CN222027038U - Energy-saving heat supply system for thermal power plant - Google Patents

Abstract

The utility model provides an energy-saving heating system for a thermal power plant, which relates to the technical field of waste heat recovery and comprises the following components: an absorption heat pump comprising a generator, an absorber, an evaporator and a condenser connected; the low-pressure cylinder of the steam turbine, after entering the low-pressure cylinder of the steam turbine to do work, a part of low-pressure steam enters the generator to be used as driving steam of the heat pump; a part of exhaust steam enters condensing equipment to be cooled and condensed into condensed water; the other part of the exhaust steam enters an evaporator to be subjected to heat release and condensation to form condensation water; the exhaust steam condensate water enters the exhaust steam device hot well through the condensing equipment and the evaporator, and returns to the boiler system for circulation; the water inlet pipeline and the water outlet pipeline are connected to form a circulating pipeline; the water inlet pipeline is subjected to primary heating through heat exchange of the absorber in sequence, and then subjected to secondary heating through heat exchange of the condenser; and then connected to the water outlet pipe. The utility model reduces the back pressure of the turbine of the power plant and improves the generating efficiency of the unit.

Description

Energy-saving heat supply system for thermal power plant

Technical Field

The utility model relates to the technical field of waste heat recovery, in particular to an energy-saving heat supply system for a thermal power plant.

Background

For a long time, the cold end loss of the Rankine cycle of the thermal power plant accounts for more than half of the energy loss of the whole power plant, whether the Rankine cycle is a direct air cooling unit, an indirect air cooling unit or a water cooling steam turbine unit, a large amount of heat (mainly the vaporization latent heat of steam) carried by exhaust steam discharged after the steam turbine does work is not fully recycled, and meanwhile, in order to recycle and save water resources, the water of the exhaust steam also needs to be recycled, but a large amount of water resources (water cooling towers), power consumption (water pumps, fans) and the like are also needed to be consumed for recycling and cooling the exhaust steam. If the exhaust steam of the turbine of the thermal power plant is recycled, a large amount of latent heat of vaporization can be recycled, the loss of water resources can be reduced, the back pressure of the turbine can be reduced, and the power generation efficiency and the power generation load of the power plant can be improved. The waste steam energy of the turbine set is recycled and used for heating heat supply network water and other places needing heat sources, and the cold end loss is reduced, so that the method is an effective energy-saving means.

To solve the above problems, the conventional methods mainly include:

For the problem of high back pressure of a turbine of a power plant, part of power plants adopt modes (namely peak cooling technology) of increasing the heat exchange area of a cooling tower for cooling circulating water and the like, the technology can effectively reduce the back pressure of the turbine and improve the power generation load of a unit, but the mode does not recycle the heat of exhaust steam.

Based on the above reasons, the present utility model provides an energy-saving heating system for a thermal power plant to solve the above technical problems.

Disclosure of utility model

The utility model aims to provide an energy-saving heat supply system for a thermal power plant, which can utilize condensation water after exhaust steam condensation, reduce waste of water resources of the coal-fired power plant and improve energy utilization rate;

The utility model provides an energy-saving heat supply system for a thermal power plant, which comprises: an absorption heat pump comprising a generator, an absorber, an evaporator and a condenser connected; the low-pressure cylinder of the steam turbine, after entering the low-pressure cylinder of the steam turbine to do work, a part of low-pressure steam enters the generator to be used as driving steam of the heat pump; a part of exhaust steam enters condensing equipment to be cooled and condensed into condensed water; the other part of exhaust steam enters the evaporator to be subjected to heat release and condensation to form condensation water; the exhaust steam condensate water enters the exhaust steam device heating well through the condensing equipment and the two parts of the evaporator, and returns to the boiler system for circulation; the water inlet pipeline is connected with the water outlet pipeline to form a circulating pipeline; the water inlet pipeline is subjected to primary heating through heat exchange of the absorber in sequence, and then subjected to secondary heating through heat exchange of the condenser; and then to the outlet conduit.

Further, the utility model also comprises a water supply pipeline and a water return pipeline which are respectively communicated with the power plant heat supply network, wherein the water supply pipeline is connected to the water outlet pipeline, and the water return pipeline is connected to the water inlet pipeline.

Further, a condensation drain pump is connected to the steam exhaust device.

Further, the condensed water after the condensation of the two parts of dead steam is pumped to a boiler system through the condensed drain pump.

Further, a circulating water pump is arranged between the water inlet pipeline and the water outlet pipeline.

Further, the heat pump solution heating device also comprises a condensation water tank, wherein the driving steam entering the generator heats and evaporates the heat pump solution, and then is condensed into condensation water which enters the condensation water tank.

Further, the condensation water tank is communicated with the steam exhaust device thermal well.

Further, the absorption heat pump also comprises a throttle valve, the throttle valve is positioned between the generator and the absorber, the concentrated solution in the generator enters the absorber through the throttle valve, low-pressure steam from the evaporator is absorbed under the condition of low pressure, and in the steam absorption process, heat is released, and the heat is transferred to the water inlet pipeline for one-time heating.

Further, the refrigerant vapor in the generator condenses in the condenser to release heat, and the heat is transferred to the water inlet pipeline for secondary heating.

Further, the condensing equipment is an air cooling island.

The device provided by the utility model can be used for effectively reducing the back pressure of the turbine of the power plant, improving the generating efficiency of the unit and recovering the vaporization latent heat of the exhaust steam. Compared with the prior art, the utility model has the following advantages: 1. the vaporization latent heat of the exhaust steam of the steam turbine can be effectively recovered, the back pressure of the steam turbine is effectively reduced, the generating efficiency of the unit is improved, and the generating load is improved; 2. the recovered heat is used for supplying heat, so that the economy of the power plant is improved. The device is applicable to but not limited to the fields of coal-fired power station boilers, industrial boilers and the like.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of the overall system of the present utility model;

FIG. 2 is a schematic diagram of an absorption heat pump system of the present utility model;

Reference numerals illustrate:

The system comprises a 1-absorption heat pump, a 2-generator, a 3-solution heat exchanger, a 4-absorber, a 5-solution pump, a 6-working medium pump, a 7-evaporator, an 8-throttle valve, a 9-condenser, a 10-turbine low-pressure steam inlet, a 11-turbine low-pressure cylinder, a 12-low-pressure cylinder steam extraction, a 13-first exhaust steam branch pipe, a 14-cooling fan, a 15-air cooling island, a 16-exhaust steam device heat well, a 17-exhaust steam condensing coil pipe, a 18-second exhaust steam branch pipe, a 19-drainage pipeline, a 20-condensation drainage pump, a 21-water supply pipeline, a 22-water outlet pipeline, a 23-circulating water pump, a 24-water inlet pipeline, a 25-water return pipeline, a 26-condensation water tank, a 27-throttle valve and a 28-condensation water pipeline.

Detailed Description

The technical solutions of the present utility model will be clearly and completely described in connection with the embodiments, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise. Furthermore, the terms "mounted," "connected," "coupled," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

Example 1

As shown in fig. 1-2, the present utility model provides an energy saving and heating system for a thermal power plant, comprising: an absorption heat pump 1 comprising a generator 2, an absorber 4, an evaporator 7 and a condenser 9 connected; the low-pressure cylinder 11 of the turbine, after the low-pressure steam inlet 10 of the turbine enters the low-pressure cylinder 11 of the turbine to do work, a part of low-pressure steam enters the generator 2 to be used as driving steam of the heat pump; a part of exhaust steam enters condensing equipment to be cooled and condensed into condensed water; the other part of the exhaust steam enters an evaporator 7 to be subjected to heat release and condensation to form condensation water; the exhaust steam device heat well 16, two parts of exhaust steam condensate water passing through condensing equipment and the evaporator 7 enter the exhaust steam device heat well 16 and return to a boiler system (not shown) for circulation; the water inlet pipeline 24 and the water outlet pipeline 22, and the water inlet pipeline 24 and the water outlet pipeline 22 are connected to form a circulating pipeline; the water inlet pipeline 24 is subjected to heat exchange through the absorber 4 in sequence to perform primary heating, and then subjected to heat exchange through the condenser 9 to perform secondary heating; and then to the water outlet conduit 22.

Specifically, the low-pressure steam inlet 10 (pipeline) of the steam turbine is connected with the low-pressure cylinder 11 of the steam turbine for steam inlet, and part of low-pressure steam after the low-pressure cylinder 11 of the steam turbine does work enters the generator 2 of the absorption heat pump 1 through the steam extraction 12 (pipeline) of the low-pressure cylinder to be used as driving steam of the heat pump. The low-pressure cylinder 11 of the steam turbine is connected with a first exhaust steam branch pipe 13 and a second exhaust steam branch pipe 18, the first exhaust steam branch pipe 13 is connected with condensing equipment, the condensing equipment is specifically an air cooling island 15, part of exhaust steam enters the air cooling island 15 for cooling and condensing, and a condensed water pipeline 28 is communicated to a steam exhaust device thermal well 16; the second exhaust steam branch pipe 18 is connected with the evaporator 7, and the other part of exhaust steam enters the interior of the evaporator 7 of the absorption heat pump 1 to release heat, and after the exhaust steam in the evaporator 7 releases heat and condenses, condensed water is communicated to the steam exhaust device heat well 16 through a drainage pipeline 19 connected with the evaporator 7.

The condensed water after the condensation of the two parts of dead steam is returned to the boiler system for circulation through the condensation drainage pump 20 and is used for power generation of the thermal power plant. The boiler system is an important component of a thermal power plant, heats water into steam for driving a steam turbine to generate electricity, and is the prior art, and the structure of the boiler system is not repeated in this embodiment.

The air cooling island 15 includes a cooling fan 14 for air cooling, and is a prior art, and the structure thereof will not be described again.

Example 2

As shown in fig. 1, the utility model further comprises a water supply pipeline 21 and a water return pipeline 25 which are respectively communicated with the power plant heat supply network, wherein the water supply pipeline 21 is connected to the water outlet pipeline 22, and the water return pipeline 25 is connected to the water inlet pipeline 24.

Specifically, the water supply pipeline 21 is a power plant heat supply pipe network water supply pipeline 21, and the water return pipeline 25 is a power plant heat supply pipe network water return pipeline 25. The low-temperature heat supply network backwater (about 35-50 ℃) in the backwater pipeline 25 enters the absorber 4 through the water inlet pipeline 24 for primary heating, the temperature can be raised to 40-55 ℃ after heat exchange in the absorber 4, then the heat supply network backwater enters the condenser 9 for secondary heating, the temperature can be raised to 60-90 ℃ after heat exchange in the condenser 9, and the heat supply network water after two-stage heating returns to the water outlet pipeline 22, so that the steam extraction amount of the heat supply network heater is reduced.

Example 3

As shown in fig. 1, a condensate drain pump 20 is connected to the steam exhaust device thermal well 16, and the condensate after the two parts of exhaust steam are condensed is sent to the boiler system through the condensate drain pump 20.

Specifically, the temperature of the exhaust steam after the steam turbine works is 52.55 ℃, the absolute pressure is 14kPa, part of the exhaust steam enters the exhaust steam condensing coil 17 of the heat pump evaporator 7 through a second exhaust steam pipeline to release heat, the low-temperature low-pressure heat pump steam absorbs heat in the evaporator 7 to enable the exhaust steam to be condensed into water, the water temperature is reduced to about 42 ℃, and the water returns to the heat well 16 of the steam exhaust device; the heat released by the exhaust steam is mainly latent heat of vaporization, the heat is larger, and the heat is transferred to the heat supply network water passing through the water inlet pipeline 24 through the action of the absorption heat pump 1 to carry out heat recovery.

In this embodiment, the condensate drain pump 20 pressurizes and sends the condensate (about 42 ℃) in the steam exhaust device thermal well 16 to the power plant boiler system through the condensate pipeline 28 for power generation, thereby avoiding the waste of power plant water resources, and the condensate also has a temperature of about 42 ℃, so that the boiler system has low heating energy consumption for the condensate, thereby improving the energy utilization rate by utilizing the heat energy of the exhaust steam condensate, and improving the economical efficiency of the power plant.

Example 4

As shown in fig. 1, a circulating water pump 23 is provided between the water inlet pipe 24 and the water outlet pipe 22.

Specifically, the circulating water pump 23 provides the flowing pressure of the condensate of the heating network backwater and the steam exhaust device heating well 16 on the water inlet pipeline 24 and the water outlet pipeline 22.

Example 5

As shown in fig. 1-2, the heat pump solution is heated and evaporated by the driving steam entering the generator 2, and then condensed into condensed water, which enters the condensation tank 26. The condensate tank 26 communicates with the exhaust heat well 16.

Specifically, the generator 2 is connected with a condensation tank 26, and the steam after heat release and condensation entering the generator 2 is condensed into condensation water and is collected in the condensation tank 26. And the condensate tank 26 and the steam exhaust device heat well 16 can be communicated through a pipeline (not shown), and the condensate water and other two parts of exhaust steam condensate water are sent to a boiler system together for power generation and reuse.

Example 6

As shown in fig. 1-2, the absorption heat pump 1 further comprises a throttle valve 27, the throttle valve 27 is located between the generator 2 and the absorber 4, the concentrated solution in the generator 2 enters the absorber 4 through the throttle valve 27, low-pressure steam from the evaporator 7 is absorbed under the condition of low pressure, and heat is released in the process of steam absorption, and is transferred to the water inlet pipeline 24 for one-time heating. The refrigerant vapor in the generator 2 condenses in the condenser 9 to release heat, which is transferred to the water intake pipe 24 for secondary heating.

Specifically, the absorption heat pump 1 includes a generator 2, a solution heat exchanger 3, an absorber 4, a solution pump 5, a working medium pump 6, an evaporator 7, a throttle valve 27, and a condenser 9. The absorption heat pump 1 has two cycles, one is a solution cycle: the concentrated solution in the generator 2 enters the absorber 4 through the throttle valve 27, absorbs low-pressure steam from the evaporator 7 under the condition of low pressure, releases heat in the steam absorption process, and transmits the heat to the water inlet pipeline 24 for primary heating. And secondly, refrigerant circulation: the refrigerant vapor generated in the generator 2 condenses in the condenser 9 to release heat, which is transferred to the water intake pipe 24 for secondary heating.

The working mode and the principle of the utility model are as follows:

The system uses low-pressure steam of the low-pressure cylinder 11 of the steam turbine to enter the generator 2 as driving steam of the absorption heat pump 1, and part of exhaust steam enters the evaporator 7 for heat exchange, and heat supply network water can return to the water outlet pipeline 22 after passing through the absorber 4 and the condenser 9 in sequence for secondary heat exchange and temperature rise through the water inlet pipeline 24, so that the recovery and utilization of the vaporization latent heat of the exhaust steam are realized.

After the exhaust steam is subjected to heat release condensation through the evaporator 7 and cooling condensation through the gas condensation equipment, the condensate water has higher purity, the water temperature is about 42 ℃, and the system also collects the condensate water through the steam exhaust device thermal well 16 and returns the condensate water to the boiler system for power generation and use, so that the waste of water resources of a power plant is avoided, the heat energy of the exhaust steam condensate water is further utilized, and the energy utilization rate is improved.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model.

Claims (10)

1. An energy efficient heating system for a thermal power plant, comprising:

an absorption heat pump comprising a generator, an absorber, an evaporator and a condenser connected;

The low-pressure cylinder of the steam turbine is connected with a low-pressure steam inlet pipeline of the steam turbine, and the low-pressure steam inlet of the steam turbine enters the low-pressure cylinder of the steam turbine through the low-pressure steam inlet pipeline of the steam turbine to do work;

The low-pressure cylinder of the steam turbine is connected with a low-pressure cylinder steam extraction pipeline, and part of low-pressure steam enters the generator through the low-pressure cylinder steam extraction pipeline and is used as driving steam of the absorption heat pump;

The low-pressure cylinder of the steam turbine is connected with a first exhaust steam branch pipe, and part of exhaust steam enters condensing equipment through the first exhaust steam branch pipe and is cooled and condensed into condensate;

The low-pressure cylinder of the steam turbine is connected with a second exhaust steam branch pipe, and the other part of exhaust steam enters the evaporator through the second exhaust steam branch pipe, releases heat and condenses into condensate;

The exhaust steam condensate water passing through the condensing equipment enters the exhaust steam device hot well, the exhaust steam condensate water passing through the evaporator enters the exhaust steam device hot well through a drainage pipeline, and two parts of exhaust steam condensate water return to a boiler system through a condensation drainage pump for circulation;

The water inlet pipeline is sequentially connected with the absorber, the condenser and the water outlet pipeline to form a circulating pipeline; and the heat supply network water of the water inlet pipeline is subjected to heat exchange through the absorber to perform primary heating, and then subjected to heat exchange through the condenser to perform secondary heating.

2. An economizer heating system for a thermal power plant according to claim 1, further comprising a water supply pipe and a water return pipe, each in communication with a power plant heat supply network, the water supply pipe being connected to the water outlet pipe and the water return pipe being connected to the water inlet pipe.

3. An economizer heating system for a thermal power plant according to claim 1, wherein the exhaust means is connected with a condensate drain pump in the thermal well.

4. An economizer heating system for a thermal power plant according to claim 3 wherein two parts of exhaust steam condensed condensate are pumped to the boiler system by the condensed drain pump.

5. An economizer heating system for a thermal power plant according to claim 1, characterized in that a circulating water pump is arranged between the inlet conduit and the outlet conduit.

6. An economizer heating system for a thermal power plant according to claim 1 further comprising a condensate tank, wherein the drive steam entering the generator heats and evaporates the heat pump solution before condensing into condensate water entering the condensate tank.

7. An economizer heating system for a thermal power plant according to claim 6 wherein the condensate tank is in thermal communication with the exhaust device.

8. An economizer heating system for a thermal power plant according to claim 1 further comprising a throttle valve in the absorption heat pump, the throttle valve being located between the generator and the absorber, the concentrated solution in the generator passing through the throttle valve into the absorber, absorbing low pressure vapor from the evaporator at low pressure, releasing heat during vapor absorption, transferring heat to the inlet conduit for one heating.

9. An economizer heating system for a thermal power plant according to claim 1 wherein the refrigerant vapor in the generator condenses in the condenser to release heat, which is transferred to a water intake conduit for secondary heating.

10. An energy saving and heating system for a thermal power plant according to claim 1, wherein the condensing equipment is an air cooling island.