Compressor with oil level detection device
Patent Information
- Application Number
- CN202521199536.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-11
- Publication Date
- 2026-09-22
- Estimated Expiration
- 2035-06-11
AI Technical Summary
但是，将传感器安装在压缩机壳体的内部，由于压缩机壳体的内部空间小，且需要安装电子组件、压缩组件等核心部件，容易导致传感器安装困难、成本较高等问题；并且，压缩机在运作过程中，由于其内部的油面波动较大，传感器容易存在检测困难、检测不准确等问题
[0013]由此，根据本实用新型的带油位检测装置的压缩机，通过温度传感器、压力传感器测量冷冻机油在压缩机运转时由于高温、压力元素的影响下而改变的介电常数ε(T，P)，利用油位传感器对冷冻机油所测量的电容值C＝A+B*L*{ε(T，P)-E}，由该公式可知，油位传感器的两个检测电极插入到冷冻机油的高度L与电容值C呈线性关系，通过测得的电容值C可得出油位传感器的两个检测电极插入到冷冻机油的高度L，进而推算出油池的油位高度，使得本实用新型实施例能够准确地检测到压缩机壳体内部的冷冻机油的油位高低，并在温度传感器、压力传感器的作用下实时修正冷冻机油的介电常数，使得测量的数据更为准确。
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Figure CN224785938U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of compressor technology, and in particular to a compressor with an oil level detection device. Background Technology
[0002] A compressor has a compression assembly that draws in and compresses the refrigerant, and an electronic assembly located in the upper part of the compressor housing that acts on the compression assembly. The compression assembly and the electronic assembly share a rotating shaft, which rotates based on electricity generated by the electronic assembly. A piston on the rotating shaft compresses the refrigerant within the internal cavity of the compression assembly. In this configuration, refrigerant oil needs to be supplied to components such as the bearings and crankshaft of the compression assembly. The refrigerant oil is generally stored in the lower part of the compressor housing, primarily serving a lubricating function and cooling the electronic components. The quantity and condition of the refrigerant oil inside the compressor housing, such as its dilution rate and viscosity, cannot be guaranteed to be adjusted within a specific range, which can lead to abnormal wear or even malfunction of the compressor.
[0003] Therefore, accurately detecting the oil level inside a compressor is not an easy task, which is why most compressors do not have related oil level detection devices installed. While some compressors do have internal oil level sensors to detect the oil level, installing the sensor inside the compressor housing presents challenges. The limited internal space of the compressor housing, coupled with the need to house electronic components and other core components, leads to difficulties in sensor installation and high costs. Furthermore, during compressor operation, the significant fluctuations in the oil level can cause detection difficulties and inaccuracies. Utility Model Content
[0004] Based on this, the purpose of this utility model is to overcome the shortcomings of the prior art and provide a compressor with an oil level detection device. This oil level detection device is inexpensive and can accurately detect the oil level of the refrigeration oil in the compressor. When the oil level is abnormal, the compressor can restore the normal oil level through system logic, such as reducing the frequency, controlling the oil return, or stopping the compressor, thereby ensuring the smooth operation of the compressor, avoiding problems such as oil shortage and abnormal wear, and thus improving the service life of the compressor.
[0005] To achieve the above objectives, this utility model provides a compressor with an oil level detection device. The compressor includes a compressor housing and a control system. The lower part of the compressor housing contains an oil sump for storing refrigeration oil, and the interior of the compressor housing above the oil sump is a cavity.
[0006] The oil level detection device includes an oil level sensor and a temperature sensor. At least part of the oil level sensor is inserted into the refrigeration oil in the oil sump to detect the oil level height in the oil sump. The temperature sensor is used to directly or indirectly detect the temperature of the refrigeration oil.
[0007] The control system is connected to the oil level sensor and the temperature sensor respectively. During the operation of the compressor, the control system is used to acquire the capacitance signal of the oil level sensor and the temperature signal of the temperature sensor in real time, adjust the capacitance signal of the oil level sensor in real time according to the acquired temperature signal, and output the calibrated oil level height value.
[0008] Wherein, the oil level sensor is inserted to a height L into the refrigeration oil, and the oil level sensor is used to measure the capacitance value C that changes according to the oil level of the refrigeration oil inside the compressor housing. The temperature sensor is used to directly or indirectly measure the temperature difference ΔT that changes according to the temperature of the refrigeration oil. The dielectric constant of the refrigeration oil when the compressor is running is ε(T), satisfying the following relationship:
[0009] C=A+B*L*{ε(T)-E},ε(T)=ε(1+αΔT+βΔT 2 ); where A and B are constants, E is the dielectric constant of air, ε is the reference dielectric constant of refrigeration oil, and α and β are the temperature coefficients of refrigeration oil.
[0010] Furthermore, the oil level detection device also includes a pressure sensor, which is disposed in the cavity of the compressor housing. The pressure sensor is used to measure the pressure difference ΔP that changes according to the internal pressure of the compressor housing. The dielectric constant of the refrigeration oil during compressor operation is ε(T, P), satisfying the following relationship:
[0011] C=A+B*L*{ε(T, P)-E}, ε(T, P)=ε(1+αΔT+βΔT 2 )(1+γΔP), where γ is the pressure sensitivity coefficient.
[0012] In one embodiment, the oil level sensor includes a first detection electrode and a second detection electrode with identical structures. The first detection electrode and the second detection electrode are respectively inserted into the refrigerant oil inside the compressor housing, and the height of the portion of the first detection electrode and the second detection electrode inserted into the refrigerant oil of the compressor housing is L; the distance between the first detection electrode and the second detection electrode is d; the width of the first detection electrode and the second detection electrode is b; and the length of the first detection electrode and the second detection electrode is H, satisfying the relationships: A=b*H*E / d, B=b / d.
[0013] Therefore, according to the compressor with oil level detection device of this utility model, the dielectric constant ε(T, P) of the refrigeration oil changes due to the influence of high temperature and pressure elements when the compressor is running, through temperature and pressure sensors. The capacitance value C measured by the oil level sensor is C = A + B * L * {ε(T, P) - E}. From this formula, it can be seen that the height L of the two detection electrodes of the oil level sensor inserted into the refrigeration oil is linearly related to the capacitance value C. By measuring the capacitance value C, the height L of the two detection electrodes of the oil level sensor inserted into the refrigeration oil can be obtained, and then the oil level height of the oil sump can be calculated. This allows the embodiment of this utility model to accurately detect the oil level of the refrigeration oil inside the compressor housing, and corrects the dielectric constant of the refrigeration oil in real time under the action of temperature and pressure sensors, making the measured data more accurate.
[0014] In one embodiment, the oil level sensor is a capacitive sensor, and multiple oil level sensors are connected in parallel on the compressor housing. The total capacitance of the multiple oil level sensors is D, where D = N*C, and N is the number of oil level sensors.
[0015] In one embodiment, the temperature sensor is disposed in the oil sump of the compressor housing.
[0016] In one embodiment, a wiring terminal is provided on the outer wall of the compressor housing, and the wiring terminal is electrically connected to the oil level sensor.
[0017] In one embodiment, the terminal block extends into the interior of the compressor housing, and the portion of the terminal block extending into the compressor housing is interference-fitted with the oil level sensor to form an electrical connection.
[0018] In one embodiment, the refrigeration oil is at least one of POE oil and PVE oil, or a mixture thereof.
[0019] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description
[0020] Figure 1 This is one of the structural schematic diagrams of a compressor with an oil level detection device according to an embodiment of the present utility model;
[0021] Figure 2 This is a second schematic diagram of the compressor with an oil level detection device according to an embodiment of the present invention;
[0022] Figure 3 This is one of the structural schematic diagrams of the oil level sensor according to an embodiment of the present utility model;
[0023] Figure 4 This is a second schematic diagram of the structure of the oil level sensor according to an embodiment of the present invention;
[0024] Figure 5 This is a schematic diagram of the oil level sensor according to an embodiment of the present invention.
[0025] Figure 6 This is the third schematic diagram of the structure of the oil level sensor according to an embodiment of the present invention.
[0026] Explanation of reference numerals in the attached drawings: 10, compressor housing; 11, oil sump; 12, cavity; 13, first connecting pipe; 14, second connecting pipe; 20, oil level sensor; 21, first detection electrode; 22, second detection electrode; 30, temperature sensor; 40, pressure sensor. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of this application clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0028] The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “the,” and “the” used in this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.
[0029] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0030] In related technologies, a compressor has a compression assembly that draws in and compresses refrigerant, and an electronic assembly located in the upper part of the compressor housing that acts on the compression assembly. The compression assembly and the electronic assembly share a rotating shaft, which rotates based on electricity generated by the electronic assembly. A piston on the rotating shaft compresses the refrigerant within the internal cavity of the compression assembly. In this case, refrigerant oil needs to be supplied to components such as bearings and crankshafts of the compression assembly. The refrigerant oil is generally stored in the lower part of the compressor housing, primarily performing lubrication and cooling functions for the electronic components. Therefore, ensuring that the level of refrigerant oil inside the compressor housing remains within a standard range is crucial. However, accurately detecting the refrigerant oil level inside the compressor is not easy, which has led to most compressors not being equipped with relevant oil level detection devices. Some other compressors, while having internal oil level sensors to detect the refrigerant oil level, do have such sensors. However, installing the sensor inside the compressor housing presents challenges due to the limited internal space and the need to accommodate core components such as electronic and compression components. This can lead to difficulties in sensor installation and higher costs. Furthermore, during compressor operation, the significant fluctuations in the oil level can cause problems such as difficulty in sensor detection and inaccurate readings.
[0031] Therefore, this utility model embodiment provides a compressor with an oil level detection device. According to this utility model embodiment, the oil level detection device is inexpensive and can accurately detect the level of refrigeration oil in the compressor.
[0032] Please see Figures 1 to 6 This utility model embodiment provides a compressor with an oil level detection device. The compressor includes a compressor housing 10 and a control system. The lower part of the compressor housing 10 is an oil sump 11 for storing refrigeration oil, and the interior of the compressor housing 10 above the oil sump 11 is a cavity 12. The oil level detection device includes an oil level sensor 20 and a temperature sensor 40. At least part of the oil level sensor 20 is inserted into the refrigeration oil in the oil sump 11 to detect the oil level height of the oil sump 11. The temperature sensor 30 is used to directly or indirectly detect the temperature of the refrigeration oil. The control system is connected to the oil level sensor 20 and the temperature sensor 30 respectively. During the operation of the compressor, the control system is used to acquire the capacitance signal of the oil level sensor 20 and the temperature signal of the temperature sensor 30 in real time, adjust the capacitance signal of the oil level sensor 20 in real time according to the acquired temperature signal, and output the calibrated oil level height value.
[0033] The oil level sensor 20 is inserted to a height L into the refrigeration oil. The oil level sensor 20 measures the capacitance C, which changes according to the oil level inside the compressor housing 10. The temperature sensor 30 is used to directly or indirectly measure the temperature difference ΔT, which changes according to the temperature of the refrigeration oil. The dielectric constant of the refrigeration oil during compressor operation is ε(T), satisfying the following relationship:
[0034] C=A+B*L*{ε(T)-E},ε(T)=ε(1+αΔT+βΔT 2 ); where A and B are constants, E is the dielectric constant of air, ε is the reference dielectric constant of refrigeration oil, and α and β are the temperature coefficients of refrigeration oil.
[0035] Furthermore, the oil level detection device also includes a pressure sensor 40, which is disposed in the cavity 12 of the compressor housing 10. The pressure sensor 40 is used to measure the pressure difference ΔP that changes according to the internal pressure of the compressor housing 10. The dielectric constant of the refrigeration oil during compressor operation is ε(T, P), which satisfies the following relationship:
[0036] C=A+B*L*{ε(T, P)-E}, ε(T, P)=ε(1+αΔT+βΔT 2 )(1+γΔP), where γ is the pressure sensitivity coefficient.
[0037] It can be understood that since the dielectric constant of refrigeration oil is only slightly affected by temperature and pressure, this embodiment of the invention uses temperature sensor 40 and pressure sensor 50 to measure the temperature and pressure changes of refrigeration oil during compressor operation, thereby correcting the dielectric constant of the refrigeration oil and making the capacitance measurement results more accurate.
[0038] In this embodiment of the invention, the oil level sensor 20 is a capacitive sensor. The oil level sensor 20 includes a first detection electrode 21 and a second detection electrode 22 with identical structures. The first detection electrode 21 and the second detection electrode 22 are respectively inserted into the refrigerant oil inside the compressor housing 10, and the height of the portion of the first detection electrode 21 and the second detection electrode 22 inserted into the refrigerant oil of the compressor housing 10 is L; the distance between the first detection electrode 21 and the second detection electrode 22 is d; the width of both the first detection electrode 21 and the second detection electrode 22 is b; and the length of both the first detection electrode 21 and the second detection electrode 22 is H. Then, the capacitance value C measured by the oil level sensor 20 satisfies the following relationship:
[0039] C={E*b*(HL) / d}+{ε(T,P)*b*L / d}={b*H*E / d}+{ε(T,P)-E}*L*b / d;
[0040] That is: C=A+B*L*{ε(T,P)-E}, where A=b*H*E / d, B=b / d, and A and B are both constants.
[0041] Where α is the linear temperature coefficient of the refrigeration oil and β is the nonlinear temperature coefficient of the refrigeration oil, the values of which depend on the dielectric material of the refrigeration oil. For example, if the refrigeration oil is a non-polar oil, α = 10. -4 ~10 -3 K -1 β = 0; when the refrigeration oil is mineral oil, α = 2.3 × 10⁻⁶. -4 K -1 When the refrigeration oil is a polar oil (such as ester oil, POE oil, PVE oil), α = 10 -3 ~10 -2 K -1 β = 10 -6 ~10 -5 K -2 In some embodiments of this invention, when the refrigeration oil is pentaerythritol ester, α = 5.8 × 10⁻⁶. -3 K -1 β=3.2×10 -6 K -2 .
[0042] Therefore, according to the compressor with oil level detection device of this utility model, the dielectric constant ε(T, P) of the refrigeration oil changes due to the influence of high temperature and pressure elements when the compressor is running, through temperature sensor 30 and pressure sensor 40. The capacitance value C of the refrigeration oil measured by oil level sensor 20 is C=A+B*L*{ε(T, P)-E}. From this formula, it can be seen that the height L of the two detection electrodes of oil level sensor 20 inserted into the refrigeration oil is linearly related to the capacitance value C. The height L of the two detection electrodes of oil level sensor 20 inserted into the refrigeration oil can be obtained by measuring the capacitance value C, and then the oil level height of oil sump 11 can be calculated. This allows the embodiment of this utility model to accurately detect the oil level of refrigeration oil inside the compressor housing 10, and corrects the dielectric constant of refrigeration oil in real time under the action of temperature sensor 30 and pressure sensor 40, making the measured data more accurate.
[0043] In some embodiments of this utility model, a plurality of oil level sensors 20 are connected in parallel on the compressor housing 10, and the total capacitance of the plurality of oil level sensors 20 is D, D = N*C, where N is the number of oil level sensors 20.
[0044] It can be understood that the number of oil level sensors 20 in this utility model can be designed to be one, two, or more, depending on actual needs.
[0045] The oil level sensor 30 can be a 23B1 oil level sensor 30 manufactured by Seikaku Co., Ltd., or another type of oil level sensor 30. Furthermore, the refrigeration oil is at least one of POE oil and PVE oil, or a mixture thereof. Moreover, the temperature sensor 40 is disposed in the oil sump 11 inside the compressor housing 10, and the pressure sensor 50 can be disposed inside the top cover of the compressor housing 10 or on the side wall of the compressor housing 10 near the exhaust pipe.
[0046] Optionally, in some embodiments of this utility model, a wiring terminal 23 is provided on the outer wall of the compressor housing 10, and the wiring terminal 23 is electrically connected to the oil level sensor 20. Specifically, a portion of the wiring terminal 23 extends into the interior of the compressor housing 10, and the portion of the wiring terminal 23 extending into the compressor housing 10 is interference-fitted with the oil level sensor 20 to form an electrical connection.
[0047] Furthermore, in these embodiments, the top of the oil level sensor 20 is provided with two metal clips, which are respectively connected to the first detection electrode 21 and the second detection electrode 22. Two terminals 23 are respectively provided on the outer side wall of the compressor housing 10, and the two terminals 23 are respectively inserted into the two metal clips of the oil level sensor 20, thereby making the terminals 23 electrically connected to the oil level sensor 20.
[0048] Furthermore, relatively accurate dielectric constant ε(T, P) data, along with temperature T and pressure P, were obtained, which can be used to calculate the dilution rate of compressor oil by the refrigerant and to estimate oil viscosity. For example, under the same environmental conditions, the dielectric constant of the refrigerant is generally lower, while that of the oil is higher. When the oil is diluted by the refrigerant, the dielectric constant decreases. Therefore, the relatively accurate dielectric constant ε obtained through the above method can be used to calculate the oil dilution rate under specific conditions. Within a certain dilution range, there is a good linear relationship between the oil dilution rate and Δε. Therefore, oil dilution rate (%) = K*(ε_oil - ε_sampal) = K*Δε, where ε_oil is the reference dielectric constant, i.e., the dielectric constant under specific operating conditions, ε_sampal is the measured dielectric constant, and K is a scaling factor. Similarly, through numerous experiments, changes in the dielectric constant can also be used to infer the viscosity of the oil.
[0049] Optionally, in some embodiments of this utility model, two metal wires can be led out from the oil level sensor 20, and the two metal wires can extend outside the compressor housing 10. In this way, the oil level sensor 20 can be connected to the control system in the outside through the two metal wires.
[0050] The above embodiments can accurately detect the oil level of the compressor's refrigeration oil. When the oil level is abnormal, the system logic can restore the compressor to a normal oil level through methods such as reducing the frequency, controlling oil return, or stopping the compressor. This ensures stable operation of the compressor, avoids problems such as oil shortage and abnormal wear, and thus extends the compressor's service life.
[0051] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of the compressor with oil level detection device of this utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.
Claims
1. A compressor with an oil level detection device, characterized in that: The compressor includes a compressor housing and a control system. The lower interior of the compressor housing contains an oil sump for storing refrigeration oil, and the interior of the compressor housing above the oil sump is a cavity. The oil level detection device includes an oil level sensor and a temperature sensor. At least part of the oil level sensor is inserted into the refrigeration oil in the oil sump to detect the oil level height in the oil sump. The temperature sensor is used to directly or indirectly detect the temperature of the refrigeration oil. The control system is connected to the oil level sensor and the temperature sensor respectively. During the operation of the compressor, the control system is used to acquire the capacitance signal of the oil level sensor and the temperature signal of the temperature sensor in real time, adjust the capacitance signal of the oil level sensor in real time according to the acquired temperature signal, and output the calibrated oil level height value.
2. The compressor with oil level detection device according to claim 1, characterized in that: The oil level sensor is inserted to a height L into the refrigeration oil. The oil level sensor measures the capacitance C, which changes according to the oil level inside the compressor housing. The temperature sensor measures the temperature difference ΔT, which changes according to the temperature of the refrigeration oil. The dielectric constant of the refrigeration oil during compressor operation is ε(T), satisfying the following relationship: C=A+B*L*{ε(T)-E},ε(T)=ε(1+αΔT+βΔT 2 ); where A and B are constants, E is the dielectric constant of air, ε is the reference dielectric constant of refrigeration oil, and α and β are the temperature coefficients of refrigeration oil.
3. The compressor with oil level detection device according to claim 1, characterized in that: The oil level detection device also includes a pressure sensor, which is disposed in the cavity of the compressor housing. The pressure sensor is used to measure the pressure difference ΔP that changes according to the internal pressure of the compressor housing. The dielectric constant of the refrigeration oil during compressor operation is ε(T, P), which satisfies the following relationship: C=A+B*L*{ε(T, P)-E}, ε(T, P)=ε(1+αΔT+βΔT 2 )(1+γΔP), where γ is the pressure sensitivity coefficient.
4. The compressor with oil level detection device according to claim 1, characterized in that: The oil level sensor includes a first detection electrode and a second detection electrode with identical structures. The first detection electrode and the second detection electrode are respectively inserted into the refrigeration oil inside the compressor housing, and the height of the portion of the first detection electrode and the second detection electrode inserted into the refrigeration oil of the compressor housing is L. The distance between the first detection electrode and the second detection electrode is d, the width of the first detection electrode and the second detection electrode is b, and the length of the first detection electrode and the second detection electrode is H, satisfying the relationship: A=b*H*E / d, B=b / d.
5. The compressor with oil level detection device according to claim 2, characterized in that: The oil level sensor is a capacitive sensor, and multiple oil level sensors are connected in parallel on the compressor housing. The total capacitance of the multiple oil level sensors is D, where D = N*C, and N is the number of oil level sensors.
6. The compressor with oil level detection device according to claim 1, characterized in that: The temperature sensor is installed in the oil sump of the compressor housing.
7. The compressor with oil level detection device according to claim 1, characterized in that: A wiring terminal is provided on the outer wall of the compressor housing, and the wiring terminal is electrically connected to the oil level sensor.
8. The compressor with oil level detection device according to claim 7, characterized in that: The terminal block extends into the compressor housing, and the portion of the terminal block extending into the compressor housing is interference-fitted with the oil level sensor to form an electrical connection.
9. The compressor with oil level detection device according to claim 1, characterized in that: The refrigeration oil is at least one of POE oil and PVE oil, or a mixture thereof.