A heat storage peak regulation system and method of low-pressure steam supply combined with intermediate condensing

Abstract

The application discloses a heat storage peak regulation system of low-pressure steam supply combined with middle-pressure exhaust condensate, which comprises a high-temperature heat storage tank, a low-temperature heat storage tank, a heat exchange unit and a condenser, and the middle-pressure cylinder exhaust of a steam turbine is delivered to the heat exchange unit, and the working medium is heated with the middle-pressure cylinder exhaust and then enters the high-temperature heat storage tank, the heat of the middle-pressure cylinder exhaust is stored in the high-temperature heat storage tank, and the heat in the high-temperature heat storage tank is used for external low-pressure steam supply, the heat distribution of the heat storage tank is used to realize the purpose of enhancing the stability of the unit for external low-pressure steam supply, and compared with the traditional steam turbine and low-pressure steam supply system, the unit has the characteristics of fast load response speed, stable steam supply and flexible operation regulation mode.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of steam turbines, and relates to a heat storage peak regulation system and method for low-pressure steam supply of medium-pressure joint condensate water. BACKGROUND

[0002] With the change of power grid power structure, the requirement of the power grid on the peak regulation capacity of thermal power generating units is increasing, and heat supply units are also widely included in the range of peak regulation. The operation load of external steam supply units is generally restricted by parameters such as steam supply pressure and flow, and the stability of steam supply parameters and steam supply capacity cannot be guaranteed when the load is low or the load changes rapidly, which affects the steam supply stability of external heat supply units, and affects the peak regulation depth and load response speed of the units when a large amount of external steam is supplied, and it is difficult to achieve a good level. Meanwhile, the characteristics such as large thermal inertia of the boiler itself also cause the load response speed of the heat supply unit to be slow. SUMMARY

[0003] The application aims to solve the problems in the prior art, and provides a heat storage peak regulation system and method for low-pressure steam supply of medium-pressure joint condensate water.

[0004] To achieve the above-mentioned purpose, the application adopts the following technical solutions:

[0005] A heat storage peak regulation system for low-pressure steam supply of medium-pressure joint condensate water, comprising a high-temperature heat storage tank, a low-temperature heat storage tank, a first heat exchange unit, a second heat exchange unit, a medium-pressure cylinder of a steam turbine and a condenser.

[0006] The outlet of the high-temperature heat storage tank is connected to the hot side inlet of the second heat exchange unit, the cold side outlet of the second heat exchange unit is an output heat supply steam outlet, the hot side outlet of the second heat exchange unit is connected to the low-temperature heat storage tank, the outlet of the condenser is connected to the cold side inlet of the second heat exchange unit, the outlet of the low-temperature heat storage tank is connected to the cold side inlet of the first heat exchange unit, the cold side outlet of the first heat exchange unit is connected to the high-temperature heat storage tank, and the outlet of the medium-pressure cylinder of the steam turbine is connected to the hot side inlet of the first heat exchange unit.

[0007] Further improvements of the application are as follows:

[0008] A first conveying unit is installed between the high-temperature heat storage tank and the second heat exchange unit, and a second conveying unit is installed between the low-temperature heat storage tank and the first heat exchange unit.

[0009] The first conveying unit is a high-temperature molten salt pump, and the second conveying unit is a low-temperature molten salt pump.

[0010] The outlet of the condenser is further connected to a condensate pump and a low-pressure heater in sequence.

[0011] A booster pump is installed between the condenser and the second heat exchange unit.

[0012] The hot side outlet of the first heat exchange unit is connected to the deaerator through a drain pump.

[0013] The outlet of the intermediate pressure cylinder of the steam turbine is also connected to a low pressure cylinder of the steam turbine.

[0014] The first heat exchange unit is a heat storage heat exchanger, and the second heat exchange unit is a heat storage heat exchanger.

[0015] A regulating method of a heat storage peak regulation system of a low pressure steam supply combined with intermediate condensate water, comprising,

[0016] When the low pressure heat supply steam demand increases, the flow of the first conveying unit and the booster pump is increased, the heat exchange amount of the second heat exchange unit is increased, and the output of the heat supply steam is increased.

[0017] When the low pressure heat supply steam demand decreases, the flow of the first conveying unit and the booster pump is decreased, the heat exchange amount of the second heat exchange unit is decreased, and the output of the heat supply steam is decreased.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] The present application sets up high temperature heat storage tanks, low temperature heat storage tanks, heat exchange units and condensers and other equipment, and the steam turbine intermediate pressure cylinder exhaust steam is conveyed to the heat exchange unit, the working medium exchanges heat with the intermediate pressure cylinder exhaust steam and then enters the high temperature heat storage tank, the heat of the intermediate pressure cylinder exhaust steam is stored in the high temperature heat storage tank, the heat in the high temperature heat storage tank is used for external low pressure steam supply, and the heat distribution of the heat storage tank is used to realize the purpose of enhancing the stability of the unit external low pressure steam supply. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0021] Figure 1 The figure is a schematic diagram of the system structure of the present application.

[0022] Wherein: 1-high temperature heat storage tank, 2-low temperature heat storage tank, 3-first heat exchange unit, 4-second heat exchange unit, 5-first conveying unit, 6-second conveying unit, 7-condensate pump, 8-low pressure heater, 9- booster pump, 10-steam turbine intermediate pressure cylinder, 11-steam turbine low pressure cylinder, 12-drain pump, 13-condenser. DETAILED DESCRIPTION

[0023] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0025] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0026] In the description of the embodiments of the present application, it should be noted that, if the orientation or position relationship indicated by the terms "upper", "lower", "horizontal", "inner" and the like is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship when the product of the present application is usually placed, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0027] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0028] In the description of the embodiments of the present application, it should also be noted that, unless otherwise explicitly specified and limited, if the terms "arrangement", "installation", "connection", "connection" appear, they should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, can be electrically connected; can be directly connected, can be indirectly connected through an intermediate medium, or can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] The present application will be described in further detail below with reference to the drawings:

[0030] Referring toFigure 1 The system structure schematic diagram of the present application, including high temperature heat storage tank 1, low temperature heat storage tank 2, first heat exchange unit 3, second heat exchange unit 4, first conveying unit 5, second conveying unit 6, condensate pump 7, low pressure heater 8, booster pump 9, steam turbine intermediate pressure cylinder 10, steam turbine low pressure cylinder 11, drain pump 12 and condenser 13, the outlet of high temperature heat storage tank 1 is connected with the hot side inlet of second heat exchange unit 4 through first conveying unit 5, the cold side outlet of second heat exchange unit 4 is the output heat supply steam outlet, the hot side outlet of second heat exchange unit is connected with low temperature heat storage tank 2, the outlet of condenser 13 is connected with the cold side inlet of second heat exchange unit 4 through booster pump 9, the outlet of low temperature heat storage tank 2 is connected with the cold side inlet of first heat exchange unit 3 through second conveying unit 6, the cold side outlet of first heat exchange unit 3 is connected with high temperature heat storage tank 1, the hot side outlet of first heat exchange unit 3 is connected with deaerator through drain pump 12, the outlet of steam turbine intermediate pressure cylinder 10 is connected with the hot side inlet of first heat exchange unit 3, the outlet of condenser 13 is also connected with condensate pump 7 and low pressure heater 8 in turn, the outlet of steam turbine intermediate pressure cylinder 10 is also connected with the inlet of steam turbine low pressure cylinder 11. Wherein, first heat exchange unit 3 is a heat accumulating heat exchanger, second heat exchange unit 4 is a heat storage heat exchanger, first conveying unit 5 is a high temperature molten salt pump, and second conveying unit 6 is a low temperature molten salt pump.

[0031] The specific working process is as follows:

[0032] The low temperature molten salt is conveyed from the outlet of low temperature heat storage tank 2 to the heat accumulating heat exchanger by low temperature molten salt pump, and becomes high temperature molten salt after heat exchange with the steam exhaust of steam turbine intermediate pressure cylinder, and then enters high temperature heat storage tank 1. The high temperature molten salt is conveyed from the outlet of high temperature heat storage tank 1 to the heat storage heat exchanger by high temperature molten salt pump, and the water in condenser 13 is pressurized by booster pump 9 and then sent to the heat storage heat exchanger, and becomes low pressure heat supply steam after heat exchange with the high temperature molten salt, and then is supplied to the outside. Part of heat is always stored in high temperature heat storage tank 1, and the heat accumulating heat is from the steam exhaust of steam turbine intermediate pressure cylinder. When the demand of low pressure heat supply steam of users increases, the flow of low pressure heat supply steam is increased by controlling the flow of high temperature molten salt pump and booster pump 9. When the demand of low pressure heat supply steam of users decreases, the flow of low pressure heat supply steam is decreased by controlling the flow of high temperature molten salt pump and booster pump 9.

[0033] When the unit needs to rapidly increase load, the flow of steam exhaust of steam turbine intermediate pressure cylinder into the heat accumulating heat exchanger rapidly decreases, at this time, the amount of steam exhaust of steam turbine intermediate pressure cylinder into steam turbine low pressure cylinder increases, and the output of the unit can rapidly increase. When the unit needs to rapidly decrease load, the flow of steam exhaust of steam turbine intermediate pressure cylinder into the heat accumulating heat exchanger rapidly increases, at this time, the amount of steam exhaust of steam turbine intermediate pressure cylinder into steam turbine low pressure cylinder decreases, and the output of the unit can rapidly decrease. The heat of low pressure heat supply steam to the outside comes from high temperature heat storage tank 1, and since part of heat is always stored in high temperature heat storage tank 1, the supply of steam to the outside is no longer restricted by the depth and speed of unit peak shaving, thereby improving the stability of steam supply to the outside.

[0034] The above merely provides the preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall fall within the scope of protection of the present application.

Claims

1. A method for regulating a thermal storage and peak-shaving system based on low-pressure steam supply from combined condensate drainage, the method being characterized in that, It includes a high-temperature heat storage tank (1), a low-temperature heat storage tank (2), a first heat exchange unit (3), a second heat exchange unit (4), a steam turbine intermediate pressure cylinder (10), and a condenser (13). The outlet of the high-temperature heat storage tank (1) is connected to the hot-side inlet of the second heat exchange unit (4), the cold-side outlet of the second heat exchange unit (4) is the outlet for output heating steam, the hot-side outlet of the second heat exchange unit (4) is connected to the low-temperature heat storage tank (2), the outlet of the condenser (13) is connected to the cold-side inlet of the second heat exchange unit (4), the outlet of the low-temperature heat storage tank (2) is connected to the cold-side inlet of the first heat exchange unit (3), the cold-side outlet of the first heat exchange unit (3) is connected to the high-temperature heat storage tank (1), and the outlet of the intermediate-pressure cylinder (10) of the steam turbine is connected to the hot-side inlet of the first heat exchange unit (3); the outlet of the intermediate-pressure cylinder (10) of the steam turbine is also connected to the low-pressure cylinder (11) of the steam turbine; the first heat exchange unit (3) is a heat storage heat exchanger, and the second heat exchange unit (4) is a heat storage heat exchanger; the method is characterized in that it includes, The demand for low-pressure heating steam increases, which increases the flow rate of the first conveying unit (5) and the booster pump (9), increases the heat exchange capacity of the second heat exchange unit (4), and increases the output of heating steam. The demand for low-pressure heating steam is reduced, the flow rate of the first conveying unit (5) and the booster pump (9) is reduced, the heat exchange capacity of the second heat exchange unit (4) is reduced, and the output heating steam volume is reduced. When the unit needs to rapidly increase the load, the flow rate of steam discharged from the intermediate pressure cylinder of the steam turbine into the heat storage heat exchanger decreases rapidly. At this time, the amount of steam discharged from the intermediate pressure cylinder into the low pressure cylinder of the steam turbine increases, and the unit output can be rapidly increased. When the unit needs to reduce load quickly, the flow rate of steam discharged from the intermediate pressure cylinder of the turbine into the heat storage heat exchanger increases rapidly. At this time, the amount of steam discharged from the intermediate pressure cylinder into the low pressure cylinder of the turbine decreases, and the unit output can be reduced rapidly.

2. The regulation method of a thermal storage and peak-shaving system for low-pressure steam supply of combined condensate drainage as described in claim 1, characterized in that, A first conveying unit (5) is installed between the high-temperature heat storage tank (1) and the second heat exchange unit (4), and a second conveying unit (6) is installed between the low-temperature heat storage tank (2) and the first heat exchange unit (3).

3. The regulation method of a thermal storage and peak-shaving system for low-pressure steam supply of combined condensate drainage as described in claim 2, characterized in that, The first conveying unit (5) is a high-temperature molten salt pump, and the second conveying unit (6) is a low-temperature molten salt pump.

4. The regulation method of a thermal storage and peak-shaving system for low-pressure steam supply of combined condensate drainage as described in claim 1, characterized in that, The outlet of the condenser (13) is also connected in sequence to a condensate pump (7) and a low-pressure heater (8).

5. The regulation method of a thermal storage and peak-shaving system for low-pressure steam supply of combined condensate drainage as described in claim 1, characterized in that, A booster pump (9) is installed between the condenser (13) and the second heat exchange unit (4).

6. The regulation method of a thermal storage and peak-shaving system for low-pressure steam supply of combined condensate drainage as described in claim 1, characterized in that, The hot-side outlet of the first heat exchange unit (3) is connected to the deaerator via a condensate pump (12).

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