, and simultaneously open the exhaust electric damper and supply electric damper, and close the air recirculation electric damper; continuously acquire the temperature of the air discharged from the frequency converter; if the temperature of the air discharged from the frequency converter is greater than or equal to the second threshold, increase the operating frequency of the variable frequency exhaust fan and variable frequency supply fan; if the temperature of the air discharged from the frequency converter is less than the fourth temperature threshold, decrease the operating frequency of the variable frequency exhaust fan and variable frequency supply fan.

9. The energy-saving and efficient automatic cooling method for a frequency converter room as described in claim 7, characterized in that, The air conditioning cooling operation is as follows: turn on the air conditioner and the inverter exhaust fan, simultaneously open the air recirculation electric damper, turn off the inverter supply fan, and turn off the exhaust electric damper and the supply electric damper; continuously monitor the temperature of the air discharged from the inverter; if the temperature of the air discharged from the inverter is greater than or equal to the second threshold, increase the operating frequency of the inverter exhaust fan; if the temperature of the air discharged from the inverter is still greater than or equal to the second threshold, further increase the operating load of the air conditioner; if the temperature of the air discharged from the inverter is less than the fourth temperature threshold, first reduce the operating load of the air conditioner; when the operating load of the air conditioner no longer decreases, then reduce the operating frequency of the inverter exhaust fan.

10. The energy-saving and efficient automatic cooling method for a frequency converter room as described in claim 7, characterized in that, Outdoor humidity is obtained based on a humidity sensor; when the outdoor temperature is less than or equal to a first temperature threshold and the outdoor humidity is less than or equal to a humidity threshold, mechanical ventilation cooling is performed; otherwise, air conditioning cooling is performed.

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