CN110185508B - Energy comprehensive utilization system based on coal mine gas recovery and operation method thereof - Google Patents

Abstract

The invention discloses an energy comprehensive utilization system based on coal mine gas recovery and an operation method thereof, which are characterized by comprising the following steps: the system comprises a primary mixing device, a secondary mixing device, a heat storage oxidation device, a waste heat boiler, a steam turbine, a condenser, an air cooling island, a chimney, a smoke type absorption heat pump, a smoke heat exchanger, a first steam heat exchanger, a first water-repellent heat exchanger, a second steam heat exchanger, a second water-repellent heat exchanger and a coal mine shaft; the primary mixing device and the secondary mixing device are sequentially connected to provide a required low-concentration gas mixture for the heat storage oxidation device, and the heat storage oxidation device generates high-temperature flue gas which is recycled through the waste heat boiler and the steam turbine in sequence; in addition, the exhaust gas of the waste heat boiler and the high-temperature exhaust gas of the heat storage oxidation device are mixed to drive the flue gas type absorption heat pump. The invention deeply reduces the energy consumption of the whole system, reduces the loss of high-grade energy and realizes the cascade utilization of the heat energy.

Description

Energy comprehensive utilization system based on coal mine gas recovery and operation method thereof

Technical Field

The invention belongs to the field of coal mine low-concentration gas utilization and waste heat recovery, and particularly relates to a coal mine gas recovery-based energy comprehensive utilization system and an operation method thereof.

Background

Gas is the second only of the main greenhouse gas of carbon dioxide, and the greenhouse effect produced by unit mass of gas is equivalent to 21 times of that of the same mass of carbon dioxide. In coal mining, a large amount of gas is often associated at the same time, which is one of main gas industrial emission sources, so that the gas emission of a coal mine is reduced, and the emission of greenhouse gas can be effectively reduced. Meanwhile, the main component of coal mine gas is methane, which is a high-quality clean gas energy source.

China is a big energy consumption country, the energy yield of China in 2017 is 359000 ten thousand tons of standard coal, wherein the proportion of the natural gas yield in the total energy yield is continuously increased, and the natural gas yield is increased from 4.4% in 2013 to 5.4% in 2017. In recent years, the absolute quantity of extracted gas which is not utilized in China also tends to increase year by year, and the total quantity is huge. The unused pumping gas is mainly ultra-low concentration gas with concentration lower than 8%. At present, the pure methane discharged into the atmosphere through ventilation gas (ventilation air methane) in China every year is up to 100-150 hundred million Nm³The emission of methane accounts for 70 percent of the ventilation gas methane emission of coal mines in the world, which is equivalent to 1140-1700 million tons of standard coal. If the gas with different concentrations in the coal mine production process is collected and utilized, the gas accident of the coal mine can be effectively solved, the production living condition of a mining area is improved, the increase of clean energy supply and the reduction of greenhouse gas emission are facilitated, and the purposes of protecting life, saving resources and protecting environment are achievedMultiple goals of the environment are protected.

At present, the main utilization technical means of coal mine ventilation gas is a heat countercurrent heat accumulation oxidation technology, the core of the technology is high-temperature oxidation, heat accumulation recovery, periodic reversing and the like, and meanwhile, the technology is matched with the mixing and concentration control and regulation technology of ultralow-concentration extracted gas and air and ultralow-concentration extracted gas and ventilation air, so that the utilization range of the ultralow-concentration gas is greatly widened. However, currently, due to the great decrease of the income of the international Clean Development Mechanism (CDM), there is no economic benefit of pure ventilation air methane oxidation, for example, 6 ten thousand ventilation air methane oxidation projects of Chongqing Song algae mining bureau and Zheng coal group are both stopped. In addition, the oxygen content of hot wind discharged by the heat accumulation oxidation device is relatively high, and the hot wind can be fully recycled to meet other heat utilization requirements.

At present, the high-temperature flue gas waste heat recycling technology for discharging of the heat storage oxidation device mainly comprises: a mining area distributed coal mine gas near zero emission poly-generation energy supply system (patent number 201310201440.9), the main technical characteristics of the patent are: the high-concentration gas is directly used for driving a gas turbine to do work, the exhaust gas of the gas turbine is recycled by a waste heat boiler to generate steam to drive a steam turbine to do work, the exhaust gas of the gas turbine after being cooled is used for driving a waste heat type double-effect absorption cold and hot water unit to produce cold and hot water, and the low-concentration gas is oxidized to generate steam to drive the steam turbine to do work. The limitations of this patent technology mainly have: the exhaust waste heat of the oxidation device is not fully recycled, and the exhaust waste heat of the steam turbine is directly discharged and wasted. A distributed comprehensive function system for recycling passing gas (patent number 201810876396.4), the main technical characteristics of the patent are as follows: high-temperature flue gas is generated by gas oxidation, one part of the high-temperature flue gas is directly used for driving a flue gas type absorption refrigerating unit to refrigerate, the other part of the high-temperature flue gas generates steam through a waste heat boiler to drive a steam turbine to do work, and the steam extraction of the steam turbine is used for supplying heat. The technical limitation of the patent mainly comprises: the high-temperature flue gas generated by the oxidation device is directly utilized to be over high in temperature, and the flue gas type absorption refrigerating unit is driven to cause certain high-grade energy waste; the exhaust gas waste heat of the waste heat boiler is not fully recycled; the exhaust steam of the steam turbine is directly discharged and wasted; the steam drainage waste heat after heat supply by steam extraction and heat exchange is not recycled.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a coal mine gas recovery-based energy comprehensive utilization system with reasonable design and reliable performance and an operation method thereof.

The technical scheme adopted by the invention for solving the problems is as follows: this energy comprehensive utilization system based on colliery gas recovery, its characterized in that, it includes: the system comprises a primary mixing device, a secondary mixing device, a heat storage oxidation device, a waste heat boiler, a steam turbine, a condenser, an air cooling island, a chimney, a smoke type absorption heat pump, a smoke heat exchanger, a first steam heat exchanger, a first hydrophobic heat exchanger, a second steam heat exchanger, a second hydrophobic heat exchanger and a coal mine shaft, wherein the primary mixing device is provided with a smoke inlet, an air inlet and a gas inlet, the smoke inlet of the primary mixing device is connected with a low-temperature smoke outlet of the heat storage oxidation device, a second valve is arranged at the smoke inlet of the primary mixing device, the air inlet of the primary mixing device is connected with fresh air, a first valve is arranged at the air inlet of the primary mixing device, the gas inlet of the primary mixing device is connected with low-concentration gas, and the secondary mixing device is provided with a mixed gas inlet, a smoke inlet and an air inlet, the gas mixture import of secondary mixing device and mixing device's gas mixture exit linkage, and install first gas concentration measurement appearance in mixing device's gas mixture export, secondary mixing device's gas inlet and heat accumulation oxidation unit's low temperature exhanst gas outlet are connected, and install the fourth valve at secondary mixing device's gas mixture import, secondary mixing device's air inlet is connected with fresh air, and installs the third valve at secondary mixing device's air inlet, secondary mixing device's gas mixture export is connected with heat accumulation oxidation unit's air inlet, and installs second gas concentration measurement appearance at secondary mixing device's gas mixture export, heat accumulation oxidation unit's low temperature exhanst gas outlet still is connected with the chimney through low temperature flue pipe, and installs the fifth valve on low temperature flue pipe, heat accumulation oxidation unit's high temperature exhanst gas outlet through first high temperature flue gas branch pipe and second high temperature flue gas branch pipe respectively with waste heat A smoke inlet of the boiler is connected with a smoke inlet of the smoke absorption heat pump, a sixth valve and a seventh valve are respectively arranged on the first high-temperature smoke branch pipe and the second high-temperature smoke branch pipe, a smoke outlet of the waste heat boiler is respectively connected with the smoke inlet of the smoke absorption heat pump and the smoke inlet of the smoke heat exchanger through the first middle-temperature smoke branch pipe and the second middle-temperature smoke branch pipe, an eighth valve and a ninth valve are respectively arranged on the first middle-temperature smoke branch pipe and the second middle-temperature smoke branch pipe, a smoke outlet of the smoke absorption heat pump is connected with a chimney, a tenth valve is arranged at the smoke outlet of the smoke absorption heat pump, the smoke outlet of the smoke heat exchanger is connected with the chimney, an eleventh valve is arranged at the smoke outlet of the smoke heat exchanger, and an overheated steam outlet of the waste heat boiler is connected with a steam inlet of the steam turbine, the exhaust port of the steam turbine is connected with the exhaust steam inlet of the condenser, the condensed water outlet of the condenser is connected with the water inlet of the waste heat boiler, the circulating water inlet of the condenser is simultaneously connected with the circulating water outlet of the air cooling island and the low-temperature water outlet of the smoke-type absorption heat pump, a thirteenth valve and a fourteenth valve are respectively installed at the circulating water outlet of the air cooling island and the low-temperature water outlet of the smoke-type absorption heat pump, the circulating water outlet of the condenser is simultaneously connected with the circulating water inlet of the air cooling island and the low-temperature water inlet of the smoke-type absorption heat pump, a twelfth valve and a fifteenth valve are respectively installed at the circulating water inlet of the air cooling island and the low-temperature water inlet of the smoke-type absorption heat pump, the exhaust port of the steam turbine is simultaneously connected with the steam inlet of the first steam heat exchanger and the steam inlet of the second steam heat exchanger, and a seventeenth valve is respectively installed at the steam inlet of the first steam heat exchanger and the steam inlet of the The water outlet of the first steam heat exchanger is connected with the water inlet of the first water-repellent heat exchanger, the water outlet of the second steam heat exchanger is connected with the water inlet of the second water-repellent heat exchanger, the air inlet of the air cooling island is connected with cold air, a twenty-seventh valve is arranged at the air inlet of the air cooling island, the air outlet of the air cooling island is connected with the air inlet of the second water-repellent heat exchanger, the air outlet of the second water-repellent heat exchanger is connected with the air inlet of the second steam heat exchanger, the air outlet of the second steam heat exchanger is connected with the high-temperature air inlet of the coal mine shaft, a twenty-eighth valve is arranged at the air outlet of the second steam heat exchanger, the low-temperature air inlet of the coal mine shaft is connected with the cold air, and a twenty-sixth valve is arranged at the low-temperature air inlet of the coal mine shaft, the heat supply return pipe is simultaneously connected with the low-temperature water inlet of the flue gas heat exchanger, the medium-temperature water inlet of the flue gas absorption heat pump and the low-temperature water inlet of the first hydrophobic heat exchanger, an eighteenth valve, a twentieth valve and a twenty-twelfth valve are respectively arranged at the low-temperature water inlet of the flue gas heat exchanger, the medium-temperature water inlet of the flue gas absorption heat pump and the low-temperature water inlet of the first hydrophobic heat exchanger, the low-temperature water inlet of the first steam heat exchanger is simultaneously connected with the low-temperature water outlet of the flue gas heat exchanger, the medium-temperature water outlet of the flue gas absorption heat pump and the low-temperature water outlet of the first hydrophobic heat exchanger, and a nineteenth valve, a twenty-first valve, a twenty-third valve and a twenty-fourth valve are respectively arranged at the low-temperature water outlet of the flue gas heat exchanger, the medium-temperature water outlet of, the low-temperature water outlet of the first steam heat exchanger is connected with a heating water supply pipe, a twenty-fifth valve is installed at the low-temperature water outlet of the first steam heat exchanger, and the domestic hot water pipe is simultaneously connected with the low-temperature water outlet of the flue gas heat exchanger, the medium-temperature water outlet of the flue gas absorption heat pump and the low-temperature water outlet of the first hydrophobic heat exchanger.

Furthermore, the heat supply water return pipe is also connected with a water replenishing pipe, and a twenty-ninth valve is installed on the water replenishing pipe.

Further, the gas concentration in the mixed gas output by the primary mixing device is less than 3%, and the gas concentration in the mixed gas output by the secondary mixing device is less than 1.2%.

Furthermore, the flue gas heat exchanger, the flue gas type absorption heat pump and the first water-repellent heat exchanger are connected in parallel and then are connected with the first steam heat exchanger in series, hot water from the heat supply water return pipe simultaneously enters the flue gas heat exchanger, the flue gas type absorption heat pump and the first water-repellent heat exchanger, is heated by the first stage and then is output and mixed, one part of the hot water is used for providing domestic hot water for coal mine users through the domestic hot water pipe, and the other part of the hot water enters the first steam heat exchanger and is heated by the second stage and then is used for heating the coal mine users through the heating water supply pipe.

Further, the circulating water is used as a heating heat source of cold air and a low-temperature heat source of the smoke absorption heat pump at the same time.

Further, the air cooling island, the second hydrophobic heat exchanger and the second steam heat exchanger are sequentially connected in series, cold air firstly enters the air cooling island to be heated by the first stage, then enters the second hydrophobic heat exchanger to be heated by the second stage, and finally enters the second steam heat exchanger to be heated by the third stage.

Furthermore, the driving heat source of the smoke absorption heat pump comes from the exhaust-heat boiler and the heat storage oxidation device at the same time, and when the exhaust gas temperature of the exhaust-heat boiler is low, the high-temperature smoke of the heat storage oxidation device is mixed with the exhaust gas of the exhaust-heat boiler, so that the temperature of the smoke entering the smoke absorption heat pump is increased.

The operation method of the energy comprehensive utilization system based on coal mine gas recovery comprises the following steps:

opening and adjusting the first valve and the second valve, and performing first-stage mixing on the low-concentration gas, the low-temperature flue gas and the fresh air in a primary mixing device to form a gas mixed gas with the gas concentration of less than 3%;

opening and adjusting the third valve and the fourth valve, and carrying out second-stage mixing on the gas mixture from the primary mixing device, the low-temperature flue gas and the fresh air in the secondary mixing device to form the gas mixture with the gas concentration of less than 1.2%;

the gas mixture output by the secondary mixing device enters a heat storage oxidation device to be subjected to gas oxidation to form low-temperature flue gas and high-temperature flue gas, a fifth valve and a sixth valve are opened and adjusted, part of the low-temperature flue gas enters the primary mixing device and the secondary mixing device to be recycled, the other part of the low-temperature flue gas is discharged through a chimney, the high-temperature flue gas enters a waste heat boiler to be subjected to heat exchange to generate superheated steam, then the superheated steam enters a steam turbine to do work, the exhaust steam of the steam turbine enters a condenser to be condensed, and the formed condensed water returns to the waste heat boiler to be recycled;

in winter, when the outdoor temperature is low, closing the fourteenth valve and the fifteenth valve, opening and adjusting the sixteenth valve, the twenty-sixth valve, the twenty-seventh valve, the twenty-eighth valve, the twelfth valve and the thirteenth valve, enabling circulating water heated in the condenser to enter the air cooling island to carry out first-stage heating on cold air, enabling the heated cold air to enter the second water-repellent heat exchanger to be heated by the second stage, then carrying out third-stage heating on the cold air in the second steam heat exchanger by utilizing superheated steam extraction of the steam turbine, and finally conveying the heated cold air to the coal mine shaft to be mixed with the cold air so as to preserve heat of the coal mine shaft;

at the moment, a seventh valve, an eighth valve, a tenth valve, a twentieth valve and a twenty-first valve are closed, a ninth valve and an eleventh valve are opened, an eighteenth valve, a nineteenth valve, a twenty-second valve, a thirteenth valve, a twenty-fourth valve, a twenty-fifth valve and a seventeenth valve are opened and adjusted, hot water from a heat supply water return pipe simultaneously enters a flue gas heat exchanger and a first hydrophobic heat exchanger to be heated by a first stage and then is output and mixed, one part of hot water supplies domestic hot water to coal mine users through a domestic hot water pipe, and the other part of hot water enters a first steam heat exchanger to be heated by a second stage and then is supplied to the coal mine users through a heating water supply pipe;

and when the heat supply water pressure of the heat supply water return pipe is insufficient, opening the twenty-ninth valve, and supplementing water to the heat supply water return pipe through the water supplementing pipe.

In the operation method of the energy comprehensive utilization system based on coal mine gas recovery, the following steps are carried out:

in non-winter, when the outdoor temperature is higher, the twelfth valve, the thirteenth valve, the sixteenth valve, the twenty-seventh valve and the twenty-eighth valve are closed, the twenty-sixth valve is opened, and the cold air directly enters the coal mine shaft without being heated;

at the moment, opening a fourteenth valve and a fifteenth valve, opening and adjusting a seventh valve, an eighth valve, a ninth valve, a tenth valve, an eleventh valve, an eighteenth valve, a nineteenth valve, a twentieth valve and a twenty-first valve, closing a seventeenth valve, a twenty-second valve, a thirteenth valve, a twenty-fourth valve and a twenty-fifth valve, simultaneously feeding hot water from a heat supply water return pipe into a flue gas heat exchanger and a flue gas type absorption heat pump, heating the hot water by a first stage, outputting and mixing the hot water, and completely providing domestic hot water for coal mine users through a domestic hot water pipe;

and when the heat supply water pressure of the heat supply water return pipe is insufficient, opening the twenty-ninth valve, and supplementing water to the heat supply water return pipe through the water supplementing pipe.

Compared with the prior art, the invention has the following advantages and effects: reasonable in design, simple structure, the dependable performance, reasonable design is based on colliery gas recovery's energy comprehensive utilization system and operation method to the realization: (1) the low-temperature flue gas is used as a gas source required by mixing of the low-concentration gas, on one hand, the waste heat of the low-temperature flue gas is recycled, on the other hand, the fresh air consumption is saved, and the air compression energy consumption is reduced. (2) The method realizes the annual effective recycling of the exhaust waste heat of the steam turbine and reduces the overall energy consumption of the coal mine. (3) The high-temperature flue gas of the heat storage oxidation device and the medium-low temperature flue gas of the waste heat boiler are mixed to drive the flue gas type absorption heat pump, so that the consumption of high-grade flue gas energy is reduced, and the work capacity loss of the system is reduced. (4) According to the principle of 'temperature to mouth and cascade utilization', cold air, domestic hot water and heating water supply are heated in a cascade mode, so that low-grade energy of the system is fully recycled, and the work capacity loss in the heat exchange process is reduced. Therefore, the invention has great practical value.

Drawings

Fig. 1 is a schematic structural diagram of an energy comprehensive utilization system based on coal mine gas recovery in an embodiment of the invention.

Fig. 2 is a schematic structural view of the embodiment of the present invention during winter operation.

Fig. 3 is a schematic structural diagram of the embodiment of the invention during non-winter operation.

Detailed Description

The present invention will be described in further detail below by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not to be construed as limiting the present invention.

Examples are given.

Referring to fig. 1, the energy comprehensive utilization system based on coal mine gas recovery in the embodiment includes: the system comprises a primary mixing device 1, a secondary mixing device 2, a heat storage oxidation device 3, a waste heat boiler 4, a steam turbine 5, a condenser 6, an air cooling island 7, a chimney 8, a flue gas type absorption heat pump 9, a flue gas heat exchanger 10, a first steam heat exchanger 11, a first hydrophobic heat exchanger 12, a second steam heat exchanger 13, a second hydrophobic heat exchanger 14 and a coal mine shaft 15.

The primary mixing device 1 in the embodiment is provided with a flue gas inlet, an air inlet and a gas inlet, the flue gas inlet of the primary mixing device 1 is connected with a low-temperature flue gas outlet of the thermal storage oxidation device 3, the flue gas inlet of the primary mixing device 1 is provided with a second valve 22, the air inlet of the primary mixing device 1 is connected with fresh air 102, the air inlet of the primary mixing device 1 is provided with a first valve 21, the gas inlet of the primary mixing device 1 is connected with low-concentration gas 101, the secondary mixing device 2 is provided with a mixed gas inlet, a flue gas inlet and an air inlet, the mixed gas inlet of the secondary mixing device 2 is connected with the mixed gas outlet of the primary mixing device 1, the mixed gas outlet of the primary mixing device 1 is provided with a first gas concentration measuring instrument 23, the flue gas inlet of the secondary mixing device 2 is connected with the low-temperature flue gas outlet of the thermal, and a fourth valve 25 is installed at the flue gas inlet of the secondary mixing device 2, the air inlet of the secondary mixing device 2 is connected with fresh air 102, a third valve 24 is installed at the air inlet of the secondary mixing device 2, the mixed gas outlet of the secondary mixing device 2 is connected with the air inlet of the thermal storage oxidation device 3, and a second gas concentration measuring instrument 26 is installed at the mixed gas outlet of the secondary mixing device 2.

The low-temperature flue gas outlet of the thermal storage oxidation device 3 in this embodiment is further connected with the chimney 8 through a low-temperature flue gas pipe 61, and the fifth valve 27 is installed on the low-temperature flue gas pipe 61, the high-temperature flue gas outlet of the thermal storage oxidation device 3 is respectively connected with the flue gas inlet of the waste heat boiler 4 and the flue gas inlet of the flue gas type absorption heat pump 9 through a first high-temperature flue gas branch pipe 62 and a second high-temperature flue gas branch pipe 63, and the sixth valve 28 and the seventh valve 29 are respectively installed on the first high-temperature flue gas branch pipe 62 and the second high-temperature flue gas branch pipe 63, the flue gas outlet of the waste heat boiler 4 is respectively connected with the flue gas inlet of the flue gas type absorption heat pump 9 and the flue gas inlet of the flue gas heat exchanger 10 through a first medium-temperature flue gas branch pipe 64 and a second medium-temperature flue gas branch pipe 65, and the eighth valve 30 and the ninth valve 31, the flue gas outlet of the flue gas type absorption heat pump 9 is connected with the chimney 8, the tenth valve 32 is installed at the flue gas outlet of the flue gas type absorption heat pump 9, the flue gas outlet of the flue gas heat exchanger 10 is connected with the chimney 8, and the eleventh valve 33 is installed at the flue gas outlet of the flue gas heat exchanger 10.

In this embodiment, the superheated steam outlet of the exhaust-heat boiler 4 is connected to the steam inlet of the steam turbine 5, the steam outlet of the steam turbine 5 is connected to the exhaust steam inlet of the condenser 6, the condensed water outlet of the condenser 6 is connected to the water inlet of the exhaust-heat boiler 4, the circulating water inlet of the condenser 6 is simultaneously connected to the circulating water outlet of the air cooling island 7 and the low-temperature water outlet of the flue gas type absorption heat pump 9, a thirteenth valve 35 and a fourteenth valve 36 are respectively installed at the circulating water outlet of the air cooling island 7 and the low-temperature water outlet of the flue gas type absorption heat pump 9, the circulating water outlet of the condenser 6 is simultaneously connected to the circulating water inlet of the air cooling island 7 and the low-temperature water inlet of the flue gas type absorption heat pump 9, a twelfth valve 34 and a fifteenth valve 37 are respectively installed at the circulating water inlet of the air cooling island 7 and the low-temperature water inlet of the flue gas type absorption heat pump 9, and the steam outlet of the steam turbine 5 is simultaneously connected to the steam inlet of the first steam The steam inlet is connected, a seventeenth valve 39 and a sixteenth valve 38 are respectively installed at the steam inlet of the first steam heat exchanger 11 and the steam inlet of the second steam heat exchanger 13, the hydrophobic outlet of the first steam heat exchanger 11 is connected with the hydrophobic inlet of the first hydrophobic heat exchanger 12, and the hydrophobic outlet of the second steam heat exchanger 13 is connected with the hydrophobic inlet of the second hydrophobic heat exchanger 14.

In this embodiment, the air inlet of the air cooling island 7 is connected with cold air 103, the air inlet of the air cooling island 7 is provided with a twenty-seventh valve 49, the air outlet of the air cooling island 7 is connected with the air inlet of the second hydrophobic heat exchanger 14, the air outlet of the second hydrophobic heat exchanger 14 is connected with the air inlet of the second steam heat exchanger 13, the air outlet of the second steam heat exchanger 13 is connected with the high-temperature air inlet of the coal mine shaft 15, the air outlet of the second steam heat exchanger 13 is provided with a twenty-eighth valve 50, the low-temperature air inlet of the coal mine shaft 15 is connected with the cold air 103, the low-temperature air inlet of the coal mine shaft 15 is provided with a twenty-sixth valve 48, the heat supply water return pipe 66 is simultaneously connected with the low-temperature water inlet of the flue gas heat exchanger 10, the medium-temperature water inlet of the flue gas absorption heat pump 9 and the low-temperature water inlet of the first hydrophobic heat exchanger, An eighteenth valve 40, a twentieth valve 42 and a twentieth valve 44 are respectively installed at the medium temperature water inlet of the flue gas type absorption heat pump 9 and the low temperature water inlet of the first hydrophobic heat exchanger 12.

In this embodiment, the low-temperature water inlet of the first steam heat exchanger 11 is connected to the low-temperature water outlet of the flue gas heat exchanger 10, the medium-temperature water outlet of the flue gas absorption heat pump 9 and the low-temperature water outlet of the first water-repellent heat exchanger 12 at the same time, a nineteenth valve 41, a twenty-first valve 43, a twenty-third valve 45 and a twenty-fourth valve 46 are respectively installed at the low-temperature water outlet of the flue gas heat exchanger 10, the medium-temperature water outlet of the flue gas absorption heat pump 9, the low-temperature water outlet of the first water-repellent heat exchanger 12 and the low-temperature water inlet of the first steam heat exchanger 11, the low-temperature water outlet of the first steam heat exchanger 11 is connected to a heating water supply pipe 69, a twenty-fifth valve 47 is installed at the low-temperature water outlet of the first steam heat exchanger 11, a domestic hot water pipe 68 is connected to the low-temperature water outlet of the flue gas heat exchanger, the heat supply water return pipe 66 is also connected with a water replenishing pipe 67, and a twenty-ninth valve 51 is installed on the water replenishing pipe 67.

In this embodiment, the gas concentration in the mixed gas output by the first blending device 1 is less than 3%, and the gas concentration in the mixed gas output by the second blending device 2 is less than 1.2%.

In the present embodiment, the circulating water serves as a heating heat source for the cold air 103 and a low-temperature heat source for the flue gas type absorption heat pump 9 at the same time.

In this embodiment, the driving heat source of the flue gas type absorption heat pump 9 comes from the exhaust-heat boiler 4 and the thermal storage oxidation device 3 at the same time, and when the exhaust gas temperature of the exhaust-heat boiler 4 is low, the high-temperature flue gas of the thermal storage oxidation device 3 is mixed with the exhaust gas of the exhaust-heat boiler 4, so as to increase the temperature of the flue gas entering the flue gas type absorption heat pump 9.

Referring to fig. 2, the operation method of the energy comprehensive utilization system based on coal mine gas recovery according to the embodiment is as follows:

in winter, when the outdoor air temperature is low:

opening and adjusting a first valve 21 and a second valve 22, and performing first-stage mixing on low-concentration gas 101, low-temperature flue gas and fresh air 102 in a primary mixing device 1 to form gas mixture with the gas concentration of less than 3%;

opening and adjusting the third valve 24 and the fourth valve 25, and performing second-stage mixing on the gas mixture from the primary mixing device 1, the low-temperature flue gas and the fresh air 102 in the secondary mixing device 2 to form a gas mixture with the gas concentration of less than 1.2%;

the gas mixture output by the secondary mixing device 2 enters the heat accumulation oxidation device 3 to be subjected to gas oxidation to form low-temperature flue gas and high-temperature flue gas, a fifth valve 27 and a sixth valve 28 are opened and adjusted, a part of the low-temperature flue gas enters the primary mixing device 1 and the secondary mixing device 2 to be recycled, the other part of the low-temperature flue gas is discharged through a chimney 8, the high-temperature flue gas enters the waste heat boiler 4 to be subjected to heat exchange to generate superheated steam, then enters the steam turbine 5 to do work, the exhaust steam of the steam turbine 5 enters the condenser 6 to be condensed, and the formed condensed water returns to the waste heat boiler 4 to be recycled;

closing the fourteenth valve 36 and the fifteenth valve 37, opening and adjusting the sixteenth valve 38, the twenty-sixth valve 48, the twenty-seventh valve 49, the twenty-eighth valve 50, the twelfth valve 34 and the thirteenth valve 35, allowing circulating water heated in the condenser 6 to enter the air cooling island 7 to perform first-stage heating on cold air, allowing the heated cold air 103 to enter the second water-repellent heat exchanger 14 to be heated by a second stage, performing third-stage heating on the cold air in the second steam heat exchanger 13 by using superheated steam extracted by the steam turbine 5, and finally conveying the heated cold air to the coal mine shaft 15 to be mixed with the cold air 103, so as to preserve heat of the coal mine shaft 15;

at this time, the seventh valve 29, the eighth valve 30, the tenth valve 32, the twentieth valve 42 and the twenty-first valve 43 are closed, the ninth valve 31 and the eleventh valve 33 are opened, the eighteenth valve 40, the nineteenth valve 41, the twentieth valve 44, the twentieth valve 45, the twenty-fourth valve 46, the twenty-fifth valve 47 and the seventeenth valve 39 are opened and adjusted, the hot water from the heat supply water return pipe 66 simultaneously enters the flue gas heat exchanger 10 and the first water-repellent heat exchanger 12 to be heated by the first stage and then output to be mixed, one part of the hot water is used for providing the hot water for the coal mine users through the hot water pipe 68, the other part of the hot water enters the first steam heat exchanger 11 again to be heated by the second stage and then is used for heating the coal mine users through the;

when the pressure of the heating water in the heating water return pipe 66 is insufficient, the twenty-ninth valve 51 is opened, and water is supplied to the heating water return pipe 66 through the water supply pipe 67.

Referring to fig. 3, another operation method of the energy comprehensive utilization system based on coal mine gas recovery according to the embodiment is as follows:

in non-winter, when outdoor temperature is higher:

opening and adjusting a third valve 24 and a fourth valve 25, and carrying out second-stage mixing on the gas mixture from the primary mixing device 1, the low-temperature flue gas and the fresh air in a secondary mixing device 2 to form gas mixture with the gas concentration of less than 1.2%;

the gas mixture output by the secondary mixing device 2 enters the heat accumulation oxidation device 3 to be subjected to gas oxidation to form low-temperature flue gas and high-temperature flue gas, a fifth valve 27 and a sixth valve 28 are opened and adjusted, a part of the low-temperature flue gas enters the primary mixing device 1 and the secondary mixing device 2 to be recycled, the other part of the low-temperature flue gas is discharged through a chimney 8, the high-temperature flue gas enters the waste heat boiler 4 to be subjected to heat exchange to generate superheated steam, then enters the steam turbine 5 to do work, the exhaust steam of the steam turbine 5 enters the condenser 6 to be condensed, and the formed condensed water returns to the waste heat boiler 4 to be recycled;

closing the twelfth valve 34, the thirteenth valve 35, the sixteenth valve 38, the twenty-seventh valve 49 and the twenty-eighth valve 50, and opening the twenty-sixth valve 48, so that the cold air can directly enter the coal mine shaft 15 without being heated;

at this time, the fourteenth valve 36 and the fifteenth valve 37 are opened, the seventh valve 29, the eighth valve 30, the ninth valve 31, the tenth valve 32, the eleventh valve 33, the eighteenth valve 40, the nineteenth valve 41, the twentieth valve 42 and the twenty-first valve 43 are opened and adjusted, the seventeenth valve 39, the twelfth valve 44, the twentieth valve 45, the twenty-fourth valve 46 and the twenty-fifth valve 47 are closed, the hot water from the heat supply water return pipe 66 simultaneously enters the flue gas heat exchanger 10 and the flue gas absorption heat pump 9, is heated by the first stage and then is output and mixed, and all the hot water is used for providing domestic hot water for coal mine users through the domestic hot water pipe 68;

when the pressure of the heating water in the heating water return pipe 66 is insufficient, the twenty-ninth valve 51 is opened, and water is supplied to the heating water return pipe 66 through the water supply pipe 67.

In addition, it should be noted that the specific embodiments described in the present specification may be different in the components, the shapes of the components, the names of the components, and the like, and the above description is only an illustration of the structure of the present invention. Equivalent or simple changes in the structure, characteristics and principles of the invention are included in the protection scope of the patent. Various modifications, additions and substitutions for the specific embodiments described may be made by those skilled in the art without departing from the scope of the invention as defined in the accompanying claims.

Claims (9)

1. The utility model provides an energy comprehensive utilization system based on colliery gas recovery which characterized in that includes: the system comprises a primary mixing device (1), a secondary mixing device (2), a heat storage oxidation device (3), a waste heat boiler (4), a steam turbine (5), a condenser (6), an air cooling island (7), a chimney (8), a smoke type absorption heat pump (9), a smoke heat exchanger (10), a first steam heat exchanger (11), a first hydrophobic heat exchanger (12), a second steam heat exchanger (13), a second hydrophobic heat exchanger (14) and a coal mine shaft (15), wherein the primary mixing device (1) is provided with a smoke inlet, an air inlet and a gas inlet, the smoke inlet of the primary mixing device (1) is connected with a low-temperature smoke outlet of the heat storage oxidation device (3), a second valve (22) is arranged at the smoke inlet of the primary mixing device (1), and the air inlet of the primary mixing device (1) is connected with fresh air (102), a first valve (21) is arranged at an air inlet of the primary mixing device (1), a gas inlet of the primary mixing device (1) is connected with low-concentration gas (101), a mixed gas inlet, a flue gas inlet and an air inlet are arranged on the secondary mixing device (2), the mixed gas inlet of the secondary mixing device (2) is connected with a mixed gas outlet of the primary mixing device (1), a first gas concentration measuring instrument (23) is arranged at a mixed gas outlet of the primary mixing device (1), the flue gas inlet of the secondary mixing device (2) is connected with a low-temperature flue gas outlet of the heat accumulation oxidation device (3), a fourth valve (25) is arranged at the flue gas inlet of the secondary mixing device (2), the air inlet of the secondary mixing device (2) is connected with fresh air (102), and a third valve (24) is arranged at the air inlet of the secondary mixing device (2), the mixed gas outlet of the secondary mixing device (2) is connected with the gas inlet of the heat-storage oxidation device (3), the second gas concentration measuring instrument (26) is installed at the mixed gas outlet of the secondary mixing device (2), the low-temperature gas outlet of the heat-storage oxidation device (3) is connected with a chimney (8) through a low-temperature gas pipe (61), a fifth valve (27) is installed on the low-temperature gas pipe (61), the high-temperature gas outlet of the heat-storage oxidation device (3) is connected with the gas inlet of the waste heat boiler (4) and the gas inlet of the gas type heat pump (9) through a first high-temperature gas branch pipe (62) and a second high-temperature gas branch pipe (63), a sixth valve (28) and a seventh valve (29) are installed on the first high-temperature gas branch pipe (62) and the second high-temperature gas branch pipe (63), and the gas outlet of the waste heat boiler (4) is connected with the gas inlet of the waste heat boiler (4) and the absorption type heat pump (9) through a first medium- 65) Respectively connected with a flue gas inlet of a flue gas type absorption heat pump (9) and a flue gas inlet of a flue gas heat exchanger (10), and respectively provided with an eighth valve (30) and a ninth valve (31) on a first medium-temperature flue gas branch pipe (64) and a second medium-temperature flue gas branch pipe (65), a flue gas outlet of the flue gas type absorption heat pump (9) is connected with a chimney (8), a tenth valve (32) is arranged at a flue gas outlet of the flue gas type absorption heat pump (9), a flue gas outlet of the flue gas heat exchanger (10) is connected with the chimney (8), an eleventh valve (33) is arranged at a flue gas outlet of the flue gas heat exchanger (10), an overheated steam outlet of the waste heat boiler (4) is connected with a steam inlet of a steam turbine (5), a steam outlet of the steam turbine (5) is connected with an exhausted steam inlet of a condenser (6), a condensed water outlet of the condenser (6) is connected with a water inlet of the waste heat boiler (4), a circulating water inlet of the condenser (6) is connected with a circulating water outlet of the air cooling island (7) and a low-temperature water outlet of the smoke absorption heat pump (9) at the same time, a thirteenth valve (35) and a fourteenth valve (36) are respectively installed at the circulating water outlet of the air cooling island (7) and the low-temperature water outlet of the smoke absorption heat pump (9), a circulating water outlet of the condenser (6) is connected with the circulating water inlet of the air cooling island (7) and the low-temperature water inlet of the smoke absorption heat pump (9) at the same time, a twelfth valve (34) and a fifteenth valve (37) are respectively installed at the circulating water inlet of the air cooling island (7) and the low-temperature water inlet of the smoke absorption heat pump (9), a steam extraction port of the steam turbine (5) is connected with a steam inlet of the first steam heat exchanger (11) and a steam inlet of the second steam heat exchanger (13) at the same time, a seventeenth valve (39) and a sixteenth valve (38) are respectively arranged at a steam inlet of the first steam heat exchanger (11) and a steam inlet of the second steam heat exchanger (13), a hydrophobic outlet of the first steam heat exchanger (11) is connected with a hydrophobic inlet of the first hydrophobic heat exchanger (12), a hydrophobic outlet of the second steam heat exchanger (13) is connected with a hydrophobic inlet of the second hydrophobic heat exchanger (14), an air inlet of the air cooling island (7) is connected with cold air (103), a twenty-seventh valve (49) is arranged at the air inlet of the air cooling island (7), an air outlet of the air cooling island (7) is connected with an air inlet of the second hydrophobic heat exchanger (14), an air outlet of the second hydrophobic heat exchanger (14) is connected with an air inlet of the second steam heat exchanger (13), and an air outlet of the second steam heat exchanger (13) is connected with a high-temperature air inlet of the coal mine shaft (15), and a twenty-eighth valve (50) is installed at an air outlet of the second steam heat exchanger (13), a low-temperature air inlet of the coal mine shaft (15) is connected with cold air (103), a twenty-sixth valve (48) is installed at a low-temperature air inlet of the coal mine shaft (15), a heat supply water return pipe (66) is simultaneously connected with a low-temperature water inlet of the flue gas heat exchanger (10), a medium-temperature water inlet of the flue gas absorption heat pump (9) and a low-temperature water inlet of the first hydrophobic heat exchanger (12), and an eighteenth valve (40), a twentieth valve (42) and a twenty-twelfth valve (44) are respectively installed at the low-temperature water inlet of the flue gas heat exchanger (10), the medium-temperature water inlet of the flue gas absorption heat pump (9) and the low-temperature water inlet of the first hydrophobic heat exchanger (12), the low-temperature water inlet of the first steam heat exchanger (11) is simultaneously connected with a, The middle temperature water outlet of the smoke absorption heat pump (9) is connected with the low temperature water outlet of the first hydrophobic heat exchanger (12), and a nineteenth valve (41), a twenty-first valve (43), a twenty-third valve (45) and a twenty-fourth valve (46) are respectively arranged at the low-temperature water outlet of the flue gas heat exchanger (10), the medium-temperature water outlet of the flue gas absorption heat pump (9), the low-temperature water outlet of the first hydrophobic heat exchanger (12) and the low-temperature water inlet of the first steam heat exchanger (11), the low-temperature water outlet of the first steam heat exchanger (11) is connected with a heating water supply pipe (69), and a twenty-fifth valve (47) is installed at a low-temperature water outlet of the first steam heat exchanger (11), and a domestic hot water pipe (68) is simultaneously connected with a low-temperature water outlet of the flue gas heat exchanger (10), a medium-temperature water outlet of the flue gas absorption heat pump (9) and a low-temperature water outlet of the first hydrophobic heat exchanger (12).

2. The energy comprehensive utilization system based on coal mine gas recovery as claimed in claim 1, wherein the heat supply water return pipe (66) is further connected with a water replenishing pipe (67), and a twenty-ninth valve (51) is mounted on the water replenishing pipe (67).

3. The energy comprehensive utilization system based on coal mine gas recovery as claimed in claim 1, wherein the gas concentration in the mixed gas output by the primary blending device (1) is less than 3%, and the gas concentration in the mixed gas output by the secondary blending device (2) is less than 1.2%.

4. The energy comprehensive utilization system based on coal mine gas recovery as claimed in claim 1, wherein the flue gas heat exchanger (10), the flue gas absorption heat pump (9) and the first water-repellent heat exchanger (12) are connected in parallel and then connected in series with the first steam heat exchanger (11) at the same time, hot water from the heat supply water return pipe (66) simultaneously enters the flue gas heat exchanger (10), the flue gas absorption heat pump (9) and the first water-repellent heat exchanger (12) to be heated by the first stage and then output and mixed, one part of the hot water is used for providing domestic hot water for coal mine users through a domestic hot water pipe (68), and the other part of the hot water is used for heating the coal mine users through a heating water supply pipe (69) after entering the first steam heat exchanger (11) to be heated by the second stage.

5. The energy comprehensive utilization system based on coal mine gas recovery as claimed in claim 1, wherein the circulating water is used as a heating heat source of cold air (103) and a low-temperature heat source of the flue gas type absorption heat pump (9) at the same time.

6. The energy comprehensive utilization system based on coal mine gas recovery according to claim 1, wherein the air cooling island (7), the second water-repellent heat exchanger (14) and the second steam heat exchanger (13) are sequentially connected in series, cold air firstly enters the air cooling island (7) and is heated by a first stage, then enters the second water-repellent heat exchanger (14) and is heated by a second stage, and finally enters the second steam heat exchanger (13) and is heated by a third stage.

7. The energy comprehensive utilization system based on coal mine gas recovery according to claim 1, wherein the driving heat source of the flue gas type absorption heat pump (9) comes from the waste heat boiler (4) and the heat storage oxidation device (3) at the same time, and when the exhaust gas temperature of the waste heat boiler (4) is low, the high-temperature flue gas of the heat storage oxidation device (3) is mixed with the exhaust gas of the waste heat boiler (4) to increase the temperature of the flue gas entering the flue gas type absorption heat pump (9).

8. An operation method of the energy comprehensive utilization system based on coal mine gas recovery according to any one of claims 1 to 7, characterized by comprising the following steps:

opening and adjusting a first valve (21) and a second valve (22), and performing first-stage mixing on low-concentration gas (101), low-temperature flue gas and fresh air (102) in a primary mixing device (1) to form gas mixture with the gas concentration of less than 3%;

opening and adjusting a third valve (24) and a fourth valve (25), and carrying out second-stage mixing on the gas mixture from the primary mixing device (1), the low-temperature flue gas and the fresh air (102) in a secondary mixing device (2) to form the gas mixture with the gas concentration of less than 1.2%;

the gas mixture output by the secondary mixing device (2) enters a heat storage oxidation device (3) to be subjected to gas oxidation to form low-temperature flue gas and high-temperature flue gas, a fifth valve (27) and a sixth valve (28) are opened and adjusted, a part of the low-temperature flue gas enters the primary mixing device (1) and the secondary mixing device (2) to be recycled, the other part of the low-temperature flue gas is discharged outwards through a chimney (8), the high-temperature flue gas enters a waste heat boiler (4) to be subjected to heat exchange to generate superheated steam, then enters a steam turbine (5) to do work, the exhaust steam of the steam turbine (5) enters a condenser (6) to be condensed, and the formed condensed water returns to the waste heat boiler (4) to be recycled;

in winter, when the outdoor air temperature is low, closing a fourteenth valve (36) and a fifteenth valve (37), opening and adjusting a sixteenth valve (38), a twenty sixth valve (48), a twenty seventh valve (49), a twenty eighth valve (50), a twelfth valve (34) and a thirteenth valve (35), feeding circulating water heated in a condenser (6) into an air cooling island (7) to carry out first-stage heating on cold air (103), feeding the heated cold air into a second hydrophobic heat exchanger (14) to be heated by a second stage, then carrying out third-stage heating on the cold air in a second steam heat exchanger (13) by using superheated steam of a steam turbine (5), and finally conveying the heated cold air to a coal mine shaft (15) to be mixed with the cold air (103) so as to preserve the heat of the coal mine shaft (15);

at the moment, the seventh valve (29), the eighth valve (30), the tenth valve (32), the twentieth valve (42) and the twenty-first valve (43) are closed, the ninth valve (31) and the eleventh valve (33) are opened, the eighteenth valve (40), the nineteenth valve (41), the twelfth valve (44), the thirteenth valve (45), the twenty-fourth valve (46), the twenty-fifth valve (47) and the seventeenth valve (39) are opened and adjusted, hot water from the heat supply water return pipe (66) simultaneously enters the flue gas heat exchanger (10) and the first water drainage heat exchanger (12) and is heated by the first stage and then output and mixed, one part of the hot water supplies domestic hot water for coal mine users through a domestic hot water pipe (68), and the other part of the hot water enters the first steam heat exchanger (11) and is heated by the second stage and then supplies heat for the coal mine users through a heating water supply pipe (69);

when the heat supply water pressure of the heat supply water return pipe (66) is insufficient, the twenty-ninth valve (51) is opened, and water is supplemented to the heat supply water return pipe (66) through the water supplementing pipe (67).

9. The method of operating a coal mine gas recovery based energy recovery integrated utilization system according to claim 8, wherein:

in non-winter, when the outdoor temperature is higher, the twelfth valve (34), the thirteenth valve (35), the sixteenth valve (38), the twenty-seventh valve (49) and the twenty-eighth valve (50) are closed, the twenty-sixth valve (48) is opened, and the cold air can directly enter the coal mine shaft (15) without being heated;

at the moment, a fourteenth valve (36) and a fifteenth valve (37) are opened, a seventh valve (29), an eighth valve (30), a ninth valve (31), a tenth valve (32), an eleventh valve (33), an eighteenth valve (40), a nineteenth valve (41), a twentieth valve (42) and a twenty-first valve (43) are opened and adjusted, a seventeenth valve (39), a twelfth valve (44), a thirteenth valve (45), a twenty-fourth valve (46) and a twenty-fifth valve (47) are closed, hot water from a heat supply water return pipe (66) simultaneously enters a flue gas heat exchanger (10) and a flue gas type absorption heat pump (9) and is heated by a first stage and then output and mixed, and all the hot water supplies life hot water to coal mine users through a hot water pipe (68);

when the heat supply water pressure of the heat supply water return pipe (66) is insufficient, the twenty-ninth valve (51) is opened, and water is supplemented to the heat supply water return pipe (66) through the water supplementing pipe (67).

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