CN111623398A - Energy cascade utilization system for steam turbine at first station of heat supply network - Google Patents

Abstract

The invention provides a step utilization system for steam turbine energy in the first station of the heat network, which includes a steam mechanism, a circulating water mechanism for the heat network and a hydrophobic condensate mechanism. The steam mechanism includes a steam turbine unit, a steam turbine in the first station of the heat network, and a heater in the heat network. The heating pipeline of the steam turbine unit is connected to the steam turbine in the first station of the heat network; the steam turbine in the first station of the heat network has an extraction pipeline and an exhaust pipeline. It is connected to the heater of the heat network, and the exhaust pipe is connected to the input end of the high back pressure condenser; the circulating water mechanism of the heat network includes a high back pressure condenser, and the circulating return water of the heat network is connected to the high back pressure The output end of the pressure condenser is connected to the input end of the heating network heater, and the heating network heater is connected to the circulating water supply of the heating network; the drainage condensate water mechanism includes a normal drainage pipe, the output end of the normal drainage pipe is connected to the heating network heater, and the input end is connected To the high back pressure condenser condensate tank, the condensate tank of the high back pressure condenser is connected to the steam turbine unit hot well. The invention improves the energy utilization rate and avoids energy waste.

Description

A step-by-step utilization system for steam turbine energy in the first station of heat network

technical field

The present application relates to the technical field of thermal power generation, and in particular, to a system for utilizing the energy of a steam turbine in the first station of a heat grid.

Background technique

Central heating in power plants is the most economical and environmentally friendly way of heating. While meeting the heating needs of residents, power plants can increase heat sales revenue and have good economic and social benefits.

In order to meet the increasing heating demand of residents, many power plants have carried out heating transformation for pure condensing steam turbines. For 660MW units, heating and steam extraction are increased by the transformation of medium and low pressure connecting pipes. In this case, the steam extraction pressure is high (greater than 0.8MPa). In order to reduce the equipment price of the heating network heater, a pressure reducer is generally set to decompress the steam to 0.3-0.5MPa.a, and then connected to the heating network heater. In this process, the energy of the steam pressure difference is not utilized, resulting in energy waste.

SUMMARY OF THE INVENTION

The present application provides a step-by-step energy utilization system for the steam turbine of the first station of the heat grid, so as to solve the problem that the energy of the steam pressure difference is not utilized, resulting in energy waste.

The technical scheme adopted in this application is as follows:

The invention provides a step utilization system for steam turbine energy in the first station of the heat grid, including:

a steam mechanism, the steam mechanism includes a steam turbine unit, a steam turbine at the first station of the heat network, and a heater in the heat network, the steam turbine unit has a heating pipeline, and the heating pipeline is connected to the steam turbine at the first station of the heat network; the first station of the heat network The output end of the steam turbine has an extraction steam pipeline and an exhaust steam pipeline, the extraction steam pipeline is connected to the heat network heater, and the exhaust steam pipeline is connected to the input end of the high back pressure condenser;

The heat network circulating water mechanism includes a high back pressure condenser, the heat network circulating return water is connected to the high back pressure condenser, and the output end of the high back pressure condenser is connected to the high back pressure condenser. The input end of the heating network heater is connected, and the heating network heater is connected to the circulating water supply of the heating network;

A hydrophobic condensate mechanism, the hydrophobic condensate mechanism includes a normal drain pipe, the output end of the normal drain pipe is connected to the heat network heater, and the input end is connected to the condensate tank of the high back pressure condenser, the high back pressure condenser The condensate tank of the back pressure condenser is connected to the hot well of the steam turbine unit.

Further, the hydrophobic condensate mechanism further includes an emergency hydrophobic output pipe connected to the heat network heater.

Further, the hydrophobic condensate water mechanism further comprises a heat network critical hydrophobic expansion container, the critical hydrophobic output pipe is connected to the input end of the heat network critical hydrophobic expansion container, and the output end of the heat network critical hydrophobic expansion container is connected There are drainage pipes and the drainage pipes are connected to a drainage network.

Further, cooling water is connected to the drainage pipe.

Further, the high back pressure condenser and the hot well are connected by a condensate pipe, and a shaft seal heater is provided on the condensate pipe.

Further, a condensate water pump is also included, the condensate water pump is arranged on the condensate water pipe and is located between the shaft seal heater and the high back pressure condenser.

Further, the heat network circulating water mechanism also includes a water filter, the input end of the water filter is connected to the return water of the heat network circulating water in the first station of the heat network, and the output end of the water filter is connected to the High back pressure condenser.

Further, the output end of the high back pressure condenser is connected with the input end of the heating network heater through a connecting pipeline, and a heating network circulating pump is connected to the connecting pipeline.

Further, a generator is connected to the steam turbine of the first station of the heat grid.

The beneficial effects of adopting the technical solution of the present application are as follows:

The energy ladder utilization system of the steam turbine in the first station of the heat network of the present invention adopts the steam turbine of the first station of the heat network to replace the pressure reducer, makes full use of the pressure difference energy, increases the power generation and reduces the power consumption of the plant. At the same time, the steam turbine of the first station of the heat network adopts a high back pressure condenser, and uses low-quality exhaust steam to heat the circulating water of the heat network in the first stage, so as to improve the energy utilization efficiency.

Description of drawings

In order to illustrate the technical solutions of the present application more clearly, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, without creative work, the Additional drawings can be obtained from these drawings.

Figure 1 is a schematic structural diagram of a steam turbine energy ladder utilization system for the first station of the heat network (only the first station of the newly built heat network);

Figure 2 is a schematic diagram of the structure of a steam turbine energy ladder utilization system for the first station of the heat network (including the first station of the new heat network and the first station of the original heat network).

Illustration description:

Among them, 1- steam mechanism: 11- steam turbine unit; 12- steam turbine of the first station of heat network; 13, heater of heat network; 14, heat well; 15- generator;

2-Heat network circulating water mechanism: 21-high back pressure condenser; 22-shaft seal heater; 23-water filter; 24-heat network circulating pump; 25-heat network circulating water return water; 26-heat network circulating water supply;

3- Drainage condensate mechanism: 31-normal drainage pipe; 32-critical drainage output pipe; 33-critical drainage expansion container of heat network; 34-condensation pump; 35-cooling water; 36-drainage pipe network.

4- The first station of the original heat network; 41- The first station of the original heat network to expel steam; 42- The first station of the original heat network to circulate back water; 43- The first station of the original heat network heater.

Detailed ways

Embodiments will be described in detail below, examples of which are illustrated in the accompanying drawings. Where the following description refers to the drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the following examples are not intended to represent all implementations consistent with this application. are merely exemplary of systems and methods consistent with some aspects of the present application as recited in the claims.

Referring to FIG. 1 , it is a schematic structural diagram of an energy ladder utilization system for the steam turbine 12 in the first station of the heat grid.

The application provides an energy stepped utilization system of the steam turbine 12 in the first station of the heat network, which includes a steam mechanism, a circulating water mechanism for the heat network, and a hydrophobic condensate mechanism.

As shown in Figure 1, specifically:

The steam mechanism includes a steam turbine unit 11, a steam turbine 12 at the first station of the heat network, and a heater 13 in the heat network. The steam turbine unit 11 has a heating pipeline, and the heating pipeline is connected to the steam turbine 12 at the first station of the heat network; the output end of the steam turbine 12 at the first station of the heat network has extraction steam. The pipeline and the exhaust pipeline, the extraction pipeline is connected to the heat network heater 13, and the exhaust pipeline is connected to the input end of the high back pressure condenser 21, wherein the steam turbine 12 of the first station of the heat network is connected to the power generation machine 15;

The heat network circulating water mechanism includes a high back pressure condenser 21, the heat network circulating return water 25 is connected to the high back pressure condenser 21, and the output end of the high back pressure condenser 21 is connected to the input end of the heat network heater 13, The heating network heater 13 is connected to the heating network circulating water supply 26;

The drain condensate mechanism includes a normal drain pipe 31 , an emergency drain output pipe 32 and a heat network emergency drain expansion vessel 33 . The output end of the normal drain pipe 31 is connected to the heat network heater 13 , and the input end is connected to the condensate tank of the high back pressure condenser 21 , the condensed water tank of the high back pressure condenser 21 is connected to the hot well 14 of the steam turbine unit 11, the output end of the critical drainage output pipe 32 is connected to the heating grid heater 13, and the input end of the critical drainage output pipe is connected to the hot grid critical drainage expansion vessel 33. A drain pipe is connected to the output end of the heat network emergency drain expansion container 33 and the drain pipe is connected to a drain pipe network 36, and cooling water 35 is connected to the drain pipe.

The steam turbine unit 11 in this embodiment is specifically a 660MW steam turbine unit 11 .

The high back pressure condenser 21 and the hot well 14 are connected by a condensate pipe, the condensate pipe is provided with a shaft seal heater 22, and the condensate pump 34 is arranged on the condensate pipe and is located between the shaft seal heater 22 and the high back pressure condensate between devices 21. The normal drain of the heat network heater 13 enters the high back pressure condenser 21, mixes with the condensate water and then enters the condensate pump 34 for pressure, and the shaft seal leakage heat is recovered by the shaft seal heater 22, and then enters the The steam exhaust device hot well 14 and the shaft seal heater 22 have the function of recovering the heat of the shaft seal leakage steam. The condensate water pump 34 is used for pumping the condensate water of the pressurized high back pressure condenser 21 .

It also includes a water filter 23 , the input end of the water filter 23 is connected to the circulating return water 25 of the heat network first station, and the output end of the water filter 23 is connected to the high back pressure condenser 21 . The water filter 23 is used to filter the impurities in the circulating return water 25 of the heating network in the first station of the heating network, so as to prevent the impurities in the circulating water 25 of the heating network in the first station of the heating network from entering the circulation of the heating network.

Among them, the heat network heater 13 is connected with a normal drain pipe 31 and an emergency drain output pipe 32, the normal drain of the heat network heater 13 enters the high back pressure condenser 21, and when the amount of drain is large and the water level is high, it can pass The critical drain output pipe 32 is discharged, and the critical drain expansion container 33 of the heat network can expand and depressurize the critical drain and then discharge it through the drain pipe. After the critical drainage and cooling water are mixed, the temperature reaches about 40°C, and then it is discharged into the drainage pipe network. The cooling water in this embodiment comes from a cooling tower.

The connecting pipeline includes two pipelines with different diameters, namely the first connecting pipeline and the second connecting pipeline. The output end of the high back pressure condenser 21 and the input end of the heat network heater 13 pass through the first connecting pipeline. Connection, the first connecting pipeline is connected with a heat network circulating pump 24.

The working principle of this embodiment is as follows: the heating steam from the 660MW steam turbine unit 11 enters the steam turbine 12 of the first station of the heat network through the heating pipeline, and the extraction steam (high pressure steam) from the steam turbine 12 of the first station of the heat network enters the heater 13 of the heat network for heating directly. The circulating water supply 26 enters the first station of the heat network for heating; the circulating return water 25 of the heat network is filtered by the water filter 23 and enters the high back pressure condenser 21, and the exhaust steam (low pressure steam) from the steam turbine 12 of the first station of the heat network enters the high back pressure The condenser 21 performs primary heating for the circulating return water entering the high back pressure condenser 21, and then enters the heating network heater 13 through the first connecting pipeline and through the heating network circulating pump 24 for secondary heating, and then enters The first station of the heat network circulates water for heating; the normal drain of the heat network heater 13 enters the high back pressure condenser 21, mixes with the condensed water of the high back pressure condenser 21, and then enters the condensate pump 34 for pressure, and is heated by the shaft seal The steam leakage heat from the shaft seal is recovered by the device 22, and then enters the heat well 14; the critical drainage of the heat network heater 13 enters the heat network emergency expansion container to expand the capacity and reduce the pressure, and then discharge through the drainage pipe.

In this embodiment, the steam turbine 12 of the first station of the heating network is used to replace the pressure reducer, and the pressure difference energy is fully utilized to increase the power generation and reduce the power consumption of the plant. Perform primary heating, make full use of the low-quality heat of exhaust steam, and improve energy utilization efficiency.

At the same time, as shown in Figure 2, it also includes the heater of the first station of the original heat network, and the output end of the high back pressure condenser 21 is connected with the heater of the first station of the original heat network through the second connecting pipeline; The exhaust steam 41 of the station is connected to the heating network heater 13 , and the circulating return water 42 of the original heating network first station heating network is connected to the input end of the water filter 23 .

Since the first station of the original heat network already exists in the power plant of this embodiment, the circulating return water of the first station of the original heat network is filtered by the water filter 23 and enters the high back pressure condenser 21, and the discharge water from the steam turbine 12 of the first station of the newly-built heat network is filtered. The steam (low pressure steam) enters the high back pressure condenser 21 and conducts primary heating of the circulating return water 42 entering the first station of the original heat network of the high back pressure condenser 21, and then enters the original heat network through the second connecting pipeline The heater in the first station performs secondary heating; and the exhaust steam 41 of the first station of the original heat network is connected to the heater 13 of the heat network to improve the energy utilization efficiency.

Similar parts between the embodiments provided in the present application may be referred to each other. The specific embodiments provided above are just a few examples under the general concept of the present application, and do not constitute a limitation on the protection scope of the present application. For those skilled in the art, any other implementations expanded according to the solution of the present application without creative work fall within the protection scope of the present application.

Claims (9)

1. A heat supply network initial stage steam turbine energy ladder utilization system is characterized by comprising:

the steam mechanism comprises a steam turbine set, a heat supply network initial station steam turbine and a heat supply network heater, wherein the steam turbine set is provided with a heating pipeline, and the heating pipeline is connected to the heat supply network initial station steam turbine; the output end of the steam turbine at the first station of the heat supply network is provided with a steam extraction pipeline and a steam exhaust pipeline, the steam extraction pipeline is connected to the heat supply network heater, and the steam exhaust pipeline is connected to the input end of the high-back-pressure condenser;

the heat supply network circulating water mechanism comprises a high-backpressure condenser, the circulating backwater of the heat supply network is connected to the high-backpressure condenser, the output end of the high-backpressure condenser is connected with the input end of the heat supply network heater, and the heat supply network heater is connected to circulating water supply of the heat supply network;

the drainage condensed water mechanism comprises a normal drainage pipe, the output end of the normal drainage pipe is connected with the heat supply network heater, the input end of the normal drainage pipe is connected to the condensed water tank of the high-back-pressure condenser, and the condensed water tank of the high-back-pressure condenser is connected to the hot well of the turbine unit.

2. The heat supply network head steam turbine energy staging system of claim 1 wherein: the hydrophobic condensed water mechanism also comprises a critical hydrophobic output pipe connected to the heat supply network heater.

3. The heat supply network head steam turbine energy staging system of claim 2 wherein: hydrophobic condensation water mechanism still includes the hydrophobic flash tank of heat supply network emergency, the hydrophobic output tube of emergency is connected to the input of the hydrophobic flash tank of heat supply network emergency, the output of the hydrophobic flash tank of heat supply network emergency is connected with drainage pipe just drainage pipe is connected to drainage pipe network.

4. The heat supply network head steam turbine energy staging system of claim 3 wherein: and cooling water is connected to the drainage pipeline.

5. The heat supply network head steam turbine energy staging system of claim 1 wherein: the high back pressure condenser is connected with the hot well through a condensate pipe, and a shaft seal heater is arranged on the condensate pipe.

6. The heat supply network head steam turbine energy staging system of claim 5 wherein: the high-back-pressure condenser is characterized by further comprising a condensate pump, wherein the condensate pump is arranged on the condensate pipe and is positioned between the shaft seal heater and the high-back-pressure condenser.

7. The heat supply network head steam turbine energy staging system of claim 1 wherein: the heat supply network circulating water mechanism further comprises a water filter, the input end of the water filter is connected with the heat supply network circulating water return water of the heat supply network initial station, and the output end of the water filter is connected to the high-backpressure condenser.

8. The heat supply network head steam turbine energy staging system of claim 7 wherein: the output end of the high back pressure condenser is connected with the input end of the heat supply network heater through a connecting pipeline, and the connecting pipeline is connected with a heat supply network circulating pump.

9. The heat supply network head steam turbine energy cascade utilization system according to any one of claims 1 to 8, wherein: and the steam turbine at the first station of the heat supply network is connected with a generator.

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