Composite cooling method for supercharging equipment, supercharging medium and control system of supercharging medium

Abstract

The invention relates to a composite cooling method for supercharging equipment, a supercharging medium and a control system thereof, and relates to the field of compressor cooling, a compressor is started to supercharge natural gas in a low-temperature and low-pressure area to a high-temperature and high-pressure area, and an air-cooled heat exchanger is started to reduce the high-temperature and high-pressure natural gas output by the compressor to high-pressure natural gas of 50 + / -2 DEG C; when the temperature of the motor shaft system in the compressor exceeds 85 DEG C, opening a needle valve to guide part of the high-pressure natural gas with the temperature of 50 + / -2 DEG C output by the air-cooled heat exchanger into the motor shaft system in the compressor, so that the temperature of the motor shaft system in the compressor is stabilized at 65 + / -2 DEG C; and starting the air-cooled water chiller to input cooling water at the lowest temperature of 8 DEG C to the compressor shell and the frequency converter water cooling plate abutting against the frequency converter, so that the temperature of the compressor shell is not higher than 45 DEG C, and the temperature of the frequency converter body is not higher than 50 DEG C. The method has the advantage that all parts of the compressor and the frequency converter are efficiently cooled.

Description

Technical Field

[0001] This invention relates to the field of compressor cooling technology, and in particular to a composite cooling method for booster equipment, booster medium and its control system. Background Technology

[0002] During the natural gas compression and transportation process, the natural gas compressor, as the core booster equipment, generates a significant amount of heat during operation. Simultaneously, the compressed booster medium and related control systems also experience temperature increases. Failure to effectively cool these heat-generating components can not only affect the equipment's normal operating efficiency but may also lead to overheating damage and even safety hazards.

[0003] Traditional cooling methods often suffer from insufficient targeting, poor cooling effect, or inability to meet special environmental requirements (such as explosion-proof requirements). For example, for compressor motor frequency converters installed in explosion-proof control cabinets, direct connection to a water source for cooling does not comply with explosion-proof specifications and is difficult to achieve safe and effective cooling; and a single cooling method is also difficult to simultaneously meet the cooling needs of different components and pressurizing media in booster equipment.

[0004] Therefore, to address the above shortcomings, a combined cooling method for the booster equipment, the booster medium, and its control system is needed. Summary of the Invention

[0005] (a) Technical problems to be solved The technical problem to be solved by the present invention is to address the shortcomings and poor cooling effect of existing cooling methods in the cooling process of natural gas compressors and their related components and media.

[0006] (II) Technical Solution To address the aforementioned technical problems, this invention provides a composite cooling method for booster equipment, booster medium, and their control system, comprising the following steps: Ⅰ. Start the compressor to pressurize the natural gas in the low temperature and low pressure zone to the high temperature and high pressure zone, and start the air-cooled heat exchanger to reduce the high temperature and high pressure natural gas output by the compressor to high pressure natural gas of 50℃±2℃; Ⅱ. When the temperature of the motor shaft system inside the compressor exceeds 85℃, open the needle valve to introduce part of the high-pressure natural gas at 50℃±2℃ output from the air-cooled heat exchanger into the motor shaft system inside the compressor, so that the temperature of the motor shaft system inside the compressor (1) is stabilized at 65℃±2℃. III. Start the air-cooled chiller to supply cooling water at a minimum temperature of 8°C to the compressor casing and the inverter water-cooling plate that contacts the inverter, so that the compressor casing temperature does not exceed 45°C and the inverter body temperature does not exceed 50°C.

[0007] As a further explanation of the present invention, preferably, PT100 / K type thermocouples are installed at the compressor outlet, the compressor motor shaft, the compressor housing, and the surface of the frequency converter. The thermocouples are electrically connected to the control system, and the control system is electrically connected to each valve on the pipeline.

[0008] As a further explanation of the present invention, preferably, the natural gas pressure output by the compressor is 5 to 15 MPa, and the output temperature is between 120°C and 160°C.

[0009] As a further explanation of the present invention, preferably, the cooling air volume of the air-cooled heat exchanger satisfies the following: in, For a moment Air volume at that time; The reference air volume; The dimension conversion coefficient; For compressor 1 at time The outlet temperature at that time; The target cooling temperature for the air-cooled heat exchanger is 50℃±2℃.

[0010] As a further explanation of the present invention, preferably, the airflow regulated by the needle valve satisfies the following: in, For needle valve at time The airflow to the motor shaft system is controlled in real time; This is the reference airflow for the needle valve; The dimension conversion coefficient; For the motor shaft system at time The temperature at that time; This is the target cooling temperature for the motor shaft system.

[0011] As a further explanation of the present invention, preferably, the cooling water flow rate diverted to the compressor housing is... satisfy: in, This is the reference value for the cooling water flow rate diverted to the compressor housing; The dimension conversion coefficient; For the compressor housing in time Temperature deviation within; The dimension conversion coefficient; Represented as arrive The cumulative sum of the temperature deviation of the compressor casing over time within the cycle.

[0012] As a further explanation of the present invention, preferably, the cooling water flow rate diverted to the inverter water-cooled plate is... satisfy: in, This is the reference value for the cooling water flow rate diverted to the water-cooled plate of the frequency converter; The dimension conversion coefficient; For the water-cooled plate of the frequency converter in time Temperature deviation within; The dimension conversion coefficient; Represented as arrive The sum of the frequency converter temperature deviation accumulated over time within the cycle.

[0013] As a further explanation of the present invention, preferably, the air-cooled chiller is used in time... water outlet temperature at that time satisfy: in, Current time The temperature of the water returning to the air-cooled chiller; This is the difference between the outlet water temperature and the return water temperature.

[0014] As a further explanation of the present invention, preferably, the difference between the outlet water temperature and the return water temperature is... satisfy: in, The heat transfer coefficient between the compressor casing and the cooling water; The heat transfer coefficient between the inverter's water-cooled plate and the cooling water; The specific heat capacity of water is taken as 4.2 kJ / (kg·K); The density of water is taken as 1000 kg / m³. 3 ; The total cooling water flow rate, i.e. .

[0015] As a further explanation of the present invention, preferably, the inverter water-cooling plate has a plate-like structure and a built-in microchannel copper alloy plate with a channel diameter of 3-5 mm; the outer wall thickness of the inverter water-cooling plate is 3-3.5 mm to improve the explosion-proof rating to Ex dIIC T6.

[0016] (III) Beneficial Effects The above-described technical solution of the present invention has the following advantages: 1. For different parts that require cooling, different cooling methods are used, such as air-cooled heat exchangers, high-pressure air sources after cooling, and air-cooled water chillers, to ensure that each part can receive appropriate cooling treatment.

[0017] 2. By selecting appropriate cooling methods and designing process flows, the temperature of each cooling component can be effectively reduced, such as lowering the temperature of the compressed pipeline gas to below 50℃; ensuring that the equipment and media are within a suitable operating temperature range, and improving equipment operating efficiency.

[0018] 3. The cooling of the booster equipment, booster medium and its control system is integrated into a composite cooling system, with each cooling component working together to improve overall cooling efficiency and stability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the pipeline structure of the present invention.

[0020] In the diagram: 1. Compressor; 2. Air-cooled heat exchanger; 21. Needle valve; 3. Air-cooled chiller; 4. Inverter water-cooled plate. Detailed Implementation

[0021] 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.

[0022] A composite cooling method for booster equipment, booster medium, and its control system, such as... Figure 1 As shown, it includes the following steps: I. Open the valve at the front end of the filter to introduce natural gas into the filter. After filtration, the dust content will be ≤5mg / m³. 3 The method applies to three types of compressors 1: small-to-medium, medium-sized, and large-sized. The inlet pressure of each compressor 1 ranges from 6 to 1.0 MPa, the inlet temperature from 23 to 26°C, and the impeller speed from 25,000 to 30,000 r / min. The outlet pressure of the compressor 1 ranges from 5 to 15 MPa, and the outlet temperature from 120 to 160°C. PT100 / K type thermocouples are installed at the outlet of compressor 1, the motor shaft of compressor 1, the casing of compressor 1, and the surface of the frequency converter for accurate temperature measurement. The thermocouples are electrically connected to the control system, which in turn is electrically connected to various valves on the pipeline for regulating their opening and closing to control the flow rate of cooling gas and cooling water.

[0023] II. Start the air-cooled heat exchanger 2, with the initial airflow set to the preset baseline value. For the small to medium-sized compressor 1, the initial airflow is set to 12000 m³ / h. 3 / h; For medium-sized compressor 1, the initial air volume is set to 18000m³ / h. 3 / h; For large compressor 1, the initial air volume is set to 28000m³ / h. 3 / h. Based on the above benchmark value, the pressurized high-temperature natural gas is cooled down.

[0024] Temperature is collected in real time by a PT100 / K type sensor at the gas outlet of the pipeline, with a sampling period of 1 second. The specific cooling airflow of the air-cooled heat exchanger 2 is as follows: in, For a moment Air volume at that time; The reference air volume; For the dimension conversion factor, the factor is 400 for small and medium compressor 1, 600 for medium compressor 1, and 800 for large compressor 1; For compressor 1 at time The outlet temperature at that time; The target temperature is to be cooled by the air-cooled heat exchanger 2.

[0025] The temperature of the compressed gas in the pipeline needs to be kept stable within 50℃±2℃ and maintained for 30 seconds without overheating.

[0026] III. The cooled pipeline gas begins to be diverted as the cooling gas source for the motor shaft system. The initial gas flow rate is controlled by needle valve 21, with the initial gas flow rate being 190 Nm³ / h for small and medium-sized compressor 1, 313 Nm³ / h for medium-sized compressor 1, and 480 Nm³ / h for large compressor 1. Real-time temperature is collected by a type K thermocouple on the motor shaft system, and the opening of needle valve 21 is adjusted to control the cooling gas flow rate, specifically: in, For needle valve 21 at time The airflow to the motor shaft system is controlled in real time; The reference airflow for needle valve 21; For the dimension conversion factor, the factor is 15 for small and medium compressor 1, 20 for medium compressor 1, and 25 for large compressor 1; For the motor shaft system at time The temperature at that time; This is the target cooling temperature for the motor shaft system.

[0027] The cooled natural gas flows back into the pipeline in the low-pressure zone, where it re-enters the compressor 1 for secondary pressurization, thus achieving recirculation and reuse.

[0028] IV. Start the air-cooled chiller 3 and output cooling water according to the preset reference parameters. The preset outlet water temperature reference value is 12℃ for small and medium-sized compressor 1, 10℃ for medium-sized compressor 1, and 8℃ for large compressor 1. The initial water flow rate to the casing operates according to the reference value, with the preset flow rate reference value for small and medium-sized compressor 1 being 2.3m³ / h. 3 / h, the set flow rate benchmark value for medium-sized compressor 1 is 3.74m³ / h. 3 / h, the set flow rate benchmark value for large compressor 1 is 6.1m³ / h. 3 / h. The real-time temperature is collected by a PT100 sensor on the surface of compressor 1 housing, and the cooling water flow rate diverted to the compressor 1 housing is then calculated. for: in, The reference value for the flow rate of cooling water diverted to the casing of compressor 1; The dimension conversion coefficient; For the compressor 1 casing in time Temperature deviation within; The dimension conversion coefficient; Represented as arrive The cumulative sum of the temperature deviation of the compressor 1 casing over time during the cycle.

[0029] Simultaneously, cooling water is diverted from the chiller's main water circuit to the inverter water-cooled plate 4. The inverter water-cooled plate 4 has a plate-like structure and incorporates a microchannel copper alloy plate with a channel diameter of 3–5 mm; the outer wall thickness of the inverter water-cooled plate 4 is 3–3.5 mm to upgrade the explosion-proof rating to Ex d IIC T6. The initial water flow rate diverted to the inverter water-cooled plate 4 operates according to a preset baseline value, with an initial water flow rate of 0.65 m³ / h for the small and medium-sized compressor 1. 3 The initial water flow rate of medium-sized compressor 1 is 1.07 m³ / h. 3 The initial water flow rate of large compressor 1 is 1.7 m³ / h. 3 / h. Ensure there are no leaks at the inlet and outlet water ports of the inverter water-cooled plate 4, which is located outside the explosion-proof cabinet. Real-time temperature is collected by the inverter's own sensors; adjusting the opening of the electric regulating valve for the cooling water of the inverter water-cooled plate 4 then adjusts the flow rate of cooling water diverted to the inverter water-cooled plate 4. satisfy: in, This is the reference value for the cooling water flow rate diverted to the water-cooled plate of the frequency converter; The dimension conversion coefficient; For the water-cooled plate of the frequency converter in time Temperature deviation within; The dimension conversion coefficient; Represented as arrive The sum of the frequency converter temperature deviation accumulated over time within the cycle.

[0030] V. After cooling, to further save energy, the outlet water temperature of the air-cooled chiller 4 also needs to be adjusted; it is not advisable to always use the reference value. The air-cooled chiller 4... water outlet temperature at that time satisfy: in, Current time The temperature of the water returning to the air-cooled chiller; The difference between the outlet water temperature and the return water temperature is as follows: in, The heat transfer coefficient between the compressor casing and the cooling water; The heat transfer coefficient between the inverter's water-cooled plate and the cooling water; The specific heat capacity of water is taken as 4.2 kJ / (kg·K); The density of water is taken as 1000 kg / m³. 3 ; The total cooling water flow rate, i.e. .

[0031] Unlike traditional cooling solutions that use a uniform airflow or water flow rate to cool compressors of different specifications, leading to energy waste in small and medium-sized compressors ("overpowered engines for small loads") or insufficient cooling in large compressors ("underpowered engines for large loads"), this invention uses preset parameter ranges to match the compressor model, ensuring that the initial cooling parameters of three types of compressors are precisely adapted to their rated loads. This is the first time a single method has been used to cover multiple specifications without waste. Furthermore, it uses cooled high-pressure natural gas circulation to cool the motor shaft system. Firstly, the density of high-pressure gas is 95 times that of room-temperature air, increasing heat exchange efficiency by more than 100 times. Secondly, the high-temperature, high-pressure gas after cooling the shaft system is returned to preheat the original intake air. Although the intake air temperature increases, the high-pressure gas reduces throttling losses, resulting in a 2.8%–3.2% reduction in compression power. Thirdly, it solves the problem that water cooling cannot directly contact the motor shaft system, and air cooling avoids oxidation damage to the motor shaft, resulting in higher direct contact cooling efficiency.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite cooling method for booster equipment, booster medium, and their control system, characterized in that: Includes the following steps: Ⅰ. Start the compressor (1) to pressurize the natural gas in the low temperature and low pressure zone to the high temperature and high pressure zone, and start the air-cooled heat exchanger (2) to reduce the high temperature and high pressure natural gas output by the compressor (1) to high pressure natural gas of 50℃±2℃; Ⅱ. When the temperature of the motor shaft system inside the compressor (1) exceeds 85℃, open the needle valve (21) to introduce part of the high-pressure natural gas at 50℃±2℃ output from the air-cooled heat exchanger (2) into the motor shaft system inside the compressor (1) so that the temperature of the motor shaft system inside the compressor (1) is stabilized at 65℃±2℃. III. Start the air-cooled chiller (3) to input cooling water at a minimum temperature of 8°C into the casing of the compressor (1) and the water-cooled plate (4) of the inverter that abuts against the inverter, so that the temperature of the casing of the compressor (1) is not higher than 45°C and the temperature of the inverter body is not higher than 50°C.

2. The composite cooling method for a booster device, a booster medium, and its control system according to claim 1, characterized in that: PT100 / K type thermocouples are installed on the compressor (1) outlet, compressor (1) motor shaft, compressor (1) housing and inverter surface. The thermocouples are electrically connected to the control system, and the control system is electrically connected to each valve on the pipeline.

3. The composite cooling method for the booster equipment, the booster medium, and its control system according to claim 2, characterized in that: The compressor (1) outputs natural gas at a pressure of 5-15 MPa and an output temperature of 120℃-160℃.

4. The composite cooling method for the booster equipment, the booster medium, and its control system according to claim 3, characterized in that: The cooling air volume of the air-cooled heat exchanger (2) meets the following requirements: in, For a moment Air volume at that time; The reference air volume; The dimension conversion coefficient; For compressor 1 at time The outlet temperature at that time; The target temperature for the air-cooled heat exchanger (2) is 50℃±2℃.

5. A composite cooling method for a booster device, a booster medium, and its control system according to claim 3, characterized in that: The airflow regulated by the needle valve (21) satisfies: in, For the needle valve (21) at time The airflow to the motor shaft system is controlled in real time; The reference airflow for the needle valve (21); The dimension conversion coefficient; For the motor shaft system at time The temperature at that time; This is the target cooling temperature for the motor shaft system.

6. The composite cooling method for booster equipment, booster medium and its control system according to claim 1, characterized in that: Cooling water flow rate diverted to the compressor (1) casing satisfy: in, The reference value for the flow rate of cooling water diverted to the casing of compressor (1); The dimension conversion coefficient; For the compressor (1) casing in time Temperature deviation within; The dimension conversion coefficient; Represented as arrive The cumulative sum of the temperature deviation of the compressor (1) casing over time during the cycle.

7. A composite cooling method for a booster device, a booster medium, and its control system according to claim 6, characterized in that: Cooling water flow rate diverted to the inverter water-cooled plate (4) satisfy: in, The reference value for the cooling water flow rate diverted to the inverter water-cooled plate (4); The dimension conversion coefficient; For the inverter water cooling plate (4) in time Temperature deviation within; The dimension conversion coefficient; Represented as arrive The sum of the frequency converter temperature deviation accumulated over time within the cycle.

8. A composite cooling method for a booster device, a booster medium, and its control system according to claim 7, characterized in that: Air-cooled chiller (3) in time water temperature at time satisfy: in, Current time The water temperature returned to the air-cooled chiller (3); This is the difference between the outlet water temperature and the return water temperature.

9. A composite cooling method for a booster device, a booster medium, and its control system according to claim 8, characterized in that: The difference between the outlet water temperature and the return water temperature satisfy: in, The heat transfer coefficient between the compressor (1) casing and the cooling water; The heat transfer coefficient between the inverter water-cooled plate (4) and the cooling water; The specific heat capacity of water is taken as 4.2 kJ / (kg·K); The density of water is taken as 1000 kg / m³. 3 ; The total cooling water flow rate, i.e. .

10. A composite cooling method for a booster device, a booster medium, and its control system according to claim 9, characterized in that: The inverter water-cooled plate (4) has a plate-shaped structure and a built-in microchannel copper alloy plate with a channel diameter of 3-5mm; the outer wall thickness of the inverter water-cooled plate (4) is 3-3.5mm to improve the explosion-proof rating to Ex d IIC T6.

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