Direct expansion type air conditioning unit with automatic defrosting function

Abstract

The utility model discloses a direct expansion type air conditioning unit with an automatic defrosting function. The direct expansion type air conditioning unit comprises an outdoor unit, an indoor unit and a compressor, the outdoor unit comprises a machine shell. The shell is provided with a plurality of groups of infrared correlation probe groups; each group of the infrared correlation probe groups comprises an emitter and a receiver; the transmitters and the receivers are in one-to-one correspondence in position and are located on the wind receiving face of the machine shell. According to the utility model, a plurality of infrared correlation probe groups are adopted to detect the thickness of a frost layer, so that the problem that a single probe group is possibly triggered by mistake due to blocking of sundries is effectively avoided, and meanwhile, the problem that defrosting cannot be triggered in time due to insufficient number of probe groups is also solved.

Description

Technical Field

[0001] The utility model relates to a direct expansion air conditioner unit with an automatic defrosting function, belonging to the technical field of air conditioning. Background Art

[0002] As Figure 3 shown, a typical direct expansion air conditioner unit (referred to as an air conditioner unit for short) includes an outdoor unit (condenser), an indoor unit (evaporator), and a compressor. Through an electronic expansion valve and a filter, a working medium (refrigerant) forms a loop between a liquid receiver and an evaporator to circulate for refrigeration. Among them, the outdoor unit includes components such as a compressor, a condenser, and a fan, which are responsible for transferring the heat indoors to the outdoors. The condenser is located in the outdoor unit and is the place where the refrigerant releases heat and changes from a gaseous state to a high-pressure liquid state. The indoor unit is located indoors and absorbs the indoor heat through the evaporation of the refrigerant to achieve indoor cooling. The compressor is responsible for compressing the low-pressure and low-temperature refrigerant gas to increase its temperature and pressure.

[0003] During the refrigeration process of the direct expansion air conditioner unit, since the refrigerant directly exchanges heat with the air, the temperature of the fin surface will decrease, resulting in the moisture in the air condensing into frost on the fin surface. The formation of the frost layer will gradually thicken, which will not only hinder the air flow, reduce the heat exchange efficiency, but also increase the energy consumption. Seriously, the frost layer may even block the evaporator, affecting the normal operation of the air conditioner. Therefore, regular defrosting operation is crucial for maintaining the efficient operation of the air conditioner unit.

[0004] In the prior art, typical defrosting methods mainly include three types: electric defrosting, water defrosting, and hot working medium defrosting. Electric defrosting uses an electric heating tube to heat the fins to melt the frost layer; water defrosting melts the frost layer by spraying water and using the heat of the water; while hot working medium defrosting uses the high-temperature refrigerant vapor discharged by the compressor, temporarily uses the evaporator as a condenser, and melts the frost layer with the heat released when the hot working medium condenses. The formation of the frost layer not only affects the operation efficiency of the air conditioner, but also increases the energy consumption. The thermal conductivity of frost is much lower than that of copper and aluminum, which are 0.116 - 0.139 w / m·k respectively, while the thermal conductivities of copper and aluminum are 397 w / m·k and 210 w / m·k respectively. The presence of the frost layer will narrow the flow channel and reduce the air volume, and ultimately may cause the evaporator to be completely blocked, seriously hindering the air flow. This will lead to the deterioration of the working conditions of the refrigeration device, difficult temperature reduction, reduced refrigeration capacity, and increased power consumption. Therefore, in a cold storage, the direct expansion air conditioner unit usually needs to be defrosted once after accumulating 5 - 8 hours of operation.

[0005] When the outdoor unit of an air conditioner unit enters the defrosting state is usually determined according to the values of temperature sensors arranged on the condenser fins or pressure sensors on the pipeline. However, during winter operation, there may be situations where the defrosting frequency is too high or it does not enter defrosting for a long time. An overly high defrosting frequency will cause the indoor temperature to rise too slowly, reduce efficiency, and result in energy waste; while not entering defrosting for a long time will cause the outdoor unit condenser to be covered with frost, affect the heat exchange efficiency of the heat exchanger, lead to a decline in refrigeration capacity, waste energy and fail to achieve the cooling effect. Summary of the Invention

[0006] The technical problem to be solved by the present utility model is to provide a direct expansion air conditioner unit with an automatic defrosting function.

[0007] To achieve the above technical objectives, the present utility model adopts the following technical solutions:

[0008] A direct expansion air conditioner unit with an automatic defrosting function includes an outdoor unit, an indoor unit and a compressor. The outdoor unit includes a casing;

[0009] The casing is provided with multiple groups of infrared opposed probe groups;

[0010] Each group of the infrared opposed probe groups includes a transmitter and a receiver; the positions of the transmitter and the receiver correspond one by one and are located on the windward surface of the casing.

[0011] Preferably, the perpendicular distances from the transmitter and the receiver to the windward surface of the casing are equal and are both 1 mm to 3.5 mm.

[0012] Preferably, the perpendicular distances from the transmitter and the receiver to the windward surface of the casing are equal and are both 2 mm to 3 mm.

[0013] Preferably, the perpendicular distances from the transmitter and the receiver to the windward surface of the casing are equal and are both 2.5 mm to 3 mm.

[0014] Preferably, the transmitter is located at the intersection of the top surface and the windward surface of the casing; the receiver is located at the intersection of the bottom surface and the windward surface of the casing;

[0015] The positions of the transmitter and the receiver are designed such that in the absence of an obstruction, the infrared signal emitted by the transmitter can be received by the receiver.

[0016] Preferably, multiple groups of the infrared opposed probe groups are evenly arranged on the windward surface of the casing.

[0017] Preferably, a plurality of fins are arranged inside the casing; each of the fins faces the windward surface of the outdoor unit.

[0018] Preferably, the value of the vertical distance varies according to different seasons or installation regions.

[0019] Preferably, the direct expansion air conditioning unit further includes a plurality of infrared pair - emission probe groups, which are evenly arranged on the windward surface and two side surfaces of the casing.

[0020] Compared with the prior art, the direct expansion air conditioning unit provided by the present utility model uses multiple groups of infrared pair - emission probe groups to detect the thickness of the frost layer, effectively avoiding the problem of false triggering that may be caused by debris blocking a single probe group, and at the same time solving the problem of failure to trigger defrosting in time due to insufficient number of probe groups. When the thickness of the frost layer reaches the preset value, the air conditioning unit will automatically switch to the defrosting state. After the frost layer melts, through logical design, it is ensured that the air conditioning unit can automatically exit the defrosting state in a timely manner, avoiding energy waste and efficiency reduction caused by long - term defrosting. This intelligent defrosting control mechanism not only improves the operating efficiency of the air conditioning unit, but also reduces energy consumption, ensuring that the air conditioning unit can operate stably and efficiently in various environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the internal structure of the outdoor unit in the direct expansion air conditioning unit provided by the present utility model;

[0022] Figure 2 It is a schematic diagram of multiple groups of infrared pair - emission probe groups in the direct expansion air conditioning unit provided by the present utility model;

[0023] Figure 3 It is a schematic diagram of the structure of a typical direct expansion air conditioning unit in the prior art. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The technical content of the present utility model will be described in detail below with reference to the drawings and specific embodiments.

[0025] As Figure 1 shown, an embodiment of the present utility model discloses a direct expansion air conditioning unit with an automatic defrosting function, including an outdoor unit (condenser), an indoor unit (evaporator) and a compressor. The working medium (refrigerant) forms a loop between the liquid receiver and the evaporator through a voltage expansion valve and a filter for refrigeration.

[0026] The outdoor unit 10 includes a casing 100, and an outdoor unit liquid phase interface 101, an outdoor unit gas phase interface 102, a compressor 11, a four - way valve 12, a condenser 13, an outdoor unit expansion valve 14, and a gas - liquid separator 15 located inside the casing 100.

[0027] The inlet of the compressor 11 is connected to the outlet of the gas-liquid separator 15, and the outlet of the compressor 11 is connected to the four-way valve 12. The four ends of the four-way valve 12 are respectively connected to the outlet of the compressor 11, the outdoor unit gas-phase interface 102, the inlet of the gas-liquid separator 15, and the condenser 13. The other end of the condenser 13 is successively connected to the outdoor unit expansion valve 14 and the outdoor unit liquid-phase interface 101. The inlet of the gas-liquid separator 15 is connected to the four-way valve 12, and the outlet is connected to the inlet of the compressor 11. Preferably, the outdoor unit expansion valve 14 is an electronic expansion valve.

[0028] As Figure 2 shown, inside the housing 100 of the outdoor unit 10, a plurality of heat dissipation fins 131 are provided around the condenser 13. The position of the fins 131 faces the windward surface 100A of the outdoor unit 10. Since the outdoor unit is usually a rectangular column, including a top surface, a bottom surface, a windward surface 100A facing the outdoor direction, a leeward surface (not shown) facing the indoor direction, and two side surfaces. The windward surface 100A and the leeward surface are both located between the top surface and the bottom surface. The top surface, the bottom surface, the windward surface 100A, the leeward surface and the two side surfaces together enclose a rectangular column as the housing 100.

[0029] In the direction perpendicular to the windward surface 100A (in other words, along the horizontal direction and towards the outdoor direction), a plurality of pairs of infrared opposed probe groups 2 are evenly arranged at a distance L. Among them, L is 1 mm to 3.5 mm, preferably 2 to 3 mm, and more preferably 2.5 to 3 mm. The value range of the distance L is selected according to the actual working conditions. Depending on the season or the installation area, the value of L is different. If the value of L is too large, the frost layer will be too thick, reducing the heating efficiency; if the value of L is too small, it will cause frequent defrosting, which will also reduce the heating efficiency. For example, when using air conditioners in winter in the northern and southern regions, since it is dry in the north and humid in the south, the value of L in the northern region is greater than that in the southern region. It should be noted that the value of the distance L from the transmitter 21 and the receiver 22 to the windward surface is obtained through a large amount of actual use data.

[0030] Each infrared opposed probe group 2 includes a transmitter 21 and a receiver 22. The transmitter 21 and the receiver 22 are installed in pairs on the housing 100 of the outdoor unit. The positions of the transmitter 21 and the receiver 22 correspond one by one and face each other, so that the infrared rays emitted by the transmitter 21 can be received by the receiver 22. Specifically, the transmitter 21 is close to the position where the top surface intersects the windward surface, and the receiver 22 is close to the position where the bottom surface intersects the windward surface. The distance from the transmitter 21 and the receiver 22 to the windward surface is L, so the distance from the infrared rays between the two to the windward surface 100A is also L. Since L is 1 mm to 3 mm, the infrared rays will be blocked by debris (such as leaves, plastic bags, etc.) higher than 3 mm on the windward surface.

[0031] The direct expansion air conditioner unit provided by the embodiment of the present utility model includes at least 3 infrared pair emission probe groups 2, which are evenly arranged on the windward surface. More preferably, it includes 9 infrared pair emission probe groups 2, which are evenly arranged on the windward surface and two side surfaces (that is, the three surfaces of the casing except the leeward surface, the top surface and the bottom surface). If a certain surface is blocked, or the frost layer on a certain surface is too thick but the frost layers on other surfaces are not thick, by arranging the infrared pair emission probe groups on the three surfaces, this kind of false triggering (automatically switching to the defrosting state when defrosting is not supposed to occur) can be avoided in this case.

[0032] Therefore, under normal working conditions, when the frost formation height is less than 3 mm, the receiver 22 can receive the signal of the transmitter 21, and the control board converts the received infrared signal into an electrical signal and determines it as normal (no defrosting is required). In other words, the control board can determine whether to enter the defrosting state according to the signal of the infrared sensor.

[0033] In an embodiment of the present utility model, the condition for entering the defrosting state is: when the received signals of multiple infrared pair emission probe groups 2 are interrupted (that is, the receiver 22 cannot receive the signal of the transmitter 21), enter the defrosting state immediately. The signals of multiple infrared pair emission probe groups 2 are interrupted, which indicates that the frost thickness on the windward surface 100A of the outdoor unit of the air conditioner unit has exceeded L at most monitoring positions and reaches the requirement for defrosting. At the same time, using the interruption of the signals of multiple infrared pair emission probe groups 2 as the judgment condition also avoids the false triggering of entering the defrosting state caused by one or two sensors being blocked by foreign objects.

[0034] In an embodiment of the present utility model, exiting the defrosting state includes one of the following conditions: Condition 1: After the air conditioner unit enters the defrosting state, when all signals can be received, exit the defrosting state after a 1-minute delay; Condition 2: Exit the defrosting state when some receivers have not received signals all the time but the longest defrosting time (8 minutes) is satisfied.

[0035] For Condition 1 of exiting defrosting, it does not exit immediately after all infrared signals are received. A 1-minute delay is required to reserve the time for the water droplets to drain from the fins after the frost melts, preventing the fins from icing and affecting the next defrosting. Condition 2 of exiting defrosting is to prevent the direct expansion air conditioner unit with an automatic defrosting function from being in the defrosting state for a long time due to foreign objects blocking multiple infrared pair emission probe groups 2, resulting in a reduction in the efficiency of the direct expansion machine and too slow an increase in the indoor temperature.

[0036] In summary, for the direct expansion air conditioning unit provided by the present utility model, when there is no frost blocking normally, the infrared receiver 22 can receive all the signals of the transmitter 21; after frosting occurs due to weather changes and the frost thickness exceeds the predetermined thickness (for example, 2.5 mm), the frost will block the signal of the transmitter 21, causing the receiver 22 to be unable to receive the signal. When multiple infrared probe receivers 22 all lose the signal, it indicates that the frost thickness has reached the requirement for defrosting, and then the defrosting state is entered. In this way, the timing of each defrosting can be accurately judged, avoiding frequent defrosting and the situation of not entering the defrosting state, enabling the air conditioning unit to be used for the heating condition to the greatest extent and avoiding waste of energy.

[0037] In addition, after entering the defrosting state, when all receivers can receive the signal, it still delays for 1 minute before exiting the defrosting state, or when some receivers have not received the signal all the time but meet the longest defrosting time (8 minutes), it exits the defrosting state. This can prevent the situation that one or two infrared probes are blocked by foreign objects and cannot exit the defrosting state in time.

[0038] Compared with the prior art, for the direct expansion air conditioning unit provided by the present utility model, by adopting multiple groups of infrared pair - emission probe groups to detect the frost layer thickness, it effectively avoids the problem that a single probe group may be mis - triggered due to being blocked by sundries, and at the same time solves the problem that the defrosting cannot be triggered in time due to insufficient number of probe groups. When the frost layer thickness reaches the preset value, the air conditioning unit will automatically switch to the defrosting state, and after the frost layer melts, through logical design, it is ensured that the air conditioning unit can automatically exit the defrosting state in a timely manner, avoiding energy waste and efficiency reduction caused by long - time defrosting. This intelligent defrosting control mechanism not only improves the operating efficiency of the air conditioning unit, but also reduces energy consumption, ensuring that the air conditioning unit can operate stably and efficiently in various environments.

[0039] The above has made a detailed description of the direct expansion air conditioning unit with an automatic defrosting function provided by the present utility model. For those of ordinary skill in the art, any obvious changes made to it without departing from the essence of the present utility model will constitute an infringement of the patent right of the present utility model and will bear corresponding legal responsibilities.

Claims

1. A direct expansion air conditioning unit with automatic defrosting function, comprising an outdoor unit, an indoor unit and a compressor, characterized in that: The outdoor unit comprises a casing; The housing is provided with a plurality of infrared radiation probe groups; Each of the infrared probe groups includes a transmitter and a receiver; the transmitter and the receiver are in one-to-one correspondence and are located on the windward side of the casing.

2. The direct expansion air conditioning unit with automatic defrosting function as claimed in claim 1, characterized in that: The vertical distances from the transmitter and the receiver to the wind-receiving surface of the casing are equal, and are both 1 mm to 3.5 mm.

3. The direct expansion air conditioning unit with automatic defrosting function as claimed in claim 2, characterized in that: The vertical distances from the transmitter and the receiver to the wind-receiving surface of the casing are equal, and are both 2 mm to 3 mm.

4. The direct expansion air conditioning unit with automatic defrosting function as claimed in claim 3, characterized in that: The vertical distances from the transmitter and the receiver to the wind-receiving surface of the casing are equal, and are both 2.5 mm to 3 mm.

5. The direct expansion air conditioning unit with automatic defrosting function according to any one of claims 1 to 4, characterized in that: The transmitter is located at the position where the top surface of the housing intersects with the wind receiving surface; The receiver is located at the intersection of the bottom surface of the housing and the wind receiving surface; The positions of the transmitter and the receiver are designed such that, in the absence of any obstruction, the infrared signal emitted by the transmitter can be received by the receiver.

6. The direct expansion air conditioning unit with automatic defrosting function as claimed in claim 5, characterized in that: A plurality of infrared radiation probe groups are evenly arranged on the wind-receiving surface of the casing.

7. The direct expansion air conditioning unit with automatic defrosting function as claimed in claim 6, characterized in that: A plurality of fins are arranged in the casing, and each of the fins faces the wind receiving surface of the outdoor unit.

8. The direct expansion air conditioning unit with automatic defrosting function as claimed in claim 7, characterized in that: The value of the vertical distance of the wind-receiving surface of the casing varies according to different seasons or installation areas.

9. The direct expansion air conditioning unit with automatic defrosting function as claimed in claim 7, characterized in that It also includes a plurality of infrared radiation probe groups, which are evenly arranged on the wind-receiving surface and two side surfaces of the casing.

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