CN105987551A - Electronic expansion valve opening degree control method and system for preventing frosting deterioration of air conditioner - Google Patents

Abstract

The invention relates to an electronic expansion valve opening degree control method and system for preventing frosting deterioration of an air conditioner. According to the control method, if T<d> is smaller than T<d target>, an electronic expansion valve is closed; if T<d> is larger than T<d target>, the electronic expansion valve is opened; if T<d> is equal to T<d target>, the electronic expansion valve is forbidden to be operated; and when it is detected that T<d> is equal to T<d target> within continuous time t<1>, whether an outdoor heat exchanger begins to frost or not is detected, and if yes, closing operation on the electronic expansion valve is forbidden. The electronic expansion valve opening degree control method suitable for the electronic expansion valve under the frosting condition is made according to the temperature change rules after the outdoor heat exchanger of the air conditioner frosts, frosting deterioration of the air conditioner under the condition can be effectively prevented, the rate of decay of the heating amount of the air conditioner is decreased, and the comfort performance of the air conditioner is improved.

Description

The electronic expansion valve opening control method of air-conditioning antifrost deterioration and system

Technical field

The invention belongs to the electronic expansion valve opening control technical field that air-conditioning antifrost deteriorates, specifically, relate to electronic expansion valve opening control method and system that a kind of air-conditioning antifrost deteriorates.

Background technology

Convertible frequency air-conditioner typically uses target exhaust temperature to be controlled the aperture of electric expansion valve as controlling parameter at present, concrete control method is: by indoor environment temperature and the temperature difference of design temperature, indoor machine wind shelves and outdoor environment temperature determine the target frequency of compressor, again by the corresponding corresponding compressor target exhaust temperature of target frequency, thus the aperture regulation of electric expansion valve is carried out according to the difference of current exhaust gas temperature and target exhaust temperature, being finally reached target exhaust temperature, referred to as aerofluxus adjusts valve to control.

Air-conditioning heating operation at low ambient temperatures, when outdoor heat exchanger surface temperature is in subzero, and during less than surrounding air dew point temperature, there will be frost, the heat exchange of system low-voltage side is deteriorated, and pressure reduces, and then has influence on high pressure, causing high pressure also to reduce, corresponding compressor exhaust temperature also reduces.Current aerofluxus adjusts valve to control, in order to maintain target exhaust temperature, the aperture of electric expansion valve can be turned down further, making low-pressure side flow-reduction, cause low pressure lower, heat exchanger surface temperature is lower, frosting is more serious, so vicious cycle, accelerates the decay of air-conditioning heating ability, affects comfortableness.

Summary of the invention

It is an object of the invention to provide the electronic expansion valve opening control method that a kind of air-conditioning antifrost deteriorates, solve existing aerofluxus and adjust valve to control, when outdoor heat exchanger of air conditioner frosting, to continue to turn down electric expansion valve, cause what frosting deteriorated technical problem.

For solving above-mentioned technical problem, the present invention is achieved by the following technical solutions:

The electronic expansion valve opening control method that a kind of air-conditioning antifrost deteriorates, described method comprises the steps:

(1) air-conditioning heating runs, in real time detection compressor exhaust temperature T_d;

(2) if T_d＜ T_{d Target}, carry out electric expansion valve closing valve operation；If T_d＞ T_{d Target}, electric expansion valve is carried out valve opening operation；If T_d=T_{d Target}, forbid electric expansion valve is operated, wherein, T_{d Target}Target exhaust temperature for compressor correspondence target frequency；

(3) if continuous t₁T is detected in time_d=T_{d Target}, enter step (4)；

(4) detection outdoor environment temperature T_{Outer shroud}, outdoor coil temperature T_eIf, t continuously₂Time detecting is to outdoor coil temperature T_e≤T_{Outer shroud}-A, electric expansion valve forbid close valve operation, wherein, A is constant.

Preferably, described time t₁And t₂For the arbitrary value of 2-5min, described A is the arbitrary value of 5-8 DEG C.

Design based on the electronic expansion valve opening control method that above-mentioned air-conditioning antifrost deteriorates, the invention allows for a kind of control system, including:

Timing unit, is used for recording time t₁、t₂, and transmit to control unit；

Temperature detecting unit, is used for detecting compressor exhaust temperature T_d, outdoor environment temperature T_{Outer shroud}, outdoor coil temperature T_e, and transmit to control unit；

Control unit, for continuous t₁T is detected in time_d=T_{d Target}, continuous t₂Time detecting is to outdoor coil temperature T_e≤T_{Outer shroud}-A, controls electric expansion valve and forbids turning down.

Compared with prior art, advantages of the present invention and good effect be: the present invention is directed to the temperature changing regularity after outdoor heat exchanger of air conditioner frosting, formulate the aperture control method of the electric expansion valve being applicable under frozen condition, can effectively prevent air-conditioning frosting under this operating mode from deteriorating, slow down the rate of decay of air-conditioning heating amount, promote the comfortableness of air-conditioning.

After reading in conjunction with the accompanying the detailed description of embodiment of the present invention, the other features and advantages of the invention will become clearer from.

Accompanying drawing explanation

Fig. 1 is the flow chart of the specific embodiment of the invention.

Fig. 2 is the air-conditioning heating amount attenuation process schematic diagram of prior art control method and specific embodiment of the invention control method.

Fig. 3 is the theory diagram of the specific embodiment of the invention.

Detailed description of the invention

Below in conjunction with the accompanying drawings the detailed description of the invention of the present invention is described in detail.

When air-conditioning heating runs, if outdoor heat exchanger frosting, compressor exhaust temperature can be caused to reduce, when compressor exhaust temperature is less than target exhaust temperature, carry out electric expansion valve closing valve operation, in order to maintain target exhaust temperature, prior art can turn down the aperture of electric expansion valve further so that low-pressure side flow-reduction, cause low pressure lower, heat exchanger surface temperature is lower, and frosting is more serious, causes air-conditioning heating amount rapid decay.The present invention, by controlling the aperture of electric expansion valve, slow down the speed of air-conditioning heating amount decay, improves comfortableness during above-mentioned operating mode.

Concrete, as it is shown in figure 1, the electronic expansion valve opening control method that the present embodiment air-conditioning antifrost deteriorates comprises the steps:

S1, air-conditioning are opened, and enter heating operation mode.

S2, in real time detection compressor exhaust temperature T_d；If T_d＜ T_{d Target}, carry out electric expansion valve closing valve operation；If T_d＞ T_{d Target}, electric expansion valve is carried out valve opening operation；If T_d=T_{d Target}, forbid electric expansion valve is operated, wherein, T_{d Target}Target exhaust temperature for compressor correspondence target frequency.

S3, in order to make system be rapidly achieved to heat optimal stable performance state, then carry out the control of antifrost deterioration, need continuous t₁T is detected in time_d=T_{d Target}, enter step S4.

S4, detection outdoor environment temperature T_{Outer shroud}, outdoor coil temperature T_eIf, t continuously₂Time detecting is to outdoor coil temperature T_e≤T_{Outer shroud}-A, electric expansion valve forbid close valve operation, wherein, A is constant.Time t₁And t₂For the arbitrary value of 2-5min, A is the arbitrary value of 5-8 DEG C.

As shown in Figure 2, prior art control method and the air-conditioning heating amount attenuation process schematic diagram of the specific embodiment of the invention control method when starting frosting for air-conditioning, as can be seen from Figure 2, the air-conditioning heating amount rate of decay of control method of the present invention is significantly lower than prior art control method, can be effectively improved comfortableness.

The design of defrosting control method when protecting based on the frequent high temperature-proof of above-mentioned air-conditioning heating; the present embodiment also proposed the control system of the electronic expansion valve opening control method that a kind of air-conditioning antifrost deteriorates, including timing unit, temperature detecting unit and control unit.Control unit compares with pre-conditioned according to time parameter, the temperature parameter of temperature detecting unit detection of timing unit record, when meeting pre-conditioned, controls the state of electric expansion valve.

Concrete, as it is shown on figure 3, the defrosting control system during protection of the present embodiment air-conditioning heating frequent high temperature-proof includes:

Timing unit, is used for recording time t₁、t₂, and transmit to control unit；

Temperature detecting unit, including the temperature sensor being installed on exhaust outlet of compressor, is used for detecting delivery temperature T_d；It is installed on the outdoor environment temperature sensor of outdoor, is used for detecting outdoor environment temperature T_{Outer shroud}；It is installed on the temperature sensor on outdoor heat exchanger coil pipe, is used for detecting outdoor coil temperature T_e, and transmit to control unit；

Control unit, for receiving the clock signal that timing unit sends, the temperature signal of temperature detecting unit detection.Obtain T_{d Target}, T_{d Target}Target exhaust temperature for compressor correspondence target frequency.If T_d＜ T_{d Target}, carry out electric expansion valve closing valve operation；If T_d＞ T_{d Target}, electric expansion valve is carried out valve opening operation；If T_d=T_{d Target}, forbid electric expansion valve is operated.If t continuously₁T is detected in time_d=T_{d Target}, detect outdoor environment temperature T_{Outer shroud}, outdoor coil temperature T_eIf, t continuously₂Time detecting is to outdoor coil temperature T_e≤T_{Outer shroud}-A, electric expansion valve forbid close valve operation, wherein, A is constant.

Last it is noted that above example is only in order to illustrate technical scheme, it is not intended to limit；Although the present invention being described in detail with reference to previous embodiment, it will be understood by those within the art that: the technical scheme described in foregoing embodiments still can be modified by it, or wherein portion of techniques feature is carried out equivalent；And these amendments or replacement, do not make the essence of appropriate technical solution depart from the spirit and scope of various embodiments of the present invention technical scheme.

Claims (3)

1. the electronic expansion valve opening control method that an air-conditioning antifrost deteriorates, it is characterised in that described method comprises the steps:

Air-conditioning heating runs, in real time detection compressor exhaust temperature T_d;

If T_d＜ T_{d Target}, carry out electric expansion valve closing valve operation；If T_d＞ T_{d Target}, electric expansion valve is carried out valve opening operation；If T_d=T_{d Target}, forbid electric expansion valve is operated, wherein, T_{d Target}Target exhaust temperature for compressor correspondence target frequency；

If t continuously₁T is detected in time_d=T_{d Target}, enter step (4)；

Detection outdoor environment temperature T_{Outer shroud}, outdoor coil temperature T_eIf, t continuously₂Time detecting is to outdoor coil temperature T_e≤T_{Outer shroud}-A, electric expansion valve forbid close valve operation, wherein, A is constant.

The electronic expansion valve opening control method that air-conditioning antifrost the most according to claim 1 deteriorates, it is characterised in that described time t₁And t₂For the arbitrary value of 2-5min, described A is the arbitrary value of 5-8 DEG C.

3. the control system of the electronic expansion valve opening control method deteriorated based on the air-conditioning antifrost described in claim 1-2 any one, it is characterised in that described control system includes:

Timing unit, is used for recording time t₁、t₂, and transmit to control unit；

Temperature detecting unit, is used for detecting compressor exhaust temperature T_d, outdoor environment temperature T_{Outer shroud}, outdoor coil temperature T_e, and transmit to control unit；

Control unit, for continuous t₁T is detected in time_d=T_{d Target}, continuous t₂Time detecting is to outdoor coil temperature T_e≤T_{Outer shroud}-A, controls electric expansion valve and forbids turning down.