A generator cooling system employing a variable frequency blower

Abstract

This invention proposes a generator cooling system employing a variable frequency fan. By using a variable frequency fan to form a variable frequency heat dissipation system, the cooling system's heat dissipation rate is controlled according to the ambient temperature, thereby achieving engine cooling. The application of variable frequency fans in generator cooling systems offers significant advantages, primarily reflected in dynamic speed regulation, energy efficiency, and precise temperature control. Using variable frequency fans not only improves the efficiency and reliability of the cooling system but also significantly reduces energy consumption and maintenance costs, providing a strong guarantee for the long-term stable operation of the generator set.

Description

Technical Field

[0001] This utility model proposes a generator cooling system using a variable frequency fan, which relates to the field of generator technology. Background Technology

[0002] Conventional parallel generator cooling systems rely on the engine running to power a radiator fan for heat dissipation. However, the engine requires additional power to drive the radiator fan, reducing its effective output power, especially under full load, potentially leading to overall efficiency degradation. Both the radiator fan and the engine are mechanical components, susceptible to wear and failure. Regular maintenance and parts replacement increase operating costs and time. A radiator fan failure could cause engine overheating, potentially leading to more serious mechanical failures. This poses a potential risk to mission-critical equipment. Utility Model Content

[0003] In view of this, this utility model proposes a solution to the above problems by connecting a split-type variable frequency fan to the generator set to form a variable frequency cooling system. This system controls the heat dissipation rate of the cooling system based on the ambient temperature, thereby achieving engine cooling. The application of variable frequency fans in generator set cooling systems has significant advantages, mainly reflected in dynamic speed regulation, energy efficiency, and precise temperature control. By using variable frequency fans, not only can the efficiency and reliability of the cooling system be improved, but energy consumption and maintenance costs can also be significantly reduced, providing a strong guarantee for the long-term stable operation of the generator set.

[0004] A generator cooling system employing a variable frequency fan, characterized by comprising the following:

[0005] First air switch Q21, first contactor KM21, first thermal relay FR21, first variable frequency fan motor M21, first frequency converter INV1;

[0006] The second air switch Q22, the second contactor KM22, the second thermal relay FR22, and the motor M22 of the first variable frequency fan radiator;

[0007] The third air switch Q23, the third contactor KM23, the third thermal relay FR23, the motor M23 of the second variable frequency fan, and the second frequency converter INV2;

[0008] The fourth air switch Q24, the fourth contactor KM24, the fourth thermal relay FR24, and the motor M24 of the second variable frequency fan radiator;

[0009] First temperature transmitter HSTL-1, second temperature transmitter HSTL-2;

[0010] First control relay K21, second control relay K22, third control relay K23, fourth control relay K24;

[0011] The generator cooling system using a variable frequency fan includes a three-phase four-wire power supply circuit U1, V1, W1, and N1; wherein the three-phase four-wire power supply circuit includes a 380V three-phase three-wire power supply circuit powered by a 380V three-phase power supply.

[0012] The main circuit of the generator cooling system using a variable frequency fan includes a first variable frequency fan starting circuit, a first variable frequency fan radiator starting circuit, a second variable frequency fan starting circuit, and a second variable frequency fan radiator starting circuit.

[0013] The first variable frequency fan starting circuit includes a first air switch Q21, a first contactor KM21, a first thermal relay FR21, a motor M21 for the first variable frequency fan, and a first frequency converter INV1.

[0014] The starting circuit of the first variable frequency fan radiator includes a second air switch Q22, a second contactor KM22, a second thermal relay FR22, and a motor M22 for the first variable frequency fan radiator.

[0015] The second variable frequency fan starting circuit includes a third air switch Q23, a third contactor KM23, a third thermal relay FR23, a second variable frequency fan motor M23, and a second variable frequency drive INV2.

[0016] The starting circuit of the second variable frequency fan radiator includes a fourth air switch Q24, a fourth contactor KM24, a fourth thermal relay FR24, and a motor M24 for the second variable frequency fan radiator.

[0017] Furthermore, the first variable frequency fan starting circuit, the first variable frequency fan radiator starting circuit, the second variable frequency fan starting circuit, and the second variable frequency fan radiator starting circuit also include the following:

[0018] The first variable frequency fan starting circuit includes a first power supply circuit, which includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the first air switch Q21; the output terminal of the first air switch Q21 connected to the stationary contact of the normally open contact KM21-1 of the first contactor KM21; the moving contact of the normally open contact KM21-1 of the first contactor KM21 connected to one end of the first thermal relay FR21; the other end of the first thermal relay FR21 connected to the power input terminal of the first frequency converter INV1; and the power output terminal of the first frequency converter INV1 connected to the power input terminal of the motor M21 of the first variable frequency fan.

[0019] The starting circuit of the first variable frequency fan radiator includes a second power supply circuit, wherein the second power supply circuit includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the second air switch Q22; the output terminal of the second air switch Q22 connected to the stationary contact of the normally open contact KM22-1 of the second contactor KM22; the moving contact of the normally open contact KM22-1 of the second contactor KM22 connected to one end of the second thermal relay FR22; and the other end of the second thermal relay FR22 connected to the power input terminal of the motor M22 of the first variable frequency fan radiator.

[0020] The second variable frequency fan starting circuit includes a third power supply circuit, which includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the third air switch Q23; the output terminal of the third air switch Q23 connected to the stationary contact of the normally open contact KM23-1 of the third contactor KM23; the moving contact of the normally open contact KM23-1 of the third contactor KM23 connected to one end of the third thermal relay FR23; the other end of the third thermal relay FR23 connected to the power input terminal of the second frequency converter INV2; and the power output terminal of the second frequency converter INV2 connected to the power input terminal of the motor M23 of the second variable frequency fan.

[0021] The starting circuit of the second variable frequency fan radiator includes a fourth power supply circuit, which includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the fourth air switch Q24; the output terminal of the fourth air switch Q24 connected to the stationary contact of the normally open contact KM24-1 of the fourth contactor KM24; the moving contact of the normally open contact KM24-1 of the fourth contactor KM24 connected to one end of the fourth thermal relay FR24; and the other end of the second thermal relay FR24 connected to the power input terminal of the motor M24 of the second variable frequency fan radiator.

[0022] Furthermore, the first variable frequency fan starting circuit, the first variable frequency fan radiator starting circuit, the second variable frequency fan starting circuit, and the second variable frequency fan radiator starting circuit also include the following:

[0023] The first variable frequency fan starting circuit includes a first control branch, which includes a first normally open contact K21-1 of a first control relay K21, a normally closed contact FR21-1 of a first thermal relay FR21, and a first contactor KM21. The connection sequence of the first control branch includes the stationary contact of the first normally open contact K21-1 of the first control relay K21 connected in parallel to the single-phase interface of the output terminal of the first air switch Q21, the moving contact of the first normally open contact K21-1 of the first control relay K21 connected to one end of the normally closed contact FR21-1 of the first thermal relay FR21, one end of the normally closed contact FR21-1 of the first thermal relay FR21 connected to one end of the first contactor KM21, and the other end of the first contactor KM21 connected in parallel to N1 of the three-phase four-wire power supply circuit.

[0024] The first variable frequency fan radiator starting circuit includes a second control branch, which includes the second normally open contact K21-2 of the first control relay K21, the normally closed contact FR22-1 of the second thermal relay FR22, and the second contactor KM22. The connection sequence of the second control branch includes the stationary contact of the second normally open contact K21-2 of the first control relay K21 connected in parallel to the single-phase interface of the output terminal of the second air switch Q22, the moving contact of the second normally open contact K21-2 of the first control relay K21 connected to one end of the normally closed contact FR22-1 of the second thermal relay FR22, one end of the normally closed contact FR22-1 of the second thermal relay FR22 connected to one end of the second contactor KM22, and the other end of the second contactor KM22 connected in parallel to N1 of the three-phase four-wire power supply circuit.

[0025] The second variable frequency fan starting circuit includes a third control branch, which includes the first normally open contact K22-1 of the second control relay K22, the normally closed contact FR23-1 of the third thermal relay FR23, and the third contactor KM23. The connection sequence of the third control branch is as follows: the stationary contact of the first normally open contact K22-1 of the second control relay K22 is connected in parallel to the single-phase interface of the output terminal of the third air switch Q23; the moving contact of the first normally open contact K22-1 of the second control relay K22 is connected to one end of the normally closed contact FR23-1 of the third thermal relay FR23; one end of the normally closed contact FR23-1 of the third thermal relay FR23 is connected to one end of the third contactor KM23; and the other end of the third contactor KM23 is connected to N1 of the three-phase four-wire power supply circuit.

[0026] The second variable frequency fan radiator starting circuit includes a fourth control branch, which includes the second normally open contact K22-2 of the second control relay K22, the normally closed contact FR24-1 of the fourth thermal relay FR24, and the fourth contactor KM24. The connection sequence of the second control branch includes the stationary contact of the second normally open contact K22-2 of the first control relay K22 connected in parallel to the single-phase interface of the output terminal of the fourth air switch Q24, the moving contact of the second normally open contact K22-2 of the second control relay K22 connected to one end of the normally closed contact FR24-1 of the fourth thermal relay FR24, one end of the normally closed contact FR24-1 of the fourth thermal relay FR24 connected to one end of the fourth contactor KM24, and the other end of the fourth contactor KM24 connected in parallel to N1 of the three-phase four-wire power supply circuit.

[0027] Furthermore, the PE1 interface of the motor M21 of the first variable frequency fan and the PE3 interface of the first frequency converter INV1 are connected in parallel, and the PE2 interface of the motor M23 of the second variable frequency fan and the PE4 interface of the second frequency converter INV2 are connected in parallel.

[0028] Furthermore, the first frequency converter INV1 includes a first analog input interface for receiving 4-20mA analog signals; the second frequency converter INV1 includes a second analog input interface for receiving 4-20mA analog signals.

[0029] The first frequency converter INV1 includes a first digital input terminal, which is connected in series to the normally open contact K23-3 of the third control relay K23; the second frequency converter INV2 includes a second digital input terminal, which is connected in series to the normally open contact K24-3 of the fourth control relay K24.

[0030] Furthermore, the operating voltage range of the first frequency converter INV1 is 323V to 437V, and the operating frequency is 49.8Hz to 50.2Hz and 59.8Hz to 60.2Hz; the output voltage range of the first frequency converter INV1 is 0 to 380V; and the output voltage frequency of the first frequency converter INV1 is 0 to 3200Hz.

[0031] The second frequency converter INV2 has an operating voltage range of 323V to 437V and an operating frequency range of 49.8Hz to 50.2Hz and 59.8Hz to 60.2Hz; the first frequency converter INV1 has an output voltage range of 0 to 380V and an output voltage frequency range of 0 to 3200Hz.

[0032] Furthermore, the first temperature transmitter HSTL-1 has an analog output interface 1, with an analog output range of 4-20mA; the operating temperature range of the first temperature transmitter HSTL-1 is 20-85 degrees Celsius; the second temperature transmitter HSTL-2 has an analog output interface 2, with an analog output range of 4-20mA; the operating temperature range of the first temperature transmitter HSTL-2 is 20-85 degrees Celsius.

[0033] Furthermore, the engine cooling system also includes a remote signaling circuit, which is formed by connecting the spare normally open contact KM21-3 of the first contactor KM21, the spare normally open contact KM22-3 of the second contactor KM22, the spare normally open contact KM23-3 of the third contactor KM23, and the spare normally open contact KM24-3 of the fourth contactor KM24 in series.

[0034] Furthermore, one end of the first control relay K21 and one end of the second control relay K22 are connected in parallel as the live wire of the first external control power input; the other end of the first control relay K21 and the other end of the second control relay K22 are connected in parallel as the neutral wire of the first external control power input; one end of the third control relay K23 and one end of the fourth control relay K24 are connected in parallel as the live wire of the second external control power input; the other end of the third control relay K23 and the other end of the fourth control relay K24 are connected in parallel as the neutral wire of the second external control power input; wherein the first external control power supply and the second external control power supply are independent of each other.

[0035] Furthermore, the motor M21 of the first variable frequency fan adopts a star connection, the motor M23 of the second variable frequency fan adopts a star connection, the motor M22 of the first variable frequency fan radiator adopts a delta connection, and the motor M24 of the second variable frequency fan radiator adopts a delta connection.

[0036] This utility model has the following advantages:

[0037] This invention relates to a system for cooling generator sets during operation. Temperature sensors installed at key locations within the generator set monitor the ambient temperature in real time. The temperature data collected by the sensors is transmitted to the generator set controller and frequency converter via a temperature transmitter module. The frequency converter, based on the ambient temperature and a pre-set temperature control threshold, adjusts the fan speed and increases or decreases airflow and pressure upon receiving commands from the generator set controller to meet current cooling demands. During generator set operation, temperature and load may fluctuate; the frequency converter can adjust the fan speed in real time to ensure stable cooling performance. Temperature feedback from the ambient temperature sensor ensures correct execution of control commands, improving system response speed and control accuracy, and reducing energy waste. Attached Figure Description

[0038] Figure 1 This is the electrical wiring diagram of the main circuit of this utility model.

[0039] Figure 2 This is the electrical wiring diagram of the first frequency converter INV1 of this utility model.

[0040] Figure 3 This is the electrical wiring diagram for the second frequency converter INV2 of this utility model.

[0041] Figure 4 This is the electrical wiring diagram of the remote signaling circuit of this utility model.

[0042] Figure 5 This is the electrical wiring diagram for the first control relay K21 and the second control relay K22 of this utility model.

[0043] Figure 6 This is the electrical wiring diagram for the third control relay K23 and the fourth control relay K24 of this utility model.

[0044] Figure 7 This is the electrical wiring diagram for the first temperature transmitter HSTL-1 of this utility model.

[0045] Figure 8 This is the electrical wiring diagram for the second temperature transmitter HSTL-2 of this utility model. Detailed Implementation

[0046] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings.

[0047] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0048] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention; as used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise; furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0049] like Figures 1 to 8 As shown, a generator cooling system employing a variable frequency fan is characterized by comprising the following:

[0050] First air switch Q21, first contactor KM21, first thermal relay FR21, first variable frequency fan motor M21, first frequency converter INV1;

[0051] The second air switch Q22, the second contactor KM22, the second thermal relay FR22, and the motor M22 of the first variable frequency fan radiator;

[0052] The third air switch Q23, the third contactor KM23, the third thermal relay FR23, the motor M23 of the second variable frequency fan, and the second frequency converter INV2;

[0053] The fourth air switch Q24, the fourth contactor KM24, the fourth thermal relay FR24, and the motor M24 of the second variable frequency fan radiator;

[0054] First temperature transmitter HSTL-1, second temperature transmitter HSTL-2;

[0055] First control relay K21, second control relay K22, third control relay K23, fourth control relay K24;

[0056] The generator cooling system using a variable frequency fan includes a three-phase four-wire power supply circuit U1, V1, W1, and N1; wherein the three-phase four-wire power supply circuit includes a 380V three-phase three-wire power supply circuit powered by a 380V three-phase power supply.

[0057] The main circuit of the generator cooling system using a variable frequency fan includes a first variable frequency fan starting circuit, a first variable frequency fan radiator starting circuit, a second variable frequency fan starting circuit, and a second variable frequency fan radiator starting circuit.

[0058] The first variable frequency fan starting circuit includes a first air switch Q21, a first contactor KM21, a first thermal relay FR21, a motor M21 for the first variable frequency fan, and a first frequency converter INV1.

[0059] The starting circuit of the first variable frequency fan radiator includes a second air switch Q22, a second contactor KM22, a second thermal relay FR22, and a motor M22 for the first variable frequency fan radiator.

[0060] The second variable frequency fan starting circuit includes a third air switch Q23, a third contactor KM23, a third thermal relay FR23, a second variable frequency fan motor M23, and a second variable frequency drive INV2.

[0061] The starting circuit of the second variable frequency fan radiator includes a fourth air switch Q24, a fourth contactor KM24, a fourth thermal relay FR24, and a motor M24 for the second variable frequency fan radiator.

[0062] like Figure 1 As shown in one embodiment of this utility model, the first variable frequency fan starting circuit, the first variable frequency fan radiator starting circuit, the second variable frequency fan starting circuit, and the second variable frequency fan radiator starting circuit further include the following:

[0063] The first variable frequency fan starting circuit includes a first power supply circuit, which includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the first air switch Q21; the output terminal of the first air switch Q21 connected to the stationary contact of the normally open contact KM21-1 of the first contactor KM21; the moving contact of the normally open contact KM21-1 of the first contactor KM21 connected to one end of the first thermal relay FR21; the other end of the first thermal relay FR21 connected to the power input terminal of the first frequency converter INV1; and the power output terminal of the first frequency converter INV1 connected to the power input terminal of the motor M21 of the first variable frequency fan.

[0064] The starting circuit of the first variable frequency fan radiator includes a second power supply circuit, wherein the second power supply circuit includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the second air switch Q22; the output terminal of the second air switch Q22 connected to the stationary contact of the normally open contact KM22-1 of the second contactor KM22; the moving contact of the normally open contact KM22-1 of the second contactor KM22 connected to one end of the second thermal relay FR22; and the other end of the second thermal relay FR22 connected to the power input terminal of the motor M22 of the first variable frequency fan radiator.

[0065] The second variable frequency fan starting circuit includes a third power supply circuit, which includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the third air switch Q23; the output terminal of the third air switch Q23 connected to the stationary contact of the normally open contact KM23-1 of the third contactor KM23; the moving contact of the normally open contact KM23-1 of the third contactor KM23 connected to one end of the third thermal relay FR23; the other end of the third thermal relay FR23 connected to the power input terminal of the second frequency converter INV2; and the power output terminal of the second frequency converter INV2 connected to the power input terminal of the motor M23 of the second variable frequency fan.

[0066] The starting circuit of the second variable frequency fan radiator includes a fourth power supply circuit, which includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the fourth air switch Q24; the output terminal of the fourth air switch Q24 connected to the stationary contact of the normally open contact KM24-1 of the fourth contactor KM24; the moving contact of the normally open contact KM24-1 of the fourth contactor KM24 connected to one end of the fourth thermal relay FR24; and the other end of the second thermal relay FR24 connected to the power input terminal of the motor M24 of the second variable frequency fan radiator.

[0067] like Figure 1 As shown in one embodiment of this utility model, the first variable frequency fan starting circuit, the first variable frequency fan radiator starting circuit, the second variable frequency fan starting circuit, and the second variable frequency fan radiator starting circuit further include the following:

[0068] The first variable frequency fan starting circuit includes a first control branch, which includes a first normally open contact K21-1 of a first control relay K21, a normally closed contact FR21-1 of a first thermal relay FR21, and a first contactor KM21. The connection sequence of the first control branch includes the stationary contact of the first normally open contact K21-1 of the first control relay K21 connected in parallel to the single-phase interface of the output terminal of the first air switch Q21, the moving contact of the first normally open contact K21-1 of the first control relay K21 connected to one end of the normally closed contact FR21-1 of the first thermal relay FR21, one end of the normally closed contact FR21-1 of the first thermal relay FR21 connected to one end of the first contactor KM21, and the other end of the first contactor KM21 connected in parallel to N1 of the three-phase four-wire power supply circuit.

[0069] The first variable frequency fan radiator starting circuit includes a second control branch, which includes the second normally open contact K21-2 of the first control relay K21, the normally closed contact FR22-1 of the second thermal relay FR22, and the second contactor KM22. The connection sequence of the second control branch includes the stationary contact of the second normally open contact K21-2 of the first control relay K21 connected in parallel to the single-phase interface of the output terminal of the second air switch Q22, the moving contact of the second normally open contact K21-2 of the first control relay K21 connected to one end of the normally closed contact FR22-1 of the second thermal relay FR22, one end of the normally closed contact FR22-1 of the second thermal relay FR22 connected to one end of the second contactor KM22, and the other end of the second contactor KM22 connected in parallel to N1 of the three-phase four-wire power supply circuit.

[0070] The second variable frequency fan starting circuit includes a third control branch, which includes the first normally open contact K22-1 of the second control relay K22, the normally closed contact FR23-1 of the third thermal relay FR23, and the third contactor KM23. The connection sequence of the third control branch is as follows: the stationary contact of the first normally open contact K22-1 of the second control relay K22 is connected in parallel to the single-phase interface of the output terminal of the third air switch Q23; the moving contact of the first normally open contact K22-1 of the second control relay K22 is connected to one end of the normally closed contact FR23-1 of the third thermal relay FR23; one end of the normally closed contact FR23-1 of the third thermal relay FR23 is connected to one end of the third contactor KM23; and the other end of the third contactor KM23 is connected to N1 of the three-phase four-wire power supply circuit.

[0071] The second variable frequency fan radiator starting circuit includes a fourth control branch, which includes the second normally open contact K22-2 of the second control relay K22, the normally closed contact FR24-1 of the fourth thermal relay FR24, and the fourth contactor KM24. The connection sequence of the second control branch includes the stationary contact of the second normally open contact K22-2 of the first control relay K22 connected in parallel to the single-phase interface of the output terminal of the fourth air switch Q24, the moving contact of the second normally open contact K22-2 of the second control relay K22 connected to one end of the normally closed contact FR24-1 of the fourth thermal relay FR24, one end of the normally closed contact FR24-1 of the fourth thermal relay FR24 connected to one end of the fourth contactor KM24, and the other end of the fourth contactor KM24 connected in parallel to N1 of the three-phase four-wire power supply circuit.

[0072] like Figure 1As shown, in one embodiment of this utility model, the PE1 interface of the motor M21 of the first variable frequency fan and the PE3 interface of the first frequency converter INV1 are connected in parallel, and the PE2 interface of the motor M23 of the second variable frequency fan and the PE4 interface of the second frequency converter INV2 are connected in parallel.

[0073] like Figure 2 and Figure 3 As shown, in one embodiment of this utility model, the first frequency converter INV1 includes a first analog input interface for receiving 4-20mA analog signals; the second frequency converter INV1 includes a second analog input interface for receiving 4-20mA analog signals.

[0074] like Figure 2 and Figure 3 As shown, in one embodiment of this utility model, the first frequency converter INV1 includes a first digital input terminal, which is connected in series to the normally open contact K23-3 of the third control relay K23; the second frequency converter INV2 includes a second digital input terminal, which is connected in series to the normally open contact K24-3 of the fourth control relay K24.

[0075] Furthermore, the operating voltage range of the first frequency converter INV1 is 323V to 437V, and the operating frequency is 49.8Hz to 50.2Hz and 59.8Hz to 60.2Hz; the output voltage range of the first frequency converter INV1 is 0 to 380V; and the output voltage frequency of the first frequency converter INV1 is 0 to 3200Hz.

[0076] The second frequency converter INV2 has an operating voltage range of 323V to 437V and an operating frequency range of 49.8Hz to 50.2Hz and 59.8Hz to 60.2Hz; the first frequency converter INV1 has an output voltage range of 0 to 380V and an output voltage frequency range of 0 to 3200Hz.

[0077] like Figure 7 and Figure 8As shown, in one embodiment of this utility model, the first temperature transmitter HSTL-1 has an analog output interface 1, with an analog output range of 4-20mA; the operating temperature range of the first temperature transmitter HSTL-1 is 20-85 degrees Celsius; the second temperature transmitter HSTL-2 has an analog output interface 2, with an analog output range of 4-20mA; the operating temperature range of the first temperature transmitter HSTL-2 is 20-85 degrees Celsius. Further, the first temperature transmitter HSTL-1 uses a platinum resistance thermometer, designated PT100-2, and the second temperature transmitter HSTL-2 uses a platinum resistance thermometer, designated PT100-3.

[0078] like Figure 4 As shown, in one embodiment of this utility model, the engine cooling system further includes a remote signaling circuit, wherein the remote signaling circuit is formed by connecting the spare normally open contact KM21-3 of the first contactor KM21, the spare normally open contact KM22-3 of the second contactor KM22, the spare normally open contact KM23-3 of the third contactor KM23, and the spare normally open contact KM24-3 of the fourth contactor KM24 in series.

[0079] like Figure 5 and Figure 6 As shown, in one embodiment of this utility model, one end of the first control relay K21 and one end of the second control relay K22 are connected in parallel as the live wire of the first external control power input; the other end of the first control relay K21 and the other end of the second control relay K22 are connected in parallel as the neutral wire of the first external control power input; one end of the third control relay K23 and one end of the fourth control relay K24 are connected in parallel as the live wire of the second external control power input; the other end of the third control relay K23 and the other end of the fourth control relay K24 are connected in parallel as the neutral wire of the second external control power input; wherein the first external control power supply and the second external control power supply are independent of each other.

[0080] Furthermore, the motor M21 of the first variable frequency fan adopts a star connection, the motor M23 of the second variable frequency fan adopts a star connection, the motor M22 of the first variable frequency fan radiator adopts a delta connection, and the motor M24 of the second variable frequency fan radiator adopts a delta connection.

[0081] The workflow of this utility model is as follows:

[0082] First, close the first air switch Q21, the second air switch Q22, the third air switch Q23, and the fourth air switch Q24. Then, external commands supply power to the coils of the first control relay K21 and the second control relay K22 via lines 77-L and 77-N. The normally open contact K21-1 of the first control relay K21 closes, and the normally open contact K22-1 of the second control relay K22 closes. After the normally open contact K21-1 of the first control relay K21 and the normally open contact K22-1 of the second control relay K22 close, the first control branch, the second control branch, the third control branch, and the fourth control branch are all energized. After the first control branch, the second control branch, the third control branch, and the fourth control branch are all energized, the first contactor KM21, the second contactor KM22, the third contactor KM23, and the fourth contactor KM24 are all energized. Therefore, the normally open contact KM21-1 of the first contactor KM21, the normally open contact KM22-1 of the second contactor KM22, the normally open contact KM23-1 of the third contactor KM23, and the normally open contact KM24-1 of the fourth contactor KM24 are all closed. After the normally open contacts KM21-1 of the first contactor KM21, KM22-1 of the second contactor KM22, KM23-1 of the third contactor KM23, and KM24-1 of the fourth contactor KM24 are all closed, the input terminal of the first frequency converter INV1 in the first frequency converter fan starting circuit is energized, the motor M22 of the first frequency converter fan radiator in the first frequency converter fan radiator starting circuit is energized and starts, the input terminal of the second frequency converter INV2 in the second frequency converter fan starting circuit is energized, and the motor M24 of the second frequency converter fan radiator in the second frequency converter fan radiator starting circuit is energized and starts; at this time, the first frequency converter INV1 and the second frequency converter INV2 can start upon receiving the input command.

[0083] Among them, such as Figure 1 As shown, the input terminals of the first frequency converter INV1 consist of R1, S1 and T1, and the output terminals of the first frequency converter INV1 consist of U3, V3 and W3.

[0084] Among them, such as Figure 1 As shown, the input terminals of the second frequency converter INV2 consist of R2, S2 and T2, and the output terminals of the second frequency converter INV2 consist of U4, V4 and W4.

[0085] The first temperature transmitter HSTL-1 uses a PT100-2 resistor to detect the ambient temperature and converts it into a 4-20mA signal input to the first frequency converter INV1. When the temperature reaches the set value, an external command supplies power to the coil of the third control relay K23 through lines 78-L and 78-N. The normally open contact K23-3 of the third control relay K23 closes. After the input ports DI2 and COM of the first frequency converter INV1 receive the passive dry contact signal of the closed normally open contact K23-3 of the third control relay K23, the first frequency converter INV1 starts after being powered on at the input end. At the output end, the motor M21 of the first variable frequency fan is started in the form of frequency conversion and voltage conversion, so that the first variable frequency fan reaches the rated speed.

[0086] The second temperature transmitter HSTL-2 uses a PT100-3 resistor to detect the ambient temperature and converts it into a 4-20mA signal input to the first frequency converter INV2. When the temperature reaches the set value, an external command supplies power to the coil of the fourth control relay K24 through lines 78-L and 78-N. The normally open contact K24-3 of the fourth control relay K24 closes. After the input ports DI2 and COM of the second frequency converter INV2 receive the passive dry contact signal of the closed normally open contact K24-3 of the fourth control relay K24, the second frequency converter INV2 starts after being powered on at the input end. The output end starts the second frequency converter fan M24 in the form of frequency conversion and voltage conversion, and finally makes the second frequency converter fan reach the rated speed.

[0087] Furthermore, the first frequency converter INV1 controls the real-time speed of the variable frequency fan based on the current signal from the first temperature transmitter HSTL-1, thereby controlling the heat dissipation rate of the cooling system. The second frequency converter INV2 controls the real-time speed of the variable frequency fan based on the current signal from the second temperature transmitter HSTL-2, thereby controlling the heat dissipation rate of the cooling system.

[0088] The first control relay K21 is energized, and the command to close the normally open contact of the first control relay K21 is: line 77-L and line 77-N, which comes from the digital output port of the external controller.

[0089] The operating condition for triggering the motor M21 of the first variable frequency fan is that the external ambient temperature reaches the preset temperature of the motor M21 of the first variable frequency fan.

[0090] Among them, the command to energize the third control relay K23 and close the normally open contact of the third control relay K23 is: line 78-L and line 78-N, which comes from the digital output port of the external controller.

[0091] The operating condition for triggering the motor M23 of the second variable frequency fan is that the external ambient temperature reaches the preset temperature of the second variable frequency fan M23.

[0092] The operating conditions of the cooling fan M22 of inverter INV1 include: M22 starts to cool the inverter when it starts working.

[0093] The operating conditions of the cooling fan M24 of inverter INV2 include: M24 starts to cool the inverter when it starts working.

[0094] The first frequency converter INV1 controls the speed of the variable frequency fan based on the 4-20mA current signal output from the analog output port 1 provided by the first temperature transmitter HSTL-1.

[0095] The second frequency converter INV2 controls the speed of the variable frequency fan based on the 4-20mA current signal output from the analog output port 2 provided by the second temperature transmitter HSTL-2.

[0096] The remote signaling circuit is formed by connecting the spare normally open contact KM21-3 of the first contactor KM21, the spare normally open contact KM22-3 of the second contactor KM22, the spare normally open contact KM23-3 of the third contactor KM23, and the spare normally open contact KM24-3 of the fourth contactor KM24 in series. The remote signaling circuit can serve as a passive dry contact signal provided externally, indicating that the first contactor KM21, the second contactor KM22, the third contactor KM23, and the fourth contactor KM24 are all operating normally.

[0097] The above are preferred embodiments of this utility model. Any changes made to the technical solution of this utility model that do not exceed the scope of the technical solution of this utility model shall be protected within the scope of this utility model.

Claims

1. A generator cooling system employing a variable frequency fan, characterized in that, Includes the following: First air switch Q21, first contactor KM21, first thermal relay FR21, first variable frequency fan motor M21, first frequency converter INV1; The second air switch Q22, the second contactor KM22, the second thermal relay FR22, and the motor M22 of the first variable frequency fan radiator; The third air switch Q23, the third contactor KM23, the third thermal relay FR23, the motor M23 of the second variable frequency fan, and the second frequency converter INV2; The fourth air switch Q24, the fourth contactor KM24, the fourth thermal relay FR24, and the motor M24 of the second variable frequency fan radiator; First temperature transmitter HSTL-1, second temperature transmitter HSTL-2; First control relay K21, second control relay K22, third control relay K23, fourth control relay K24; The generator cooling system using a variable frequency fan includes a three-phase four-wire power supply circuit U1, V1, W1, and N1; wherein the three-phase four-wire power supply circuit includes a 380V three-phase three-wire power supply circuit powered by a 380V three-phase power supply. The main circuit of the generator cooling system using a variable frequency fan includes a first variable frequency fan starting circuit, a first variable frequency fan radiator starting circuit, a second variable frequency fan starting circuit, and a second variable frequency fan radiator starting circuit. The first variable frequency fan starting circuit includes a first air switch Q21, a first contactor KM21, a first thermal relay FR21, a motor M21 for the first variable frequency fan, and a first frequency converter INV1. The starting circuit of the first variable frequency fan radiator includes a second air switch Q22, a second contactor KM22, a second thermal relay FR22, and a motor M22 for the first variable frequency fan radiator. The second variable frequency fan starting circuit includes a third air switch Q23, a third contactor KM23, a third thermal relay FR23, a second variable frequency fan motor M23, and a second variable frequency drive INV2. The starting circuit of the second variable frequency fan radiator includes a fourth air switch Q24, a fourth contactor KM24, a fourth thermal relay FR24, and a motor M24 for the second variable frequency fan radiator.

2. The generator cooling system using a variable frequency fan according to claim 1, characterized in that, The first variable frequency fan starting circuit, the first variable frequency fan radiator starting circuit, the second variable frequency fan starting circuit, and the second variable frequency fan radiator starting circuit further include the following: The first variable frequency fan starting circuit includes a first power supply circuit, which includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the first air switch Q21; the output terminal of the first air switch Q21 connected to the stationary contact of the normally open contact KM21-1 of the first contactor KM21; the moving contact of the normally open contact KM21-1 of the first contactor KM21 connected to one end of the first thermal relay FR21; the other end of the first thermal relay FR21 connected to the power input terminal of the first frequency converter INV1; and the power output terminal of the first frequency converter INV1 connected to the power input terminal of the motor M21 of the first variable frequency fan. The starting circuit of the first variable frequency fan radiator includes a second power supply circuit, wherein the second power supply circuit includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the second air switch Q22; the output terminal of the second air switch Q22 connected to the stationary contact of the normally open contact KM22-1 of the second contactor KM22; the moving contact of the normally open contact KM22-1 of the second contactor KM22 connected to one end of the second thermal relay FR22; and the other end of the second thermal relay FR22 connected to the power input terminal of the motor M22 of the first variable frequency fan radiator. The second variable frequency fan starting circuit includes a third power supply circuit, which includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the third air switch Q23; the output terminal of the third air switch Q23 connected to the stationary contact of the normally open contact KM23-1 of the third contactor KM23; the moving contact of the normally open contact KM23-1 of the third contactor KM23 connected to one end of the third thermal relay FR23; the other end of the third thermal relay FR23 connected to the power input terminal of the second frequency converter INV2; and the power output terminal of the second frequency converter INV2 connected to the power input terminal of the motor M23 of the second variable frequency fan. The starting circuit of the second variable frequency fan radiator includes a fourth power supply circuit, which includes: a 380V three-phase three-wire power supply circuit connected to the input terminal of the fourth air switch Q24; the output terminal of the fourth air switch Q24 connected to the stationary contact of the normally open contact KM24-1 of the fourth contactor KM24; the moving contact of the normally open contact KM24-1 of the fourth contactor KM24 connected to one end of the fourth thermal relay FR24; and the other end of the second thermal relay FR24 connected to the power input terminal of the motor M24 of the second variable frequency fan radiator.

3. A generator cooling system using a variable frequency fan according to claim 2, characterized in that, The first variable frequency fan starting circuit, the first variable frequency fan radiator starting circuit, the second variable frequency fan starting circuit, and the second variable frequency fan radiator starting circuit further include the following: The first variable frequency fan starting circuit includes a first control branch, which includes a first normally open contact K21-1 of a first control relay K21, a normally closed contact FR21-1 of a first thermal relay FR21, and a first contactor KM21. The connection sequence of the first control branch includes the stationary contact of the first normally open contact K21-1 of the first control relay K21 connected in parallel to the single-phase interface of the output terminal of the first air switch Q21, the moving contact of the first normally open contact K21-1 of the first control relay K21 connected to one end of the normally closed contact FR21-1 of the first thermal relay FR21, one end of the normally closed contact FR21-1 of the first thermal relay FR21 connected to one end of the first contactor KM21, and the other end of the first contactor KM21 connected in parallel to N1 of the three-phase four-wire power supply circuit. The first variable frequency fan radiator starting circuit includes a second control branch, which includes the second normally open contact K21-2 of the first control relay K21, the normally closed contact FR22-1 of the second thermal relay FR22, and the second contactor KM22. The connection sequence of the second control branch includes the stationary contact of the second normally open contact K21-2 of the first control relay K21 connected in parallel to the single-phase interface of the output terminal of the second air switch Q22, the moving contact of the second normally open contact K21-2 of the first control relay K21 connected to one end of the normally closed contact FR22-1 of the second thermal relay FR22, one end of the normally closed contact FR22-1 of the second thermal relay FR22 connected to one end of the second contactor KM22, and the other end of the second contactor KM22 connected in parallel to N1 of the three-phase four-wire power supply circuit. The second variable frequency fan starting circuit includes a third control branch, which includes the first normally open contact K22-1 of the second control relay K22, the normally closed contact FR23-1 of the third thermal relay FR23, and the third contactor KM23. The connection sequence of the third control branch is as follows: the stationary contact of the first normally open contact K22-1 of the second control relay K22 is connected in parallel to the single-phase interface of the output terminal of the third air switch Q23; the moving contact of the first normally open contact K22-1 of the second control relay K22 is connected to one end of the normally closed contact FR23-1 of the third thermal relay FR23; one end of the normally closed contact FR23-1 of the third thermal relay FR23 is connected to one end of the third contactor KM23; and the other end of the third contactor KM23 is connected to N1 of the three-phase four-wire power supply circuit. The second variable frequency fan radiator starting circuit includes a fourth control branch, which includes the second normally open contact K22-2 of the second control relay K22, the normally closed contact FR24-1 of the fourth thermal relay FR24, and the fourth contactor KM24. The connection sequence of the second control branch includes the stationary contact of the second normally open contact K22-2 of the first control relay K22 connected in parallel to the single-phase interface of the output terminal of the fourth air switch Q24, the moving contact of the second normally open contact K22-2 of the second control relay K22 connected to one end of the normally closed contact FR24-1 of the fourth thermal relay FR24, one end of the normally closed contact FR24-1 of the fourth thermal relay FR24 connected to one end of the fourth contactor KM24, and the other end of the fourth contactor KM24 connected in parallel to N1 of the three-phase four-wire power supply circuit.

4. A generator cooling system using a variable frequency fan according to claim 1, characterized in that, The PE1 interface of the motor M21 of the first variable frequency fan and the PE3 interface of the first frequency converter INV1 are connected in parallel, and the PE2 interface of the motor M23 of the second variable frequency fan and the PE4 interface of the second frequency converter INV2 are connected in parallel.

5. A generator cooling system using a variable frequency fan according to claim 1, characterized in that, The first frequency converter INV1 includes a first analog input interface for receiving 4-20mA analog signals; the second frequency converter INV1 includes a second analog input interface for receiving 4-20mA analog signals. The first frequency converter INV1 includes a first digital input terminal, which is connected in series to the normally open contact K23-3 of the third control relay K23; the second frequency converter INV2 includes a second digital input terminal, which is connected in series to the normally open contact K24-3 of the fourth control relay K24.

6. A generator cooling system employing a variable frequency fan according to claim 1, characterized in that, The operating voltage range of the first frequency converter INV1 is 323V to 437V, and the operating frequency is 49.8Hz to 50.2Hz and 59.8Hz to 60.2Hz; the output voltage range of the first frequency converter INV1 is 0 to 380V; and the output voltage frequency of the first frequency converter INV1 is 0 to 3200Hz. The second frequency converter INV2 has an operating voltage range of 323V to 437V and an operating frequency range of 49.8Hz to 50.2Hz and 59.8Hz to 60.2Hz; the first frequency converter INV1 has an output voltage range of 0 to 380V and an output voltage frequency range of 0 to 3200Hz.

7. A generator cooling system using a variable frequency fan according to claim 1, characterized in that, The first temperature transmitter HSTL-1 has an analog output interface 1, with an analog output range of 4-20mA; the operating temperature range of the first temperature transmitter HSTL-1 is 20-85 degrees Celsius; the second temperature transmitter HSTL-2 has an analog output interface 2, with an analog output range of 4-20mA; the operating temperature range of the first temperature transmitter HSTL-2 is 20-85 degrees Celsius.

8. A generator cooling system using a variable frequency fan according to claim 1, characterized in that, The engine cooling system also includes a remote signaling circuit, which is formed by connecting the spare normally open contact KM21-3 of the first contactor KM21, the spare normally open contact KM22-3 of the second contactor KM22, the spare normally open contact KM23-3 of the third contactor KM23, and the spare normally open contact KM24-3 of the fourth contactor KM24 in series.

9. A generator cooling system using a variable frequency fan according to claim 1, characterized in that, One end of the first control relay K21 and one end of the second control relay K22 are connected in parallel as the live wire of the first external control power input; the other end of the first control relay K21 and the other end of the second control relay K22 are connected in parallel as the neutral wire of the first external control power input; one end of the third control relay K23 and one end of the fourth control relay K24 are connected in parallel as the live wire of the second external control power input; the other end of the third control relay K23 and the other end of the fourth control relay K24 are connected in parallel as the neutral wire of the second external control power input; wherein the first external control power supply and the second external control power supply are independent of each other.

10. A generator cooling system employing a variable frequency fan according to claim 1, characterized in that, The motor M21 of the first variable frequency fan is connected in a star configuration, the motor M23 of the second variable frequency fan is connected in a star configuration, the motor M22 of the first variable frequency fan radiator is connected in a delta configuration, and the motor M24 of the second variable frequency fan radiator is connected in a delta configuration.

Images