Air conditioning unit and control method thereof

Abstract

The invention discloses an air conditioning unit and a control method thereof.The air conditioning unit comprises a compressor, an oil separator, a condenser and an evaporator which are sequentially connected, and the oil separator is connected with an oil return opening of the compressor through a lubricating oil outlet; the air conditioning unit further comprises an oil cooler, one end of the oil cooler is connected with a refrigerant outlet of the condenser, the other end of the oil cooler is connected with a refrigerant inlet of the condenser, and the oil cooler is arranged in the oil separator and used for cooling lubricating oil in the oil separator through a refrigerant of a condensation outlet of the condenser. One end of the heat recoverer is connected with the heat recovery water inlet, the other end of the heat recoverer is connected with the heat recovery water outlet, and the heat recoverer is arranged in the oil separator and used for absorbing heat in the oil separator to heat the heat recovery water. The problems that in the prior art, an oil separator, an oil cooler and a heat recoverer are designed in a split mode, the pressure difference of an oil supply pipeline is increased, and the heat recovery efficiency is low are solved, the oil return and unit operation reliability is improved, meanwhile, heat energy is saved, and the heat exchange efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to an air conditioning unit and a control method thereof. Background Art

[0002] Since the oil-injected screw unit for refrigeration and freezing operates under the condition of low evaporation temperature and high condensation temperature, the exhaust temperature is high and the oil temperature of the lubricating oil is high, which requires an oil cooler for cooling. At the same time, the refrigeration and freezing unit needs to provide heat recovery water under conditions such as water defrosting, which requires a heat recovery device. Therefore, the oil-injected screw unit for refrigeration and freezing with heat recovery requirements is usually composed of an oil separator, an oil cooler, and a heat recovery device. The oil separator, oil cooler, and heat recovery device are split-type designs and connected by pipelines, which not only causes high unit costs, but also has many problems. For example: the split oil cooler is connected to the oil separator through an external return oil pipeline, which increases the resistance loss of the oil circuit, reduces the pressure difference of the oil supply pipeline, and is not conducive to oil return. The temperature of the heat recovery device is higher than the ambient temperature, and heat exchange is performed with the external environment, resulting in a reduction in recovered heat and low heat recovery efficiency, which is not conducive to energy saving.

[0003] The split design of oil separators, oil coolers and heat recovery devices in related technologies has the problems of increased pressure difference in the oil supply pipeline and low heat recovery efficiency, and no effective solution has been proposed so far. Summary of the invention

[0004] The present invention provides an air conditioning unit and a control method thereof, so as to at least solve the problems of increased pressure difference in the oil supply pipeline and low heat recovery efficiency in the split design of the oil separator, oil cooler and heat recovery device in the prior art.

[0005] To solve the above technical problems, according to one aspect of an embodiment of the present invention, an air-conditioning unit is provided, comprising: a compressor, an oil separator, a condenser and an evaporator connected in sequence, the oil separator being connected to the oil return port of the compressor via a lubricating oil outlet; the air-conditioning unit further comprises: an oil cooler, one end of which is connected to the refrigerant outlet of the condenser, and the other end is connected to the refrigerant inlet of the condenser, the oil cooler being arranged in the oil separator, and being used for cooling the lubricating oil in the oil separator by using the refrigerant at the condensation outlet of the condenser; a heat recovery device, one end of which is connected to the heat recovery water inlet, and the other end is connected to the heat recovery water outlet, the heat recovery device being arranged in the oil separator, and being used for absorbing heat in the oil separator to heat the heat recovery water.

[0006] Furthermore, the oil cooler includes: an oil cooling heat exchange coil, the oil cooling heat exchange coil is arranged at the bottom of the oil separator and immersed in the lubricating oil in the oil separator, the oil cooling heat exchange coil includes a refrigerant inlet pipe and a refrigerant outlet pipe, the refrigerant inlet pipe is connected to the refrigerant outlet of the condenser, and the refrigerant outlet pipe is connected to the refrigerant inlet of the condenser; an oil cooling control valve, located on the refrigerant inlet pipe of the oil cooling heat exchange coil, for controlling the refrigerant to enter the oil cooling heat exchange coil; wherein the oil cooling control valve is an electronic expansion valve.

[0007] Furthermore, the heat recovery device includes: a heat recovery heat exchange coil, which is arranged at the bottom of the oil separator and immersed in the lubricating oil in the oil separator, and the heat recovery heat exchange coil includes a heat recovery water inlet pipe and a heat recovery water outlet pipe; a heat recovery control valve, which is located on the water inlet pipe of the heat recovery heat exchange coil and is used to control the heat recovery water to enter the heat recovery heat exchange coil.

[0008] Furthermore, it also includes: an oil temperature sensor, located on the oil return pipeline of the compressor, for detecting the return oil temperature of the compressor, so as to control the operation of the oil cooler according to the return oil temperature; a heat recovery water outlet sensor, located on the heat recovery water outlet pipe, for detecting the heat recovery water outlet temperature, so as to control the operation of the heat recovery device according to the heat recovery water outlet temperature.

[0009] According to another aspect of an embodiment of the present invention, a method for controlling an air-conditioning unit is provided, which is applied to an air-conditioning unit as described above, and the method includes: detecting the return oil temperature and the heat recovery water outlet temperature of the compressor; controlling the operation of a heat recovery device according to the heat recovery water outlet temperature to adjust the heat recovery water outlet temperature; and controlling the operation of an oil cooler according to the return oil temperature to adjust the return oil temperature.

[0010] Furthermore, the operation of the heat recovery device is controlled according to the heat recovery water outlet temperature, including: obtaining a preset heat recovery water temperature, wherein the preset heat recovery water temperature includes at least a preset heat recovery water temperature upper limit value and a preset heat recovery water temperature lower limit value; when the heat recovery water outlet temperature is greater than or equal to the preset heat recovery water temperature upper limit value, controlling the heat recovery control valve to open; when the heat recovery water outlet temperature is less than or equal to the preset heat recovery water temperature lower limit value, controlling the heat recovery control valve to close; when the heat recovery water outlet temperature is greater than the preset heat recovery water temperature lower limit value and less than the preset heat recovery water temperature upper limit value, controlling the heat recovery control valve to maintain the current state unchanged.

[0011] Furthermore, the operation of the oil cooler is controlled according to the return oil temperature, including: obtaining a preset return oil temperature, wherein the preset return oil temperature includes at least a preset return oil temperature upper limit value and a preset return oil temperature lower limit value; when the return oil temperature is greater than or equal to the preset return oil temperature upper limit value, controlling the oil cooling control valve to open; when the return oil temperature is less than or equal to the preset return oil temperature lower limit value, controlling the oil cooling control valve to close; when the return oil temperature is greater than the preset return oil temperature lower limit value and less than the preset return oil temperature upper limit value, controlling the oil cooling control valve to maintain the current state unchanged.

[0012] Furthermore, after the oil cooling control valve is opened, it also includes: obtaining a preset target oil return temperature and a rate of change of the oil return temperature; judging whether it is necessary to adjust the opening of the oil cooling control valve according to the preset target oil return temperature and the rate of change of the oil return temperature; when it is necessary to adjust the opening of the oil cooling control valve, calculating an opening adjustment value of the oil cooling control valve, and adjusting the opening of the oil cooling control valve according to the opening adjustment value; when it is not necessary to adjust the opening of the oil cooling control valve, keeping the current opening of the oil cooling control valve unchanged.

[0013] Further, judging whether it is necessary to adjust the opening of the oil cooling control valve according to the preset target return oil temperature and the rate of change of the return oil temperature includes: calculating the difference A between the preset target return oil temperature and the return oil temperature; calculating the return oil temperature adjustment index C according to the difference A between the preset target return oil temperature and the return oil temperature and the rate of change B of the return oil temperature, wherein C=A*return oil temperature deviation coefficient a+B*return oil temperature change coefficient b; when the return oil temperature adjustment index C is greater than a first preset value, increasing the opening of the oil cooling control valve; when the return oil temperature adjustment index C is less than a second preset value, decreasing the opening of the oil cooling control valve; when the return oil temperature adjustment index C is less than or equal to the first preset value and greater than or equal to the second preset value, maintaining the current opening of the oil cooling control valve unchanged; wherein the first preset value is greater than the second preset value, and the second preset value is less than or equal to zero.

[0014] Further, calculating the opening adjustment value of the oil cooling control valve includes: obtaining the minimum adjustment amplitude of the oil cooling control valve, and calculating the product of the return oil temperature adjustment index C and the minimum adjustment amplitude as the opening adjustment value of the oil cooling control valve.

[0015] According to another aspect of an embodiment of the present invention, there is provided a storage medium comprising computer executable instructions, wherein the computer executable instructions are used to execute the air conditioning unit control method as described above when executed by a computer processor.

[0016] In the present invention, an air conditioning unit with a heat recovery function is provided, in which an oil cooler and a heat recovery device are arranged in an oil separator, that is, the oil separator, the oil cooler, and the heat recovery device are integrated in design, so as to reduce the resistance loss of the connecting pipeline between the oil separator and the oil cooler, reduce the pressure difference of the oil supply pipeline, facilitate oil return, and improve the reliability of oil return and unit operation. At the same time, heat recovery water is used to cool the lubricating oil, save heat energy, and avoid the heat loss caused by the heat exchange between the independent heat recovery device and the surrounding environment, thereby improving the heat exchange efficiency, and effectively solving the problems of increased pressure difference of the oil supply pipeline and low heat recovery efficiency in the split design of the oil separator, the oil cooler, and the heat recovery device. In addition, the integrated design of the oil separator, the oil cooler, and the heat recovery device can also reduce the floor space occupied by the air conditioning unit and reduce the cost of the air conditioning unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of an optional structure of an air conditioning unit in the prior art according to an embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of an optional structure of an air conditioning unit according to an embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of an optional structure of an oil separator according to an embodiment of the present invention;

[0020] Figure 4 is an optional flow chart of the air conditioning unit control method according to an embodiment of the present invention.

[0021] Description of reference numerals:

[0022] 1. Compressor; 2. Oil separator; 3. Heat recovery device; 4. Condenser; 5. Oil cooler; 6. Oil cooling control valve; 7. Heat recovery control valve; 8. Heat recovery water inlet; 9. Heat recovery water outlet; 10. Air inlet; 11. Air outlet; 12. Refrigerant inlet pipe; 13. Refrigerant outlet pipe. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0025] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0026] It should be understood that although the terms first, second, third, etc. may be used to describe controllers in embodiments of the present invention, these controllers should not be limited to these terms. These terms are only used to distinguish controllers connected to different devices. For example, without departing from the scope of embodiments of the present invention, a first controller may also be referred to as a second controller, and similarly, a second controller may also be referred to as a first controller.

[0027] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0028] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0029] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0030] Example 1

[0031] In the prior art, an oil-injected screw unit for refrigeration and freezing with heat recovery requirements is usually composed of an oil separator, an oil cooler, and a heat recovery device. The oil separator, oil cooler, and heat recovery device are designed in a split type and are connected by pipelines.

[0032] Specifically, Figure 1An optional structural diagram of the air conditioning unit is shown, such as Figure 1 As shown, the air conditioning unit includes: a compressor 1, an oil separator 2, a heat recovery device 3, a condenser 4 and an oil cooler 5 which are connected in sequence. The high-temperature and high-pressure refrigerant vapor is subjected to an oil-gas separator through the oil separator 2. The separated refrigerant vapor first enters the heat recovery device 3 to exchange heat with the heat recovery cooling water, and then enters the condenser 4 for condensation. The condensed refrigerant liquid is divided into two paths: one path is supplied to the evaporator, and the other path enters the oil cooler 5 to exchange heat with the lubricating oil. The heated refrigerant vapor enters the condenser 4 for cooling. The lubricating oil separated by the oil separator 2 exchanges heat with the refrigerant at the outlet of the evaporator in the oil cooler 5, and the cooled lubricating oil is sprayed into the compressor 1 to play the role of cooling, noise reduction and lubrication.

[0033] In the air conditioning unit with the oil separator 2, oil cooler 5 and heat recovery device 3 split design, when the temperature of the heat recovery device 3 is higher than the ambient temperature, heat exchange with the outside will lead to a reduction in recovered heat, which is not conducive to energy saving. At the same time, the split oil cooler 5 is connected to the oil separator 2 through an external oil pipeline, which increases the oil circuit resistance loss and is not conducive to oil return.

[0034] Based on the above-mentioned oil separator, oil cooler, and heat recovery device split design, there are problems such as increased pressure difference in the oil supply pipeline and low heat recovery efficiency. In a preferred embodiment 1 of the present invention, an air conditioning unit is provided. Specifically, Figure 2 An optional structural diagram of the unit is shown, such as Figure 2 As shown, the unit includes:

[0035] The compressor 1, the oil separator 2, the condenser 4 and the evaporator are connected in sequence, wherein the oil separator 2 is connected to the oil return port of the compressor 1 through the lubricating oil outlet;

[0036] The oil cooler 5 has one end connected to the refrigerant outlet of the condenser 4 and the other end connected to the refrigerant inlet of the condenser 4. The oil cooler 5 is arranged in the oil separator 2 and is used to cool the lubricating oil in the oil separator 2 using the refrigerant at the condensation outlet of the condenser 4.

[0037] The heat recovery device 3 has one end connected to the heat recovery water inlet 8 and the other end connected to the heat recovery water outlet 9. The heat recovery device 3 is arranged in the oil separator 2 and is used to absorb the heat in the oil separator 2 to heat the heat recovery water.

[0038] The refrigerant vapor from the evaporator is compressed by the compressor 1 and then separated by the oil separator 2. The separated refrigerant vapor enters the condenser 4 for condensation. The condensed high-temperature refrigerant liquid is divided into two paths: one path is supplied to the evaporator, and the other path enters the oil cooler 5 for heat exchange with the lubricating oil. The refrigerant vapor after heat exchange enters the condenser 4 for cooling. The lubricating oil entrained by the exhaust gas of the compressor 1 is separated and cooled by the integrated oil separator 2, and then sprayed into the compressor 1 through the oil supply pipeline, which plays the role of cooling, noise reduction and lubrication.

[0039] In the above embodiment, an air conditioning unit with a heat recovery function is provided, in which the oil cooler and the heat recovery device are arranged in the oil separator, that is, the oil separator, the oil cooler, and the heat recovery device are integrated into a design, which reduces the resistance loss of the connecting pipeline between the oil separator and the oil cooler, reduces the pressure difference of the oil supply pipeline, is conducive to oil return, and improves the oil return and unit operation reliability. At the same time, heat recovery water is used to cool the lubricating oil, save heat energy, and avoid the heat loss caused by the heat exchange between the independent heat recovery device and the surrounding environment, thereby improving the heat exchange efficiency, and effectively solving the problems of increased pressure difference in the oil supply pipeline and low heat recovery efficiency in the split design of the oil separator, oil cooler, and heat recovery device. In addition, the integrated design of the oil separator, oil cooler, and heat recovery device can also reduce the floor space occupied by the air conditioning unit and reduce the cost of the air conditioning unit.

[0040] Figure 3 An optional structural diagram of an oil separator is shown, such as Figure 3 As shown, the oil separator 2 includes an air inlet 10 and an air outlet 11. The gaseous refrigerant discharged from the compressor 1 enters through the air inlet 10, undergoes oil-gas separation in the oil separator 2, and the separated refrigerant vapor enters the condenser 4. The oil cooler 5 includes: an oil cooling heat exchange coil, such as Figure 3 As shown, the oil cooling heat exchange coil is arranged at the bottom of the oil separator 2 and immersed in the lubricating oil in the oil separator 2. The oil cooling heat exchange coil includes a refrigerant inlet pipe 12 and a refrigerant outlet pipe 13. The refrigerant inlet pipe 12 is connected to the refrigerant outlet of the condenser 4, and the refrigerant outlet pipe 13 is connected to the refrigerant inlet of the condenser 4. In addition, it also includes an oil cooling control valve 8, which is located on the refrigerant inlet pipe 12 of the oil cooling heat exchange coil and is used to control the refrigerant to enter the oil cooling heat exchange coil. Among them, the oil cooling control valve 8 is an electronic expansion valve. The oil cooling heat exchange coil is immersed in the lubricating oil in the oil separator 2, so that the oil cooling heat exchange coil and the lubricating oil in the oil separator 2 can fully exchange heat, improve the heat exchange efficiency, and control the heat exchange through the oil cooling control valve 8. In addition, the oil cooling control valve 8 can use an electronic expansion valve to accurately adjust the oil supply temperature of the lubricating oil.

[0041] like Figure 3As shown, the heat recovery device 3 includes: a heat recovery heat exchange coil, which is arranged at the bottom of the oil separator 2 and immersed in the lubricating oil in the oil separator 2, and the heat recovery heat exchange coil includes a heat recovery water inlet pipe (connected to the heat recovery water inlet) and a heat recovery water outlet pipe (connected to the heat recovery water outlet); a heat recovery control valve 7, which is located on the water inlet pipe of the heat recovery heat exchange coil and is used to control the heat recovery water to enter the heat recovery heat exchange coil. By immersing the heat recovery heat exchange coil in the lubricating oil in the oil separator 2, the heat recovery heat exchange coil and the lubricating oil in the oil separator 2 are fully exchanged with each other, thereby improving the heat exchange efficiency. At the same time, the heat exchange is controlled by the heat recovery control valve 7 to adjust the temperature of the heat recovery water.

[0042] like Figure 2 As shown, the air conditioning unit further includes: an oil temperature sensor, located on the oil return pipeline of the compressor 1, for detecting the oil return temperature of the compressor 1, so as to control the operation of the oil cooler 5 according to the oil return temperature; a heat recovery water outlet sensor, located on the heat recovery water outlet pipe, for detecting the heat recovery water outlet temperature, so as to control the operation of the heat recovery device 3 according to the heat recovery water outlet temperature. By detecting the oil return temperature and the heat recovery water outlet temperature of the compressor 1, the operation of the oil cooler 5 and the heat recovery device 3 can be accurately adjusted, thereby improving the intelligence of the oil temperature control and the heat recovery control.

[0043] The present invention integrates the oil separator, oil cooler and heat recovery device, realizes the heat recovery and oil cooling functions through the switching and control of the control valve, avoids the heat loss caused by the heat exchange between the independent heat recovery device and the surrounding environment, and saves heat energy. The heat recovery water can be used to cool the lubricating oil (when defrosting with water), saving heat energy. The resistance loss of the connecting pipeline between the oil separator and the oil cooler is reduced, the pressure difference of the oil supply pipeline is reduced, and the operation reliability of the unit is improved.

[0044] Example 2

[0045] In a preferred embodiment 2 of the present invention, a method for controlling an air conditioning unit is provided, which is applied to the air conditioning unit in the above embodiment 1. Specifically, Figure 4 An optional flow chart of the method is shown as follows: Figure 4 As shown, the method includes the following steps S402-S406:

[0046] S402: Detecting the oil return temperature of the compressor and the heat recovery water outlet temperature;

[0047] S404: controlling the operation of the heat recovery device according to the heat recovery water outlet temperature to adjust the heat recovery water outlet temperature;

[0048] S406: Controlling the operation of the oil cooler according to the return oil temperature to adjust the return oil temperature.

[0049] In the above embodiment, an air conditioning unit with a heat recovery function is provided, in which the oil cooler and the heat recovery device are arranged in the oil separator, that is, the oil separator, the oil cooler, and the heat recovery device are integrated into a design, which reduces the resistance loss of the connecting pipeline between the oil separator and the oil cooler, reduces the pressure difference of the oil supply pipeline, is conducive to oil return, and improves the oil return and unit operation reliability. At the same time, heat recovery water is used to cool the lubricating oil, save heat energy, and avoid the heat loss caused by the heat exchange between the independent heat recovery device and the surrounding environment, thereby improving the heat exchange efficiency, and effectively solving the problems of increased pressure difference in the oil supply pipeline and low heat recovery efficiency in the split design of the oil separator, oil cooler, and heat recovery device. In addition, the integrated design of the oil separator, oil cooler, and heat recovery device can also reduce the floor space occupied by the air conditioning unit and reduce the cost of the air conditioning unit.

[0050] In a preferred embodiment of the present invention, the operation of the heat recovery device is controlled according to the heat recovery water outlet temperature, including: obtaining a preset heat recovery water temperature, wherein the preset heat recovery water temperature is at least a preset heat recovery water temperature upper limit value and a preset heat recovery water temperature lower limit value; when the heat recovery water outlet temperature is greater than or equal to the preset heat recovery water temperature upper limit value, controlling the heat recovery control valve to open; when the heat recovery water outlet temperature is less than or equal to the preset heat recovery water temperature lower limit value, controlling the heat recovery control valve to close; when the heat recovery water outlet temperature is greater than the preset heat recovery water temperature lower limit value and less than the preset heat recovery water temperature upper limit value, controlling the heat recovery control valve to maintain the current state unchanged.

[0051] The heat recovery coil inlet is equipped with a heat recovery control valve and the outlet is equipped with a heat recovery water outlet sensor. The heat recovery water outlet temperature is [T 热回收出水温度 】. The upper limit of heat recovery water outlet temperature is

T 热回收水温上限

T 热回收水温下限

[0052] When

T 热回收出水温度

T 热回收水温上限

[0053] When

T 热回收出水温度

T 热回收水温下限

[0054] When

T 热回收水温下限

T 热回收出水温度

T 热回收水温上限

[0055] First, adjust the switch of the heat recovery control valve according to the heat recovery water outlet temperature so that the heat recovery water outlet temperature meets the water demand and reduces the temperature inside the oil separator at the same time.

[0056] After the heat recovery water meets the demand, since the temperature in the oil separator has been reduced, but it is uncertain to what extent, the oil cooling control valve is adjusted afterwards. The oil cooling control valve adopts an electronic expansion valve. By adjusting the opening of the electronic expansion valve, the return oil temperature is adjusted so that the return oil temperature meets the demand, and finally the effect of both the heat recovery water outlet temperature and the return oil temperature meeting the demand is achieved.

[0057] Specifically, the operation of the oil cooler is controlled according to the return oil temperature, including: obtaining a preset return oil temperature, wherein the preset return oil temperature is at least a preset return oil temperature upper limit value and a preset return oil temperature lower limit value; when the return oil temperature is greater than or equal to the preset return oil temperature upper limit value, controlling the oil cooling control valve to open; when the return oil temperature is less than or equal to the preset return oil temperature lower limit value, controlling the oil cooling control valve to close; when the return oil temperature is greater than the preset return oil temperature lower limit value and less than the preset return oil temperature upper limit value, controlling the oil cooling control valve to maintain the current state unchanged.

[0058] The lubricating oil carried by the compressor exhaust is separated and cooled by the integrated oil separator and then sprayed into the compressor through the oil supply pipeline, which plays the role of cooling, noise reduction and lubrication. The oil cooling control valve and oil temperature sensor are installed on the oil supply pipeline. The oil supply temperature is [T 油温 】. The upper limit of oil supply temperature is

T 油温上限

T 油温下限

[0059] When

T 油温

T 油温上限

[0060] When

T 油温

T 油温下限

[0061] When

T 油温下限

T 油温

T 油温上限

[0062] In another preferred embodiment of the present invention, after controlling the oil cooling control valve to open, it also includes: obtaining the preset target oil return temperature and the rate of change of the oil return temperature; judging whether it is necessary to adjust the opening of the oil cooling control valve according to the preset target oil return temperature and the rate of change of the oil return temperature; when it is necessary to adjust the opening of the oil cooling control valve, calculating the opening adjustment value of the oil cooling control valve, and adjusting the opening of the oil cooling control valve according to the opening adjustment value; when it is not necessary to adjust the opening of the oil cooling control valve, keeping the current opening of the oil cooling control valve unchanged. The oil cooling control valve adopts an electronic expansion valve. After the oil supply control valve is opened, the return oil temperature can be accurately adjusted by adjusting the opening of the electronic expansion valve so that the return oil temperature meets the demand.

[0063] Specifically, judging whether the opening of the oil cooling control valve needs to be adjusted according to the preset target oil return temperature and the rate of change of the oil return temperature includes: calculating the difference A between the preset target oil return temperature and the oil return temperature; calculating the oil return temperature adjustment index C according to the difference A between the preset target oil return temperature and the oil return temperature and the rate of change B of the oil return temperature, wherein the oil return temperature adjustment index C=the difference A between the preset target oil return temperature and the oil return temperature*the oil return temperature deviation coefficient a+the rate of change B of the oil return temperature*the oil return temperature change coefficient b; when the oil return temperature adjustment index C is greater than the first preset value, increasing the opening of the oil cooling control valve; when the oil return temperature adjustment index C is less than the second preset value, decreasing the opening of the oil cooling control valve; when the oil return temperature adjustment index C is less than or equal to the first preset value and greater than or equal to the second preset value, keeping the current opening of the oil cooling control valve unchanged. wherein the first preset value is greater than the second preset value, and the second preset value is less than or equal to zero.

[0064] The return oil temperature adjustment index C can indicate the deviation of the return oil temperature. When the return oil temperature adjustment index C is greater than a certain value, it means that the deviation is large, so it is necessary to adjust the opening of the oil cooling control valve to increase. When the return oil temperature adjustment index C is less than a certain value, it means that the deviation is large and overshoot, so it is necessary to adjust the opening of the oil cooling control valve to decrease. When the return oil temperature adjustment index C is less than or equal to the first preset value and greater than or equal to the second preset value, it means that the deviation is small, so the current opening of the oil cooling control valve is kept unchanged. For example: (the difference between the preset target return oil temperature and the return oil temperature A*the return oil temperature deviation coefficient a+the rate of change of the return oil temperature B*the return oil temperature change coefficient b)>2, the oil cooling control valve will increase the corresponding adjustment step Dc at the current opening; 0≤(the difference between the preset target return oil temperature and the return oil temperature A*the return oil temperature deviation coefficient a+the rate of change of the return oil temperature B*the return oil temperature change coefficient b)≤2, the oil cooling control valve maintains the current opening; (the difference between the preset target return oil temperature and the return oil temperature A*the return oil temperature deviation coefficient a+the rate of change of the return oil temperature B*the return oil temperature change coefficient b)<0, the oil cooling control valve will decrease the corresponding adjustment step Dc at the current opening.

[0065] After determining that the opening of the oil cooling control valve needs to be adjusted, the opening adjustment value of the oil cooling control valve is calculated, including: obtaining the minimum adjustment amplitude of the oil cooling control valve, calculating the product of the return oil temperature adjustment index C and the minimum adjustment amplitude as the opening adjustment value of the oil cooling control valve. The return oil temperature is gradually adjusted by using the product of the return oil temperature adjustment index C and the minimum adjustment amplitude as the adjustment step until the return oil temperature meets the demand.

[0066] Example 3

[0067] Based on the air conditioning unit control method provided in the above-mentioned embodiment 2, a storage medium containing computer executable instructions is also provided in a preferred embodiment 3 of the present invention. When the computer executable instructions are executed by a computer processor, they are used to execute the air conditioning unit control method as described above.

[0068] In the above embodiment, an air conditioning unit with a heat recovery function is provided, in which the oil cooler and the heat recovery device are arranged in the oil separator, that is, the oil separator, the oil cooler, and the heat recovery device are integrated into a design, which reduces the resistance loss of the connecting pipeline between the oil separator and the oil cooler, reduces the pressure difference of the oil supply pipeline, is conducive to oil return, and improves the oil return and unit operation reliability. At the same time, heat recovery water is used to cool the lubricating oil, save heat energy, and avoid the heat loss caused by the heat exchange between the independent heat recovery device and the surrounding environment, thereby improving the heat exchange efficiency, and effectively solving the problems of increased pressure difference in the oil supply pipeline and low heat recovery efficiency in the split design of the oil separator, oil cooler, and heat recovery device. In addition, the integrated design of the oil separator, oil cooler, and heat recovery device can also reduce the floor space occupied by the air conditioning unit and reduce the cost of the air conditioning unit.

[0069] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0070] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0071] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0072] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0073] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0074] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0075] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not invented by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0076] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. An air conditioning unit, characterized in that: include: A compressor, an oil separator, a condenser and an evaporator connected in sequence, wherein the oil separator is connected to the oil return port of the compressor via a lubricating oil outlet; The air conditioning unit also includes: an oil cooler, one end of which is connected to the refrigerant outlet of the condenser, and the other end of which is connected to the refrigerant inlet of the condenser, the oil cooler being arranged in the oil separator and used for cooling the lubricating oil in the oil separator by using the refrigerant at the condensation outlet of the condenser; A heat recovery device, one end of which is connected to the heat recovery water inlet, and the other end of which is connected to the heat recovery water outlet. The heat recovery device is arranged in the oil separator and is used to absorb heat in the oil separator to heat the heat recovery water.

2. The air conditioning unit according to claim 1, characterized in that: The oil cooler comprises: An oil-cooled heat exchange coil, the oil-cooled heat exchange coil is arranged at the bottom of the oil separator and immersed in the lubricating oil in the oil separator, the oil-cooled heat exchange coil comprises a refrigerant inlet pipe and a refrigerant outlet pipe, the refrigerant inlet pipe is connected to the refrigerant outlet of the condenser, and the refrigerant outlet pipe is connected to the refrigerant inlet of the condenser; The oil cooling control valve is located on the refrigerant inlet pipe of the oil cooling heat exchange coil and is used to control the refrigerant entering the oil cooling heat exchange coil; wherein the oil cooling control valve is an electronic expansion valve.

3. The air conditioning unit according to claim 1, characterized in that: The heat recovery device comprises: A heat recovery heat exchange coil, the heat recovery heat exchange coil is arranged at the bottom of the oil separator and immersed in the lubricating oil in the oil separator, the heat recovery heat exchange coil comprises a heat recovery water inlet pipe and a heat recovery water outlet pipe; The heat recovery control valve is located on the water inlet pipe of the heat recovery heat exchange coil and is used to control the heat recovery water to enter the heat recovery heat exchange coil.

4. The air conditioning unit according to claim 3, characterized in that: Also includes: an oil temperature sensor, located on the oil return pipeline of the compressor, for detecting the oil return temperature of the compressor, so as to control the operation of the oil cooler according to the oil return temperature; The heat recovery water outlet sensor is located on the heat recovery water outlet pipe and is used to detect the heat recovery water outlet temperature so as to control the operation of the heat recovery device according to the heat recovery water outlet temperature.

5. A method for controlling an air conditioning unit, applied to the air conditioning unit according to any one of claims 1 to 4, characterized in that: The method comprises: Detect the compressor's oil return temperature and heat recovery water outlet temperature; Controlling the operation of the heat recovery device according to the heat recovery water outlet temperature to adjust the heat recovery water outlet temperature; The operation of the oil cooler is controlled according to the oil return temperature to adjust the oil return temperature.

6. The method according to claim 5, characterized in that Controlling the operation of the heat recovery device according to the heat recovery water outlet temperature includes: Obtaining a preset heat recovery water temperature, wherein the preset heat recovery water temperature includes at least a preset heat recovery water temperature upper limit value and a preset heat recovery water temperature lower limit value; When the heat recovery water outlet temperature is greater than or equal to the preset heat recovery water temperature upper limit, controlling the heat recovery control valve to open; When the heat recovery water outlet temperature is less than or equal to the preset heat recovery water temperature lower limit, controlling the heat recovery control valve to close; When the heat recovery outlet water temperature is greater than the preset heat recovery water temperature lower limit value and less than the preset heat recovery water temperature upper limit value, the heat recovery control valve is controlled to maintain the current state unchanged.

7. The method according to claim 5, characterized in that Controlling the operation of the oil cooler according to the oil return temperature includes: Obtaining a preset oil return temperature, wherein the preset oil return temperature includes at least a preset oil return temperature upper limit value and a preset oil return temperature lower limit value; When the oil return temperature is greater than or equal to the preset oil return temperature upper limit value, the oil cooling control valve is controlled to open; When the return oil temperature is less than or equal to the preset return oil temperature lower limit, controlling the oil cooling control valve to close; When the oil return temperature is greater than the preset oil return temperature lower limit value and less than the preset oil return temperature upper limit value, the oil cooling control valve is controlled to maintain a current state.

8. The method according to claim 7, characterized in that After the oil cooling control valve is opened, the method further comprises: Obtaining a preset target oil return temperature and a rate of change of the oil return temperature; determining whether the opening of the oil cooling control valve needs to be adjusted according to the preset target oil return temperature and the rate of change of the oil return temperature; When the opening of the oil cooling control valve needs to be adjusted, calculating the opening adjustment value of the oil cooling control valve, and adjusting the opening of the oil cooling control valve according to the opening adjustment value; When the opening of the oil cooling control valve does not need to be adjusted, the current opening of the oil cooling control valve is kept unchanged.

9. The method according to claim 8, characterized in that Judging whether it is necessary to adjust the opening of the oil cooling control valve according to the preset target oil return temperature and the rate of change of the oil return temperature includes: Calculating a difference A between the preset target oil return temperature and the oil return temperature; The oil return temperature adjustment index C is calculated according to the difference A between the preset target oil return temperature and the oil return temperature and the change rate B of the oil return temperature, Wherein, C = A*return oil temperature deviation coefficient a+B*return oil temperature variation coefficient b; When the oil return temperature adjustment index C is greater than a first preset value, increasing the opening of the oil cooling control valve; When the oil return temperature adjustment index C is less than a second preset value, reducing the opening of the oil cooling control valve; When the return oil temperature adjustment index C is less than or equal to the first preset value and greater than or equal to the second preset value, the current opening of the oil cooling control valve is kept unchanged; wherein the first preset value is greater than the second preset value, and the second preset value is less than or equal to zero.

10. The method according to claim 9, characterized in that Calculating the opening adjustment value of the oil cooling control valve includes: The minimum adjustment amplitude of the oil cooling control valve is obtained, and the product of the return oil temperature adjustment index C and the minimum adjustment amplitude is calculated as the opening adjustment value of the oil cooling control valve.

11. A storage medium containing computer executable instructions, characterized in that: The computer executable instructions are used to execute the air conditioning unit control method according to any one of claims 5 to 10 when executed by a computer processor.

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