An energy-saving control device for low-parameter steam waste heat recovery and utilization

Abstract

The present invention relates to the field of energy-saving control technology, and specifically to an energy-saving control device for recovering waste heat from low-parameter steam. A water collecting component is provided at the lower end of a cooling coil, and the lower end of the water collecting component is connected to a drain pipe extending to the outside of a waste heat recovery box, and a flow meter is provided on the drain pipe. The output end of the cooling coil is externally connected to an exhaust pipe, and a temperature sensor is provided on the exhaust pipe. The temperature sensor and the flow meter are electrically connected to a controller, and the beneficial effects are as follows: a control air valve is provided between a water inlet and an air inlet device, so as to achieve a reaction to the air intake amount and synchronously adjust the water inlet flow rate, and the sensor is used to detect the temperature of the air flow after discharge and the water flow rate after condensation to judge the efficiency of waste heat recovery, thereby achieving precise control of the water flow rate and the air intake flow rate in the waste heat recovery, and achieving the purpose of efficiently recovering the waste heat of steam.

Description

Technical Field

[0001] The present invention relates to the technical field of energy-saving control, and in particular to an energy-saving control device for recovering waste heat of low-parameter steam. Background Art

[0002] In the prior art, when steam is used to drive a steam turbine, the utilization rate of the steam is low. Therefore, in order to fully utilize the energy, a heat recovery device is usually provided to further recover the heat in the steam to fully utilize the energy.

[0003] Existing common heat recovery devices usually adopt the circulating water supply method of cooling coils. CN201410511896.X discloses a coal drying water vapor heat recovery device and a working method, wherein a coal drying water vapor heat recovery device comprises a silo, a throttle valve, a compressor, a condenser, a vacuum machine and a condensation water pool; the silo and the condenser are both provided with a preheating pipe; a heat-conducting medium is sealed in the preheating pipe; one end of the preheating pipe arranged in the silo is connected to the condenser through a throttle valve, and the other end is connected to the condenser through a compressor; the condenser is connected to the condensation water pool through a pipeline; the silo is provided with a plurality of air permeable pipes for filtering and transporting water vapor, and the plurality of air permeable pipes are connected to the condenser through a main pipeline.

[0004] However, for the drive of the steam turbine device, its steam utilization efficiency is higher than that of other equipment. Therefore, the inverted residual steam temperature is low and the airflow is small, which belongs to low-parameter waste heat recovery. However, the less the residue and the lower the temperature, the lower the recovery efficiency, making it difficult to fully recover energy. Therefore, it is necessary to adjust the energy recovery equipment in real time. Summary of the invention

[0005] The object of the present invention is to provide an energy-saving control device for recovering waste heat from low-parameter steam to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An energy-saving control device for recovering waste heat from low-parameter steam, the energy-saving control device comprising a waste heat recovery box, an air inlet bag, a water inlet box and a controller, a horizontally placed cooling coil is arranged in the waste heat recovery box, the input end of the cooling coil is connected to the air inlet bag, the water inlet box is connected to the inner cavity of the waste heat recovery box, a piston and a pneumatic expansion component for driving the piston to rise and fall are arranged in the water inlet box and the air inlet bag, control air valves electrically connected to the controller are arranged, a water collecting component is arranged at the lower end of the cooling coil, a drain pipe extending to the outside of the waste heat recovery box is connected to the lower end of the water collecting component, a flow meter is arranged on the drain pipe, the output end of the cooling coil is externally connected to an exhaust pipe, a temperature sensor is arranged on the exhaust pipe, and the temperature sensor and the flow meter are both electrically connected to the controller.

[0008] Preferably, the inner cavity of the waste heat recovery box is configured as a water inlet cavity, a water outlet and a water inlet pipe connected to the water inlet box are provided on one side of the water inlet cavity, an inner lining plate is provided in the water inlet cavity to separate the water inlet pipe port and the water outlet, a drainage channel is formed between the inner lining plate and the inner wall of the water inlet cavity, and the water outlet is connected to the drainage channel.

[0009] Preferably, the water collecting assembly includes a partition and a U-shaped tube, the partition is fixed on the inner wall of the lower end of the water inlet cavity, a plurality of groups of through-connecting tubes facing the lower end of the cooling coil are arranged on the partition, an interface connected to the through-connecting tube is arranged at the bending position of the lower end of the cooling coil, a drain pipe is arranged at the lower end of the partition, and the drain pipe is connected to the through-connecting tube through a U-shaped tube.

[0010] Preferably, one end of the U-shaped tube is connected to the lower end of the connecting pipe, and the other end of the U-shaped tube is located at the lower end of the partition and a hollow partition ball is provided at the end. One side of the hollow partition ball is vertically connected to an overflow pipe, and the other end of the overflow pipe is connected to the drain pipe.

[0011] Preferably, an intermediate tube penetrating the water inlet cavity is provided in the middle of the inner lining plate, the cooling coil is sleeved on the intermediate tube, and a gap is left between the outer wall of the cooling coil and the outer wall of the intermediate tube, and a plurality of groups of linearly spaced side panels are provided on the front and rear sides of the inner lining plate, one end of the side panel is fixed on the inner wall of the inner lining plate, and the other end of the side panel extends to the outer wall of the cooling coil, and a gap is left between the outer wall of the cooling coil.

[0012] Preferably, a display screen is provided on the controller, the water inlet tank and the air inlet bag are connected via a connecting pipe, and the control air valve is installed on the connecting pipe.

[0013] Preferably, the pneumatic expansion assembly includes a folding airbag, a pair of T-shaped rods are provided at the upper end of the piston, a spring is sleeved on the T-shaped rod, the upper end of the spring is against the upper cross plate of the T-shaped rod, the lower end of the spring is against the upper outer wall of the water inlet tank, and the folding airbag is pressed between the piston and the upper inner wall of the water inlet tank.

[0014] Preferably, a pair of ear seats are provided on the middle inner wall of the water inlet box, the piston is located above the ear seats, and the outer diameter of the piston is greater than the width between adjacent ear seats.

[0015] Preferably, a return pipe connected to the exhaust pipe is provided at one end of the intermediate pipe, a switching valve is provided between the exhaust pipe and the return pipe, a second exhaust port is provided on the switching valve, and a first exhaust port is provided at the other end of the intermediate pipe.

[0016] Preferably, an air inlet pipe connected to steam is provided at one end of the air inlet bag, and a drain outlet is provided at the outer end of the drain pipe.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention realizes the reaction of air intake volume by setting a control air valve between the water inlet and air inlet equipment, and simultaneously achieves the adjustment of the water inlet flow rate. The efficiency of waste heat recovery is judged by detecting the temperature of the air flow after discharge and the water flow rate after condensation using a sensor, thereby achieving precise control of the water flow rate and the air intake flow rate in the waste heat recovery, and achieving the purpose of efficiently recovering the waste heat of steam. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the device of the present invention;

[0020] Figure 2 A three-dimensional diagram of the connection between the air inlet bag and the water inlet tank of the present invention;

[0021] Figure 3 It is a schematic diagram of the air inlet bag and water inlet box structure of the present invention;

[0022] Figure 4 It is a front view of the device of the present invention;

[0023] Figure 5 It is a schematic diagram of the three-dimensional structure of the partition of the present invention;

[0024] Figure 6 It is a schematic diagram of the three-dimensional structure of the inner lining plate of the present invention.

[0025] In the figure: 1. waste heat recovery box; 2. partition; 3. water inlet cavity; 4. controller; 5. display screen; 6. air inlet bag; 7. water inlet box; 8. connecting pipe; 9. control valve; 10. air inlet pipe; 11. cooling coil; 12. return pipe; 13. temperature sensor; 14. drain pipe; 15. U-shaped pipe; 16. drain outlet; 17. flow meter; 18. water inlet pipe; 19. lining plate; 20. intermediate pipe; 21. first exhaust port; 22. drainage channel; 23. water outlet; 24. piston; 25. folding air bag; 26. side plate; 27. T-shaped rod; 28. spring; 29. ​​ear seat; 30. exhaust pipe; 31. switching valve; 32. second exhaust port; 33. overflow pipe; 34. hollow partition ball; 35. through-connecting pipe. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] See also Figures 1 to 6 , the present invention provides a technical solution:

[0028] Embodiment 1: An energy-saving control device for recovering waste heat from low-parameter steam, the energy-saving control device comprising a waste heat recovery box 1, an air inlet bag 6, a water inlet box 7 and a controller 4. A horizontally placed cooling coil 11 is provided in the waste heat recovery box 1, the input end of the cooling coil 11 is connected to the air inlet bag 6, one end of the air inlet bag 6 is provided with an air inlet pipe 10 connected to the steam, the inner cavity of the waste heat recovery box 1 is provided as a water inlet cavity 3, one side of the water inlet cavity 3 is provided with a water outlet 23 and a water inlet pipe 18 connected to the water inlet box 7.

[0029] By setting up a cooling coil 11 connected to the air inlet bag 6, the used steam is introduced therein, so that the steam flows in the cooling coil 11. During the flow, the circulating water is used to make the steam contact with the water flow of the circulating water to achieve heat transfer, thereby achieving the purpose of waste heat recovery.

[0030] The water inlet tank 7 is connected to the inner cavity of the waste heat recovery tank 1 , and a piston 24 and a pneumatic expansion component for driving the piston 24 to rise and fall are arranged in the water inlet tank 7 , and a control air valve 9 electrically connected to the controller 4 is arranged between the water inlet tank 7 and the air inlet bag 6 .

[0031] When the steam intake flow rate is fast, the steam airflow will flow faster in the cooling coil 11, thereby reducing the contact time with the circulating water flow and reducing the waste heat recovery efficiency. At the same time, the air intake bag 6 expands, which poses a safety risk. Therefore, by setting the control valve 9 and the pneumatic expansion component to cooperate, when the steam intake is fast, the internal pressure of the air intake bag 6 increases. At this time, the controller 4 drives the control valve 9 to open, thereby transmitting the steam to the pneumatic expansion component, so as to achieve the purpose of reducing the internal pressure of the air intake bag 6 and reducing the airflow rate. At the same time, the pneumatic expansion component is expanded to drive the piston 24 to descend. As the piston 24 descends, the internal pressure of the water inlet tank 7 increases, driving the circulating water flow to flow rapidly and improving the heat transfer efficiency. Such two-way regulation can achieve the purpose of improving the waste heat recovery efficiency.

[0032] A water collecting assembly is provided at the lower end of the cooling coil 11, and the lower end of the water collecting assembly is connected to a drain pipe 14 extending to the outside of the waste heat recovery box 1, and a flow meter 17 is provided on the drain pipe 14. The output end of the cooling coil 11 is externally connected to an exhaust pipe 30, and a temperature sensor 13 is provided on the exhaust pipe 30. The temperature sensor 13 and the flow meter 17 are both electrically connected to the controller 4.

[0033] By setting up a water collecting component, the water droplets formed by the condensation of steam during the heat transfer process are collected and discharged centrally. By setting up a flow meter 17, the flow rate of the condensed water flow can be monitored. By setting up a temperature sensor 13 on the exhaust pipe 30, the temperature of the exhaust air flow can be detected. By detecting the flow rate and temperature, the efficiency of waste heat recovery can be reflected.

[0034] When the flow meter 17 detects a decrease in flow, it indicates that the condensation speed is reduced. Therefore, there are two situations: 1. The steam intake volume is reduced, resulting in a decrease in condensed water; 2. The circulating water flow rate is slow, resulting in a decrease in condensation efficiency;

[0035] When the temperature sensor 13 detects that the exhaust temperature rises, it means that the waste heat recovery efficiency is reduced. There are two situations: 1. The circulating water flow rate is slow; 2. The steam flow rate is too fast and there is no time for timely condensation and cooling.

[0036] According to the detected data, the control valve 9 and the pneumatic expansion assembly are adjusted to achieve the purpose of accurately controlling the water flow rate and the steam flow rate, thereby realizing efficient waste heat recovery.

[0037] Example 2: Based on Example 1, an inner lining plate 19 is provided in the water inlet cavity 3 to separate the port of the water inlet pipe 18 and the water outlet 23, a drainage channel 22 is formed between the inner lining plate 19 and the inner wall of the water inlet cavity 3, and the water outlet 23 is connected to the drainage channel 22.

[0038] By providing the inner lining plate 19, cold water enters along the water inlet pipe 18 and flows transversely along the water inlet cavity 3. After fully contacting the cooling coil 11, it flows in the reverse direction and is discharged, thereby increasing the contact time and improving the efficiency of heat transfer.

[0039] The water collecting assembly includes a partition 2 and a U-shaped tube 15. The partition 2 is fixed on the inner wall of the lower end of the water inlet cavity 3. The partition 2 is provided with multiple groups of through-connecting tubes 35 facing the lower end of the cooling coil 11. The lower end bending position of the cooling coil 11 is provided with an interface connected to the through-connecting tube 35. The drain pipe 14 is arranged at the lower end of the partition 2. The drain pipe 14 is connected to the through-connecting tube 35 through the U-shaped tube 15. One end of the U-shaped tube 15 is connected to the lower end of the through-connecting tube 35. The other end of the U-shaped tube 15 is located at the lower end of the partition 2 and a hollow partition ball 34 is provided at the end. One side of the hollow partition ball 34 is vertically connected to the overflow pipe 33, and the other end of the overflow pipe 33 is connected to the drain pipe 14.

[0040] By providing a U-shaped tube 15 and a hollow baffle ball 34, the condensed water flow is gathered in the U-shaped tube 15, forming a liquid seal for the lower end of the cooling coil 11, preventing steam from being discharged along the water collecting component. Since the internal pressure of the steam in the cooling coil 11 is high, the liquid level of the water flow on the other side of the U-shaped tube 15 is easily caused to rise, so the hollow baffle ball 34 is designed. When the liquid level of the water flow rises in the hollow baffle ball 34, as the inner diameter increases, the water flow fills the inner cavity of the hollow baffle ball 34, thereby increasing the gravity of the water flow, forming a balance with the internal pressure of the steam on the other side, and ensuring that the lower end of the U-shaped tube 15 is filled with water.

[0041] An intermediate pipe 20 penetrating the water inlet cavity 3 is arranged in the middle of the inner lining plate 19, and the cooling coil 11 is sleeved on the intermediate pipe 20, and a gap is left between the outer wall of the cooling coil 11 and the outer wall of the intermediate pipe 20. A plurality of groups of linearly spaced side panels 26 are arranged on the front and rear sides of the inner lining plate 19, and one end of the side panel 26 is fixed on the inner wall of the inner lining plate 19, and the other end of the side panel 26 extends to the outer wall of the cooling coil 11, and a gap is left between the outer wall of the cooling coil 11.

[0042] By providing the intermediate pipe 20 and multiple sets of side plates 26 , the cooling water entering from the lower layer can only flow upward along the gap between the cooling coil 11 and the side plates 26 , further increasing the contact time and area between the water flow and the cooling coil 11 .

[0043] Embodiment 3: On the basis of Embodiment 2, a display screen 5 is provided on the controller 4, the water inlet tank 7 and the air inlet bag 6 are connected by a connecting pipe 8, and the control air valve 9 is installed on the connecting pipe 8, the pneumatic expansion assembly includes a folding air bag 25, a pair of T-shaped rods 27 are provided at the upper end of the piston 24, a spring 28 is sleeved on the T-shaped rod 27, the upper end of the spring 28 abuts against the upper end cross plate of the T-shaped rod 27, and the lower end of the spring 28 abuts against the upper end outer wall of the water inlet tank 7, and the folding air bag 25 is pressed between the piston 24 and the upper end inner wall of the water inlet tank 7.

[0044] By setting the connection between the T-shaped rod 27, the spring 28 and the piston 24, the elastic vertical installation of the piston 24 is realized, so that under the drive of the pneumatic expansion component, the spring 28 is stretched and the piston 24 elastically slides down. When the pneumatic expansion component is depressurized, the piston 24 automatically rises and resets under the reset elastic force of the spring 28.

[0045] A pair of ear seats 29 are provided on the middle inner wall of the water inlet box 7 , and the piston 24 is located above the ear seats 29 . The outer diameter of the piston 24 is greater than the width between adjacent ear seats 29 .

[0046] The ear seat 29 is provided to limit the descending height of the piston 24, thereby preventing excessive squeezing of the water tank 7, which would cause excessive water pressure and leakage.

[0047] A return pipe 12 connected to the exhaust pipe 30 is provided at one end of the intermediate pipe 20, a switching valve 31 is provided between the exhaust pipe 30 and the return pipe 12, a second exhaust port 32 is provided on the switching valve 31, a first exhaust port 21 is provided at the other end of the intermediate pipe 20, and a drain port 16 is provided at the outer end of the drain pipe 14.

[0048] By setting the switching valve 31, the airflow discharged after condensation can be adjusted. When the steam intake is too large, the recovery efficiency of the cooling coil 11 cannot meet the requirement of full recovery. At this time, the switching valve 31 is used to guide the discharged airflow into the intermediate pipe 20 to achieve another heat transfer with the water flow, so as to achieve full waste heat recovery, so that the waste heat recovery box 1 is adapted to the recovery of variable and unstable residual steam.

[0049] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An energy-saving control device for recycling waste heat of low-parameter steam, the energy-saving control device comprising a waste heat recovery box (1), an air inlet bag (6), a water inlet box (7) and a controller (4), wherein a horizontally placed cooling coil (11) is arranged in the waste heat recovery box (1), an input end of the cooling coil (11) is connected to the air inlet bag (6), and the water inlet box (7) is connected to the inner cavity of the waste heat recovery box (1), characterized in that: The water inlet box (7) is provided with a piston (24) and a pneumatic expansion component for driving the piston (24) to rise and fall; the water inlet box (7) and the air inlet bag (6) are provided with a control air valve (9) electrically connected to the controller (4); the lower end of the cooling coil (11) is provided with a water collection component; the lower end of the water collection component is connected to a drainage pipe (14) extending to the outside of the waste heat recovery box (1); the drainage pipe (14) is provided with a flow meter (17); the output end of the cooling coil (11) is externally connected to an exhaust pipe (30); the exhaust pipe (30) is provided with a temperature sensor (13); the temperature sensor (13) and the flow meter (17) are both electrically connected to the controller (4); The inner cavity of the waste heat recovery box (1) is configured as a water inlet inner cavity (3), a water outlet (23) and a water inlet pipe (18) connected to the water inlet box (7) are provided on one side of the water inlet inner cavity (3), an inner lining plate (19) is provided in the water inlet inner cavity (3) to separate the port of the water inlet pipe (18) and the water outlet (23), a drainage channel (22) is formed between the inner lining plate (19) and the inner wall of the water inlet inner cavity (3), and the water outlet (23) is connected to the drainage channel (22); The pneumatic expansion assembly comprises a folding airbag (25), a pair of T-shaped rods (27) are provided at the upper end of the piston (24), a spring (28) is sleeved on the T-shaped rod (27), the upper end of the spring (28) abuts against the upper end cross plate of the T-shaped rod (27), the lower end of the spring (28) abuts against the upper end outer wall of the water inlet tank (7), the folding airbag (25) is pressed between the piston (24) and the upper end inner wall of the water inlet tank (7), the controller (4) is provided with a display screen (5), the water inlet tank (7) and the air inlet bag (6) are connected via a connecting pipe (8), and a control air valve (9) is installed on the connecting pipe (8), the controller (4) drives the control air valve (9) to open, thereby transmitting steam to the pneumatic expansion assembly, so as to reduce the internal pressure of the air inlet bag (6) and reduce the air flow rate, and simultaneously expand the pneumatic expansion assembly and drive the piston (24) to descend.

2. The energy-saving control device for low-parameter steam waste heat recovery and utilization according to claim 1, characterized in that: The water collecting assembly comprises a baffle (2) and a U-shaped tube (15); the baffle (2) is fixed to the inner wall of the lower end of the water inlet cavity (3); a plurality of groups of through-connecting tubes (35) facing the lower end of the cooling coil (11) are arranged on the baffle (2); an interface connected to the through-connecting tube (35) is arranged at a bent position at the lower end of the cooling coil (11); a drainage tube (14) is arranged at the lower end of the baffle (2); and the drainage tube (14) and the through-connecting tube (35) are connected via the U-shaped tube (15).

3. The energy-saving control device for low-parameter steam waste heat recovery and utilization according to claim 2 is characterized in that: One end of the U-shaped tube (15) is connected to the lower end of the connecting tube (35), and the other end of the U-shaped tube (15) is located at the lower end of the partition plate (2) and is provided with a hollow spacer ball (34) at the end. An overflow pipe (33) is vertically connected to one side of the hollow spacer ball (34), and the other end of the overflow pipe (33) is connected to the drain pipe (14).

4. The energy-saving control device for low-parameter steam waste heat recovery and utilization according to claim 3 is characterized in that: An intermediate pipe (20) penetrating the water inlet cavity (3) is arranged in the middle of the inner lining plate (19); the cooling coil (11) is sleeved on the intermediate pipe (20), and a gap is left between the outer wall of the cooling coil (11) and the outer wall of the intermediate pipe (20); a plurality of groups of linearly spaced side plates (26) are arranged on the front and rear sides of the inner lining plate (19); one end of the side plate (26) is fixed on the inner wall of the inner lining plate (19), and the other end of the side plate (26) extends to the outer wall of the cooling coil (11), and a gap is left between the side plate and the outer wall of the cooling coil (11).

5. The energy-saving control device for low-parameter steam waste heat recovery and utilization according to claim 4 is characterized in that: A pair of ear seats (29) are provided on the middle inner wall of the water inlet box (7), the piston (24) is located above the ear seats (29), and the outer diameter of the piston (24) is greater than the width between adjacent ear seats (29).

6. The energy-saving control device for low-parameter steam waste heat recovery and utilization according to claim 5, characterized in that: A return pipe (12) communicating with an exhaust pipe (30) is provided at one end of the intermediate pipe (20); a switching valve (31) is provided between the exhaust pipe (30) and the return pipe (12); a second exhaust port (32) is provided on the switching valve (31); and a first exhaust port (21) is provided at the other end of the intermediate pipe (20).

7. The energy-saving control device for low-parameter steam waste heat recovery and utilization according to claim 6 is characterized in that: An air intake pipe (10) connected to steam is provided at one end of the air intake bag (6), and a water discharge port (16) is provided at the outer end of the water discharge pipe (14).

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