CN206001925U - A kind of rotary kiln flue gas heat recovery device - Google Patents

Abstract

The utility model discloses a rotary kiln flue gas waste heat recovery and utilization device, which comprises a heat collecting device, a heat supply device and a water supply device; The flue gas inlet and flue gas outlet are connected to the existing flue gas pipeline, and the heat collector is connected to the heat exchanger to send the high-temperature flue gas to the heating device; the heating device includes a heat exchanger, a heating circulation pump, a heating constant pressure The water supply pump; the heat exchanger is connected with the heat collector to form a circulation loop, and the heat source of the heat exchanger forms a circulation loop with the heating user; the water supply device includes a water softener and a water softener water supply pump; the water softener is a heat exchanger, a heat collector water supply. The device uses a heat collector to recover the waste heat of the flue gas and uses ORC technology to generate electricity; in the heating season, the plate heat exchanger is used to supply heat to the building, making full use of the waste heat of the waste gas of the rotary kiln.

Description

A rotary kiln flue gas waste heat recovery and utilization device

technical field

The utility model relates to a rotary kiln flue gas waste heat recovery and utilization device, which belongs to the field of machinery and energy saving.

Background technique

At present, the temperature of flue gas discharged from the rotary kiln preheater is generally about 180~240°C. Due to the lack of effective technical means, this part of the scattered but huge amount of energy has not been fully utilized. However, the medium working parameters of traditional power generation technology are mostly high parameters and large capacity.

High flue gas temperature will easily make the surface temperature of the equipment and pipes too high, which may cause burns to the staff; in addition, the rise of the temperature of the equipment will cause the deformation of the equipment, shorten the service life of the equipment, and even cause the equipment to fail to work normally; The flue gas must be dedusted by the bag filter before being discharged. Therefore, the material selection of the dust bag must take into account the high temperature of the flue gas, because the dust bag needs to be replaced every time it runs for a period of time, and the cost of the high temperature filter bag is high. The long-term operation cost of the system is high; if the low-temperature filter material is used, the system needs to be mixed with a large amount of wild wind, so that the flow rate of the fan increases and the power consumption increases; the tail gas with a higher flue gas temperature is directly discharged into the atmosphere, causing heat pollution to the environment at the same time , also wasting energy.

At present, there is no mature integration of rotary kiln waste heat recovery power generation and heat supply technology in China, but the use of heat collectors to recover flue gas waste heat is relatively mature; although ORC (organic refrigerant Rankine cycle) power generation technology has just started in my country, it is relatively mature. Mature, the use of ORC (organic refrigerant Rankine cycle) to develop a new type of high-efficiency low-temperature waste heat power generation system is of great significance for improving my country's energy utilization, energy conservation and emission reduction, and environmental protection.

Contents of the invention

The utility model provides a rotary kiln flue gas waste heat recovery and utilization device, which adopts a heat collector to recover the flue gas waste heat and adopts ORC technology to generate electricity; in the heating season, the heat supply for buildings is realized through the heat exchanger, and the rotary kiln preheating is fully utilized. Exhaust heat after the heater.

The technical scheme that the utility model adopts is:

A rotary kiln flue gas waste heat recovery and utilization device, including a heat collection device, a heat supply device and a water supply device;

The heat collection device includes: heat collector, high-temperature water circulation pump, high-temperature water constant pressure replenishment pump; the heat collector is equipped with a flue gas-water heat exchange system, and the heat collector is connected to the existing flue gas The pipeline, the inlet and outlet of the high-temperature water pipeline of the collector are connected with the heat exchanger, and the high-temperature water is sent to the heating device;

The heat supply device includes a heat exchanger, a heating circulation pump, and a heating constant-pressure supplementary water pump; the heat exchanger is connected with the heat collector to form a high-temperature water circulation loop, and the heat source of heat exchange comes from the heat collector, which supplies heat for heating users; The heater and the heating user form a heating water circulation loop;

The water replenishment device includes a water softener and a water softener replenishment pump; the water replenishment device realizes water supply for two systems of heat exchanger heating water and heat collector high-temperature water at the same time.

The above-mentioned rotary kiln flue gas waste heat recovery and utilization device also includes a power generation device. The power generation device includes an evaporator, a screw expander, and an evaporative condenser. The screw expander is connected to the generator; the evaporator is connected to the heat collector to form a high-temperature water circulation loop. , the screw expander is connected with the evaporator and the evaporative condenser to form an organic medium working medium power generation system; the evaporative condenser of the power generation device is connected with the water supply device.

Further, the evaporative condenser is connected to a water softener, and an evaporative condenser water replenishment pump is provided on the connecting pipeline.

In the above device, the heat exchanger is a plate heat exchanger or a shell and tube heat exchanger.

The beneficial effects brought by the rotary kiln flue gas waste heat recovery and utilization device provided by the utility model are as follows:

(1) It is suitable for waste heat recovery and utilization of newly built or renovated existing industrial rotary kilns, reducing thermal pollution of the original production system and significantly reducing pollutant emissions;

(2) After the recovery of waste heat in this scheme, the heat supply can be flexibly combined and connected with the ORC power generation device according to the actual needs of production and life, and the generated power can be reused in the original production system, reducing the amount of purchased electricity, and heating in winter can reduce other fuels and power consumption, saving energy;

(3) The rotary kiln described in the utility model can be used for calcining lime, light-burned dolomite, or industrial furnaces such as metallurgical pellets and cement.

Below in conjunction with accompanying drawing and embodiment the utility model is described further.

Description of drawings

Fig. 1 is the structural representation of embodiment 1.

Fig. 2 is the structural representation of embodiment 2.

In the figure, 1 is a heat collector, 2 is a high-temperature water circulation pump, 3 is a constant-pressure high-temperature water replenishment pump, 4a is an evaporator, 4b is a screw expander, 4c is a generator, 4d is an evaporative condenser, and 4e is a working fluid Pump, 5 is the plate heat exchanger, 6 is the heating circulation pump, 7 is the heating constant pressure water supply pump, 8 is the water softener, 9 is the water softener water supply pump, 10 is the evaporative condenser water supply pump, 11 is the flue gas inlet, 12 is a flue gas outlet, 13 is a flue gas pipeline, and 14 is a heating user.

detailed description

Example 1:

As shown in Figure 1, a rotary kiln flue gas waste heat recovery and utilization device includes a heat collection device, a power generation device, a heating device and a water supply device;

The heat collection device includes a heat collector 1, a high-temperature water circulation pump 2, and a high-temperature water constant pressure replenishment pump 3; The outlet 12 is connected to the existing flue gas pipeline 13, and the heat collector 1 is connected to the evaporator 4a and the plate heat exchanger 5 to send the high-temperature flue gas to the power generation device and the heating device;

The power generation device includes an evaporator 4a, a screw expander 4b, and an evaporative condenser 4d. The screw expander 4b is connected to the generator 4c; the evaporator 4a is connected to the heat collector 1 to form a circulation loop, and the screw expander 4b is connected to the evaporator 4a, The evaporative condenser 4d is connected to form a power generation system; and the evaporative condenser 4d is connected to the water supply device. The evaporative condenser 4d is connected to a water softener 8, and an evaporative condenser replenishment pump 10 is provided on the connecting pipeline;

The heat supply device includes a plate heat exchanger 5, a heating circulation pump 6, and a heating constant pressure supplementary water pump 7; the plate heat exchanger 5 is connected to the heat collector 1 to form a circulation loop, and the heat source of heat exchange comes from the heat collector 1, and the heat source is The heating user supplies heat, and the outlet of the plate heat exchanger 5 is connected to the heat collector 1; the heat source of the plate heat exchanger 5 forms a circulation loop with the heating user 14;

The water replenishment device includes a water softener 8 and a water softener replenishment pump 9; the water softener 8 supplies water to the plate heat exchanger 5 and the heat collector 1 .

The specific implementation method is:

The waste heat recovery method is based on the organic combination and integration of the three basic subsystems of the high-efficiency flue gas-water collector, ORC power generation device, and water-water heat exchanger system. Low-temperature waste flue gas waste heat power generation: 130°C (140°C)/70°C high-temperature water—F134a duplex circulation system; heat supply: 130°C (140°C)/70°C high-temperature water---75°C/ 60 ℃ secondary network heating water homogeneous dual parameter system.

High-efficiency flue gas-water collectors can be used to recover flue gas waste heat with 130°C (140°C)/70°C high-temperature hot water;

can achieve the above The high-temperature hot water of the recovered heat is 130°C (140°C)/70°C, and the 75°C/60°C secondary hot water network after heat exchange through the water-water heat exchanger supplies heat for buildings and provides life when needed. hot water for heating;

can achieve the above The high-temperature hot water of the recovered heat is 130°C (140°C)/70°C, and the ORC technology utilizes the organic refrigerant Rankine cycle to generate power;

It is also possible to achieve the above The high-temperature hot water of the recovered heat is 130°C (140°C)/70°C, and the ORC technology is used to generate electricity and heat the building at the same time, eliminating the necessary maintenance time to maximize waste heat recovery. The independent operation of power generation and heat supply can also be realized;

The 3×1000t/d active lime production line of Dongshan Limestone Mine of Shanxi Taigang Group is the most advanced active lime production technology in the world. It uses a rotary kiln system with vertical preheater and vertical cooler to calcinate active lime. In the production process of active lime, the hot gas at the tail end of the rotary kiln passes through the vertical preheater to preheat the limestone, and the temperature drops from 1000 to 1100°C to about 180°C, then enters the glass fiber bag filter for dust removal, and the dust content of the exhaust gas after dust removal is low. At 50mg/Nm ³ , it is discharged into the atmosphere through fans and chimneys, and the exhaust gas volume of each rotary kiln is about 200,000m ³ /h.

In order to realize the waste heat utilization of the rotary kiln, the flue gas system of the rotary kiln must be transformed. The specific method is: the exhaust gas pipe is drawn from the pipe from the outlet of the rotary kiln preheater to the dust collector and connected to the flue gas heat collector, and the original production system removes the dust collector. The flue gas pipe is used as a bypass flue, and electric flue valves are added on the inlet and outlet pipes of the collector to switch the air flow. The ash hopper is set at the lower part of the collector to collect ash, and the ash is regularly discharged by the star-shaped ash discharge valve. discharge. The low-temperature flue gas at the outlet of the heat collector is purified by the dust collector of the original waste gas treatment system and then discharged into the atmosphere. The high-temperature water enters the ORC generator room (which doubles as a heat exchange station) through pipelines. During the heating period, before entering the unit for power generation, the high-temperature water is diverted one way (flow rate is about 15.5t/h) to the plate heat exchanger and the heating hot water on the secondary side for heating. Exchange, the high temperature water drops from 140°C to 70°C, and the secondary side water rises from 60°C to 75°C. During the non-heating period, high-temperature water is only used to supply the generator set.

Low-temperature waste heat power generation is a dual-substance circulation system. A flue gas heat collector is installed on the flue gas side, and the high-temperature circulating water is used to heat the return water; an evaporator is installed on the organic working medium side, and the high-temperature circulating water is used to heat the organic working medium. The liquid organic working medium enters the evaporator after being boosted by the working medium pump, absorbs heat and is heated into saturated steam, then enters the screw expander to do work and drives the generator to generate electricity, and the exhausted steam discharged from the expander enters the condenser and is condensed into a liquid state , and then pumped into the evaporator through the working fluid to complete the cycle.

The heat supply is a homogeneous dual-parameter system. A flue gas collector is installed on the flue gas side, and the flue gas is used to heat the high-temperature circulating water return water; heat exchange is performed between the plate heat exchanger and the heating hot water on the secondary side, and the high-temperature water is supplied by the 140°C drops to 70°C, and the secondary side water rises from 60°C to 75°C.

The heat collector adopts the mature product of Luoyang Longhua. When the flue gas heat collector fails or the production system is abnormal, the collector can be disconnected by closing the inlet valve of the heat collector so that the air flows through the bypass flue. , which not only meets the stable operation of the lime production line, but also ensures the safety of the flue gas collector.

ORC generator adopts Zhejiang Kaishan screw expansion generator set.

Plate heat exchangers for heating are conventional plate heat exchangers, and regular manufacturers can meet the supply requirements.

Example 2:

As shown in Figure 2, a rotary kiln flue gas waste heat recovery and utilization device includes a heat collection device, a heat supply device and a water replenishment device;

The heat collection device includes a heat collector 1, a high-temperature water circulation pump 2, and a high-temperature water constant pressure replenishment pump 3; The outlet 12 is connected to the existing flue gas pipeline 13, and the heat collector 1 sends the high-temperature flue gas to the heating device;

The heat supply device includes a plate heat exchanger 5, a heating circulation pump 6, and a heating constant pressure supplementary water pump 7; the plate heat exchanger 5 is connected to the heat collector 1 to form a circulation loop, and the heat source of heat exchange comes from the heat collector 1, and the heat source is The heating user 14 supplies heat, and the outlet of the heat exchanger is connected to the heat collector 1; the plate heat exchanger 5 forms a circulation loop with the heating user;

The water replenishment device includes a water softener 8 and a water softener replenishment pump 9; the water softener 8 supplies water to the plate heat exchanger 5 and the heat collector 1 .

Shanxi Taigang Composite Material Factory currently has a 600t/d light-fired dolomite production line, and the air volume of the rotary kiln preheater is 60,000Nm ³ /h (actual operating temperature is about 240°C). It can use low-temperature waste heat utilization technology and set up a flue gas waste heat collector The heater can make full use of the waste heat of the flue gas to the maximum extent and generate hot water for heating. In this embodiment, an interface for future additional ORC power generation can be reserved. The heating area of this area is as high as 80,000 square meters ² , so in winter when the maximum heating load is reached, the pulverized coal boiler will bear the insufficient heating capacity. Within the heating scope of this project, all the old small boilers will be dismantled and replaced by building a heat exchange station and a boiler room. The process flow chart is shown in Figure 2.

Compared with Embodiment 1, this embodiment is completely the same except that there is no ORC generating set, so details will not be repeated.

According to the actual situation on site, the light-burned dolomite production line, through accounting and technical exchanges, uses a flue gas collector to cool the lime kiln flue gas temperature from 240°C to 100°C, and the collected heat can reduce 47.5t/ The hot water for h is heated from 70°C to 130°C.

In order to realize the waste heat utilization of the rotary kiln, the flue gas system of the rotary kiln must be transformed. The specific method is: the exhaust gas pipe is drawn from the pipe from the outlet of the rotary kiln preheater to the dust collector and connected to the flue gas heat collector, and the original production system removes the dust collector. The flue gas pipe is used as a bypass flue, and electric flue valves are added on the inlet and outlet pipes of the collector to switch the air flow. The ash hopper is set at the lower part of the collector to collect ash, and the ash is regularly discharged by the star-shaped ash discharge valve. discharge. The low-temperature flue gas at the outlet of the heat collector is purified by the dust collector of the original waste gas treatment system and then discharged into the atmosphere. In the heating period, high-temperature water enters the heat exchange station through the pipeline, and exchanges heat with the heating hot water on the secondary side of the plate heat exchanger. The high-temperature water drops from 130°C to 70°C, and the secondary side water rises from 50°C to 60 ℃. During the non-heating period, reserve high-temperature water to supply the interface of the generator set.

A flue gas collector is installed on the flue gas side, and the flue gas is used to heat the high-temperature circulating water return water; the heat supply is a homogeneous dual-parameter system, that is, heat exchange is performed between the plate heat exchanger and the heating hot water on the secondary side, and the high-temperature water From 130°C to 70°C, the secondary side water rises from 50°C to 60°C.

The heat collector adopts the mature product of Luoyang Longhua. When the flue gas heat collector fails or the production system is abnormal, the collector can be disconnected by closing the inlet valve of the heat collector so that the air flows through the bypass flue. , which not only meets the stable operation of the lime production line, but also ensures the safety of the flue gas collector.

Plate heat exchangers for heating are conventional plate heat exchangers, and regular manufacturers can meet the supply requirements.

The utility model is put on trial in Taiyuan Iron and Steel Composite Material Factory. It is expected to save 3806 tons of standard coal throughout the year, and the economic benefits are considerable; the annual emission of smoke and dust is reduced from 14.96t to 1.54t, and the annual emission of sulfur dioxide is reduced from 53.7t to 4.59t. The annual emission reductions of soot and sulfur dioxide were 13.42t and 49.11t respectively, and the pollutant emission was significantly reduced.

The utility model realizes cascade utilization of energy and reduces energy consumption of enterprises. The utility model especially utilizes the low-temperature waste heat of the light-fired dolomite rotary kiln, makes the low-grade waste heat resources play a role, and at the same time leaves an interface for the future implementation of combined heat and power supply, which is of great significance.

Claims (4)

1. a kind of rotary kiln flue gas heat recovery device it is characterised in that：Including heat collector, heating plant and moisturizing dress Put；

Heat collector includes：Heat collector, high temperature water-circulating pump, high-temperature water constant pressure supply water pump；Heat collector is provided with gas-water heat exchange system System, heat collector passes through gas approach, exhanst gas outlet connects existing flue, and heat collector high-temperature water pipeline is imported and exported and heat exchange Device connects, and high-temperature water is delivered in heating plant；

Heating plant includes heat exchanger, heating circulating pump, heating constant pressure supply water pump；Heat exchanger is connected formation high-temperature water with heat collector Closed circuit, heat exchange thermal source derives from heat collector, and this thermal source is heating user's heat supply；Heat exchanger forms heating water with heating user Closed circuit；

Water replanishing device includes water softener, water softener small pump；Described water replanishing device is heat exchanger heating water, heat collector high-temperature water two Individual system is realized supplying water simultaneously.

2. rotary kiln flue gas heat recovery device according to claim 1 it is characterised in that：Also include the dress that generates electricity Put, TRT includes vaporizer, screw expander, evaporative condenser, screw expander is connected with electromotor；Vaporizer with Heat collector connects formation high temperature water-flow circuit, and screw expander is connected formation organic media with vaporizer, evaporative condenser Working medium generating system；The evaporative condenser of this TRT is connected with water replanishing device.

3. rotary kiln flue gas heat recovery device according to claim 2 it is characterised in that：Described evaporating type condensing Device connects water softener, and is provided with evaporative condenser small pump on connecting line.

4. rotary kiln flue gas heat recovery device according to claim 1 it is characterised in that：Described heat exchanger is plate Formula heat exchanger or shell-and-tube heat exchanger.