Steam pipeline condensate recovery method and system

Abstract

The present invention discloses a method and system for recovering condensate from steam pipelines. The steam pipeline condensate recovery system is connected to a drain pipe on the steam pipeline and includes an introduction mechanism, a collection mechanism, a heating mechanism, and a steam exhaust mechanism. The introduction mechanism is used to introduce condensate from the drain pipe; the collection mechanism is used to collect the condensate introduced by the introduction mechanism; the heating mechanism is used to heat the condensate collected by the collection mechanism into steam; and the steam exhaust mechanism is used to return the steam heated by the heating mechanism to the steam pipeline. The operating costs of this invention are essentially offset by the steam costs saved, resulting in an extremely low cost. However, the impact of condensate discharge on production site safety and environmental protection is resolved, and it has great practical value in actual production activities.

Description

Technical Field

[0001] The present invention relates to the technical field of condensate recovery, and in particular discloses a method and system for recovering condensate from a steam pipeline. Background Art

[0002] Steam is a clean and safe energy carrier widely used in production processes. However, during steam transportation, heat is inevitably lost from the pipes to the environment through both convection and radiation, with radiation being the primary method. After releasing its latent heat of vaporization, steam in the pipes turns into saturated condensate at the same temperature. Because steam pressure is greater than atmospheric pressure, the condensate can contain approximately 25% of the total heat of the steam. Therefore, it is essential to recover both the condensate and the heat it carries.

[0003] In addition, the disadvantages of condensed water discharge are as follows:

[0004] 1) Condensate from pipes is usually discharged directly into the air, wasting energy.

[0005] 2) The discharge of condensate affects the safety and environment of the production site.

[0006] 3) Condensate splashing onto equipment and pipes will corrode them or cause them to mold.

[0007] Current condensate recovery technologies can be roughly divided into two types: open recovery systems and closed recovery systems.

[0008] Main technical solutions for condensate water recovery:

[0009] 1. Open recovery system

[0010] The open recovery system recycles condensate back into the boiler's feedwater tank, leaving the condensate collection tank open to the atmosphere. When the condensate pressure is too low to reach the reuse site by its own pressure, a high-temperature water pump is used to pump the condensate.

[0011] This system has the advantages of simple equipment, easy operation, and low initial investment. However, it occupies a large area, resulting in poor economic benefits and significant environmental pollution. Furthermore, since the condensate comes into direct contact with the atmosphere, the dissolved oxygen concentration in the condensate increases, which can easily cause equipment corrosion. This system is suitable for small steam supply systems.

[0012] 2. Closed recovery system

[0013] In a closed-loop recovery system, the condensate collection tank and all piping are kept under constant positive pressure, creating a closed system. Condensate is directly recycled to the boiler, with the temperature loss occurring only in the cooling portion of the piping network. This closed-loop system ensures water quality and reduces water treatment costs for the water being recycled to the boiler. While this system offers advantages such as high economic returns and a long equipment life, it also requires a relatively high initial investment and is inconvenient to operate.

[0014] 3. Expansion heat exchange recovery method

[0015] The expansion heat recovery method maximizes the use of condensate heat. Firstly, through expansion flash evaporation, low-pressure steam is generated and supplied to low-pressure steam users. Secondly, through heat exchange through a heat exchanger, the high-temperature condensate is used to heat boiler feed water (economizer). The high-temperature condensate can also be used as boiler feed water. However, the disadvantages are complex equipment layout, the presence of flash evaporation, and low thermal energy utilization.

[0016] 4. Closed pump into boiler method

[0017] The closed pump-to-boiler method uses steam-using equipment without a steam trap. Instead, a positive displacement pump or ejector pumps the condensate, a mixture of steam and water, into the boiler. However, this method has low thermal energy utilization and is limited by compressor capacity. It is only suitable for condensate recovery at low flow rates and with relatively uniform pressure in steam-using equipment.

[0018] In summary, all technical solutions for condensate piped through the boiler utilize different return methods, each with varying condensate pressure and temperature recovery efficiencies. The biggest problem with these solutions is that if there's no condensate pipe near the steam transmission pipeline (approximately 200 meters), a new, long-distance condensate pipe must be constructed. This creates a significant fixed cost burden, potentially requiring even 10 years of investment recovery.

[0019] Therefore, to this day, most energy users still use direct discharge to treat condensate from steam pipelines. Effectively recycling condensate from steam pipelines while controlling the associated costs is a pressing technical challenge. Summary of the Invention

[0020] The present invention provides a steam pipeline condensate recovery method and system, aiming to solve the technical problem that the existing technology cannot effectively recover steam pipeline condensate and control the corresponding cost.

[0021] One aspect of the present invention relates to a steam pipeline condensate recovery system, which is connected to a drainage pipe on the steam pipeline and includes an introduction mechanism, a collection mechanism, a heating mechanism and a steam exhaust mechanism, wherein:

[0022] An introduction mechanism is used to introduce condensed water from the drainage pipe;

[0023] The collecting mechanism is connected to the introducing mechanism and is used to collect the condensed water introduced by the introducing mechanism;

[0024] A heating mechanism is provided near the collecting mechanism and is used to heat the condensed water collected by the collecting mechanism into steam;

[0025] The steam exhaust mechanism is connected to the collecting mechanism and is used to return the steam heated by the heating mechanism to the steam pipeline.

[0026] Furthermore, the introduction mechanism includes a water inlet, which is connected to the drainage pipe and is used to introduce condensed water in the drainage pipe.

[0027] Furthermore, the collecting mechanism includes a condensed water storage tank, which is connected to the water inlet and is used to collect the condensed water introduced by the water inlet.

[0028] Furthermore, the steam exhaust mechanism includes a steam exhaust port, which is connected to the condensate storage tank and the steam exhaust pipe respectively, and is used to return the steam heated by the heating mechanism to the steam pipeline through the steam exhaust pipe.

[0029] Furthermore, the heating mechanism includes a heater and an electrical control box. The heater is electrically connected to the electrical control box. The heater is arranged in the condensed water storage tank. The electrical control box is arranged close to the outer wall of the condensed water storage tank. The heater is used to heat the condensed water collected in the condensed water storage tank into steam.

[0030] Furthermore, the heating mechanism also includes a water level gauge, which includes a low water level gauge, a middle water level gauge and a high water level gauge. The low water level gauge, the middle water level gauge and the high water level gauge are arranged at the low water level position, the middle water level position and the high water level position in the condensate storage tank from low to high; the electric control box is electrically connected to the low water level gauge through the lower water level switch, the electric control box is electrically connected to the middle water level gauge through the middle water level switch, and the electric control box is electrically connected to the high water level gauge through the upper water level switch.

[0031] Furthermore, a drain pipe is provided at the bottom of the condensed water storage tank, the drain pipe is connected to the condensed water storage tank, a drain valve is provided on the drain pipe, and the drain valve is electrically connected to the electric control box.

[0032] Furthermore, a drain pipe is provided on the top of the condensed water storage tank, the drain pipe is connected to the condensed water storage tank, a drain valve is provided on the drain pipe, and the drain valve is electrically connected to the electric control box.

[0033] Another aspect of the present invention relates to a steam pipeline condensate recovery method, which is applied to the above-mentioned steam pipeline condensate recovery system and comprises the following steps:

[0034] During operation, condensate water flows down the drain pipe to the condensate storage tank;

[0035] The steam evaporated from the condensate storage tank rises to the steam pipe through the drain pipe;

[0036] The steps for steam evaporated from the condensate storage tank to rise to the steam pipe through the drain pipe include:

[0037] Check the high water level gauge. When the condensate reaches the high water level, open the drain valve for emergency drainage.

[0038] Detect the middle water level gauge. When the condensed water reaches the middle water level, the middle water level switch is closed, the heater is powered on, and the condensed water in the condensed water storage tank begins to heat and evaporate.

[0039] Detect the low water level gauge. When the condensed water drops below the lower water level, the lower water level switch is disconnected, the heater is disconnected from the power supply, and the condensed water in the condensed water storage tank no longer evaporates.

[0040] The timing starts from the moment the heater is turned on. When the set first heating time is reached, the heater will be turned off directly regardless of whether the water level is closed or not.

[0041] At the same time, the water level gauge is detected to see if it is in a closed state. If it is closed, the second heating time starts from the moment the heating stops. If the set second heating time is reached, the heater is powered on to continue heating. At the same time, the third heating time starts.

[0042] Another aspect of the present invention relates to a steam pipeline condensate recovery method, which is applied to the above-mentioned steam pipeline condensate recovery system and comprises the following steps:

[0043] During operation, condensate drops from the drain pipe to the condensate storage tank;

[0044] The steam evaporated from the condensate storage tank rises to the steam pipe through the exhaust pipe;

[0045] The steps for steam evaporated from the condensate storage tank to rise to the steam pipe through the exhaust pipe include:

[0046] Check the high water level gauge. When the condensate reaches the high water level, open the drain valve for emergency drainage.

[0047] Detect the middle water level gauge. When the condensed water reaches the middle water level, the middle water level switch is closed, the heater is powered on, and the condensed water in the condensed water storage tank begins to heat and evaporate.

[0048] Check the low water level gauge. When the condensed water drops below the lower water level, the lower water level switch is disconnected, the heater is disconnected from the power supply, and the condensed water in the condensed water storage tank no longer evaporates.

[0049] The beneficial effects achieved by the present invention are:

[0050] The present invention provides a method and system for recovering condensed water from a steam pipeline. The condensed water recovery system for a steam pipeline is connected to a drainage pipe on the steam pipeline and includes an introduction mechanism, a collection mechanism, a heating mechanism, and a steam exhaust mechanism. The introduction mechanism is used to introduce condensed water from the drainage pipe; the collection mechanism is used to collect condensed water introduced by the introduction mechanism; the heating mechanism is used to heat the condensed water collected by the collection mechanism into steam; and the steam exhaust mechanism is used to return the steam heated by the heating mechanism to the steam pipeline. The method and system for recovering condensed water from a steam pipeline provided by the present invention installs a condensed water recovery device on the original condensed water drainage pipe, and restores the condensed water to a steam state through electric heating, so that the pipeline no longer discharges condensed water. The operating cost of the present invention is basically offset by the steam cost saved, and the cost is extremely low; however, it solves the impact of the discharge of condensed water on the safety and environmental protection of the production site, and has great practical value in actual production activities. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a structural schematic diagram of a first embodiment of a steam pipeline condensate recovery system according to the present invention;

[0052] Figure 2 This is a structural schematic diagram of a second embodiment of a steam pipeline condensate recovery system according to the present invention;

[0053] Figure 3 This is a schematic structural diagram of a third embodiment of a steam pipeline condensate recovery system according to the present invention;

[0054] Figure 4 This is a schematic structural diagram of a fourth embodiment of a steam pipeline condensate recovery system according to the present invention;

[0055] Figure 5 This is a schematic diagram showing the principle of a first embodiment of a steam pipeline condensate recovery system connected to a steam pipeline according to the present invention;

[0056] Figure 6 This is a schematic diagram showing the principle of a second embodiment of a steam pipeline condensate recovery system connected to a steam pipeline according to the present invention;

[0057] Figure 7 This is a schematic flow chart of a first embodiment of a method for recovering condensed water from a steam pipeline according to the present invention;

[0058] Figure 8 This is a flow chart of a second embodiment of a method for recovering condensed water from a steam pipeline according to the present invention.

[0059] Description of Figure Numbers:

[0060] 10. Water inlet; 20. Condensate storage tank; 30. Steam exhaust port; 31. Steam exhaust pipe; 41. Heater; 43. Water level gauge; 51. Drain pipe; 52. Drain valve; 61. Drain pipe; 62. Drain valve; 100. Steam pipe; 200. Drain pipe. DETAILED DESCRIPTION

[0061] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0062] like Figures 1 to 4 As shown, the first embodiment of the present invention proposes a steam pipe condensate recovery system, which is connected to the drain pipe 200 on the steam pipe 100 and includes an introduction mechanism, a collection mechanism, a heating mechanism, and an exhaust mechanism, wherein the introduction mechanism is used to introduce condensate in the drain pipe 200; the collection mechanism is connected to the introduction mechanism and is used to collect the condensate introduced by the introduction mechanism; the heating mechanism is arranged near the collection mechanism and is used to heat the condensate collected by the collection mechanism into steam; the exhaust mechanism is connected to the collection mechanism and is used to return the steam heated by the heating mechanism to the steam pipe. In this embodiment, the introduction mechanism, the collection mechanism, the heating mechanism, and the exhaust mechanism can adopt existing mechanical or functional equipment, all of which are within the scope of protection of this patent.

[0063] Preferably, see Figures 1 to 6 The steam pipe condensate recovery system proposed in this embodiment includes a water inlet 10, which is connected to the drainage pipe 200 and is used to introduce condensate in the drainage pipe.

[0064] Further, see Figures 1 to 6 The steam pipeline condensate recovery system proposed in this embodiment includes a collection mechanism comprising a condensate storage tank 20 , which is connected to the water inlet 10 and is used to collect the condensate introduced by the water inlet 10 .

[0065] Further, see Figures 1 to 6 The steam pipeline condensate recovery system proposed in this embodiment has a steam exhaust mechanism including a steam exhaust port 30, which is respectively connected to the condensate storage tank 20 and the steam exhaust pipe 31, and is used to return the steam heated by the heating mechanism to the steam pipeline through the steam exhaust pipe 31.

[0066] Preferably, see Figures 1 to 6The steam pipeline condensate recovery system proposed in this embodiment comprises a heating mechanism including a heater 41 and an electrical control box. The heater 41 is electrically connected to the electrical control box. The heater 41 is disposed in the condensate storage tank 20. The electrical control box is disposed near the outer wall of the condensate storage tank 20. The heater 41 is used to heat the condensate collected in the condensate storage tank 20 into steam. Specifically, the heating mechanism also includes a water level gauge 43. The water level gauge 43 includes a low water level gauge, a middle water level gauge, and a high water level gauge. The low water level gauge, the middle water level gauge, and the high water level gauge are disposed in descending order at the low water level position, the middle water level position, and the high water level position in the condensate storage tank 20. The electrical control box is electrically connected to the low water level gauge via a lower water level switch, the electrical control box is electrically connected to the middle water level gauge via a middle water level switch, and the electrical control box is electrically connected to the high water level gauge via an upper water level switch. A drain pipe 51 is provided at the bottom of the condensate tank 20. This drain pipe 51 is connected to the condensate tank 20 and has a drain valve 52 installed on it. This drain valve 52 is electrically connected to the electrical control box. A drain pipe 61 is provided at the top of the condensate tank 20. This drain pipe 61 is connected to the condensate tank 20 and has a drain valve 62 installed on it. This drain valve 62 is electrically connected to the electrical control box. The steam pipeline condensate recovery system proposed in this embodiment detects the high water level gauge. When the electric control box recognizes that the condensate detected by the high water level gauge has reached the high water level, the drain valve is opened for emergency drainage. When the electric control box recognizes that the condensate detected by the middle water level gauge has reached the middle water level, the middle water level switch is controlled to close, the heater is powered on, and the condensate in the condensate storage tank begins to be heated and evaporated. When the electric control box recognizes that the condensate detected by the low water level gauge has dropped below the lower water level, the lower water level switch is controlled to open, the heater is powered off, and the condensate in the condensate storage tank stops evaporating. The timing starts from when the heater is turned on, and when the set first heating time (for example, 5400 / m s ), regardless of whether the middle water level is closed or not, the heater is directly disconnected; at the same time, the lower water level gauge is detected to see if it is in a closed state. If it is in a closed state, the second heating time is counted from the moment the heating stops. If the set second heating time (150s) is reached, the heater is powered on to continue heating, and at the same time, the third heating time is counted.

[0067] A first embodiment of the present invention relates to a steam pipeline condensate recovery method, which is applied to the above-mentioned steam pipeline condensate recovery system. When the electric control box recognizes that the flow rate of condensate in the drain pipe is lower than a preset speed threshold (1.2 m / s), the steam pipeline condensate recovery method is adopted. The steam pipeline condensate recovery method includes the following steps:

[0068] Step S110: During operation, condensed water flows down the drain pipe to the condensed water storage tank.

[0069] Step S120: Steam evaporated from the condensate storage tank rises to the steam pipe through the drainage pipe.

[0070] Step S120 includes:

[0071] Step S121: Detect the high water level gauge. When the condensed water reaches the high water level, open the drain valve for emergency drainage.

[0072] By detecting the high water level gauge, when the electric control box identifies that the condensed water detected by the high water level gauge has reached the high water level position, the drain valve is opened for emergency drainage.

[0073] Step S122: Detect the middle water level gauge. When the condensed water reaches the middle water level, the middle water level switch is closed, the heater is powered on, and the condensed water in the condensed water storage tank begins to heat and evaporate.

[0074] By detecting the middle water level gauge, when the electric control box identifies that the condensed water detected by the middle water level gauge reaches the middle water level position, the middle water level switch is controlled to close, the heater is powered on, and the condensed water in the condensed water storage tank begins to heat and evaporate.

[0075] Step S123, detecting the low water level gauge. When the condensed water drops below the lower water level position, the lower water level switch is disconnected, the heater is disconnected from the power supply, and the condensed water in the condensed water storage tank no longer evaporates.

[0076] By detecting the low water level gauge, when the electric control box identifies that the condensed water detected by the low water level gauge drops below the lower water level position, the lower water level switch is controlled to be disconnected, the power supply of the heater is disconnected, and the condensed water in the condensed water storage tank no longer evaporates.

[0077] Step S124 , starting the timing from when the heater is turned on, when the set first heating time is reached, the heater is directly turned off regardless of whether the middle water level is closed.

[0078] The electric control box controls the heater action, and the timing starts from when the heater is turned on. When the first heating time (e.g. 5400 / m s ), regardless of whether the water level is closed, the heater is directly disconnected.

[0079] Step S125, simultaneously detect whether the lower water level gauge is in a closed state. If it is in a closed state, the second heating time starts from the moment the heating stops. If the set second heating time is reached, the heater is powered on to continue heating. At the same time, the third heating time starts.

[0080] The electric control box detects whether the water level gauge is in the closed state. If it is in the closed state, the second heating time starts from the moment the heating stops. If the set second heating time (150s) is reached, the heater is powered on to continue heating. At the same time, the third heating time starts.

[0081] A second embodiment of the present invention relates to a steam pipeline condensate recovery method, which is applied to the above-mentioned steam pipeline condensate recovery system. When the electric control box recognizes that the flow rate of condensate in the drain pipe is higher than a preset speed threshold (1.2 m / s), the steam pipeline condensate recovery method is adopted. The steam pipeline condensate recovery method includes the following steps:

[0082] Step S210: During operation, condensed water flows down from the drain pipe to the condensed water storage tank.

[0083] Step S220: The steam evaporated from the condensate storage tank rises to the steam pipeline through the exhaust pipe.

[0084] Step S220 includes:

[0085] Step S221: Check the high water level gauge. When the condensed water reaches the high water level, open the drain valve for emergency drainage.

[0086] By detecting the high water level gauge, when the electric control box identifies that the condensed water detected by the high water level gauge has reached the high water level position, the drain valve is opened for emergency drainage.

[0087] Step S222: Detect the middle water level gauge. When the condensed water reaches the middle water level, the middle water level switch is closed, the heater is powered on, and the condensed water in the condensed water storage tank begins to heat and evaporate.

[0088] By detecting the middle water level gauge, when the electric control box identifies that the condensed water detected by the middle water level gauge reaches the middle water level position, the middle water level switch is controlled to close, the heater is powered on, and the condensed water in the condensed water storage tank begins to heat and evaporate.

[0089] Step S223, check the low water level gauge. When the condensed water drops below the lower water level, the lower water level switch is disconnected, the heater is disconnected from the power supply, and the condensed water in the condensed water storage tank no longer evaporates.

[0090] By detecting the low water level gauge, when the electric control box identifies that the condensed water detected by the low water level gauge drops below the lower water level position, the lower water level switch is controlled to be disconnected, the power supply of the heater is disconnected, and the condensed water in the condensed water storage tank no longer evaporates.

[0091] like Figures 1 to 8 As shown, the steam pipeline condensate recovery method and system provided in this embodiment have the following working principles:

[0092] The technical solution provided in this embodiment directly collects condensed water from the pipeline and then electrically heats it. The heated condensed water then returns to steam and is returned to the steam pipeline for continued use. This technical solution avoids the high cost of constructing pipelines for the condensed water (which accompanies the steam delivery pipeline) and also allows for more efficient energy recovery.

[0093] It's worth noting that according to the DL / T5054-2016 "Design Specifications for Steam-Water Pipelines in Thermal Power Plants," the diameter of the drain pipe for low-temperature, low-pressure steam must not be less than 38mm. In actual engineering design, the drain pipes for long-distance steam pipelines must not exceed 50m apart. This means that the existing steam pipeline already has a drain pipe. Our technology eliminates the need for external condensate discharge by simply installing a steam condensate recovery device on the existing drain pipe.

[0094] The steam pipeline condensate recovery system consists of a water inlet 10, a steam exhaust 30, a condensate storage tank 20, a heater 41, an electrical control box, a water level gauge 43, and a drain valve 52. The heater 41 is responsible for providing the heat required for heating. The water inlet 10 introduces condensate from the steam pipeline into the condensate storage tank. After heating, it becomes steam and returns to the steam pipeline 100 through the steam exhaust 30. The condensate storage tank 20 is equipped with three water level gauges: a low water level gauge, a mid-water level gauge, and a high water level gauge. The water level gauges are sensors that control when heating starts and stops. Heating starts when the low water level is reached; heating stops when the mid-water level is reached; and the drain valve opens when the high water level is reached to discharge excess condensate to ensure the safety of the steam pipeline. The electrical control box is an integrated and protective device for electrical equipment.

[0095] There are two ways to connect the steam pipeline condensate recovery device system to the original system. When the condensate flow rate in the drain pipe is lower than 1.2m / s, method 1 can be used. When it is higher than 1.2m / s, method 2 can be used. The specific connection method is as follows: Figure 5 and Figure 6 As shown:

[0096] Method 1 for accessing the original system:

[0097] Note: The exhaust and water inlet are in the same pipe. Whether the pipe is in heating or exhaust state is determined by whether the heater is heating.

[0098] Method 2 for accessing the original system:

[0099] Note: The exhaust and water inlet are two different pipes, responsible for the exhaust and condensed water entry respectively.

[0100] 1. Heating power calculation method

[0101] Different power recovery devices should be used for different pipelines. The condensate volume of the condensate recovery system must be accurately mastered. The formula for calculating the condensate volume of the steam pipeline is:

[0102]

[0103] Among them, m s is the condensed water volume (in kg / h), Q is the radiation heat transfer value obtained from the table (in W / m), L is the equivalent length of the pipe including flanges and joints (in m), f is the insulation coefficient obtained from the table, h fg is the enthalpy of vaporization of steam at pipeline pressure (in kJ / kg).

[0104] 2. The formula for calculating heat dissipation power (heating power) is:

[0105] HS=Q*L*f

[0106] Where HS is the heat dissipation power (in kW).

[0107] example:

[0108] Assume the steam in the pipeline is 188°C, 1.2 MPa, with a latent heat of vaporization of 1985.7 kJ / kg, a pipeline length of 100 m, a diameter of DN100, and an insulation thickness of 50 mm. The ambient temperature is 20°C.

[0109] 3. Calculate the amount of condensed water

[0110] 1) Calculate the temperature difference

[0111] 188-20=168℃

[0112] 2) Based on the temperature difference and pipe diameter, check the steel pipe radiation heat dissipation table, Q = 1200W / m.

[0113] 3) Assume that the air velocity is 0.

[0114] 4) Check the insulation coefficient table based on the thickness of the insulation layer and steam pressure, f=0.08.

[0115] 5) Calculate the heat dissipation as:

[0116] HS=1200*100*0.08

[0117] =9600W=9.6kW

[0118] 6) Calculate the amount of condensed water

[0119]

[0120] Radiant heat dissipation of uninsulated steel pipe exposed to air at 20℃

[0121]

[0122] The influence of ambient air flow on the heat dissipation of pipe surface

[0123] Air flow m / s Heat dissipation factor 0.00 1.0 0.50 1.0 1.00 1.3 2.00 1.7 2.50 1.8 3.00 2.0 4.00 2.3 6.00 2.9 8.00 3.5 10.00 4

[0124] Thermal insulation coefficient

[0125]

[0126]

[0127] Run method 1:

[0128] During operation, condensate flows down the drain pipe to the condensate storage tank, and steam evaporated from the condensate storage tank rises up the drain pipe to the steam pipe. Therefore, the drain pipe is responsible for both the downward flow of condensate and the upward flow of steam.

[0129] However, this situation cannot be carried out at the same time, that is, it cannot be both up and down at the same time, it can only be carried out in different time periods.

[0130] The automatic control system is designed to operate heating and heating (exhaust) in separate time periods. During the heating and evaporation process, the drain pipes facilitate steam upward movement. However, condensate generated in the steam pipes is temporarily unable to flow down and accumulates there. After the heating period, the drain pipes facilitate condensate downward movement, transferring the condensate from the steam pipes to the condensate storage tank.

[0131] In this way, in the continuous cycle of heating-pause-heating-pause, the condensed water in the steam pipe is continuously evaporated.

[0132] Automatic control logic:

[0133] The on / off of the heater is determined based on the detection of the low, medium and high water level states (liquid level below disconnection, liquid level below closing).

[0134] The specific judgment logic is as follows:

[0135] 1) Check the high water level gauge. When the condensate reaches this position, open the drain valve for emergency drainage.

[0136] 2) Check the middle water level gauge. When the condensed water reaches this position, the middle water level switch closes, the heater is powered on, and the condensed water in the condensed water storage tank begins to heat and evaporate.

[0137] During the heating and evaporation process, the steam in the condensate storage tank rises into the steam pipe through the drain pipe, and the water level in the condensate storage tank drops after the condensate evaporates.

[0138] 3) Check the water level gauge. When the condensed water drops below the lower water level, the lower water level switch is disconnected, the heater is disconnected from the power supply, and the condensed water in the condensed water storage tank no longer evaporates.

[0139] At this time, since the condensate is continuously generated in the steam transmission pipeline and still drops into the condensate storage tank through the drainage pipe, the water level in the condensate storage tank is constantly rising.

[0140] 4) Start timing from the time the heater is turned on. When time s is reached, the heater will be turned off directly regardless of whether the water level is closed.

[0141] Calculation method of heating time s:

[0142] 1. Calculation of condensed water volume

[0143]

[0144] 2. Calculate heating time

[0145] s=5400 / m s

[0146] s is the heating time (unit is s), m s is the amount of condensed water (unit: kg / h).

[0147] 5) When the heating time has expired, the water level gauge is checked to see if it is closed. If it is, the timer begins counting from the moment heating stops, with a 150-second pause. When the pause time has expired, the heater is turned on to resume heating, and the heater on timer begins.

[0148] Run method 2:

[0149] During operation, condensate drops from the drain pipe to the condensate storage tank, and steam evaporated from the condensate storage tank rises to the steam pipe through the exhaust pipe.

[0150] In automatic control, the heater is controlled by a water level gauge.

[0151] Automatic control logic:

[0152] The on / off of the heater is determined based on the detection of the low, medium and high water level states (liquid level below disconnection, liquid level below closing).

[0153] The specific judgment logic is as follows:

[0154] 1) Check the high water level gauge. When the condensate reaches this position, open the drain valve for emergency drainage.

[0155] 2) Check the middle water level gauge. When the condensed water reaches this position, the middle water level switch closes, the heater is powered on, and the condensed water in the condensed water storage tank begins to heat and evaporate.

[0156] 3) Check the water level gauge. When the condensed water drops below the lower water level, the lower water level switch is disconnected, the heater is disconnected from the power supply, and the condensed water in the condensed water storage tank no longer evaporates.

[0157] At this time, since the condensate is continuously generated in the steam transmission pipeline and still drops into the condensate storage tank through the drain pipe, the water level in the condensate storage tank is constantly rising.

[0158] example:

[0159] Continuing with the above example, assume the steam price is 180 yuan / t, 0.18 yuan / kg, and the electricity cost is 0.5 yuan / kW·h. The resulting condensate volume is 17.4 kg / h. In practice, since steam is used as the driving force for condensate discharge, steam is inevitably discharged along with it. In the above example, the measured steam discharge volume is 7.8 kg / h per hour.

[0160] 1) Calculate steam savings

[0161] (7.8+17.4)*0.18=4.536 yuan / h

[0162] 2) Calculate electricity consumption costs

[0163] As calculated in the previous case, the power consumption is 9.6kW, so the actual electricity cost is

[0164] 9.6*0.5=4.8 yuan / h

[0165] 3) The actual cost is 0.26 yuan / h.

[0166] in conclusion:

[0167] The operating cost is essentially offset by the steam cost savings, resulting in an extremely low cost. However, this equipment solves the impact of condensate discharge on production site safety and environmental protection, and has great practical value in actual production activities.

[0168] The present embodiment provides a method and system for recovering condensate from a steam pipe. Compared with the prior art, the condensate recovery system for a steam pipe is connected to the drain pipe on the steam pipe, and includes an introduction mechanism, a collection mechanism, a heating mechanism, and a steam exhaust mechanism. The introduction mechanism is used to introduce condensate from the drain pipe; the collection mechanism is used to collect condensate introduced by the introduction mechanism; the heating mechanism is used to heat the condensate collected by the collection mechanism into steam; and the steam exhaust mechanism is used to return the steam heated by the heating mechanism to the steam pipe. The method and system for recovering condensate from a steam pipe provided by the present embodiment is provided by adding a condensate recovery device to the original condensate drain pipe, and by means of electric heating, the condensate is restored to a steam state, so that the pipe no longer discharges condensate. The operating cost of this embodiment is basically offset by the steam cost saved, and the cost is extremely low; however, it solves the impact of condensate discharge on the safety and environmental protection of the production site, and has great practical value in actual production activities.

[0169] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the invention. Thus, the present invention is intended to include such changes and modifications as fall within the scope of the claims and their equivalents.

Claims

1. A steam pipeline condensate recovery system, characterized in that: The steam pipeline condensate recovery system is connected to the drainage pipe on the steam pipeline, and includes an introduction mechanism, a collection mechanism, a heating mechanism and a steam exhaust mechanism, wherein: The introduction mechanism is used to introduce condensed water into the drainage pipe; The collecting mechanism is connected to the introducing mechanism and is used to collect the condensed water introduced by the introducing mechanism; The heating mechanism is provided near the collecting mechanism and is used to heat the condensed water collected by the collecting mechanism into steam; The steam exhaust mechanism is connected to the collecting mechanism and is used to return the steam heated by the heating mechanism to the steam pipeline; The heating mechanism includes a heater (41), an electric control box and a water level gauge (43), wherein the water level gauge (43) includes a low water level gauge, a middle water level gauge and a high water level gauge, and the low water level gauge, the middle water level gauge and the high water level gauge are arranged in descending order at the low water level position, the middle water level position and the high water level position in the condensed water storage tank (20); the electric control box is electrically connected to the low water level gauge through the lower water level switch, the electric control box is electrically connected to the middle water level gauge through the middle water level switch, and the electric control box is electrically connected to the high water level gauge through the upper water level switch. The bottom of the condensed water storage tank (20) is provided with a drain pipe (51), the drain pipe (51) is connected to the condensed water storage tank (20), a drain valve (52) is provided on the drain pipe (51), and the drain valve (52) is electrically connected to the electric control box. The top of the condensed water storage tank (20) is provided with a drain pipe (61), the drain pipe (61) is connected to the condensed water storage tank (20), a drain valve (62) is provided on the drain pipe (61), and the drain valve (62) is electrically connected to the electric control box. By detecting the high water level When the electric control box identifies that the condensed water detected by the high water level gauge has reached the high water level position, the drain valve is opened for emergency drainage; by detecting the middle water level gauge, when the electric control box identifies that the condensed water detected by the middle water level gauge has reached the middle water level position, the middle water level switch is controlled to be closed, the heater is powered on, and the condensed water in the condensed water storage tank begins to be heated and evaporated; by detecting the low water level gauge, when the electric control box identifies that the condensed water detected by the low water level gauge drops below the lower water level position, the lower water level switch is controlled to be disconnected, the heater is powered off, and the condensed water in the condensed water storage tank no longer evaporates; and the timing starts from the time the heater is turned on. When the set first heating time is reached, the heater is directly disconnected regardless of whether the middle water level is closed; at the same time, whether the lower water level gauge is in a closed state. If it is in a closed state, the second heating time starts from the moment the heating stops. If the set second heating time is reached, the heater is powered on to continue heating, and at the same time, the third heating time starts.

2. The steam pipeline condensate recovery system according to claim 1, characterized in that: The introduction mechanism comprises a water inlet (10), which is connected to the drainage pipe and is used to introduce condensed water in the drainage pipe.

3. The steam pipeline condensate recovery system according to claim 2, characterized in that: The collecting mechanism comprises a condensed water storage tank (20), which is connected to the water inlet (10) and is used to collect the condensed water introduced through the water inlet (10).

4. The steam pipeline condensate recovery system according to claim 3, characterized in that: The steam exhaust mechanism comprises a steam exhaust port (30), which is respectively connected to the condensed water storage tank (20) and the steam exhaust pipe (31), and is used to return the steam heated by the heating mechanism to the steam pipeline through the steam exhaust pipe (31).

5. The steam pipeline condensate recovery system according to claim 4, characterized in that: The heater (41) is electrically connected to the electric control box. The heater (41) is arranged in the condensed water storage tank (20). The electric control box is arranged close to the outer wall of the condensed water storage tank (20). The heater (41) is used to heat the condensed water collected in the condensed water storage tank (20) into steam.

6. A method for recovering condensed water from a steam pipeline, characterized in that: The method is applied to the steam pipeline condensate recovery system according to any one of claims 1 to 5, comprising the following steps: During operation, condensate water flows down the drain pipe to the condensate storage tank; The steam evaporated from the condensate storage tank rises to the steam pipe through the drain pipe; The step of steam evaporated from the condensate storage tank rising to the steam pipe through the drainage pipe includes: Check the high water level gauge. When the condensate reaches the high water level, open the drain valve for emergency drainage. Detect the middle water level gauge. When the condensed water reaches the middle water level, the middle water level switch is closed, the heater is powered on, and the condensed water in the condensed water storage tank begins to heat and evaporate. Detect the low water level gauge. When the condensed water drops below the lower water level, the lower water level switch is disconnected, the heater is disconnected from the power supply, and the condensed water in the condensed water storage tank no longer evaporates. The timing starts from the moment the heater is turned on. When the set first heating time is reached, the heater will be turned off directly regardless of whether the water level is closed or not. At the same time, the water level gauge is detected to see if it is in a closed state. If it is closed, the second heating time starts from the moment the heating stops. If the set second heating time is reached, the heater is powered on to continue heating. At the same time, the third heating time starts.

7. A method for recovering condensed water from a steam pipeline, characterized in that: The method is applied to the steam pipeline condensate recovery system according to any one of claims 1 to 5, comprising the following steps: During operation, condensate drops from the drain pipe to the condensate storage tank; The steam evaporated from the condensate storage tank rises to the steam pipe through the exhaust pipe; The step of steam evaporated from the condensate storage tank rising to the steam pipeline through the exhaust pipe includes: Check the high water level gauge. When the condensate reaches the high water level, open the drain valve for emergency drainage. Detect the middle water level gauge. When the condensed water reaches the middle water level, the middle water level switch is closed, the heater is powered on, and the condensed water in the condensed water storage tank begins to heat and evaporate. Check the low water level gauge. When the condensed water drops below the lower water level, the lower water level switch is disconnected, the heater is disconnected from the power supply, and the condensed water in the condensed water storage tank no longer evaporates.

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