Steam condensate waste heat recovery device

Abstract

This utility model discloses a steam condensate waste heat recovery device. The device includes a condensate storage tank, with a condensate inlet pipe connecting to plant equipment and a condensate outlet pipe connecting to a boiler. The top of the storage tank is connected to the condenser shell side via a steam pipe, and the condenser shell side outlet returns to the storage tank via a condensate return pipe. The two ends of the condenser tube side are respectively connected to a demineralized water supply pipe and a demineralized water delivery pipe. The demineralized water delivery pipe connects to the storage tank and has a demineralized water buffer tank and an electrically controlled valve in the middle. A liquid level sensor is installed on the inner wall of the storage tank, which is linked to the electrically controlled valve. The steam pipe and condensate return pipe are respectively equipped with backflushing liquid inlet and outlet pipes. A silencer is installed on the condenser, and a delivery pump and sampling pipe are installed on the condensate outlet pipe. This utility model, using the above structure, can efficiently recover vented steam and waste heat, reduce water and energy waste, achieve automatic liquid level control, improve system stability, and reduce maintenance costs. It is suitable for industrial steam systems in chemical, metallurgical, and other industries.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, specifically a waste heat recovery device for steam condensate. Background Technology

[0002] In the chemical production field, steam is widely used as an important heat carrier in processes such as heating, drying, and reaction. To achieve energy recycling, factories typically recover the steam condensate generated by steam-using equipment to a condensate storage tank, and then use a transfer pump to transport the condensate to a waste heat boiler as makeup water. This reduces the amount of fresh demineralized water needed and lowers boiler heating energy consumption. This process constitutes the basic steam condensate recovery system.

[0003] However, existing steam condensate recovery systems have the following prominent problems in actual operation: During the steam-using equipment and condensate transportation process, due to factors such as system pressure fluctuations and inadequate pipeline sealing, some steam may enter the condensate storage tank along with the condensate, or be directly vented during the tank venting process. This vented steam not only carries a large amount of latent heat and sensible heat, but also contains recoverable liquid water. Existing systems typically discharge it directly into the atmosphere, resulting in insufficient water recovery and waste of waste heat.

[0004] Due to losses from steam venting and pipeline leaks, the amount of condensate recovered by the condensate storage tank is insufficient to meet the makeup water requirements of the waste heat boiler, necessitating a continuous replenishment of fresh demineralized water. In the existing system, ambient temperature demineralized water is directly injected into the condensate storage tank. This causes a sharp drop in the temperature of the condensate inside the tank, requiring the boiler to consume more fuel to reheat the mixed makeup water to its boiling point. Furthermore, the significant temperature difference between the ambient temperature demineralized water and the high-temperature condensate can easily induce thermal stress on the inner wall of the storage tank, potentially affecting its service life over long-term operation. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide a steam condensate waste heat recovery device that can improve water resource recovery rate and waste heat utilization rate, reduce boiler energy consumption, and at the same time ensure the stability and continuity of system operation.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a steam condensate waste heat recovery device, including a condensate storage tank, a condensate inlet pipe and a condensate outlet pipe on the condensate storage tank, a steam pipe on the condensate storage tank, the steam pipe being connected to a condenser, a condensate return pipe on the condenser, and the condensate return pipe being connected back to the condensate storage tank.

[0007] In a preferred embodiment, the condensate inlet pipe is connected to the plant equipment and receives the condensate generated by the equipment, while the condensate outlet pipe is connected to the boiler as boiler makeup water.

[0008] In a preferred embodiment, the steam pipe and the condensate return pipe are connected to both ends of the shell side of the condenser; The condenser is equipped with a demineralized water supply pipe and a demineralized water delivery pipe at both ends of the tube side, and the demineralized water delivery pipe is also connected to the condensate storage tank.

[0009] In a preferred embodiment, the condensate outlet pipe is equipped with a delivery pump and a sampling pipe, and the sampling pipe is equipped with a sampling valve.

[0010] In a preferred embodiment, a demineralized water delivery pipe is provided with a demineralized water buffer tank, and an electrically controlled valve is provided on the demineralized water delivery pipe between the demineralized water buffer tank and the condensate storage tank.

[0011] In a preferred embodiment, the condensate storage tank is equipped with a liquid level sensor, and the liquid level sensor and the electrically controlled valve are connected to the same control module.

[0012] In a preferred embodiment, the steam pipe is provided with a backwash liquid inlet pipe, which is connected to the steam pipe as a branch pipe, and a backwash input valve is provided on the backwash liquid inlet pipe. The condensate return pipe is equipped with a backflushing liquid outlet pipe, which is connected to the condensate return pipe as a branch pipe. The backflushing liquid outlet pipe is equipped with a backflushing liquid outlet valve.

[0013] In a preferred embodiment, the condenser is further provided with a silencer.

[0014] The steam condensate waste heat recovery device provided by this utility model, by adopting the above-described structure, has the following beneficial effects: (1) The device can introduce the steam that was originally vented directly into the condenser, and after condensation, it flows back to the condensate storage tank to avoid the loss of water resources carried by the steam. At the same time, the waste heat of the steam is used to heat the demineralized water to reduce the temperature difference between the demineralized water and the high temperature condensate in the storage tank. This reduces the impact of the sudden drop in the temperature of the storage tank and reduces the energy consumption required for subsequent boiler heating, thus realizing the dual recovery and utilization of water resources and waste heat. (2) Through the linkage between the liquid level sensor and the electric control valve, the device can accurately control the liquid level of the condensate storage tank in real time, avoiding the overflow or supply interruption problems that are easy to occur when manually replenishing water, and ensuring a continuous and stable water supply to the boiler. (3) The backwashing section extends the equipment maintenance interval and enables convenient cleaning of scale on condenser pipes, maintaining heat exchange efficiency and comprehensively improving the system's operational stability. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] In the diagram: 1. Condensate storage tank; 2. Condensate inlet pipe; 3. Condensate outlet pipe; 4. Transfer pump; 5. Sampling pipe; 6. Sampling valve; 7. Steam pipe; 8. Condenser; 9. Condensate return pipe; 10. Demineralized water makeup pipe; 11. Demineralized water transfer pipe; 12. Demineralized water buffer tank; 13. Electrically controlled valve; 14. Liquid level sensor; 15. Backwash liquid inlet pipe; 16. Backwash liquid outlet pipe; 17. Backwash input valve; 18. Backwash output valve; 19. Silencer. Detailed Implementation

[0017] like Figure 1 In the present invention, a waste heat recovery device for steam condensate includes a condensate storage tank 1, wherein the condensate storage tank 1 is provided with a condensate inlet pipe 2 and a condensate outlet pipe 3, and the condensate storage tank 1 is also provided with a steam pipe 7, which is connected to a condenser 8. The condenser 8 is provided with a condensate return pipe 9, which is connected back to the condensate storage tank 1.

[0018] In a preferred embodiment, the condensate inlet pipe 2 is connected to the plant equipment and receives the condensate generated by the equipment, while the condensate outlet pipe 3 is connected to the boiler as boiler makeup water.

[0019] In a preferred embodiment, the steam pipe 7 and the condensate return pipe 9 are connected to both ends of the shell side of the condenser 8; The condenser 8 is provided with a demineralized water supply pipe 10 and a demineralized water delivery pipe 11 at both ends of the tube side, and the demineralized water delivery pipe 11 is also connected to the condensate storage tank 1.

[0020] In a preferred embodiment, the condensate outlet pipe 3 is equipped with a delivery pump 4 and a sampling pipe 5, and the sampling pipe 5 is equipped with a sampling valve 6.

[0021] In a preferred embodiment, a demineralized water conveying pipe 11 is provided with a demineralized water buffer tank 12, and an electrically controlled valve 13 is provided on the demineralized water conveying pipe 11 between the demineralized water buffer tank 12 and the condensate storage tank 1.

[0022] In a preferred embodiment, the condensate storage tank 1 is equipped with a liquid level sensor 14, and the liquid level sensor 14 and the electric control valve 13 are connected to the same control module.

[0023] In a preferred embodiment, the steam pipe 7 is provided with a backwash liquid inlet pipe 15, which is connected to the steam pipe 7 as a branch pipe, and a backwash input valve 17 is provided on the backwash liquid inlet pipe 15. The condensate return pipe 9 is provided with a backflushing liquid outlet pipe 16, which is connected to the condensate return pipe 9 as a branch pipe. The backflushing liquid outlet pipe 16 is provided with a backflushing liquid outlet pipe 16 and a backflushing output valve 18.

[0024] In a preferred embodiment, the condenser 8 is further provided with a muffler 19.

[0025] The operation process of the steam condensate waste heat recovery device disclosed in this utility model is as follows: First, the high-temperature condensate (approximately 80°C) generated by the steam-using equipment in the plant enters the condensate storage tank 1 through the condensate inlet pipe 2. When the liquid level in the storage tank reaches the liquid level value set by the liquid level sensor 14 (approximately 50% of the total volume of the storage tank), the transfer pump 4 on the condensate outlet pipe 3 is started to transport the condensate to the waste heat boiler as makeup water. During the transportation process, the sampling valve 6 can be opened periodically to extract condensate samples to test the water quality (such as pH value and conductivity) to ensure that the water quality meets the boiler makeup water standards.

[0026] Steam generated by pressure fluctuations in the condensate storage tank 1 enters the shell side of the condenser 8 through the top steam pipe 7. At the same time, the valve on the demineralized water makeup pipe 10 is opened, allowing room temperature demineralized water (about 25°C) to enter the tube side of the condenser 8. The steam and demineralized water exchange heat in the condenser, and the steam condenses into liquid water (temperature about 40°C), which flows back to the condensate storage tank 1 through the condensate return pipe 9. After absorbing heat, the temperature of the demineralized water rises to 60°C, and it enters the demineralized water buffer tank 12 through the demineralized water delivery pipe 11. The buffer tank can eliminate pressure fluctuations during the demineralized water delivery process. Then, it is slowly injected into the condensate storage tank 1 through the electrically controlled valve 13 to avoid direct impact and mixing between the high temperature condensate and the room temperature demineralized water.

[0027] The liquid level sensor 14 monitors the liquid level in the condensate storage tank 1 in real time. When the liquid level is low (about 30% of the total volume of the storage tank), the sensor sends a signal to the PLC control module, and the control module drives the solenoid valve 13 to open to replenish demineralized water. When the liquid level rises to a high level (about 70% of the total volume of the storage tank), the solenoid valve 13 automatically closes, realizing unattended control of the liquid level.

[0028] After the device has been running continuously for 3 months, close the shut-off valves on the steam pipe 7 and the condensate return pipe 9, open the backwash input valve 17 and the backwash output valve 18, and introduce a weak acid cleaning solution (such as citric acid solution) into the backwash inlet pipe 15. The cleaning solution flows through the shell side of the condenser 8, dissolves the scale on the inner wall of the pipe, and is discharged from the backwash outlet pipe 16. After cleaning, rinse with clean water for 20 minutes and then resume normal operation.

Claims

1. A steam condensate waste heat recovery device, comprising a condensate storage tank (1), wherein the condensate storage tank (1) is provided with a condensate inlet pipe (2) and a condensate outlet pipe (3), characterized in that: The condensate storage tank (1) is also provided with a steam pipe (7), which is connected to the condenser (8). The condenser (8) is provided with a condensate return pipe (9), which is connected back to the condensate storage tank (1).

2. The steam condensate waste heat recovery device according to claim 1, characterized in that: The condensate inlet pipe (2) is connected to the plant equipment and receives the condensate generated by the equipment, while the condensate outlet pipe (3) is connected to the boiler as boiler makeup water.

3. The steam condensate waste heat recovery device according to claim 1, characterized in that: The steam pipe (7) and the condensate return pipe (9) are connected to both ends of the shell side of the condenser (8); The condenser (8) has a demineralized water supply pipe (10) and a demineralized water delivery pipe (11) at both ends of the tube side, and the demineralized water delivery pipe (11) is also connected to the condensate storage tank (1).

4. The steam condensate waste heat recovery device according to claim 1, characterized in that: The condensate outlet pipe (3) is equipped with a delivery pump (4) and a sampling pipe (5), and the sampling pipe (5) is equipped with a sampling valve (6).

5. The steam condensate waste heat recovery device according to claim 3, characterized in that: The demineralized water delivery pipe (11) is equipped with a demineralized water buffer tank (12), and an electric control valve (13) is provided on the demineralized water delivery pipe (11) between the demineralized water buffer tank (12) and the condensate storage tank (1).

6. The steam condensate waste heat recovery device according to claim 5, characterized in that: The condensate storage tank (1) is equipped with a liquid level sensor (14), and the liquid level sensor (14) and the electric control valve (13) are connected to the same control module.

7. The steam condensate waste heat recovery device according to claim 1, characterized in that: The steam pipe (7) is provided with a backwash liquid inlet pipe (15), which is connected to the steam pipe (7) as a branch pipe. The backwash liquid inlet pipe (15) is provided with a backwash input valve (17). The condensate return pipe (9) is provided with a backflushing liquid outlet pipe (16), which is connected to the condensate return pipe (9) as a branch pipe. The backflushing liquid outlet pipe (16) is provided with a backflushing liquid outlet pipe (16) and a backflushing output valve (18) is provided on the backflushing liquid outlet pipe (16).

8. The steam condensate waste heat recovery device according to claim 1, characterized in that: The condenser (8) is also equipped with a silencer (19).

Images