Core package protection system of water feeding pump

Abstract

The utility model discloses a feed pump core cladding protection system which comprises a circulating fluidized bed boiler, an outlet of the circulating fluidized bed boiler is communicated with an inlet of a steam turbine, an outlet of the steam turbine is communicated with an inlet of a condensate pump, and an outlet of the condensate pump is respectively communicated with an inlet of a slag cooler and an inlet of a booster pump. An outlet of the slag cooler is communicated with an inlet of the water feeding pump through a low-pressure heater and a deaerator in sequence; the booster pump outlet is communicated with the feed pump inlet; the outlet of the high-pressure heater is communicated with the inlet of the circulating fluidized bed boiler. According to the system, a bypass is additionally arranged beside a pipeline, leading to sealing water of a feed pump, of a condensate pump, a booster pump is additionally arranged on the bypass, and the pressure of condensate entering the feed pump seal is adjusted. The lowest pressure of the outlet of the condensate pump is set, once the pressure is smaller than the minimum pressure required by a sealing system, the booster pump is started immediately, stable condensate pressure is guaranteed, a water pump core bag is prevented from being damaged, and safe operation of a unit is guaranteed.

Description

Technical Field

[0001] The utility model relates to the field of energy-saving equipment, in particular to a water supply pump core package protection system. Background Art

[0002] The circulating fluidized bed boiler uses the slag cooler to reduce the temperature of the boiler slag through condensate and recover the heat of the boiler slag to improve the economy of the unit. Although the purpose of solid waste utilization has been achieved, the internal pipe wall of the slag cooler is easy to wear, the scaling phenomenon inside the cooling water pipe is obvious, the rotary joint sealing device is damaged, and the slag cooler is improperly operated, which can cause the slag cooler to burst during the operation of the unit. The cooling water of the slag cooler is connected to the outlet of the condensate pump. Once the slag cooler bursts, the condensate pump will be depressurized, the condensate pressure will be reduced, and it will not be able to meet the sealing water pressure requirements of the feed pump, resulting in permanent damage to the feed pump core pack, which needs to be replaced with a new core pack.

[0003] At the same time, due to the damage of the feed water pump, the water supply will be immediately withdrawn from use. If the standby pump cannot be started in time, the unit will experience unplanned shutdown, which will cause great safety hazards and economic losses. Even if the standby feed water pump can be started, the general standby pump is 35% or 50% of the capacity and can only operate at partial load, which is difficult to meet the requirements of grid dispatching and will still bring great economic losses. If it is in the winter heating period, it will also affect heating and cause livelihood problems. Therefore, it is very necessary to prevent the slag cooler from bursting and ensure the stability of condensate water pressure. Utility Model Content

[0004] The utility model provides a feed water pump core pack protection system, which aims to prevent the slag cooler from bursting, ensure the stability of the condensate water pressure, prevent the feed water pump core pack from being damaged due to insufficient feed pump sealing water pressure, and ensure the safe operation of the unit.

[0005] To achieve its purpose, the utility model adopts the following technical solutions:

[0006] A feedwater pump core package protection system includes a circulating fluidized bed boiler, wherein the outlet of the circulating fluidized bed boiler is communicated with the inlet of a steam turbine, the outlet of the steam turbine is communicated with the inlet of a condensate pump, the outlet of the condensate pump is communicated with the inlet of a slag cooler and the inlet of a booster pump respectively; the outlet of the slag cooler is communicated with the inlet of the feedwater pump via a low-pressure heater and a deaerator in sequence; the outlet of the booster pump is communicated with the inlet of the feedwater pump; the outlet of the feedwater pump is communicated with the inlet of a high-pressure heater, and the outlet of the high-pressure heater is communicated with the inlet of the circulating fluidized bed boiler.

[0007] Preferably, a first control valve is provided at the inlet of the slag cooler.

[0008] Preferably, a pressure gauge and a second control valve are provided in sequence on the pipeline connecting the condensate pump and the booster pump.

[0009] Preferably, the pressure gauge is electrically connected to the signal input end of the DCS control system, and the signal output end of the DCS control system is electrically connected to the first control valve, the second control valve and the booster pump respectively.

[0010] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0011] 1. This system adds a bypass next to the pipeline from the condensate pump to the seal water of the feed pump, and adds a booster pump on the bypass to adjust the condensate pressure entering the feed pump seal. According to the minimum pressure required by the feed pump seal water, taking into account the loss along the way and the elevation difference, the minimum pressure at the outlet of the condensate pump is set. Once the pressure is lower than the minimum pressure required by the sealing system, the booster pump is immediately activated to increase the pressure entering the seal water system to ensure the stability of the condensate pressure, prevent the damage to the feed pump core package caused by insufficient feed pump seal water pressure, and ensure the safe operation of the unit.

[0012] 2. This system uses a booster pump to ensure the pressure of the sealing water. It can reduce the speed of the condensate pump when the unit is in deep peak regulation, reduce the power consumption of the condensate pump, and use the booster pump to ensure the minimum pressure required for the feed pump seal, thereby improving the unit's operating economy and saving energy and protecting the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the structural diagram of the system;

[0014] In the figure: 1-circulating fluidized bed boiler; 2-steam turbine; 3-condensate pump; 4-pressure gauge; 5-first control valve; 6-slag cooler; 7-low-pressure heater; 8-deaerator; 9-feedwater pump; 10-boosting pump; 11-second control valve; 12-high-pressure heater. DETAILED DESCRIPTION

[0015] The utility model is further described below in conjunction with the accompanying drawings:

[0016] like Figure 1As shown, the utility model is a feedwater pump core package protection system, comprising a circulating fluidized bed boiler 1, wherein the outlet of the circulating fluidized bed boiler 1 is communicated with the inlet of the steam turbine 2, the outlet of the steam turbine 2 is communicated with the inlet of the condensate pump 3, the outlet of the condensate pump 3 is communicated with the inlet of the slag cooler 6 and the inlet of the booster pump 10 respectively, a first control valve 5 is provided at the inlet of the slag cooler 6, and a pressure gauge 4 and a second control valve 11 are provided on the pipeline communicating with the condensate pump 3 and the booster pump 10 in sequence, wherein the pressure gauge 4 is electrically connected to the signal input end of the DCS control system, and the signal output end of the DCS control system is electrically connected to the first control valve 5, the second control valve 11 and the booster pump 10 respectively. The outlet of the slag cooler 6 is communicated with the inlet of the feedwater pump 9 through the low-pressure heater 7 and the deaerator 8 in sequence; the outlet of the booster pump 10 is communicated with the inlet of the feedwater pump 9; the outlet of the feedwater pump 9 is communicated with the inlet of the high-pressure heater 12, and the outlet of the high-pressure heater 12 is communicated with the inlet of the circulating fluidized bed boiler 1.

[0017] The feed water is heated in the circulating fluidized bed boiler 1 to become superheated steam and is passed into the steam turbine 2 to do work. After doing work, the exhaust steam is condensed into condensate through the condenser. The condensate is pressurized by the condensate pump 3 and enters the slag cooler 6. The pressure gauge 4 at the outlet of the condensate pump 3 measures the pressure at the outlet of the condensate pump 3 in real time. When the pressure value of the condensate pump 3 is greater than the minimum pressure required for the sealing water of the feed water pump 9, a small part of the condensate normally enters the feed water pump sealing system through the sealing water pipeline, and most of the condensate enters the slag cooler 6. The condensate flow is controlled by the first control valve 5. When the pressure value of the condensate pump 3 is less than the minimum pressure required by the sealing system, the pressure gauge 4 feeds back the signal to the DCS control system of the whole machine protection system. The DCS control system receives the signal to control the second control valve 11 and the booster pump 10 to open, and part of the condensate enters the sealing water pipeline through the booster pump 10 to increase the pressure entering the sealing water system, and the rest of the condensate enters the slag cooler 6 normally. The condensate is heated by the slag cooler 6 and then enters the low-pressure heater 7, then enters the deaerator 8 for deoxygenation and heating, then enters the high-pressure heater 12 after being pressurized by the feedwater pump 9, and finally returns to the circulating fluidized bed boiler 1. The fuel is burned in the circulating fluidized bed boiler 1 to become slag. The temperature of the boiler slag is high and difficult to store and transport. This part of the heat can also be used. The boiler slag enters the slag cooler 6 for cooling and heating the condensate.

Claims

1. A feedwater pump core protection system, comprising a circulating fluidized bed boiler (1), wherein the outlet of the circulating fluidized bed boiler (1) is communicated with the inlet of a steam turbine (2), and the outlet of the steam turbine (2) is communicated with the inlet of a condensate pump (3), characterized in that: The outlet of the condensate pump (3) is respectively connected to the inlet of the slag cooler (6) and the inlet of the booster pump (10); the outlet of the slag cooler (6) is connected to the inlet of the feed water pump (9) through the low-pressure heater (7) and the deaerator (8) in sequence; the outlet of the booster pump (10) is connected to the inlet of the feed water pump (9); the outlet of the feed water pump (9) is connected to the inlet of the high-pressure heater (12), and the outlet of the high-pressure heater (12) is connected to the inlet of the circulating fluidized bed boiler (1).

2. A water pump core protection system as claimed in claim 1, characterized in that: A first control valve (5) is provided at the inlet of the slag cooler (6).

3. A water pump core protection system as claimed in claim 2, characterized in that: A pressure gauge (4) and a second control valve (11) are provided in sequence on the pipeline connecting the condensate pump (3) and the booster pump (10).

4. A water pump core protection system as claimed in claim 3, characterized in that: The pressure gauge (4) is electrically connected to a signal input end of a DCS control system, and a signal output end of the DCS control system is electrically connected to the first control valve (5), the second control valve (11) and the booster pump (10), respectively.

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