A generator set sharing type peak regulation system and working method

Abstract

The application discloses a generator set shared peak regulation system and a working method thereof. The system comprises a steam generator, a steam power generation device, a heat recovery device, a generator, an energy storage switch, a water taking shutoff valve, a backwater regulating valve, a molten salt cold tank, a cold molten salt pump, a molten salt electric heater, a hot molten salt tank, a hot molten salt pump, a feedwater heater inlet shutoff valve, a feedwater heater, a feedwater heater outlet shutoff valve, a heat network water heater inlet shutoff valve, a heat network water heater, a heat network water heater outlet regulating valve and a heat network water taking shutoff valve. The application realizes the peak regulation of two or more generators by one peak regulation system, is a shared energy storage system, uses a heat storage medium such as molten salt to realize large-capacity, long-time and high-quality energy storage, realizes the deep peak regulation of the unit, and the heat energy has diversified uses. The application can realize the flexible transformation of the whole plant through single investment, and has high equipment utilization.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energy storage, and particularly relates to a generator set shared type peak regulation system and a working method. BACKGROUND

[0002] With the continuous improvement of environmental protection targets, higher requirements are put forward for the flexibility of coal-fired generating units. In order to further improve the flexibility and regulation capacity and promote the clean and low-carbon transformation of the power industry, the coal-fired generating units need to be upgraded. The upgrading scheme of coal-fired generating units makes clear requirements for the peak regulation capacity of the units. The general requirement for the peak regulation capacity of the pure condensing condition is that the minimum power generation output reaches 35% of the rated load. The heating and power generating unit needs to strive to achieve a minimum power generation output of 40% of the rated load for 6 hours a day during the heating period through thermal and power decoupling. Other types of units should take measures to reduce the minimum power generation output as much as possible.

[0003] Due to the large basic capacity of thermal power generating units, a large amount of high-quality energy needs to be stored during deep peak regulation. The existing electrochemical energy storage, hot water tank energy storage, and steam extraction energy storage cannot meet the requirements of deep peak regulation of thermal power generating units. Reducing the online power can quickly and deeply achieve deep peak regulation of thermal power generating units, and it is particularly important to store electrical energy as high-quality energy. Molten salt thermal storage is suitable for deep peak regulation of thermal power generating units due to its large capacity and high thermal energy grade. Molten salt thermal storage is a kind of inorganic salt sensible heat storage, which stores heat by changing the temperature of molten salt, and usually uses a double-tank molten salt thermal storage system. Molten salt thermal storage is mostly applied to solar thermal power stations, and there are few applications of molten salt thermal storage peak regulation systems in large-scale generating units.

[0004] Power plants are composed of two or more generating units operating in parallel. The existing conventional flexibility upgrading technology is for a single generating unit, and multiple generating units require multiple investments, which is high in investment cost, low in equipment utilization rate, and low in investment return rate. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a generating unit shared type peak regulation system and a working method. The system realizes peak regulation of two or more generating units through one peak regulation system, which is a shared energy storage system, and can reduce the investment cost.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0007] A generating unit shared type peak regulation system, comprising a peak regulation system and at least two groups of generating units, the generating unit comprising a steam generator, a steam power generation device, a heat recovery device, and a generator, the steam outlet of the steam generator being connected with the steam inlet of the steam power generation device, the steam outlet of the steam power generation device being connected with the cold inlet of the heat recovery device, the cold outlet of the heat recovery device being communicated with the inner cavity of the steam generator, and the steam power generation device being connected with the generator.

[0008] The peak shaving system comprises, in sequence, a molten salt cold tank, a cold molten salt pump, a molten salt electric heater, a molten salt hot tank, a hot molten salt pump and a feed water heater, the inlet of the cold molten salt pump is connected with the outlet of the molten salt cold tank, the outlet of the cold molten salt pump is connected with the inlet of the molten salt electric heater, the outlet of the molten salt electric heater is connected with the inlet of the molten salt hot tank, the inlet of the hot molten salt pump is connected with the outlet of the molten salt hot tank, the outlet of the hot molten salt pump is connected with the hot inlet of the feed water heater, and the hot outlet of the feed water heater is connected with the inlet of the molten salt cold tank.

[0009] The generators of all the generator sets are electrically connected with the molten salt electric heater, and an energy storage switch is arranged on the connecting line.

[0010] The cold outlet of the feed water heater is connected with the hot inlets of the regenerative devices of all the generator sets, and the hot outlets of the regenerative devices of all the generator sets are connected with the cold inlets of the feed water heater.

[0011] Valves are arranged at the hot inlets of the regenerative devices of all the generator sets, the hot outlets of the regenerative devices of all the generator sets, the cold outlet of the feed water heater and the cold inlets of the feed water heater.

[0012] Preferably, the shared peak shaving system of the generator set further comprises a heat network water heater, the hot inlet of the heat network water heater is connected with the outlet of the hot molten salt pump, the hot outlet of the heat network water heater is connected with the inlet of the molten salt cold tank, and the hot outlet and the hot inlet of the heat network water heater are respectively provided with a heat network water heater outlet regulating valve and a heat network water heater inlet shut-off valve.

[0013] Preferably, the cold inlet and the cold outlet of the heat network water heater are respectively provided with a heat network backwater regulating valve and a heat network water taking shut-off valve.

[0014] Preferably, the molten salt cold tank and the hot molten salt pump adopt double-tank energy storage or use a single-tank energy storage with a temperature gradient.

[0015] Preferably, liquid level meters, thermometers and pressure gauges are arranged on the molten salt cold tank and the molten salt hot tank.

[0016] Preferably, the molten salt electric heater adopts a resistance type, an electromagnetic type or an electrode type molten salt electric heater.

[0017] Preferably, the valve arranged at the hot inlet of the regenerative device adopts a backwater regulating valve, the valve arranged at the hot outlet of the regenerative device adopts a water taking shut-off valve, the valve arranged at the cold outlet of the feed water heater adopts a feed water heater outlet shut-off valve, and the valve arranged at the cold inlet of the feed water heater adopts a feed water heater inlet shut-off valve.

[0018] Preferably, the circulating medium in the molten salt hot tank and the hot molten salt pump adopts molten salt, heat conducting oil, liquid metal, gas or water.

[0019] The working method of the generator set shared type peak regulation system has the following processes:

[0020] The energy storage process: the generator in the generator set generates electricity, the cold molten salt pump is started, and the energy storage switch in at least one group of generator sets is closed, the molten salt cold tank is heated by the molten salt electric heater and stored in the molten salt hot tank, and the molten salt cold tank plays a peak regulation role;

[0021] The energy release process: the hot molten salt pump is started, the energy storage switches of all generator sets are opened, the feedwater heater is started, the water in the regenerative device is heated, the heat energy is converted into feedwater heat energy, and the energy in the peak regulation system is released.

[0022] Preferably, when the generator set shared type peak regulation system comprises a heat network water heater, in the energy release process:

[0023] The feedwater heater and the heat network water heater are started, or one of the feedwater heater and the heat network water heater is closed, the heat energy is converted into feedwater heat energy or heat network water heat energy, and the energy in the peak regulation system is released.

[0024] The present application has the following advantages:

[0025] The generator set shared type peak regulation system can realize the sharing of the peak regulation system, can reduce the investment cost, can convert the stored heat energy into the feedwater heat energy of any one generator set for use through the feedwater heater, and can convert the stored heat energy into the heat network water heat energy for use through the heat network water heater. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The figure is a structural schematic diagram of the generator set shared type peak regulation system.

[0027] In the figure, 1-1 is a first steam generator, 1-2 is a first steam power generation device, 1-3 is a first regenerative device, 1-4 is a first generator, 1-5 is a first energy storage switch, 1-6 is a first water intake shut-off valve, 1-7 is a first water return regulating valve, 2-1 is a second steam generator, 2-2 is a second steam power generation device, 2-3 is a second regenerative device, 2-4 is a second generator, 2-5 is a second energy storage switch, 2-6 is a second water intake shut-off valve, 2-7 is a second water return regulating valve, 3-1 is a molten salt cold tank, 3-2 is a cold molten salt pump, 3-3 is a molten salt electric heater, 3-4 is a molten salt hot tank, 3-5 is a hot molten salt pump, 3-6 is a feed water heater inlet shut-off valve, 3-7 is a feed water heater, 3-8 is a feed water heater outlet shut-off valve, 3-9 is a heating network water heater inlet shut-off valve, 3-10 is a heating network water heater, 3-11 is a heating network water heater outlet regulating valve, 3-12 is a heating network water intake shut-off valve, and 3-13 is a heating network water return regulating valve. DETAILED DESCRIPTION

[0028] The application will be further described in detail below in connection with the accompanying drawings and examples:

[0029] Examples

[0030] This example takes setting two groups of generator sets as an example for illustration, such as Figure 1As shown, the generator set shared peak shaving system of the embodiment includes a first generator set, a second generator set and a peak shaving system; wherein the first generator set includes a first steam generator 1-1, a first steam power generation device 1-2 and a first heat recovery device 1-3 which are sequentially connected; further includes a first generator 1-4 connected with the first steam power generation device 1-2 through a main shaft; the second generator set is the same as the first generator set, and the same structure is marked as "2-x", such as the first steam generator 1-1 corresponding to the second steam generator 2-1; the peak shaving system includes a molten salt cold tank 3-1, a cold molten salt pump 3-2, a molten salt electric heater 3-3, a molten salt hot tank 3-4, a hot molten salt pump 3-5, a feed water heater inlet shutoff valve 3-6, a feed water heater 3-7 and a feed water heater outlet shutoff valve 3-8 which are sequentially connected, and the molten salt cold tank 3-1, the cold molten salt pump 3-2, the molten salt electric heater 3-3, the molten salt hot tank 3-4, the hot molten salt pump 3-5, the feed water heater inlet shutoff valve 3-6, the feed water heater 3-7 and the feed water heater outlet shutoff valve 3-8 form a closed circulation; the peak shaving system further includes a hot network water heater inlet shutoff valve 3-9, a hot network water heater 3-10 and a hot network water heater outlet regulating valve 3-11 which are sequentially connected, wherein the interface of the hot network water heater inlet shutoff valve 3-9 is located between the hot molten salt pump 3-5 and the feed water heater inlet shutoff valve 3-6, and the interface of the hot network water heater outlet regulating valve 3-11 is located between the feed water heater outlet shutoff valve 3-8 and the molten salt cold tank 3-1; the hot network water side inlet and outlet of the hot network water heater 3-10 are respectively provided with a hot network water taking shutoff valve 3-12 and a hot network water returning regulating valve 3-13; the first generator 1-4 is connected with the molten salt electric heater 3-3 through a cable, and a first energy storage switch 1-5 is arranged on the cable; the first heat recovery device 1-3 is communicated with the feed water heater 3-7 through a pipeline, and a first water taking shutoff valve 1-6 and a first water returning regulating valve 1-7 are respectively arranged on the water inlet and outlet pipeline; the second generator 2-4 is also connected with the molten salt electric heater 3-3 through a cable, and a second energy storage switch 2-5 is arranged therebetween; the second heat recovery device 2-3 is communicated with the feed water heater 3-7 through a pipeline, and a second water taking shutoff valve 2-6 and a second water returning regulating valve 2-7 are respectively arranged on the water inlet and outlet pipeline; wherein the first generator set and the second generator set in the above system share the peak shaving system, the generator set is two or more than two, and the peak shaving system is one. The peak shaving system can store energy for a single generator set or simultaneously store energy for multiple generator sets. The energy stored by the peak shaving system can heat the feed water of any one or multiple generator sets through the feed water heater 3-7, or heat the hot network water through the hot network water heater 3-10, or simultaneously heat the feed water and the hot network water. The circulating medium of the peak shaving system adopts molten salt, heat conducting oil, liquid metal, gas or water, etc. The peak shaving system uses double-tank energy storage of the molten salt cold tank 3-1 and the molten salt hot tank 3-4, or single-tank energy storage of the thermal gradient layer. The molten salt cold tank 3-1 and the molten salt hot tank 3-4 are provided with these measuring instruments including a liquid level meter, a thermometer and a pressure gauge.The molten salt electric heater 3-3 is of a resistance type, an electromagnetic type or an electrode type.

[0031] As shown in the figure, the working method of the generator unit shared type peak shaving system of the embodiment comprises the following processes: Figure 1

[0032] The energy storage process: start the cold molten salt pump 3-2, close at least one energy storage switch (namely close at least one of the first energy storage switch 1-5 and the second energy storage switch 2-5), according to the energy storage energy use demand, open or close the feed water heater 3-7 and the heat network water heater 3-10, part of the electric energy of the electric generator unit is not put into the grid, is converted into heat energy and is stored in the molten salt heat tank 3-4, and plays a peak shaving role;

[0033] The energy release process: start the hot molten salt pump 3-5, open all energy storage switches, according to the energy storage energy use demand, open or close the feed water heater 3-7 and the heat network water heater 3-10, and the heat energy is converted into feed water heat energy or heat network water heat energy to release the energy in the peak shaving system.

[0034] As can be seen from the above scheme, the generator unit shared type peak shaving system of the application realizes large capacity, long time and high quality energy storage by using electric heating molten salt and other heat storage media, realizes deep peak shaving of the unit, realizes peak shaving of at least two generator units by one peak shaving system, and is a shared type energy storage system; the stored heat energy is converted into feed water heat energy of any one generator unit by the feed water heater for use; the stored heat energy is converted into heat network water heat energy by the heat network water heater for use. In summary, the generator unit shared type peak shaving system of the application can realize energy storage during deep peak shaving of the generator unit and energy release during non-peak shaving, can realize large capacity, long time and deep peak shaving, and the heat energy use is diversified, can realize flexible transformation of the whole plant through single investment, and the equipment utilization rate is high.​

Claims

1. A generator set sharing type peak shaving system, characterized in that, The system comprises a peak regulation system and at least two groups of generator sets, the generator set comprises a steam generator, a steam power generation device, a heat recovery device and a generator, the steam outlet of the steam generator is connected with the steam inlet of the steam power generation device, the steam outlet of the steam power generation device is connected with the cold inlet of the heat recovery device, the cold outlet of the heat recovery device is communicated with the inner cavity of the steam generator, and the steam power generation device is connected with the generator; The peak regulation system comprises a molten salt cold tank (3-1), a cold molten salt pump (3-2), a molten salt electric heater (3-3), a molten salt hot tank (3-4), a hot molten salt pump (3-5) and a feed water heater (3-7) which are sequentially communicated, the inlet of the cold molten salt pump (3-2) is connected with the outlet of the molten salt cold tank (3-1), the outlet of the cold molten salt pump (3-2) is connected with the inlet of the molten salt electric heater (3-3), the outlet of the molten salt electric heater (3-3) is connected with the inlet of the molten salt hot tank (3-4), the inlet of the hot molten salt pump (3-5) is connected with the outlet of the molten salt hot tank (3-4), the outlet of the hot molten salt pump (3-5) is connected with the hot inlet of the feed water heater (3-7), and the hot outlet of the feed water heater (3-7) is connected with the inlet of the molten salt cold tank (3-1). The generators of all the generator sets are electrically connected with the molten salt electric heater (3-3), and an energy storage switch is arranged on the connecting line. The cold outlet of the feed water heater (3-7) is connected with the hot inlets of the heat recovery devices of all the generator sets, and the hot outlets of the heat recovery devices of all the generator sets are connected with the cold inlets of the feed water heater (3-7). Valves are arranged on the hot inlets of the heat recovery devices of all the generator sets, the hot outlets of the heat recovery devices of all the generator sets, the cold outlet of the feed water heater (3-7) and the cold inlet of the feed water heater (3-7). Liquid level meters, thermometers and pressure gauges are arranged on the molten salt cold tank (3-1) and the molten salt hot tank (3-4). The circulating medium in the molten salt hot tank (3-4) and the hot molten salt pump (3-5) is molten salt, heat conducting oil, liquid metal, gas or water.

2. The generator set shared peak shaving system according to claim 1, characterized in that, The system further comprises a heat network water heater (3-10), the hot inlet of the heat network water heater (3-10) is connected with the outlet of the hot molten salt pump (3-5), the hot outlet of the heat network water heater (3-10) is connected with the inlet of the molten salt cold tank (3-1), and the hot inlet and the hot outlet of the heat network water heater (3-10) are respectively provided with a heat network water heater outlet adjusting valve (3-11) and a heat network water heater inlet shut-off valve (3-9).

3. The generator set shared peak shaving system according to claim 2, characterized in that, The cold inlet and the cold outlet of the heat network water heater (3-10) are respectively provided with a heat network backwater adjusting valve (3-13) and a heat network water taking shut-off valve (3-12).

4. The generator set shared peak shaving system according to claim 1, characterized in that, The molten salt cold tank (3-1) and the hot molten salt pump (3-5) adopt double-tank energy storage or use a single-tank energy storage with a temperature gradient.

5. The generator set shared peak shaving system according to claim 1, characterized in that, The molten salt electric heater (3-3) is a resistance type, electromagnetic type or electrode type molten salt electric heater.

6. The generator set shared peak shaving system according to claim 1, characterized in that, The valve arranged on the hot inlet of the heat recovery device is a backwater adjusting valve, the valve arranged on the hot outlet of the heat recovery device is a water taking shut-off valve, the valve arranged on the cold outlet of the feed water heater (3-7) is a feed water heater outlet shut-off valve (3-8), and the valve arranged on the cold inlet of the feed water heater (3-7) is a feed water heater inlet shut-off valve (3-6).

7. The method of operating a shared peaking system for generator sets as set forth in any one of claims 1-6, characterized in that, The process comprises the following steps: Energy storage process: the generator in the generator set generates electricity, the cold molten salt pump (3-2) is started, at least one set of energy storage switches in the generator set is closed, the molten salt cold tank (3-1) is heated by the molten salt electric heater (3-3) and stored in the molten salt hot tank (3-4), and the molten salt hot tank (3-4) plays a peak regulation role; Energy release process: the hot molten salt pump (3-5) is started, the energy storage switches of all generator sets are opened, the feedwater heater (3-7) is started, the water in the regenerative device is heated, the heat energy is converted into feedwater heat energy, and the energy in the peak regulation system is released.

8. The method of working according to claim 7, characterized in that, The shared generator set peak regulation system further comprises a heat network water heater (3-10), and in the energy release process: The feedwater heater (3-7) and the heat network water heater (3-10) are started, or one of the feedwater heater (3-7) and the heat network water heater (3-10) is closed, the heat energy is converted into feedwater heat energy or heat network water heat energy, and the energy in the peak regulation system is released.

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