Novel thermal power plant concrete rapid heat storage and heat exchange system

Abstract

The utility model discloses a novel thermal power plant concrete rapid heat storage and exchange system which comprises a thermal power plant heat supply system, a concrete heat exchange and storage system and a heat supply network heater. The device is used for rapid storage and effective utilization of thermal power plant electric energy and heating steam heat energy, thermal decoupling of a thermal power plant is achieved, unit operation flexibility is improved, and the development requirement of the electric power spot market is better met.

Description

TECHNICAL FIELD

[0001] The utility model relates to a novel thermal power plant concrete rapid heat storage and exchange system, belong to the field for thermal power plant electric energy, heating steam heat energy's storage and effective utilization, it realizes thermal power plant heat electricity decoupling, improves unit operation flexibility, better adapts to the development needs of electric power spot market. BACKGROUND

[0002] In order to reduce fossil energy consumption and reduce carbon emissions, the state vigorously develops non-water renewable energy installed capacity. After large-scale new energy grid connection enters the electric power spot market, it brings many problems, wind energy, solar energy resources are not controllable, new energy power generation output has great randomness, volatility and intermittency, after the actual operation situation investigation of thermal power unit in the continuous operation area of electric power spot market, the spot market puts forward higher requirements to the regulation range, climbing rate and start-stop performance of thermal power unit. From the angle of offer, in order to improve the competitiveness of thermal power unit in the spot market, obtain more opportunities of auxiliary service such as peak shaving and standby, the probability of starting the unit first and stopping the unit later is greater, and the income obtained will be more.

[0003] Thermal power plants undertake the task of heating residents in winter, it is impossible to start and stop the unit at any time just to meet the profit of spot market, therefore a novel thermal power plant concrete heat exchange and storage system is proposed, the characteristics of high heat storage capacity and high heat exchange efficiency of concrete heat storage unit are used, the short time storage of low price electricity energy in valley section and heating steam heat energy, through the temporary acceptance of heating task of concrete heat exchange and storage system, thermal power unit can generate high price electricity energy in peak section, better participate in spot market and auxiliary service. Compared with the common molten salt heat storage technology, concrete heat storage material is convenient to obtain and low in cost, suitable for modular design, manufacturing and installation. SUMMARY

[0004] The utility model aims at overcoming the insufficient of prior art, and provides a novel thermal power plant concrete rapid heat storage and exchange system with simple structure and convenient use.

[0005] In order to realize the above-mentioned invention purpose, the utility model adopts the following technical scheme.

[0006] A novel rapid concrete heat storage and exchange system for thermal power plants mainly consists of a thermal power plant heating system, a concrete heat exchange and storage system, and a heating network heater. Its key feature is that the thermal power plant heating system sequentially connects the generator, turbine, boiler, condenser, and deaerator via steam and water pipelines, achieving external heating through heat exchange between the heating steam in the pipelines and the heating network heater. The concrete heat exchange and storage system comprises a concrete heat storage unit, a small steam drum, and a condensate tank. It utilizes excess heating steam or low-cost off-peak electricity to heat the concrete heat storage unit briefly, either individually or simultaneously, and then provides heating steam after heat exchange. Steam condenses into water which flows into the condensate tank. The water is then pumped to the deaerator and returned to the power plant's water circulation system via a circulating pump. When the power grid is at its peak load, the unit can temporarily decouple from the thermoelectric system to meet peak loads or provide auxiliary services. The concrete thermal storage unit briefly takes over the heating task. The heated concrete thermal storage unit releases heat to the heat exchange pipes and, in conjunction with the condensate tank and small steam drum, continuously delivers the heat-exchanged steam to the heating pipes for heat exchange with the heating network heaters, providing continuous heating services. After heat exchange, the condensate returns to the condensate tank and is pumped to the deaerator for recirculation via a circulating pump.

[0007] The aforementioned novel rapid thermal storage and heat exchange system for concrete in thermal power plants is characterized in that: the concrete thermal storage unit consists of a concrete block, an inlet pipe, an inlet control valve, an inlet thermometer, a pressure gauge, an electric heating unit, a heat exchange pipe, an outlet pipe, an outlet thermometer, an outlet control valve, and an insulation layer. The concrete block is a cube with a side length of 1m, which facilitates transportation and assembly. The size of the concrete thermal storage unit can be determined according to the actual thermal storage needs of the thermal power plant. To improve heat exchange efficiency and adapt to the rapidly changing electricity spot market, the concrete is heated rapidly. Each concrete block has an electric heating unit evenly distributed around its perimeter. The heating temperature of the electric heating unit can be flexibly set according to the electricity price and actual needs. The concrete block contains nine heat exchange pipes of equal diameter distributed according to a certain pattern. The two ends of the heat exchange pipes are connected to the inlet and outlet pipes. The steam temperature and pressure are detected by thermometers and pressure gauges, and the steam flow is controlled by the control valves. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the rapid heat storage and heat exchange system of this utility model.

[0009] Figure 2 This is a schematic diagram of the concrete heat storage unit of this utility model.

[0010] Figure 3 This is a schematic diagram of the concrete heat storage unit of this utility model.

[0011] In the diagram: 1.1 Generator 1.2 Steam turbine 1.3 Boiler 1.4 Condenser 1.5 Deaerator.

[0012] In the diagram: 2.1 Concrete block. 2 Inlet pipe. 3 Inlet control valve. 4 Inlet thermometer and pressure gauge. 5 Electric heating unit. 6 Heat exchange pipe. 7 Outlet pipe. 8 Outlet thermometer and pressure gauge. 9 Outlet control valve. 10 Insulation layer. Detailed Implementation

[0013] To better understand the technical solution of this invention patent, the embodiments provided by this invention patent are described in detail below with reference to the accompanying drawings.

[0014] This invention provides a novel rapid concrete heat storage and exchange system for thermal power plants. The boiler in the thermal power plant burns fuel to heat water, generating steam at a certain temperature and pressure. This steam performs work, driving a turbine to rotate and a generator to produce electricity. Simultaneously, the steam that has performed work in the turbine's intermediate-pressure cylinder is extracted in five stages. The extracted steam is transported through heating pipelines to exchange heat with the heating network heaters for external heating. To enhance the competitiveness of thermal power units in the spot market and gain more opportunities to participate in ancillary services such as peak shaving and standby, and to improve the efficiency of heat recovery and utilization, the heating steam in the heat exchange pipelines is extracted. The excess heating steam or low-cost electricity during off-peak hours is used in the concrete heat exchange and storage system to heat the concrete storage unit for a short time, either individually or simultaneously. After heat exchange, the heating steam condenses into water and flows into a condensate tank. A circulating pump then sends the water to the deaerator, returning it to the thermal power plant's water circulation system.

[0015] When the power grid is under peak load, the generating unit can temporarily decouple from the thermoelectric system to meet peak load or provide auxiliary services. The concrete thermal storage unit briefly takes over the heating task. After heating, the concrete thermal storage unit releases heat to the heat exchange pipes, and in conjunction with the condensate tank and small steam drum, continuously delivers the heat-exchanged steam to the heating pipes for heat exchange with the heating network heaters. After heat exchange, the condensate returns to the condensate tank and is then sent to the deaerator for recirculation via a circulating pump. Simulation results show that after 2 hours of heating with steam and electric heating units, the average temperature of the concrete blocks can reach over 400℃, meeting the heating requirements. The concrete temperature can also be further increased to meet different heating needs based on actual requirements.

Claims

1. A novel rapid thermal storage and heat exchange system for concrete in thermal power plants, comprising a thermal power plant heating system, a concrete heat exchange and storage system, and a heat network heater, characterized in that: The heating system of the thermal power plant connects the generator, turbine, boiler, condenser, and deaerator sequentially via steam and water pipelines. Heating is provided externally through heat exchange between the heating steam in the pipelines and the heating network heaters. The concrete heat exchange and storage system consists of concrete storage units, a small steam drum, and a condensate tank. It utilizes surplus heating steam or low-cost electricity during off-peak hours to heat the concrete storage units briefly, either individually or simultaneously. Each concrete storage unit is composed of multiple concrete blocks, each containing nine heat exchange pipes of equal diameter distributed according to a specific pattern. Electric heating units are evenly distributed around each concrete block. After heat exchange, the heating steam condenses into water and flows into the condensate tank. A circulating pump then sends the water to the deaerator, returning it to the thermal power plant's water circulation system. The heated concrete storage unit releases heat to the heat exchange pipes, continuously supplying the steam after heat exchange to the heating pipelines in conjunction with the condensate tank and the small steam drum. The condensate then returns to the condensate tank and is sent to the deaerator for recirculation via a circulating pump.

2. The novel rapid thermal storage and heat exchange system for concrete in thermal power plants according to claim 1, characterized in that: The concrete block is a cube with a side length of 1m; the electric heating unit can be set to a heating temperature; the heat exchange pipe is connected to the inlet and outlet pipes at both ends; the inlet and outlet pipes are equipped with control valves, thermometers and pressure gauges.

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