Multi-stage steam device utilizing waste heat recovery

Abstract

A multi-stage steam device utilizing waste heat recovery comprises a heat source, a heat exchange system and a steam preparation system. The heat exchange system comprises a waste heat exchanger and a water supplementing heat exchanger which are both communicated with a heat source, and the waste heat exchanger is communicated with the water supplementing heat exchanger through a pipeline; the steam preparation system comprises a flash tank and a steam compressor which are communicated with each other, the flash tank is connected with the waste heat exchanger in a heat exchange manner, and the flash tank is communicated with the water supplementing heat exchanger through a pipeline; the water replenishing heat exchanger is provided with a water replenishing tank which is communicated through a pipeline; compared with the prior art, by arranging the waste heat exchanger and the water supplementing heat exchanger which are communicated with each other, multi-stage heat exchange of a heat source is achieved, effective utilization of the heat source is achieved, meanwhile, the waste heat exchanger and the water supplementing heat exchanger are arranged corresponding to the circulation position of the flash tank and the water inlet position of the flash tank respectively, and multi-stage heat exchange of water flow in the flash tank is achieved; and the temperature of water flow in the flash tank is increased, so that the energy consumption required by the flash tank is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of multistage steam device of waste heat recovery, and specifically relates to a kind of multistage steam device of waste heat recovery. BACKGROUND

[0002] Waste heat refers to sensible heat and latent heat that is not reasonably utilized in the original design in the energy-consuming device of the industrial enterprise that has been put into operation. Waste heat includes high-temperature exhaust gas waste heat, cooling medium waste heat, waste steam and waste water waste heat, high-temperature product and slag waste heat, chemical reaction waste heat, combustible waste gas, waste liquid and waste material waste heat, etc.

[0003] Waste heat recovery is an important way to improve economic efficiency and save fuel. The utilization of waste heat mainly has two functions: one is to produce low-quality steam for production and living needs, and the other is to produce high-pressure steam for power generation. High-pressure steam can be converted into electricity for production, thereby alleviating the tense situation of enterprise electricity and reducing the primary energy consumption of enterprises, with double economic benefits of energy saving and cost reduction.

[0004] Gas-fired steam boiler is a traditional steam generation equipment. Gas is introduced into the combustion chamber and mixed with air to burn, producing high-temperature flue gas. The heat energy is transferred to the water through the pipes and smoke pipes in the boiler. The water is heated in the boiler pipes and smoke pipes, and the temperature gradually rises and is converted into steam. When the water reaches the evaporation temperature, it will form steam and be discharged from the boiler.

[0005] Gas-fired steam boiler uses gas as energy, and gas belongs to non-renewable energy. With the increasing shortage of gas resources and the rising price, gas cost has become an important part of the production and operation cost of enterprises. In addition, the instability of gas supply has a great impact on the production of enterprises.

[0006] Although gas-fired boiler uses clean energy such as natural gas, there is still a certain amount of emission, which does not meet the environmental protection requirement of zero emission.

[0007] Boiler belongs to special equipment, and the gas burned belongs to flammable and explosive product, so safety inspection needs to be carried out regularly to ensure production safety. This increases the safety management cost and operation cost of enterprises.

[0008] Traditional boiler needs a long time from opening to stable steam output, and the steam output efficiency is low, which leads to long preheating time and long production cycle, thereby reducing the production efficiency of enterprises

[0009] In the production process of enterprises, a large amount of low-temperature waste heat is discharged to the nature, which not only wastes energy but also pollutes the environment. Recycling waste heat not only reduces the consumption of fossil fuels but also reduces the production cost of enterprises.

[0010] CN201820093893.2 discloses a kind of recovery waste heat compressed steam driven absorption heat pump device, including waste heat recovery system, steam compression system, absorption heat pump system three parts, recycling of industrial waste heat, with waste heat for low pressure flash evaporation of working fluid water, steam compressor re-compression steam driven absorption heat pump device, realize the double effect of waste heat recovery, building air conditioning.

[0011] The waste heat recovery device disclosed in the above needs to supplement water in steam generation, and the heat released by the superheated steam is used for heat exchange operation of the supplemented water, which affects the overall steam heating effect. Practical new type content

[0012] The utility model discloses to overcome the defect in the prior art, provide a kind of energy conversion rate, even in lower heat source temperature condition still can stable steam preparation of the utilization waste heat recovery multistage steam device.

[0013] To realize the above-mentioned utility model purposes, the utility model adopts the following technical solutions: a kind of utilization waste heat recovery multistage steam device, including heat source, heat exchange system and steam preparation system;The heat exchange system includes waste heat exchanger and make-up water heat exchanger, and waste heat exchanger and make-up water heat exchanger are connected by pipeline;The steam preparation system includes flash tank and steam compressor, and flash tank is connected with waste heat exchanger, and flash tank and make-up water heat exchanger are connected by pipeline;The make-up water heat exchanger is equipped with make-up water tank connected by pipeline, and make-up water heat exchanger and steam compressor are connected by pipeline.

[0014] As a preferred scheme of the utility model, the heat source is provided with waste heat pipeline sequentially flowing through waste heat exchanger and make-up water heat exchanger, and the heat source is further provided with shunt pipeline communicated with the middle part of waste heat pipeline, and the shunt pipeline is located between waste heat exchanger and make-up water heat exchanger.

[0015] As a preferred scheme of the utility model, the make-up water tank is provided with make-up water pipeline communicated with flash tank, and the make-up water pipeline flows through make-up water heat exchanger.

[0016] As a preferred scheme of the utility model, the make-up water pipeline is provided with branch pipeline communicated with steam compressor, and the branch pipeline is communicated between make-up water heat exchanger and flash tank.

[0017] As a preferred scheme of the utility model, the make-up water pipeline is provided with make-up water pump and first solenoid valve for controlling the make-up water amount of flash tank, and the branch pipeline is provided with pressurizing pump and second solenoid valve for controlling the make-up water amount of steam compressor.

[0018] As a preferred scheme of the utility model, the flash tank is equipped with a circulating pipeline for heat exchange through the waste heat exchanger, and the circulating pipeline is equipped with a circulating pump for controlling the water flow in the flash tank to exchange heat.

[0019] As a preferred scheme of the utility model, the flash tank is further connected with a vacuum pump for controlling the internal pressure of the flash tank.

[0020] As a preferred scheme of the utility model, the top of the flash tank is equipped with a gas outlet pipeline in communication with the steam compressor.

[0021] As a preferred scheme of the utility model, the bottom of the flash tank is equipped with a blowdown valve.

[0022] As a preferred scheme of the utility model, the water supplement pipeline is equipped with a first stop valve for controlling the input of the flash tank and a second stop valve for controlling the input of the steam compressor.

[0023] Compared with the prior art, the utility model has the beneficial effects that: by setting the waste heat exchanger and the water supplement heat exchanger in communication, multi-stage heat exchange of the heat source is realized, effective utilization of the heat source is realized, the waste heat exchanger and the water supplement heat exchanger are arranged at the circulating position of the flash tank and the water inlet position of the flash tank respectively, multi-stage heat exchange of the water flow in the flash tank is realized, the temperature of the water flow in the flash tank is improved, and thus the required energy consumption of the flash tank is reduced;

[0024] In the use process, no other energy source is consumed except electric energy, steam production is stable, and the cost is far lower than the steam production cost of a gas boiler;

[0025] Zero emission in the running process, in line with environmental protection requirements, high gas outlet efficiency, ready to use, conducive to improving production efficiency, low temperature requirement for the waste heat source, the flash tank only needs to produce low-pressure low-stage steam, and high-pressure high-stage steam can be finally obtained through the multi-stage mechanical compressor. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 It is the plane layout drawing of the utility model;

[0027] Fig. 2 It is the structural schematic view of the utility model;

[0028] Fig. 3 It is the front view of the utility model;

[0029] Figure numerals: waste heat exchanger 1-1, make-up water heat exchanger 1-2, drain valve 2-1, first stop valve 2-2, second stop valve 2-3, make-up water pump 3-1, booster pump 3-2, circulation pump 3-3, first solenoid valve 4-1, second solenoid valve 4-2, make-up water tank 5, steam compressor 6, flash tank 7, vacuum pump 8, waste heat pipeline 9, diversion pipeline 9-1, circulation pipeline 10, make-up water pipeline 11, branch pipeline 11-1, outlet pipeline 12. DETAILED DESCRIPTION

[0030] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings.

[0031] like Figs. 1-3 As shown, a multi-stage steam device utilizing waste heat recovery includes a heat source, a heat exchange system, and a steam preparation system; the heat exchange system includes a waste heat heat exchanger 1-1 and a make-up water heat exchanger 1-2, both of which are connected to the heat source, and the waste heat exchanger 1-1 and the make-up water heat exchanger 1-2 are connected through a pipeline; the steam preparation system includes a flash tank 7 and a steam compressor 6 that are connected, the flash tank 7 is heat-exchange connected to the waste heat exchanger 1-1, and the flash tank 7 is connected to the make-up water heat exchanger 1-2 through a pipeline; the make-up water heat exchanger 1-2 is provided with a make-up water tank 5 connected through a pipeline, and the make-up water heat exchanger 1-2 is connected to the steam compressor 6 through a pipeline.

[0032] The heat source can be waste hot water with a certain amount of heat. The waste hot water flows through the waste heat exchanger 1-1 and the make-up water heat exchanger 1-2 in sequence. When the waste hot water flows through the waste heat exchanger 1-1, it realizes heat exchange with the water in the flash tank 7, and when the waste hot water flows through the make-up water heat exchanger 1-2, it realizes heat exchange with the water flowing out of the make-up water tank 5.

[0033] The flash tank 7 is used to receive the water after heat exchange and generate low-order steam, while the steam compressor 6 is used to receive low-order steam and the water after heat exchange and generate high-order steam. The generated high-pressure steam can be used to provide better temperature and pressure, and is suitable for high-energy consumption industrial production processes.

[0034] The heat source is provided with a waste heat pipeline 9 which flows through the waste heat exchanger 1-1 and the make-up water heat exchanger 1-2 in sequence, and the heat source is also provided with a diversion pipeline 9-1 which is connected to the middle part of the waste heat pipeline 9. The diversion pipeline 9-1 is located between the waste heat exchanger 1-1 and the make-up water heat exchanger 1-2.

[0035] The waste heat water serves as a heat source to provide heat for the waste heat exchanger 1-1 and the make-up water heat exchanger 1-2. Under the action of the waste heat exchanger 1-1 and the make-up water heat exchanger 1-2, the heat of the waste heat pipeline 9 is exchanged with the make-up water pipeline 11 and the circulation pipeline 10. The waste heat pipeline 9 first passes through the waste heat exchanger 1-1 and then passes through the make-up water heat exchanger 1-2, thereby realizing the primary heat exchange in the waste heat exchanger 1-1 and the secondary heat exchange in the make-up water heat exchanger 1-2.

[0036] The primary heat exchange effect of the residual heat pipeline 9 is better than the secondary heat exchange effect of the residual heat pipeline 9, so that the heat exchange effect of the circulating pipeline 10 is better than the heat exchange effect of the make-up water pipeline 11, and the make-up water pipeline 11 and the circulating pipeline 10 are connected under the action of the flash tank 7, so that the water in the make-up water pipeline 11 can be heated by the make-up water heat exchanger 1-2 and then heated by the residual heat heat exchanger 1-1, thereby realizing the step-by-step heat exchange of the single water flow from low to high and improving the heat exchange effect.

[0037] The residual heat pipeline 9 is provided with a three-way joint for connecting a shunt pipeline 9-1, and the shunt pipeline 9-1 is also used for directly connecting a heat source. Under the action of the shunt pipeline 9-1, the temperature of the residual heat pipeline 9 flowing through the make-up water heat exchanger 1-2 is increased, and the residual heat water in the shunt pipeline 9-1 is used for mixing with the residual heat water flowing through the residual heat heat exchanger 1-1.

[0038] Since the temperature of the residual heat water flowing through the residual heat heat exchanger 1-1 is reduced under the action of the residual heat, the temperature of the water flow in the residual heat pipeline 9 is increased by the residual heat water in the shunt pipeline 9-1, thereby ensuring that the make-up water heat exchanger 1-2 also has a good heat exchange effect in the heat exchange process. At the same time, since the water flow flowing through the make-up water heat exchanger 1-2 is mixed with the residual heat water after the primary heat exchange and the residual heat water after the secondary heat exchange, the temperature of the mixed residual heat water is necessarily lower than that of the residual heat water after the primary heat exchange, thereby satisfying the above-mentioned condition that the primary heat exchange effect in the residual heat heat exchanger 1-1 is better than the secondary heat exchange effect in the make-up water heat exchanger 1-2.

[0039] The make-up water tank 5 is provided with a make-up water pipeline 11 connected with the flash tank 7, and the make-up water pipeline 11 flows through the make-up water heat exchanger 1-2. Under the action of the make-up water pipeline 11, the water in the flash tank 7 is supplemented to meet the demand of the flash tank for continuously generating low-stage steam. At the same time, under the action of the make-up water heat exchanger 1-2, the water flowing out of the make-up water tank 5 is heated, thereby increasing the temperature of the water flow into the flash tank 7 and reducing the energy consumption required for the flash tank 7 to generate low-stage steam.

[0040] The make-up water pipeline 11 is provided with a branch pipeline 11-1 connected with the steam compressor 6, and the branch pipeline 11-1 is connected between the make-up water heat exchanger 1-2 and the flash tank 7. The make-up water pipeline 11 can simultaneously realize the water supplement operation for the flash tank 7 and the steam compressor 6, and the water flow for supplementing the steam compressor 6 also flows through the make-up water heat exchanger 1-2 for heat exchange.

[0041] The flash tank 7 is also connected with a vacuum pump 8 for controlling the internal pressure of the flash tank 7.

[0042] In use, the flash tank 7 is pressure drawn low by the vacuum pump 8, when the system is running, the circulating water in the circulating pipeline 10 passes through the waste heat exchanger 1-1 to absorb heat from the waste heat water to increase the temperature, and then returns to the flash tank 7 to flash out low-temperature and low-pressure saturated steam, the make-up water of the flash tank 7 passes through the make-up water heat exchanger 1-2 in the make-up water pipeline 11 to further absorb heat from the waste heat water, part of which enters the flash tank 7 through the make-up water pipeline 11, and the other part enters the cooling water system of the steam compressor 6 through the branch pipeline 11-1 to protect the unit from overheating, and at the same time, the heat generated by the steam compressor 6 during work can evaporate the make-up water to increase the steam production. The steam compressor 6 is driven by electric energy to provide steam for the production system continuously.

[0043] The make-up water pipeline 11 is provided with a make-up water pump 3-1 and a first electromagnetic valve 4-1 for controlling the make-up water amount of the flash tank 7, and the branch pipeline 11-1 is provided with a pressurizing pump 3-2 and a second electromagnetic valve 4-2 for controlling the make-up water amount of the steam compressor 6.

[0044] The first electromagnetic valve 4-1 and the make-up water pump 3-1 are used to control the make-up water amount of the flash tank 7 by the make-up water tank 5, and under the action of the first electromagnetic valve 4-1 and the make-up water pump 3-1, the flash tank 7 can supplement the water amount with the same mass as the steam during the drainage of the flash tank 7, so as to ensure that the flash tank 7 is always in a relatively constant pressure environment.

[0045] The pressurizing pump 3-2 and the second electromagnetic valve 4-2 are used to control the make-up water amount of the steam compressor 6, and under the action of the pressurizing pump 3-2 and the second electromagnetic valve 4-2, the outlet steam superheat degree of the steam compressor 6 can be adjusted to ensure that the steam compressor 6 can output superheated / saturated steam.

[0046] The flash tank 7 is provided with a circulating pipeline 10 for heat exchange through the waste heat exchanger 1-1, and the circulating pipeline 10 is provided with a circulating pump 3-3 for controlling the water flow in the flash tank 7 to perform heat exchange.

[0047] The circulating pump 3-3 is used to drive the flow of the water flow in the circulating pipeline 10, and under the action of the flow of the water flow in the circulating pipeline 10, the circulating pipeline 10 and the waste heat exchanger 1-1 cooperate to realize the heat exchange and heating effect of the water flow in the flash tank 7.

[0048] The top of the flash tank 7 is provided with a gas outlet pipeline 12 connected with the steam compressor 6, under the action of the flash tank 7, low-stage steam is formed in the flash tank 7, and under the action of the low-stage steam itself, the low-stage steam is discharged upward, and then flows into the steam compressor 6 through the gas outlet pipeline 12, and the bottom of the flash tank 7 is provided with a blowdown valve 2-1.

[0049] The make-up water pipeline 11 is provided with a first stop valve 2-2 for controlling the input amount of the flash tank 7 and a second stop valve 2-3 for controlling the input amount of the steam compressor 6.

[0050] In actual use, the waste heat pipeline 9 flows through the waste heat exchanger 1-1 and the make-up water exchanger 1-2 in sequence, so that the waste heat pipeline 9 realizes multi-stage heat exchange on the waste heat exchanger 1-1 and the make-up water exchanger 1-2, and realizes heat exchange on the water in the flash tank 7 in the waste heat exchanger 1-1, and the make-up water exchanger 1-2 is used for heat exchange on the water supply of the make-up water tank 5, so as to realize multi-stage heat exchange on the water inlet of the flash tank 7 and the internal circulation of the flash tank 7, and ensure effective utilization of waste heat water.

[0051] The above description of disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application; therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

[0052] Although the terms: waste heat exchanger 1-1, make-up water exchanger 1-2, blowdown valve 2-1, first stop valve 2-2, second stop valve 2-3, make-up water pump 3-1, pressurizing pump 3-2, circulating pump 3-3, first electromagnetic valve 4-1, second electromagnetic valve 4-2, make-up water tank 5, steam compressor 6, flash tank 7, vacuum pump 8, waste heat pipeline 9, shunt pipeline 9-1, circulating pipeline 10, make-up water pipeline 11, branch pipeline 11-1, gas outlet pipeline 12, etc. are used more frequently in the drawings, but the possibility of using other terms is not excluded. The use of these terms is only for the convenience of describing and explaining the essence of the present application; any interpretation of them as additional limitations is contrary to the spirit of the present application.

Claims

1. A multi-stage steam device utilizing waste heat recovery, comprising a heat source, a heat exchange system and a steam preparation system; characterized in that: The heat exchange system comprises a waste heat heat exchanger (1-1) and a water supply heat exchanger (1-2), both of which are connected to a heat source, and the waste heat heat exchanger (1-1) and the water supply heat exchanger (1-2) are connected via a pipeline; the steam preparation system comprises a flash tank (7) and a steam compressor (6) which are connected to each other, the flash tank (7) and the waste heat exchanger (1-1) being heat-exchange connected, and the flash tank (7) and the water supply heat exchanger (1-2) being connected via a pipeline; the water supply heat exchanger (1-2) is provided with a water supply tank (5) connected via a pipeline, and the water supply heat exchanger (1-2) and the steam compressor (6) are connected via a pipeline.

2. The multi-stage steam device utilizing waste heat recovery according to claim 1, characterized in that: The heat source is provided with a waste heat pipeline (9) that flows through the waste heat exchanger (1-1) and the water supply heat exchanger (1-2) in sequence, and the heat source is also provided with a shunt pipeline (9-1) that is connected to the middle part of the waste heat pipeline (9), and the shunt pipeline (9-1) is located between the waste heat exchanger (1-1) and the water supply heat exchanger (1-2).

3. The multi-stage steam device utilizing waste heat recovery according to claim 1, characterized in that: The water supply tank (5) is provided with a water supply pipeline (11) connected to the flash tank (7), and the water supply pipeline (11) flows through the water supply heat exchanger (1-2).

4. The multi-stage steam device utilizing waste heat recovery according to claim 3, characterized in that: The water supply pipeline (11) is provided with a branch pipeline (11-1) connected to the steam compressor (6), and the branch pipeline (11-1) is connected between the water supply heat exchanger (1-2) and the flash tank (7).

5. The multi-stage steam device utilizing waste heat recovery according to claim 4, characterized in that: The water supply pipeline (11) is provided with a water supply pump (3-1) and a first solenoid valve (4-1) for controlling the water supply amount of the flash tank (7), and the branch pipeline (11-1) is provided with a booster pump (3-2) and a second solenoid valve (4-2) for controlling the water supply amount of the steam compressor (6).

6. The multi-stage steam device utilizing waste heat recovery according to claim 1, characterized in that: The flash tank (7) is provided with a circulation pipeline (10) for performing heat exchange through a waste heat exchanger (1-1), and the circulation pipeline (10) is provided with a circulation pump (3-3) for controlling the water flow in the flash tank (7) for performing heat exchange.

7. The multi-stage steam device utilizing waste heat recovery according to claim 6, characterized in that: The flash tank (7) is also connected to a vacuum pump (8) for controlling the internal pressure of the flash tank (7).

8. The multi-stage steam device utilizing waste heat recovery according to claim 6, characterized in that: The top of the flash tank (7) is provided with an air outlet pipeline (12) connected to the steam compressor (6).

9. The multi-stage steam device utilizing waste heat recovery according to claim 6, characterized in that: A sewage valve (2-1) is provided at the bottom of the flash tank (7).

10. The multi-stage steam device utilizing waste heat recovery according to claim 3, characterized in that: The water supply pipeline (11) is provided with a first stop valve (2-2) for controlling the input amount of the flash tank (7) and a second stop valve (2-3) for controlling the input amount of the steam compressor (6).

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