A device and method for recycling waste heat from high-temperature particles in a garbage incineration power plant

Abstract

The present invention discloses a device and method for recovering and utilizing waste heat from high-temperature particles in a waste incineration power plant, comprising a waste heat boiler, which is connected to the bottom of an incinerator of the waste incineration power plant, and is used to exchange heat with high-temperature particles at the bottom of the incinerator of the waste incineration power plant through a heat exchange medium; a heat exchange medium outlet of the waste heat boiler is connected to an inlet of a first steam turbine, the outlet of the first steam turbine is connected to a first inlet of a first heat exchanger, the first outlet of the first heat exchanger is connected to a first inlet of a third heat exchanger, and the first outlet of the third heat exchanger is connected to the heat exchange medium inlet of the waste heat boiler, forming a steam Rankine cycle; the second outlet of the first heat exchanger is connected to a second inlet of a second heat exchanger, the second outlet of the second heat exchanger is connected to the inlet of a second steam turbine, and the outlet of the second steam turbine is connected to the second inlet of the first heat exchanger, forming an organic Rankine cycle.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste power generation, and in particular to a device and method for recovering waste heat of high-temperature particles in a waste incineration power plant. Background Art

[0002] Landfill used to be the main way to deal with garbage. Its advantages are simple operation and low cost. Its disadvantage is that it occupies a large area. In the long run, the leachate generated during the landfill process is difficult to deal with and will cause pollution of the land and groundwater resources in the area. With the advancement of urbanization, the pressure on landfill is increasing.

[0003] Waste incineration power generation is to release the chemical energy stored in domestic waste through incineration, convert it into heat energy and use it. Compared with landfill, the pollutant gas emissions generated by waste incineration are much lower. At the same time, the electricity and heat generated can also reduce the consumption of non-renewable energy, achieve energy conservation and emission reduction, and is gradually becoming the mainstream of urban domestic waste treatment in my country.

[0004] Although incineration has significant advantages in the harmless treatment of urban domestic waste, there are also some key issues to be resolved. The most widespread problem is that the overall energy efficiency of waste incineration power plants is low, and there is a large loss of low-grade energy, mainly due to the heat loss of boiler combustion and the low-temperature heat loss of tail gas exhaust. In addition, the bottom ash particles at the bottom of the incinerator of the waste incineration power plant also contain a large amount of waste heat energy, but the current waste incineration power plants rarely use this part of heat. The existing technology has not yet utilized the heat in the high-temperature particles at the bottom of the incinerator of the waste incineration power plant, but only utilizes the waste heat in the flue gas, resulting in low energy utilization and waste of resources. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a device and method for recovering waste heat of high-temperature particles in a waste incineration power plant, which improves the output power of the waste incineration power plant.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A waste heat recovery and utilization device for high-temperature particles in a waste incineration power plant, comprising a waste heat boiler, the waste heat boiler being connected to the bottom of an incinerator of the waste incineration power plant, and the waste heat boiler being used to exchange heat with high-temperature particles at the bottom of the incinerator of the waste incineration power plant through a heat exchange medium;

[0008] The heat exchange medium outlet of the waste heat boiler is connected to the inlet of the first steam turbine, the outlet of the first steam turbine is connected to the first inlet of the first heat exchanger, the first outlet of the first heat exchanger is connected to the first inlet of the third heat exchanger, and the first outlet of the third heat exchanger is connected to the heat exchange medium inlet of the waste heat boiler, forming a steam Rankine cycle;

[0009] The second outlet of the first heat exchanger is connected to the second inlet of the second heat exchanger, the second outlet of the second heat exchanger is connected to the inlet of the second steam turbine, and the outlet of the second steam turbine is connected to the second inlet of the first heat exchanger, forming an organic Rankine cycle.

[0010] Preferably, a condenser is provided on the connecting pipe between the outlet of the second steam turbine and the first inlet of the first heat exchanger.

[0011] Preferably, a particle recovery device is provided at the bottom of the waste heat boiler for processing and recovering the high-temperature particles after heat exchange.

[0012] Preferably, a fourth heat exchanger is further included, wherein the second inlet of the third heat exchanger is connected to the return water of the heating network, the second outlet of the third heat exchanger is connected to the second inlet of the fourth heat exchanger, and the second outlet of the fourth heat exchanger is connected to the heating network.

[0013] Furthermore, the first inlet of the second heat exchanger is connected to the flue gas exhaust from the incinerator, and the first outlet of the second heat exchanger is connected to the first inlet of the fourth heat exchanger.

[0014] Furthermore, the second outlet of the fourth heat exchanger is connected to a flue gas treatment device for purifying the flue gas exhaust after heat exchange.

[0015] Preferably, the heat exchange medium is water.

[0016] A method for recycling waste heat from high-temperature particles in a waste incineration power plant, comprising the following steps:

[0017] The high-temperature particles at the bottom of the incinerator of the waste incineration power plant enter the waste heat boiler to exchange heat with the circulating water. The circulating water absorbs the heat of the high-temperature particles to form superheated steam, which is sent to the steam turbine to generate power. The steam after working enters the first heat exchanger to exchange heat with the circulating organic working fluid, and then enters the third heat exchanger to continue to exchange heat with the return water of the heat network and condense into water, and then returns to the waste heat boiler to complete the steam Rankine cycle; the circulating organic working fluid exchanges heat with steam in the first heat exchanger, and then enters the second heat exchanger to exchange heat with the flue gas exhaust discharged from the incinerator to evaporate into steam, and then enters the steam turbine to generate power. The steam of the organic working fluid after working is condensed into liquid through the condenser to complete the organic Rankine cycle.

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

[0019] The present invention provides a waste heat recovery and utilization device for high-temperature particles in a waste incineration power plant. The device recovers the heat in the high-temperature particles at the bottom of the incinerator of the waste incineration power plant through multi-stage heat recovery, forming a steam Rankine cycle and an organic Rankine cycle, realizing the step-by-step recovery of the heat of the high-temperature particles, and improving the output power of the waste incineration power plant. The device recovers the heat of the high-temperature particles by using a waste heat boiler to generate electricity through a steam Rankine cycle, greatly reducing the cooling water consumption in the conventional treatment process of the high-temperature particles. The exhaust steam of the steam turbine in the steam Rankine cycle is exchanged with the return water of the heat network, and the exhaust steam is cooled and condensed into water, so that the condenser is no longer required.

[0020] Furthermore, by recovering low-level heat through heat network return water, the power plant's heat supply and heating income are increased, improving the power plant's economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of a high-temperature particle waste heat recovery and utilization device for a waste incineration power plant according to the present invention;

[0022] In the attached figure: 1 is the waste heat boiler; 2 is the first steam turbine; 3 is the second steam turbine; 4 is the first heat exchanger; 5 is the second heat exchanger; 6 is the third heat exchanger; 7 is the fourth heat exchanger; 8 is the condenser; 9 is the high-temperature particles; 10 is the flue gas exhaust; 11 is the heat network return water; 12 is the circulating water; 13 is the hot steam; 14 is the circulating organic working medium. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0024] A waste heat recovery and utilization device for high-temperature particles in a waste incineration power plant comprises a waste heat boiler 1, which is connected to the bottom of an incinerator of the waste incineration power plant and is used for exchanging heat with high-temperature particles 9 at the bottom of the incinerator of the waste incineration power plant through a heat exchange medium.

[0025] The heat exchange medium outlet of the waste heat boiler 1 is connected to the inlet of the first steam turbine 2. A particle recovery device is provided at the bottom of the waste heat boiler 1 for processing and recovering the high-temperature particles 9 after heat exchange. The outlet of the first steam turbine 2 is connected to the first inlet of the first heat exchanger 4. The first outlet of the first heat exchanger 4 is connected to the first inlet of the third heat exchanger 6. The first outlet of the third heat exchanger 6 is connected to the heat exchange medium inlet of the waste heat boiler 1 to form a steam Rankine cycle. The second inlet of the third heat exchanger 6 is connected to the heat network return water 11. The second outlet of the third heat exchanger 6 is connected to the second inlet of the fourth heat exchanger 7. The second outlet of the fourth heat exchanger 7 is connected to the heat network.

[0026] The second outlet of the first heat exchanger 4 is connected to the second inlet of the second heat exchanger 5, the second outlet of the second heat exchanger 5 is connected to the inlet of the second steam turbine 3, and the outlet of the second steam turbine 3 is connected to the second inlet of the first heat exchanger 4, forming an organic Rankine cycle. The first inlet of the second heat exchanger 5 is connected to the flue gas exhaust 10 discharged from the incinerator, and the first outlet of the second heat exchanger 5 is connected to the first inlet of the fourth heat exchanger 7. A condenser 8 is provided on the connecting pipe between the outlet of the second steam turbine 3 and the first inlet of the first heat exchanger 4. The second outlet of the fourth heat exchanger 7 is connected to the flue gas treatment device, which is used to purify the flue gas exhaust 10 after heat exchange.

[0027] The present invention provides a method for recycling waste heat of high-temperature particles in a waste incineration power plant, which includes the following process: high-temperature particles 9 from the bottom of the incinerator of the waste incineration power plant enter the waste heat boiler 1 to exchange heat with the circulating water 12, and the solid particles after heat exchange are discharged for post-treatment. The circulating water receives the heat of the high-temperature particles to become superheated steam 13, which is sent to the steam turbine 2 to generate power. The steam after working enters the first heat exchanger 4 to exchange heat with the circulating organic working medium 14, and then enters the third heat exchanger 6 to continue to exchange heat with the return water of the heat network and condense into water, and then returns to the waste heat boiler 1 to complete the steam Rankine cycle. The circulating organic working medium 14 exchanges heat with steam in the first heat exchanger 4, enters the second heat exchanger 5 to exchange heat with the flue gas exhaust 10 discharged from the incinerator and evaporates into steam, and then enters the steam turbine 3 to generate power. The organic working medium steam after working passes through the condenser 8 to condense into liquid, completing the organic Rankine cycle. The return water 11 of the heat network passes through the third heat exchanger 6 and the fourth heat exchanger 7 for heat exchange and temperature rise, and then returns to the heat network. The flue gas exhaust 10 discharged from the incinerator is successively sent to post-processing after heat exchange and temperature reduction through the second heat exchanger 5 and the fourth heat exchanger 7.

[0028] The present invention recycles the heat in the high-temperature particles at the bottom of the incinerator of the waste incineration power plant through multi-stage heat recovery, generates electricity through the steam Rankine cycle and the organic Rankine cycle, and improves the output power of the waste incineration power plant. At the same time, the low-level heat of the steam turbine exhaust steam and flue gas in the steam Rankine cycle is fully recovered by using the return water of the heat network, and the return water of the heat network is heated and sent back to the heat network, which can increase the heat supply of the power plant.

[0029] The present invention realizes the step-by-step recovery of heat from high-temperature particles through steam Rankine cycle and organic Rankine cycle, thereby increasing the output power of the waste incineration power plant.

[0030] The present invention uses a waste heat boiler to recover the heat of high-temperature particles to perform steam Rankine cycle power generation, thereby greatly reducing the cooling water consumption in the conventional treatment process of high-temperature particles.

[0031] The present invention recovers low-level heat through heat network return water, increases the heat supply and heat supply income of the power plant, and improves the economic benefits of the power plant.

[0032] The present invention exchanges heat between exhaust steam from a steam turbine and return water from a heat network in a steam Rankine cycle, cools the exhaust steam and condenses it into water, and no condenser is required.

Claims

1. A waste incineration power plant high temperature particle waste heat recovery and utilization device, characterized in that: The waste heat boiler (1) is connected to the bottom of an incinerator of a waste incineration power plant, and the waste heat boiler (1) is used to exchange heat with high-temperature particles (9) at the bottom of the incinerator of the waste incineration power plant through a heat exchange medium; The heat exchange medium outlet of the waste heat boiler (1) is connected to the inlet of the first steam turbine (2), the outlet of the first steam turbine (2) is connected to the first inlet of the first heat exchanger (4), the first outlet of the first heat exchanger (4) is connected to the first inlet of the third heat exchanger (6), and the first outlet of the third heat exchanger (6) is connected to the heat exchange medium inlet of the waste heat boiler (1), forming a steam Rankine cycle; The second outlet of the first heat exchanger (4) is connected to the second inlet of the second heat exchanger (5), the second outlet of the second heat exchanger (5) is connected to the inlet of the second steam turbine (3), and the outlet of the second steam turbine (3) is connected to the second inlet of the first heat exchanger (4), thereby forming an organic Rankine cycle; It also comprises a fourth heat exchanger (7), wherein the second inlet of the third heat exchanger (6) is connected to the heat network return water (11), the second outlet of the third heat exchanger (6) is connected to the second inlet of the fourth heat exchanger (7), and the second outlet of the fourth heat exchanger (7) is connected to the heat network; The first inlet of the second heat exchanger (5) is connected to the flue gas exhaust (10) discharged from the incinerator, and the first outlet of the second heat exchanger (5) is connected to the first inlet of the fourth heat exchanger (7); The second outlet of the fourth heat exchanger (7) is connected to a flue gas treatment device for purifying the flue gas tail gas (10) after heat exchange; A condenser (8) is provided on the connecting pipe between the outlet of the second steam turbine (3) and the first inlet of the first heat exchanger (4).

2. The high-temperature particle waste heat recovery and utilization device of a waste incineration power plant according to claim 1 is characterized in that: A particle recovery device is provided at the bottom of the waste heat boiler (1) for processing and recovering the high-temperature particles (9) after heat exchange.

3. The high-temperature particle waste heat recovery and utilization device of a waste incineration power plant according to claim 1 is characterized in that: The heat exchange medium is water.

4. A method for recycling waste heat from high-temperature particles in a waste incineration power plant, characterized in that: Including the following process, High-temperature particles (9) at the bottom of the incinerator of the waste incineration power plant enter the waste heat boiler (1) to exchange heat with the circulating water (12); the circulating water (12) receives the heat from the high-temperature particles (9) to form superheated steam (13), which is sent to the first steam turbine (2) to generate power; the steam after the power generation enters the first heat exchanger (4) to exchange heat with the circulating organic working medium (14), then enters the third heat exchanger (6) to continue to exchange heat with the return water of the heat network and condense into water, and then returns to the waste heat boiler (1), completing the steam Rankine cycle; the circulating organic working medium (14) exchanges heat with the steam in the first heat exchanger (4), then enters the second heat exchanger (5) to exchange heat with the flue gas (10) discharged from the incinerator and evaporates into steam, then enters the second steam turbine (3) to generate power; the steam of the organic working medium after the power generation passes through the condenser (8) to condense into liquid, completing the organic Rankine cycle; The return water (11) from the heat network is heated by the third heat exchanger (6) and the fourth heat exchanger (7) and then returns to the heat network; the flue gas (10) discharged from the incinerator is cooled by the second heat exchanger (5) and the fourth heat exchanger (7) and then sent to post-processing.

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