Temperature testing device and high-temperature heat pump starting control method

Abstract

The invention relates to the technical field of heat pumps, and discloses a temperature testing device and a high-temperature heat pump starting control method.The temperature testing device comprises a compressor, a guide pipe and a temperature sensor, and an oil cavity for containing lubricating oil is formed in the compressor; the guide pipe is inserted in the oil pouring opening and is in sealed connection with the oil pouring opening of the oil cavity, the temperature sensor is arranged in the guide pipe, and the end of the temperature sensor is immersed in the lubricating oil in the oil cavity through the guide pipe. Under the condition that the internal structure of the compressor is not changed, the guide pipe and the oil pouring opening are fused into a whole, the guide pipe and the oil pouring opening are fixedly connected in a sealed mode, the requirements for lubricating oil replacement and daily sealing are met, the guide pipe serves as a temperature measuring sleeve of a temperature sensor, the actual working temperature of lubricating oil can be more accurately measured in real time, and a heat pump system is safely started. The temperature testing device provided by the invention solves the problem that in the prior art, a refrigerant working medium in a compressor of a high-temperature heat pump cannot be completely gasified, so that hidden dangers exist in starting of a heat pump system.

Description

Technical Field

[0001] This invention relates to the field of heat pump technology, specifically to a temperature testing device and a high-temperature heat pump start-up control method. Background Technology

[0002] High-temperature heat pump technology can recover industrial waste heat, consuming a small amount of electricity to turn waste heat resources into steam for industrial heating. High-temperature heat pumps primarily use high-temperature refrigerants capable of high-temperature condensation, such as R245fa, R1233zde, R600a, R1336, and R601. These refrigerants generally have boiling points close to or higher than room temperature at normal pressure. When the high-temperature heat pump is off, the refrigerant in the system exists in liquid form. During startup, there is a risk that liquid refrigerant may remain in the compressor, potentially causing compressor liquid slugging failure.

[0003] In existing technologies, high-temperature heat pumps typically require external electric heating elements to fully preheat the entire compressor during cold starts, ensuring that the working fluid inside the compressor is completely vaporized before operation. Traditional high-temperature heat pump units achieve this process by setting a preheating time.

[0004] However, in the above scheme, the preheating time set by the heating belt cannot be automatically adjusted according to the ambient temperature and the state of the compressor itself. The refrigerant inside the compressor cannot be guaranteed to be completely vaporized, which leads to potential risks when starting the heat pump system. Summary of the Invention

[0005] This invention provides a temperature testing device and a high-temperature heat pump start-up control method to solve the problem that the refrigerant inside the compressor of a high-temperature heat pump cannot be guaranteed to be completely vaporized, which leads to potential risks when starting up the heat pump system.

[0006] In a first aspect, the present invention provides a temperature testing device, comprising: a compressor, a conduit, and a temperature sensor, wherein the compressor has an oil chamber for containing lubricating oil, and the compressor is provided with an oil drain port communicating with the oil chamber; the conduit is inserted into the oil drain port, the conduit is sealed to the oil drain port, the conduit extends toward the interior of the oil chamber, and at least its end is immersed in the lubricating oil in the oil chamber; the temperature sensor is embedded inside the conduit, and the test end of the temperature sensor is located at the end of the conduit.

[0007] Beneficial Effects: During use, the conduit is inserted into the oil chamber through the compressor's oil drain port, with the end of the conduit immersed in the lubricating oil within the chamber. This allows the testing end of the temperature sensor to be submerged in the lubricating oil. Without altering the compressor's internal structure, the conduit and oil drain port are integrated into a single structure, with a fixed, sealed connection, meeting the requirements for lubricating oil replacement and daily sealing. Simultaneously, the conduit serves as the temperature sensor's measuring sleeve, enabling more accurate measurement of the actual operating temperature of the lubricating oil. This allows for real-time monitoring of the refrigerant's start-up control within the compressor and the operating temperature of the lubricating oil under high-temperature operation. Real-time calculation of the refrigerant's superheat within the compressor allows for adjustment of the heating belt based on the oil temperature until all the refrigerant within the compressor has vaporized, ensuring the heat pump system meets start-up requirements and can be safely started. The temperature testing device provided by this invention solves the problem in existing technologies where the refrigerant inside the compressor of high-temperature heat pumps cannot be guaranteed to completely vaporize, leading to potential start-up hazards for the heat pump system.

[0008] In one optional embodiment, the conduit includes: a fixing part and an extension part, the fixing part being disposed at the oil outlet and fixedly and sealed to the oil outlet; the extension part being obliquely disposed in the oil cavity, the first end of the extension part communicating with the fixing part, the second end of the extension part extending to the bottom of the oil cavity, and the test end of the temperature sensor being disposed at the second end of the extension part.

[0009] Beneficial effects: By sealing and fixing the fixed part with the oil outlet, the extension part, which is inclined and set in the oil cavity, can extend the end of the extension part to the bottom of the oil cavity, thereby ensuring that the test end of the temperature sensor is immersed in the lubricating oil in the oil cavity, maintaining a stable contact state between the temperature sensor, the conduit and the lubricating oil, and keeping the three in a state of temperature balance, the accuracy of oil temperature measurement is greatly improved.

[0010] In one alternative embodiment, the extension is configured as a blind tube, and the second end of the extension is closed.

[0011] Beneficial effects: The extension of the blind tube can protect the temperature sensor immersed in the lubricating oil, and at the same time, it can meet the daily sealing requirements of the compressor oil chamber.

[0012] In one alternative implementation, the extension is configured as a flexible tube.

[0013] Beneficial effects: When vibration occurs during unit operation, the extension section uses a flexible tube, which can avoid the impact of vibration and other factors on the stable contact state of the temperature sensor, conduit and lubricating oil.

[0014] In one alternative embodiment, the fixing part is configured as a rigid tube.

[0015] Beneficial effects: The use of rigid tubing in the fixing part improves the stability of the connection between the fixing part and the oil outlet.

[0016] In one optional embodiment, a fixing member is provided at the oil outlet, the fixing member is threadedly connected to the oil outlet, and the fixing member has a limiting hole inside for the conduit to pass through.

[0017] Beneficial effects: The conduit passes through the limiting hole on the fixing component and is inserted into the oil drain port. The conduit and the oil drain port are connected by threads through the fixing component, so as to achieve a fixed and sealed connection between the conduit and the oil drain port. Without changing the internal structure of the compressor, the conduit and the oil drain port are integrated into a single structure, which meets the requirements of lubricating oil replacement and daily sealing.

[0018] In one optional embodiment, an annular connector protruding outward from the oil cavity is provided at the oil outlet, and the outer surface of the connector is provided with a first external thread; a mounting groove is provided at one end of the fixing member near the oil outlet, and an internal thread that mates with the first external thread of the connector is provided on the inner sidewall of the mounting groove.

[0019] Beneficial effect: The mounting groove on the fastener is fitted onto the connector, and the internal thread on the inner side wall of the mounting groove engages with the first external thread on the outer surface of the connector to achieve a threaded connection between the fastener and the connector.

[0020] In one alternative embodiment, a seal is provided at the bottom of the mounting groove, and the connector is press-fitted with the seal.

[0021] Beneficial effects: The sealing element can improve the sealing between the fixing parts and the connecting parts, and prevent oil leakage at the oil outlet.

[0022] In one alternative embodiment, the end of the fastener away from the oil outlet is provided with a second external thread for installing a sealing element.

[0023] Beneficial effect: The second external thread at the end of the fastener away from the oil outlet facilitates the installation of the sealing component, further improving the sealing effect.

[0024] Secondly, the present invention also provides a high-temperature heat pump start-up control method, which uses the temperature testing device described in the above-described embodiments, and includes the following steps: installing the temperature testing device, wherein the test end of the temperature sensor is placed inside the oil cavity through a conduit, so that the test end of the temperature sensor is immersed in the lubricating oil, and the temperature inside the oil cavity is detected; the detected oil temperature is combined with the compressor inlet pressure to calculate the superheat of the refrigerant inside the compressor in real time; when the superheat meets the set requirements, based on the principle of one-to-one correspondence between the refrigerant saturation pressure and saturation temperature, it is determined that all the refrigerant inside the compressor has vaporized, and the high-temperature heat pump is controlled to start.

[0025] Beneficial effects: The test end of the temperature sensor is immersed in the lubricating oil in the oil chamber through a conduit, directly and accurately monitoring the temperature inside the compressor's oil chamber. Combined with the compressor's inlet pressure, the superheat of the refrigerant inside the compressor can be calculated in real time. Based on the principle of one-to-one correspondence between the refrigerant's saturation pressure and saturation temperature, it can be determined whether the refrigerant inside the compressor has been completely vaporized, so that the high-temperature heat pump meets the start-up requirements and can be started safely. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a temperature testing device according to an embodiment of the present invention; Figure 2 for Figure 1 An enlarged schematic diagram of part A in the middle; Figure 3 Figure 2 A cross-sectional schematic diagram of the central conduit.

[0028] Explanation of reference numerals in the attached figures: 1. Compressor; 2. Oil inlet; 3. Pipe; 4. Fixing part; 5. Extension part; 6. Fixing element; 7. Internal thread; 8. Seal; 9. Second external thread. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0030] In related technologies, the method for testing the temperature of the lubricating oil in the oil tank at the bottom of compressor 1 involves attaching a temperature sensor to the outside of the bottom of compressor 1. However, the temperature sensor is cylindrical and can only form a line contact with the outer casing of compressor 1, resulting in a very small contact area. If the temperature sensor is slightly loose (such as due to vibrations generated during unit operation), it will cause poor contact or even separation between the temperature sensor and the bottom of compressor 1, which will seriously affect the accuracy of the actual temperature measurement and cause control misjudgment.

[0031] The following is combined Figures 1 to 3 The following describes embodiments of the present invention.

[0032] According to an embodiment of the present invention, a temperature testing device is provided, comprising: a compressor 1, a conduit 3, and a temperature sensor. The compressor 1 has an oil chamber for containing lubricating oil, and the compressor 1 is provided with an oil drain port 2 communicating with the oil chamber. The conduit 3 is inserted into the oil drain port 2 and is sealed to the oil drain port 2. The conduit 3 extends toward the interior of the oil chamber, and at least its end is immersed in the lubricating oil in the oil chamber. The temperature sensor is embedded inside the conduit 3, and the test end of the temperature sensor is located at the end of the conduit 3.

[0033] In use, the conduit 3 is inserted into the oil chamber through the oil drain port 2 of the compressor 1, with the end of the conduit 3 immersed in the lubricating oil within the oil chamber. This allows the test end of the temperature sensor to be immersed in the lubricating oil. Without altering the internal structure of the compressor 1, the conduit 3 and the oil drain port 2 are integrated into a single structure. The conduit 3 and the oil drain port 2 are fixedly and sealed together, meeting the requirements for lubricating oil replacement and daily sealing. Simultaneously, the conduit 3 serves as the temperature-sensing sleeve for the temperature sensor, enabling more accurate measurement of the actual operating temperature of the lubricating oil. This allows for real-time monitoring of the refrigerant's start-up control within the compressor 1 and the operating temperature of the lubricating oil under high-temperature operation. It also allows for real-time calculation of the refrigerant's superheat within the compressor 1, and adjustment of the heating belt based on the oil temperature until all the refrigerant within the compressor 1 is vaporized, ensuring the heat pump system meets start-up requirements and can be safely started. The temperature testing device provided in this embodiment solves the problem in existing technologies where the refrigerant inside the compressor 1 of high-temperature heat pumps cannot be guaranteed to be completely vaporized, leading to potential start-up hazards for the heat pump system.

[0034] It should be further explained that the temperature sensor is connected to the control module, and the control module is connected to the heating device on the compressor 1. The temperature data detected by the temperature sensor in real time is transmitted to the control module. The control module integrates the data and calculates the superheat of the refrigerant inside the compressor 1 in real time. When the superheat meets the specified requirements (8~10℃), according to the principle of one-to-one correspondence between the saturation pressure and saturation temperature of the refrigerant, the refrigerant inside the compressor 1 can be automatically determined to have been completely vaporized, and the heat pump system can be safely started up if the start-up requirements are met.

[0035] In one embodiment, the conduit 3 includes a fixing part 4 and an extension part 5. The fixing part 4 is disposed at the oil outlet 2 and is fixedly and sealed to the oil outlet 2. The extension part 5 is inclinedly disposed in the oil cavity. The first end of the extension part 5 communicates with the fixing part 4, and the second end of the extension part 5 extends to the bottom of the oil cavity. The test end of the temperature sensor is disposed at the second end of the extension part 5. By sealing and fixing the fixing part 4 to the oil outlet 2, and by inclinedly disposing the extension part 5 in the oil cavity, the end of the extension part 5 can extend to the bottom of the oil cavity, thereby ensuring that the test end of the temperature sensor is immersed in the lubricating oil in the oil cavity. This maintains a stable contact state between the temperature sensor, the conduit 3, and the lubricating oil, ensuring that the three are in a temperature equilibrium state, and greatly improving the accuracy of oil temperature measurement. Specifically, the fixing part 4 is disposed horizontally. Alternatively, as an alternative embodiment, the fixing part 4 can also be disposed perpendicular to the extension part 5, that is, the extension part 5 is disposed vertically.

[0036] In one embodiment, the extension 5 is configured as a blind pipe, with its second end closed. The extension 5 of the blind pipe protects the temperature sensor immersed in the lubricating oil and also meets the daily sealing requirements of the compressor 1's oil chamber. Alternatively, as an alternative embodiment, the extension 5 can also be configured as a connecting pipe.

[0037] In one embodiment, the extension 5 is configured as a flexible tube. When vibration occurs during unit operation, the flexible tube in the extension 5 prevents vibration and other factors from affecting the stable contact between the temperature sensor, the conduit 3, and the lubricating oil. Alternatively, as an alternative implementation, the extension 5 can also be configured as a rigid tube.

[0038] Specifically, the extension 5 is configured as a flexible metal blind tube.

[0039] In one embodiment, the fixing part 4 is a rigid tube. Using a rigid tube for the fixing part 4 improves the stability of the connection between the fixing part 4 and the oil outlet 2. Alternatively, as an alternative embodiment, the fixing part 4 can also be a flexible tube.

[0040] Specifically, the fixing part 4 is a rigid metal tube.

[0041] In one embodiment, a fixing member 6 is provided at the oil drain port 2. The fixing member 6 is threadedly connected to the oil drain port 2, and a limiting hole is provided inside the fixing member 6 for the conduit 3 to pass through. The conduit 3 passes through the limiting hole on the fixing member 6 and is inserted into the oil drain port 2. The threaded connection between the fixing member 6 and the oil drain port 2 achieves a fixed and sealed connection between the conduit 3 and the oil drain port 2. Without changing the internal structure of the compressor 1, the conduit 3 and the oil drain port 2 are integrated into a single structure, meeting the requirements for lubricating oil replacement and daily sealing. Alternatively, as an alternative embodiment, the fixing member 6 and the oil drain port 2 can also be connected by other detachable fixing methods such as interference fit or snap fit.

[0042] In one embodiment, an annular connector protruding outward from the oil cavity is provided at the oil outlet 2, and the outer surface of the connector is provided with a first external thread; the fixing member 6 is provided with a mounting groove at one end near the oil outlet 2, and the inner sidewall of the mounting groove is provided with an internal thread 7 that mates with the first external thread of the connector. The mounting groove on the fixing member 6 is fitted onto the connector, and the threaded connection between the fixing member 6 and the connector is achieved by the engagement of the internal thread 7 on the inner sidewall of the mounting groove with the first external thread on the outer surface of the connector. Alternatively, as an alternative embodiment, the first external thread is provided at the end of the fixing member 6 near the oil outlet 2, and the internal thread 7 is provided on the inner sidewall of the connector.

[0043] In one embodiment, a sealing element 8 is provided at the bottom of the mounting groove, and the connector is press-fitted with the sealing element 8. The sealing element 8 improves the sealing performance between the fixing element 6 and the connector, preventing oil leakage at the oil outlet 2.

[0044] In one embodiment, the end of the fixing member 6 away from the oil outlet 2 is provided with a second external thread 9 for installing a sealing member. The second external thread 9 at the end of the fixing member 6 away from the oil outlet 2 facilitates the installation of the sealing member, further improving the sealing effect. Alternatively, as an alternative embodiment, the second external thread 9 can be omitted, and the sealing member is snap-fitted into the fixing member 6.

[0045] According to an embodiment of the present invention, another aspect provides a high-temperature heat pump start-up control method, which employs the temperature testing device described in the above embodiment, and includes the following steps: installing the temperature testing device, wherein the test end of the temperature sensor is placed inside the oil cavity through the conduit 3, so that the test end of the temperature sensor is immersed in the lubricating oil, and the temperature inside the oil cavity is detected; the detected oil temperature is combined with the inlet pressure of the compressor 1 to calculate the superheat of the refrigerant inside the compressor 1 in real time; when the superheat meets the set requirements, according to the principle of one-to-one correspondence between the saturation pressure and saturation temperature of the refrigerant, it is determined that all the refrigerant inside the compressor 1 has vaporized, and the high-temperature heat pump is controlled to start.

[0046] The test end of the temperature sensor is immersed in the lubricating oil in the oil chamber through the conduit 3, directly and accurately monitoring the temperature inside the oil chamber of the compressor 1. Combined with the inlet pressure of the compressor 1, the superheat of the refrigerant inside the compressor 1 can be calculated in real time. Based on the principle of one-to-one correspondence between the saturation pressure and saturation temperature of the refrigerant, it is determined whether the refrigerant inside the compressor 1 has been completely vaporized, so that the high-temperature heat pump meets the start-up requirements and can be started safely.

[0047] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A temperature testing device, characterized in that, include: The compressor (1) has an oil chamber inside that contains lubricating oil, and the compressor (1) is provided with an oil drain port (2) that communicates with the oil chamber. A conduit (3) is inserted into the oil outlet (2), the conduit (3) is fixedly and sealed to the oil outlet (2), the conduit (3) extends toward the interior of the oil cavity, and at least the end of the conduit (3) is immersed in the lubricating oil in the oil cavity; A temperature sensor is embedded inside the conduit (3), and the test end of the temperature sensor is located at the end of the conduit (3).

2. The temperature testing device according to claim 1, characterized in that, The catheter (3) includes: A fixing part (4) is provided at the oil outlet (2), and the fixing part (4) is fixedly and sealed to the oil outlet (2); An extension (5) is inclinedly disposed in the oil cavity. The first end of the extension (5) is connected to the fixing part (4), and the second end of the extension (5) extends to the bottom of the oil cavity. The test end of the temperature sensor is disposed at the second end of the extension (5).

3. The temperature testing device according to claim 2, characterized in that, The extension (5) is configured as a blind tube, and the second end of the extension (5) is closed.

4. The temperature testing device according to claim 3, characterized in that, The extension (5) is configured as a flexible tube.

5. The temperature testing device according to claim 2, characterized in that, The fixing part (4) is a rigid tube.

6. The temperature testing device according to any one of claims 1-5, characterized in that, A fixing member (6) is provided at the oil outlet (2). The fixing member (6) is threadedly connected to the oil outlet (2). The fixing member (6) has a limiting hole inside for the conduit (3) to pass through.

7. The temperature testing device according to claim 6, characterized in that, An annular connector protruding outward from the oil cavity is provided at the oil outlet (2), and the outer surface of the connector is provided with a first external thread; The fixing member (6) has an installation groove at one end near the oil outlet (2), and the inner wall of the installation groove has an internal thread (7) that mates with the first external thread of the connector.

8. The temperature testing device according to claim 7, characterized in that, A sealing element (8) is provided at the bottom of the mounting groove, and the connector is pressed against the sealing element (8).

9. The temperature testing device according to claim 6, characterized in that, The end of the fixing member (6) away from the oil outlet (2) is provided with a second external thread (9) for installing the sealing member.

10. A high-temperature heat pump start-up control method, employing the temperature testing device according to any one of claims 1-9, characterized in that, Includes the following steps: Install a temperature testing device. The test end of the temperature sensor is set inside the oil cavity through a conduit (3), so that the test end of the temperature sensor is immersed in the lubricating oil to detect the temperature inside the oil cavity. The detected oil temperature, combined with the compressor (1) inlet pressure, is used to calculate the superheat of the refrigerant inside the compressor (1) in real time. When the superheat meets the set requirements, based on the principle of one-to-one correspondence between the refrigerant saturation pressure and saturation temperature, it is determined that all the refrigerant inside the compressor (1) has been vaporized, and the high-temperature heat pump is controlled to start.

Images