Steam-water heat exchange unit

Abstract

The utility model discloses a steam-water heat exchange unit which comprises a steam pipeline, a cooling water pipeline, a tubular heat exchanger, a detachable plate heat exchanger and a water tank. A pressure sensor, a temperature sensor and a second electric valve are sequentially connected between the steam inlet connecting pipe and the tubular heat exchanger; the cooling water pipeline comprises a cooling water inlet pipeline connected to a cooling water inlet of the detachable plate heat exchanger, the cooling water inlet pipeline is connected with the water tank through a make-up pump, and a water inlet pipeline of the make-up pump is connected with an electromagnetic valve drainage recycling pipeline and a safety valve drainage recycling pipeline in parallel at the same time. The performance advantages of the tubular heat exchanger and the plate heat exchanger are combined, secondary heat exchange is carried out by the system through multi-stage heat exchange of the tubular heat exchanger and the plate heat exchanger, heat in high-temperature steam is further recycled, and the energy utilization efficiency is high.

Description

Technical Field

[0001] The utility model relates to the technical field of heat exchange equipment, in particular to a steam-water heat exchange unit. Background Art

[0002] Partition heat exchangers have been widely used in industries such as petrochemicals, metallurgy, food, heating and electricity. There are a large number of steam heat sources in power plants and chemical plants. In order to avoid heat source waste and make full use of energy, steam can be used for heating and heating domestic water, etc. When using steam-water heat exchangers to achieve steam and water heat exchange, there will be a large amount of steam condensate. It was found at the user site that a large amount of steam condensate was directly discharged without recycling, resulting in waste; water hammer will occur in the steam system, and conventional heat exchangers do not consider solutions to this problem; at the same time, it is often seen that users do not recycle the water released by the safety valve and solenoid valve at the site, resulting in waste of resources and safety hazards; in addition, the shell and tube heat exchanger can withstand high-temperature and high-pressure steam, while the detachable plate heat exchanger has high heat exchange efficiency and is easy to clean. By switching and combining the two in the steam-water heat exchange system, safer and more efficient heat exchange can be achieved.

[0003] The technical solution proposed by the utility model creatively combines a shell and tube heat exchanger, a detachable plate heat exchanger, condensate recovery and a pipeline drain valve group to form a steam-water heat exchange system, which solves the problem that conventional heat exchange units fail to fully utilize condensate recovery and cannot provide sufficient make-up water on site; at the same time, a single shell and tube heat exchanger cannot achieve temperature cross heat exchange (i.e., the outlet temperature of the cold side medium is greater than the outlet temperature of the hot measurement), system water hammer phenomenon, and the collection and reuse of condensate in the steam pipeline, condensate in the heat exchanger and the pressure relief water of the safety valve water recovery pipeline and the solenoid valve water recovery pipeline. Utility Model Content

[0004] The purpose of the utility model is to provide a steam-water heat exchange unit to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0006] A steam-water heat exchange unit, comprising a steam pipeline, a cooling water pipeline, a shell-and-tube heat exchanger, a detachable plate heat exchanger and a water tank, wherein the steam pipeline comprises a steam inlet pipe connected to the steam inlet of the shell-and-tube heat exchanger, a pressure sensor, a temperature sensor and a second electric valve are connected in sequence between the steam inlet pipe and the shell-and-tube heat exchanger, another branch is provided on the steam inlet pipe between the temperature sensor and the second electric valve and is connected to the steam inlet pipe of the detachable plate heat exchanger through the first electric valve, and the steam outlet pipe of the shell-and-tube heat exchanger is also connected to the steam outlet pipe of the detachable plate heat exchanger through a check valve The steam inlet and the steam outlet of the detachable plate heat exchanger are connected to the water tank; the cooling water pipeline includes a cooling water inlet pipeline connected to the cooling water inlet of the detachable plate heat exchanger, and a fourth electric valve is provided on the cooling water outlet pipeline of the detachable plate heat exchanger, and a third electric valve is provided on the cooling water inlet pipeline of the shell and tube heat exchanger; the cooling water inlet pipeline is connected to the water tank through a make-up water pump, and a solenoid valve water recovery pipeline and a safety valve water recovery pipeline are connected in parallel on the water inlet pipeline of the make-up water pump, and a safety valve is provided on the safety valve water recovery pipeline; a solenoid valve is provided on the solenoid valve water recovery pipeline.

[0007] Preferably, the steam inlet connecting pipe is connected to a water tank, and a steam trap group is provided between the steam inlet connecting pipe and the water tank.

[0008] Preferably, a control cabinet is provided on the top of the steam-water heat exchange unit, and the pressure sensor, the temperature sensor, the first electric valve, the second electric valve, the third electric valve, and the fourth electric valve are connected to the control cabinet through control cables.

[0009] The working process of the utility model is:

[0010] The steam medium enters the shell and tube heat exchanger through the pipeline for primary heat exchange, and then passes through the plate heat exchanger for secondary heat exchange. The thermal measurement electric valve, temperature sensor, pressure sensor, steam trap group, water tank, etc. are connected through pipelines, and the electric valve, temperature sensor, and pressure sensor are connected to the control cabinet; the water side electric valve, safety valve, solenoid valve, water tank, etc. are connected through pipelines, and the electric valve and solenoid valve are connected to the control cabinet.

[0011] When steam is transported in the pipeline, part of it will condense into condensate. If the condensate is not discharged in time, the heat exchange capacity of the heat exchanger will be reduced and even water hammer will occur. For this reason, the heat exchange system adds a steam trap group before the steam enters the heat exchanger pipeline to discharge the condensate in time and recycle the condensate into the water tank for reuse. Before the steam enters the heat exchanger, there are temperature sensors and pressure sensors to feed back the detection data to the control cabinet system and compare it with the set value to determine whether to use only the plate heat exchanger or the plate heat exchanger. The plate heat exchanger and the shell and tube heat exchanger are connected in series. The maximum temperature resistance of the plate heat exchanger is 180℃. When the sensor data is greater than 180℃, the bypass solenoid valve is closed and the steam enters the shell and tube heat exchanger for heat exchange first, and then enters the plate heat exchanger. In this way, the temperature in the shell and tube heat exchanger is reduced to below 180℃ before entering the plate heat exchanger for heat exchange, which is safer and improves the service life of the plate heat exchanger product; when the steam inlet temperature is detected to be lower than 180℃, the bypass solenoid valve is opened. At this time, the steam does not enter the shell and tube heat exchanger, but passes through the bypass. Directly use plate heat exchangers to achieve more efficient heat exchangers. When problems occur in the shell and tube heat exchanger, it will not affect the normal operation of the system, and a stable and efficient heat exchanger can be achieved. Heat is only exchanged in the plate heat exchanger, which is easy to clean and maintain in the later stage and has low cost. In addition, the plate heat exchanger can be used alone or in series with the shell and tube heat exchanger to achieve temperature cross-heat exchange (i.e., the outlet temperature of the cold side medium is greater than the outlet temperature of the hot side medium); by switching and combining the shell and tube heat exchanger and the plate heat exchanger, the system's adaptability to multiple working conditions is improved, and high efficiency and safety are achieved. Full heat exchange reduces maintenance costs; finally, the condensate enters the water tank; the electric valve on the water side must be linked with the thermal measurement electric valve; the safety valve and the solenoid valve are connected in parallel to stabilize the system pressure, and the pressure relief water of the safety and solenoid valves is collected in the water tank. The condensate in the pipeline, the condensate in the heat exchanger, and the pressure relief water of the safety valve and the solenoid valve are all gathered in the water tank. As the water for replenishment in the system, only water needs to be injected into the water tank during the first replenishment. The water replenishment in the later system can be met by relying on the condensate, which improves the utilization rate of water resources and solves the problem of insufficient replenishment on site.

[0012] The beneficial effects of the utility model are:

[0013] (1) The heat exchange unit system of the utility model combines the performance advantages of a shell-and-tube heat exchanger and a plate heat exchanger, and realizes safe and efficient operation of the plate heat exchanger and the shell-and-tube heat exchanger by switching on and off different electric valves in the system. The system performs secondary heat exchange by utilizing multi-stage heat exchange of the shell-and-tube heat exchanger and the plate heat exchanger, and further recovers and reuses the heat in the high-temperature steam, thereby achieving high energy utilization efficiency. At the same time, the shell-and-tube heat exchanger and the plate heat exchanger can be flexibly switched by the first electric valve and the second electric valve to adapt to different working conditions.

[0014] (2) In the heat exchanger system of the utility model, a steam trap group is arranged between the steam inlet pipe and the water tank, and a safety valve and a solenoid valve working in parallel are arranged on the cooling water inlet pipeline to prevent the system from overpressure and ensure the smooth operation of the system.

[0015] (3) The water tank in the heat exchanger system of the utility model realizes the purpose of collecting and reusing the condensate in the steam pipeline, the condensate in the heat exchanger, and the pressure relief water in the safety valve water recovery pipeline and the solenoid valve water recovery pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the workflow of the utility model;

[0017] Among them: 1. Steam inlet pipe; 2. Pressure sensor; 3. Temperature sensor; 4. First electric valve; 5. Second electric valve; 6. Shell and tube heat exchanger; 7. Check valve; 8. Removable plate heat exchanger; 9. Steam trap group; 10. Water tank; 11. Make-up water pump; 12. Solenoid valve; 13. Solenoid valve water recovery pipeline; 14. Safety valve; 15. Safety valve water recovery pipeline; 16. Cooling water inlet pipeline; 17. Third electric valve; 18. Fourth electric valve; 19. Control cabinet. DETAILED DESCRIPTION

[0018] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0019] like Figure 1A steam-water heat exchange unit shown in the figure comprises a steam pipeline, a cooling water pipeline, a shell-and-tube heat exchanger 6, a detachable plate heat exchanger 8 and a water tank 10. The steam pipeline comprises a steam inlet pipe 1 connected to the steam inlet on the shell-and-tube heat exchanger 6. A pressure sensor 2, a temperature sensor 3 and a second electric valve 5 are connected in sequence between the steam inlet pipe 1 and the shell-and-tube heat exchanger 6. Another branch is provided on the steam inlet pipe 1 between the temperature sensor 3 and the second electric valve 5 and is connected to the steam inlet pipe of the detachable plate heat exchanger 8 through the first electric valve 4. The steam outlet pipe of the shell-and-tube heat exchanger 6 is also connected to the steam inlet of the detachable plate heat exchanger 8 through a check valve 7. The steam outlet of the detachable plate heat exchanger 8 is connected to the water tank 10; the cooling water pipeline includes a cooling water inlet pipeline 16 connected to the cooling water inlet of the detachable plate heat exchanger 8, and a fourth electric valve 18 is provided on the cooling water outlet pipeline of the detachable plate heat exchanger 8, and a third electric valve 17 is provided on the cooling water inlet pipeline of the tube-in-tube heat exchanger 6; the cooling water inlet pipeline 16 is connected to the water tank 10 through a water supply pump 11, and a solenoid valve drain recovery pipeline 13 and a safety valve drain recovery pipeline 15 are connected in parallel on the water inlet pipeline of the water supply pump 11, and a safety valve 14 is provided on the safety valve drain recovery pipeline 15; a solenoid valve 12 is provided on the solenoid valve drain recovery pipeline 13. At the same time, the steam inlet pipe 1 is connected to the water tank 10, and a steam trap group 9 is provided between the steam inlet pipe 1 and the water tank 10.

[0020] A control cabinet 19 is provided on the top of the steam-water heat exchange unit, and the pressure sensor 2, the temperature sensor 3, the first electric valve 4, the second electric valve 5, the third electric valve 17, and the fourth electric valve 18 are connected to the control cabinet 19 through control cables.

[0021] The working process of the utility model is:

[0022] Steam enters the heat exchange unit system through the steam inlet pipe 1, and the condensate in the steam enters the water tank 10 through the steam trap group 9. When the steam passes through the pressure sensor 2 and the temperature sensor 3, the detected temperature data is fed back to the control cabinet 19 and compared with the set value. When the value is greater than 180°C, the second electric valve 5 is opened and the electric valve 4 is closed. The steam enters the shell and tube heat exchanger 6 for heat exchange and then enters the detachable plate heat exchanger 8 for heat exchange. When the value is less than 180°C, the second electric valve 5 is closed and the first electric valve 4 is opened. At this time, the steam does not pass through the shell and tube heat exchanger 6 and directly exchanges heat in the detachable plate heat exchanger 8. At the same time, a stop valve is set at the outlet of the shell and tube heat exchanger 6. Return valve 7 prevents steam from entering the shell and tube heat exchanger 6, and finally the steam condenses into the water tank; the fourth electric valve 18 on the water side and the first electric valve 4 on the steam side are kept in linkage, and the third electric valve 17 on the water side and the second electric valve 5 on the steam side are kept in linkage; the safety valve 14 and the solenoid valve 12 are connected in parallel to stabilize the system pressure, and the pressure relief water of the safety valve 14 and the solenoid valve 12 is collected into the water tank 10 through the solenoid valve water relief recovery pipeline 13 and the safety valve water relief recovery pipeline 15. The condensate in the pipeline, the condensate in the heat exchanger and the pressure relief water of the safety valve and the solenoid valve are all gathered in the water tank 10 as the water for replenishing water in the system. It is only necessary to inject water into the water tank 10 during the first replenishment.

[0023] The utility model combines the performance advantages of a shell and tube heat exchanger and a plate heat exchanger, and realizes safe and efficient operation of the plate heat exchanger and the shell and tube heat exchanger by switching different electric valves in the system. The system performs secondary heat exchange by utilizing multi-stage heat exchange of the shell and tube heat exchanger and the plate heat exchanger, and further recovers and reuses the heat in the high-temperature steam, thereby achieving high energy utilization efficiency. At the same time, the shell and tube heat exchanger and the plate heat exchanger are flexibly switched by the first electric valve and the second electric valve to adapt to different working conditions.

[0024] The above are only preferred examples of the present invention. It should be pointed out that for ordinary technicians in this field, under the technical inspiration provided by the present invention, as common knowledge in the mechanical field, other equivalent variations and improvements can be made, which should also be regarded as the protection scope of the present invention.

Claims

1. A steam-water heat exchange unit, characterized in that: The invention comprises a steam pipeline, a cooling water pipeline, a shell-and-tube heat exchanger (6), a detachable plate heat exchanger (8) and a water tank (10), wherein the steam pipeline comprises a steam inlet pipe (1) connected to the steam inlet of the shell-and-tube heat exchanger (6), a pressure sensor (2), a temperature sensor (3) and a second electric valve (5) are connected in sequence between the steam inlet pipe (1) and the shell-and-tube heat exchanger (6), another branch is provided on the steam inlet pipe (1) between the temperature sensor (3) and the second electric valve (5) and is connected to the steam inlet pipe of the detachable plate heat exchanger (8) through a first electric valve (4), the steam outlet pipe of the shell-and-tube heat exchanger (6) is also connected to the steam inlet of the detachable plate heat exchanger (8) through a check valve (7), and the steam outlet of the detachable plate heat exchanger (8) is connected to the water tank (10); The cooling water pipeline comprises a cooling water inlet pipeline (16) connected to the cooling water inlet of the detachable plate heat exchanger (8), a fourth electric valve (18) is provided on the cooling water outlet pipeline of the detachable plate heat exchanger (8), and a third electric valve (17) is provided on the cooling water inlet pipeline of the shell and tube heat exchanger (6); The cooling water inlet pipeline (16) is connected to the water tank (10) via a water supply pump (11); a solenoid valve water recovery pipeline (13) and a safety valve water recovery pipeline (15) are connected in parallel to the water supply pipeline of the water supply pump (11); a safety valve (14) is provided on the safety valve water recovery pipeline (15); and a solenoid valve (12) is provided on the solenoid valve water recovery pipeline (13).

2. A steam-water heat exchange unit according to claim 1, characterized in that: The steam inlet pipe (1) is connected to the water tank (10), and a steam trap group (9) is provided between the steam inlet pipe (1) and the water tank (10).

3. A steam-water heat exchange unit according to claim 1 or 2, characterized in that: A control cabinet (19) is provided on the top of the steam-water heat exchange unit, and the pressure sensor (2), the temperature sensor (3), the first electric valve (4), the second electric valve (5), the third electric valve (17), and the fourth electric valve (18) are connected to the control cabinet (19) via control cables.

Images