CN112212471B - Air conditioning system and compressor control method thereof - Google Patents

Abstract

The invention belongs to the technical field of heat exchange, and particularly relates to an air conditioning system and a compressor control method thereof. The invention aims to solve the problem that the existing air-conditioning system has low energy efficiency under partial working conditions due to the fact that the control mode of the existing air-conditioning system to a plurality of compressors is poor. Therefore, the air conditioning system comprises the fixed-frequency compressor and the variable-frequency compressor which are connected in parallel, so that the air conditioning system can better adapt to different working conditions; the compressor control method of the present invention includes: detecting the actual capacity percentage of the inverter compressor under the condition that the inverter compressor operates alone; when the actual capacity percentage of the variable-frequency compressor reaches a first preset variable-frequency capacity percentage, acquiring the actual load demand percentage of the compressor of the air conditioning system; according to the actual load demand percentage of the compressor of the air conditioning system, the fixed-frequency compressor is selectively operated according to different capacity percentages, so that the air conditioning system can be effectively ensured to be efficiently operated under any working condition.

Description

Air conditioning system and compressor control method thereof

technical field

The invention belongs to the technical field of heat exchange, and in particular relates to an air conditioning system and a compressor control method thereof.

Background technique

With the continuous improvement of people's living standards, people also put forward higher and higher requirements for the living environment. In order to maintain a comfortable ambient temperature, air conditioners have become an indispensable device in people's lives. Generally, an air conditioner includes an indoor unit, an outdoor unit, and a circulation loop for connecting the indoor unit and the outdoor unit. The refrigerant in the air conditioner continuously exchanges heat between the outdoor unit and the indoor unit through the circulation loop, so as to achieve the effect of changing the room temperature. . At the same time, since the refrigerant needs to be realized by the auxiliary function of the compressor in the process of gas-liquid change, the existing air conditioners are equipped with compressors; especially for some large-scale air-conditioning systems, in order to effectively ensure the high efficiency of the air-conditioning system In operation, many air conditioning systems are often equipped with multiple compressors. Existing air-conditioning systems often directly control multiple compressors to run at the same time, but do not control different compressors differently according to the operating conditions of the air-conditioning system, which leads to the lower energy efficiency of existing multi-compressor air-conditioning systems under certain operating conditions. low problem.

Accordingly, there is a need in the art for a new air conditioning system and a compressor control method thereof to solve the above problems.

SUMMARY OF THE INVENTION

In order to solve the above problems in the prior art, that is, in order to solve the problem of low energy efficiency of the air conditioning system under some working conditions due to the poor control mode of the existing air conditioning system for multiple compressors, the present invention provides a A compressor control method for an air-conditioning system, the air-conditioning system comprising a fixed-frequency compressor and a variable-frequency compressor connected in parallel, the compressor control method comprising: detecting the The actual capacity percentage of the variable frequency compressor; when the actual capacity percentage of the variable frequency compressor reaches the first preset frequency conversion capacity percentage, obtain the actual load demand percentage of the compressor of the air conditioning system; Load demand percentage, selectively operating the fixed frequency compressor at different capacity percentages.

In the preferred technical solution of the above-mentioned compressor control method for an air-conditioning system, the step of "selectively operating the fixed-frequency compressor according to different capacity percentages according to the actual load demand percentage of the compressor of the air-conditioning system" Including: comparing the actual compressor load demand percentage of the air conditioning system with a first preset demand percentage; if the compressor actual load demand percentage of the air conditioning system is greater than or equal to the first preset demand percentage, making The fixed frequency compressor operates at a first preset frequency capability percentage.

In the preferred technical solution of the above-mentioned compressor control method for an air-conditioning system, after the step of "operating the fixed-frequency compressor at a first preset frequency capability percentage", the compressor control method further includes: Obtain the actual compressor load demand percentage of the air conditioning system again; compare the compressor actual load demand percentage obtained again with the first preset demand percentage; if the compressor actual load demand percentage of the air conditioning system is actually If the load demand percentage is still greater than or equal to the first preset demand percentage, increase the actual capacity percentage of the fixed-frequency compressor and repeat the above acquisition and comparison steps until the actual capacity percentage of the fixed-frequency compressor is increased to a second preset frequency capacity percentage; and/or if the actual compressor load demand percentage of the air conditioning system is less than the first preset demand percentage, stopping the fixed frequency compressor.

In the above preferred technical solution of the compressor control method for an air conditioning system, after the actual capacity percentage of the fixed-frequency compressor is increased to the second preset frequency capacity percentage, the compressor control method further The method includes: obtaining the actual compressor load demand percentage of the air conditioning system again; comparing the compressor actual load demand percentage obtained again with the first preset demand percentage; The actual compressor load demand percentage of the air conditioning system is still greater than or equal to the first preset demand percentage, increasing the actual capacity percentage of the inverter compressor to a second preset inverter capacity percentage; and/or if all If the actual load demand percentage of the compressor of the air conditioning system is less than the first preset demand percentage, the fixed frequency compressor is stopped.

In the preferred technical solution of the above-mentioned compressor control method for an air conditioning system, after the step of "increasing the actual capacity percentage of the variable frequency compressor to a second preset frequency conversion capacity percentage", the compressor control method further Including: further acquiring the actual load demand percentage of the compressor of the air conditioning system; comparing the further acquired actual compressor load demand percentage of the air conditioning system with a second preset demand percentage; The fixed frequency compressor and the variable frequency compressor work together.

In the above preferred technical solution of the compressor control method for an air-conditioning system, the step of "selectively controlling the fixed-frequency compressor and the variable-frequency compressor to work together according to the comparison result" includes: if the further obtained If the actual compressor load demand percentage of the air-conditioning system is greater than or equal to the second preset demand percentage, the fixed-frequency compressor is operated at full load; and/or if the actual compressor load of the air-conditioning system is further obtained When the demand percentage is less than the second preset demand percentage, both the fixed frequency compressor and the variable frequency compressor are made to operate at the current capacity percentage.

In a preferred technical solution of the above-mentioned compressor control method for an air-conditioning system, the actual load demand percentage of the compressor of the air-conditioning system is equal to the difference between the actual water temperature and the target water temperature of the air-conditioning system divided by the start-up temperature difference of the compressor; and/or the actual capacity percentage of the inverter compressor is equal to the first inverter compressor multiplied by the current evaporating temperature of the inverter compressor plus the second inverter compressor multiplied by the current condensing temperature of the inverter compressor plus the third inverter The coefficient is multiplied by the current operating current of the variable frequency compressor; wherein the first variable frequency coefficient, the second variable frequency coefficient and the third variable frequency coefficient are determined by the model of the variable frequency compressor; and/or the The actual capacity percentage of the fixed frequency compressor is equal to the first fixed frequency coefficient multiplied by the current evaporating temperature of the fixed frequency compressor plus the second fixed frequency coefficient multiplied by the current condensing temperature of the fixed frequency compressor plus the third fixed frequency. The frequency coefficient is multiplied by the current operating current of the fixed-frequency compressor; wherein, the first fixed-frequency coefficient, the second fixed-frequency coefficient and the third fixed-frequency coefficient are determined by the model of the fixed-frequency compressor .

In a preferred technical solution of the above-mentioned compressor control method for an air conditioning system, the first preset frequency conversion capability percentage is 50%.

In a preferred technical solution of the above-mentioned compressor control method for an air conditioning system, the first preset demand percentage is 50%; and/or the first preset frequency capacity percentage is 25%.

In a preferred technical solution of the above-mentioned compressor control method for an air conditioning system, the second preset frequency conversion capability percentage is 75%; and/or the second preset frequency conversion capability percentage is 75%; and/or The second preset frequency capability percentage is 10%.

Those skilled in the art can understand that, in the technical solution of the present invention, the air conditioning system of the present invention includes a fixed-frequency compressor and a variable-frequency compressor connected in parallel, and the compressor control method of the present invention includes: in the variable-frequency compressor Detecting the actual capacity percentage of the variable frequency compressor when the compressor is running alone; when the actual capacity percentage of the variable frequency compressor reaches a first preset frequency conversion capacity percentage, obtain the actual compressor load demand percentage of the air conditioning system ; According to the actual load demand percentage of the compressor of the air conditioning system, selectively make the fixed frequency compressor operate according to different capacity percentages. It should be noted that, due to the high energy efficiency and obvious energy saving effect of variable frequency compressors during partial load operation, the energy efficiency of variable frequency compressors and fixed frequency compressors is almost the same during high load or full load operation; Therefore, the present invention enables the air conditioning system to better adapt to different working conditions by using the fixed frequency compressor and the variable frequency compressor in combination. Specifically, since the air-conditioning system operates under low-load conditions during most of the working hours, and the inverter compressor has high energy efficiency during partial-load operation, the air-conditioning system can first control the inverter compressor In order to effectively improve the energy efficiency of the air conditioning system under low load conditions; when the actual capacity percentage of the inverter compressor reaches the first preset frequency conversion capacity percentage, the air conditioning system can The actual load demand percentage of the compressor of the system judges whether the inverter compressor alone is sufficient to meet the user's heat exchange requirements. If the inverter compressor alone cannot meet the user's needs, the air conditioning system controls the fixed frequency compressor to operate. , so as to effectively ensure that the air conditioning system can operate efficiently under any working conditions.

Description of drawings

Fig. 1 is the main step flow chart of the compressor control method of the present invention;

Fig. 2 is a flow chart of specific steps of a preferred embodiment of the compressor control method of the present invention.

Detailed ways

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principle of the present invention, and are not intended to limit the protection scope of the present invention. For example, although the various steps of the method of the present invention are described in this application in a specific order, these orders are not limiting, and those skilled in the art may perform different orders without departing from the basic principles of the present invention. Perform the described steps.

Specifically, the air conditioning system of the present invention includes an indoor unit, an outdoor unit, and a main circulation loop arranged between the indoor unit and the outdoor unit, and the main circulation loop is provided with a fixed-frequency compressor and a variable-frequency compressor in parallel. At the same time, the air conditioning system is also provided with a water exchange circuit, and the main circulation circuit is connected with the hot water exchange circuit, so that the refrigerant in the main circulation circuit can be exchanged with the water in the hot water exchange circuit The heat is further exchanged with the indoor air through the hot water exchange path. It can be understood by those skilled in the art that the present invention does not impose any limitation on the specific numbers and types of the fixed-frequency compressors and the variable-frequency compressors, and the technicians can set them by themselves according to actual use requirements. In addition, the present invention does not impose any restrictions on the specific structure of the air-conditioning system, and technicians can set the specific structure of the air-conditioning system according to the actual use requirements, as long as the air-conditioning system includes fixed-frequency compressors connected in parallel and inverter compressor.

Further, the air conditioning system of the present invention further includes a controller, which can acquire detection data of each detection element, for example, acquire detection data of a temperature sensor disposed on the hot water exchange circuit to obtain the hot water exchange circuit and the controller can also control the operation of the air conditioning system, for example, control the actual operating capability of the fixed-frequency compressor, and control the actual operating capability and operating frequency of the variable-frequency compressor. Of course, those skilled in the art can also understand that the present invention does not impose any restrictions on the specific structure and model of the controller, and the controller may be the original controller of the air-conditioning system, or it may be a controller for execution For the controller independently set according to the compressor control method of the present invention, the technical personnel can set the structure and model of the controller according to the actual use requirements.

First, please refer to FIG. 1 , which is a flow chart of the main steps of the compressor control method of the present invention. As shown in FIG. 1, based on the air-conditioning system described in the above embodiment, the compressor control method of the present invention mainly includes the following steps:

S1: In the case of the inverter compressor running alone, detect the actual capacity percentage of the inverter compressor;

S2: when the actual capacity percentage of the variable frequency compressor reaches the first preset frequency conversion capacity percentage, obtain the actual load demand percentage of the compressor of the air conditioning system;

S3: According to the actual load demand percentage of the compressor of the air-conditioning system, the fixed-frequency compressor is selectively operated according to different capacity percentages.

Further, in step S1, the controller can control the variable frequency compressor to operate before the fixed frequency compressor, so as to detect the actual capacity of the variable frequency compressor when the variable frequency compressor operates alone Since the inverter compressor has high energy efficiency and obvious energy saving effect when running under partial load, the controller can first control the operation of the inverter compressor, so as to effectively ensure that the air conditioning system can operate under low load conditions. Guaranteed high energy efficiency. It can be understood by those skilled in the art that the present invention does not impose any restrictions on the initial actual capability of the variable frequency compressor when it is started, and the technicians can set it according to the actual use requirements; at the same time, the present invention does not limit the startup of the variable frequency compressor. The technical personnel can set the compressor control method of the inverter compressor by themselves according to the actual use requirements.

Further, in step S2, first of all, it should be noted that, after the inverter compressor starts to operate, according to the operation requirements of the air conditioning system, the controller may perform an operation on the actual capacity of the inverter compressor. Adjustment control. When the heat exchange demand of the air conditioning system is strong, the initial actual capacity of the variable frequency compressor is often difficult to meet the operating requirements of the air conditioning system. At this time, the controller will increase the frequency conversion compressor. actual ability. When the actual capacity percentage of the variable frequency compressor reaches a first preset frequency conversion capacity percentage, the controller acquires the actual compressor load demand percentage of the air conditioning system, so that the controller can The actual load demand percentage of the machine is used to judge whether the use of the inverter compressor alone is enough to meet the heat exchange demand of the user. It can be understood that the technical personnel can set the specific value of the first preset frequency conversion capability percentage by themselves according to actual use requirements, and preferably, the first preset frequency conversion capability percentage is 50%. In addition, it should be noted that the present invention does not impose any restrictions on the specific method for the controller to obtain the actual load demand percentage of the compressor, and the technical personnel can set the specific acquisition method according to the actual use requirements, as long as the controller can The load demand of the air-conditioning system on the compressor can be determined according to the actual load demand percentage of the compressor.

Further, in step S3, the controller can selectively make the fixed-frequency compressor operate according to different capacity percentages according to the actual load demand percentage of the compressor of the air-conditioning system. It can be understood that the controller can determine, according to the actual load demand percentage of the compressor of the air conditioning system, that when the actual capacity percentage of the variable frequency compressor reaches the first preset frequency conversion capacity percentage, the air conditioning system alone Whether the use of the variable frequency compressor is sufficient to meet the heat exchange requirements of the user, in the case that the use of the variable frequency compressor alone can no longer meet the user's needs, the controller controls the fixed frequency compressor to operate according to different capacity percentages, Therefore, it is effectively ensured that the air conditioning system can operate efficiently under any working conditions. Of course, it should also be noted that the present invention does not impose any restrictions on the specific judgment method used in this step. For example, the controller may compare the actual load demand percentage of the compressor of the air conditioning system with the preset demand percentage , the actual load demand percentage of the compressor of the air conditioning system can also be brought into the relational expression for judgment, and the technician can set its specific judgment method according to the actual use demand.

2 , which is a flow chart of specific steps of a preferred embodiment of the compressor control method of the present invention. As shown in FIG. 2, based on the air conditioning system described in the above embodiments, a preferred embodiment of the compressor control method of the present invention specifically includes the following steps:

S101: In the case of the inverter compressor running alone, detect the actual capacity percentage of the inverter compressor;

S102: Determine whether the actual capacity percentage of the inverter compressor is greater than or equal to 50%; if yes, go to step S105; if not, go to step S103;

S103: Determine whether the difference between the actual water temperature and the target water temperature is equal to zero; if so, execute step S104; if not, execute step S101 again;

S104: stop the inverter compressor;

S105: Obtain the actual load demand percentage of the compressor of the air-conditioning system;

S106: Determine whether the actual load demand percentage of the compressor is greater than or equal to fifty percent; if yes, go to step S108; if not, go to step S107;

S107: Keep the inverter compressor running at fifty percent of its capacity;

S108: Make the fixed frequency compressor run at 25% capacity;

S109: Obtain the actual load demand percentage of the compressor of the air-conditioning system again;

S110: Determine whether the actual compressor load demand percentage is greater than or equal to 50%; if yes, go to step S111; if not, go to step S122;

S111: Make the fixed frequency compressor run at fifty percent capacity;

S112: Obtain the actual load demand percentage of the compressor of the air conditioning system again;

S113: Determine whether the actual compressor load demand percentage is greater than or equal to 50%; if yes, go to step S114; if not, go to step S122;

S114: Make the fixed frequency compressor run at 75% capacity;

S115: Obtain the actual load demand percentage of the compressor of the air conditioning system again;

S116: Determine whether the actual compressor load demand percentage is greater than or equal to fifty percent; if yes, go to step S117; if not, go to step S122;

S117: Make the inverter compressor run at 75% capacity;

S118: Obtain the actual load demand percentage of the compressor of the air conditioning system again;

S119: Determine whether the actual compressor load demand percentage is greater than or equal to ten percent; if yes, go to step S120; if not, go to step S121;

S120: Make the fixed frequency compressor run at full load;

S121: Make both the variable frequency compressor and the fixed frequency compressor run at the current capacity percentage;

S122: Stop the fixed frequency compressor.

Further, in step S101, when the air conditioning system is started, the controller can control the variable frequency compressor to start before the fixed frequency compressor, so as to effectively ensure that the air conditioning system can also be operated at a low load. It can have higher energy efficiency; when the inverter compressor operates alone, the controller can detect the actual capacity percentage of the inverter compressor. It should be noted that according to the statistical data in recent years, when calculated according to the European algorithm, the time of full-load operation of the air-conditioning system usually only accounts for 1.4% of the total operating time, while when calculated according to the American algorithm, the time of full-load operation of the air-conditioning system is The proportion of the total operating time is less than 0.5%; therefore, it is necessary for the air-conditioning system to control the operation of different compressors according to its own load conditions, so as to effectively improve the energy efficiency of the air-conditioning system, thereby effectively guaranteeing all The air conditioning system can maintain high energy efficiency under various working conditions. In addition, it should be noted that the present invention does not impose any restrictions on the initial capacity percentage of the variable frequency compressor when it is started, and technicians can set it according to actual use requirements.

Further, in step S102, since when the actual capacity percentage of the variable frequency compressor is less than 50%, the energy efficiency of the variable frequency compressor is usually significantly higher than that of the fixed frequency compressor; therefore, in all After the inverter compressor starts to run, the controller can determine whether the actual capacity percentage of the inverter compressor is greater than or equal to fifty percent, so as to determine that the controller should increase the actual capacity percentage of the inverter compressor. The fixed frequency compressor should still be started. It can be understood by those skilled in the art that although the first preset frequency conversion capability percentage described in this preferred embodiment is 50%, it is obvious that technicians can also set the first preset frequency conversion capability according to actual usage requirements. The specific value of the preset frequency conversion capacity percentage. In addition, it should be noted that technicians can set the calculation method of the actual capacity percentage of the inverter compressor by themselves according to the actual use requirements. As an embodiment, the calculation method of the actual capacity percentage of the inverter compressor is as follows:

Qa*100%=k1*Tev+k2*Tco+k3*A _c

Wherein, k1 is the first frequency conversion coefficient, k2 is the second frequency conversion coefficient, k3 is the third frequency conversion coefficient, and the first frequency conversion coefficient, the second frequency conversion coefficient and the third frequency conversion coefficient are all compressed by the frequency conversion The specific model of the compressor is determined; Tev is the current evaporating temperature of the inverter compressor, the unit is °C; Tco is the current condensing temperature of the inverter compressor, the unit is °C; A _c is the current operating current of the inverter compressor , the unit is A.

It should be noted that the technical personnel need to determine the specific values of the first frequency conversion coefficient, the second frequency conversion coefficient and the third frequency conversion coefficient according to the specific model of the frequency conversion compressor; The specific manner in which the controller obtains the current evaporating temperature, the current condensing temperature and the current operating current of the variable frequency compressor is subject to any restrictions, which can be set by the technicians according to actual use requirements. In addition, it should be noted that the actual capacity percentage of the fixed-frequency compressor can also be calculated with reference to the above-mentioned calculation formula, and the technician only needs to replace the parameters in the above-mentioned calculation formula with the corresponding parameters of the fixed-frequency compressor. Yes; at the same time, the three coefficients involved in the above calculation formula also need to be determined according to the specific model of the fixed-frequency compressor.

Further, if the actual capacity percentage of the inverter compressor does not reach 50%, step S103 is executed, that is, the controller can obtain the actual water temperature of the hot water exchange circuit, and calculate the actual water temperature and the user The difference between the set target water temperatures is used to determine whether the difference is equal to zero, that is, whether the actual water temperature of the hot water exchange circuit is equal to the target water temperature set by the user. If the actual water temperature of the hot water exchange circuit is equal to the target water temperature set by the user, it means that the air conditioning system has been able to meet the heat exchange demand of the user. Due to the large specific heat capacity of water, the water temperature in the hot water exchange circuit will not drop sharply. In this case, step S104 is executed, that is, the controller controls the inverter compressor to stop, so as to maintain the heat exchange effect by relying on the residual temperature in the hot water exchange circuit, thereby effectively achieving the energy saving effect. If the actual water temperature of the hot water exchange circuit is not equal to the target water temperature set by the user, it means that the air conditioning system is not enough to meet the user's heat exchange needs, and the water in the hot water exchange circuit needs to be further exchanged with refrigerant. heat; in this case, the controller may perform step S101 again after changing the operating parameters of the inverter compressor. For example, the controller can further increase the actual capacity percentage of the variable frequency compressor. As an example, the controller can control the performance of the variable frequency compressor according to the difference between the actual water temperature and the target water temperature. Actual capacity percentage. Specifically, the controller may control the change range of the actual capacity percentage of the variable frequency compressor and the continuous operation of the variable frequency compressor under each capacity percentage through the difference between the actual water temperature and the target water temperature. The specific control logic is as follows: the greater the difference between the actual water temperature and the target water temperature, the faster the increase speed of the actual capacity percentage of the inverter compressor, and the inverter compressor in a relatively low actual The continuous operation time at the capacity percentage is also shorter; on the contrary, the smaller the difference between the actual water temperature and the target water temperature, the slower the increasing speed of the actual capacity percentage of the inverter compressor, and the inverter compressor is in the The duration of operation is also longer at a relatively low percentage of actual capacity. It should be noted that, in the entire compressor control method of the present invention, the controller can use this control logic when adjusting the actual capacity percentage of the variable frequency compressor and the fixed frequency compressor. Of course, , this control logic is not restrictive, and technicians can also set their specific control logic according to actual use requirements.

Further, in step S105, if the actual capacity percentage of the inverter compressor has reached 50%, the controller can obtain the actual compressor load demand percentage of the air conditioning system; it should be noted that, The technical personnel can set the specific calculation method of the actual load demand percentage of the compressor of the air conditioning system by themselves according to the actual use demand. As an embodiment, the calculation method of the actual compressor load demand percentage of the air conditioning system is as follows:

m*100%=(T _a -T _t )/T _diff

Wherein, T _a is the actual water temperature of the hot water exchange circuit of the air conditioning system, in °C; T _t is the target water temperature of the air conditioning system, in °C; T _diff is the compressor startup temperature difference, in °C.

It should be noted that the start-up temperature difference of the compressor needs to be set by the technicians according to the actual use requirements. At the same time, when the difference between the actual water temperature and the target water temperature is greater than the start-up temperature difference of the compressor, directly The actual compressor load demand percentage of the air conditioning system is determined to be 100%.

Further, in step S106, if the controller determines that the actual load demand percentage of the compressor of the air conditioning system is less than 50%, it means that only maintaining the current capacity percentage of the inverter compressor is sufficient to meet the user's demand. Heat exchange demand, in this case, step S107 is performed, that is, the controller controls the inverter compressor to maintain the operation at 50% capacity. At the same time, if the controller determines that the actual load demand percentage of the compressor of the air conditioning system is greater than or equal to 50%, it means that only maintaining the current capacity percentage of the inverter compressor can no longer meet the heat exchange demand of the user, In this case, step S108 is executed, that is, the controller controls the fixed-frequency compressor to start and operate at a capacity of 25%, so as to effectively meet the heat exchange demand of the user. It should be noted that although the first preset demand percentage described in this preferred embodiment is 50%, it is obvious that technicians can also set the first preset demand percentage by themselves according to actual use requirements. specific value. At the same time, although the percentage of the first preset frequency setting capability described in this preferred embodiment is 25%, it is obvious that technicians can also set the first preset frequency setting capability by themselves according to actual usage requirements The specific value of the percentage.

Further, after the fixed-frequency compressor operates at a capacity of 25%, step S109 is executed, that is, the controller can obtain the actual load demand percentage of the compressor of the air-conditioning system again, so as to determine the Whether the current heat exchange capacity of the air conditioning system is sufficient to meet the heat exchange needs of users. In step S110, if the controller determines that the actual load demand percentage of the compressor of the air conditioning system is less than 50%, it means that the heat exchange capacity of the air conditioning system at this time is sufficient to meet the heat exchange demand of the user, In this case, in order to effectively save energy, step S122 is executed, that is, the controller can control the fixed-frequency compressor to stop, and only use the variable-frequency compressor to participate in heat exchange. If the controller determines that the actual load demand percentage of the compressor of the air conditioning system is greater than or equal to 50%, it means that the heat exchange capacity of the air conditioning system at this time is not enough to meet the heat exchange demand of the user. Here In this case, step S111 is executed, that is, the controller can control the fixed-frequency compressor to operate at 50% capacity, so as to effectively improve the heat exchange capacity of the air-conditioning system.

Further, after the fixed-frequency compressor runs at 50% capacity, step S112 is executed, that is, the controller can obtain the actual load demand percentage of the compressor of the air-conditioning system again, so as to determine the Whether the current heat exchange capacity of the air conditioning system is sufficient to meet the heat exchange needs of users. In step S113, if the controller determines that the actual load demand percentage of the compressor of the air conditioning system is less than 50%, it means that the heat exchange capacity of the air conditioning system at this time is sufficient to meet the heat exchange demand of the user, In this case, in order to effectively save energy, step S122 is executed, that is, the controller can control the fixed-frequency compressor to stop, and only use the variable-frequency compressor to participate in heat exchange. If the controller determines that the actual load demand percentage of the compressor of the air conditioning system is greater than or equal to 50%, it means that the heat exchange capacity of the air conditioning system at this time is not enough to meet the heat exchange demand of the user. Here In this case, step S114 is executed, that is, the controller can control the fixed-frequency compressor to operate at a capacity of 75%, so as to effectively improve the heat exchange capacity of the air-conditioning system. Those skilled in the art can understand that, although the second preset frequency capability percentage described in this preferred embodiment is 75%, it is obvious that the technical personnel can also set the The specific value of the second preset frequency capability percentage; at the same time, although this preferred embodiment does not directly increase the actual capability percentage of the fixed-frequency compressor from the first preset frequency capability percentage to the first preset frequency capability percentage 2. Preset frequency capability percentage. Obviously, technicians can set the actual capability percentage of the fixed-frequency compressor to increase from the first preset frequency capability percentage to the second preset capacity percentage based on actual usage requirements. The specific process of the percentage of fixed frequency capability.

Further, after the fixed-frequency compressor operates at a capacity of 75%, step S115 is executed, that is, the controller can obtain the actual load demand percentage of the compressor of the air-conditioning system again, so as to determine the Whether the current heat exchange capacity of the air conditioning system is sufficient to meet the heat exchange needs of users. In step S116, if the controller determines that the actual load demand percentage of the compressor of the air conditioning system is less than 50%, it means that the heat exchange capacity of the air conditioning system at this time is sufficient to meet the heat exchange demand of the user, In this case, in order to effectively achieve the energy saving effect, step S122 is executed, that is, the controller can control the fixed-frequency compressor to stop, and only use the variable-frequency compressor to participate in heat exchange. If the controller determines that the actual load demand percentage of the compressor of the air conditioning system is still greater than or equal to 50%, it means that the heat exchange capacity of the air conditioning system at this time is not enough to meet the heat exchange demand of the user. In this case, step S117 is performed, that is, the controller increases the actual operating capacity of the inverter compressor to 75%, so as to effectively improve the heat exchange capacity of the air conditioning system. It should be noted that although the percentage of the second preset frequency conversion capability described in this preferred embodiment is 75%, it is obvious that the technical personnel can also set the second preset frequency conversion capacity by themselves according to the actual use requirements. The specific value of the ability percentage.

Further, after both the variable frequency compressor and the fixed frequency compressor are running at 75% capacity, step S118 is executed, that is, the controller can obtain the actual compressor of the air conditioning system again. Load demand percentage, so as to judge whether the current heat exchange capacity of the air conditioning system is sufficient to meet the heat exchange demand of users. In step S119, since both the variable frequency compressor and the fixed frequency compressor are already in a state of high-load operation at this time, it means that the air-conditioning system needs a higher heat exchange capacity to be sufficient to meet the heat exchange demand of the user In this case, in order to effectively ensure the heat exchange effect of the air conditioning system, the controller needs to determine whether the actual load demand percentage of the compressor of the air conditioning system is greater than or equal to ten percent. If the controller determines that the actual load demand percentage of the compressor of the air conditioning system is less than ten percent, it means that the heat exchange capacity of the air conditioning system at this time is sufficient to meet the heat exchange demand of the user. In this case, in order to To effectively ensure the high heat exchange capacity of the air-conditioning system, step S121 is executed, that is, the controller can control both the variable-frequency compressor and the fixed-frequency compressor to operate at the current capacity percentage, thereby effectively ensuring the air-conditioning system. The heat exchange capacity can always meet the user's heat exchange needs. At the same time, if the controller determines that the actual load demand percentage of the compressor of the air conditioning system is greater than or equal to ten percent, it means that the heat exchange capacity of the air conditioning system at this time is still insufficient to meet the heat exchange demand of the user. In this case, in order to further improve the heat exchange capacity of the air-conditioning system, step S120 is executed, that is, the controller controls the fixed-frequency compressor to operate at full load, that is, the actual operation of the fixed-frequency compressor is adjusted. The capacity is increased to 100%, so as to further improve the heat exchange capacity of the air conditioning system.

It should be noted that although the second preset demand percentage described in this preferred embodiment is 10%, it is obvious that the technical personnel can also set the specific second preset demand percentage by themselves according to the actual use demand. numerical value. In addition, under the condition that the inverter compressor is running at 75% capacity and the fixed-frequency compressor is running at full load, if the heat exchange capacity of the air conditioning system is still insufficient to meet the user's heat exchange demand, the controller can also control the inverter compressor to run at full load, so as to maximize the heat exchange capacity of the air conditioning system.

Finally, it should be noted that the above-mentioned embodiments are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. When those skilled in the art actually use the present invention, some steps may be appropriately added or deleted as required, or the order of different steps may be exchanged. Such changes do not go beyond the basic principles of the present invention, and belong to the protection scope of the present invention.

So far, the preferred embodiments of the present invention have been described with reference to the accompanying drawings, however, those skilled in the art can easily understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims (6)

1. A compressor control method for an air conditioning system, wherein the air conditioning system comprises a fixed-frequency compressor and an inverter compressor which are connected in parallel, the compressor control method comprising:

detecting the actual capacity percentage of the inverter compressor under the condition that the inverter compressor operates alone;

when the actual capacity percentage of the variable-frequency compressor reaches a first preset variable-frequency capacity percentage, acquiring the actual load demand percentage of the compressor of the air conditioning system;

selectively operating the fixed-frequency compressor according to different capacity percentages according to the actual load demand percentage of the compressor of the air conditioning system;

the actual load demand percentage of a compressor of the air-conditioning system is equal to the difference value between the actual water temperature and the target water temperature of the air-conditioning system divided by the starting temperature difference of the compressor; and/or

The actual capacity percentage of the inverter compressor is equal to a first frequency conversion coefficient multiplied by the current evaporation temperature of the inverter compressor plus a second frequency conversion coefficient multiplied by the current condensation temperature of the inverter compressor plus a third frequency conversion coefficient multiplied by the current operating current of the inverter compressor; wherein the first, second and third frequency conversion coefficients are determined by a model of the inverter compressor; and/or

The actual capacity percentage of the fixed-frequency compressor is equal to a first fixed-frequency coefficient multiplied by the current evaporation temperature of the fixed-frequency compressor plus a second fixed-frequency coefficient multiplied by the current condensation temperature of the fixed-frequency compressor plus a third fixed-frequency coefficient multiplied by the current operation current of the fixed-frequency compressor; wherein the first fixed frequency coefficient, the second fixed frequency coefficient and the third fixed frequency coefficient are determined by the model of the fixed frequency compressor;

the step of selectively operating the fixed-frequency compressor at different capacity percentages based on the percentage of actual load demand of the compressor of the air conditioning system comprises:

comparing the actual load demand percentage of the compressor of the air conditioning system with a first preset demand percentage;

if the actual load demand percentage of the compressor of the air conditioning system is greater than or equal to the first preset demand percentage, enabling the fixed-frequency compressor to operate at a first preset frequency capacity percentage;

after the step of operating the fixed frequency compressor at the first preset frequency capacity percentage, the compressor control method further comprises:

acquiring the actual load demand percentage of the compressor of the air conditioning system again;

comparing the obtained actual load demand percentage of the compressor of the air conditioning system with the first preset demand percentage;

if the actual load demand percentage of the compressor of the air conditioning system is still greater than or equal to the first preset demand percentage, increasing the actual capacity percentage of the fixed-frequency compressor and repeatedly executing the obtaining and comparing steps until the actual capacity percentage of the fixed-frequency compressor is increased to a second preset capacity percentage; and/or

If the actual load demand percentage of the compressor of the air conditioning system is smaller than the first preset demand percentage, stopping the fixed-frequency compressor;

after the actual capacity percentage of the fixed-frequency compressor is increased to the second preset frequency capacity percentage, the compressor control method further comprises:

acquiring the actual load demand percentage of the compressor of the air conditioning system again;

comparing the actual compressor load demand percentage of the air conditioning system obtained again with the first preset demand percentage;

if the actual load demand percentage of the compressor of the air conditioning system obtained again is still larger than or equal to the first preset demand percentage, the actual capacity percentage of the inverter compressor is increased to a second preset inverter capacity percentage; and/or

And if the actual load demand percentage of the compressor of the air conditioning system is smaller than the first preset demand percentage, stopping the fixed-frequency compressor.

2. The compressor control method according to claim 1, wherein after the step of "increasing the actual capacity percentage of the inverter compressor to a second preset inverter capacity percentage", the compressor control method further comprises:

further acquiring the actual load demand percentage of a compressor of the air conditioning system;

comparing the further acquired actual load demand percentage of the compressor of the air conditioning system with a second preset demand percentage;

and selectively controlling the fixed-frequency compressor and the variable-frequency compressor to work cooperatively according to the comparison result.

3. The compressor control method of claim 2, wherein the step of selectively controlling the fixed frequency compressor and the inverter compressor to cooperate according to the comparison result comprises:

if the further acquired actual load demand percentage of the compressor of the air conditioning system is larger than or equal to the second preset demand percentage, enabling the fixed-frequency compressor to run at full load; and/or

And if the further acquired actual load demand percentage of the compressor of the air conditioning system is smaller than the second preset demand percentage, enabling the fixed-frequency compressor and the variable-frequency compressor to operate at the current capacity percentage.

4. The compressor control method according to any one of claims 1 to 3, wherein the first preset percent variable frequency capacity is 50%.

5. The compressor control method according to any one of claims 1 to 3, wherein the first preset demand percentage is 50%; and/or

The first predetermined percentage of frequency capability is 25%.

6. A compressor control method according to claim 2 or 3, characterized in that said second preset frequency capacity percentage is 75%; and/or

The second preset percent variable frequency capability is 75%; and/or

The second predetermined percentage of frequency capability is 10%.

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