A heat pump system

Abstract

This application belongs to the field of smart home appliance technology, specifically relating to a heat pump system, including: a controller, a compressor, a lubricating oil replenishment device, an evaporator, a condenser, and a four-way valve; the compressor, four-way valve, evaporator, and condenser are connected in sequence, and the lubricating oil replenishment device is connected to the oil sump of the compressor; the lubricating oil replenishment device is used to replenish lubricating oil to the compressor, and to draw a portion of the lubricating oil from the compressor into the lubricating oil replenishment device; the controller is used to respond to a start command, control the compressor to start running, and determine whether the heat pump system is in a cold start state. If the heat pump system is in a cold start state, the controller controls the lubricating oil replenishment device to replenish lubricating oil to the compressor, and after replenishing the compressor with lubricating oil, the controller controls the lubricating oil replenishment device to draw a portion of the lubricating oil from the compressor into the lubricating oil replenishment device; this structure realizes the immediate availability of the heat pump system.

Description

Technical Field

[0001] This application relates to the field of smart home appliance technology, and in particular to a heat pump system. Background Technology

[0002] As a highly efficient cooling and heating device, heat pump systems face a series of technical challenges when first powered on after being left unattended for extended periods in low-temperature environments. Especially during cold seasons, the significant drop in ambient temperature can cause the compressor to experience excessively low exhaust temperatures during initial startup, leading to poor oil and fluid return.

[0003] Currently, the mainstream practice in the industry for addressing the initial startup issue of air source heat pump systems after a prolonged power outage at low temperatures is to attach an oil heating belt to the bottom of the compressor. This method, through prolonged preheating with electricity, raises the internal temperature of the compressor, thereby reducing the viscosity of the lubricating oil and evaporating the refrigerant in the oil sump at the bottom of the compressor. This measure aims to prevent the refrigerant evaporation from carrying away the lubricating oil during startup, thus ensuring the lubrication of the compressor's compression components.

[0004] However, with existing oil-heated preheating methods, users must wait for the compressor to finish preheating before starting the system. Furthermore, because the preheating process is not user-controlled, users cannot schedule the start-up time according to their actual needs. Therefore, existing heat pump systems suffer from poor immediate availability. Summary of the Invention

[0005] This application provides a heat pump system to address the problem of poor real-time availability of existing heat pump systems.

[0006] In a first aspect, embodiments of this application provide a heat pump system, characterized in that it includes: a controller, a compressor, a lubricating oil replenishment device, an evaporator, a condenser, and a four-way valve; the compressor, the four-way valve, the evaporator, and the condenser are connected in sequence, and the lubricating oil replenishment device is connected to the oil sump of the compressor;

[0007] The lubricating oil replenishing device is used to replenish lubricating oil to the compressor, and to draw a portion of the lubricating oil in the compressor into the lubricating oil replenishing device;

[0008] The controller is used to respond to a start command, control the compressor to start running, and determine whether the heat pump system is in a cold start state. If the heat pump system is in a cold start state, the controller controls the lubricating oil replenishment device to replenish lubricating oil to the compressor, and after replenishing the lubricating oil to the compressor, the controller controls the lubricating oil replenishment device to draw a portion of the lubricating oil in the compressor into the lubricating oil replenishment device.

[0009] As an optional implementation, the lubricating oil replenishment device includes a pipeline, a first valve, a second valve, a third valve, a fourth valve, and an oil pump, wherein the first valve, the second valve, the third valve, the fourth valve, and the oil pump are all electrically connected to the controller;

[0010] The pipeline includes a main line, a first branch line, and a second branch line. The main line includes a first inlet and a first outlet. The pipeline between the first inlet and the first outlet is located within the cavity of the lubricating oil replenishment device. The first inlet and the first outlet extend outside the cavity and connect to the oil sump of the compressor. A first valve is located outside the first inlet, and a second valve is located outside the first outlet. The oil pump is located on the main line within the cavity. One end of the first branch line connects to the position between the oil pump and the first inlet on the main line, and the other end connects to the cavity. A third valve is located on the first branch line. One end of the first branch line connects to the position between the oil pump and the first outlet on the main line, and the other end connects to the cavity. A fourth valve is located on the second branch line.

[0011] The controller is used to control the first valve and the fourth valve to close, and to control the second valve, the third valve and the oil pump to open, so as to control the lubricating oil replenishment device to replenish lubricating oil to the compressor;

[0012] The controller is used to close the second valve and the third valve, and to open the first valve, the fourth valve and the oil pump to draw some of the lubricating oil from the compressor into the lubricating oil replenishment device.

[0013] As an optional implementation, the lubricating oil replenishing device includes a fifth valve, which is electrically connected to the controller. The pipeline includes a third branch, which is located outside the top opening of the lubricating oil replenishing device and connected to the gas separator of the compressor. The fifth valve is located on the third branch.

[0014] The controller is used to control the fifth valve, the first valve, the second valve and the oil pump to open after a portion of the lubricating oil in the compressor is drawn into the lubricating oil replenishment device, so as to recover the gaseous refrigerant in the lubricating oil replenishment device to the gas separator of the compressor.

[0015] As an optional implementation, an oil viscometer is installed in the cavity of the lubricating oil replenishment device, and the oil viscometer is electrically connected to the controller;

[0016] The controller is used to detect the viscosity of the lubricating oil in the lubricating oil replenishment device cavity through the oil viscometer, and when the lubricating oil viscosity is lower than a preset threshold, it controls the fifth valve, the first valve, the second valve and the oil pump to open.

[0017] As an optional implementation, the controller is configured to control the lubricating oil replenishment device to draw a portion of the lubricating oil from the compressor into the lubricating oil replenishment device after a first period of time following the start of the compressor, or when the exhaust temperature of the compressor is greater than or equal to a first temperature threshold.

[0018] As an optional implementation, a first liquid level detection device is provided in the cavity of the lubricating oil replenishment device, and the first liquid level detection device is electrically connected to the controller;

[0019] The controller is used to stop drawing lubricating oil from the compressor into the lubricating oil replenishment device when the liquid level in the lubricating oil replenishment device reaches the position of the first liquid level detection device.

[0020] As an optional implementation, the compressor is provided with a second liquid level detection device and a third liquid level detection device, the second liquid level detection device being positioned lower than the third liquid level detection device, and both the second and third liquid level detection devices being electrically connected to the controller.

[0021] The controller is used to control the lubricating oil replenishment device to replenish lubricating oil to the compressor when the oil level in the compressor's oil sump is lower than the position of the second level detection device, and to control the lubricating oil replenishment device to stop replenishing lubricating oil to the compressor when the oil level in the compressor's oil sump reaches the position of the third level detection device, and to control the lubricating oil replenishment device to draw a portion of the lubricating oil in the compressor into the lubricating oil replenishment device until the oil level in the compressor's oil sump returns to the position of the second level detection device.

[0022] As an optional implementation, the controller is used to determine that the heat pump system is in a cold start state when the shutdown duration of the heat pump system is greater than or equal to a second duration and the difference between the exhaust temperature of the compressor and the ambient temperature is less than or equal to a second temperature threshold.

[0023] The controller is used to determine that the heat pump system is in a cold start state when it is first started after being powered on.

[0024] As an optional implementation, the position of the first inlet is higher than the position of the first outlet.

[0025] As an optional implementation, this application provides a heat pump system, further comprising: an economizer, wherein the main circuit of the economizer is connected between the evaporator and the condenser, and the auxiliary circuit of the economizer is connected to the compressor.

[0026] This application provides a heat pump system comprising: a controller, a compressor, a lubricating oil replenishment device, an evaporator, a condenser, and a four-way valve; the compressor, the four-way valve, the evaporator, and the condenser are connected in sequence, and the lubricating oil replenishment device is connected to the oil sump of the compressor; the lubricating oil replenishment device is used to replenish lubricating oil to the compressor and to draw a portion of the lubricating oil from the compressor into the lubricating oil replenishment device; the controller is used to respond to a start command, control the compressor to start operation, and determine whether the heat pump system is in a cold start state. If the heat pump system is in a cold start state, the controller controls the lubricating oil replenishment device to replenish lubricating oil to the compressor, and after replenishing the compressor with lubricating oil, the controller controls the lubricating oil replenishment device to draw a portion of the lubricating oil from the compressor into the lubricating oil replenishment device; this structure enables the immediate availability of the heat pump system. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0028] Figure 1 The schematic diagram of the heat pump system provided in this application Figure 1 ;

[0029] Figure 2 A schematic diagram of the lubricating oil replenishment device in the heat pump system provided in this application;

[0030] Figure 3 The schematic diagram of the heat pump system provided in this application Figure 2 ;

[0031] Figure 4 The schematic diagram of the heat pump system provided in this application Figure 3 ;

[0032] Figure 5 The schematic diagram of the heat pump system provided in this application Figure 4 ;

[0033] Figure 6 The schematic diagram of the heat pump system provided in this application Figure 5 .

[0034] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments.

[0035] Reference numerals: 1. Controller; 2. Compressor; 3. Lubricating oil replenishment device; 4. Evaporator; 5. Condenser; 6. Four-way valve; 7. Piping; 8. First valve; 9. Second valve; 10. Third valve; 11. Fourth valve; 12. Oil pump; 13. Fifth valve; 14. Gas separator; 15. First liquid level detection device; 16. Second liquid level detection device; 17. Third liquid level detection device; 18. Economizer. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] First, those skilled in the art should understand that these embodiments are merely for explaining the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0038] Secondly, it should be noted that in the description of this invention, terms such as "inner" and "outer" indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0039] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0040] Heat pump systems, as highly efficient devices integrating cooling and heating functions, face numerous technical challenges when first powered on under extreme climatic conditions, especially after prolonged power outages in low-temperature environments. Particularly in winter, the significant drop in ambient temperature presents the challenge of low exhaust temperatures during the initial startup of the compressor. This often obstructs the oil and liquid return process, affecting the normal operation of the heat pump system. Proper circulation of the compressor's internal lubricating oil and effective lubrication of its components are particularly crucial under low-temperature startup conditions.

[0041] The commonly adopted measure is to install an oil heating strip at the bottom of the compressor. This strip, pre-heated by electricity, raises the internal temperature of the compressor, effectively reducing the viscosity of the lubricating oil and promoting the evaporation of refrigerant in the oil sump at the bottom of the compressor. The core purpose of this measure is to prevent the lubricating oil from being carried away by refrigerant evaporation during compressor startup, ensuring that critical internal components of the compressor receive adequate lubrication and protection.

[0042] However, with existing oil-heated preheating methods, users must wait for the compressor to finish preheating before starting the system. Furthermore, because the preheating process is not user-controlled, users cannot schedule the start-up time according to their actual needs. Therefore, existing heat pump systems suffer from poor immediate availability.

[0043] To address the aforementioned issues, this application provides a heat pump system integrating a controller, compressor, lubricating oil replenishment device, evaporator, condenser, and four-way valve. Through connection and control logic, it achieves efficient operation and intelligent maintenance. In the heat pump system, the compressor, four-way valve, evaporator, and condenser are interconnected sequentially to form a basic heat pump circulation path, while the lubricating oil replenishment device is directly connected to the compressor oil sump and is responsible for dynamically adjusting the amount of lubricating oil in the compressor. Upon receiving a start command, the controller not only starts the compressor but also intelligently determines whether the heat pump system is in a cold start state. Once confirmed, the controller instructs the lubricating oil replenishment device to replenish lubricating oil to the compressor to ensure smooth start-up. After replenishing the compressor, the controller instructs it to recover a portion of the lubricating oil to maintain the lubricating oil balance within the heat pump system. This structure ensures the immediate availability of equipment within the heat pump system.

[0044] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0045] This application provides a wired remote control, such as... Figure 1As shown, the heat pump system of this embodiment includes: a controller 1, a compressor 2, a lubricating oil replenishment device 3, an evaporator 4, a condenser 5, and a four-way valve 6; the compressor 2, the four-way valve 6, the evaporator 4, and the condenser 5 are connected in sequence, and the lubricating oil replenishment device 3 is connected to the oil sump of the compressor 2.

[0046] The lubricating oil replenishing device 3 is used to replenish lubricating oil to the compressor 2, and to draw a portion of the lubricating oil in the compressor 2 into the lubricating oil replenishing device 3;

[0047] Controller 1 is used to respond to the start command, control the compressor 2 to start running, and determine whether the heat pump system is in a cold start state. If the heat pump system is in a cold start state, it controls the lubricating oil replenishment device 3 to replenish lubricating oil to the compressor 2. After the lubricating oil is replenished to the compressor 2, it controls the lubricating oil replenishment device 3 to suck a portion of the lubricating oil in the compressor 2 into the lubricating oil replenishment device 3.

[0048] The heat pump system mainly consists of key components such as controller 1, compressor 2, lubricating oil replenishment device 3, evaporator 4, condenser 5, and four-way valve 6. These components are connected to form a highly efficient whole.

[0049] The compressor 2, four-way valve 6, evaporator 4, and condenser 5 are the core circulation components of the heat pump system. They are connected in sequence to form a closed refrigerant circulation loop. This loop is responsible for transferring heat from a low-temperature environment to a high-temperature environment, thus realizing the basic function of a heat pump.

[0050] The lubricating oil replenishment device 3 is connected to the oil sump of the compressor 2. During the operation of the heat pump system, the lubricating oil replenishment device 3 is responsible for replenishing the compressor 2 with an appropriate amount of lubricating oil to ensure the normal operation and high efficiency of the compressor 2.

[0051] Controller 1 is the "brain" of the heat pump system. It is responsible for responding to start-up commands and controlling the start-up and operation of compressor 2. Controller 1 can also intelligently detect whether the heat pump system is in a cold start state. In a cold start state, controller 1 will control the lubricating oil replenishment device 3 to replenish lubricating oil to compressor 2 to ensure that compressor 2 can start quickly even in low-temperature environments. After replenishing the oil, controller 1 will also control the lubricating oil replenishment device 3 again to recover some of the lubricating oil to maintain the stable operation of the heat pump system.

[0052] This application provides a heat pump system, comprising: a controller 1, a compressor 2, a lubricating oil replenishment device 3, an evaporator 4, a condenser 5, and a four-way valve 6; the compressor 2, the four-way valve 6, the evaporator 4, and the condenser 5 are connected in sequence, and the lubricating oil replenishment device 3 is connected to the oil sump of the compressor 2; the lubricating oil replenishment device 3 is used to replenish lubricating oil to the compressor 2, and to draw a portion of the lubricating oil from the compressor 2 into the lubricating oil replenishment device 3; the controller 1 is used to respond to a start command, control the compressor 2 to start operation, and determine whether the heat pump system is in a cold start state; if the heat pump system is in a cold start state, it controls the lubricating oil replenishment device 3 to replenish lubricating oil to the compressor 2, and after replenishing the compressor 2 with lubricating oil, it controls the lubricating oil replenishment device 3 to draw a portion of the lubricating oil from the compressor 2 into the lubricating oil replenishment device 3; this structure realizes the immediate availability of the heat pump system.

[0053] In one possible implementation, such as Figure 2 As shown, the lubricating oil replenishment device 3 includes a pipeline 7, a first valve 8, a second valve 9, a third valve 10, a fourth valve 11, and an oil pump 12. The first valve 8, the second valve 9, the third valve 10, the fourth valve 11, and the oil pump 12 are all electrically connected to the controller 1.

[0054] Pipeline 7 includes a main line, a first branch line, and a second branch line. The main line includes a first inlet and a first outlet. Pipeline 7 between the first inlet and the first outlet is located within the cavity of the lubricating oil replenishment device 3. The first inlet and the first outlet extend outside the cavity and connect to the oil sump of the compressor 2. A first valve 8 is located outside the first inlet, and a second valve 9 is located outside the first outlet. An oil pump 12 is located on the main line within the cavity. One end of the first branch line connects to the position between the oil pump 12 and the first inlet on the main line, and the other end connects to the cavity. A third valve 10 is located on the first branch line. One end of the first branch line connects to the position between the oil pump 12 and the first outlet on the main line, and the other end connects to the cavity. A fourth valve 11 is located on the second branch line.

[0055] The controller 1 is used to control the first valve 8 and the fourth valve 11 to close, and to control the second valve 9, the third valve 10 and the oil pump 12 to open, so as to control the lubricating oil replenishment device 3 to replenish lubricating oil to the compressor 2;

[0056] The controller 1 is used to control the second valve 9 and the third valve 10 to close, and to control the first valve 8, the fourth valve 11 and the oil pump 12 to open, so as to draw some of the lubricating oil in the compressor 2 into the lubricating oil replenishment device 3.

[0057] The lubricating oil replenishment device 3 integrates multiple components to ensure the effective management and distribution of lubricating oil. The core components of the lubricating oil replenishment device 3 include pipeline 7, first valve 8, second valve 9, third valve 10, fourth valve 11, and oil pump 12. All of these components are electrically connected to the controller 1, thereby achieving intelligent control.

[0058] In the design of pipeline 7, the lubricating oil replenishment device 3 adopts a layout of a main pipeline, a first branch pipeline, and a second branch pipeline. One end of the main pipeline (the first inlet) is connected to the oil sump of compressor 2, and the other end (the first outlet) is also connected to the oil sump of compressor 2, forming a complete lubricating oil circulation path. On the main pipeline, the oil pump 12 is installed in the cavity to provide the power for the flow of lubricating oil. The first valve 8 and the second valve 9 are respectively located outside the inlet and outlet of the main pipeline to control the entry and exit of lubricating oil.

[0059] Furthermore, the design of the first and second branches further enhances the flexibility of the lubricating oil replenishment device 3. The first branch connects the oil pump 12 of the main line to the first inlet, while the second branch connects the oil pump 12 to the first outlet. These two branches are equipped with a third valve 10 and a fourth valve 11, respectively, allowing the controller 1 to flexibly adjust the flow direction and flow rate of the lubricating oil according to actual needs.

[0060] In terms of control logic, controller 1 plays a crucial role. When lubricating oil needs to be added to compressor 2, controller 1 closes the first valve 8 and the fourth valve 11, while opening the second valve 9, the third valve 10, and the oil pump 12, thereby guiding the lubricating oil from the main line into compressor 2. Conversely, when some of the lubricating oil in compressor 2 needs to be drawn back to the lubricating oil replenishment device 3, controller 1 closes the second valve 9 and the third valve 10, while opening the first valve 8, the fourth valve 11, and the oil pump 12, achieving the return flow of lubricating oil.

[0061] In one possible implementation, such as Figure 3 As shown, the lubricating oil replenishing device 3 includes a fifth valve 13, which is electrically connected to the controller 1. The pipeline 7 includes a third branch, which is located outside the top opening of the lubricating oil replenishing device 3 and connected to the gas separator 14 of the compressor 2. The fifth valve 13 is located on the third branch.

[0062] The controller 1 is used to control the fifth valve 13, the first valve 8, the second valve 9 and the oil pump 12 to open after a portion of the lubricating oil in the compressor 2 is drawn into the lubricating oil replenishment device 3, so as to recover the gaseous refrigerant in the lubricating oil replenishment device 3 to the gas separator 14 of the compressor 2.

[0063] The lubricating oil replenishment device 3 has added a key component—the fifth valve 13, and a third branch has also been added to the pipeline 7.

[0064] The fifth valve 13 is electrically connected to the controller 1, meaning that its opening and closing can be intelligently controlled by the controller 1. This newly added third branch is located outside the top opening of the lubricating oil replenishment device 3 and is connected to the gas separator 14 of the compressor 2. This design allows the lubricating oil replenishment device 3 to process and recover the gaseous refrigerant while recovering the lubricating oil.

[0065] After controller 1 completes the process of drawing some lubricating oil from compressor 2 into lubricating oil replenishment device 3, controller 1 will further issue a command to simultaneously open the fifth valve 13, the first valve 8, the second valve 9, and the oil pump 12. This will trigger a lubricating oil recovery process: the gaseous refrigerant in lubricating oil replenishment device 3 will be smoothly recovered along the third branch to the gas separator 14 of compressor 2.

[0066] This new feature not only enhances the practicality of the lubricating oil replenishment device 3, but also helps improve the energy efficiency and stability of the entire heat pump system. Through intelligent control and ingenious design, the lubricating oil replenishment device 3 can effectively process and recover the gaseous refrigerant while recovering the lubricating oil.

[0067] In one possible implementation, an oil viscometer is installed in the cavity of the lubricating oil replenishment device 3, and the oil viscometer is electrically connected to the controller 1.

[0068] The controller 1 is used to detect the viscosity of the lubricating oil in the lubricating oil replenishment device 3 by means of an oil viscometer. When the viscosity of the lubricating oil is lower than a preset threshold, the controller controls the fifth valve 13, the first valve 8, the second valve 9 and the oil pump 12 to open.

[0069] In the design of the lubricating oil replenishment device 3, an oil viscometer was added to the cavity to further enhance its intelligence and automation level. The oil viscometer is electrically connected to the controller 1, enabling the controller 1 to obtain the viscosity information of the lubricating oil in the cavity in real time.

[0070] An oil viscometer is used to test the performance condition of lubricating oil. Viscosity is an important physical property of lubricating oil, directly affecting its flowability and lubrication effect. If the viscosity of the lubricating oil is too low, its lubrication performance may be greatly reduced, thereby increasing the risk of wear on components such as compressors.

[0071] Controller 1 can automatically detect and respond to changes in lubricating oil viscosity. When the oil viscometer detects that the viscosity of the lubricating oil in the chamber is lower than a preset threshold (e.g., 0.8 centipoise), controller 1 will take immediate action. It will control the fifth valve 13, the first valve 8, the second valve 9, and the oil pump 12 to open simultaneously, drawing some of the lubricating oil from the compressor 2 into the lubricating oil replenishment device 3 for necessary processing and adjustment. Simultaneously, because the lubricating oil viscosity is lower at this time, it is also more suitable for gaseous refrigerant recovery, thereby further improving the overall energy efficiency of the heat pump system.

[0072] In one alternative implementation, the controller 1 is used to control the lubricating oil replenishment device 3 to draw a portion of the lubricating oil from the compressor 2 into the lubricating oil replenishment device 3 after a first period of time following the start of the compressor 2, or when the exhaust temperature of the compressor 2 is greater than or equal to a first temperature threshold.

[0073] During the operation of the heat pump system, controller 1 is not only responsible for starting and monitoring the working status of compressor 2, but also for controlling the timing of the operation of the lubricating oil replenishment device 3. In order to ensure that compressor 2 receives proper lubrication and maintains its efficient operation, controller 1 is designed with a set of logic to control the lubricating oil intake process.

[0074] Specifically, controller 1 will automatically trigger the lubricating oil replenishment device 3 after a first set period (e.g., 60 minutes) following the start-up of compressor 2. This first set period is based on the time required for compressor 2 to start and for its internal oil to circulate sufficiently and reach an ideal lubrication state. By initiating the lubricating oil intake operation at this time, controller 1 can ensure that excess or insufficiently lubricated lubricating oil is promptly recovered after the initial break-in phase of compressor 2.

[0075] Furthermore, controller 1 also has the ability to monitor the discharge temperature of compressor 2 in real time. When the discharge temperature reaches or exceeds a first temperature threshold (e.g., 80 degrees Celsius), it means that compressor 2 may be experiencing excessive friction or insufficient lubrication. To prevent potential overheating and damage risks, controller 1 will immediately respond by instructing the lubricating oil replenishment device 3 to start, drawing some of the lubricating oil from compressor 2 into the device. This process not only helps to reduce the operating temperature of compressor 2, but also restores its lubrication performance by recovering and potentially reprocessing this lubricating oil, providing continuous lubrication support for compressor 2.

[0076] In one possible implementation, such as Figure 4 As shown, a first liquid level detection device 15 is provided in the cavity of the lubricating oil replenishment device 3, and the first liquid level detection device 15 is electrically connected to the controller 1.

[0077] The controller 1 is used to stop drawing lubricating oil from the compressor 2 into the lubricating oil replenishing device 3 when the liquid level of the lubricating oil replenishing device 3 reaches the position of the first liquid level detection device 15.

[0078] A first liquid level detection device 15 is installed inside the cavity of the lubricating oil replenishment device 3. The first liquid level detection device 15 is electrically connected to the controller 1, enabling the controller 1 to monitor the liquid level of the lubricating oil inside the cavity in real time.

[0079] The first liquid level detection device 15 constantly monitors the liquid level changes within the lubricating oil replenishment device 3. When the lubricating oil level in the cavity gradually rises and reaches the position of the first liquid level detection device 15, the first liquid level detection device 15 will immediately send a signal to the controller 1. Upon receiving this signal, the controller 1 will quickly react and stop the operation of drawing lubricating oil from the compressor 2 into the lubricating oil replenishment device 3.

[0080] By cooperating with the first liquid level detection device 15 and the controller 1, the lubricating oil replenishment device 3 can be kept within a safe liquid level range during operation. This not only helps maintain the stability of the heat pump system but also effectively extends the service life of the lubricating oil replenishment device 3 and avoids potential failures caused by abnormal liquid levels.

[0081] In one alternative implementation, such as Figure 5 As shown, the compressor 2 is equipped with a second liquid level detection device 16 and a third liquid level detection device 17. The position of the second liquid level detection device 16 is lower than the position of the third liquid level detection device 17. Both the second liquid level detection device 16 and the third liquid level detection device 17 are electrically connected to the controller 1.

[0082] The controller 1 is used to control the lubricating oil replenishing device 3 to replenish lubricating oil to the compressor 2 when the oil level in the compressor 2 is lower than the position of the second level detection device 16, and to control the lubricating oil replenishing device 3 to stop replenishing lubricating oil to the compressor 2 when the oil level in the compressor 2 reaches the position of the third level detection device 17, and to control the lubricating oil replenishing device 3 to draw a portion of the lubricating oil in the compressor 2 into the lubricating oil replenishing device 3 until the oil level in the compressor 2 is restored to the position of the second level detection device 16.

[0083] In the compressor 2, the core component of the heat pump system, two key liquid level detection devices are installed: a second liquid level detection device 16 and a third liquid level detection device 17. These two devices are located at different heights in the oil sump of the compressor 2, and both are electrically connected to the controller 1, enabling the controller 1 to monitor the liquid level in the oil sump in real time and accurately.

[0084] The second liquid level detection device 16 is located at a lower liquid level position. Its main function is to detect whether the compressor 2 is about to face the risk of insufficient lubricating oil. Once the liquid level in the oil sump drops below the second liquid level detection device 16, it means that the compressor 2 may not receive sufficient lubrication, thereby increasing the risk of wear and failure. At this time, the controller 1 will respond quickly and instruct the lubricating oil replenishment device 3 to start, replenishing the compressor 2 with an appropriate amount of lubricating oil to ensure its stable operation.

[0085] The third level detection device 17 is located at a higher level. Its function is to prevent the oil sump from becoming too high, which could lead to overflow or over-lubrication. When the oil sump level rises to the position of the third level detection device 17, the controller 1 will intervene again, this time instructing the lubricating oil replenishment device 3 to stop replenishing lubricating oil to the compressor 2 and to draw some of the lubricating oil from the compressor 2 into the lubricating oil replenishment device 3. This process will continue until the oil sump level returns to the position of the second level detection device 16, thereby ensuring that the lubricating oil in the compressor 2 is always maintained within an ideal range.

[0086] Through the coordinated operation of the second liquid level detection device 16 and the third liquid level detection device 17, and the intelligent control of the controller 1, it can be ensured that the compressor 2 receives proper lubrication under any operating conditions, thus avoiding wear caused by insufficient lubrication and preventing problems that may be caused by excessive lubrication.

[0087] In one alternative implementation, controller 1 is used to determine that the heat pump system is in a cold start state when the downtime of the heat pump system is greater than or equal to a second duration and the difference between the exhaust temperature of compressor 2 and the ambient temperature is less than or equal to a second temperature threshold.

[0088] Controller 1 is used to determine whether the heat pump system is in a cold start state when it is first started after being powered on.

[0089] In the intelligent control strategy of a heat pump system, controller 1 can not only adjust the system according to its real-time status, but also identify and respond to specific operating conditions, such as cold start. Cold start refers to the process of restarting the heat pump system after a long period of shutdown, especially when the ambient temperature is low. This process has a significant impact on the stability and energy efficiency of the heat pump system.

[0090] To accurately determine whether the heat pump system is in a cold start state, controller 1 is designed with a logical judgment mechanism. Controller 1 first determines the duration of the heat pump system's shutdown, and simultaneously, it also determines the difference between the exhaust temperature of compressor 2 and the ambient temperature. If the heat pump system's shutdown duration is greater than or equal to a second duration (e.g., 4 hours), and the difference between the exhaust temperature of compressor 2 and the ambient temperature is less than or equal to a second temperature threshold (e.g., 20 degrees Celsius), then controller 1 determines that the heat pump system is in a cold start state. This is because, under cold start conditions, the initial temperature of compressor 2 is usually close to the ambient temperature, and the difference between the exhaust temperature and the ambient temperature is small.

[0091] In addition to judging based on the difference between ambient temperature and compressor 2's exhaust temperature, controller 1 has another simple criterion: the first start-up of the heat pump system after power-on. Under any circumstances, as long as the heat pump system is starting for the first time after power-on, regardless of the ambient temperature and compressor 2's exhaust temperature, controller 1 will directly determine that the heat pump system is in a cold start state. This is because after a long period of shutdown, condensate may accumulate inside the heat pump system, and lubricating oil may have settled. Special control strategies are needed during the first start-up to ensure the smooth operation of the heat pump system.

[0092] In one possible implementation, the first entrance is located higher than the first exit.

[0093] The first inlet is designed to be positioned higher than the first outlet. This design is not arbitrary but based on specific functional requirements and the principles of fluid dynamics. When a fluid (such as gas or liquid) enters the lubricating oil replenishment device 3 or compressor 2 from the first inlet, it possesses a certain potential energy due to its higher position. As the fluid flows inside the lubricating oil replenishment device 3 or compressor 2, this potential energy gradually converts into kinetic energy, propelling the fluid forward.

[0094] When the fluid reaches the first outlet, its kinetic energy decreases due to its lower position, but by this time the fluid has already completed its predetermined flow within the lubricating oil replenishment device 3 or the compressor 2. This high-to-low design not only facilitates the natural flow of the fluid and reduces dependence on external energy, but also improves the efficiency and stability of the fluid flow to a certain extent.

[0095] In one alternative implementation, such as Figure 6 As shown, the heat pump system also includes an economizer 18, the main circuit of which is connected between the evaporator 4 and the condenser 5, and the auxiliary circuit of which is connected to the compressor 2.

[0096] In some advanced heat pump systems, economizers are often introduced to further improve their energy efficiency and operating performance.

[0097] Economizer 18 is a key component of the heat pump system, utilizing the energy difference in the refrigeration cycle. In this configuration, the main circuit of Economizer 18 is connected between evaporator 4 and condenser 5. This design allows the low-temperature, low-pressure refrigerant flowing from evaporator 4 to pass through the main circuit of Economizer 18 before undergoing its high-pressure, high-temperature conversion in condenser 5. During this process, the refrigerant undergoes an intermediate pressure increase and temperature decrease, better preparing it for the subsequent condensation process.

[0098] In addition to the main refrigerant circuit, the economizer 18 also has an auxiliary circuit that connects directly to the compressor 2. This auxiliary circuit allows some refrigerant to bypass the evaporator 4 and enter the economizer 18 directly from the high-pressure side of the compressor 2. Inside the economizer 18, this high-pressure refrigerant exchanges heat with the low-pressure refrigerant on the main circuit, thus achieving energy recovery and reuse. This process not only improves the refrigerant circulation efficiency but also helps reduce the energy consumption and wear of the compressor 2.

[0099] The technical solution of the present invention has been described in conjunction with the specific embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions resulting from these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A heat pump system, characterized in that, include: The system includes a controller, a compressor, a lubricating oil replenishment device, an evaporator, a condenser, and a four-way valve; the compressor, the four-way valve, the evaporator, and the condenser are connected in sequence, and the lubricating oil replenishment device is connected to the oil sump of the compressor. The lubricating oil replenishing device is used to replenish lubricating oil to the compressor, and to draw a portion of the lubricating oil in the compressor into the lubricating oil replenishing device; The controller is used to respond to a start command, control the compressor to start running, and determine whether the heat pump system is in a cold start state. If the heat pump system is in a cold start state, the controller controls the lubricating oil replenishment device to replenish lubricating oil to the compressor, and after replenishing the lubricating oil to the compressor, the controller controls the lubricating oil replenishment device to draw a portion of the lubricating oil in the compressor into the lubricating oil replenishment device.

2. The heat pump system according to claim 1, characterized in that, The lubricating oil replenishment device includes pipelines, a first valve, a second valve, a third valve, a fourth valve, and an oil pump. The first valve, the second valve, the third valve, the fourth valve, and the oil pump are all electrically connected to the controller. The pipeline includes a main line, a first branch line, and a second branch line. The main line includes a first inlet and a first outlet. The pipeline between the first inlet and the first outlet is located within the cavity of the lubricating oil replenishment device. The first inlet and the first outlet extend outside the cavity and connect to the oil sump of the compressor. A first valve is located outside the first inlet, and a second valve is located outside the first outlet. The oil pump is located on the main line within the cavity. One end of the first branch line connects to the position between the oil pump and the first inlet on the main line, and the other end connects to the cavity. A third valve is located on the first branch line. One end of the first branch line connects to the position between the oil pump and the first outlet on the main line, and the other end connects to the cavity. A fourth valve is located on the second branch line. The controller is used to control the first valve and the fourth valve to close, and to control the second valve, the third valve and the oil pump to open, so as to control the lubricating oil replenishment device to replenish lubricating oil to the compressor; The controller is used to close the second valve and the third valve, and to open the first valve, the fourth valve and the oil pump to draw some of the lubricating oil from the compressor into the lubricating oil replenishment device.

3. The heat pump system according to claim 2, characterized in that, The lubricating oil replenishing device includes a fifth valve, which is electrically connected to the controller. The pipeline includes a third branch, which is located outside the top opening of the lubricating oil replenishing device and connected to the gas separator of the compressor. The fifth valve is located on the third branch. The controller is used to control the fifth valve, the first valve, the second valve and the oil pump to open after a portion of the lubricating oil in the compressor is drawn into the lubricating oil replenishment device, so as to recover the gaseous refrigerant in the lubricating oil replenishment device to the gas separator of the compressor.

4. The heat pump system according to claim 3, characterized in that, An oil viscometer is installed in the cavity of the lubricating oil replenishment device, and the oil viscometer is electrically connected to the controller. The controller is used to detect the viscosity of the lubricating oil in the lubricating oil replenishment device cavity through the oil viscometer, and when the lubricating oil viscosity is lower than a preset threshold, it controls the fifth valve, the first valve, the second valve and the oil pump to open.

5. The heat pump system according to any one of claims 1-4, characterized in that, The controller is used to control the lubricating oil replenishment device to draw a portion of the lubricating oil from the compressor into the lubricating oil replenishment device after a first period of time following the start of the compressor, or when the exhaust temperature of the compressor is greater than or equal to a first temperature threshold.

6. The heat pump system according to claim 5, characterized in that, The lubricating oil replenishment device is equipped with a first liquid level detection device in its cavity, and the first liquid level detection device is electrically connected to the controller. The controller is used to stop drawing lubricating oil from the compressor into the lubricating oil replenishment device when the liquid level in the lubricating oil replenishment device reaches the position of the first liquid level detection device.

7. The heat pump system according to any one of claims 1-4, characterized in that, The compressor is equipped with a second liquid level detection device and a third liquid level detection device. The position of the second liquid level detection device is lower than the position of the third liquid level detection device. Both the second liquid level detection device and the third liquid level detection device are electrically connected to the controller. The controller is used to control the lubricating oil replenishment device to replenish lubricating oil to the compressor when the oil level in the compressor's oil sump is lower than the position of the second level detection device, and to control the lubricating oil replenishment device to stop replenishing lubricating oil to the compressor when the oil level in the compressor's oil sump reaches the position of the third level detection device, and to control the lubricating oil replenishment device to draw a portion of the lubricating oil in the compressor into the lubricating oil replenishment device until the oil level in the compressor's oil sump returns to the position of the second level detection device.

8. The heat pump system according to any one of claims 1-4, characterized in that, The controller is used to determine that the heat pump system is in a cold start state when the shutdown time of the heat pump system is greater than or equal to a second duration and the difference between the exhaust temperature of the compressor and the ambient temperature is less than or equal to a second temperature threshold. The controller is used to determine that the heat pump system is in a cold start state when it is first started after being powered on.

9. The heat pump system according to claim 2, characterized in that, The position of the first entrance is higher than the position of the first exit.

10. The heat pump system according to any one of claims 1-4, characterized in that, Also includes: An economizer, the main circuit of which is connected between the evaporator and the condenser, and the auxiliary circuit of which is connected to the compressor.

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