CN106152382B - A kind of control method and system for preventing frequency of air condition compressor to fluctuate - Google Patents

Abstract

The present invention relates to a kind of control methods and system for preventing frequency of air condition compressor to fluctuate, and run in air-conditioning heating, real-time detection indoor unit coil temperature T_k;If continuous n times detect T_K=T_{High temperature-proof frequency reducing}, and T_K=T_{High temperature-proof frequency reducing}Cumulative time t₁≥t_Setting；The target frequency of compressor is reduced into F.The present invention when detecting indoor unit coil temperature frequent fluctuation, to high temperature-proof protection in compressor target frequency carry out gradually frequency reducing correct, until compressor can the stable operation under the target frequency, guarantee the using effect of air-conditioning.

Description

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

Technical field

The invention belongs to frequency of air condition compressor control technology fields, specifically, be related to one kind prevent it is air conditioner compressed The control method and system of unit frequency fluctuation.

Background technique

System when convertible frequency air-conditioner generallys use indoor heat exchanger coil temperature (internal pipe temperature) as control air-conditioning heating at present The foundation of high pressure, specific way is: according to the hot physical property table of refrigerant, finding the corresponding saturation temperature of refrigerant saturation pressure, is arranged Prevention & protection raising frequency is kept, slow to drop, and the fast internal pipe temperature dropped and shut down controls compressor operating frequency according to internal pipe temperature, system High voltage control improves operation of air conditioner reliability in reasonable range, referred to as the protection of heating high temperature-proof.

In actual test, such control mode is had the following problems:

Since temperature sensor is not directly to contact with refrigerant, and be inserted into spot-welded together with heat exchanger elbow In copper sleeve, there are thermal contact resistances, and when refrigerant temperature changes, sensor detects temperature and there is lag and jump.

As shown in Figure 1, with maximum heating condition, interior 27/-, for outer 24/18, actual test discovery, when indoor unit is entered the wind It is obstructed (filter screen or heat exchanger fin are dirty stifled), inside pressure increases, and sensor detection internal pipe temperature reaches compressor frequency reducing temperature T_{High temperature-proof frequency reducing}, compressor starts protect frequency reducing, and compressor frequency gradually reduces, and refrigerant (thermocouple detection) temperature is from T_{High temperature-proof frequency reducing}Gradually It is reduced to T_{High temperature-proof raising frequency}, and sensor detection temperature then maintains T_{High temperature-proof frequency reducing}, sensor detects temperature from T later_{High temperature-proof raising frequency}Directly jump Change to T_{High temperature-proof frequency reducing}, compressor enters the prevention & protection raising frequency stage, starts to protect raising frequency operation to target frequency；

Raising frequency process sensor detection temperature lags refrigerant (thermocouple detection) temperature 1-2 degree always, and compressor reaches mesh The internal pipe temperature at mark frequency moment reaches T_{High temperature-proof is kept}, it is maintained at target frequency, but since not to be suitable for interior machine dirty stifled for current frequency Situation, internal pipe temperature continue to increase, and in order to realize that high temperature-proof is protected, compressor needs start to repeat above-mentioned frequency reducing movement, caused by As a result, air-conditioning can not be run under the operating condition with stable frequency, but fluctuated, is caused: 1 up and down with certain frequency amplitude Air conditioning exhausting temperature fluctuation influences user's comfort；2 outer machine noise fluctuations, influence user's sense of hearing；3 system longtime runnings exist In the critical value of high pressure, air-conditioning reliability is influenced.

Summary of the invention

The purpose of the present invention is to provide a kind of control methods for preventing frequency of air condition compressor to fluctuate, and solve existing room When interior machine air inlet is obstructed the technical issues of compressor frequency frequent fluctuation.

In order to solve the above technical problems, the present invention is achieved by the following scheme:

A kind of control method for preventing frequency of air condition compressor to fluctuate, the method are as follows:

Step (1), air-conditioning heating operation, real-time detection indoor unit coil temperature T_k;

Step (2), if continuous n times detect T_K=T_{High temperature-proof frequency reducing}, and T_K=T_{High temperature-proof frequency reducing}Cumulative time t₁≥ t_Setting；

The target frequency of compressor is reduced F by step (3).

Preferably, after step (3) further include:

Step (4) detects T_K, such as continuous t₂Time detects T_K≤T_{High temperature-proof is kept}, compressor by current frequency run, forbid It increases, continues step (2)；Otherwise, continue step (3).

Preferably, the t_SettingFor the arbitrary value of 25-35min, t₂For the arbitrary value of 8-12min, F is any of 1-3Hz Value.

Based on the design of the above-mentioned control method for preventing frequency of air condition compressor to fluctuate, the invention also provides a kind of controls System, comprising:

Timing unit, for recording time t₁、t₂, and it is transmitted to control unit；

Temperature detecting unit, for detecting indoor unit coil temperature T_k, and it is transmitted to control unit；

Control unit, for determining the target frequency of compressor, output control signal, the frequency for controlling compressor reaches mesh Mark frequency.

Compared with prior art, the advantages and positive effects of the present invention are: the present invention is detecting indoor unit coil temperature When frequent fluctuation, gradually frequency reducing is carried out to the compressor target frequency in high temperature-proof protection and is corrected, until compressor can be at this Stable operation under target frequency.

1 avoids air conditioning exhausting temperature fluctuation, influences user's comfort；

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

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

After the detailed description of embodiment of the present invention is read in conjunction with the figure, the other features and advantages of the invention will become more Add clear.

Detailed description of the invention

Fig. 1 is compressor frequency and internal pipe temperature variable condition schematic diagram in background technique.

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

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

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

Specific embodiment

A specific embodiment of the invention is described in detail with reference to the accompanying drawing.

Air-conditioning internal pipe temperature temperature sensor and refrigerant actual temperature are there are larger difference, and sensor detects temperature and refrigerant is real There is lag and jump in border temperature.When air-conditioning heating is run, if indoor unit air inlet is obstructed, internal pipe temperature can occurs repeatedly and cross hot compression Machine needs frequency reducing, due to the lag and jump of temperature sensor detection temperature after frequency reducing, the case where compressor needs frequency reducing, can lead Cause the frequency frequent fluctuation of compressor.The present invention is based on the above problems, proposes a solution, can guarantee this work The stabilization of compressor frequency under condition.

Specifically, as shown in Fig. 2, the control method that the present embodiment prevents frequency of air condition compressor to fluctuate includes following step It is rapid:

S1, air-conditioning heating operation, real-time detection indoor unit coil temperature T_k。

S2, if continuous n times detect T_K=T_{High temperature-proof frequency reducing}, and T_K=T_{High temperature-proof frequency reducing}Cumulative time t₁≥ t_Setting；Illustrate compressor frequency Rate frequent fluctuation.Wherein, n is preferably 3 times, t_SettingFor the arbitrary value of 25-35min.

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

S4 continues to test T_K, such as continuous t₂Time detects T_K≤T_{High temperature-proof is kept}, illustrate that compressor frequency enters steady shape State enters step S5, otherwise, illustrates that compressor frequency does not enter steady state, enters step S3.Wherein, t₂For 8-12min's Arbitrary value.

S5, compressor are run by current frequency, forbid increasing, and continue step S2.

As shown in figure 3,0 arrives t1, compressor frequency rises to F from 0_Target, refrigerant temperature increases from environment temperature and is more than T_{High temperature-proof frequency reducing}, sensor temperature is increased to T from environment temperature_{High temperature-proof frequency reducing}, compressor starts reduction frequency；

T1 to t2, with the reduction of compressor frequency, refrigerant temperature starts to decrease below T_{High temperature-proof raising frequency}, sensor temperature is stagnant Afterwards and jump to T_{High temperature-proof raising frequency}, compressor frequency starts to increase；

T2 to t3, as compressor frequency is increased to F_Target, refrigerant temperature is from lower than T_{High temperature-proof raising frequency}It increases 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 reduction frequency；

T3 to t4, as compressor frequency reduces, refrigerant temperature starts to decrease below T_{High temperature-proof raising frequency}, sensor temperature lag And it jumps to T_{High temperature-proof raising frequency}, compressor frequency starts to increase；

T4 to t5, as compressor frequency is increased to F_Target, refrigerant temperature is from lower than T_{High temperature-proof raising frequency}It increases more than T_{High temperature-proof frequency reducing}, pass Sensor temperature is from T_{High temperature-proof raising frequency}Rise to T_{High temperature-proof frequency reducing}, compressor starts reduction frequency；

T5 to t6, as compressor frequency reduces, refrigerant temperature starts to decrease below T_{High temperature-proof raising frequency}, sensor temperature lag And it jumps to T_{High temperature-proof raising frequency}, compressor frequency starts to increase；

T6 to t7 detects that control parameter meets and imposes a condition, i.e., detects T continuous 3 times_K=T_{High temperature-proof frequency reducing}, and T_K=T_{High temperature-proof frequency reducing} Cumulative time t₁Compressor target frequency is reduced F by >=28min, and compressor frequency rises to F_Target- F, refrigerant temperature is from being lower than T_{High temperature-proof raising frequency}It is increased to T_{High temperature-proof is kept}, sensor temperature is from T_{High temperature-proof raising frequency}It is increased to T_{High temperature-proof is kept}, start stable operation.

Thus, from figure 3, it can be seen that the present embodiment can be good at controlling compressor frequency frequency when indoor unit air inlet is obstructed The problem of numerous fluctuation, can make the frequency of compressor keep stablizing.

Based on the design of the above-mentioned control method for preventing frequency of air condition compressor to fluctuate, the present embodiment also proposed a kind of anti- The only control system of frequency of air condition compressor fluctuation, including timing unit, temperature detecting unit and control unit.Control unit It is compared according to the temperature parameter of the time parameter of timing unit record, temperature detecting unit detection with preset condition, full When sufficient preset condition, the target frequency of compressor, output control signal are redefined, the frequency for controlling compressor reaches target frequency Rate.

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

Timing unit, for recording time t₁、t₂, and it is transmitted to control unit；

Temperature detecting unit, for detecting indoor unit coil temperature T_k, and it is transmitted to control unit；

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

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, rather than its limitations；Although Present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: it still may be used To modify the technical solutions described in the foregoing embodiments or equivalent replacement of some of the technical features； And these are modified or replaceed, technical solution of various embodiments of the present invention that it does not separate the essence of the corresponding technical solution spirit and Range.

Claims (4)

1. a kind of control method for preventing frequency of air condition compressor to fluctuate, which is characterized in that the method are as follows:

Step (1), air-conditioning heating operation, real-time detection indoor unit coil temperature T_k;

Step (2), if continuous n times detect T_K=T_{High temperature-proof frequency reducing}, and T_K=T_{High temperature-proof frequency reducing}Cumulative time t₁≥ t_Setting；

The target frequency of compressor is reduced F by step (3)；

Step (4) detects T_K, such as continuous t₂Time detects T_K≤T_{High temperature-proof is kept}, compressor by current frequency run, forbid rising Height continues step (2)；Otherwise, continue step (3).

2. the control method according to claim 1 for preventing frequency of air condition compressor to fluctuate, which is characterized in that the t_Setting For the arbitrary value of 25-35min, the F is the arbitrary value of 1-3Hz.

3. the control method according to claim 2 for preventing frequency of air condition compressor to fluctuate, which is characterized in that the t₂For The arbitrary value of 8-12min.

4. a kind of based on the control method described in claim 1 for preventing frequency of air condition compressor to fluctuate

Control system, which is characterized in that the control system includes:

Timing unit, for recording time t₁、t₂, and it is transmitted to control unit；

Temperature detecting unit, for detecting indoor unit coil temperature T_k, and it is transmitted to control unit；

Control unit, for determining the target frequency of compressor, output control signal, the frequency for controlling compressor reaches target frequency Rate.