阅读说明：本技术 一种轴封溢流蒸汽驱动的吸收式热泵余热回收装置及方法 (Shaft seal overflow steam driven absorption heat pump waste heat recovery device and method ) 是由 王涛 令彤彤 刘世雄 刘继锋 刘岗 顿小宝 李洲 宋晓辉 于 2020-06-29 设计创作，主要内容包括：本发明公开了一种轴封溢流蒸汽驱动的吸收式热泵余热回收装置及方法,包括汽轮机、轴封溢流蒸汽管道、凝汽器、吸收式热泵发生器、吸收式热泵冷凝器、吸收式热泵蒸发器、水-水换热器、疏水管道、吸收式热泵吸收器、溶液热交换器、凝结水出水截止阀、凝结水管路及冷却塔,该装置及方法采用汽轮机轴封溢流蒸汽作为驱动热源,且能够对间冷系统循环水余热进行回收,将热量传递给凝结水系统,机组经济性较高。(The invention discloses a shaft seal overflow steam driven absorption heat pump waste heat recovery device and a method, which comprises a steam turbine, a shaft seal overflow steam pipeline, a condenser, an absorption heat pump generator, an absorption heat pump condenser, an absorption heat pump evaporator, a water-water heat exchanger, a drain pipeline, an absorption heat pump absorber, a solution heat exchanger, a condensed water outlet stop valve, a condensed water pipeline and a cooling tower.)

1. The shaft seal overflow steam driven absorption heat pump waste heat recovery device is characterized by comprising a steam turbine (1), a shaft seal overflow steam pipeline (2), a condenser (3), an absorption heat pump generator (4), an absorption heat pump condenser (5), an absorption heat pump evaporator (6), a water-water heat exchanger (13), a drain pipeline (14), an absorption heat pump absorber (7), a solution heat exchanger (8), a condensed water outlet stop valve (20), a condensed water pipeline and a cooling tower (21);

an outlet of the steam turbine (1) is communicated with an inlet of a shaft seal overflow steam pipeline (2), an outlet of the shaft seal overflow steam pipeline (2) is communicated with a driving heat source inlet of an absorption heat pump generator (4) and an inlet of a condenser (3), a driving heat source outlet of the absorption heat pump generator (4) is communicated with a driving heat source inlet of a water-water heat exchanger (13), and a driving heat source outlet of the water-water heat exchanger (13) is communicated with an inlet of the condenser (3) through a drain pipeline (14);

the exhaust steam outlet of the steam turbine (1) is communicated with the inlet of the condenser (3), the condensed water outlet of the condenser (3) is divided into two paths, one path is communicated with the condensed water inlet of the absorption heat pump absorber (7), the condensed water outlet of the absorption heat pump absorber (7) is communicated with the condensed water inlet of the absorption heat pump condenser (5), the condensed water outlet of the absorption heat pump condenser (5) is communicated with the condensed water inlet of the water-water heat exchanger (13), the condensed water outlet of the water-water heat exchanger (13) is communicated with the condensed water pipeline through a condensed water outlet stop valve (20), and the other path is communicated with the condensed water pipeline;

a steam outlet of the absorption heat pump generator (4) is communicated with a steam inlet of the absorption heat pump condenser (5), a steam outlet of the absorption heat pump condenser (5) is communicated with a steam inlet of the absorption heat pump evaporator (6), a steam outlet of the absorption heat pump evaporator (6) is communicated with an inlet of the absorption heat pump absorber (7), and a circulating working medium side of the absorption heat pump generator (4) and a circulating working medium of the absorption heat pump absorber (7) exchange heat through a solution heat exchanger (8);

the circulating water outlet of the condenser (3) is communicated with the circulating water inlet of the absorption heat pump evaporator (6) and the circulating water inlet of the cooling tower (21), and the circulating water inlet of the condenser (3) is communicated with the circulating water outlet of the absorption heat pump evaporator (6) and the outlet of the cooling tower (21).

2. The shaft seal overflow steam driven absorption heat pump waste heat recovery device according to claim 1, characterized in that a circulating water outlet of the condenser (3) is communicated with a circulating water inlet of the absorption heat pump evaporator (6) through a water inlet pipeline (11);

the circulating water inlet of the condenser (3) is communicated with the circulating water outlet of the absorption heat pump evaporator (6) through a water return pipeline (12).

3. The shaft seal overflow steam driven absorption heat pump waste heat recovery device according to claim 1, wherein the outlet of the shaft seal overflow steam pipeline (2) is communicated with the driving heat source inlet of the absorption heat pump generator (4) through a generator steam inlet regulating valve (9);

the outlet of the shaft seal overflow steam pipeline (2) is communicated with the inlet of the condenser (3) through a shaft seal overflow bypass regulating valve (10).

4. The shaft seal overflow steam driven absorption heat pump waste heat recovery device according to claim 1, characterized in that a condensed water inlet adjusting valve (18) is arranged between a condensed water outlet of the condenser (3) and a condensed water inlet of the absorption heat pump absorber (7);

a condensed water bypass regulating valve (19) is arranged between the condensed water outlet of the condenser (3) and the condensed water pipeline.

5. The shaft seal overflow steam driven absorption heat pump waste heat recovery device according to claim 2, characterized in that the water inlet pipeline (11) is provided with a circulating water inlet stop valve (16), and the water return pipeline (12) is provided with a circulating water outlet stop valve (17).

6. The shaft seal overflow steam driven absorption heat pump waste heat recovery device according to claim 1, characterized in that a drain regulating valve (15) is arranged on the drain pipeline (14).

7. The shaft seal overflow steam driven absorption heat pump waste heat recovery device according to claim 1, wherein the steam outlet of the absorption heat pump condenser (5) is communicated with the steam inlet of the absorption heat pump evaporator (6) through a throttle valve.

8. The shaft seal overflow steam driven absorption heat pump waste heat recovery method is characterized in that the shaft seal overflow steam driven absorption heat pump waste heat recovery device based on any one of claims 1 to 7 comprises the following steps:

in the starting stage of the unit, firstly putting a circulating water and condensate system into operation, when the load of the unit is increased, opening a generator steam inlet adjusting valve 9, driving steam to enter an absorption heat pump generator 4, and enabling an absorption heat pump system to enter a working state; in an accident state, closing the generator steam inlet regulating valve 9, opening the shaft seal overflow bypass regulating valve 10, completing the shutdown operation of the absorption heat pump system, and keeping the pressure of a shaft seal main pipe stable; in the maintenance state, the driving heat source system is isolated through the generator steam inlet regulating valve 9 and the drainage regulating valve 15; the isolation of the circulating water system is completed through a circulating water inlet stop valve 16 and a circulating water outlet stop valve 17; the isolation of the condensate system is accomplished by the condensate inlet regulating valve 18 and the condensate outlet shutoff valve 20.

Technical Field

The invention belongs to the technical field of waste heat recovery and utilization of power plants, and relates to a shaft seal overflow steam driven absorption heat pump waste heat recovery device and method.

Background

The shaft seal system is an important system for keeping the vacuum of the condenser and the safe operation of the steam turbine. In the load-increasing process of the steam turbine, the steam inlet flow of the high-pressure cylinder is increased, the shaft seal steam source is gradually transited to the high-pressure cylinder steam seal steam leakage through the auxiliary steam supply, and the self-sealing effect is achieved. Meanwhile, the system is provided with a shaft seal steam overflow pipeline which discharges redundant steam to the condenser. In recent years, large-capacity and high-parameter units are put into operation in various places throughout the country, the steam parameters of the newly-built units reach 28MPa/600 ℃/620 ℃, the shaft seal overflow steam parameters are improved along with the steam parameters, and the obvious working medium and heat loss is caused when the shaft seal overflow steam parameters are directly discharged to a condenser. How to utilize shaft seal overflow steam with higher steam quality becomes a subject of waste heat utilization of a power plant.

In northern areas of China, due to the shortage of water resources and high working reliability of the surface condenser, a Hamon type indirect air cooling system adopting the surface condenser is becoming a main choice for exhaust steam cooling of a steam turbine of a large-scale thermal power plant. The indirect cooling system adopts closed circulation, so that the consumption of water resources is reduced, and the heat exchange effect has natural disadvantage compared with a wet cooling system. Especially under summer working condition, the inlet water temperature of the indirect cooling system can reach about 60 ℃, the design backpressure is 10-15 kPa higher than that of a similar wet cooling unit, and the cold end loss of the unit is higher. At present, the utilization of the circulating water waste heat of an indirect cooling system mainly aims at a unit with heat supply requirements, steam extracted by a steam turbine is used as a driving heat source, and the circulating water waste heat is used for heating in winter by an absorption heat pump unit. This method of utilization has a great limitation, and for non-heating units, this part of energy is not fully utilized. And the steam extraction of the steam turbine is used as a driving heat source, so that the thermal cycle efficiency of the unit is influenced, and the unit has poor economy.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a shaft seal overflow steam driven absorption heat pump waste heat recovery device and a shaft seal overflow steam driven absorption heat pump waste heat recovery method.

In order to achieve the aim, the shaft seal overflow steam driven absorption heat pump waste heat recovery device comprises a steam turbine, a shaft seal overflow steam pipeline, a condenser, an absorption heat pump generator, an absorption heat pump condenser, an absorption heat pump evaporator, a water-water heat exchanger, a drain pipeline, an absorption heat pump absorber, a solution heat exchanger, a condensed water outlet stop valve, a condensed water pipeline and a cooling tower, wherein the shaft seal overflow steam pipeline is connected with the absorption heat pump evaporator;

the outlet of the steam turbine is communicated with the inlet of the shaft seal overflow steam pipeline, the outlet of the shaft seal overflow steam pipeline is communicated with the driving heat source inlet of the absorption heat pump generator and the inlet of the condenser, the driving heat source outlet of the absorption heat pump generator is communicated with the driving heat source inlet of the water-water heat exchanger, and the driving heat source outlet of the water-water heat exchanger is communicated with the inlet of the condenser through a drain pipeline;

the exhaust steam outlet of the steam turbine is communicated with the inlet of a condenser, the condensed water outlet of the condenser is divided into two paths, one path is communicated with the condensed water inlet of an absorption heat pump absorber, the condensed water outlet of the absorption heat pump absorber is communicated with the condensed water inlet of the absorption heat pump condenser, the condensed water outlet of the absorption heat pump condenser is communicated with the condensed water inlet of a water-water heat exchanger, the condensed water outlet of the water-water heat exchanger is communicated with the condensed water pipeline through a condensed water outlet stop valve, and the other path is communicated with the condensed water pipeline;

the steam outlet of the absorption heat pump generator is communicated with the steam inlet of the absorption heat pump condenser, the steam outlet of the absorption heat pump condenser is communicated with the steam inlet of the absorption heat pump evaporator, the steam outlet of the absorption heat pump evaporator is communicated with the inlet of the absorption heat pump absorber, and the circulating working medium side of the absorption heat pump generator exchanges heat with the circulating working medium of the absorption heat pump absorber through a solution heat exchanger;

and the circulating water inlet of the condenser is communicated with the circulating water outlet of the absorption heat pump evaporator and the outlet of the cooling tower.

The circulating water outlet of the condenser is communicated with the circulating water inlet of the absorption heat pump evaporator through a water inlet pipeline;

and a circulating water inlet of the condenser is communicated with a circulating water outlet of the absorption heat pump evaporator through a water return pipeline.

The outlet of the shaft seal overflow steam pipeline is communicated with the driving heat source inlet of the absorption heat pump generator through a generator steam inlet regulating valve;

the outlet of the shaft seal overflow steam pipeline is communicated with the inlet of the condenser through a shaft seal overflow bypass regulating valve.

A condensed water inlet adjusting valve is arranged between the condensed water outlet of the condenser and the condensed water inlet of the absorption heat pump absorber;

and a condensed water bypass regulating valve is arranged between a condensed water outlet of the condenser and the condensed water pipeline.

The water inlet pipeline is provided with a circulating water inlet stop valve, and the water return pipeline is provided with a circulating water outlet stop valve.

The drain pipeline is provided with a drain regulating valve.

The steam outlet of the absorption heat pump condenser is communicated with the steam inlet of the absorption heat pump evaporator through a throttle valve.

The shaft seal overflow steam driven absorption heat pump waste heat recovery method comprises the following steps:

in the starting stage of the unit, firstly putting a circulating water and condensate system into operation, when the load of the unit is increased, opening a generator steam inlet regulating valve, driving steam to enter an absorption heat pump generator, and enabling the absorption heat pump system to enter a working state; in an accident state, closing the steam inlet regulating valve of the generator, opening the shaft seal overflow bypass regulating valve, completing the shutdown operation of the absorption heat pump system, and keeping the pressure of a shaft seal main pipe stable; under the maintenance state, the driving heat source system is isolated through the steam inlet regulating valve and the drainage regulating valve of the generator; the isolation of the circulating water system is completed through a circulating water inlet stop valve and a circulating water outlet stop valve; the isolation of the condensed water system is completed through the condensed water inlet regulating valve and the condensed water outlet stop valve.

The invention has the following beneficial effects:

when the device and the method for recovering the waste heat of the absorption heat pump driven by the shaft seal overflow steam are in specific operation, the shaft seal overflow steam is adopted to drive the absorption heat pump, the exhausted high-temperature circulating water heat output by a condenser is recovered, the obtained heat is sent to a condensate system to heat condensate water for the first time, and the high-temperature saturated water after the heat release of the shaft seal overflow steam carries out secondary heating on the condensate water in a water-water heat exchanger, so that the recovery and the utilization of the shaft seal overflow steam and the waste heat of the circulating water are realized. After the circulating water system extracts a part of heat, the heat dissipation load of the indirect cooling system is reduced, the back pressure of the unit is reduced, and meanwhile, the recovered heat is used for heating condensed water so as to improve the economy of the unit.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Wherein, 1 is a steam turbine, 2 is a shaft seal overflow steam pipeline, 3 is a condenser, 4 is an absorption heat pump generator, 5 is an absorption heat pump condenser, 6 is an absorption heat pump evaporator, 7 is an absorption heat pump absorber, 8 is a solution heat exchanger, 9 is a generator steam inlet regulating valve, 10 is a shaft seal overflow bypass regulating valve, 11 is a circulating water to absorption heat pump evaporator water inlet pipeline, 12 is a water return pipeline, 13 is a water-water heat exchanger, 14 is a drain pipeline, 15 is a drain regulating valve, 16 is a circulating water inlet stop valve, 17 is a circulating water outlet stop valve, 18 is a condensed water inlet regulating valve, 19 is a condensed water bypass regulating valve, 20 is a condensed water outlet stop valve, and 21 is a cooling tower.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

referring to fig. 1, the shaft seal overflow steam driven absorption heat pump waste heat recovery device of the present invention includes a steam turbine 1, a shaft seal overflow steam pipeline 2, a condenser 3, an absorption heat pump generator 4, an absorption heat pump condenser 5, an absorption heat pump evaporator 6, a water-water heat exchanger 13, a drain pipeline 14, an absorption heat pump absorber 7, a solution heat exchanger 8, a condensed water outlet stop valve 20, a condensed water pipeline, and a cooling tower 21; an outlet of the steam turbine 1 is communicated with an inlet of a shaft seal overflow steam pipeline 2, an outlet of the shaft seal overflow steam pipeline 2 is communicated with a driving heat source inlet of an absorption heat pump generator 4 and an inlet of a condenser 3, a driving heat source outlet of the absorption heat pump generator 4 is communicated with a driving heat source inlet of a water-water heat exchanger 13, and a driving heat source outlet of the water-water heat exchanger 13 is communicated with an inlet of the condenser 3 through a drain pipeline 14; the exhaust steam outlet of the steam turbine 1 is communicated with the inlet of the condenser 3, the condensed water outlet of the condenser 3 is divided into two paths, one path is communicated with the condensed water inlet of the absorption heat pump absorber 7, the condensed water outlet of the absorption heat pump absorber 7 is communicated with the condensed water inlet of the absorption heat pump condenser 5, the condensed water outlet of the absorption heat pump condenser 5 is communicated with the condensed water inlet of the water-water heat exchanger 13, the condensed water outlet of the water-water heat exchanger 13 is communicated with the condensed water pipeline through a condensed water outlet stop valve 20, and the other path is communicated with the condensed water pipeline; a steam outlet of the absorption heat pump generator 4 is communicated with a steam inlet of the absorption heat pump condenser 5, a steam outlet of the absorption heat pump condenser 5 is communicated with a steam inlet of the absorption heat pump evaporator 6, a steam outlet of the absorption heat pump evaporator 6 is communicated with an inlet of the absorption heat pump absorber 7, and a cycle medium side of the absorption heat pump generator 4 exchanges heat with a cycle medium of the absorption heat pump absorber 7 through a solution heat exchanger 8; the circulating water outlet of the condenser 3 is communicated with the circulating water inlet of the absorption heat pump evaporator 6 and the circulating water inlet of the cooling tower 21, and the circulating water inlet of the condenser 3 is communicated with the circulating water outlet of the absorption heat pump evaporator 6 and the outlet of the cooling tower 21. The circulating water outlet of the condenser 3 is communicated with the circulating water inlet of the absorption heat pump evaporator 6 through a water inlet pipeline 11; and a circulating water inlet of the condenser 3 is communicated with a circulating water outlet of the absorption heat pump evaporator 6 through a water return pipeline 12, wherein a circulating water inlet stop valve 16 is arranged on the water inlet pipeline 11, and a circulating water outlet stop valve 17 is arranged on the water return pipeline 12.

A condensed water inlet adjusting valve 18 is arranged between the condensed water outlet of the condenser 3 and the condensed water inlet of the absorption heat pump absorber 7; a condensed water bypass regulating valve 19 is arranged between the condensed water outlet of the condenser 3 and the condensed water pipeline.

A drain regulating valve 15 is arranged on the drain pipeline 14, and the outlet of the shaft seal overflow steam pipeline 2 is communicated with the driving heat source inlet of the absorption heat pump generator 4 through a generator steam inlet regulating valve 9; the outlet of the shaft seal overflow steam pipeline 2 is communicated with the inlet of the condenser 3 through a shaft seal overflow bypass regulating valve 10; the steam outlet of the absorption heat pump condenser 5 is communicated with the steam inlet of the absorption heat pump evaporator 6 through a throttle valve.

The shaft seal overflow steam driven absorption heat pump waste heat recovery method comprises the following steps:

in the starting stage of the unit, the circulating water and the condensate system are firstly put into operation, when the load of the unit is increased, the generator steam inlet adjusting valve 9 is opened, the driving steam enters the absorption heat pump generator 4, the absorption heat pump system enters the working state, in the accident state, the generator steam inlet adjusting valve 9 is closed, the shaft seal overflow bypass adjusting valve 10 is opened, the stopping work of the absorption heat pump system is completed, the pressure of a main pipe of the shaft seal is kept stable, and in the maintenance state, the driving heat source system is isolated through the generator steam inlet adjusting valve 9 and the drain adjusting valve 15; the isolation of the circulating water system is completed through a circulating water inlet stop valve 16 and a circulating water outlet stop valve 17; the isolation of the condensate system is accomplished by the condensate inlet regulating valve 18 and the condensate outlet shutoff valve 20.

Compared with the prior art, the invention does not supply heat to the outside, can be widely used for non-heat supply units, can be used for newly building units, can also be used for modifying the existing units, and can stably operate when the load of the units changes or the environmental temperature changes by adjusting the overflow flow of the shaft seal steam and the flow of circulating water.