Automatic humidification system for centrifugal compressor

Abstract

The application discloses a centrifugal compressor automatic humidification system, comprising: a constant temperature water tank, arranged at a high position, forming a height difference with a compressor impeller to provide a pressurized water source, and a water tank water discharge valve is installed at the bottom of the constant temperature water tank; an automatic water replenishment pump connected to the constant temperature water tank for maintaining constant water level in the water tank; a water tank heater arranged in the constant temperature water tank for adjusting the water temperature to the target range ±10℃. The centrifugal compressor automatic humidification system can determine the optimal pressure setting value through system debugging, so that the humidification flow and the compressor operation condition are dynamically matched, and the system structure is simplified compared with the traditional PID control. By using a self-powered pressure regulating valve, the humidification flow is controlled by a pure mechanical structure, and the system is simple and reliable. A water collecting chamber is arranged in front of the atomizing nozzle to ensure the stability of the pressure in front of the atomizing nozzle, and the pressure tapping port of the self-powered pressure regulating valve is arranged in the water collecting chamber, so that the influence of flow rate fluctuation on pressure regulation is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat pumps, in particular to an automatic humidification system for centrifugal compressors. BACKGROUND

[0002] Centrifugal compressors are one of the power machines in the industrial field, and are widely used in refrigeration, energy storage, heat pumps and other fields, mainly for air compression, water vapor compression and compression of other working fluids. When cooling is not used, heat cannot be dissipated in time, so this process is close to an isentropic process. As the pressure increases, the temperature of the working fluid also increases, which also increases the power consumption. For the same compression process, the power consumption of isothermal compression is the lowest, so reducing the exhaust temperature is an effective way to improve the compression efficiency and reduce the compression power consumption. On the other hand, the reduction of exhaust temperature is beneficial to the mechanical strength of the impeller and the lubrication of the bearing. Especially in the field of heat pumps, the industry is committed to developing high-temperature heat pumps with exhaust temperatures above 100℃. In order to solve the problem of excessive exhaust temperature, it is necessary to cool the compression process.

[0003] The current humidification method is usually inlet humidification and inter-stage humidification of the compressor. The humidification process usually uses manual valve control or closed-loop control with a controller. With the development of technology, various humidification methods such as wheel cover humidification and flow channel humidification have gradually appeared, making humidification and cooling more precise, and the corresponding humidification process needs to be adjusted and optimized. SUMMARY

[0004] The purpose of the present application is to provide an automatic humidification system for centrifugal compressors to solve the problem of the humidification process usually using manual valve control or closed-loop control with a controller as described in the background.

[0005] To achieve the above purpose, the present application provides the following technical scheme: an automatic humidification system for centrifugal compressors, comprising:

[0006] A constant-temperature water tank is arranged at a high position and forms a height difference with the compressor impeller to provide a pressurized water source, and a water tank drain valve is installed at the bottom of the constant-temperature water tank;

[0007] An automatic water replenishment pump is connected to the constant-temperature water tank for maintaining a constant water level in the tank;

[0008] A water tank heater is provided in the constant-temperature water tank for adjusting the water temperature to a target range of ±10℃;

[0009] A low-pressure humidification pipeline includes a front manual valve of a self-operated regulating valve, a low-pressure humidification pipeline self-operated pressure regulating valve, a rear manual valve of the regulating valve, a check valve, a trap valve, a low-pressure humidification pipeline water collecting chamber and an atomizing hole connected in sequence;

[0010] The high-pressure humidification pipeline comprises, in sequence, a manual valve before a self-operated regulating valve, a self-operated pressure regulating valve of the high-pressure humidification pipeline, a manual valve after the regulating valve, a check valve, a drain valve, a water collecting chamber of the high-pressure humidification pipeline, and an atomizing hole.

[0011] The pressure signal acquisition unit comprises a pressure tapping pipe of the self-operated pressure regulating valve of the low-pressure humidification pipeline and a pressure tapping pipe of the self-operated pressure regulating valve of the high-pressure humidification pipeline, which respectively acquire static pressure signals from the water collecting chamber of the low-pressure humidification pipeline and the water collecting chamber of the high-pressure humidification pipeline and feed back the static pressure signals to the self-operated pressure regulating valve of the low-pressure humidification pipeline and the self-operated pressure regulating valve of the high-pressure humidification pipeline.

[0012] The compressor impeller is provided with the low-pressure humidification atomizing hole and the high-pressure humidification atomizing hole in a flow channel thereof.

[0013] The compressor outlet thermocouple is used for monitoring an outlet working medium temperature and assisting in judging a running state of the humidification system.

[0014] Preferably, the self-operated pressure regulating valve of the low-pressure humidification pipeline and the self-operated pressure regulating valve of the high-pressure humidification pipeline are of a valve-after-pressure-regulating type, and target pressure values (P21, P22) thereof are determined through debugging.

[0015] An initial set value is a theoretical pressure (P21, P22) calculated according to a flow of the atomizing nozzle;

[0016] An actual flow of the atomizing nozzle is adjusted to reach an optimal value, and a corresponding pressure value is a final set value (P21, P22) at this time.

[0017] Preferably, the water collecting chamber of the low-pressure humidification pipeline and the water collecting chamber of the high-pressure humidification pipeline are annular cavities, the water collecting chamber (11) of the low-pressure humidification pipeline is integrated at an inlet rotor end portion of the flow channel, and low-pressure humidification atomizing holes are arranged on a circumferential wall surface of the rotor for uniformly spraying water mist to the flow channel; the water collecting chamber (20) of the high-pressure humidification pipeline is integrated on an outer side of a compressor wheel cover, and high-pressure humidification atomizing holes (25) are arranged on the wheel cover for uniformly spraying water mist to the flow channel.

[0018] Preferably, the bypass valves of the self-operated regulating valves of the low-pressure humidification pipeline and the high-pressure humidification pipeline are used for switching to bypass operation when the self-operated regulating valves fail.

[0019] Preferably, a height difference of the constant-temperature water tank is designed to meet an inlet pressure requirement of the self-operated regulating valve, and a water level fluctuation range is controlled within a design range by an automatic water supplement pump.

[0020] Preferably, the check valves of the low-pressure humidification pipeline and the high-pressure humidification pipeline are used for preventing working medium from flowing back to a water supply pipeline when pressure of the water collecting chamber of the low-pressure humidification pipeline and the water collecting chamber of the high-pressure humidification pipeline abnormally rises.

[0021] Preferably, the low-pressure humidification pipeline trap and the high-pressure humidification pipeline trap are opened to drain pipeline water during system maintenance and are closed during normal operation.

[0022] Compared with the prior art, the centrifugal compressor automatic humidification system has the following beneficial effects:

[0023] The centrifugal compressor automatic humidification system adopts a self-operated pressure regulating valve to realize pure mechanical closed-loop control, obtains a stable static pressure signal through a water collecting chamber, avoids the interference of pipeline flow rate fluctuation on pressure regulation, and ensures the precise and constant pressure before the atomizing nozzle. The best pressure set value can be determined through system debugging, so that the humidification flow rate is dynamically matched with the compressor operation condition, and the system structure is simplified compared with traditional PID control. The self-operated pressure regulating valve is used to control the humidification flow rate in a pure mechanical mode, and the system is simple and reliable. The water collecting chamber is arranged before the atomizing nozzle to ensure the stability of the pressure before the atomizing nozzle, and the pressure tapping port of the self-operated pressure regulating valve is arranged in the water collecting chamber, so that the pressure regulation is not affected by the flow rate fluctuation. BRIEF DESCRIPTION OF DRAWINGS

[0024] Fig. 1 It is a centrifugal compressor wet compression process diagram of the present application;

[0025] Fig. 2 It is a centrifugal compressor wheel cover structure schematic diagram of the present application.

[0026] In the figure: 1, constant temperature water tank; 2, water tank heater; 3, water tank drain valve; 4, automatic water replenishing pump; 5, low-pressure humidification pipeline self-operated regulating valve front manual valve; 6, low-pressure humidification pipeline self-operated pressure regulating valve; 7, low-pressure humidification pipeline self-operated regulating valve rear manual valve; 8, low-pressure humidification pipeline check valve; 9, low-pressure humidification pipeline self-operated regulating valve bypass valve; 10, low-pressure humidification pipeline trap; 11, low-pressure humidification pipeline water collecting chamber; 12, low-pressure humidification pipeline; 13, low-pressure humidification pipeline self-operated pressure regulating valve pressure tapping pipe; 14, high-pressure humidification pipeline self-operated regulating valve front manual valve; 15, high-pressure humidification pipeline self-operated pressure regulating valve; 16, high-pressure humidification pipeline self-operated regulating valve rear manual valve; 17, high-pressure humidification pipeline check valve; 18, high-pressure humidification pipeline self-operated regulating valve bypass valve; 19, high-pressure humidification pipeline trap; 20, high-pressure humidification pipeline water collecting chamber; 21, high-pressure humidification pipeline; 22, high-pressure humidification pipeline self-operated pressure regulating valve pressure tapping pipe; 23, compressor impeller; 24, low-pressure humidification atomizing hole; 25, high-pressure humidification atomizing hole; 26, compressor outlet thermocouple. DETAILED DESCRIPTION

[0027] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0028] Please refer to Figs. 1-2 The present application provides a technical solution: an automatic humidification system of a centrifugal compressor, comprising:

[0029] The constant-temperature water tank 1 is arranged at a high position and forms a height difference with the compressor impeller 23 to provide a pressurized water source. The specific height difference is determined according to the type of the self-operated regulating valve to ensure that the inlet pressure requirement of the self-operated regulating valve is met. The water level fluctuation range of the constant-temperature water tank 1 is controlled within the design range by the automatic water replenishing pump 4, and the constant-temperature water tank 1 is provided with a water tank drain valve 3 at the bottom. The normal working position of the water tank drain valve 3 is the closed position, and the valve is opened when it is necessary to drain the water tank. Usually, the valve is used when the system is overhauled or the water tank is cleaned.

[0030] The automatic water replenishing pump 4 is connected to the constant-temperature water tank 1 and is used to maintain the water level of the water tank constant. By automatic water replenishing, the water level of the water tank is ensured to be within the design range, so that the water level difference is fixed and the pressure before the self-operated regulating valve is constant at P1.

[0031] The water tank heater 2 is arranged in the constant-temperature water tank 1 and automatically adjusts according to the detected water tank temperature. According to the simulation results of CFD, the temperature of the liquid droplets has very little effect on humidification, so the temperature control of the water tank does not need to be very accurate. There is no obvious influence on the humidification effect within ±10℃ of the target water level range.

[0032] The low-pressure humidification pipeline 12 comprises, in sequence, a low-pressure humidification pipeline self-operated regulating valve front manual valve 5, a low-pressure humidification pipeline self-operated pressure regulating valve 6, a low-pressure humidification pipeline self-operated regulating valve rear manual valve 7, a low-pressure humidification pipeline check valve 8, a low-pressure humidification pipeline trap valve 10, a low-pressure humidification pipeline water collecting chamber 11, and a low-pressure humidification atomizing hole 24. The low-pressure humidification pipeline water collecting chamber 11 and the high-pressure humidification pipeline water collecting chamber 20 are arranged in front of the atomizing nozzle and are cavities for storing liquid water. The cavities are connected with the water supply pipeline and simultaneously provide the pressure signal for the self-operated regulating valve. The static pressure signal obtained in the chamber is more accurate and stable than the pressure obtained at the opening of the pipeline, and is not easily affected by the flow rate.

[0033] High-pressure humidification pipeline 21, including the low-pressure humidification pipeline self-regulating valve before the front manual valve 14, high-pressure humidification pipeline self-regulating valve before the front manual valve 15, high-pressure humidification pipeline self-regulating valve after the front manual valve 16, high-pressure humidification pipeline check valve 17, high-pressure humidification pipeline drain valve 19, high-pressure humidification pipeline water collecting chamber 20 and high-pressure humidification atomizing hole 25 are connected in sequence;

[0034] The low-pressure humidification pipeline self-regulating valve before the front manual valve 5 and the high-pressure humidification pipeline self-regulating valve before the front manual valve 14 and the low-pressure humidification pipeline self-regulating valve after the front manual valve 7 and the high-pressure humidification pipeline self-regulating valve after the front manual valve 16 are arranged before and after the self-regulating valve, the valve has the function of cutting off the working medium, also has the function of isolating the self-regulating valve, and the normal valve position is the open position.

[0035] The pressure signal acquisition unit includes the low-pressure humidification pipeline self-regulating pressure valve pressure taking pipe 13 and the high-pressure humidification pipeline self-regulating pressure valve pressure taking pipe 22, which respectively collect the static pressure signals from the low-pressure humidification pipeline water collecting chamber 11 and the high-pressure humidification pipeline water collecting chamber 20 and feed back to the low-pressure humidification pipeline self-regulating pressure valve 6 and the high-pressure humidification pipeline self-regulating pressure valve 15, the low-pressure humidification pipeline self-regulating pressure valve 6 and the high-pressure humidification pipeline self-regulating pressure valve 15 are the valve after pressure regulating type, the target pressure values P21, P22 are determined through debugging, specifically, the initial set value is the theoretical pressure P21, P22 calculated according to the atomizing nozzle flow; the actual flow of the atomizing nozzle is adjusted to reach the best value, at this time, the corresponding pressure value is the final set value P21, P22, the low-pressure humidification pipeline water collecting chamber 11 and the high-pressure humidification pipeline water collecting chamber 20 are annular cavities integrated in the compressor wheel cover;

[0036] The low-pressure humidification pipeline and the high-pressure humidification pipeline are respectively provided with the low-pressure humidification pipeline self-regulating valve bypass valve 9 and the high-pressure humidification pipeline self-regulating valve bypass valve 18, which are used for switching to bypass operation when the self-regulating valve fails;

[0037] The low-pressure humidification pipeline self-regulating valve bypass valve 9 and the high-pressure humidification pipeline self-regulating valve bypass valve 18 are used for bypassing the self-regulating valve, and the normal state is the closed position. When the self-regulating valve is stuck or fails in use, the valve is opened, the manual valves before and after the self-regulating valve are closed, and the bypass short-time operation is put into use. After the self-regulating valve failure is eliminated, the valve is closed.

[0038] The compressor impeller 23 is provided with the low-pressure humidification atomizing hole 24 and the high-pressure humidification atomizing hole 25 in the flow channel; the low-pressure humidification pipeline check valve 8 and the high-pressure humidification pipeline check valve 17 are used for preventing the working medium from flowing back to the water supply pipeline when the pressure of the low-pressure humidification pipeline water collecting chamber 11 and the high-pressure humidification pipeline check valve 17 abnormally rises;

[0039] The water in the low-pressure humidification pipeline water collecting chamber 11 is sprayed into the flow channel from the low-pressure humidification atomizing holes 24, which can be arranged in multiple places in the circumferential direction; the water in the high-pressure humidification pipeline water collecting chamber 20 is sprayed into the flow channel from the high-pressure humidification atomizing holes 25, which can be arranged in multiple places in the circumferential direction; the water collecting chamber is annular and integrated with the wheel cover, and is used for uniformly spraying water mist to the flow channel.

[0040] The compressor outlet thermocouple 26 is used for monitoring the outlet working medium temperature, and plays an auxiliary monitoring role for the running state of the humidification system; when the temperature deviates from the outlet temperature in the normal working state, it is necessary to check whether the humidification system has a fault.

[0041] The low-pressure humidification pipeline drain valve 10 and the high-pressure humidification pipeline drain valve 19 are opened to drain the pipeline accumulated water during system maintenance, and are in a closed state during normal operation.

[0042] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An automatic humidification system for a centrifugal compressor, characterized in that, include: The constant temperature water tank (1) is located at a high position, forming a height difference with the compressor impeller (23) to provide a pressurized water source, and a water tank drain valve (3) is installed at the bottom of the constant temperature water tank (1). An automatic water replenishment pump (4) is connected to a constant temperature water tank (1) to maintain a constant water level in the tank; A water tank heater (2) is installed in a constant temperature water tank (1) to adjust the water temperature to the target range of ±10℃; The low-pressure humidification pipeline (12) includes a manual valve (5) before the low-pressure humidification pipeline self-regulating valve, a low-pressure humidification pipeline self-regulating pressure regulating valve (6), a manual valve (7) after the low-pressure humidification pipeline self-regulating valve, a low-pressure humidification pipeline check valve (8), a low-pressure humidification pipeline drain valve (10), a low-pressure humidification pipeline water collection chamber (11), and a low-pressure humidification atomizing hole (24) connected in sequence. The high-pressure humidification pipeline (21) includes a manual valve (14) before the high-pressure humidification pipeline self-regulating valve, a high-pressure humidification pipeline self-regulating pressure regulating valve (15), a manual valve (16) after the high-pressure humidification pipeline self-regulating valve, a high-pressure humidification pipeline check valve (17), a high-pressure humidification pipeline self-regulating valve bypass valve (18), a high-pressure humidification pipeline drain valve (19), a high-pressure humidification pipeline water collection chamber (20), and a high-pressure humidification atomizing hole (25) connected in sequence. The pressure signal acquisition unit includes a pressure tapping pipe (13) for the self-regulating pressure valve of the low-pressure humidification pipeline and a pressure tapping pipe (22) for the self-regulating pressure valve of the high-pressure humidification pipeline. The static pressure signals are collected from the water collection chamber (11) of the low-pressure humidification pipeline and the water collection chamber (20) of the high-pressure humidification pipeline and fed back to the self-regulating pressure regulating valve (6) of the low-pressure humidification pipeline and the self-regulating pressure regulating valve (15) of the high-pressure humidification pipeline, respectively. The compressor impeller (23) has low-pressure humidification atomizing holes (24) and high-pressure humidification atomizing holes (25) arranged in its flow channel; The compressor outlet thermocouple (26) is used to monitor the outlet working fluid temperature and assist in judging the operating status of the humidification system; The low-pressure humidification pipeline water collection chamber (11) and the high-pressure humidification pipeline water collection chamber (20) are annular cavities. The low-pressure humidification pipeline water collection chamber (11) is integrated at the rotor inlet end of the flow channel. Low-pressure humidification atomizing holes are arranged circumferentially on the inner wall of the rotor for uniformly spraying water mist into the flow channel. The high-pressure humidification pipeline water collection chamber (20) is integrated on the outer side of the compressor wheel cover. High-pressure humidification atomizing holes (25) are arranged circumferentially at the wheel cover for uniformly spraying water mist into the flow channel.

2. The automatic humidification system for a centrifugal compressor according to claim 1, characterized in that, The self-regulating pressure regulating valve (6) for the low-pressure humidification pipeline and the self-regulating pressure regulating valve (15) for the high-pressure humidification pipeline are downstream pressure regulating types. Their target pressure values ​​are determined through debugging, specifically: The initial setting is the theoretical pressure calculated based on the atomizing nozzle flow rate; By adjusting the nozzle to achieve the optimal actual flow rate, the corresponding pressure value is the final set value.

3. The system according to claim 1, characterized in that, The height difference design of the constant temperature water tank (1) meets the inlet pressure requirements of the self-regulating valve, and its water level fluctuation range is controlled within the design range by the automatic water replenishment pump (4).

4. The system according to claim 1, characterized in that, The low-pressure humidification pipeline check valve (8) and the high-pressure humidification pipeline check valve (17) are used to prevent the working fluid from flowing back into the water supply pipeline when the pressure in the low-pressure humidification pipeline water collection chamber (11) and the high-pressure humidification pipeline water collection chamber (20) rises abnormally.

5. The system according to claim 1, characterized in that, The low-pressure humidification pipeline drain valve (10) and the high-pressure humidification pipeline drain valve (19) are opened during system maintenance to drain accumulated water in the pipeline, and are closed during normal operation.

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