CN102116549B - Method for defrosting of direct current variable frequency heat pump air conditioner - Google Patents

Abstract

A method for defrosting a DC frequency conversion heat pump air conditioner, characterized in that: when the air conditioner is running in the heating mode, when the defrosting condition is reached, the defrosting process starts, at this time, the four-way valve does not change direction, and the compressor operates at 160Hz~ 180Hz operation, the outdoor electronic expansion valve is fully open, the outdoor fan is fully open, the indoor fan is running at a low windshield, and when the defrosting stop condition is reached, the defrosting process is exited; the opening degree of the electronic expansion valve fully open is greater than 450 pulses; Compared with the existing method, the present invention has the characteristics of shorter defrosting time, lower energy consumption, smaller indoor temperature fluctuation and no influence on the service life of the four-way valve and the compressor.

Description

Method of defrosting DC frequency conversion heat pump air conditioner

Technical field:

The invention relates to the field of air conditioner control, in particular to a defrosting method for a DC frequency conversion heat pump air conditioner.

Background technique:

At present, the defrosting method of household heat pump air conditioners or conventional central heat pump air conditioners (generally referring to air conditioners with a power of 6 hp and below) in winter heating is to use the reversing of the four-way reversing valve to perform hot air defrosting. The method of converting the heater from heating to cooling, and then from cooling to heating, but when defrosting in this defrosting method, the heating needs to be interrupted for a period of time, and the heat loss is relatively large, so that the indoor temperature fluctuates relatively large. It also makes customers complain a lot, and the life of the four-way valve and compressor of the unit will be shortened. Therefore, the defrosting method of the DC frequency conversion heat pump air conditioner in the prior art has the problems of long defrosting time during defrosting, high energy consumption, large indoor temperature fluctuations, and short service life of the four-way valve and compressor.

Invention content:

Aiming at the above problems, the present invention provides a method for defrosting a direct current frequency conversion heat pump air conditioner with shorter defrosting time, lower energy consumption, smaller indoor temperature fluctuations and no influence on the service life of the four-way valve and the compressor.

The technical solution used by the present invention to solve the above problems is to provide a method for defrosting a DC frequency conversion heat pump air conditioner. When the air conditioner is running in the heating mode, when the defrosting condition is reached, the defrosting process starts. Reversing, the compressor runs at 160Hz-180Hz, the outdoor electronic expansion valve is fully open, the outdoor fan is fully open, and the indoor fan is running at a low windshield. When the defrosting stop condition is reached, the defrosting process is exited; the electronic expansion valve is fully open. The opening degree is greater than 450 pulses. The defrosting condition is that when the temperature of the outdoor coil of the air conditioner and the outdoor ambient temperature meet any of the following conditions for 2 minutes in a row, the defrosting process will start immediately; otherwise, it will start after 20 minutes of continuous operation. Defrost process: 1) 5 to 20 minutes after power on for the first time, regardless of the ambient temperature, when Te≤-12°C, enter the defrosting process; 2) If the outdoor ambient temperature Tamb≤0°C, then when Te≤0.8Tamb+ Enter the defrosting process at a°C; 3) If the outdoor ambient temperature Tamb>0°C, then enter the defrosting process when Te≤0.2 Tamb+a°C; 4) If the outdoor ambient temperature sensor fails, when the outdoor coil temperature Te ≤+a℃ to enter the defrosting process; 5) If the outdoor defrosting temperature sensor fails, it will immediately enter the defrosting process when the defrosting interval time (heating time) ends, and the defrosting time is set at 2 to 10 minutes ; The a is an adjustable value; Tamb is the outdoor ambient temperature; Te is the temperature measured by the temperature sensor after throttling.

After adopting the above method, compared with the prior art, in the present invention, the four-way valve does not reversing during defrosting, the compressor operates at 160Hz-180Hz, the outdoor electronic expansion valve is fully opened, the outdoor fan is fully open, and the indoor fan is at low temperature. When the windshield is running, when the defrosting stop condition is reached, the defrosting process will exit; the opening of the electronic expansion valve is more than 450 pulses, and the indoor heat exchanger does not need to be converted from heating to cooling, and then from cooling to cooling. It is enough to keep the current state, so there is no need to interrupt the heating, so the defrosting speed is faster, and the defrosting time is shortened by more than half compared with the existing technology; secondly, the indoor coil maintains a higher temperature, and the indoor air supply temperature is lowered. It is small, the room temperature reduction caused by defrosting is reduced from the original 6°C to 2°C, and the energy saving is more than 25% during operation; moreover, the four-way valve does not operate, and the operating environment of the compressor has not changed. After the above defrosting conditions are judged under the original conditions, the number of defrosting is reduced, so the defrosting conditions of the present invention are more reasonable, and the energy saving effect is obvious, and the energy consumption is lower. Therefore, the present invention has the characteristics of short defrosting time, low energy consumption, small indoor temperature fluctuation and no influence on the service life of the four-way valve and the compressor.

As a further improvement, the defrosting stop condition is any of the following conditions: 1) Te≥b°C or defrosting time≥c minutes, then immediately exit the defrosting process, the b is an adjustable value, and the c is an adjustable value; 2) When the outdoor coil temperature sensor fails, the defrosting time is set at 2 to 10 minutes; after 2 to 10 minutes of defrosting, immediately exit the defrosting process, then under the above defrosting stop conditions In the defrosting process, the defrosting process can be stopped in time under the premise of effectively achieving the defrosting effect, so that the energy consumption of the present invention is lower.

The described power-on is 10 minutes.

The described defrosting time is set at 5 minutes.

Detailed ways:

Below in conjunction with specific embodiment, the present invention is made a pulse description:

Example 1

The implementation of the method for controlling the defrosting mode of the electronic expansion valve of the DC inverter air conditioner of the present invention will be described in detail below in conjunction with the above-mentioned DC inverter multi-connected central air-conditioning system:

When the air conditioner is running in the heating mode, when the defrosting conditions are met, the defrosting process starts. At this time, the electric heating device is turned on, the four-way valve does not change direction, the compressor runs at 180Hz, and the outdoor electronic expansion valve is fully opened. The outdoor fan is fully turned on, and the indoor fan is running at a low windshield. When the defrosting stop condition is reached, the defrosting process is exited; the opening of the electronic expansion valve fully opened is greater than 450 pulses (1000 pulses in this example), and the electronic expansion valve The opening range of the air conditioner is 0 pulse to 1000 pulses; other operations are the same as the operation mode of the air conditioner in the prior art; the control of each device is an existing conventional control method.

The defrosting condition mentioned is that when the temperature of the outdoor coil of the air conditioner and the outdoor ambient temperature meet any of the following conditions for 2 consecutive minutes, the defrosting process will start immediately, otherwise the defrosting process can only be started after 20 minutes of continuous operation:

1) 5 minutes after power on for the first time, no matter what the ambient temperature is, when Te≤-12℃, it will enter the defrosting process;

2) If the outdoor ambient temperature Tamb≤0°C, enter the defrosting process when Te≤0.8Tamb+a°C;

3) If the outdoor ambient temperature Tamb>0°C, enter the defrosting process when Te≤0.2Tamb+a°C;

4) If the outdoor ambient temperature sensor fails, enter the defrosting process when the outdoor coil temperature Te≤+a℃;

5) If the outdoor defrosting temperature sensor fails, it will enter the defrosting process immediately when the defrosting interval time (also called heating time) ends, and the defrosting time is set at 2 minutes;

The above-mentioned a is an adjustable value, and the default value is -10; Tamb is the outdoor ambient temperature; Te is the temperature measured by the temperature sensor after throttling.

The defrosting stop condition is any of the following conditions:

1) If Te≥b°C or defrosting time≥c minutes, the defrosting process will be exited immediately, b mentioned above is an adjustable value, and the default value of b is 12, and c mentioned above is an adjustable value, and the default value of c 10;

2) When the outdoor coil temperature sensor fails, the defrosting time is set at 2 minutes; after 2 minutes of defrosting, exit the defrosting process immediately.

Example 2

When the air conditioner is running in the heating mode, when the defrosting conditions are met, the defrosting process starts. At this time, the electric heating device is turned on, the four-way valve does not change direction, the compressor runs at 170Hz, and the outdoor electronic expansion valve is fully opened. The outdoor fan is fully turned on, and the indoor fan is running at a low windshield. When the defrosting stop condition is reached, the defrosting process is exited; the opening of the electronic expansion valve fully opened is greater than 450 pulses (1200 pulses in this example), and the electronic expansion valve The opening range is 0 pulse to 1200 pulse.

The defrosting condition mentioned is that when the temperature of the outdoor coil of the air conditioner and the outdoor ambient temperature meet any of the following conditions for 2 consecutive minutes, the defrosting process will start immediately, otherwise the defrosting process can only be started after 20 minutes of continuous operation:

1) 10 minutes after the first power-on, no matter what the ambient temperature is, when Te≤-12°C, it will enter the defrosting process;

2) If the outdoor ambient temperature Tamb≤0°C, enter the defrosting process when Te≤0.8Tamb+a°C;

3) If the outdoor ambient temperature Tamb>0°C, enter the defrosting process when Te≤0.2Tamb+a°C;

4) If the outdoor ambient temperature sensor fails, enter the defrosting process when the outdoor coil temperature Te≤+a℃;

5) If the outdoor defrosting temperature sensor fails, it will enter the defrosting process immediately when the defrosting interval time (also called heating time) ends, and the defrosting time is set at 5 minutes;

The above-mentioned a is an adjustable value, and the default value is -10; Tamb is the outdoor ambient temperature; Te is the temperature measured by the temperature sensor after throttling.

The defrosting stop condition is any of the following conditions:

1) If Te≥b°C or defrosting time≥c minutes, the defrosting process will be exited immediately, b mentioned above is an adjustable value, and the default value of b is 12, and c mentioned above is an adjustable value, and the default value of c 10;

2) When the temperature sensor of the outdoor coil fails, the defrosting time is set at 5 minutes; after 5 minutes of defrosting, exit the defrosting process immediately.

Example 3

When the air conditioner is running in the heating mode, when the defrosting conditions are met, the defrosting process starts. At this time, the electric heating device is turned on, the four-way valve does not change direction, the compressor runs at 160Hz, and the outdoor electronic expansion valve is fully opened. The outdoor fan is fully turned on, and the indoor fan is running at a low windshield. When the defrosting stop condition is reached, the defrosting process is exited; the opening degree of the electronic expansion valve fully opened is greater than 450 pulses (900 pulses in this example), and the electronic expansion valve The opening range is 0 pulse to 900 pulse.

The defrosting condition mentioned is that when the temperature of the outdoor coil of the air conditioner and the outdoor ambient temperature meet any of the following conditions for 2 consecutive minutes, the defrosting process will start immediately, otherwise the defrosting process can only be started after 20 minutes of continuous operation:

1) 20 minutes after power on for the first time, no matter what the ambient temperature is, when Te≤-12℃, it will enter the defrosting process;

2) If the outdoor ambient temperature Tamb≤0°C, enter the defrosting process when Te≤0.8Tamb+a°C;

3) If the outdoor ambient temperature Tamb>0°C, enter the defrosting process when Te≤0.2Tamb+a°C;

4) If the outdoor ambient temperature sensor fails, enter the defrosting process when the outdoor coil temperature Te≤+a℃;

5) If the outdoor defrosting temperature sensor fails, it will enter the defrosting process immediately when the defrosting interval time (also called heating time) ends, and the defrosting time is set at 10 minutes;

The above-mentioned a is an adjustable value, and the default value is -10; Tamb is the outdoor ambient temperature; Te is the temperature measured by the temperature sensor after throttling.

The defrosting stop condition is any of the following conditions:

1) If Te≥b°C or defrosting time≥c minutes, the defrosting process will be exited immediately, b mentioned above is an adjustable value, and the default value of b is 12, and c mentioned above is an adjustable value, and the default value of c 10:

2) When the temperature sensor of the outdoor coil fails, the defrosting time is set at 10 minutes; after 10 minutes of defrosting, exit the defrosting process immediately.

The above embodiments are only preferred embodiments of the present invention, and the present invention is not limited to the above embodiments and also allows other structural changes, such as: the compressor operates at 165Hz, 168Hz, 175Hz or 178Hz, etc., all in the independent claims of the present invention Changes within the range all belong to the protection scope of the present invention.

Claims (4)

1. the method for a DC frequency-changing heat pump air conditioner defrosting is characterized in that: when air-conditioning moves under heating mode, when reaching the defrosting condition; Begin to carry out defrost process, this moment, cross valve did not commutate, and compressor is with 160Hz～180Hz running; Outdoor electric expansion valve standard-sized sheet, the outdoor fan standard-sized sheet, indoor fan turns round at low windscreen; After reaching the defrosting stop condition, withdraw from defrost process; The aperture of described electric expansion valve standard-sized sheet is greater than 450 pulses; Described defrosting condition gets into defrost process during for arbitrary condition below the outdoor coil pipe used temperature of air-conditioning and outdoor environment temperature satisfied in continuous 2 minutes immediately, otherwise after continuous the running 20 minutes, could get into defrost process:

1) powered on first 5～20 minutes after, no matter environment temperature is how,, get into defrost process when Te≤-12 ℃;

2) if outdoor environment temperature Tamb≤0 ℃, then entering defrost process when Te≤0.8Tamb+a ℃;

3) if outdoor environment temperature Tamb＞0 ℃, then entering defrost process when Te≤0.2 Tamb+a ℃;

4) if the outdoor environment temperature sensor fault, then when outdoor coil pipe used temperature T e≤+ entering defrost process during a ℃;

5) if outdoor defrosting temperature sensor fault then gets into defrost process immediately when the defrost interval time finishes, be decided to be 2～10 minute in the defrosting time this moment;

Described a is the tunable integers value; Tamb is an outdoor environment temperature; Te is the temperature of temperature sensor measurement after the throttling.

2. the method for DC frequency-changing heat pump air conditioner defrosting according to claim 1, it is characterized in that: described powering on is 10 minutes.

3. the method for DC frequency-changing heat pump air conditioner according to claim 1 defrosting is characterized in that: described defrosting stop condition be below arbitrary condition:

1) Te >=b ℃ or defrosting time >=c minute, then withdraw from defrost process immediately, described b is the tunable integers value, described c is the tunable integers value;

2) when outdoor coil pipe used temperature sensor fault, be decided to be 2～10 minutes in the defrosting time; After defrosting is carried out 2～10 minutes, withdraw from defrost process immediately.

4. according to the method for claim 1 or 3 described DC frequency-changing heat pump air conditioner defrostings, it is characterized in that: be decided to be 5 minutes in the described defrosting time.