Track fixed-frequency air conditioner and control method thereof

Abstract

The invention provides a track fixed-frequency air conditioner which comprises a refrigerating circuit, a control circuit and a control circuit. The refrigerating circuit comprises at least two compressors. And the control module is used for judging the starting and stopping number of the compressors according to the outdoor temperature Tout, the indoor temperature Tin and the set temperature in the refrigeration mode. The control module can judge the starting and stopping number of the compressor based on the outdoor temperature Tout, the indoor temperature Tin and the set temperature, the evaporation temperature is increased by reducing refrigeration load output, and the situation that the evaporator is frozen is avoided; and on the other hand, due to the fact that the refrigeration load is reduced, the air supply temperature at the air supply outlet is high, and the comfort of passengers is guaranteed. The invention further provides a track fixed-frequency air conditioner control method adopting the track fixed-frequency air conditioner.

Description

Technical Field

[0001] The present invention belongs to the technical field of rail air conditioners, and in particular relates to a rail fixed-frequency air conditioner and a control method thereof. Background Art

[0002] The refrigerant in the air-conditioning system absorbs heat and evaporates at the evaporator, which may cause the evaporation temperature to be low and the evaporator to freeze.

[0003] In the existing technology, the evaporation temperature is increased by reducing the number of running condensing fans. However, since it is necessary to control the number of starts and stops of the condensing fans, a contactor needs to be independently set for each condensing fan when arranging the electrical circuit, which increases the production cost. On the other hand, although deactivating the condensing fan will increase the evaporation temperature, the compressor is still outputting at full load at this time, and the evaporation pressure is still lower than the rated operating conditions. At this time, it may cause difficulty in oil return of the compressor, affecting the service life of the compressor.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] One purpose of the present invention is to overcome the shortcomings of the prior art and provide a track constant-frequency air conditioner, in which the control module can control the number of starts and stops of the compressor based on the outdoor temperature Tout, the indoor temperature Tin and the set temperature, thereby increasing the evaporation temperature and avoiding evaporator freezing.

[0006] Another object of the present invention is to provide a method for controlling an orbital fixed-frequency air conditioner using the above-mentioned orbital fixed-frequency air conditioner.

[0007] In order to achieve the first object of the invention, the present invention adopts the following technical solutions:

[0008] A track fixed-frequency air conditioner, comprising:

[0009] a refrigeration circuit comprising at least two compressors;

[0010] The control module is used to determine the number of compressor starts and stops according to the outdoor temperature Tout, indoor temperature Tin and set temperature in cooling mode.

[0011] Furthermore, the set temperature includes a first set temperature T1 and a second set temperature Ts, and the control module determines the number of compressor starts and stops based on the relationship between the outdoor temperature Tout and the first set temperature T1 and the difference between the indoor temperature Tin and the second set temperature Ts.

[0012] Furthermore, the first set temperature T1 is determined by the outdoor temperature Tout at which the evaporator freezes when all compressors are running.

[0013] In order to achieve the second object of the invention, the present invention adopts the following technical solution:

[0014] A method for controlling a track fixed-frequency air conditioner adopts the above-mentioned track fixed-frequency air conditioner.

[0015] Further, including:

[0016] In cooling mode, determining whether the outdoor temperature Tout meets the first set condition, and if so, reducing the number of operating compressors;

[0017] If not, keep the current number of running compressors.

[0018] Furthermore, the first setting condition is that the outdoor temperature Tout is less than or equal to the first setting temperature T1.

[0019] Furthermore, when the outdoor temperature Tout satisfies the first setting condition, it is determined at each set time interval whether the indoor temperature Tin satisfies the second setting condition. If so, the number of running compressors is increased;

[0020] If not, keep the current number of running compressors.

[0021] Furthermore, the second setting condition is that the difference between the indoor temperature Tin and the second set temperature Ts is greater than or equal to the first set value.

[0022] Furthermore, when the indoor temperature Tin meets the second setting condition, it is determined whether the difference between the indoor temperature Tin and the second set temperature Ts is less than or equal to the second set value. If so, the number of running compressors is reduced;

[0023] If not, keep the current number of running compressors;

[0024] The second set value is smaller than the first set value.

[0025] Furthermore, it is characterized in that the increasing the number of running compressors is based on the current number of running compressors plus one;

[0026] The reducing the number of operating compressors is performed by subtracting one from the current number of operating compressors.

[0027] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0028] 1. The control module of the present invention can determine the number of compressor starts and stops based on the outdoor temperature Tout, the indoor temperature Tin, and the set temperature. By reducing the cooling load output, the evaporation temperature is increased to avoid evaporator icing. On the other hand, due to the reduced cooling load, the air supply temperature at the air supply outlet is higher, thereby ensuring passenger comfort.

[0029] 2. The present invention determines whether to increase the number of operating compressors by judging whether the indoor temperature Tin meets the second set condition. Under the premise of ensuring the comfort in the passenger room, a smaller number of compressors can be activated to reduce the cooling load, increase the evaporation temperature, and avoid evaporator freezing. On the other hand, when the indoor temperature Tin is high, the comfort in the passenger room can be improved by promptly increasing the number of operating compressors and increasing the cooling output in the passenger room.

[0030] 3. When the indoor temperature Tin meets the second set condition, the present invention further determines the number of starts and stops of the compressor by judging whether the difference between the indoor temperature Tin and the second set temperature Ts is less than or equal to the second set value. Under the premise of ensuring the comfort in the passenger compartment, the number of running compressors is adjusted in time to avoid evaporator freezing due to too low evaporation temperature.

[0031] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an undue limitation of the present invention. Obviously, the drawings described below are only some embodiments. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without inventive effort. In the accompanying drawings:

[0033] Figure 1 It is a flow chart of the track fixed-frequency air conditioning control method of the present invention;

[0034] Figure 2 It is a schematic diagram of a track fixed-frequency air conditioning control method in an embodiment of the present invention in which two compressors are provided.

[0035] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but rather to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0037] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0038] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0039] In air conditioning systems, the refrigerant absorbs heat and evaporates in the evaporator. However, in low-temperature conditions, this heat absorption can cause the evaporator to freeze. Existing technologies reduce the number of operating condensing fans to reduce the amount of heat absorbed by the refrigerant in the evaporator, thereby increasing the evaporation temperature and preventing evaporator freezing. However, this requires a separate contactor for each condensing fan, increasing production costs.

[0040] In view of this, the present invention provides a track fixed-frequency air conditioner, comprising:

[0041] a refrigeration circuit comprising at least two compressors;

[0042] The control module is used to determine the number of compressor starts and stops according to the outdoor temperature Tout, indoor temperature Tin and set temperature in cooling mode.

[0043] Specifically, in the present invention, when the outdoor temperature Tout is high, on the one hand, more compressors are required to work to ensure the cooling output, thereby ensuring indoor comfort. On the other hand, due to the high ambient temperature, even if the refrigerant absorbs heat at the evaporator, the evaporator can be avoided from freezing. At this time, the control module can control the activation of more compressors.

[0044] When the outdoor temperature Tout is low, fewer compressors need to be activated. On the one hand, due to the low outdoor temperature Tout, fewer compressors can meet the indoor cooling output. On the other hand, when fewer compressors are working, it can also prevent the refrigerant from absorbing too much heat at the evaporator, causing the evaporator to freeze.

[0045] Furthermore, when the outdoor temperature Tout is low but the indoor temperature Tin is high, that is, when the difference between the indoor temperature Tin and the set temperature is large, more compressors are still required to work to ensure indoor comfort and passenger experience.

[0046] Therefore, the set temperature in the present invention includes a first set temperature T1 and a second set temperature T2, wherein the first set temperature T1 is compared with the outdoor temperature Tout, and the second set temperature T2 is compared with the indoor temperature Tin. The control module determines the number of starts and stops of the compressor based on the relationship between the outdoor temperature Tout and the first set temperature T1 and the difference between the indoor temperature Tin and the second set temperature Ts.

[0047] In one embodiment of the present invention, the first set temperature T1 is determined by the outdoor temperature Tout at which the evaporator is frozen when all compressors are operating.

[0048] For example, if there are two compressors in the refrigeration circuit, the outdoor temperature Tout at which the evaporator freezes when both compressors are running is determined as the first set temperature T1.

[0049] like Figure 1-2 As shown, the present invention also provides a method for controlling a track fixed-frequency air conditioner using the above track fixed-frequency air conditioner, comprising:

[0050] In cooling mode, determining whether the outdoor temperature Tout meets the first set condition, and if so, reducing the number of operating compressors;

[0051] If not, keep the current number of running compressors.

[0052] In one embodiment of the present invention, the first set condition is that the outdoor temperature Tout is less than or equal to the first set temperature T1.

[0053] Therefore, when the outdoor temperature Tout meets the first setting condition, that is, when the outdoor temperature Tout is less than or equal to the first setting temperature T1, it indicates that the ambient temperature is low at this time, and fewer compressors can meet the indoor cooling demand, and the number of running compressors can be appropriately reduced.

[0054] When the outdoor temperature Tout does not meet the first setting condition, that is, when the outdoor temperature Tout is greater than the first set temperature T1, it indicates that the ambient temperature is relatively high. In order to ensure indoor comfort, the cooling output needs to be guaranteed, and the number of running compressors needs to be guaranteed.

[0055] Furthermore, in this embodiment, reducing the number of operating compressors is based on the current number of operating compressors minus one.

[0056] For example, Figure 2As shown, when there are two compressors in the refrigeration circuit, in order to ensure the cooling output, the initial number of running compressors is two, that is, all compressors are running simultaneously in the initial state.

[0057] If the outdoor temperature Tout is less than or equal to the first set temperature T1, the number of compressors in operation is reduced from two to one, that is, a single compressor is in operation;

[0058] If the outdoor temperature Tout is greater than the first set temperature T1, in order to ensure indoor comfort, the dual compressors are kept running.

[0059] In another embodiment of the present invention, when the outdoor temperature Tout satisfies the first set condition, it is determined at every set time interval whether the indoor temperature Tin satisfies the second set condition. If so, the number of operating compressors is increased.

[0060] If not, keep the current number of running compressors.

[0061] The second setting condition is that the difference between the indoor temperature Tin and the second set temperature Ts is greater than or equal to the first set value.

[0062] Specifically, when the outdoor temperature Tout meets the first set condition, the difference between the indoor temperature Tin and the second set temperature Ts is determined at each set time interval to determine whether it is greater than or equal to the first set value. If so, it indicates that the indoor temperature Tin is too high and passenger comfort cannot be guaranteed. In this case, the number of running compressors needs to be increased to increase the cooling output.

[0063] If not, it indicates that the current indoor temperature Tin can ensure the comfort of the passengers, so the current number of running compressors is maintained.

[0064] Preferably, the set time can be set to 3 minutes, that is, the indoor temperature Tin is judged every 3 minutes to see whether it meets the second set condition. This can not only avoid frequent start and stop of the compressor, but also timely adjust the indoor temperature Tin by controlling the start and stop of the compressor to ensure the comfort of the passengers.

[0065] Further preferably, when the difference between the indoor temperature Tin and the second set temperature Ts is greater than or equal to the first set value, the number of running compressors is increased by one based on the current number of running compressors.

[0066] For example, Figure 2 As shown, when there are two compressors in the refrigeration circuit, it is determined whether the outdoor temperature Tout is less than or equal to the first set temperature T1. If not, it indicates that the outdoor temperature Tout is high, and the dual compressors are operated to ensure the indoor cooling output;

[0067] If so, it indicates that the number of running compressors can be appropriately reduced. While ensuring the indoor cooling output, the evaporator can also be prevented from freezing. At this time, the number of running compressors can be reduced and only one compressor can be operated.

[0068] The outdoor temperature Tout is less than or equal to the first set temperature T1. At each set time interval, it is further determined whether the difference between the indoor temperature Tin and the second set temperature Ts is greater than or equal to the first set value. If so, it indicates that the indoor temperature Tin is high at this time. In order to ensure the comfort of the passengers, the number of running compressors needs to be increased to increase the cooling output. At this time, the number of running compressors is increased by one based on the single compressor operation, that is, it is adjusted to dual compressor operation.

[0069] If not, it indicates that the indoor temperature Tin is more suitable at this time, and the current number of running compressors is maintained, that is, a single compressor is maintained in operation.

[0070] Preferably, the first set value is 3°C.

[0071] In another embodiment of the present invention, when the indoor temperature Tin satisfies the second set condition, after increasing the number of operating compressors, it is further determined whether the difference between the indoor temperature Tin and the second set temperature Ts is less than or equal to the second set value. If so, it indicates that the indoor temperature Tin is relatively comfortable at this time, and to prevent evaporator icing, the number of operating compressors can be reduced.

[0072] If not, it indicates that the indoor temperature Tin needs to be adjusted, and the current number of running compressors is maintained.

[0073] The second set value is smaller than the first set value, and the second set value is preferably 1°C.

[0074] When the difference between the indoor temperature Tin and the second set temperature Ts is adjusted from greater than or equal to the first set value to less than or equal to the second set value, it means that after increasing the number of running compressors, the indoor temperature Tin is adjusted to a range that is more comfortable for the passengers. At this time, in order to avoid evaporator freezing and to increase the supply air temperature to further improve passenger comfort, the number of running compressors can be appropriately reduced.

[0075] For example, Figure 2 As shown, the refrigeration circuit includes two compressors. When the difference between the indoor temperature Tin and the second set temperature Ts is greater than or equal to the first set value, after increasing the number of operating compressors, it is further determined whether the difference between the indoor temperature Tin and the second set temperature Ts is less than or equal to the second set value. If so, in order to avoid evaporator icing, the operation is adjusted to a single compressor.

[0076] If not, keep the dual compressors running to ensure cooling output in the passenger compartment for passenger comfort.

[0077] Therefore, the control module in the present invention determines the number of starts and stops of the compressor based on the outdoor temperature Tout, the indoor temperature Tin and the set temperature. It can increase the evaporation temperature by reducing the refrigeration load output to avoid the evaporator from freezing. On the other hand, since the refrigeration load is reduced, the comfort of the passengers in the passenger compartment can also be improved by increasing the supply air temperature.

[0078] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with this patent can make slight changes or modifications to equivalent embodiments of equivalent changes using the above-mentioned technical contents without departing from the scope of the technical solution of the present invention. The implementation schemes in the above-mentioned embodiments can also be further combined or replaced. However, any simple modifications, equivalent changes and modifications made to the above-mentioned embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the solution of the present invention.

Claims

1. A track fixed frequency air conditioner, characterized in that: include: a refrigeration circuit comprising at least two compressors; The control module is used to determine the number of compressor starts and stops according to the outdoor temperature Tout, indoor temperature Tin and set temperature in cooling mode.

2. The track fixed-frequency air conditioner according to claim 1, characterized in that: The set temperatures include a first set temperature T1 and a second set temperature Ts. The control module determines the number of compressor starts and stops based on the relationship between the outdoor temperature Tout and the first set temperature T1 and the difference between the indoor temperature Tin and the second set temperature Ts.

3. The track fixed-frequency air conditioner according to claim 2, characterized in that: The first set temperature T1 is determined by the outdoor temperature Tout at which the evaporator freezes when all compressors are running.

4. A method for controlling a track fixed-frequency air conditioner, characterized in that: The track fixed-frequency air conditioner according to any one of claims 1 to 3 is adopted.

5. A method for controlling an orbital fixed-frequency air conditioner according to claim 4, characterized in that: include: In cooling mode, determining whether the outdoor temperature Tout meets the first set condition, and if so, reducing the number of operating compressors; If not, keep the current number of running compressors.

6. A method for controlling an orbital fixed-frequency air conditioner according to claim 5, characterized in that: The first setting condition is that the outdoor temperature Tout is less than or equal to the first setting temperature T1.

7. The method for controlling an orbital fixed-frequency air conditioner according to claim 5, characterized in that: When the outdoor temperature Tout meets the first setting condition, it is determined at every set time whether the indoor temperature Tin meets the second setting condition. If so, the number of running compressors is increased; If not, keep the current number of running compressors.

8. The method for controlling an orbital fixed-frequency air conditioner according to claim 7, characterized in that: The second setting condition is that the difference between the indoor temperature Tin and the second set temperature Ts is greater than or equal to the first set value.

9. The method for controlling an orbital fixed-frequency air conditioner according to claim 7, characterized in that: When the indoor temperature Tin meets the second setting condition, it is determined whether the difference between the indoor temperature Tin and the second set temperature Ts is less than or equal to the second set value. If so, the number of running compressors is reduced; If not, keep the current number of running compressors; The second set value is smaller than the first set value.

10. A method for controlling an orbital fixed-frequency air conditioner according to any one of claims 7 to 9, characterized in that: The increasing the number of running compressors is based on the current number of running compressors plus one; The reducing the number of operating compressors is performed by subtracting one from the current number of operating compressors.

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