Air conditioning unit and control method thereof

Abstract

The application discloses an air conditioning unit and a control method thereof, wherein the air conditioning unit comprises: a compressor, an oil separator, a condenser and an evaporator connected in sequence, the oil separator is connected with an oil return port of the compressor through a lubricating oil outlet; the air conditioning unit further comprises: an oil cooler, one end of which is connected with a refrigerant outlet of the condenser, the other end of which is connected with a refrigerant inlet of the condenser, the oil cooler is arranged in the oil separator, and is used for cooling lubricating oil in the oil separator by using refrigerant of the condensing outlet of the condenser; and a heat recovery device, one end of which is connected with heat recovery inlet water, the other end of which is connected with heat recovery outlet water, the heat recovery device is arranged in the oil separator, and is used for absorbing heat in the oil separator to heat heat recovery water. The application solves the problems of the existing technology, such as the increasing pressure difference of oil supply pipeline and the low heat recovery efficiency caused by the split design of the oil separator, the oil cooler and the heat recovery device, improves the oil return and the operation reliability of the unit, saves heat energy, and improves the heat exchange efficiency.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more specifically, to an air conditioning unit and its control method. Background Technology

[0002] Oil-injected screw chillers for refrigeration and freezing operate under conditions of low evaporation temperature and high condensation temperature, resulting in high exhaust temperature and high lubricating oil temperature, requiring oil coolers for cooling. Simultaneously, refrigeration and freezing units require heat recovery water during water defrosting, necessitating heat recovery units. Therefore, oil-injected screw chillers for refrigeration and freezing with heat recovery requirements typically consist of an oil separator, oil cooler, and heat recovery unit. The separate design of these components, connected by pipelines, not only increases unit cost but also presents several problems. For example, the separate oil cooler and oil separator are connected via an external oil return pipeline, increasing oil circuit resistance loss, reducing the pressure differential of the oil supply pipeline, and hindering oil return. Furthermore, the heat recovery unit's temperature is higher than the ambient temperature, resulting in heat exchange with the external environment, leading to reduced recovered heat and lower recovery efficiency, which is detrimental to energy conservation.

[0003] There is currently no effective solution to the problems of increased pressure differential in the oil supply pipeline and low heat recovery efficiency caused by the separate design of oil separator, oil cooler and heat recovery unit in related technologies. Summary of the Invention

[0004] This invention provides an air conditioning unit and its control method to at least solve the problems of increased pressure difference in the oil supply pipeline and low heat recovery efficiency in the separate design of oil separator, oil cooler and heat recovery unit in the prior art.

[0005] To solve the above-mentioned technical problems, according to one aspect of the present invention, an air conditioning unit is provided, comprising: 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 further comprises: 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 disposed within the oil separator for cooling the lubricating oil within the oil separator using the refrigerant from the condenser's condensation outlet; and a heat recovery unit, one end of which is connected to a heat recovery inlet water and the other end of which is connected to a heat recovery outlet water, the heat recovery unit being disposed within the oil separator for absorbing heat from the oil separator to heat the heat recovery water.

[0006] Further, the oil cooler includes: an oil cooling heat exchange coil disposed at the bottom of the oil separator and immersed in the lubricating oil within 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; and an oil cooling control valve located on the refrigerant inlet pipe of the oil cooling heat exchange coil for controlling the entry of refrigerant into the oil cooling heat exchange coil; wherein, the oil cooling control valve is an electronic expansion valve.

[0007] Furthermore, the heat recovery unit includes: a heat recovery heat exchange coil, which is disposed at the bottom of the oil separator and immersed in the lubricating oil in the oil separator; the heat recovery heat exchange coil includes a heat recovery inlet pipe and a heat recovery outlet pipe; and a heat recovery control valve, located on the inlet pipe of the heat recovery heat exchange coil, for controlling the entry of heat recovery water into the heat recovery heat exchange coil.

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

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

[0010] Furthermore, controlling the operation of the heat recovery unit based on the heat recovery outlet water temperature includes: acquiring a preset heat recovery water temperature, wherein the preset heat recovery water temperature includes at least a preset upper limit value and a preset lower limit value; controlling the heat recovery control valve to open when the heat recovery outlet water temperature is greater than or equal to the preset upper limit value; controlling the heat recovery control valve to close when the heat recovery outlet water temperature is less than or equal to the preset lower limit value; and controlling the heat recovery control valve to remain in its current state when the heat recovery outlet water temperature is greater than the preset lower limit value and less than the preset upper limit value.

[0011] Further, controlling the operation of the oil cooler based on the return oil temperature includes: acquiring a preset return oil temperature, wherein the preset return oil temperature is at least a preset upper limit value and a preset lower limit value; when the return oil temperature is greater than or equal to the preset upper limit value, controlling the oil cooling control valve to open; when the return oil temperature is less than or equal to the preset lower limit value, controlling the oil cooling control valve to close; and when the return oil temperature is greater than the preset lower limit value and less than the preset upper limit value, controlling the oil cooling control valve to remain in its current state.

[0012] Furthermore, after the control oil cooling control valve is opened, the method further includes: acquiring a preset target return oil temperature and the rate of change of the return oil temperature; determining whether it is necessary to adjust the opening degree of the oil cooling control valve based on the preset target return oil temperature and the rate of change of the return oil temperature; when it is necessary to adjust the opening degree of the oil cooling control valve, calculating the opening degree adjustment value of the oil cooling control valve, and adjusting the opening degree of the oil cooling control valve according to the opening degree adjustment value; when it is not necessary to adjust the opening degree of the oil cooling control valve, keeping the current opening degree of the oil cooling control valve unchanged.

[0013] Further, determining whether to adjust the opening of the oil cooling control valve based on 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 based on the difference A between the preset target return oil temperature and the return oil temperature and the rate of change of the return oil temperature B, where C = A * return oil temperature deviation coefficient a + B * return oil temperature change coefficient b; increasing the opening of the oil cooling control valve when the return oil temperature adjustment index C is greater than a first 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 a second preset value; and maintaining the current opening of the oil cooling control valve unchanged 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; 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 the present invention, a storage medium containing computer-executable instructions is provided, which, when executed by a computer processor, are used to perform the air conditioning unit control method as described above.

[0016] This invention provides an air conditioning unit with heat recovery functionality. This unit integrates the oil cooler and heat recovery unit within the oil separator, achieving an integrated design that reduces resistance losses in the connecting pipelines between the oil separator and oil cooler, minimizes pressure differential in the oil supply pipeline, facilitates oil return, and improves the reliability of oil return and unit operation. Simultaneously, it utilizes recovered heat water to cool the lubricating oil, saving thermal energy and avoiding heat loss from heat exchange between the independent heat recovery unit and the surrounding environment, thus improving heat exchange efficiency. This effectively solves the problems of increased pressure differential in the oil supply pipeline and lower heat recovery efficiency inherent in separate designs of the oil separator, oil cooler, and heat recovery unit. Furthermore, the integrated design of the oil separator, oil cooler, and heat recovery unit reduces the floor space required for the air conditioning unit, lowering its cost. Attached Figure Description

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

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

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

[0021] Explanation of reference numerals in the attached figures:

[0022] 1. Compressor; 2. Oil separator; 3. Heat recovery unit; 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 Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0024] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0025] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have 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] Depending on the context, the words “if” or “suppose” as used here can be interpreted as “when” or “in response to determination” or “in response to detection.” Similarly, depending on the context, the phrases “if determination” or “if detection (of the stated condition or event)” can be interpreted as “when determination” or “in response to determination” or “when detection (of the stated condition or event)” or “in response to detection (of the stated condition or event).”

[0028] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0029] The optional embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] Example 1

[0031] In the existing technology, oil-injected screw chiller units for refrigeration and cold storage with heat recovery requirements are usually composed of an oil separator, an oil cooler, and a heat recovery unit. The oil separator, oil cooler, and heat recovery unit are designed separately and connected by pipelines.

[0032] Specifically Figure 1This diagram illustrates one possible structural design of the air conditioning unit, such as... Figure 1 As shown, the air conditioning unit includes, in sequence, a compressor 1, an oil separator 2, a heat recovery unit 3, a condenser 4, and an oil cooler 5. High-temperature, high-pressure refrigerant vapor undergoes oil-gas separation in the oil separator 2. The separated refrigerant vapor first enters the heat recovery unit 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 supplies the evaporator, and the other path enters the oil cooler 5 to exchange heat with the lubricating oil. The heated refrigerant vapor then enters the condenser 4 for cooling. The lubricating oil separated by the oil separator 2 exchanges heat with the refrigerant at the evaporator outlet in the oil cooler 5. The cooled lubricating oil is then sprayed into the compressor 1 to provide cooling, noise reduction, and lubrication.

[0033] In the air conditioning unit with the split design of oil separator 2, oil cooler 5, and heat recovery unit 3, when the temperature of heat recovery unit 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 oil separator 2 through an external oil pipeline, which increases oil circuit resistance loss and is not conducive to oil return.

[0034] Based on the problems of increased pressure differential in the oil supply pipeline and low regeneration efficiency caused by the separate design of the oil separator, oil cooler, and heat recovery unit, the preferred embodiment of the present invention provides an air conditioning unit, specifically... Figure 2 This diagram illustrates one possible structural design of the unit, such as... Figure 2 As shown, the unit includes:

[0035] The compressor 1, oil separator 2, condenser 4 and 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] Oil cooler 5 is connected at one end to the refrigerant outlet of condenser 4 and at the other end to the refrigerant inlet of condenser 4. Oil cooler 5 is installed inside oil separator 2 and is used to cool the lubricating oil in oil separator 2 using the refrigerant from the condenser outlet of condenser 4.

[0037] The heat recovery unit 3 is connected at one end to the heat recovery inlet water 8 and at the other end to the heat recovery outlet water 9. The heat recovery unit 3 is installed inside the oil separator 2 and is used to absorb the heat in the oil separator 2 to heat the heat recovery water.

[0038] Refrigerant vapor from the evaporator is compressed by compressor 1 and then passes through oil separator 2 for oil-gas separation. The separated refrigerant vapor enters condenser 4 for condensation. The condensed high-temperature refrigerant liquid is divided into two paths: one path supplies the evaporator, and the other path enters oil cooler 5 to exchange heat with lubricating oil. The refrigerant vapor after heat exchange then enters condenser 4 for cooling. The lubricating oil carried in the exhaust of compressor 1 is separated and cooled by integrated oil separator 2 and then sprayed into compressor 1 through the oil supply line, serving to cool, reduce noise, and lubricate.

[0039] In the above embodiments, an air conditioning unit with heat recovery function is provided. This air conditioning unit integrates the oil cooler and heat recovery unit within the oil separator, i.e., the oil separator, oil cooler, and heat recovery unit are integrated into one design. This reduces the resistance loss of the connecting pipeline between the oil separator and the oil cooler, reduces the pressure difference in the oil supply pipeline, facilitates oil return, and improves the reliability of oil return and unit operation. Simultaneously, heat recovery water is used to cool the lubricating oil, saving thermal energy and avoiding heat loss caused by heat exchange between the independent heat recovery unit and the surrounding environment, thus improving heat exchange efficiency. This effectively solves the problems of increased pressure difference in the oil supply pipeline and low heat recovery efficiency inherent in separate designs of the oil separator, oil cooler, and heat recovery unit. Furthermore, the integrated design of the oil separator, oil cooler, and heat recovery unit can also reduce the floor space of the air conditioning unit and lower its cost.

[0040] Figure 3 A schematic diagram of one possible structure of the oil separator is shown, such as... Figure 3 As shown, the oil separator 2 includes an inlet 10 and an outlet 11. The gaseous refrigerant discharged from the compressor 1 enters through the inlet 10 and undergoes oil-gas separation in the oil separator 2. The separated refrigerant vapor enters the condenser 4. The oil cooler 5 includes: an oil-cooled heat exchange coil, such as... Figure 3 As shown, the oil-cooled heat exchange coil is located at the bottom of the oil separator 2 and is immersed in the lubricating oil within the oil separator 2. The oil-cooled 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. Additionally, an oil-cooling control valve 8 is included, located on the refrigerant inlet pipe 12 of the oil-cooled heat exchange coil, for controlling the entry of refrigerant into the oil-cooled heat exchange coil. The oil-cooling control valve 8 is an electronic expansion valve. By immersing the oil-cooled heat exchange coil in the lubricating oil within the oil separator 2, sufficient heat exchange is achieved between the oil-cooled heat exchange coil and the lubricating oil in the oil separator 2, improving heat exchange efficiency. Simultaneously, the heat exchange is controlled by the oil-cooling control valve 8. Furthermore, the oil-cooling control valve 8 can be an electronic expansion valve, thereby precisely regulating the oil supply temperature of the lubricating oil.

[0041] like Figure 3As shown, the heat recovery unit 3 includes: a heat recovery heat exchange coil, which is located at the bottom of the oil separator 2 and immersed in the lubricating oil within the oil separator 2; the heat recovery heat exchange coil includes a heat recovery inlet pipe (connected to the heat recovery water inlet) and a heat recovery outlet pipe (connected to the heat recovery water outlet); and a heat recovery control valve 7, located on the inlet pipe of the heat recovery heat exchange coil, used to control the entry of heat recovery water into the heat recovery heat exchange coil. By immersing the heat recovery heat exchange coil in the lubricating oil within the oil separator 2, sufficient heat exchange is achieved between the heat recovery heat exchange coil and the lubricating oil in the oil separator 2, improving heat exchange efficiency. Simultaneously, the heat exchange is controlled by the heat recovery control valve 7, regulating the temperature of the heat recovery water.

[0042] like Figure 2 As shown, this air conditioning unit also includes: an oil temperature sensor, located on the oil return line of compressor 1, used to detect the oil return temperature of compressor 1, so as to control the operation of oil cooler 5 according to the oil return temperature; and a heat recovery water outlet sensor, located on the heat recovery water outlet line, used to detect the heat recovery water outlet temperature, so as to control the operation of heat recovery unit 3 according to the heat recovery water outlet temperature. By detecting the oil return temperature and heat recovery water outlet temperature of compressor 1, the operation of oil cooler 5 and heat recovery unit 3 is precisely adjusted, thereby improving the intelligence of oil temperature control and heat recovery control.

[0043] This invention integrates the oil separator, oil cooler, and heat recovery unit. Through control valve switching and control, it achieves heat recovery and oil cooling functions, avoiding heat loss caused by heat exchange between the independent heat recovery unit and the surrounding environment, thus saving thermal energy. Heat recovery water can be used to cool the lubricating oil (during water defrosting), saving thermal energy. It also reduces resistance loss in the connecting pipeline between the oil separator and oil cooler, reduces pressure differential in the oil supply pipeline, and improves the reliability of unit operation.

[0044] Example 2

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

[0046] S402: Detects the compressor's oil return temperature and heat recovery outlet water temperature;

[0047] S404: Control the operation of the heat recovery unit according to the heat recovery outlet water temperature to regulate the heat recovery outlet water temperature;

[0048] S406: Control the operation of the oil cooler according to the return oil temperature to regulate the return oil temperature.

[0049] In the above embodiments, an air conditioning unit with heat recovery function is provided. This air conditioning unit integrates the oil cooler and heat recovery unit within the oil separator, i.e., the oil separator, oil cooler, and heat recovery unit are integrated into one design. This reduces the resistance loss of the connecting pipeline between the oil separator and the oil cooler, reduces the pressure difference in the oil supply pipeline, facilitates oil return, and improves the reliability of oil return and unit operation. Simultaneously, heat recovery water is used to cool the lubricating oil, saving thermal energy and avoiding heat loss caused by heat exchange between the independent heat recovery unit and the surrounding environment, thus improving heat exchange efficiency. This effectively solves the problems of increased pressure difference in the oil supply pipeline and low heat recovery efficiency inherent in separate designs of the oil separator, oil cooler, and heat recovery unit. Furthermore, the integrated design of the oil separator, oil cooler, and heat recovery unit can also reduce the floor space of the air conditioning unit and lower its cost.

[0050] In a preferred embodiment of the present invention, controlling the operation of the heat recovery unit based on the heat recovery outlet water temperature includes: acquiring a preset heat recovery water temperature, wherein the preset heat recovery water temperature includes at least a preset upper limit value and a preset lower limit value; controlling the heat recovery control valve to open when the heat recovery outlet water temperature is greater than or equal to the preset upper limit value; controlling the heat recovery control valve to close when the heat recovery outlet water temperature is less than or equal to the preset lower limit value; and controlling the heat recovery control valve to remain in its current state when the heat recovery outlet water temperature is greater than the preset lower limit value and less than the preset upper limit value.

[0051] A heat recovery control valve is installed at the inlet of the heat recovery coil, and a heat recovery outlet water sensor is installed at the outlet. The heat recovery outlet water temperature is [T]. 热回收出水温度 The upper limit of the heat recovery outlet water temperature is [T]. 热回收水温上限 The lower limit is [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 The heat recovery control valve opens.

[0053] When [T] 热回收出水温度 】≤

【T 热回收水温下限 The heat recovery control valve is closed.

[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 The heat recovery control valve remains unchanged.

[0055] First, adjust the opening and closing of the heat recovery control valve according to the heat recovery outlet water temperature to ensure that the heat recovery outlet water temperature meets the water demand, while reducing the temperature inside the oil separator.

[0056] After the heat recovery water meets the requirements, the temperature inside the oil separator has already decreased, but it is uncertain to what extent it has decreased. Therefore, the oil cooling control valve is then adjusted. The oil cooling control valve is an electronic expansion valve. By adjusting the opening of this electronic expansion valve, the return oil temperature is adjusted to meet the requirements, and finally, the heat recovery water temperature and the return oil temperature both meet the requirements.

[0057] Specifically, controlling the operation of the oil cooler based on the return oil temperature includes: acquiring a preset return oil temperature, wherein the preset return oil temperature is at least a preset upper limit value and a preset lower limit value; controlling the oil cooling control valve to open when the return oil temperature is greater than or equal to the preset upper limit value; controlling the oil cooling control valve to close when the return oil temperature is less than or equal to the preset lower limit value; and controlling the oil cooling control valve to remain in its current state when the return oil temperature is greater than the preset lower limit value but less than the preset upper limit value.

[0058] The lubricating oil carried in the compressor exhaust is separated and cooled by an integrated oil separator before being sprayed back into the compressor through the oil supply line, serving to cool, reduce noise, and lubricate. An oil cooling control valve and an oil temperature sensor are installed on the oil supply line, with the oil supply temperature set at [T]. 油温 The upper limit of the oil supply temperature is [T]. 油温上限 The lower limit is [T]. 油温下限 】:

[0059] When [T] 油温 】≥

【T 油温上限 The oil supply control valve opens;

[0060] When [T] 油温 】≤

【T 油温下限 The oil supply control valve is closed.

[0061] When [T] 油温下限 】<

T 油温

[0062] In another preferred embodiment of the present invention, after the oil cooling control valve is opened, the method further includes: acquiring a preset target return oil temperature and the rate of change of the return oil temperature; determining whether it is necessary to adjust the opening of the oil cooling control valve based on the preset target return oil temperature and the rate of change of the return oil temperature; if 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; if 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 precisely adjusted by adjusting the opening of the electronic expansion valve to ensure that the return oil temperature meets the requirements.

[0063] Specifically, determining whether to adjust the opening of the oil cooling control valve based on 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 based on the difference A and the rate of change of the return oil temperature B, where the return oil temperature adjustment index C = (the difference between the preset target return oil temperature and the return oil temperature) * return oil temperature deviation coefficient a + (the rate of change of the return oil temperature B) * return oil temperature change coefficient b; increasing the opening of the oil cooling control valve when the return oil temperature adjustment index C is greater than a first 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 a second preset value; and maintaining the current 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 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 indicates the deviation of the return oil temperature. When the return oil temperature adjustment index C is greater than a certain value, it indicates a large deviation, thus requiring an increase in the opening of the oil cooling control valve. When the return oil temperature adjustment index C is less than a certain value, it indicates a large deviation and overshoot, thus requiring a decrease in 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, it indicates a small deviation, thus requiring the current opening of the oil cooling control valve to remain unchanged. For example: if (the difference between the preset target return oil temperature and the return oil temperature A * return oil temperature deviation coefficient a + the rate of change of return oil temperature B * return oil temperature change coefficient b) > 2, then the oil cooling control valve will increase the corresponding adjustment step Dc at the current opening; if 0 ≤ (the difference between the preset target return oil temperature and the return oil temperature A * return oil temperature deviation coefficient a + the rate of change of return oil temperature B * return oil temperature change coefficient b) ≤ 2, the oil cooling control valve will maintain the current opening; if (the difference between the preset target return oil temperature and the return oil temperature A * return oil temperature deviation coefficient a + the rate of change of return oil temperature B * 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 degree of the oil cooling control valve needs adjustment, the adjustment value of the oil cooling control valve opening is calculated, including: obtaining the minimum adjustment range of the oil cooling control valve, calculating the product of the return oil temperature adjustment index C and the minimum adjustment range, and using this product as the adjustment value of the oil cooling control valve opening. The return oil temperature is gradually adjusted using the product of the return oil temperature adjustment index C and the minimum adjustment range as the adjustment step, until the return oil temperature meets the requirements.

[0066] Example 3

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

[0068] In the above embodiments, an air conditioning unit with heat recovery function is provided. This air conditioning unit integrates the oil cooler and heat recovery unit within the oil separator, i.e., the oil separator, oil cooler, and heat recovery unit are integrated into one design. This reduces the resistance loss of the connecting pipeline between the oil separator and the oil cooler, reduces the pressure difference in the oil supply pipeline, facilitates oil return, and improves the reliability of oil return and unit operation. Simultaneously, heat recovery water is used to cool the lubricating oil, saving thermal energy and avoiding heat loss caused by heat exchange between the independent heat recovery unit and the surrounding environment, thus improving heat exchange efficiency. This effectively solves the problems of increased pressure difference in the oil supply pipeline and low heat recovery efficiency inherent in separate designs of the oil separator, oil cooler, and heat recovery unit. Furthermore, the integrated design of the oil separator, oil cooler, and heat recovery unit can also reduce the floor space of the air conditioning unit and lower its cost.

[0069] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0070] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer 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. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

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

[0073] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0074] If the integrated unit is implemented as 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. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

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

[0076] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the 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 are connected in sequence, with the oil separator connected to the oil return port of the compressor via a lubricating oil outlet; The air conditioning unit also includes: An oil cooler is provided, with one end connected to the refrigerant outlet of the condenser and the other end connected to the refrigerant inlet of the condenser. The oil cooler is located inside the oil separator and is used to cool the lubricating oil inside the oil separator using the refrigerant from the condenser outlet. The heat recovery unit is connected at one end to the heat recovery inlet water and at the other end to the heat recovery outlet water. The heat recovery unit is installed inside the oil separator and is used to absorb the 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 includes: An oil-cooled heat exchange coil is provided at the bottom of the oil separator and immersed in the lubricating oil inside the oil separator. The oil-cooled 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 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 unit includes: A heat recovery heat exchange coil is disposed at the bottom of the oil separator and immersed in the lubricating oil inside the oil separator. The heat recovery heat exchange coil includes a heat recovery inlet pipe and a heat recovery outlet pipe. A heat recovery control valve is located on the inlet pipe of the heat recovery heat exchange coil and is used to control the entry of heat recovery water into 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 return oil line of the compressor, is used to detect 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 outlet water sensor, located on the heat recovery outlet water pipe, is used to detect the heat recovery outlet water temperature so as to control the operation of the heat recovery unit based on the heat recovery outlet water temperature.

5. An air conditioning unit control method, applied to an air conditioning unit as described in any one of claims 1 to 4, characterized in that, The method includes: Detect the compressor's oil return temperature and heat recovery outlet water temperature; First, control the operation of the heat recovery unit according to the heat recovery outlet water temperature to adjust the heat recovery outlet water temperature; The operation of the oil cooler is then controlled according to the return oil temperature to regulate the return oil temperature.

6. The method according to claim 5, characterized in that, Controlling the operation of the heat recovery unit based on the heat recovery outlet water temperature includes: Obtain a preset heat recovery water temperature, wherein the preset heat recovery water temperature has at least a preset upper limit value and a preset lower limit value; When the heat recovery outlet water temperature is greater than or equal to the preset upper limit value of the heat recovery water temperature, the heat recovery control valve is opened. When the heat recovery outlet water temperature is less than or equal to the preset lower limit of heat recovery water temperature, the heat recovery control valve is controlled to close. When the heat recovery outlet water temperature is greater than the preset lower limit of heat recovery water temperature but less than the preset upper limit of heat recovery water temperature, the heat recovery control valve is controlled to maintain its current state.

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

8. The method according to claim 7, characterized in that, After the control oil cooling control valve is opened, the following is also included: Obtain the preset target return oil temperature and the rate of change of the return oil temperature; Determine whether the opening of the oil cooling control valve needs to be adjusted based on the preset target return oil temperature and the rate of change of the return oil temperature. When it is necessary to adjust the opening of the oil cooling control valve, calculate the opening adjustment value of the oil cooling control valve, and adjust 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, the current opening of the oil cooling control valve shall remain unchanged.

9. The method according to claim 8, characterized in that, Determining whether to adjust the opening of the oil cooling control valve based on the preset target return oil temperature and the rate of change of the return oil temperature includes: Calculate the difference A between the preset target return oil temperature and the return oil temperature; The return oil temperature regulation index C is calculated based on 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. Where C = A * return oil temperature deviation coefficient a + B * return oil temperature variation coefficient b; When the oil return temperature regulation index C is greater than the first preset value, the opening of the oil cooling control valve is increased. When the oil return temperature regulation index C is less than the second preset value, the opening of the oil cooling control valve is reduced. When the return oil temperature regulation 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 degree of the oil cooling control valve remains 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: Obtain the minimum adjustment amplitude of the oil cooling control valve, calculate the product of the return oil temperature adjustment index C and the minimum adjustment amplitude, and use it 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, when executed by a computer processor, are used to perform the air conditioning unit control method as described in any one of claims 5 to 10.

Images