Medium-pressure heat supply system of waste heat boiler
By introducing pressure matchers and cooling water regulation into the medium-pressure heating system of the waste heat boiler, the problem of high-pressure steam extraction affecting the output and high heat consumption of the steam engine is solved, and efficient steam utilization and low heat consumption heating are achieved.
Patent Information
- Application Number
- CN202510503486.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2025-08-12
AI Technical Summary
In the existing waste heat boiler medium pressure heating system, high-pressure steam extraction is more likely to affect the output of the steam engine and the combined cycle heat consumption is high.
By introducing a pressure matcher into the system, the cold re-steam is mixed with the high-pressure main steam and dilated the pressure, the high-pressure main steam is used as the power source to achieve the boost of the cold re-steam, and the steam temperature is adjusted by reducing the temperature of the medium-pressure heating parameters to reduce the high-pressure steam extraction volume and improve the steam utilization efficiency.
The high-pressure steam extraction volume is reduced, the steam engine output is increased, the combined cycle heat consumption is reduced, and the economicality of steam is improved.
Smart Images
Figure CN120466720A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a medium-pressure heating system for a waste heat boiler, belonging to the technical field of boiler equipment. Background Art
[0002] With the development of power plant boiler technology, the use of cold reheat steam for heating has become widely used. In the waste heat boiler medium-pressure heating system, the medium-pressure heating steam pipeline 1 is connected to the cold reheat steam pipeline 2. The cold reheat steam from the steam turbine extraction port is sent to the medium-pressure heating user through the medium-pressure heating steam pipeline 1 (see attached). Figure 1 ). To accommodate situations where the steam pressure required by medium-pressure heating users is greater than the reheat steam pressure, the medium-pressure heating steam pipeline 1 is also connected to the high-pressure main steam pipeline 3. The high-pressure main steam from the high-pressure superheater is desuperheated and depressurized to provide heat to medium-pressure heating users. The disadvantages of the aforementioned medium-pressure heating system are: extracting a large amount of high-pressure steam from the high-pressure superheater for medium-pressure heating will inevitably reduce the steam flow from the high-pressure superheater to the steam turbine, affecting turbine output. Furthermore, the high-pressure steam from the high-pressure superheater is of relatively high quality and requires desuperheating and depressurization to match the heating parameters of medium-pressure heating users. This desuperheating and depressurization results in significant heat loss, resulting in unsatisfactory steam supply economics and a high combined cycle heat consumption. Summary of the Invention
[0003] The present invention mainly solves the technical problem in the prior art that high-pressure steam extraction affects the output of the steam turbine and leads to high heat consumption of the combined cycle, and provides a waste heat boiler medium-pressure heating system with less high-pressure steam extraction and lower combined cycle heat consumption.
[0004] The present invention solves the above technical problems mainly through the following technical solutions: the present invention includes a medium-pressure heating steam pipeline, a cold re-steam pipeline, and a high-pressure main steam pipeline, and is characterized in that it also includes a pressure matcher, the medium-pressure heating steam pipeline inlet is connected to the pressure matcher outlet, the cold re-steam pipeline outlet is connected to the low-pressure steam inlet of the pressure matcher, the high-pressure main steam pipeline outlet is connected to the high-pressure steam inlet of the pressure matcher, the cold re-steam uses the high-pressure main steam as the power source and enters the medium-pressure heating steam pipeline after pressure expansion in the pressure matcher, and the medium-pressure heating steam pipeline outlet is connected to the medium-pressure heating user.
[0005] Preferably, it also includes a cooling water pipeline, which is connected to the medium-pressure heating steam pipeline.
[0006] Preferably, the cold re-steam pipeline is provided with a cold re-steam control valve.
[0007] Preferably, the high-pressure main steam pipeline is provided with a high-pressure main steam control valve.
[0008] The present invention has a simple structure and has the following advantages: In the present invention, a pressure matcher is installed at the inlet of the medium-pressure heating steam pipeline. The cold re-steam is mixed and expanded with the high-pressure main steam in the pressure matcher before being fed into the medium-pressure heating steam pipeline. When the pressure of the cold re-steam is lower than the medium-pressure heating steam pressure parameter, the cold re-steam can be pressurized with the help of the pressure matcher and the high-pressure main steam and used for medium-pressure heating, thereby greatly improving the efficient utilization of the cold re-steam. In the present invention, the high-pressure main steam is extracted only to pressurize the cold re-steam. Therefore, compared with extracting high-pressure main steam directly to supply steam to the medium-pressure heating pipeline, the extraction of high-pressure main steam is significantly reduced, the impact on steam turbine output is greatly reduced, and the heat consumption of the combined cycle is also significantly reduced.
[0009] Furthermore, a cooling water pipeline is provided to provide cooling water to the medium-pressure heating steam pipeline. By mixing the cooling water with the steam from the pressure matcher, the temperature of the mixed steam can be more accurately matched to the temperature parameters of the medium-pressure heating.
[0010] Furthermore, the flow rates of the cold re-steam and the high-pressure main steam entering the pressure matcher can be adjusted and controlled by the control valve according to the operating conditions.
[0011] Therefore, compared with the prior art, the present invention has the beneficial effects of less high-pressure steam extraction, higher steam turbine output, and lower combined cycle heat consumption. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Attachment Figure 1 It is a schematic diagram of the prior art.
[0013] Attachment Figure 2 It is a schematic diagram of a preferred embodiment of the present invention.
[0014] Explanation of the accompanying symbols: 1. Medium-pressure heating steam pipeline; 2. Cold reheating steam pipeline; 21. Cold reheating steam control valve; 3. High-pressure main steam pipeline; 31. High-pressure main steam control valve; 4. Pressure matcher; 5. Cooling water pipeline. DETAILED DESCRIPTION
[0015] The technical solution of the present invention will be further specifically described below through embodiments and in conjunction with the accompanying drawings.
[0016] Example 1: As shown in the attached Figure 1 As shown, the present invention includes a medium-pressure heating steam pipeline 1, a cooling steam pipeline 2, a high-pressure main steam pipeline 3, a pressure matching device 4, and a desuperheating water pipeline 5; The inlet of the medium-pressure heating steam pipeline 1 is connected to the outlet of the pressure matcher 4, the outlet of the cold re-steam pipeline 2 is connected to the low-pressure steam inlet of the pressure matcher 4, and the outlet of the high-pressure main steam pipeline 3 is connected to the high-pressure steam inlet of the pressure matcher 4. The cold re-steam uses the high-pressure main steam as the power source and enters the medium-pressure heating steam pipeline 1 after pressure expansion in the pressure matcher 4. The attemperating water pipeline 5 is connected to the medium-pressure heating steam pipeline 1. The steam from the outlet of the pressure matcher 4 and the attemperating water are mixed in the medium-pressure heating steam pipeline 1 and then cooled to a temperature that matches the medium-pressure heating parameters. The outlet of the medium-pressure heating steam pipeline 1 is connected to the medium-pressure heating user; The cold re-steam pipeline 2 is provided with a cold re-steam control valve 21; The high-pressure main steam pipeline 3 is provided with a high-pressure main steam control valve 31 .
[0017] The present invention is applied to a power plant boiler project. The medium-pressure heating parameters are 4 MPa.g, 400°C, and 40 t / h. The comparative data of high-pressure extraction steam, steam turbine output, and combined cycle heat consumption are as follows: High-pressure steam extraction Steam turbine output (baseline difference) Combined cycle heat rate (benchmark difference) Existing technology 38t / h —316KW +4 KJ / KW.h The present invention 26t / h +397KW —5 KJ / KW.h It can be seen that compared with the prior art, the high-pressure steam extraction of the present invention is reduced by 12t / h, the steam turbine output is increased by 713KW, and the combined cycle heat consumption is reduced by 9 KJ / KW.h.
[0018] Of course, the above drawings and embodiments are only used to explain and illustrate the present invention and cannot be used as improper limitations of the present invention. Any technical solutions obtained by those skilled in the art by making equivalent adjustments and changes based on the present invention fall within the scope of protection of the present invention.
Claims
1. A medium-pressure heating system for a waste heat boiler, comprising a medium-pressure heating steam pipeline (1), a cold reheat steam pipeline (2), and a high-pressure main steam pipeline (3), characterized in that: It also includes a pressure matcher (4), wherein the inlet of the medium-pressure heating steam pipeline (1) is connected to the outlet of the pressure matcher (4), the outlet of the cold re-steam pipeline (2) is connected to the low-pressure steam inlet of the pressure matcher (4), and the outlet of the high-pressure main steam pipeline (3) is connected to the high-pressure steam inlet of the pressure matcher (4). The cold re-steam uses the high-pressure main steam as a power source and enters the medium-pressure heating steam pipeline (1) after being expanded in the pressure matcher (4). The outlet of the medium-pressure heating steam pipeline (1) is connected to a medium-pressure heating user.
2. The medium-pressure heating system of a waste heat boiler according to claim 1, characterized in that: It also includes a desuperheating water pipeline (5), which is connected to the medium-pressure heating steam pipeline (1).
3. The medium-pressure heating system of a waste heat boiler according to claim 1, characterized in that: The cold resteam pipeline (2) is provided with a cold resteam control valve (21).
4. The medium-pressure heating system of a waste heat boiler according to claim 2, characterized in that: The high-pressure steam extraction pipeline (3) is provided with a high-pressure main steam control valve (31).