A heat pump type electric vehicle air conditioner defrosting online detection and control method

Abstract

The invention discloses an on-line defrosting detection and control system for a heat pump type electric automobile air conditioner. The on-line defrosting detection and control system comprises a processor, and a temperature sensor, a camera, a humiture sensor I, an air speed sensor and a humiture sensor II which are respectively connected with the processor, wherein the temperature sensor is arranged on the surface of an inlet pipeline of a heat pump working condition heat exchanger of an automobile outside heat exchanger of the heat pump type electric automobile air conditioner; the camera is arranged at the bottommost part of a heat exchanger fin on the inlet side of the automobile outside heat exchanger; the humiture I is arranged at the middle part of an air inlet grating of the automobile outside heat exchanger; the air speed sensor and the humiture sensor II are arranged behind a fan at an air outlet of the automobile outside heat exchanger. According to the system and the method which are disclosed by the invention, a frosting condition and a defrosting condition of the automobile outside heat exchanger under a heating working condition can be accurately judged, and the problems of mis-defrosting such as defrosting under a condition of no frost, no defrosting under a condition of frosts, incomplete defrosting, non-stopping under a condition that the frosts are completely cleared are solved; the defrosting loss of a heat pump air conditioning system is reduced, and the heating performance of the heat pump air conditioning system is improved.

Description

technical field [0001] The invention relates to the technical field of air source heat pump applications, in particular to a heat pump type electric vehicle air conditioner defrosting online detection and control system and method. Background technique [0002] When the air source heat pump air conditioner is heating in winter, the outdoor heat exchanger is easy to frost. When the frost layer reaches a certain height, it must be defrosted. The method of defrosting determines the efficiency of defrosting, and the detection of frost layer thickness and The defrosting control strategy determines the heating efficiency of the whole unit. At present, scholars at home and abroad have done a lot of theoretical and experimental research on frost thickness detection and defrosting control strategies. The main methods are as follows: [0003] 1) Timing control method: the method adopted in the early days. When setting the defrosting time, the worst environmental conditions are often...

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Problems solved by technology

[0007] 5) Self-correcting defrosting control method: This defrosting method involves many factors, and the detection and self-control are complicated

[0008] 6) Frost layer sensor method: The frosting of the evaporator can be directly detected by photoelectric or capacitance detectors. This method is simple in principle, but involves high-gain signal amplifiers and expensive sensors. It is feasible as an experimental method, and the actual application economy is too poor

At present, some scholars have proposed some direct detection methods of frost layer thickness, and carried out experiments in the laboratory, such as using microscopes, micrometers, etc. to measure the frost layer thickness, and using the global image of the heat exchanger to measure the overall frosting area of ​​the heat exchanger , but the above methods can only be used in laboratories or fixed places, and cannot be used in actual operating environments, especially in cars with small space for heat exchangers and sports.

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