Marine air-cooled air conditioner compression control circuit and control method thereof

Abstract

The application relates to a control circuit of a marine air-cooled air conditioner compressor and a control method thereof. The control circuit integrates a starting control circuit, an oil level control circuit, a low-voltage control circuit, a protection circuit, a restart delay circuit, a compressor starting circuit, a compressor operation circuit, a cooling fan operation circuit and a fault test circuit to control the starting and stopping of the compressor and the cooling fan, delay restart, back exhaust pressure detection control, oil level detection control, over-temperature and overload detection control, realize operation detection, starting, stopping, restart and convenient fault detection and elimination, and is favorable for marine air-cooled air conditioner compressor control and improves the automation degree.

Description

Technical Field

[0001] This invention relates to a marine air-cooled air conditioner, specifically a marine air-cooled air conditioner compressor control circuit and its control method. Background Technology

[0002] In marine air-cooled air conditioners, there are many issues that affect their performance and lifespan. These issues range from power supply to air pressure, temperature, overload, and compressor damage during restart. Existing controls for these issues cannot be integrated and require manual identification and control, which is not conducive to automated control. In addition, troubleshooting these faults is also quite complex and cannot be done easily. Summary of the Invention

[0003] This invention provides a circuit and its control method that can automatically balance the performance, safety, and lifespan control of air conditioning compressors and cooling fans.

[0004] The technical solution adopted in this invention is: a control circuit for a marine air-cooled air conditioning compressor, characterized in that: a start-up control circuit, an oil level control circuit, a low-pressure control circuit, a protection circuit, a restart delay circuit, a compressor start-up circuit, a compressor running circuit, and a cooling fan running circuit are connected in parallel to the control power supply; the start-up control circuit has a first contact of a start button and a control relay connected in series, and a first normally open switch of the control relay and a normally open switch of the oil level power-off delay relay connected in series connected in parallel to the first contact of the start button; the oil level control circuit has an oil level switch and an oil level power-off delay relay connected in series, and a second normally open switch of the control relay and a first normally closed switch of the running relay connected in series connected in parallel to the oil level switch; the low-pressure control circuit has a compressor return port low-pressure control switch and a low-pressure power-off delay relay connected in series; the protection circuit includes a compressor exhaust port fault circuit connected in series. The compressor starts with a fault protection switch, a control relay third normally open switch, an over-temperature protection switch, a compressor overload protection switch, a cooling fan overload switch, and a protection relay. The restart delay circuit is connected in series with a running relay second normally closed switch and a energized delay relay. The compressor starting circuit is connected in series with a start button second contact, a stop button, a protection relay normally open switch, and a start relay. The start button second contact is connected in parallel with a start relay first normally open switch. The compressor running circuit is connected in series with a start relay second normally open switch, an energized delay relay normally open switch, a low-voltage delay relay normally open switch, and a compressor running contactor. The energized delay relay normally open switch is connected in parallel with a compressor running contactor first normally open switch. The cooling fan running circuit is connected in series with a compressor running contactor second normally open switch, a compressor exhaust port high-pressure control switch, and a fan running contactor.

[0005] A power protection switch is also connected in series in the protection circuit. The contacts of the power protection switch are in the protection circuit, and the coil of the power protection switch is in the three-phase main circuit of the control power supply.

[0006] It also includes a fault test circuit, which includes short-circuit circuits with short-circuit switches connected in parallel to the compressor discharge port fault protection switch, power protection switch, oil level protection switch, over-temperature protection switch, compressor overload protection switch, and cooling fan overload switch.

[0007] A protection indicator light is connected in parallel to the protection relay.

[0008] The coil of the over-temperature protection switch is connected in series with the control power supply via the stop button.

[0009] A control method for a marine air-cooled air conditioning compressor, characterized by the following steps:

[0010] (1) Circuit power-on: After the second normally closed switch of the running relay of the restart delay circuit is turned on, the energized delay relay is energized. After the delay time, the normally open switch of the energized delay relay of the compressor running circuit is closed, the compressor running contactor is not connected, and the compressor is in the standby state.

[0011] (2) Button start: Press the start button, the start button jogs to connect the first contact of the start button, the control relay is energized, the first and second normally open switches of the control relay are closed, the oil level de-energization delay relay is energized, the normally open switch of the oil level de-energization delay relay is closed, the first normally open switch of the control relay and the normally open switch of the oil level de-energization delay relay lock the first contact of the start button that was jogged and released, and the control relay is continuously energized;

[0012] (3) Low pressure control and protection circuit control: The low pressure control switch at the compressor return port detects the pressure at the compressor return port. If the pressure is normal, the low pressure power failure delay relay is activated. The low pressure power failure delay relay is energized, and the normally open switch of the power failure delay relay on the compressor running circuit is closed. When the button is pressed to start, the third normally open switch of the control relay is closed. The power protection switch on the three-phase main circuit of the control power supply is closed when it is normally connected. The compressor exhaust port fault protection switch, over-temperature protection switch, compressor overload protection switch, and cooling fan overload switch on the protection circuit are all connected without fault. The protection relay is energized, and the protection indicator light on the protection relay is normal.

[0013] (4) Compressor operation control: When the protection relay is energized, the normally open switch of the protection relay is closed. When the starting relay is energized, the first and second normally open switches of the starting relay are closed, locking the connection of the compressor starting circuit. At the same time, the compressor operation circuit is connected. When the compressor operation contactor is energized, the first and second normally closed switches of the compressor operation contactor are opened. When the energized delay relay is de-energized, the normally open switch of the energized delay relay is opened. When the compressor operation contactor is closed, the first normally open switch of the compressor operation contactor is connected, locking the de-energized delay relay normally open, ensuring that the compressor operation contactor remains energized and the compressor operates normally.

[0014] (5) Cooling fan operation control: The high pressure control switch at the compressor exhaust port detects the compressor exhaust port pressure and keeps it connected. When the second normally open switch of the compressor operation contactor is turned on, the fan operation contactor is energized, and the cooling fan operates normally.

[0015] (6) Shutdown control: Pressing the stop button will momentarily disconnect the compressor starting circuit, de-energize the starting relay, open the first and second normally open switches of the starting relay, keep the compressor starting circuit and compressor running circuit disconnected, de-energize the compressor running contactor, open the first and second normally open switches of the compressor running contactor, disconnect the cooling fan running circuit, and stop the compressor and cooling fan.

[0016] (7) Delayed start control: The normally closed switch of the compressor running contactor closes after the machine stops, and the energized delay relay is energized. During the delay time of the energized delay relay, the normally open switch of the energized delay relay on the compressor running circuit does not close. If the start button is pressed at this time, the compressor running contactor will never be energized, and the compressor will not run. After the delay time, the normally open switch of the energized delay relay remains closed. After that, if the start button is pressed, the compressor will start again after the delay protection.

[0017] (8) Oil level protection control: When the compressor is running, the normally closed switch of the compressor running contactor is opened. When the oil level is not sufficient or too high, the oil level switch is disconnected and the oil level de-energization delay relay is de-energized. The normally open switch of the oil level de-energization delay relay is opened and closed, and the delay control relay is de-energized, delaying the shutdown of the compressor and cooling fan.

[0018] (9) Fault protection control: If any of the compressor discharge port fault protection switch, power supply protection switch, over-temperature protection switch, compressor overload protection switch, or cooling fan overload switch detects the corresponding compressor discharge port fault, power supply fault, compressor over-temperature, compressor overload, or cooling fan overload signal, the protection circuit will be disconnected, the protection relay will be de-energized, the normally open switch of the protection relay will open and close, the compressor starting circuit will be de-energized, and the starting relay will be de-energized, thereby controlling the compressor running circuit and cooling fan running circuit to de-energize, the compressor running contactor and cooling fan running contactor to de-energize, and the compressor and cooling fan will be shut down for protection.

[0019] (10) Fault detection: Press the multiple short-circuit switches on the short-circuit circuit respectively, and short-circuit the compressor exhaust port fault protection switch, power protection switch, oil level protection switch, over-temperature protection switch, compressor overload protection switch and cooling fan overload switch in sequence to check whether the protection switch of the corresponding short-circuit switch is disconnected, thereby detecting the fault point corresponding to the protection switch.

[0020] This invention integrates a start-up control circuit, an oil level control circuit, a low-pressure control circuit, a protection circuit, a restart delay circuit, a compressor start-up circuit, a compressor running circuit, a cooling fan running circuit, and a fault testing circuit into one unit. It provides start-up and shutdown control, delayed restart, return and exhaust pressure detection control, oil level detection control, over-temperature and overload detection control for the compressor and cooling fan. It enables convenient detection and troubleshooting of operation, start-up, shutdown, restart, and faults, which is beneficial for the compressor control of marine air-cooled air conditioners and improves the degree of automation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the control principle of the present invention.

[0022] In the diagram: Control power supply AC, Start control circuit 1, Start button first contact SB1-1, Start button first contact SB1-2, Start relay KA1, Start relay first normally open switch KA1-1, Start relay second normally open switch KA1-2, Start relay third normally open switch KA1-3, Oil level control circuit 2, Oil level switch OLC, Oil level power failure delay relay KT1, Oil level power failure delay relay normally open switch KT1-1, Low voltage control circuit 3, Low voltage control switch LP, Low voltage power failure delay relay KT2, Low voltage power failure delay relay normally open switch KT2-1, Protection circuit 4, Fault protection switch HP1, Power protection switch K, Over-temperature protection switch STW, Compressor overload protection switch FR, Cooling fan overload protection switch FR1, Protection relay K A2, Protective relay normally open switch KA2-1, Protective indicator light HL, Restart delay circuit 5, Power-on delay relay KT3, Power-on delay relay normally open switch KT3-1, Compressor start circuit 6, Stop button first contact SB2-1, Stop button second contact SB2-2, Start relay KA3, Start relay first normally open switch KA3-1, Start relay second normally open switch KA3-2, Compressor running circuit 7, Running relay KM, Running relay first normally closed switch KM-1, Running relay second normally closed switch KM-2, Running relay first normally open switch KM-3, Running relay second normally open switch KM-4, Cooling fan running circuit 8, High pressure control switch HP2, Fan running contactor KM1, Short-circuit circuit 9, Short-circuit switch SB3. Detailed Implementation

[0023] The following description, in conjunction with the accompanying drawings and embodiments, provides further details.

[0024] Figure 1The diagram shows a control circuit for a marine air-cooled air conditioning compressor. The circuit comprises a start-up control circuit 1, an oil level control circuit 2, a low-pressure control circuit 3, a protection circuit 4, a restart delay circuit 5, a compressor start-up circuit 6, a compressor running circuit 7, a cooling fan running circuit 8, and a short-circuit circuit 9, all connected in parallel to the control power supply AC. The start-up control circuit 1 has a start button first contact SB1-1 and a control relay KA1 connected in series. The start button first contact SB1-1 has a control relay first normally open switch KA1-1 connected in series and an oil level power-off delay relay normally open switch KT1-1 connected in parallel. The oil level control circuit 2 has an oil level switch OLC and an oil level power-off delay relay KT1 connected in series. The oil level switch has a control relay second normally open switch KA1-2 connected in series and a running relay first normally closed switch KM-1 connected in parallel. The low-pressure control circuit 3 has a low-pressure control switch LP located at the compressor return port and a low-pressure power-off delay relay KT2 connected in series. Protection circuit 4 includes, in series, a fault protection switch HP1 at the compressor discharge port, a power protection switch K, a control relay third normally open switch KA1-3, an over-temperature protection switch STW, a compressor overload protection switch FR, a cooling fan overload switch FR1, and a protection relay KA2. A protection indicator light HL is connected in parallel to the protection relay. Restart delay circuit 5 includes a running relay second normally closed switch KM-2 and a energized delay relay KT3 connected in series. Compressor starting circuit 6 includes a start button second contact SB1-2, a stop button first contact SB2-1, a protection relay normally open switch KA2-1, and a starting relay KA3 connected in series. A starting relay first normally open switch KA3-1 is connected in parallel to the start button second contact SB1-2. The compressor operating circuit 7 is connected in series with the second normally open switch of the starting relay KA3-2, the normally open switch of the energized time delay relay KT3-1, the normally open switch of the low-pressure time delay relay KT2-1, and the compressor operating contactor KM. The normally open switch of the energized time delay relay KT3-1 is connected in parallel with the first normally open switch of the compressor operating contactor KM-3. The cooling fan operating circuit 8 is connected in series with the second normally open switch of the compressor operating contactor KM-4, the high-pressure control switch of the compressor discharge port HP2, and the fan operating contactor KM1.

[0025] In this embodiment, the contacts of the power protection switch K are on the protection circuit, and the coil of the power protection switch K is on the three-phase main circuit of the control power supply AC.

[0026] In this embodiment, a short-circuit circuit 9 with a short-circuit switch SB3 is connected in parallel to the compressor exhaust port fault protection switch, power protection switch, oil level protection switch, over-temperature protection switch, compressor overload protection switch, and cooling fan overload switch.

[0027] In this embodiment, the coil of the over-temperature protection switch STW is connected in series with the control power supply AC via the second contact SB2-2 of the stop button. When a fault occurs, the stop button fails. If the over-temperature protection switch fails and needs maintenance, its coil can be disconnected by pressing the second contact SB2-2 of the stop button.

[0028] The control method for a marine air-cooled air conditioning compressor of the present invention includes the following steps:

[0029] (1) Circuit power-on: After the second normally closed switch of the running relay of the restart delay circuit is turned on, the energized delay relay is energized. After the delay time, the normally open switch of the energized delay relay of the compressor running circuit is closed, the compressor running contactor is not connected, and the compressor is in the standby state.

[0030] (2) Button start: Press the start button, the start button jogs to connect the first contact of the start button, the control relay is energized, the first and second normally open switches of the control relay are closed, the oil level de-energization delay relay is energized, the normally open switch of the oil level de-energization delay relay is closed, the first normally open switch of the control relay and the normally open switch of the oil level de-energization delay relay lock the first contact of the start button that was jogged and released, and the control relay is continuously energized;

[0031] (3) Low pressure control and protection circuit control: The low pressure control switch at the compressor return port detects the pressure at the compressor return port. If the pressure is normal, the low pressure power failure delay relay is activated. The low pressure power failure delay relay is energized, and the normally open switch of the power failure delay relay on the compressor running circuit is closed. When the button is pressed to start, the third normally open switch of the control relay is closed. The power protection switch on the three-phase main circuit of the control power supply is closed when it is normally connected. The compressor exhaust port fault protection switch, over-temperature protection switch, compressor overload protection switch, and cooling fan overload switch on the protection circuit are all connected without fault. The protection relay is energized, and the protection indicator light on the protection relay is normal.

[0032] (4) Compressor operation control: When the protection relay is energized, the normally open switch of the protection relay is closed. When the starting relay is energized, the first and second normally open switches of the starting relay are closed, locking the connection of the compressor starting circuit. At the same time, the compressor operation circuit is connected. When the compressor operation contactor is energized, the first and second normally closed switches of the compressor operation contactor are opened. When the energized delay relay is de-energized, the normally open switch of the energized delay relay is opened. When the compressor operation contactor is closed, the first normally open switch of the compressor operation contactor is connected, locking the de-energized delay relay normally open, ensuring that the compressor operation contactor remains energized and the compressor operates normally.

[0033] (5) Cooling fan operation control: The high pressure control switch at the compressor exhaust port detects the compressor exhaust port pressure and keeps it connected. When the second normally open switch of the compressor operation contactor is turned on, the fan operation contactor is energized, and the cooling fan operates normally.

[0034] (6) Shutdown control: Pressing the stop button will momentarily disconnect the compressor starting circuit, de-energize the starting relay, open the first and second normally open switches of the starting relay, keep the compressor starting circuit and compressor running circuit disconnected, de-energize the compressor running contactor, open the first and second normally open switches of the compressor running contactor, disconnect the cooling fan running circuit, and stop the compressor and cooling fan.

[0035] (7) Delayed start control: The normally closed switch of the compressor running contactor closes after the machine stops, and the energized delay relay is energized. During the delay time of the energized delay relay, the normally open switch of the energized delay relay on the compressor running circuit does not close. If the start button is pressed at this time, the compressor running contactor will never be energized, and the compressor will not run. After the delay time, the normally open switch of the energized delay relay remains closed. After that, if the start button is pressed, the compressor will start again after the delay protection.

[0036] (8) Oil level protection control: When the compressor is running, the normally closed switch of the compressor running contactor is opened. When the oil level is not sufficient or too high, the oil level switch is disconnected and the oil level de-energization delay relay is de-energized. The normally open switch of the oil level de-energization delay relay is opened and closed, and the delay control relay is de-energized, delaying the shutdown of the compressor and cooling fan.

[0037] (9) Fault protection control: If any of the compressor discharge port fault protection switch, power supply protection switch, over-temperature protection switch, compressor overload protection switch, or cooling fan overload switch detects the corresponding compressor discharge port fault, power supply fault, compressor over-temperature, compressor overload, or cooling fan overload signal, the protection circuit will be disconnected, the protection relay will be de-energized, the normally open switch of the protection relay will open and close, the compressor starting circuit will be de-energized, and the starting relay will be de-energized, thereby controlling the compressor running circuit and cooling fan running circuit to de-energize, the compressor running contactor and cooling fan running contactor to de-energize, and the compressor and cooling fan will be shut down for protection.

[0038] (10) Fault detection: Press the multiple short-circuit switches on the short-circuit circuit respectively, and short-circuit the compressor exhaust port fault protection switch, power protection switch, oil level protection switch, over-temperature protection switch, compressor overload protection switch and cooling fan overload switch in sequence to check whether the protection switch of the corresponding short-circuit switch is disconnected, thereby detecting the fault point corresponding to the protection switch.

Claims

1. A control circuit for a marine air-cooled air conditioning compressor, characterized in that: The control power supply includes a starting control circuit, an oil level control circuit, a low-pressure control circuit, a protection circuit, a restart delay circuit, a compressor starting circuit, a compressor running circuit, and a cooling fan running circuit connected in parallel. The starting control circuit has a first contact of the start button and a control relay connected in series. The first contact of the start button has a first normally open switch of the control relay and a normally open switch of the oil level power-off delay relay connected in series in parallel. The oil level control circuit has an oil level switch and an oil level power-off delay relay connected in series in series. The oil level switch has a second normally open switch of the control relay and a first normally closed switch of the running relay connected in parallel in series in series in parallel. The low-pressure control circuit has a compressor return port low-pressure control switch and a low-pressure power-off delay relay connected in series in series. The protection circuit includes a compressor exhaust port fault protection switch and a third normally open switch of the control relay connected in series in sequence. The compressor includes an over-temperature protection switch, a compressor overload protection switch, a cooling fan overload switch, and a protection relay. The restart delay circuit is connected in series with a second normally closed switch of the running relay and a energized delay relay. The compressor starting circuit is connected in series with a second contact of the start button, a stop button, a normally open switch of the protection relay, and a start relay. A first normally open switch of the start relay is connected in parallel to the second contact of the start button. The compressor running circuit is connected in series with a second normally open switch of the start relay, a normally open switch of the energized delay relay, a normally open switch of the low-pressure delay relay, and a compressor running contactor. A first normally open switch of the compressor running contactor is connected in parallel to the normally open switch of the energized delay relay. The cooling fan running circuit is connected in series with a second normally open switch of the compressor running contactor, a high-pressure control switch for the compressor exhaust port, and a fan running contactor.

2. The control circuit for a marine air-cooled air conditioning compressor according to claim 1, characterized in that: A power protection switch is also connected in series in the protection circuit. The contacts of the power protection switch are in the protection circuit, and the coil of the power protection switch is in the three-phase main circuit of the control power supply.

3. The control circuit for a marine air-cooled air conditioning compressor according to claim 2, characterized in that: It also includes a fault test circuit, which includes short-circuit circuits with short-circuit switches connected in parallel to the compressor discharge port fault protection switch, power protection switch, oil level protection switch, over-temperature protection switch, compressor overload protection switch, and cooling fan overload switch.

4. The control circuit for a marine air-cooled air conditioning compressor according to claim 3, characterized in that: A protection indicator light is connected in parallel to the protection relay.

5. The control circuit for a marine air-cooled air conditioning compressor according to claim 4, characterized in that: The coil of the over-temperature protection switch is connected in series with the control power supply via the stop button.

6. A control method using the control circuit of a marine air-cooled air conditioning compressor as described in claim 5, characterized in that: Includes the following steps: (1) Circuit power-on: After the second normally closed switch of the running relay of the restart delay circuit is turned on, the energized delay relay is energized. After the delay time, the normally open switch of the energized delay relay of the compressor running circuit is closed, the compressor running contactor is not connected, and the compressor is in the standby state. (2) Button start: Press the start button, the start button jogs to connect the first contact of the start button, the control relay is energized, the first and second normally open switches of the control relay are closed, the oil level de-energization delay relay is energized, the normally open switch of the oil level de-energization delay relay is closed, the first normally open switch of the control relay and the normally open switch of the oil level de-energization delay relay lock the first contact of the start button that was jogged and released, and the control relay is continuously energized; (3) Low pressure control and protection circuit control: The low pressure control switch at the compressor return port detects the pressure at the compressor return port. If the pressure is normal, the low pressure power failure delay relay is activated. The low pressure power failure delay relay is energized, and the normally open switch of the power failure delay relay on the compressor running circuit is closed. When the button is pressed to start, the third normally open switch of the control relay is closed. The power protection switch on the three-phase main circuit of the control power supply is closed when it is normally connected. The compressor exhaust port fault protection switch, over-temperature protection switch, compressor overload protection switch, and cooling fan overload switch on the protection circuit are all connected without fault. The protection relay is energized, and the protection indicator light on the protection relay is normal. (4) Compressor operation control: When the protection relay is energized, the normally open switch of the protection relay is closed, the starting relay is energized, the first and second normally open switches of the starting relay are closed, locking the connection of the compressor starting circuit, and at the same time connecting the compressor operation circuit, the compressor operation contactor is energized, the first and second normally closed switches of the compressor operation contactor are opened, the energized delay relay is de-energized, the normally open switch of the energized delay relay is opened, the normally open switch of the compressor operation contactor is closed, the first normally open switch of the compressor operation contactor is connected, locking the de-energized normally open switch of the energized delay relay, ensuring that the compressor operation contactor remains energized and the compressor operates normally; (5) Cooling fan operation control: The high pressure control switch at the compressor exhaust port detects the compressor exhaust port pressure and keeps it connected. When the second normally open switch of the compressor operation contactor is turned on, the fan operation contactor is energized, and the cooling fan operates normally. (6) Shutdown control: Pressing the stop button will momentarily disconnect the compressor starting circuit, de-energize the starting relay, open the first and second normally open switches of the starting relay, keep the compressor starting circuit and compressor running circuit disconnected, de-energize the compressor running contactor, open the first and second normally open switches of the compressor running contactor, disconnect the cooling fan running circuit, and stop the compressor and cooling fan. (7) Delayed start control: The normally closed switch of the compressor running contactor closes after the machine stops, and the energized delay relay is energized. During the delay time of the energized delay relay, the normally open switch of the energized delay relay on the compressor running circuit does not close. At this time, if the start button is pressed, the compressor running contactor will never be energized, and the compressor will not run. After the delay period, the normally open switch of the power-on delay relay remains closed. After that, pressing the start button will cause the compressor to start again after the delay protection period. (8) Oil level protection control: When the compressor is running, the normally closed switch of the compressor running contactor is opened. When the oil level is not sufficient or too high, the oil level switch is disconnected and the oil level de-energization delay relay is de-energized. The normally open switch of the oil level de-energization delay relay is opened and closed, and the delay control relay is de-energized, delaying the shutdown of the compressor and cooling fan. (9) Fault protection control: If any of the compressor discharge port fault protection switch, power supply protection switch, over-temperature protection switch, compressor overload protection switch, or cooling fan overload switch detects the corresponding compressor discharge port fault, power supply fault, compressor over-temperature, compressor overload, or cooling fan overload signal, the protection circuit will be disconnected, the protection relay will be de-energized, the normally open switch of the protection relay will open and close, the compressor starting circuit will be de-energized, and the starting relay will be de-energized, thereby controlling the compressor running circuit and cooling fan running circuit to de-energize, the compressor running contactor and cooling fan running contactor to de-energize, and the compressor and cooling fan will be shut down for protection. (10) Fault detection: Press the multiple short-circuit switches on the short-circuit circuit respectively, and short-circuit the compressor exhaust port fault protection switch, power protection switch, oil level protection switch, over-temperature protection switch, compressor overload protection switch and cooling fan overload switch in sequence to check whether the protection switch of the corresponding short-circuit switch is disconnected, thereby detecting the fault point corresponding to the protection switch.

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