New energy bus heat pump air conditioning unit and control method thereof

Abstract

The invention relates to a new energy bus heat pump air conditioning unit and a control method thereof. The new energy bus heat pump air conditioning unit comprises a compressor, a four-way valve, a condenser, a throttling device and an evaporator, a blocking device used for blocking a refrigerant from flowing back into the compressor from the four-way valve is arranged between the compressor and the condenser, an electromagnetic valve is arranged between the condenser and the throttling device, the electromagnetic valve is connected with a controller circuit; and the controller is used for firstly closing the electromagnetic valve and then controlling the compressor to stop. By controlling the electromagnetic valve and delaying shutdown of the compressor, the process of evacuating the liquid refrigerant in the compressor after the air conditioner is shut down is achieved, most of the refrigerant is isolated in a pipeline between the blocking device and the electromagnetic valve and in the condenser, and therefore it is guaranteed that the interior of the compressor is basically gaseous refrigerant; and a binding post in the compressor is prevented from being submerged by the liquid refrigerant, so that the electrical insulation resistance of the air conditioning unit in a shutdown state is improved.

Description

technical field [0001] The invention relates to an air conditioner, in particular to a bus air conditioner unit and a control method thereof. Background technique [0002] Most of the new energy bus air-conditioning units require that the insulation resistance of the internal circuit of the air conditioner to the ground be greater than 20M ohms, and some car manufacturers even require the resistance to be above 100M ohms. At present, the national standard GB / T21361-2017 stipulates that the insulation resistance of bus air conditioners is above 2MΩ. Most of the time, the insulation resistance of conventional electric bus air conditioners is less than 20MΩ. After testing and research, it is found that the weakest point of insulation resistance is on the compressor. The research also found that the existence of liquid refrigerant in the compressor reduces the insulation resistance between the internal terminal of the compressor and the compressor shell. The test research found...

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Problems solved by technology

[0004] 1. The throttling device adopts a capillary tube. Because the capillary tube cannot be closed, the high and low pressure are connected through, and it is impossible to isolate the refrigerant in high-pressure containers such as condensers.

[0005] 2. The complete elimination of liquid refrigerant in the compressor cannot be realized, resulting in poor insulation performance

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