Air conditioner and control method of air conditioner

Abstract

The invention discloses an air conditioner and a control method of the air conditioner. The evaporator comprises M first pipelines; the condenser comprises N second pipelines; the X electromagnetic valves comprise M first electromagnetic valves and N second electromagnetic valves, each first electromagnetic valve is correspondingly arranged on each first pipeline and used for connecting or disconnecting the corresponding first pipeline, each second electromagnetic valve is correspondingly arranged on each second pipeline and used for connecting or disconnecting the corresponding second pipeline and used for connecting or disconnecting the corresponding second pipeline; the second electromagnetic valves are used for connecting or disconnecting the corresponding second pipelines; and a refrigerant circuit that circulates a refrigerant in the compressor, the evaporator, the throttle valve, and the condenser. By the adoption of the air conditioner, oil return and tripping protection of the compressor can be achieved, and the use experience of a user is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioners, in particular to an air conditioner and a control method of the air conditioner. BACKGROUND

[0002] In some war-torn or underdeveloped areas, consumers use air conditioners powered by diesel generators due to price issues. However, diesel power generation has a maximum current limit. When the user uses the air conditioner, the air conditioner will adopt a current limiting control mode, that is, low-frequency operation does not exceed the maximum current of the diesel generator. However, if the air conditioner is operated at low frequency for a long time, the compressor will be starved of oil, causing the compressor to wear and be damaged. If the compressor is starved of oil, the compressor frequency needs to be increased to bring the lubricating oil attached to the refrigerant pipe system back to the compressor. However, due to the user's current specification limit, the current increases when the compressor operates at high frequency. If the current exceeds the user's specification, the circuit breaker will trip, causing the user to be unable to use the air conditioner normally. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, one object of the present application is to provide an air conditioner that can balance the problems of compressor oil return and tripping protection, thereby improving the user experience.

[0004] A second object of the present application is to provide a control method of an air conditioner.

[0005] To solve the above problems, the first aspect of the present application provides an air conditioner, comprising: a compressor; an evaporator comprising M first pipes; a condenser comprising N second pipes; X electromagnetic valves, X electromagnetic valves comprising M first electromagnetic valves and N second electromagnetic valves, each first electromagnetic valve being arranged on each first pipe, the first electromagnetic valve being used to open or close the corresponding first pipe, each second electromagnetic valve being arranged on each second pipe, the second electromagnetic valve being used to open or close the corresponding second pipe; and a refrigerant circuit, which circulates refrigerant in the compressor, the evaporator, a throttling valve, and the condenser.

[0006] The first aspect of the present application provides an air conditioner with a controller configured to: if the air conditioner meets the oil return control condition, if the air conditioner is in a cooling mode, control a plurality of second electromagnetic valves to be fully on, and control M first electromagnetic valves to be alternately on, so as to make the plurality of first pipes be alternately on; if the air conditioner is in a heating mode, control a plurality of first electromagnetic valves to be fully on, and control N second electromagnetic valves to be alternately on, so as to make the plurality of second pipes be alternately on.

[0007] According to the air conditioner provided in the embodiment of the present application, the electromagnetic valves are arranged on each pipe of the evaporator and each pipe of the condenser respectively, and the on-off state of each electromagnetic valve is controlled to open only one pipe of the evaporator or the condenser in different operation modes of the air conditioner, so that when the compressor is frequency-increased, the refrigerant accumulates in the condenser or the evaporator, thereby reducing the circulation amount of the refrigerant in the whole refrigerant circuit, reducing the load of the compressor, increasing the flow rate of the refrigerant, realizing the oil return of the compressor, and simultaneously reducing the working current of the whole machine due to the reduced circulation amount of the refrigerant, so that even if the compressor is frequency-increased, the change of the working current of the whole machine is small, thereby achieving the purpose that the current does not exceed the limit requirement when the frequency is increased, avoiding the problem that the user cannot use the machine due to tripping and limiting power, and improving the user experience.

[0008] In some embodiments, the controller is further configured to: when controlling the M first electromagnetic valves to alternately conduct, control the on duration of each first electromagnetic valve to reach a first preset duration; and when controlling the N second electromagnetic valves to alternately conduct, control the on duration of each second electromagnetic valve to reach a second preset duration. In this way, the pipe pressure of the evaporator or the condenser is maximized within the first preset duration or the second preset duration, so as to facilitate the subsequent release of lubricating oil on the pipe wall.

[0009] In some embodiments, the controller is further configured to: when controlling the M first electromagnetic valves to alternately conduct, control the last first electromagnetic valve to be closed after the on duration of the currently conducting first electromagnetic valve reaches a third preset duration; and when controlling the N second electromagnetic valves to alternately conduct, control the last second electromagnetic valve to be closed after the on duration of the currently conducting second electromagnetic valve reaches a fourth preset duration. In this way, the system pressure is slowly recovered, and the air conditioner pressure balance is ensured.

[0010] In some embodiments, the oil return control condition at least includes that the operation duration of the compressor reaches a fifth preset duration.

[0011] In some embodiments, the controller is further configured to: prohibit the air conditioner from responding to other function instructions; and control the air conditioner to return to a normal operation state when the air conditioner satisfies an oil return control end condition.

[0012] The second aspect embodiment of the present application provides an air conditioner control method, which is used for the air conditioner described in the above embodiments, and the control method comprises: if the air conditioner is in a cooling mode when the air conditioner satisfies an oil return control condition, controlling a plurality of second electromagnetic valves to be fully conducted and controlling M first electromagnetic valves to be alternately conducted, so as to alternately conduct the plurality of first pipes; and if the air conditioner is in a heating mode, controlling a plurality of first electromagnetic valves to be fully conducted and controlling N second electromagnetic valves to be alternately conducted, so as to alternately conduct the plurality of second pipes.

[0013] According to the control method of the air conditioner, based on the electromagnetic valves respectively arranged on each pipeline of the evaporator and each pipeline of the condenser, by controlling the conduction of each electromagnetic valve to make only one pipeline of the evaporator or the condenser open in different operation modes of the air conditioner, when the compressor is frequency-increased, the refrigerant accumulates in the condenser or the evaporator, thereby reducing the refrigerant circulation amount in the whole refrigerant circuit, reducing the compressor load, improving the refrigerant flow rate, realizing the compressor oil return, and simultaneously, due to the reduction of the refrigerant circulation amount, the whole machine working current is also reduced, so that even if the compressor is frequency-increased, the change of the whole machine working current is small, thereby achieving the purpose that the current does not exceed the limit requirement when the frequency is increased, avoiding the problem that the user cannot use due to tripping and limiting power, and improving the user experience.

[0014] In some embodiments, the control method further comprises: when controlling the M first electromagnetic valves to alternately conduct, controlling the conduction time length of each first electromagnetic valve to reach a first preset time length; and when controlling the N second electromagnetic valves to alternately conduct, controlling the conduction time length of each second electromagnetic valve to reach a second preset time length. In this way, the pipeline pressure of the evaporator or the condenser is maximized within the first preset time length or the second preset time length, so as to facilitate the subsequent release of the pressure to fully bring out the lubricating oil on the pipe wall.

[0015] In some embodiments, the control method further comprises: when controlling the M first electromagnetic valves to alternately conduct, after the conduction time length of the currently conducting first electromagnetic valve reaches a third preset time length, controlling the last conducting first electromagnetic valve to close; and when controlling the N second electromagnetic valves to alternately conduct, after the conduction time length of the currently conducting second electromagnetic valve reaches a fourth preset time length, controlling the last conducting second electromagnetic valve to close. In this way, the system pressure is slowly recovered, and the air conditioner pressure balance is ensured.

[0016] In some embodiments, the oil return control condition at least comprises: the operation time length of the compressor reaches a fifth preset time length.

[0017] In some embodiments, the control method further comprises: inhibiting the air conditioner from responding to other function instructions; and until the air conditioner satisfies the oil return control end condition, controlling the air conditioner to return to a normal operation state.

[0018] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and / or additional aspects and advantages of the application will become apparent and be readily understood by considering the following detailed description, from which the above-mentioned and other aspects, advantages, and features of the application become apparent, and by practicing the application in connection with the following detailed description, the appended claims, and the accompanying drawings in which:

[0020] Figure 1 is a structural schematic diagram of an air conditioner according to an embodiment of the present application;

[0021] Figure 2 is a structural schematic diagram of an evaporator according to an embodiment of the present application;

[0022] Figure 3 is a structural schematic diagram of a condenser according to an embodiment of the present application;

[0023] Figure 4 is a refrigerant flow direction schematic diagram of an air conditioner in a heating mode according to an embodiment of the present application;

[0024] Figure 5 is a refrigerant flow direction schematic diagram of an air conditioner in a cooling mode according to an embodiment of the present application;

[0025] Figure 6 is a flow chart of a control method of an air conditioner according to an embodiment of the present application;

[0026] Figure 7 is a flow chart of a control method of an air conditioner according to another embodiment of the present application;

[0027] Figure 8 is a flow chart of a control method of an air conditioner according to another embodiment of the present application;

[0028] Figure 9 is a structural schematic diagram of an air conditioner according to another embodiment of the present application;

[0029] Figure 10 is a structural schematic diagram of an air conditioner according to another embodiment of the present application. DETAILED DESCRIPTION

[0030] Embodiments of the present application are described in detail below with reference to the accompanying drawings. The embodiments described below are exemplary, and the embodiments of the present application are described in detail below.

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0032] In the description of the present application, it needs to be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0033] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified and limited, the meaning of "a plurality of" is two or more.

[0034] In the description of the present application, it needs to be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] In the present application, the air conditioner performs a refrigeration cycle of the air conditioner by using a compressor, a condenser, an expansion valve and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion and evaporation, and supplies refrigerant to the air that has been adjusted and heat exchanged.

[0036] The compressor compresses the refrigerant gas in a high-temperature and high-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

[0037] The expansion valve expands the high-temperature and high-pressure liquid phase refrigerant condensed in the condenser into a low-pressure liquid phase refrigerant. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. The evaporator can achieve a refrigeration effect by exchanging heat with the material to be cooled using the latent heat of evaporation of the refrigerant. Throughout the cycle, the air conditioner can adjust the temperature of the indoor space.

[0038] The outdoor unit of the air conditioner refers to the part of the refrigeration cycle including the compressor and the outdoor heat exchanger, the indoor unit of the air conditioner includes the indoor heat exchanger, and the expansion valve can be provided in the indoor unit or the outdoor unit.

[0039] The indoor heat exchanger and the outdoor heat exchanger are used as a condenser or an evaporator. When the indoor heat exchanger is used as a condenser, the air conditioner is used as a heater in a heating mode, and when the indoor heat exchanger is used as an evaporator, the air conditioner is used as a cooler in a cooling mode.

[0040] In the related art, taking the cooling mode as an example, during the operation of the air conditioner, the compressor lubricating oil is discharged from the compressor together with the refrigerant, circulates through the system refrigerant circuit, and returns to the compressor. However, the refrigerant undergoes a phase change in the entire system, and the lubricating oil is in a liquid state. When the refrigerant changes from a liquid state to a gaseous state, the lubricating oil precipitates and adheres to the pipeline. Therefore, from the superheated zone to the gas pipe, since the refrigerant is in the process of changing from a liquid state to a gaseous state, the refrigerant is low in temperature and speed, and cannot return to the compressor by gravity, it is necessary to increase the frequency of the compressor operation to accelerate the speed of the refrigerant to bring the lubricating oil back to the compressor. However, the increase in the frequency of the compressor operation leads to an increase in the current, and if the current specification of the user's home is low, the problem of tripping protection will occur.

[0041] To solve the above problems, the first aspect of the present application provides an air conditioner driven by a diesel generator, which can balance the problems of compressor oil return and tripping protection, and improve the user experience.

[0042] The following refers to Figure 1 The air conditioner 100 according to the embodiments of the present application includes a compressor 1, an evaporator 3, a condenser 4, an electromagnetic valve 5, and a controller 6 (not shown in the figure).

[0043] The diesel generator is used to drive the compressor 1; the evaporator 3 includes M first pipelines 30; the condenser 4 includes N second pipelines 40; the number of electromagnetic valves 5 is X, which specifically includes M first electromagnetic valves 51 and N second electromagnetic valves 52, each first electromagnetic valve 51 is correspondingly arranged on each first pipeline 30, and the first electromagnetic valve 51 is used to turn on or turn off the corresponding first pipeline 30, and each second electromagnetic valve 52 is correspondingly arranged on each second pipeline 40, and the second electromagnetic valve 52 is used to turn on or turn off the corresponding second pipeline 40.

[0044] A refrigerant circuit is provided, which circulates the refrigerant in the compressor 1, the evaporator 3, the throttling valve 5, and the condenser 4.

[0045] In the embodiments, the number of first pipelines 30 and the number of second pipelines 40 are not limited, and the number of first pipelines 30 and the number of second pipelines 40 can be the same or different. For example, the evaporator 2 can include six first pipelines 30, eight first pipelines 30, or ten first pipelines 30, etc.; the condenser 4 can include six second pipelines 40, eight second pipelines 40, or ten second pipelines 40, etc.

[0046] Wherein, in the case of satisfying the electromagnetic valve 5 controllable corresponding pipeline on-off, for the electromagnetic valve 5 on the pipeline setting position is not limited. For example, referring to Figure 2 As shown, each first pipeline 30 of the evaporator 3 is connected to the main pipe after being gathered, and the first electromagnetic valve 51 can be correspondingly arranged at the position before the first pipeline 30 enters the main pipe; referring to Figure 3 As shown, each second pipeline 40 of the condenser 4 is connected to the main pipe after being gathered, and the second electromagnetic valve 52 can be correspondingly arranged at the position before the second pipeline 40 enters the main pipe.

[0047] Normally, when the air conditioner 100 is in heating mode, as shown in Figure 4 As shown, the high-temperature and high-pressure refrigerant discharged from the compressor 1 flows into the evaporator 3, and the refrigerant is heated by heat exchange with indoor air and cooled by heat dissipation while flowing in the evaporator 3. The low-temperature and high-pressure refrigerant whose temperature is taken away by the evaporator 3 is decompressed by the throttle valve 5 to become low-temperature and low-pressure refrigerant. The refrigerant flowing into the condenser 4 through the throttle valve 5 is heated by heat exchange with outdoor air, and the low-temperature gas refrigerant is sucked into the compressor 1 from the condenser 4 through the reservoir.

[0048] When the air conditioner 100 is in cooling mode, as shown in Figure 5 As shown, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 is cooled by the condenser 4 to become medium-temperature and high-pressure liquid refrigerant, and the medium-temperature and high-pressure liquid refrigerant is decompressed by the throttle valve 5 to become low-temperature and low-pressure liquid refrigerant. The low-temperature and low-pressure liquid refrigerant is evaporated by the evaporator 3 to become low-temperature and low-pressure gas refrigerant, and the indoor air is cooled by the heat exchanger surface to achieve the purpose of lowering the indoor temperature. The low-temperature and low-pressure gas refrigerant is sucked into the compressor 1.

[0049] In the above normal operation process of the air conditioner, in order to realize the compressor oil return, referring to Figure 6 As shown, the controller 6 is configured to perform the following steps.

[0050] Step S1, determine whether the air conditioner satisfies the oil return control condition.

[0051] Specifically, based on the air conditioner of the present application using a diesel generator, considering the problem of the maximum current limit of the diesel generator, in order to avoid the problems of compressor oil shortage and tripping limit protection, the oil return control condition is set in advance according to the actual situation, and step S2 or step S3 is executed when the oil return control condition is satisfied; and when the oil return control condition is not satisfied, the air conditioner remains in normal operation state.

[0052] In some embodiments, considering the problem that prolonged low-frequency operation of the air conditioner may cause compressor oil shortage and thus compressor wear, this application sets oil return control conditions based on the compressor's operating time. The specific oil return control conditions include at least the compressor's operating time reaching a fifth preset duration, thereby avoiding prolonged low-frequency operation of the compressor.

[0053] The fifth preset duration is set based on actual conditions such as compressor specifications and is not subject to any restrictions. For example, the fifth preset duration can be 180 minutes.

[0054] In some embodiments, to avoid the problem of compressor oil shortage, additional oil return control conditions, such as pipeline temperature, can be added according to actual needs for determination, and there are no restrictions on this.

[0055] Step S2: If the air conditioner is in cooling mode, control multiple second solenoid valves to be fully open and control M first solenoid valves to be alternately open so that multiple first pipelines are alternately open.

[0056] Specifically, refer to Figure 1 As shown, in cooling mode, all second pipes of the condenser are fully open, while the first pipes in the evaporator are alternately open. That is, the controller first opens only one of the M first pipes, while the other (M-1) first pipes are closed; then it opens any one of the other (M-1) first pipes, while the previously opened first pipe closes again, and the other (M-2) first pipes close as well. This cycle repeats. Therefore, by adding a first solenoid valve to the first pipe of the evaporator to control the refrigerant flow, when the compressor runs at increased frequency, since all (M-1) first pipes are closed at the same time, as the pressure increases... As the compressor frequency increases and the pressure rises, the refrigerant accumulates in the first pipe (M-1) of the evaporator, thus reducing the amount of refrigerant circulating in the entire refrigerant circuit. Therefore, although the compressor frequency increases, the reduced refrigerant circulation lowers the compressor load, resulting in a faster refrigerant flow rate throughout the circuit. This also brings the lubricating oil back to the compressor, achieving oil return. Simultaneously, the reduced refrigerant circulation also lowers the overall operating current. Therefore, even if the compressor frequency increases, the change in overall operating current will be minimal, achieving the goal of increasing frequency without exceeding current limits. This avoids the problem of users being unable to use the machine due to power outages and improves the user experience.

[0057] Step S3: If the air conditioner is in heating mode, control multiple first solenoid valves to be fully open and control N second solenoid valves to be alternately open so that multiple second pipelines are alternately open.

[0058] Specifically, refer to Figure 1As shown, in the heating mode, all the first pipes of the evaporator are all turned on, and the second pipes in the condenser are turned on alternately, that is, the controller controls only one of the N second pipes to be turned on, and the other (N-1) second pipes are all turned off; then controls any one of the other (N-1) second pipes to be turned on, and the second pipe turned on last time is turned off and the other (N-2) second pipes are all turned off, and so on. Thus, by increasing the second electromagnetic valve on the second pipe of the condenser to control the on-off of the refrigerant, when the compressor operates at a higher frequency, since (N-1) second pipes are all turned off at the same time, as the frequency of the compressor increases, the pressure increases, and the refrigerant accumulates in the (N-1) second pipes of the condenser, thereby reducing the refrigerant circulation amount in the entire refrigerant circuit. Therefore, although the frequency of the compressor increases, the load of the compressor decreases due to the reduction of the refrigerant circulation amount, and the refrigerant flow rate in the entire refrigerant circuit is faster, thereby bringing the lubricating oil back to the compressor to realize oil return. At the same time, due to the reduction of the refrigerant circulation amount, the working current of the entire machine is also reduced synchronously. Therefore, even if the compressor increases the frequency, the change of the working current of the entire machine will be small, thereby achieving the purpose of increasing the frequency without exceeding the limit requirement of the current, avoiding the problem that the user cannot use due to tripping and limiting power, and improving the user experience.

[0059] According to the air conditioner provided by the embodiment of the present application, by increasing the electromagnetic valve on each pipe of the evaporator and each pipe of the condenser respectively, and by controlling the on-off of each electromagnetic valve to make only one pipe of the evaporator or the condenser be turned on in different operating modes of the air conditioner, when the compressor increases the frequency, the refrigerant accumulates in the condenser or the evaporator, thereby reducing the refrigerant circulation amount in the entire refrigerant circuit, reducing the load of the compressor, improving the refrigerant flow rate, realizing the oil return of the compressor, and simultaneously reducing the working current of the entire machine due to the reduction of the refrigerant circulation amount. Therefore, even if the compressor increases the frequency, the change of the working current of the entire machine will be small, thereby achieving the purpose of increasing the frequency without exceeding the limit requirement of the current, avoiding the problem that the user cannot use due to tripping and limiting power, and improving the user experience.

[0060] In some embodiments, the controller is further configured to: when controlling the M first electromagnetic valves to be turned on alternately, control the on time of each first electromagnetic valve to reach a first preset time length; and when controlling the N second electromagnetic valves to be turned on alternately, control the on time of each second electromagnetic valve to reach a second preset time length. Thus, the pressure of the pipe of the evaporator or the condenser is maximized within the first preset time length or the second preset time length, so as to facilitate the subsequent bringing out of the lubricating oil on the pipe wall when the pressure is released.

[0061] Specifically, in the refrigeration mode, the first pipes in the evaporator are controlled to be alternately conducted as follows: the controller controls any one of the M first electromagnetic valves to be conducted, so that the first pipe corresponding to the any one of the M first electromagnetic valves is conducted, and the other (M-1) first pipes are closed; then, after a first preset time interval, any one of the other (M-1) first electromagnetic valves is controlled to be conducted, and the any one of the M first electromagnetic valves that is conducted last time is controlled to be closed, and the other (M-2) first electromagnetic valves are closed; after the conductive time of each first electromagnetic valve reaches the first preset time, the first electromagnetic valve that is currently conducted is closed, and another first electromagnetic valve is conducted. Thus, the pipe pressure of the evaporator is maximized within the first preset time, so that the lubricating oil on the pipe wall can be fully brought out when the pressure is released subsequently.

[0062] In the heating mode, the second pipes in the condenser are controlled to be alternately conducted as follows: the controller controls any one of the N second electromagnetic valves to be conducted, so that the second pipe corresponding to the any one of the N second electromagnetic valves is conducted, and the other (N-1) second pipes are closed; then, after a second preset time interval, any one of the other (N-1) second electromagnetic valves is controlled to be conducted, and the any one of the N second electromagnetic valves that is conducted last time is controlled to be closed, and the other (N-2) second electromagnetic valves are closed; after the conductive time of each second electromagnetic valve reaches the second preset time, the second electromagnetic valve that is currently conducted is closed, and another second electromagnetic valve is conducted. Thus, the pipe pressure of the condenser is maximized within the second preset time, so that the lubricating oil on the pipe wall can be fully brought out when the pressure is released subsequently.

[0063] In some embodiments, the first preset time and the second preset time can be set in advance according to actual conditions, and the first preset time and the second preset time can be the same or different, which is not limited. For example, the first preset time and the second preset time are both 30s.

[0064] In some embodiments, the controller is further configured to, when the M first electromagnetic valves are controlled to be alternately conducted, control the last conducted first electromagnetic valve to be closed after the conductive time of the currently conducted first electromagnetic valve reaches a third preset time, that is, after a certain first electromagnetic valve is controlled to be conducted, the last conducted first electromagnetic valve is not directly controlled to be closed, but the two first electromagnetic valves are controlled to be conducted simultaneously for the third preset time, and then the last conducted first electromagnetic valve is controlled to be closed, which is beneficial to slowly recover the system pressure and ensure the pressure balance of the air conditioning compressor.

[0065] And, when controlling the N second electromagnetic valves to be turned on alternately, after the on duration of the currently turned-on second electromagnetic valve reaches a fourth preset duration, the last turned-on second electromagnetic valve is controlled to be turned off, that is, after a certain second electromagnetic valve is controlled to be turned on, instead of directly controlling the last turned-on second electromagnetic valve to be turned off, the two second electromagnetic valves are controlled to be turned on simultaneously for the fourth preset duration, and then the last turned-on second electromagnetic valve is controlled to be turned off, thereby facilitating slow recovery of the system pressure and ensuring pressure balance of the air conditioning unit.

[0066] In some embodiments, the third preset duration and the fourth preset duration can be preset according to actual conditions, and the third preset duration and the fourth preset duration can be the same or different, which is not limited. For example, the third preset duration and the fourth preset duration are both 15s.

[0067] In some embodiments, the controller is further configured to: prohibit the air conditioner from responding to other function instructions, such as low pressure protection instructions, exhaust temperature detection, and the like, until the air conditioner meets the oil return control end condition, and then control the air conditioner to return to a normal operating state. That is, after meeting the oil return control condition, the air conditioner will forcibly run the above oil return control process and will not be interrupted due to triggering of other function instructions, thereby giving priority to the problems of compressor oil return and tripping protection and improving user experience.

[0068] In some embodiments, the oil return control end condition can be set according to actual conditions such as oil return conditions, oil return duration, and the like, which is not limited. For example, the oil return control end condition can include that each first electromagnetic valve or each second electromagnetic valve completes one on-off operation.

[0069] The specific process is described below with reference to FIGS. 1-6, which show an air conditioning unit including six first pipelines and six second pipelines, and the air conditioning unit is in a refrigeration mode. Figure 7 、 Figure 8 and Figure 9 For example, the six first electromagnetic valves 51 are first electromagnetic valve 511, first electromagnetic valve 512, first electromagnetic valve 513, first electromagnetic valve 514, first electromagnetic valve 515, and first electromagnetic valve 516.

[0070] Step S4: When the air conditioning unit meets the oil return control condition, the first electromagnetic valve 511 is opened, the first electromagnetic valve 512, the first electromagnetic valve 513, the first electromagnetic valve 514, the first electromagnetic valve 515, and the first electromagnetic valve 516 are all closed, the outdoor unit electromagnetic valve is kept open, that is, all the second electromagnetic valves 52 in the condenser are turned on, the compressor is raised to a frequency of 80HZ, and is stably operated for a first preset duration of 30s, the system exhaust temperature, low pressure protection, and the like are not determined, and the air conditioning unit is forcibly operated, thereby increasing the pressure of the evaporator pipeline as much as possible.

[0071] Step S5, then, the first solenoid valve 512 open third preset duration 3s after the first solenoid valve 511, the first solenoid valve 513, the first solenoid valve 514, the first solenoid valve 515 and the first solenoid valve 516 remain unchanged, outdoor unit solenoid valve remains open circuit, the compressor frequency increases 80HZ, and stable operation of the first preset duration 30s, system exhaust temperature, low pressure protection, etc. not to determine, air conditioner forced operation, thus the refrigerant as far as possible to increase the evaporator line pressure, while the first solenoid valve 512 open instant pressure release, refrigerant gas flow faster, can bring out more fully the lubricating oil of the pipe wall.

[0072] Step S6, then, the first solenoid valve 513 open third preset duration 3s after the first solenoid valve 512, the first solenoid valve 511, the first solenoid valve 514, the first solenoid valve 515 and the first solenoid valve 516 remain unchanged, outdoor unit solenoid valve remains open circuit, the compressor frequency increases 80HZ, and stable operation of the first preset duration 30s, system exhaust temperature, low pressure protection, etc. not to determine, air conditioner forced operation, thus the refrigerant as far as possible to increase the evaporator line pressure, while the first solenoid valve 513 open instant pressure release, refrigerant gas flow faster, can bring out more fully the lubricating oil of the pipe wall.

[0073] Step S7, then, the first solenoid valve 514 open third preset duration 3s after the first solenoid valve 513, the first solenoid valve 511, the first solenoid valve 512, the first solenoid valve 515 and the first solenoid valve 516 remain unchanged, outdoor unit solenoid valve remains open circuit, the compressor frequency increases 80HZ, and stable operation of the first preset duration 30s, system exhaust temperature, low pressure protection, etc. not to determine, air conditioner forced operation, thus the refrigerant as far as possible to increase the evaporator line pressure, while the first solenoid valve 514 open instant pressure release, refrigerant gas flow faster, can bring out more fully the lubricating oil of the pipe wall.

[0074] Step S8, then, the first solenoid valve 515 open third preset duration 3s after the first solenoid valve 514, the first solenoid valve 511, the first solenoid valve 512, the first solenoid valve 513 and the first solenoid valve 516 remain unchanged, outdoor unit solenoid valve remains open circuit, the compressor frequency increases 80HZ, and stable operation of the first preset duration 30s, system exhaust temperature, low pressure protection, etc. not to determine, air conditioner forced operation, thus the refrigerant as far as possible to increase the evaporator line pressure, while the first solenoid valve 515 open instant pressure release, refrigerant gas flow faster, can bring out more fully the lubricating oil of the pipe wall.

[0075] In step S9, after the first solenoid valve 516 is opened for a third preset time of 3 seconds, the first solenoid valve 515 closes. The first solenoid valves 511, 512, 513, and 514 remain unchanged. The outdoor unit solenoid valve remains open. The compressor increases its frequency to 80 Hz and runs stably for a first preset time of 30 seconds. The system exhaust temperature and low pressure protection are not determined. The air conditioner is forced to run, thereby increasing the pressure of the evaporator pipe as much as possible. At the same time, the pressure is released the instant the first solenoid valve 516 opens, and the refrigerant gas flow rate is faster, which can carry out the lubricating oil on the pipe wall more fully.

[0076] In step S10, the first solenoid valve 516 opens, and then the first solenoid valves 511, 512, 513, 514, and 515 open sequentially every 15 seconds, thereby slowly restoring the system load pressure to normal. At this point, each first solenoid valve 51 has completed one conduction cycle, satisfying the oil return control termination condition, and the air conditioner returns to normal operation.

[0077] Similarly, refer to Figure 10 As shown, when the air conditioner is in heating mode, and the air conditioner meets the oil return control conditions, all the first solenoid valves 51 in the evaporator are turned on. The control method for turning on the second solenoid valves 52 in the condenser alternately is the same as the oil return control steps in the cooling mode, and will not be described in detail here.

[0078] A second aspect of the present invention provides a control method for an air conditioner, used in the air conditioner of the above embodiment, the control method comprising at least steps S1-S3.

[0079] Step S1: Determine that the air conditioner meets the oil return control conditions.

[0080] Specifically, considering that the air conditioner in this application uses a diesel generator, and taking into account the maximum current limitation of the diesel generator, in order to avoid the problems of compressor oil shortage and power trip protection, the oil return control conditions are preset according to the actual situation, and step S2 or step S3 is executed when the oil return control conditions are met; while the air conditioner still maintains normal operation when the oil return control conditions are not met.

[0081] In some embodiments, considering the problem that prolonged low-frequency operation of the air conditioner may cause compressor oil shortage and thus compressor wear, this application sets oil return control conditions based on the compressor's operating time. The specific oil return control conditions include at least the compressor's operating time reaching a fifth preset duration, thereby avoiding prolonged low-frequency operation of the compressor.

[0082] The fifth preset duration is set based on actual conditions such as compressor specifications and is not subject to any restrictions. For example, the fifth preset duration can be 180 minutes.

[0083] In some embodiments, to avoid the problem of compressor oil shortage, additional oil return control conditions, such as pipeline temperature, can be added according to actual needs for determination, and there are no restrictions on this.

[0084] Step S2: If the air conditioner is in cooling mode, control multiple second solenoid valves to be fully open and control M first solenoid valves to be alternately open so that multiple first pipelines are alternately open.

[0085] Specifically, refer to Figure 1 As shown, in cooling mode, all second pipes of the condenser are fully open, while the first pipes in the evaporator are alternately open. That is, the controller first opens only one of the M first pipes, while the other (M-1) first pipes are closed; then it opens any one of the other (M-1) first pipes, while the previously opened first pipe closes again, and the other (M-2) first pipes close as well. This cycle repeats. Therefore, by adding a first solenoid valve to the first pipe of the evaporator to control the refrigerant flow, when the compressor runs at increased frequency, since all (M-1) first pipes are closed at the same time, as the pressure increases... As the compressor frequency increases and the pressure rises, the refrigerant accumulates in the first pipe (M-1) of the evaporator, thus reducing the amount of refrigerant circulating in the entire refrigerant circuit. Therefore, although the compressor frequency increases, the reduced refrigerant circulation lowers the compressor load, resulting in a faster refrigerant flow rate throughout the circuit. This also brings the lubricating oil back to the compressor, achieving oil return. Simultaneously, the reduced refrigerant circulation also lowers the overall operating current. Therefore, even if the compressor frequency increases, the change in overall operating current will be minimal, achieving the goal of increasing frequency without exceeding current limits. This avoids the problem of users being unable to use the machine due to power outages and improves the user experience.

[0086] Step S3: If the air conditioner is in heating mode, control multiple first solenoid valves to be fully open and control N second solenoid valves to be alternately open so that multiple second pipelines are alternately open.

[0087] Specifically, refer to Figure 1As shown, in heating mode, all the first pipes of the evaporator are fully open, while the second pipes in the condenser are alternately open. That is, the controller first opens only one of the N second pipes, while the other (N-1) second pipes are closed; then it opens one of the other (N-1) second pipes, and closes the previously opened second pipe, while closing the other (N-2) second pipes, and so on in a cyclical alternation. Therefore, by adding a second solenoid valve to the second pipes of the condenser to control the refrigerant flow, when the compressor runs at increased frequency, since all (N-1) second pipes are closed at the same time, as the pressure increases... As the compressor frequency increases and the pressure rises, the refrigerant accumulates in the (N-1)th second pipe of the condenser, thereby reducing the amount of refrigerant circulating in the entire refrigerant circuit. Therefore, although the compressor frequency increases, the load on the compressor decreases due to the reduced refrigerant circulation, resulting in a faster refrigerant flow rate in the entire refrigerant circuit. This also brings the lubricating oil back to the compressor, achieving oil return. At the same time, the reduced refrigerant circulation also reduces the overall operating current. Therefore, even if the compressor frequency increases, the change in the overall operating current will be very small, thus achieving the goal of increasing the frequency without exceeding the current limit. This avoids the problem of users being unable to use the machine due to power outages and improves the user experience.

[0088] According to the control method of the air conditioner according to the embodiment of the present invention, a solenoid valve is added to each pipe of the evaporator and each pipe of the condenser. By controlling the conduction of each solenoid valve, only one pipe of the evaporator or condenser is opened in different operating modes of the air conditioner. As a result, when the compressor frequency is increased, the refrigerant accumulates in the condenser or evaporator, thereby reducing the amount of refrigerant circulating in the entire refrigerant circuit, reducing the compressor load, increasing the refrigerant flow rate, and realizing compressor oil return. At the same time, because the amount of refrigerant circulating is reduced, the overall operating current of the unit is also reduced synchronously. Therefore, even if the compressor frequency is increased, the change in the overall operating current will be very small, thereby achieving the purpose of increasing the frequency without the current not exceeding the limit requirement, avoiding the problem of users being unable to use the air conditioner due to power outages, and improving the user experience.

[0089] In some embodiments, the control method further includes: when controlling M first solenoid valves to alternately conduct, controlling the conduction time of each first solenoid valve to reach a first preset time; and when controlling N second solenoid valves to alternately conduct, controlling the conduction time of each second solenoid valve to reach a second preset time. This maximizes the increase in the pipeline pressure of the evaporator or condenser within the first or second preset time, so that the lubricating oil on the pipe wall can be fully carried out during subsequent pressure release.

[0090] Specifically, in the refrigeration mode, the first pipeline in the evaporator is controlled to be alternately conducted, specifically: the controller controls any one of the M first electromagnetic valves to be conducted, so that the first pipeline corresponding to the any one of the M first electromagnetic valves is conducted, and the other (M-1) first pipelines are closed; then, after a first preset time interval, any one of the other (M-1) first electromagnetic valves is controlled to be conducted, and the any one of the first electromagnetic valves that is conducted last time is closed and the other (M-2) first electromagnetic valves are closed; after the control of the conduction time of each first electromagnetic valve reaches the first preset time, the currently conducted first electromagnetic valve is closed and another first electromagnetic valve is conducted. Thus, the pipeline pressure of the evaporator is maximized within the first preset time, so that the lubricating oil on the pipe wall can be fully brought out when the pressure is released subsequently.

[0091] In the heating mode, the second pipeline in the condenser is controlled to be alternately conducted, specifically: the controller controls any one of the N second electromagnetic valves to be conducted, so that the second pipeline corresponding to the any one of the N second electromagnetic valves is conducted, and the other (N-1) second pipelines are closed; then, after a second preset time interval, any one of the other (N-1) second electromagnetic valves is controlled to be conducted, and the any one of the second electromagnetic valves that is conducted last time is closed and the other (N-2) second electromagnetic valves are closed; after the control of the conduction time of each second electromagnetic valve reaches the second preset time, the currently conducted second electromagnetic valve is closed and another second electromagnetic valve is conducted. Thus, the pipeline pressure of the condenser is maximized within the second preset time, so that the lubricating oil on the pipe wall can be fully brought out when the pressure is released subsequently.

[0092] In some embodiments, the control method further comprises: when the M first electromagnetic valves are controlled to be alternately conducted, after the conduction time of the currently conducted first electromagnetic valve reaches a third preset time, the last conducted first electromagnetic valve is controlled to be closed, that is, after a certain first electromagnetic valve is controlled to be conducted, the last conducted first electromagnetic valve is not directly controlled to be closed, but the two first electromagnetic valves are controlled to be conducted simultaneously for the third preset time, and then the last conducted first electromagnetic valve is controlled to be closed, thereby facilitating slow recovery of the system pressure and ensuring pressure balance of the air conditioner.

[0093] In addition, when the N second electromagnetic valves are controlled to be alternately conducted, after the conduction time of the currently conducted second electromagnetic valve reaches a fourth preset time, the last conducted second electromagnetic valve is controlled to be closed, that is, after a certain second electromagnetic valve is controlled to be conducted, the last conducted second electromagnetic valve is not directly controlled to be closed, but the two second electromagnetic valves are controlled to be conducted simultaneously for the fourth preset time, and then the last conducted second electromagnetic valve is controlled to be closed, thereby facilitating slow recovery of the system pressure and ensuring pressure balance of the air conditioner.

[0094] In some embodiments, the controller is further configured to: prohibit the air conditioner from responding to other function instructions, such as low pressure protection instructions, discharge temperature detection, and the like, until the air conditioner meets the oil return control end condition, and then control the air conditioner to return to a normal operation state. That is, after the oil return control condition is met, the air conditioner will forcibly run the oil return control process, and will not be interrupted due to triggering of other function instructions, thereby giving priority to the problems of compressor oil return and tripping protection, and improving user experience.

[0095] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example.

[0096] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. An air conditioner characterized by comprising: Comprises: A compressor; An evaporator comprising M first pipelines; A condenser comprising N second pipelines; X electromagnetic valves, X electromagnetic valves comprising M first electromagnetic valves and N second electromagnetic valves, each first electromagnetic valve is correspondingly arranged on each first pipeline, the first electromagnetic valve is used to turn on or turn off the corresponding first pipeline, each second electromagnetic valve is correspondingly arranged on each second pipeline, and the second electromagnetic valve is used to turn on or turn off the corresponding second pipeline; A refrigerant circuit, which circulates refrigerant in the compressor, the evaporator, a throttle valve, and the condenser; A controller configured to, if the air conditioner meets an oil return control condition, If the air conditioner is in a cooling mode, control a plurality of second electromagnetic valves to be fully turned on, and control M first electromagnetic valves to be alternately turned on, so as to alternately turn on the plurality of first pipelines; If the air conditioner is in a heating mode, control a plurality of first electromagnetic valves to be fully turned on, and control N second electromagnetic valves to be alternately turned on, so as to alternately turn on the plurality of second pipelines.

2. The air conditioner of claim 1, wherein The controller is further configured to: When controlling the M first electromagnetic valves to be alternately turned on, control the on duration of each first electromagnetic valve to reach a first preset duration; When controlling the N second electromagnetic valves to be alternately turned on, control the on duration of each second electromagnetic valve to reach a second preset duration.

3. The air conditioner according to claim 1 or 2, characterized by The controller is further configured to: When controlling the M first electromagnetic valves to be alternately turned on, after the on duration of the currently turned-on first electromagnetic valve reaches a third preset duration, control the last turned-on first electromagnetic valve to be turned off; When controlling the N second electromagnetic valves to be alternately turned on, after the on duration of the currently turned-on second electromagnetic valve reaches a fourth preset duration, control the last turned-on second electromagnetic valve to be turned off.

4. The air conditioner of claim 1, wherein The oil return control condition at least includes: The running duration of the compressor reaches a fifth preset duration.

5. The air conditioner of claim 1, wherein The controller is further configured to: Inhibit the air conditioner from responding to other function instructions; Until the air conditioner meets an oil return control end condition, control the air conditioner to return to a normal running state.

6. A control method of an air conditioner, characterized by, The control method for the air conditioner of any one of claims 1-5, the control method comprising: If the air conditioner meets an oil return control condition, If the air conditioner is in a cooling mode, control a plurality of second electromagnetic valves to be fully turned on, and control M first electromagnetic valves to be alternately turned on, so as to alternately turn on the plurality of first pipelines; If the air conditioner is in a heating mode, control a plurality of first electromagnetic valves to be fully turned on, and control N second electromagnetic valves to be alternately turned on, so as to alternately turn on the plurality of second pipelines.

7. The control method of the air conditioner according to claim 6, characterized by, The control method further comprises: When controlling the M first electromagnetic valves to be alternately turned on, control the on duration of each first electromagnetic valve to reach a first preset duration; When controlling the N second electromagnetic valves to be alternately turned on, control the on duration of each second electromagnetic valve to reach a second preset duration.

8. The control method of an air conditioner according to claim 6 or 7, characterized by, The control method further comprises: When controlling the M first electromagnetic valves to be alternately turned on, after the on duration of the currently turned-on first electromagnetic valve reaches a third preset duration, control the last turned-on first electromagnetic valve to be turned off; When the N second electromagnetic valves are controlled to be turned on alternately, after the on duration of the currently turned-on second electromagnetic valve reaches a fourth preset duration, the last turned-on second electromagnetic valve is controlled to be turned off.

9. The control method of the air conditioner according to claim 6, wherein The oil return control condition at least includes: The operation duration of the compressor reaches a fifth preset duration.

10. The control method of the air conditioner according to claim 6, characterized by, The control method further includes: Inhibiting the air conditioner from responding to other function instructions; Until the air conditioner meets the oil return control end condition, the air conditioner is controlled to return to a normal operation state.

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