CN106152382A - A kind of control method preventing frequency of air condition compressor to fluctuate and system - Google Patents

Abstract

The present invention relates to a kind of control method preventing frequency of air condition compressor to fluctuate and system, run at air-conditioning heating, in real time detection indoor set coil temperature T_k;If T being detected n time continuously_K=T_{High temperature-proof frequency reducing}, and T_K=T_{High temperature-proof frequency reducing}Cumulative time t₁≥t_Set；The target frequency of compressor is reduced F.The present invention is when indoor set coil temperature frequent fluctuation being detected, and the compressor target frequency in protecting high temperature-proof carries out gradually frequency reducing correction, until compressor can stable operation under this target frequency, it is ensured that the using effect of air-conditioning.

Description

A kind of control method preventing frequency of air condition compressor to fluctuate and system

Technical field

The invention belongs to frequency of air condition compressor and control technical field, specifically, relate to a kind of control method preventing frequency of air condition compressor to fluctuate and system.

Background technology

Convertible frequency air-conditioner commonly used indoor heat exchanger coil temperature (inner tube temperature) is as the foundation of system high pressure during control air-conditioning heating at present; concrete way is: according to coolant hot physical property table; find the saturation temperature that coolant saturation pressure is corresponding, prevention & protection raising frequency is set, keep; slow fall; fast fall and the inner tube temperature shut down, according to inner tube temperature control compressor operating frequency, control system high pressure in rational scope; improve operation of air conditioner reliability, be referred to as heating high temperature-proof protection.

In reality is tested, this kind of control mode there is problems in that

Owing to temperature sensor is not directly to contact with coolant, and being inserted in the copper sleeve spot-welded together with heat exchanger elbow, there is thermal contact resistance, when refrigerant temperature changes, there is delayed and saltus step in sensor detection temperature.

As it is shown in figure 1, with maximum heating condition, interior 27/-, as a example by outer 24/18, actual test finds, when indoor set air intake is obstructed (drainage screen or heat exchanger fin are dirty stifled), and inside pressure raises, and sensor detection inner tube temperature reaches compressor frequency reducing temperature T_{High temperature-proof frequency reducing}, compressor starts protection frequency reducing, compressor frequency gradually reduces, and coolant (thermocouple detection) temperature is from T_{High temperature-proof frequency reducing}Gradually reduce to T_{High temperature-proof raising frequency}, sensor detection temperature then maintains T_{High temperature-proof frequency reducing}, the temperature of sensor detection afterwards is from T_{High temperature-proof raising frequency}Directly jump to T_{High temperature-proof frequency reducing}, compressor enters the prevention & protection raising frequency stage, starts to run to target frequency protection raising frequency；

The raising frequency process sensor detection the most delayed coolant of temperature (thermocouple detection) temperature 1-2 degree, compressor reaches the inner tube temperature in target frequency moment and reaches T_{High temperature-proof keeps}It is maintained at target frequency; but be not suitable for the dirty stifled situation of interior machine due to ongoing frequency, inner tube temperature continues to raise, in order to realize high temperature-proof protection; compressor needs to start to repeat above-mentioned frequency reducing action; the result caused is, air-conditioning cannot run with stable frequency under this operating mode, but fluctuates up and down with certain frequency amplitude; cause: 1 air conditioning exhausting temperature fluctuation, affect user's comfortableness；2 outer machine noise fluctuation, affect user's sense of hearing；3 system longtime running, in the marginal value at high pressure, affect air-conditioning reliability.

Summary of the invention

It is an object of the invention to provide a kind of control method preventing frequency of air condition compressor to fluctuate, solve the technical problem of compressor frequency frequent fluctuation when existing indoor set air intake is obstructed.

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

A kind of control method preventing frequency of air condition compressor to fluctuate, described method is:

Step (1), air-conditioning heating runs, in real time detection indoor set coil temperature T_k;

Step (2), if detecting T n time continuously_K=T_{High temperature-proof frequency reducing}, and T_K=T_{High temperature-proof frequency reducing}Cumulative time t₁≥ t_Set；

Step (3), reduces F by the target frequency of compressor.

Preferably, also include after step (3):

Step (4), detects T_K, such as continuous t₂Time detecting is to T_K≤T_{High temperature-proof keeps}, compressor is pressed ongoing frequency and is run, and forbids raising, continues step (2)；Otherwise, step (3) is continued.

Preferably, described t_SetFor the arbitrary value of 25-35min, t₂For the arbitrary value of 8-12min, F is the arbitrary value of 1-3Hz.

Design based on the above-mentioned control method preventing frequency of air condition compressor to fluctuate, 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 indoor set coil temperature T_k, and transmit to control unit；

Control unit, for determining the target frequency of compressor, exports control signal, and the frequency controlling compressor reaches target frequency.

Compared with prior art; advantages of the present invention and good effect be: the present invention is when indoor set coil temperature frequent fluctuation being detected; compressor target frequency in protecting high temperature-proof carries out gradually frequency reducing correction, until compressor can stable operation under this target frequency.

1 avoids air conditioning exhausting temperature fluctuation, affects user's comfortableness；

2 avoid outer machine noise fluctuation, affect user's sense of hearing；

3 avoid system longtime running in the marginal value at high pressure, improve air-conditioning reliability.

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 compressor frequency and inner tube temperature variable condition schematic diagram in background technology.

Fig. 2 is the flow chart of the specific embodiment of the invention.

Fig. 3 is compressor frequency and inner tube temperature variable condition schematic diagram in the specific embodiment of the invention.

Fig. 4 is the theory diagram of specific embodiment of the invention control system.

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.

There is larger difference in air-conditioning inner tube temperature temperature sensor and coolant actual temperature, sensor detection temperature exists delayed and saltus step with coolant actual temperature.When air-conditioning heating runs, if indoor set air intake is obstructed, can repeatedly occur that inner tube temperature is crossed thermocompressor and needed frequency reducing, due to the delayed and saltus step of temperature sensor detection temperature after frequency reducing, compressor needs the situation of frequency reducing, can cause the frequency frequent fluctuation of compressor.The present invention is based on the problems referred to above, it is proposed that a solution, it is possible to ensure stablizing of compressor frequency under this operating mode.

Concrete, as in figure 2 it is shown, the control method that the present embodiment prevents frequency of air condition compressor to fluctuate comprises the steps:

S1, air-conditioning heating runs, in real time detection indoor set coil temperature T_k。

S2, if detecting T n time continuously_K=T_{High temperature-proof frequency reducing}, and T_K=T_{High temperature-proof frequency reducing}Cumulative time t₁≥ t_Set；Compressor frequency frequent fluctuation is described.Wherein, n is preferably 3 times, t_SetArbitrary value for 25-35min.

S3, reduces F by the target frequency of compressor.Wherein, F is the arbitrary value of 1-3Hz.

S4, continues detection T_K, such as continuous t₂Time detecting is to T_K≤T_{High temperature-proof keeps}, illustrate that compressor frequency enters plateau, enter step S5, otherwise, illustrate that compressor frequency is introduced into plateau, enter step S3.Wherein, t₂Arbitrary value for 8-12min.

S5, compressor are pressed ongoing frequency and are run, and forbid raising, continue step S2.

As it is shown on figure 3,0 to t1, compressor frequency rises to F from 0_Target, refrigerant temperature raises from ambient temperature and more than T_{High temperature-proof frequency reducing}, sensor temperature is increased to T from ambient temperature_{High temperature-proof frequency reducing}, compressor starts reduces frequency；

T1 to t2, along with the reduction of compressor frequency, refrigerant temperature starts to decrease below T_{High temperature-proof raising frequency}, sensor temperature is delayed and saltus step is to T_{High temperature-proof raising frequency}, compressor frequency starts to raise；

T2 to t3, along with compressor frequency is increased to F_Target, refrigerant temperature is from less than T_{High temperature-proof raising frequency}Raise and more than T_{High temperature-proof frequency reducing}, sensor temperature is from T_{High temperature-proof raising frequency}Rise to T_{High temperature-proof frequency reducing}, compressor starts reduces frequency；

T3 to t4, along with compressor frequency reduces, refrigerant temperature starts to decrease below T_{High temperature-proof raising frequency}, sensor temperature is delayed and saltus step is to T_{High temperature-proof raising frequency}, compressor frequency starts to raise；

T4 to t5, along with compressor frequency is increased to F_Target, refrigerant temperature is from less than T_{High temperature-proof raising frequency}Increase to over T_{High temperature-proof frequency reducing}, sensor temperature is from T_{High temperature-proof raising frequency}Rise to T_{High temperature-proof frequency reducing}, compressor starts reduces frequency；

T5 to t6, along with compressor frequency reduces, refrigerant temperature starts to decrease below T_{High temperature-proof raising frequency}, sensor temperature is delayed and saltus step is to T_{High temperature-proof raising frequency}, compressor frequency starts to raise；

T6 to t7, detects that control parameter meets and imposes a condition, T detected the most continuous 3 times_K=T_{High temperature-proof frequency reducing}, and T_K=T_{High temperature-proof frequency reducing}Cumulative time t₁>=28min, reduces F by compressor target frequency, and compressor frequency rises to F_Target-F, refrigerant temperature is from less than T_{High temperature-proof raising frequency}It is increased to T_{High temperature-proof keeps}, sensor temperature is from T_{High temperature-proof raising frequency}It is increased to T_{High temperature-proof keeps}, start stable operation.

Thus, from figure 3, it can be seen that the present embodiment can be good at controlling the problem of compressor frequency frequent fluctuation when indoor set air intake is obstructed, the frequency of compressor can be made to keep stable.

Design based on the above-mentioned control method preventing frequency of air condition compressor to fluctuate, the present embodiment also proposed a kind of control system preventing frequency of air condition compressor to fluctuate, 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, redefining the target frequency of compressor, export control signal, the frequency controlling compressor reaches target frequency.

Concrete, as shown in Figure 4, the control system that the present embodiment prevents frequency of air condition compressor to fluctuate includes:

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

Temperature detecting unit, is used for detecting indoor set coil temperature T_k, and transmit to control unit；

Control unit, for determining the target frequency of compressor according to above-mentioned control method, and exports control signal, and the frequency controlling compressor reaches target frequency, until compressor operating frequency stable.

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 (5)

1. the control method preventing frequency of air condition compressor to fluctuate, it is characterised in that described method is:

Step (1), air-conditioning heating runs, in real time detection indoor set coil temperature T_k;

Step (2), if detecting T n time continuously_K=T_{High temperature-proof frequency reducing}, and T_K=T_{High temperature-proof frequency reducing}Cumulative time t₁≥ t_Set；

Step (3), reduces F by the target frequency of compressor.

The control method preventing frequency of air condition compressor to fluctuate the most according to claim 1, it is characterised in that also include after described step (3):

Step (4), detects T_K, such as continuous t₂Time detecting is to T_K≤T_{High temperature-proof keeps}, compressor is pressed ongoing frequency and is run, and forbids raising, continues step (2)；Otherwise, step (3) is continued.

The control method preventing frequency of air condition compressor to fluctuate the most according to claim 1 and 2, it is characterised in that described t_SetFor the arbitrary value of 25-35min, described F is the arbitrary value of 1-3Hz.

The control method preventing frequency of air condition compressor to fluctuate the most according to claim 3, it is characterised in that described t₂Arbitrary value for 8-12min.

5. one kind based on the control method preventing frequency of air condition compressor to fluctuate described in claim 1-2 any one

Control system, 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 indoor set coil temperature T_k, and transmit to control unit；

Control unit, for determining the target frequency of compressor, exports control signal, and the frequency controlling compressor reaches target frequency.