A closed condensate tank system and a closed condensate water recovery system

Abstract

The application discloses a closed condensate tank system, comprising: a condensate tank with a condensate water inlet, a flash steam outlet and a pressure sensor for detecting the pressure in the condensate tank; a steam ejector with a first steam inlet communicating with a main steam inlet pipeline, a second steam inlet communicating with the flash steam outlet and a steam outlet communicating with a steam-using device; a proportional regulating valve connected in series on the main steam inlet pipeline; and a controller for reducing the opening of the proportional regulating valve when the pressure in the condensate tank exceeds the upper limit of a pressure threshold range, and increasing the opening of the proportional regulating valve when the pressure in the condensate tank is lower than the lower limit of the pressure threshold range, wherein the upper limit of the pressure threshold range is less than the atmospheric pressure. The application stabilizes the working condition of the steam-using device by setting a unified and stable back pressure of the return water, and avoids the working disorder of the steam-using device, or even the non-working condition. The application further discloses a closed condensate water recovery system.

Description

Technical Field

[0001] The present invention relates to the technical field of condensate recovery, and in particular to a closed condensate tank system and a closed condensate recovery system. Background Art

[0002] Today, as energy consumption increases rapidly, the ever-improving material and cultural life of mankind places an increasing demand on energy. As a technology that can produce greater effects through a certain amount of energy input, energy-saving technology has been increasingly widely used.

[0003] Condensate recovery technology, as a key energy-saving and consumption-reducing measure, has attracted significant attention from domestic and international companies. After steam releases latent heat and condenses in steam-using equipment, the condensate is discharged through a steam trap and recycled through a recovery network into a condensate tank, ultimately returning it to the boiler or other heat-using equipment. Condensate recovery systems recycle the heat (including flash steam heat) from the condensate and are generally classified as either open or closed systems.

[0004] (1) Open system

[0005] The system's condensate collection tank is open and vented to the atmosphere. As the condensate enters the tank, its pressure suddenly drops, and the water temperature rises above its boiling point, generating a large amount of secondary flash steam. The condensate temperature after flashing is approximately 100°C. However, due to prolonged storage and the addition of cold water to address cavitation, the recovered water temperature is only around 70°C. Furthermore, the open recovery system allows air to enter the condensate recovery piping, which can easily cause corrosion. Although open systems offer simplicity and low investment, they are increasingly losing value due to significant heat loss and severe corrosion.

[0006] (2) Closed system

[0007] The condensate collection tank in this system is closed, and the condensate pressure within the system is always maintained above atmospheric pressure, keeping the condensate temperature below its boiling point at that pressure, thus fully utilizing the condensate's thermal energy. Furthermore, the condensate never comes into contact with the atmosphere, eliminating the corrosion issues common in open systems.

[0008] The current closed condensate water recovery system, when multiple steam-using equipment are connected to the same network and the steam-using equipment are in different working states, the back pressure of the condensate water recovery system fluctuates when the steam-using equipment is in different working states, which causes the working state of the related steam-using equipment to be disorderly, and even the steam-using equipment cannot drain water. Specifically, when one steam-using equipment is in a high-pressure drainage state, the back pressure of the condensate water recovery system is determined by the steam-using equipment, and the pressure of the steam-using equipment in a low-pressure working state is lower than the back pressure, so that the steam-using equipment cannot drain water, which causes the working state of the steam-using equipment to be disorderly. Moreover, since the pressure in the condensate water collection tank of the closed condensate water recovery system is relatively high, the condensate water is relatively high in temperature, and cavitation is prone to occur.

[0009] Therefore, how to avoid the working disorder of the steam-using equipment, and even the non-working condition, while weakening the cavitation problem, is a technical problem to be solved by those skilled in the art at present. SUMMARY

[0010] Therefore, how to avoid the working disorder of the steam-using equipment, and even the non-working condition, while weakening the cavitation problem, is a technical problem to be solved by those skilled in the art at present.

[0011] Another object of the present application is to provide a closed condensate water recovery system having the closed condensate tank system.

[0012] In order to achieve the above object, the present application provides the following technical solutions.

[0013] A closed condensate tank system, comprising:

[0014] a condensate tank having a condensate water inlet, a flash steam outlet, and a pressure sensor for detecting the pressure in the condensate tank;

[0015] a steam ejector having a first steam inlet in communication with a main steam inlet pipeline, a second steam inlet in communication with the flash steam outlet, and a steam outlet in communication with steam-using equipment;

[0016] a proportional regulating valve connected in series to the main steam inlet pipeline;

[0017] a controller for reducing the opening degree of the proportional regulating valve when the pressure in the condensate tank exceeds the upper limit of a pressure threshold range, and increasing the opening degree of the proportional regulating valve when the pressure in the condensate tank is lower than the lower limit of the pressure threshold range, wherein the upper limit of the pressure threshold range is less than the atmospheric pressure.

[0018] Optionally, in the closed condensate tank system, a first end of the flash steam outlet is in communication with the condensate tank, and a second end of the flash steam outlet is a flash steam outlet end, and a spiral blade for capturing water droplets in steam is arranged in the channel of the flash steam outlet.

[0019] Optionally, in the closed condensate tank system, the passage of the flash steam outlet is a tapered passage from the first end to the second end of the flash steam outlet, and the spiral blade is a tapered spiral blade arranged along the tapered passage.

[0020] Optionally, in the closed condensate tank system, a water trapping net is arranged in the condensate tank and is arranged at one end of the condensate tank close to the flash steam outlet.

[0021] Optionally, in the closed condensate tank system, a pressure equalizing water distribution pipe is further arranged in the condensate tank and is in communication with the condensate water inlet.

[0022] Optionally, in the closed condensate tank system, a guide vane for guiding the condensate water to the condensate water outlet is arranged on the bottom wall of the condensate tank away from the one end of the flash steam outlet.

[0023] Optionally, in the closed condensate tank system, the guide vane comprises a plurality of involute guide vanes which are centrally symmetrical along the axis of the condensate tank.

[0024] Optionally, in the closed condensate tank system, the involute guide vane extends vertically upward along the bottom wall of the condensate tank, and the height of the involute guide vane gradually increases from the axis to the outer wall of the condensate tank.

[0025] The closed condensate tank system provided by the application adopts a closed system and is relatively isolated from the ambient air, so that steam can be saved, better oxygen removal effect can be achieved, the service life of the system can be prolonged, and equipment investment can be reduced. The closed condensate water recovery system can adjust the condensate tank to be under negative pressure through the steam ejector, and can adjust the pressure of the condensate tank within a pressure threshold range through the opening degree of the proportional regulating valve, so that the back pressure of the steam-using equipment after the drain valve is stable and lower than the atmospheric pressure. The application solves the problem of disorder of the working conditions of the steam-using equipment caused by the common network of multiple steam-using equipment, and even the problem of no drainage.

[0026] Since the internal pressure of the condensate tank is under negative pressure, the temperature of the recovered condensate water is reduced after low-temperature flashing in the condensate tank, so that the condensate pump does not cavitate. Moreover, the low-temperature condensate water has low pressure and is not easy to leak during transportation, so that the higher-temperature condensate water is easier to transport, the temperature difference between the water recovery process and the environment is smaller, heat exchange with the environment can be reduced to save energy, the requirement for the boiler water pump is reduced, at the same time, the temperature difference between the low-temperature condensate water and the boiler flue gas is large, the heat exchange efficiency is high, and the function of the boiler economizer can be better played.

[0027] A closed condensate water recovery system, comprising:

[0028] A steam supply device for supplying steam to a steam user device;

[0029] A water tank for providing water to form steam to the steam supply device;

[0030] A closed condensate tank system, for the closed condensate tank system as described above, the main steam inlet pipe is in communication with the steam supply device, the condensate water outlet of the condensate tank is in communication with the water tank through a condensate water recovery device, and the condensate water inlet of the condensate tank is in communication with the condensate water outlet of the steam user device through a condensate water collection pipe.

[0031] Optionally, in the closed condensate water recovery system described above, the steam user device comprises a high-pressure steam user device and a low-pressure steam user device;

[0032] The high-pressure steam user device is in communication with the steam supply device through a high-pressure steam supply pipe;

[0033] The low-pressure steam user device is in communication with the steam outlet of the steam ejector.

[0034] Optionally, in the closed condensate water recovery system described above, an air vent pipe is provided on the condensate tank, which is in communication with the condensate tank and the atmosphere, and an air vent valve is provided on the air vent pipe to control the opening and closing of the air vent pipe;

[0035] The air vent valve is linked with the condensate water recovery device.

[0036] Optionally, in the closed condensate water recovery system described above, the condensate water recovery device comprises a condensate water pump and a condensate water recovery pipe, the inlet of the condensate water pump is in communication with the condensate water outlet of the condensate tank, and the outlet of the condensate water pump is in communication with the water tank through the condensate water recovery pipe.

[0037] Optionally, in the closed condensate water recovery system described above, further comprising:

[0038] A liquid level sensor for detecting the liquid level of the condensate water in the condensate tank;

[0039] A drain valve provided on the condensate water recovery pipe to control the opening and closing of the condensate water recovery pipe;

[0040] The controller is used to control the opening of the air vent valve, the drain valve and the condensate water pump when the liquid level of the condensate water in the condensate tank exceeds the upper limit of the liquid level threshold range, and to control the closing of the air vent valve, the drain valve and the condensate water pump when the liquid level of the condensate water in the condensate tank is below the lower limit of the liquid level threshold range.

[0041] Optionally, in the closed condensate water recovery system, a condensate water inlet valve is arranged on the condensate water collection pipeline of the condensate water tank; a flash steam outlet valve is arranged on the flash steam outlet of the condensate water tank;

[0042] When the condensate water tank is in the flash state, the condensate water inlet valve and the flash steam outlet valve are in the open state, the vent valve, the drain valve and the condensate water pump are in the closed state, and the proportional regulating valve is in the opening degree regulating mode;

[0043] When the condensate water tank is in the drain state, the condensate water inlet valve and the flash steam outlet valve are in the closed state, the vent valve, the drain valve and the condensate water pump are in the open state, and the proportional regulating valve is in the opening degree fixed mode.

[0044] Optionally, in the closed condensate water recovery system, when the condensate water level in the condensate water tank exceeds the upper limit of the liquid level threshold range, the controller controls the condensate water inlet valve and the flash steam outlet valve to be closed;

[0045] When the condensate water level in the condensate water tank is below the lower limit of the liquid level threshold range, the controller controls the condensate water inlet valve and the flash steam outlet valve to be opened.

[0046] Optionally, in the closed condensate water recovery system, the condensate water tank is two in parallel;

[0047] Each of the condensate water tanks further comprises a standby flash state, when the condensate water tank is in the standby flash state, the condensate water inlet valve, the flash steam outlet valve, the vent valve, the drain valve and the condensate water pump are in the closed state, and the proportional regulating valve is in the opening degree fixed mode;

[0048] When the first condensate water tank enters the flash state, the second condensate water tank enters the drain state and the standby flash state in turn, until the first condensate water tank enters the drain state, and the second condensate water tank enters the flash state from the standby flash state.

[0049] Optionally, in the closed condensate water recovery system, when the condensate water level in the condensate water tank exceeds the upper limit of the liquid level threshold range, the condensate water tank enters the drain state; when the condensate water level in the condensate water tank is below the lower limit of the liquid level threshold range, the condensate water tank enters the standby flash state;

[0050] The condition for the condensate water tank to enter the flash state from the standby flash state is that the other condensate water tank enters the drain state.

[0051] Optionally, in the closed condensate water recovery system, the period length ratio of the flash state, the drain state and the standby flash state of the condensate water tank is 2:1:1.

[0052] The closed condensate water recovery system provided by the application has all the technical effects of the closed condensate tank system, and details are not repeated herein. BRIEF DESCRIPTION OF DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0054] Figure 1 The structure diagram of the closed condensate tank system disclosed in the embodiments of the present application is shown in the figure.

[0055] Figure 2 The structure diagram of the condensate tank disclosed in the embodiments of the present application is shown in the figure.

[0056] Figure 3 The internal structure diagram of the condensate tank disclosed in the embodiments of the present application is shown in the figure.

[0057] Figure 4 The bottom structure diagram of the condensate tank disclosed in the embodiments of the present application is shown in the figure.

[0058] Figure 5 The structure diagram of the closed condensate water recovery system disclosed in the embodiments of the present application is shown in the figure.

[0059] Figure 6 The condensate water collection system diagram of the closed condensate water recovery system disclosed in the embodiments of the present application is shown in the figure.

[0060] Figure 7 The condensate water recovery system diagram of the closed condensate water recovery system disclosed in the embodiments of the present application is shown in the figure.

[0061] Figures 1 to 7 The meanings of the reference signs in the figures are as follows:

[0062] 100 is a boiler, 200 is a steam receiver, 300 is a water tank, 400 is a softener, 500 is a condensate tank, 501 is a pressure sensor, 502 is a flash steam outlet, 503 is a flash steam outlet valve, 504 is a condensate inlet, 5041 is a condensate inlet valve, 505 is a liquid level sensor, 506 is a venting pipeline, 5061 is a venting valve, 507 is a condensate pump, 508 is a drain valve, 509 is a safety valve, 510 is a condensate tank body, 511 is a blowdown valve, 512 is a spiral blade, 513 is a water catching net, 514 is a uniform pressure distribution water distribution pipe, 515 is a guide vane, 600 is a steam ejector, 601 is a first steam inlet, 602 is a second steam inlet, 603 is a steam outlet, 700 is a high pressure steam using equipment, 701 is a high pressure trap, 800 is a low pressure steam using equipment, 801 is a low pressure trap, 900 is a proportional control valve. DETAILED DESCRIPTION

[0063] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0064] As shown in the drawings, the embodiments of the present application disclose a closed condensate tank system, which comprises a condensate tank 500, a steam ejector 600, a proportional control valve 900 and a controller (not shown in the drawings). Figure 1 The condensate tank 500 is a closed condensate tank, so that the condensate does not contact with the atmosphere, avoiding the corrosion problem existing in the open system. The condensate tank 500 has a condensate inlet 504, a flash steam outlet 502 and a pressure sensor 501 for detecting the pressure in the condensate tank 500.

[0065] The steam ejector 600 has a first steam inlet 601, a second steam inlet 602 and a steam outlet 603. The first steam inlet 601 is in communication with a main steam inlet pipeline, which is a pipeline connecting the boiler or the steam receiver. The second steam inlet 602 is in communication with the flash steam outlet 502, so that the flash steam in the condensate tank 500 enters the steam ejector 600. The steam outlet 603 is in communication with the steam using equipment, so that the steam is pressurized by the steam ejector 600 and then supplied to the steam using equipment.

[0066]

[0067] ​The skilled in the art can understand that the condensed water is collected by the steam equipment through the condensed water inlet 504 into the condensed water tank 500, and the saturated condensed water in the condensed water tank 500 is flashed to inevitably increase the pressure in the condensed water tank 500, which makes the pressure in the condensed water tank 500 keep higher than the atmospheric pressure, so the phenomenon that the steam equipment cannot drain water due to too high back pressure in the prior art occurs.

[0068] Since the reason that the steam equipment cannot drain water is that the internal pressure of the steam equipment is lower than the back pressure, the embodiment increases the steam ejector 600 to suck the flash steam in the condensed water tank 500, so that the pressure in the condensed water tank 500 keeps lower than the atmospheric pressure, and the internal pressure of the steam equipment will inevitably exceed the atmospheric pressure, thus completely avoiding the problem that the steam equipment cannot drain water due to the internal pressure being lower than the back pressure. The closed condensing tank system disclosed in the embodiment utilizes vacuum low-temperature flashing to obtain stable system backwater pressure, improves the number of flash distillations, and can obtain low-temperature condensed water.

[0069] In order to adjust the pressure in the condensed water tank 500 to keep it within a reasonable range, the embodiment also has a proportional regulating valve 900 connected in series on the main steam inlet pipeline, and the steam amount entering the steam ejector 600 from the main steam inlet pipeline can be adjusted by controlling the opening of the proportional regulating valve 900. For example, if the opening of the proportional regulating valve 900 is large, the steam amount entering the steam ejector 600 from the main steam inlet pipeline is large, and the corresponding steam amount entering the steam ejector 600 from the condensed water tank 500 is small; if the opening of the proportional regulating valve 900 is small, the steam amount entering the steam ejector 600 from the main steam inlet pipeline is small, and the corresponding steam amount entering the steam ejector 600 from the condensed water tank 500 is large.

[0070] The controller is used to reduce the opening of the proportional regulating valve 900 when the pressure in the condensed water tank 500 (measured by the pressure sensor 501) exceeds the upper limit of the pressure threshold range (which is less than the atmospheric pressure), so that the steam amount entering the steam ejector 600 from the main steam inlet pipeline is reduced, and the corresponding steam amount entering the steam ejector 600 from the condensed water tank 500 is increased, thereby reducing the pressure in the condensed water tank 500.

[0071] When the pressure in the condensed water tank 500 is lower than the lower limit of the pressure threshold range, the controller increases the opening of the proportional regulating valve 900. The steam amount entering the steam ejector 600 from the main steam inlet pipeline is increased, and the corresponding steam amount entering the steam ejector 600 from the condensed water tank 500 is reduced, thereby increasing the pressure in the condensed water tank 500. Through the pressure sensor 501, the proportional regulating valve 900 and the controller, the pressure in the condensed water tank 500 can be kept within a small fluctuation range of the pressure threshold range, and the fluctuation range and the pressure threshold range can be set according to the actual application scene.

[0072] The closed condensate recovery system provided by the present invention adopts a closed system and is relatively isolated from the ambient air. This can not only save steam and achieve a better deoxygenation effect, but also extend the service life of the system and reduce equipment investment. The closed condensate recovery system can adjust the condensate tank 500 to a negative pressure through the steam ejector 600, and can adjust the pressure of the condensate tank 500 within the pressure threshold range through the opening of the proportional control valve 900, so that the back pressure behind the steam trap of the steam-using equipment is relatively stable and lower than the atmospheric pressure, solving the problem of disordered working conditions of the steam-using equipment and even non-drainage when multiple steam-using equipment are connected to the same network. The present invention stabilizes the working conditions of the steam-using equipment by setting a unified and stable return water back pressure, avoiding disordered working conditions of the steam-using equipment or even non-working conditions.

[0073] Because the internal pressure of condensate tank 500 is negative, the temperature of the recovered condensate decreases after low-temperature flash evaporation within condensate tank 500, preventing cavitation in the condensate pump. Furthermore, the low-temperature condensate has a lower pressure and is less likely to leak during transportation, making it easier to transport higher-temperature condensate. The temperature difference between the return water and the ambient environment is smaller, reducing heat exchange with the environment, saving energy, and lowering the requirements for the boiler water pump. Furthermore, the large temperature difference between the low-temperature condensate and the boiler flue gas results in high heat exchange efficiency, which effectively functions as a boiler economizer.

[0074] In this embodiment, the condensate tank 500 is operated under the conditions of controlling the temperature at 70°C to 75°C and the pressure at 32 to 40 KPa, which can increase the amount of secondary steam by about 0.03 kg of steam per kilogram of condensate, and the condensate recovery rate is close to complete recovery, saving 10 to 15% of energy.

[0075] like Figure 2 and Figure 3 As shown, the first end of the flash steam outlet 502 is connected to the condensate tank 500, and the second end serves as the flash steam outlet. A spiral blade 512 is provided within the channel of the flash steam outlet 502 to capture water droplets in the steam. Flash steam within the condensate tank 500 is discharged from the flash steam outlet 502 under the suction of the steam ejector 600. Under the action of the spiral blade 512, the flash steam spirals upward from the first end toward the second end of the flash steam outlet 502. Centrifugal force separates the water droplets from the flash steam and they fall back into the condensate tank 500 along the inner wall of the flash steam outlet 502. In this embodiment, by adding the spiral blade 512 to the flash steam outlet 502, the water content of the flash steam discharged from the flash steam outlet 502 is reduced, creating conditions for a stable flow field between steam and water, reducing vibration and noise, mitigating equipment failures, and improving the accuracy of various sensors.

[0076] Further, in the direction from the first end to the second end of the flash steam outlet 502, the channel of the flash steam outlet 502 is a tapered channel, and the helical blade 512 is a tapered helical blade arranged along the tapered channel. During the discharge of the flash steam by the flash steam outlet 502, due to the gradual narrowing of the channel of the flash steam outlet 502, the centrifugal rotational flow rate of the flash steam is increased, further improving the separation amount of water droplets in the steam.

[0077] In an embodiment of the present application, the condensate tank 500 is provided with a water trapping net 513, and the water trapping net 513 is arranged at one end of the condensate tank 500 close to the flash steam outlet 502. Specifically, the water trapping net 513 can be a steel mesh layer. By arranging the water trapping net 513 at one end of the condensate tank 500 close to the flash steam outlet 502, the water trapping net 513 can avoid the condensate in the condensate tank 500, i.e. the water trapping net 513 is located above the liquid level of the condensate and in the path of the flash steam discharge to contact the flash steam and increase the contact surface area to trap water droplets in the steam.

[0078] Further, in an embodiment of the present application, the closed condensing tank system further comprises an equalizing water distribution pipe 514 arranged in the condensate tank 500 and communicating with the condensate inlet 504. The equalizing water distribution pipe 514, the plurality of small holes of the equalizing water distribution pipe 514 make the condensate enter the condensate tank 500 due to the sudden decrease in pressure and the sudden expansion of space, so that the saturated water becomes saturated vapor and saturated liquid under the pressure of the condensate tank 500.

[0079] As shown in Figure 3 and Figure 4 , the condensate tank 500 is provided with a flow guide piece 515 for guiding the condensate to the condensate outlet of the condensate tank 500 at the bottom wall away from the one end of the flash steam outlet 502. When it is necessary to discharge the condensate in the condensate tank 500, the condensate in the condensate tank 500 can be pumped out by the condensate pump 507. Under the pressure boosting of the condensate pump 507, the condensate in the condensate tank 500 flows to the direction of the condensate outlet under the action of the flow guide piece 515, so that the water outlet is more uniform and smooth.

[0080] Further, the flow guide piece 515 includes a plurality of involute flow guide pieces symmetrically arranged along the axis center of the condensate tank 500. Under the pressure boosting of the condensate pump 507, the condensate in the condensate tank 500 rotates to the condensate outlet under the action of the involute flow guide piece, further increasing the uniformity of the water outlet.

[0081] Further, the involute guide vanes extend vertically upward along the bottom wall of the condensate tank 500, and the height of the involute guide vanes gradually increases from the direction of the axis of the condensate tank 500 to the outer wall, that is, the height of the involute guide vanes close to the center of the condensate tank 500 is low, and the height of the involute guide vanes close to the edge of the condensate tank 500 is high. During the rotation of the water flow, the bubbles in the water are concentrated towards the center and overflow the liquid surface. In this embodiment, by providing the involute guide vanes with the above structure, the steam content of the condensate discharged from the condensate outlet is reduced, which creates conditions for stable flow field of steam and water, reduces vibration and noise, weakens equipment failure, and improves the accuracy of each sensor.

[0082] As shown in Figure 5 The present embodiment discloses a closed condensate recovery system, which comprises a steam supply device, a water tank 300 and a closed condensate tank system.

[0083] The steam supply device is used to provide steam for the steam-using device. The steam supply device can be a boiler 100, or a steam supply device comprising a boiler 100 and a steam cylinder 200.

[0084] The water tank 300 is used to provide water for forming steam for the steam supply device. The water in the water tank 300 should generally be softened by a softener 400 to avoid corrosion of the equipment.

[0085] The closed condensate tank system is the closed condensate tank system disclosed in the above embodiment. The main steam inlet pipeline is in communication with the steam supply device. The condensate outlet of the condensate tank 500 is in communication with the water tank 300 through a condensate recovery device. The condensate inlet 504 of the condensate tank 500 is in communication with the condensate discharge port of the steam-using device through a condensate collection pipeline. The condensate after being drained from the steam-using device is collected in the condensate tank 500 through the condensate collection pipeline. The condensate in the condensate tank 500 can be discharged into the water tank 300 through the condensate recovery device for utilization. It should be noted that the condensate in the condensate tank 500 can also be transported to other equipment through the condensate recovery device for utilization.

[0086] The closed condensate recovery system provided by the present application has all the technical effects of the above-mentioned closed condensate tank system, and will not be described here.

[0087] As shown in Figure 5 and Figure 6As shown, in a specific embodiment of the present invention, steam-consuming equipment may include a high-pressure steam-consuming equipment 700 and a low-pressure steam-consuming equipment 800. The high-pressure steam-consuming equipment 700 and the low-pressure steam-consuming equipment 800 are relative terms. The internal pressures of the two steam-consuming equipment are different, with the internal pressure of the high-pressure steam-consuming equipment 700 being greater than the internal pressure of the low-pressure steam-consuming equipment 800. A high-pressure steam trap 701 is provided at the drain outlet of the high-pressure steam-consuming equipment 700, and a low-pressure steam trap 801 is provided at the drain outlet of the low-pressure steam-consuming equipment 800.

[0088] The high-pressure steam user 700 is connected to the steam supply device via a high-pressure steam pipeline. The gas supply device (such as the steam cylinder 200 in this embodiment) directly supplies steam to the high-pressure steam user 700. The low-pressure steam user 800 is connected to the steam outlet 603 of the steam ejector 600. Since the steam ejector 600 receives steam from the steam cylinder 200 and the condensate tank 500, the steam source for the low-pressure steam user 800 includes the flash steam in the gas supply device (such as the steam cylinder 200 in this embodiment) and the condensate tank 500.

[0089] The closed condensate recovery system disclosed in this embodiment can provide stable working back pressure for both the high-pressure steam equipment 700 and the low-pressure steam equipment 800, that is, it provides a back pressure (in this case, negative pressure, that is, a slightly vacuum state) at which all equipment (high-pressure steam equipment 700 and low-pressure steam equipment 800) can work normally.

[0090] like Figure 7 As shown, the condensate recovery device may include a condensate pump 507 and a condensate recovery pipeline. The inlet of the condensate pump 507 is connected to the condensate outlet of the condensate tank 500, and the outlet of the condensate pump 507 is connected to the water tank 300 through the condensate recovery pipeline.

[0091] In order to further prevent cavitation of the condensate pump 507 of the condensate recovery device, in this embodiment, a vent pipe 506 connected to the condensate tank 500 and the atmosphere is provided on the condensate tank 500, and a vent valve 5061 for controlling the opening and closing of the vent pipe 506 is provided on the vent pipe 506. By opening the vent valve 5061, the condensate tank 500 can be connected to the atmosphere through the vent pipe 506; by closing the vent valve 5061, the condensate tank 500 can be isolated from the atmosphere.

[0092] The vent valve 5061 is linked with the condensate recovery device, that is, when the liquid level in the condensate tank 500 reaches a certain height and the condensate in the condensate tank 500 needs to be discharged to the water tank 300, the condensate recovery device needs to be opened, and at the same time, the vent valve 5061 needs to be opened, so that the condensate tank 500 is in communication with the atmosphere, so as to increase the pressure in the condensate tank 500, that is, to increase the inlet pressure head of the condensate pump 507, so as to prevent cavitation of the condensate pump 507. Unlike the existing technology which introduces steam to supplement pressure or returns the pump outlet to increase pressure, the embodiment opens the vent valve 5061 to make the condensate tank 500 communicate with the atmosphere, which avoids energy waste, improves the working conditions of the condensate pump, and reduces the cavitation rate.

[0093] In order to achieve the purpose of automatic drainage, in a specific embodiment of the present application, the closed condensate recovery system can further include a liquid level sensor 505 and a drainage valve 508.

[0094] The liquid level sensor 505 is used to detect the condensate level in the condensate tank 500. The drainage valve 508 is arranged on the condensate recovery pipeline and is used to control the opening and closing of the condensate recovery pipeline. When the drainage valve 508 is opened, the outlet of the condensate pump 507 can be kept in communication with the water tank 300. When drainage is not needed, the drainage valve 508 is in a closed state to avoid the condensate in the water tank 300 being pressed into the condensate tank 500 under the action of pressure difference.

[0095] The controller is used to control the vent valve 5061, the drainage valve 508 and the condensate pump 507 to be opened when the condensate level in the condensate tank 500 (measured by the liquid level sensor 505) exceeds the upper limit of the liquid level threshold range. The liquid level threshold range can be set according to the actual application scene. When the condensate level in the condensate tank 500 exceeds the upper limit of the liquid level threshold range, it indicates that the condensate level in the condensate tank 500 is too high, and the condensate in the condensate tank 500 needs to be drained. When draining water into the water tank 300, the vent valve 5061, the drainage valve 508 and the condensate pump 507 need to be opened. The vent valve 5061 is opened to make the condensate tank 500 communicate with the atmosphere, so as to prevent cavitation phenomenon of the condensate pump 507 during operation. The drainage valve 508 is opened to make the condensate recovery pipeline keep conducting, and under the pressure increase of the condensate pump 507, the condensate in the condensate tank 500 is pumped into the water tank 300.

[0096] When the condensate level in the condensate tank 500 is below the lower limit of the condensate level threshold range, the vent valve 5061, the drain valve 508 and the condensate pump 507 are controlled to be closed. When the condensate level in the condensate tank 500 reaches the lower limit of the condensate level threshold range, it indicates that the condensate level in the condensate tank 500 is sufficient, and the condensate generated by the steam using equipment can be collected continuously. The vent valve 5061 is closed to restore the pressure in the condensate tank 500 to the pressure threshold range, and the drain valve 508 and the condensate pump 507 are closed to make the condensate recovery pipeline in a cut-off state, so as to control the condensate tank 500 and the water tank 300 to be disconnected.

[0097] As shown in FIGS. 1, 2 and 3, in a specific embodiment of the present application, the condensate recovery pipeline of the condensate tank 500 is provided with a condensate inlet valve 5041, and the flash steam outlet 502 of the condensate tank 500 is provided with a flash steam outlet valve 503. Figure 2 Figure 6 As shown in FIGS. 1, 2 and 3, in a specific embodiment of the present application, the condensate recovery pipeline of the condensate tank 500 is provided with a condensate inlet valve 5041, and the flash steam outlet 502 of the condensate tank 500 is provided with a flash steam outlet valve 503.

[0098] The flash state of the condensate tank 500 refers to that the condensate of the steam using equipment is vacuum flashed into the condensate tank 500, the flash steam is discharged from the flash steam outlet 502 and enters the steam ejector 600, and the condensate is collected in the condensate tank 500.

[0099] When the condensate tank 500 is in the flash state, the condensate inlet valve 5041 and the flash steam outlet valve 503 are in an open state, the vent valve 5061, the drain valve 508 and the condensate pump 507 are in a closed state, and the proportional regulating valve 900 is in an opening degree regulating mode. Since the pressure in the condensate tank 500 needs to be controlled in the pressure threshold range only when the condensate tank 500 is in the flash state, the controller adjusts the opening degree of the proportional regulating valve 900 according to the relationship between the pressure in the condensate tank 500 and the pressure threshold range only when the condensate tank 500 is in the flash state. In other words, the proportional regulating valve 900 adjusts the opening degree according to the relationship between the pressure in the condensate tank 500 and the pressure threshold range only when the condensate inlet valve 5041 and the flash steam outlet valve 503 are in the open state, and the vent valve 5061, the drain valve 508 and the condensate pump 507 are in the closed state.

[0100] The drain state of the condensate tank 500 refers to the process of draining the condensate in the condensate tank 500 into the water tank 300. When the condensate tank 500 is in the drain state, the condensate inlet valve 5041 and the flash steam outlet valve 503 are in a closed state, the vent valve 5061, the drain valve 508 and the condensate pump 507 are in an open state, and the proportional regulating valve 900 is in an opening degree fixed mode.

[0101] ​When the condensate tank 500 is in the drainage state, the condensate tank 500 is in communication with the atmosphere, and the opening degree of the proportional regulating valve 900 does not need to be adjusted to adjust the vacuum degree of the condensate tank 500. Therefore, when the condensate tank 500 is in the drainage state, the opening degree of the proportional regulating valve 900 does not change and is not adjusted according to the pressure value in the condensate tank 500, or when the condensate inlet valve 5041 and the flash steam outlet valve 503 are in the closed state, and the vent valve 5061, the drainage valve 508 and the condensate pump 507 are in the open state, the opening degree of the proportional regulating valve 900 is not adjusted according to the pressure value in the condensate tank 500.

[0102] When there is only one condensate tank 500, the opening and closing of the condensate inlet valve 5041 and the flash steam outlet valve 503 can be controlled according to the condensate level in the condensate tank 500. That is, if there is only one condensate tank 500, the condensate tank 500 can only include two working states of the flash state and the drainage state.

[0103] When the condensate level in the condensate tank 500 exceeds the upper limit of the threshold range, the controller controls the condensate inlet valve 5041 and the flash steam outlet valve 503 to be closed, and the condensate tank 500 enters the drainage state; when the condensate level in the condensate tank 500 is lower than the lower limit of the threshold range, the controller controls the condensate inlet valve 5041 and the flash steam outlet valve 503 to be opened, and the condensate tank 500 enters the flash state.

[0104] When there are two condensate tanks 500 in parallel, in addition to the flash state and the drainage state, the condensate tank 500 should also include a standby flash state. When the condensate tank 500 is in the standby flash state, the condensate inlet valve 5041, the flash steam outlet valve 503, the vent valve 5061, the drainage valve 508 and the condensate pump 507 are all in the closed state, and the proportional regulating valve 900 is in the fixed opening degree mode.

[0105] When the first condensate tank 500 (i.e., one of the condensate tanks 500) enters the flash state, the second condensate tank 500 (i.e., the other condensate tank 500) enters the drainage state and the standby flash state in turn, until the first condensate tank 500 enters the drainage state, and the second condensate tank 500 enters the flash state from the standby flash state.

[0106] When the condensate level in the condensate tank 500 exceeds the upper limit of the threshold range, the condensate tank 500 enters the drainage state; when the condensate level in the condensate tank 500 is lower than the lower limit of the threshold range, the condensate tank 500 enters the standby flash state; and the condensate tank 500 enters the flash state from the standby flash state when the other condensate tank 500 enters the drainage state.

[0107] For the convenience of introducing the switching process of the two condensate tanks 500, one of the condensate tanks is taken as the first condensate tank and the other as the second condensate tank for the introduction below.

[0108] When the first condensate tank is in the flashing state, the second condensate tank is in the draining state, until the draining state ends and the second condensate tank enters the standby flashing state, until the first condensate tank ends the flashing state and switches to the draining state, at this time, the second condensate tank switches to the flashing state at the same time, and one condensate tank is always in the flashing state, and the cycle is repeated.

[0109] When the first condensate tank switches from the standby flashing state to the flashing state, the condensate inlet valve and the flashing steam outlet valve of the first condensate tank are opened, the pressure sensor of the first condensate tank works in association with the proportional regulating valve, the vacuum degree in the first condensate tank is maintained, until the water level in the tank reaches the upper limit value of the pressure threshold range, the flashing state ends, the condensate inlet valve and the flashing steam outlet valve of the first condensate tank are closed, the vent valve, the drain valve and the condensate pump of the first condensate tank are opened, and the first condensate tank enters the draining state, until the condensate level reaches the lower limit value of the pressure threshold range, the drain valve, the condensate pump and the vent valve of the first condensate tank are closed, and the first condensate tank enters the standby flashing state, and the cycle is repeated.

[0110] Specifically, the period length ratio of the flashing state, the draining state and the standby flashing state of the condensate tank 500 is 2:1:1.

[0111] It should be noted that each of the embodiments in the present specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same parts between the embodiments can be referred to each other.

[0112] As shown in the present application and claims, unless the context clearly indicates otherwise, "one", "a", "an" and / or "the" do not specifically refer to the singular, but also include the plural. Generally, the terms "comprise" and "include" only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements. The element defined by the statement "comprises a" does not exclude the presence of another identical element in the process, method, product or device comprising the element.

[0113] In the description of the embodiments of the present application, unless otherwise specified, " / " represents or, for example, A / B can represent A or B; "and / or" in this paper only describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which means that there are three cases of A alone, A and B together, and B alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0114] Hereinafter, the terms "first", "second", etc. are used only for the purpose of description, and are not to be construed as indicating or implying relative importance or an indicated number of technical features. Thus, features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features.

[0115] The principles and implementations of the present application are described herein with specific examples. The above description of the embodiments is only for the purpose of understanding the core idea of the present application. It should be pointed out that, for those skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A closed condensate tank system characterized in that, The application relates to a closed condensate tank system. The closed condensate tank system comprises: a condensate tank (500) having a condensate inlet (504), a flash steam outlet (502) and a pressure sensor (501) for detecting the pressure in the condensate tank (500); a steam ejector (600) having a first steam inlet (601) in communication with a main steam supply pipeline, a second steam inlet (602) in communication with the flash steam outlet (502) and a steam outlet (603) in communication with a steam user; a proportional control valve (900) connected in series to the main steam supply pipeline; 2. The closed condensate tank system of claim 1, wherein, a controller for reducing the opening of the proportional control valve (900) when the pressure in the condensate tank (500) exceeds the upper limit of a pressure threshold range, and for increasing the opening of the proportional control valve (900) when the pressure in the condensate tank (500) is lower than the lower limit of the pressure threshold range, wherein the upper limit of the pressure threshold range is less than the atmospheric pressure.

3. The closed condensate tank system of claim 2, wherein, The first end of the flash steam outlet (502) is in communication with the condensate tank (500), and the second end is a flash steam outlet end. A spiral blade (512) for capturing water droplets in steam is arranged in the channel of the flash steam outlet (502).

4. The closed condensate tank system of claim 1, wherein, The channel of the flash steam outlet (502) is a tapered channel from the first end to the second end of the flash steam outlet (502), and the spiral blade (512) is a tapered spiral blade arranged along the tapered channel.

5. The closed condensate tank system of claim 1, wherein, A water capturing net (513) is arranged in the condensate tank (500) and is arranged at one end of the condensate tank (500) close to the flash steam outlet (502).

6. The closed condensate tank system according to any one of claims 1-5, characterized in that, A pressure equalizing water distribution pipe (514) is further arranged in the condensate tank (500) and is in communication with the condensate inlet (504).

7. The closed condensate tank system of claim 6, wherein, A guide vane (515) is arranged on the bottom wall of the condensate tank (500) away from the flash steam outlet (502) and is used for guiding the condensate to the condensate outlet of the condensate tank (500).

8. The closed condensate tank system of claim 7, wherein, The guide vane (515) comprises a plurality of involute guide vanes which are centrally symmetric along the axis of the condensate tank (500).

9. A closed condensate water recovery system, characterized in that: The involute guide vanes extend vertically upward along the bottom wall of the condensate tank (500), and the height of the involute guide vanes gradually increases from the axis to the outer wall of the condensate tank (500). The application relates to a closed condensate tank system. The closed condensate tank system comprises: a steam supply device for supplying steam to a steam user; 10. The closed condensate recovery system of claim 9, wherein, a water tank (300) for providing water for forming steam for the steam supply device; a closed condensate tank system as claimed in any one of claims 1-8, wherein the main steam supply pipeline is in communication with the steam supply device, the condensate outlet of the condensate tank (500) is in communication with the water tank (300) through a condensate recovery device, and the condensate inlet (504) of the condensate tank (500) is in communication with the condensate drainage outlet of the steam user through a condensate collection pipeline. The steam user comprises a high-pressure steam user (700) and a low-pressure steam user (800). The high-pressure steam user (700) is in communication with the steam supply device through a high-pressure steam supply pipeline. The low-pressure steam device (800) is in communication with the steam outlet (603) of the steam ejector (600).

11. The closed condensate recovery system of claim 9, wherein, The condensate tank (500) is provided with a venting pipeline (506) in communication with the condensate tank (500) and the atmosphere, and the venting pipeline (506) is provided with a venting valve (5061) for controlling the opening and closing of the venting pipeline (506). The venting valve (5061) is linked with the condensate recovery device.

12. The closed condensate recovery system of claim 11, wherein, The condensate recovery device comprises a condensate pump (507) and a condensate recovery pipeline, the inlet of the condensate pump (507) is in communication with the condensate outlet of the condensate tank (500), and the outlet of the condensate pump (507) is in communication with the water tank (300) through the condensate recovery pipeline.

13. The closed condensate recovery system of claim 12, wherein, Further comprising: a liquid level sensor (505) for detecting the condensate liquid level in the condensate tank (500); a drain valve (508) provided on the condensate recovery pipeline for controlling the opening and closing of the condensate recovery pipeline; The controller is used to control the venting valve (5061), the drain valve (508) and the condensate pump (507) to be opened when the condensate liquid level in the condensate tank (500) exceeds the upper limit of the liquid level threshold range, and to be closed when the condensate liquid level in the condensate tank (500) is below the lower limit of the liquid level threshold range.

14. The closed condensate recovery system of claim 13, wherein, The condensate inlet valve (5041) is provided on the condensate collection pipeline of the condensate tank (500); and the flash steam outlet valve (503) is provided on the flash steam outlet (502) of the condensate tank (500); When the condensate tank (500) is in the flash evaporation state, the condensate inlet valve (5041) and the flash steam outlet valve (503) are in the opened state, the venting valve (5061), the drain valve (508) and the condensate pump (507) are in the closed state, and the proportional regulating valve (900) is in the opening degree regulating mode; When the condensate tank (500) is in the drainage state, the condensate inlet valve (5041) and the flash steam outlet valve (503) are in the closed state, the venting valve (5061), the drain valve (508) and the condensate pump (507) are in the opened state, and the proportional regulating valve (900) is in the opening degree fixed mode.

15. The closed condensate recovery system of claim 14, wherein, When the condensate liquid level in the condensate tank (500) exceeds the upper limit of the liquid level threshold range, the controller controls the condensate inlet valve (5041) and the flash steam outlet valve (503) to be closed; When the condensate liquid level in the condensate tank (500) is below the lower limit of the liquid level threshold range, the controller controls the condensate inlet valve (5041) and the flash steam outlet valve (503) to be opened.

16. The closed condensate recovery system of claim 14, wherein, The condensate tank (500) is two in parallel; Each of the condensate tanks (500) further comprises a to-be-flashed state, when the condensate tank (500) is in the to-be-flashed state, the condensate inlet valve (5041), the flash steam outlet valve (503), the vent valve (5061), the drain valve (508) and the condensate pump (507) are all in the closed state, and the proportional regulating valve (900) is in the fixed opening degree mode; When the first condensate tank (500) enters the flashed state, the second condensate tank (500) enters the to-be-flashed state and the drained state in turn, until the first condensate tank (500) enters the drained state, and the second condensate tank (500) enters the flashed state from the to-be-flashed state.

17. The closed condensate recovery system of claim 16, wherein, When the condensate level in the condensate tank (500) exceeds the upper limit of the condensate level threshold range, the condensate tank enters the drained state; when the condensate level in the condensate tank (500) is lower than the lower limit of the condensate level threshold range, the condensate tank enters the to-be-flashed state; The condensate tank (500) enters the flashed state from the to-be-flashed state when another condensate tank (500) enters the drained state.

18. The closed condensate recovery system of claim 16, wherein, The cycle time length ratio of the flashed state, the drained state and the to-be-flashed state of the condensate tank (500) is 2:1:1.

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