Waste heat recycling device for power plant

Abstract

The utility model relates to the technical field of boiler devices, and particularly discloses a waste heat recycling device for a power plant. The device comprises a water pump, a plate heat exchanger, a first normal-temperature desalted water supply pipe, a first high-temperature desalted water outlet pipe, a second high-temperature desalted water outlet pipe, a second normal-temperature desalted water supply pipe, a bypass desalted water supply pipe, a deaerator, a desalted water tank, an agglutinator, an uplink pipeline, a downlink pipeline, an external desalted water supply pipe and a deaerator water inlet pipe. According to the waste heat recycling and reusing device for the power plant, the heat exchanger and the desalted water pipeline are reasonably arranged, reasonable access points are selected, and waste heat generated in the links of oil refining, hydrogen production and the like is absorbed through boiler water of the power plant, so that the boiler water is heated, the coal consumption of the boiler is reduced, the coal burning amount of the boiler is reduced, and carbon emission is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of boiler devices, and specifically discloses a waste heat recovery and reuse device for power plants. Background Art

[0002] With the development of society and the vigorous promotion of ecological civilization, various industries are paying more attention to the production environment and developing heat recovery projects. During boiler operation, desalted water is generally gradually heated from room temperature to superheated steam at a certain pressure. In the integrated refining unit, hydroisomerization and diesel hydrorefining processes generate some waste heat. This heat is often forced to exchange heat through the circulating water cooling tower and then discharged into the atmosphere, wasting both heat energy and a large amount of circulating water. This is not conducive to energy conservation and emission reduction for enterprises, and brings huge economic losses to enterprises.

[0003] In an integrated refining unit, a large amount of high-temperature waste heat is generated during the hydroisomerization, diesel hydrorefining or hydrogen production process. This waste heat is often forced to cool through a circulating water tower pool after heat exchange in a heat exchanger, and then discharged to the atmosphere. Most of the heat energy is discharged, accompanied by a large amount of waste water.

[0004] Therefore, it is necessary to propose a device for recovering and reusing waste heat in the oil refining process to solve the above technical problems. Utility Model Content

[0005] The purpose of the utility model is to provide a method for utilizing the boiler water of a self-contained power plant in an integrated refining and chemical plant to absorb waste heat generated in the oil refining and hydrogen production process, thereby heating the boiler water, reducing boiler coal consumption, reducing boiler coal combustion, and reducing carbon emissions.

[0006] The technical solutions adopted in this utility model are as follows:

[0007] A waste heat recovery and reuse device for a power plant, comprising a water pump, a plate heat exchanger, a first normal-temperature desalted water supply pipe 2-1, a first high-temperature desalted water outlet pipe 2-2, a second high-temperature desalted water outlet pipe 3, a second normal-temperature desalted water supply pipe 4, a branch desalted water supply pipe 5, a deaerator, a desalted water tank 8, a condenser 9, an upstream and downstream pipeline 10, an external desalted water supply pipe 11, and a deaerator inlet pipe 12;

[0008] The water pump is connected to the inlet of the plate heat exchanger through the first normal-temperature desalted water supply pipe 2-1, and the outlet of the plate heat exchanger is connected to the external hot water main pipe through the first high-temperature desalted water outlet pipe 2-2; the water pump is connected to the desalted water tank 8 through the second normal-temperature desalted water supply pipe 4; the first high-temperature desalted water outlet pipe 2-2 branches off into a second high-temperature desalted water outlet pipe 3, which is connected to the middle of the second normal-temperature desalted water supply pipe 4; a valve is provided in the middle of the second high-temperature desalted water outlet pipe 3;

[0009] The external desalted water is connected to the condenser 9 via an external desalted water supply pipe 11; the external desalted water supply pipe 11 branches off into a deaerator water inlet pipe 12 connected to the deaerator, and an upstream and downstream pipeline 10 is connected to the second normal temperature desalted water supply pipe 4, with the upstream and downstream pipelines 10 branching off near one end of the external desalted water and the deaerator water inlet pipe 12 branching off near one end of the condenser 9; valves are provided on the upstream and downstream pipelines 10;

[0010] One end of the side branch desalted water supply pipe 5 is connected in front of the upstream and downstream pipelines 10 branch outlets of the second normal temperature desalted water supply pipe 4, and the other end is connected between the deaerator inlet pipe 12 branch outlet and the upstream and downstream pipelines 10 branch outlets of the external desalted water supply pipe 11; a valve is provided in the middle of the side branch desalted water supply pipe 5.

[0011] Preferably, two plate heat exchangers are provided, namely a first plate heat exchanger 1-1 and a second plate heat exchanger 1-2, which are connected in parallel between the first normal temperature desalted water supply pipe 2-1 and the first high temperature desalted water outlet pipe 2-2.

[0012] Furthermore, the first plate heat exchanger 1 - 1 and the second plate heat exchanger 1 - 2 are both provided with side branches and valves before the inlet and after the outlet for the circulation of water when no heat exchange is taking place.

[0013] Preferably, a valve group is provided between the deaerator and the deaerator water inlet pipe 12 for control.

[0014] Furthermore, the deaerator and valve group are each provided in two groups, including a first deaerator 7-1, a second deaerator 7-2, a first valve group 6-1, and a second valve group 6-2, which are respectively connected in parallel to the end of the deaerator water inlet pipe 12.

[0015] Preferably, the external desalted water supply pipe 11 is provided with two routes, which eventually converge in front of the condenser 9; valves are provided on both routes before the convergence.

[0016] Furthermore, the deaerator water inlet pipe 12 and the branch desalted water supply pipe 5 are both connected only to the same water supply pipe before the external desalted water supply pipe 11 converges.

[0017] Furthermore, the up-down pipeline 10 is provided with two branches, which are respectively connected to two external desalted water supply pipes 11 .

[0018] Preferably, the pipeline in the device is made of 304 steel with a wall thickness of not less than 6.0 mm.

[0019] Preferably, the desalted water delivery pressure of the water pump is controlled to be 0.7-1.0 MPa.

[0020] Beneficial effects achieved by this utility model:

[0021] The utility model is a waste heat recovery and reuse device for power plants. After reasonably equipping heat exchangers and desalted water pipelines and selecting reasonable access points, it uses the water from the self-provided power plant boiler to absorb the waste heat generated in the oil refining and hydrogen production processes, thereby heating the boiler water, reducing boiler coal consumption, reducing boiler coal burning, and reducing carbon emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of Example 1 of the present utility model. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention more clear and distinct, the present invention is further described in detail in conjunction with the following embodiments. It should be noted that the present invention is not limited to the following embodiments.

[0024] Example 1

[0025] like Figure 1 As shown, a waste heat recovery and reuse device for a power plant includes a water pump, a plate heat exchanger, a first normal-temperature desalted water supply pipe 2-1, a first high-temperature desalted water outlet pipe 2-2, a second high-temperature desalted water outlet pipe 3, a second normal-temperature desalted water supply pipe 4, a branch desalted water supply pipe 5, a deaerator, a desalted water tank 8, a condenser 9, an upstream and downstream pipeline 10, an external desalted water supply pipe 11, and a deaerator inlet pipe 12; the plate heat exchanger absorbs heat from the boiler system; the deaerator utilizes heat from the high-temperature desalted water; and the desalted water in the condenser 9 is mixed with a coagulant.

[0026] The water pump is connected to the inlet of the plate heat exchanger through the first normal-temperature desalted water supply pipe 2-1, and the outlet of the plate heat exchanger is connected to the external hot water main pipe through the first high-temperature desalted water outlet pipe 2-2; the water pump is connected to the desalted water tank 8 through the second normal-temperature desalted water supply pipe 4; the first high-temperature desalted water outlet pipe 2-2 branches off into a second high-temperature desalted water outlet pipe 3, which is connected to the middle of the second normal-temperature desalted water supply pipe 4; a valve is provided in the middle of the second high-temperature desalted water outlet pipe 3;

[0027] The external desalted water is connected to the condenser 9 via an external desalted water supply pipe 11; the external desalted water supply pipe 11 branches off into a deaerator water inlet pipe 12 connected to the deaerator, and an upstream and downstream pipeline 10 is connected to the second normal temperature desalted water supply pipe 4, with the upstream and downstream pipelines 10 branching off near one end of the external desalted water and the deaerator water inlet pipe 12 branching off near one end of the condenser 9; valves are provided on the upstream and downstream pipelines 10;

[0028] One end of the side branch desalted water supply pipe 5 is connected in front of the upstream and downstream pipelines 10 branch outlets of the second normal temperature desalted water supply pipe 4, and the other end is connected between the deaerator inlet pipe 12 branch outlet and the upstream and downstream pipelines 10 branch outlets of the external desalted water supply pipe 11; a valve is provided in the middle of the side branch desalted water supply pipe 5.

[0029] Two plate heat exchangers are provided: a first plate heat exchanger 1-1 and a second plate heat exchanger 1-2, connected in parallel between a first normal-temperature desalted water supply pipe 2-1 and a first high-temperature desalted water outlet pipe 2-2. Bypasses and valves are provided before and after the inlets and outlets of the first and second plate heat exchangers 1-1, 1-2 to facilitate water circulation when not exchanging heat.

[0030] A valve group is provided between the deaerator and the deaerator water inlet pipe 12 for control. The deaerator and valve group are each provided in two groups, including a first deaerator 7-1, a second deaerator 7-2, a first valve group 6-1, and a second valve group 6-2, which are respectively connected in parallel to the ends of the deaerator water inlet pipe 12.

[0031] The external desalinated water supply pipe 11 has two routes, which ultimately converge before the condenser 9. Both routes are equipped with valves. The deaerator inlet pipe 12 and the branch desalinated water supply pipe 5 are both connected to only one of the same routes before the external desalinated water supply pipe 11 converges.

[0032] The up-down pipeline 10 is provided with two branches, which are respectively connected to two external desalted water supply pipes 11 .

[0033] The pipe material of the device is 304 steel with a wall thickness of not less than 6.0 mm. The desalted water delivery pressure of the water pump is controlled to be 0.7-1.0 MPa.

[0034] Once the boiler system is operational, the desalted water used in some heat exchange equipment (accounting for approximately 2.0% of the load rate) can be replaced entirely with high-temperature desalted water. This desalted water, after heat exchange with refining waste heat, can be heated from room temperature to 80°C. Preliminary calculations show that a single 220t / h CFB boiler with a rated evaporation capacity, operating at a load rate between 75% and 85%, can save 3,600tce of standard coal per month annually, a significant improvement.

Claims

1. A waste heat recovery and reuse device for a power plant, characterized in that: It includes a water pump, a plate heat exchanger, a first normal-temperature desalted water supply pipe (2-1), a first high-temperature desalted water outlet pipe (2-2), a second high-temperature desalted water outlet pipe (3), a second normal-temperature desalted water supply pipe (4), a branch desalted water supply pipe (5), a deaerator, a desalted water tank (8), a condenser (9), an upstream and downstream pipeline (10), an external desalted water supply pipe (11), and a deaerator inlet pipe (12); The water pump is connected to the inlet of the plate heat exchanger through a first normal-temperature desalted water supply pipe (2-1), and the outlet of the plate heat exchanger is connected to the external hot water main pipe through a first high-temperature desalted water outlet pipe (2-2); the water pump is connected to the desalted water tank (8) through a second normal-temperature desalted water supply pipe (4); a second high-temperature desalted water outlet pipe (3) branches off from the first high-temperature desalted water outlet pipe (2-2) and is connected to the middle of the second normal-temperature desalted water supply pipe (4); a valve is provided in the middle of the second high-temperature desalted water outlet pipe (3); The external desalted water is connected to the condenser (9) through the external desalted water supply pipe (11); the external desalted water supply pipe (11) branches out a deaerator water inlet pipe (12) connected to the deaerator, and the up-down pipeline (10) is connected to the second normal temperature desalted water supply pipe (4), the up-down pipeline (10) branch is close to one end of the external desalted water, and the deaerator water inlet pipe (12) branch is close to one end of the condenser (9); valves are provided on the up-down pipeline (10); One end of the side branch desalted water supply pipe (5) is connected to the front of the branch of the up-down pipeline (10) of the second normal temperature desalted water supply pipe (4), and the other end is connected between the branch of the deaerator water inlet pipe (12) and the branch of the up-down pipeline (10) of the external desalted water supply pipe (11); a valve is provided in the middle of the side branch desalted water supply pipe (5).

2. The waste heat recovery and reuse device for power plants according to claim 1, characterized in that: Two plate heat exchangers are provided, namely a first plate heat exchanger (1-1) and a second plate heat exchanger (1-2), which are connected in parallel between a first normal-temperature desalted water supply pipe (2-1) and a first high-temperature desalted water outlet pipe (2-2).

3. The waste heat recovery and reuse device for power plants according to claim 2, characterized in that: Both the first plate heat exchanger (1-1) and the second plate heat exchanger (1-2) are provided with side branches and valves before the inlet and after the outlet for water circulation when no heat exchange is taking place.

4. The waste heat recovery and reuse device for power plants according to claim 1, characterized in that: A valve group is provided between the deaerator and the deaerator water inlet pipe (12) for control.

5. The waste heat recovery and reuse device for power plants according to claim 4, characterized in that: The deaerator and valve group are both provided in two groups, including a first deaerator (7-1), a second deaerator (7-2), a first valve group (6-1), and a second valve group (6-2), which are respectively connected in parallel to the ends of the deaerator water inlet pipes (12).

6. The waste heat recovery and reuse device for power plants according to claim 1, characterized in that: The external desalted water supply pipe (11) is provided with two routes, which eventually converge in front of the condenser (9); valves are provided on both routes before the convergence.

7. The waste heat recovery and reuse device for power plants according to claim 6, characterized in that: The deaerator water inlet pipe (12) and the branch desalted water supply pipe (5) are only connected to the same water supply pipe before the external desalted water supply pipe (11) converges.

8. The waste heat recovery and reuse device for power plants according to claim 7, characterized in that: The up-down pipeline (10) is provided with two branches, which are respectively connected to two external desalted water supply pipes (11).

9. The waste heat recovery and reuse device for power plants according to claim 1, characterized in that: The pipeline in the device is made of 304 steel with a wall thickness of not less than 6.0 mm.

10. The waste heat recovery and reuse device for power plants according to claim 1, characterized in that: The desalted water delivery pressure of the water pump is controlled to be 0.7-1.0 MPa.

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