Waste heat utilization system and waste heat utilization method of coke oven gas

Abstract

The invention discloses a coke oven gas waste heat utilization system and a waste heat utilization method. The coke oven gas waste heat utilization system comprises a circulating ammonia water pump, one side of the circulating ammonia water pump is connected with a refrigerating unit, the refrigerating unit is connected with a bridge pipe and an ascending pipe through pipelines, one side of the bridge pipe is connected with a gas collecting pipe, and the gas collecting pipe is connected with a gas-liquid separator. The device has the beneficial effects that the technology of preparing low-temperature water by taking the residual ammonia water as a heat source after heat exchange between the residual ammonia water and the coke oven gas and the double-effect heat pump technology of taking heat source water after indirect heat exchange between the double-effect heat pump unit and the coal gas at the upper section of the primary cooler as a heat source are utilized, so that the coke oven gas waste heat utilization efficiency is improved, and coal gas purification and deep processing utilization are facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of chemical equipment, and in particular to a waste heat utilization system of coke oven gas. Background Art

[0002] In order to ensure the yield of chemical products and the normal operation of the coke oven gas system, the gas temperature needs to be lowered to 19-25℃. The original process is to absorb and carry away the gas by circulating water and cool it naturally by cooling towers, sometimes assisted by cooling fans, which not only wastes this part of energy, but also requires a part of kinetic energy to cool the process circulating water, consuming a certain amount of water. On the other hand, there is insufficient cooling water in the chemical production system in high temperature seasons, resulting in high gas temperature, which in turn reduces the yield of chemical products and affects the utilization efficiency of coke oven gas in the subsequent system. In low temperature seasons, the demand for thermal energy water such as steam is large, and our company has a gap of 7t / h. Therefore, the existing process not only leads to heat waste, but also increases environmental pressure and wastewater treatment costs. Summary of the invention

[0003] The purpose of the present invention is to provide a waste heat utilization system and waste heat utilization method of coke oven gas in order to solve the above problems.

[0004] The present invention achieves the above-mentioned purpose through the following technical solutions: A waste heat utilization system for coke oven gas comprises a circulating ammonia water pump, one side of the circulating ammonia water pump is connected to a refrigeration unit, the refrigeration unit is connected to a bridge pipe and a riser through a pipeline, one side of the bridge pipe is connected to a gas collecting pipe, the gas collecting pipe is connected to a gas-liquid separator, one side of the gas-liquid separator is connected to a circulating ammonia water static oil removal device, the other side of the circulating ammonia water pump is connected to the circulating ammonia water static oil removal device, the other side of the gas-liquid separator is connected to a primary cooler, the primary cooler is connected to a heat source water pump and a double-effect heat pump unit through a pipeline, the primary cooler is connected to the double-effect heat pump unit through a heat source water return pipeline, the refrigeration unit and the double-effect heat pump unit are connected to a low-temperature water network through a pipeline, and the double-effect heat pump unit is connected to a hot water network.

[0005] Furthermore, the refrigeration unit is provided with two groups, the heat source inlet end of the refrigeration unit is connected to the outlet end of the circulating ammonia water pump through a pipeline, and the heat source outlet end of the refrigeration unit is connected to the inlet end of the bridge pipe and the outlet end of the riser through a pipeline.

[0006] Furthermore, the inlet end of the gas collecting pipe is connected to the outlet end of the bridge pipe through a pipeline, and the outlet end of the gas collecting pipe is connected to the inlet end of the gas-liquid separator through a pipeline.

[0007] Furthermore, the liquid phase outlet of the gas-liquid separator is connected to the inlet of the circulating ammonia static oil removal device through a pipeline, and the gas phase outlet of the gas-liquid separator is connected to the coke oven gas inlet of the primary cooler through a pipeline.

[0008] Furthermore, the circulating ammonia water outlet end of the circulating ammonia water static oil removal device is connected to the inlet end of the circulating ammonia water pump through a pipeline.

[0009] Furthermore, the inlet end of the water jacket of the upper section of the pre-cooler is connected to the outlet end of the heat source water pump through a pipeline, the inlet end of the heat source water pump is connected to the heat source outlet end of the double-effect heat pump unit through a pipeline, and the outlet end of the water jacket of the upper section of the pre-cooler is connected to the heat source inlet end of the double-effect heat pump unit through a heat source water return pipeline.

[0010] Furthermore, the cold water outlet end of the refrigeration unit and the cold water outlet end of the double-effect heat pump unit are connected to the low-temperature water network through pipes, and the hot water outlet end of the double-effect heat pump unit is connected to the hot water network through pipes.

[0011] The waste heat utilization method of the present invention comprises the following steps: S1. The coke oven gas entering from the riser is mixed with the sprayed circulating ammonia water at the bridge pipe and then enters the gas collecting pipe. The coke oven gas and the circulating ammonia water are separated by the gas-liquid separator. The separated circulating ammonia water is degreased by the circulating ammonia water static degreasing device. After degreasing, it is pressurized by the circulating ammonia water pump and enters the refrigeration unit as a heat source for heat exchange to produce low-temperature water. The circulating ammonia water coming out of the refrigeration unit is mixed with the coke oven gas entering from the riser at the bridge pipe again and enters the next cycle. S2. The coke oven gas with a temperature of 80°C after separation at the gas-liquid separator exchanges heat with the heat source water jacket of the double-effect heat pump unit in the upper section of the primary cooler. The heat source water of 78°C after absorbing heat enters the double-effect heat pump unit to provide heat source. The double-effect heat pump unit produces 16°C low-temperature water in the cooling mode or 110°C hot water in the heating mode. The heat source water coming out of the double-effect heat pump unit is pressurized by the heat source water pump and comes to the upper section of the primary cooler again to exchange heat with the coke oven gas and enter the next cycle. S3. The low-temperature water produced by the refrigeration unit and the double-effect heat pump unit is incorporated into the low-temperature water network, and the hot water produced by the double-effect heat pump unit is incorporated into the hot water network.

[0012] The beneficial effects of the present invention are: 1. The technology of using residual ammonia water as heat source to produce low-temperature water after heat exchange with coke oven gas and the double-effect heat pump technology of using heat source water after indirect heat exchange between the double-effect heat pump unit and the upper gas of the primary cooler as the heat source has improved the utilization efficiency of coke oven gas waste heat and is beneficial to gas purification and deep processing.

[0013] 2. The problem of cooling the coke oven gas is solved by using refrigeration units and double-effect heat pump units to produce low-temperature water of 16°C and high-temperature water with an outlet temperature of about 110°C from the residual ammonia water exchanged with the coke oven gas and the heat source water exchanged with the coke oven gas in the upper section of the primary cooler. Low-temperature water (when cooling) and hot water (when heating) are produced by refrigeration units and double-effect heat pump units. The low-temperature water and hot water production modes are switched and adjusted according to production needs, which reduces the consumption of process circulating water required to cool the coke oven gas, improves the yield of chemical products, provides energy (heat source) for the production of low-temperature water and hot water, and makes new breakthroughs in low-carbon and carbon reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention discloses a process flow chart of a waste heat utilization system of coke oven gas.

[0015] The following are the descriptions of the reference numerals: 1. Circulating ammonia water pump; 2. Refrigeration unit; 3. Bridge pipe; 4. Riser; 5. Gas collecting pipe; 6. Gas-liquid separator; 7. Circulating ammonia water static oil removal device; 8. Primary cooler; 9. Heat source water pump; 10. Double-effect heat pump unit; 11. Pipeline; 12. Low-temperature water network; 13. Hot water network; 14. Heat source water return pipeline. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings: like Figure 1 As shown, a waste heat utilization system of coke oven gas includes a circulating ammonia water pump 1, one side of the circulating ammonia water pump 1 is connected to a refrigeration unit 2, the refrigeration unit 2 is connected to a bridge pipe 3 and a riser 4 through a pipeline 11, one side of the bridge pipe is connected to a gas collecting pipe 5, the gas collecting pipe 5 is connected to a gas-liquid separator 6, one side of the gas-liquid separator 6 is connected to a circulating ammonia water static oil removal device 7, the other side of the circulating ammonia water pump 1 is connected to the circulating ammonia water static oil removal device 7, the other side of the gas-liquid separator 6 is connected to a primary cooler 8, the primary cooler 8 is connected to a heat source water pump 9 and a double-effect heat pump unit 10 through a pipeline 11, the primary cooler 8 is connected to the double-effect heat pump unit 10 through a heat source water return pipeline 14, the refrigeration unit 2 and the double-effect heat pump unit 10 are connected to a low-temperature water network 12 through a pipeline 11, and the double-effect heat pump unit 10 is connected to a hot water network 13.

[0017] In this embodiment, two groups of refrigeration units 2 are provided, and the heat source inlet end of the refrigeration unit 2 is connected to the outlet end of the circulating ammonia water pump 1 through a pipeline 11, and the heat source outlet end of the refrigeration unit 2 is connected to the inlet end of the bridge pipe 3 and the outlet end of the riser 4 through a pipeline 11.

[0018] In this embodiment, the inlet end of the gas collecting pipe 5 is connected to the outlet end of the bridge pipe 3 through the pipeline 11 , and the outlet end of the gas collecting pipe 5 is connected to the inlet end of the gas-liquid separator 6 through the pipeline 11 .

[0019] In this embodiment, the liquid phase outlet end of the gas-liquid separator 6 is connected to the inlet end of the circulating ammonia static oil removal device 7 through a pipeline 11, and the gas phase outlet end of the gas-liquid separator 6 is connected to the coke oven gas inlet end of the primary cooler 8 through a pipeline 11.

[0020] In this embodiment, the circulating ammonia water outlet end of the circulating ammonia water static oil removal device 7 is connected to the inlet end of the circulating ammonia water pump 1 through a pipeline 11 .

[0021] In this embodiment, the inlet end of the water jacket of the upper section of the pre-cooler 8 is connected to the outlet end of the heat source water pump 9 through a pipe 11, the inlet end of the heat source water pump 9 is connected to the heat source outlet end of the double-effect heat pump unit 10 through a pipe 11, and the outlet end of the water jacket of the upper section of the pre-cooler 8 is connected to the heat source inlet end of the double-effect heat pump unit 10 through a heat source water return pipe 14.

[0022] In this embodiment, the cold water outlet end of the refrigeration unit 2 and the cold water outlet end of the double-effect heat pump unit 10 are connected to the low-temperature water network 12 through a pipe 11, and the hot water outlet end of the double-effect heat pump unit 10 is connected to the hot water network 13 through a pipe 11.

[0023] The waste heat utilization method of the present invention comprises the following steps: S1, the coke oven gas entering from the riser 4 is mixed with the sprayed circulating ammonia water at the bridge pipe 3 and then enters the gas collecting pipe 5, the coke oven gas and the circulating ammonia water are separated by the gas-liquid separator 6, the separated circulating ammonia water is deoiled by the circulating ammonia water static deoiling device 7, and after deoiling, it is pressurized by the circulating ammonia water pump 1 as a heat source to enter the refrigeration unit 2 for heat exchange to produce low-temperature water, and the circulating ammonia water coming out of the refrigeration unit 2 is mixed with the coke oven gas entering from the riser 4 at the bridge pipe 3 again to enter the next cycle; S2, the coke oven gas with a temperature of 80°C after separation at the gas-liquid separator 6 exchanges heat with the heat source water jacket of the double-effect heat pump unit 10 in the upper section of the primary cooler 8, and the heat source water of 78°C after absorbing heat enters the double-effect heat pump unit 10 to provide heat source, and the double-effect heat pump unit 10 produces 16°C low-temperature water in the cooling mode or 110°C hot water in the heating mode. The heat source water coming out of the double-effect heat pump unit 10 is pressurized by the heat source water pump 9 and comes to the upper section of the primary cooler 8 again to exchange heat with the coke oven gas, and enters the next cycle; S3. The low-temperature water produced by the refrigeration unit 2 and the double-effect heat pump unit 10 is integrated into the low-temperature water pipe network 12, and the hot water produced by the double-effect heat pump unit 10 is integrated into the hot water pipe network 13.

[0024] This method not only allows the waste heat of the coal gas that originally needed to be absorbed by process circulating water and naturally cooled by a cooling tower (sometimes assisted by cooling fan blowing) to be absorbed by the heat source water, reducing the consumption of process circulating water required to cool the coke oven gas, but also provides energy for the production of low-temperature water and hot water, which is beneficial to the purification and deep processing of coal gas and improves the recovery efficiency of chemical products.

[0025] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A waste heat utilization system of coke oven gas, characterized in that: The invention comprises a circulating ammonia water pump (1), one side of the circulating ammonia water pump (1) is connected to a refrigeration unit (2), the refrigeration unit (2) is connected to a bridge pipe (3) and a riser (4) through a pipeline (11), one side of the bridge pipe is connected to a gas collecting pipe (5), the gas collecting pipe (5) is connected to a gas-liquid separator (6), one side of the gas-liquid separator (6) is connected to a circulating ammonia water static oil removal device (7), and the other side of the circulating ammonia water pump (1) is connected to the circulating ammonia water static oil removal device (7). The other side of the gas-liquid separator (6) is connected to a primary cooler (8), the primary cooler (8) is connected to a heat source water pump (9) and a double-effect heat pump unit (10) via a pipeline (11), the primary cooler (8) is connected to the double-effect heat pump unit (10) via a heat source water return pipeline (14), the refrigeration unit (2) and the double-effect heat pump unit (10) are connected to a low-temperature water network (12) via a pipeline (11), and the double-effect heat pump unit (10) is connected to a hot water network (13).

2. A coke oven gas waste heat utilization system according to claim 1, characterized in that: The refrigeration unit (2) is provided with two groups, the heat source inlet end of the refrigeration unit (2) is connected to the outlet end of the circulating ammonia water pump (1) through a pipeline (11), and the heat source outlet end of the refrigeration unit (2) is connected to the inlet end of the bridge pipe (3) and the outlet end of the riser (4) through a pipeline (11).

3. The waste heat utilization system of coke oven gas according to claim 1, characterized in that: The inlet end of the gas collecting pipe (5) is connected to the outlet end of the bridge pipe (3) through a pipeline (11), and the outlet end of the gas collecting pipe (5) is connected to the inlet end of the gas-liquid separator (6) through a pipeline (11).

4. A coke oven gas waste heat utilization system according to claim 1, characterized in that: The liquid phase outlet end of the gas-liquid separator (6) is connected to the inlet end of the circulating ammonia water static oil removal device (7) through a pipeline (11), and the gas phase outlet end of the gas-liquid separator (6) is connected to the coke oven gas inlet end of the primary cooler (8) through a pipeline (11).

5. The coke oven gas waste heat utilization system according to claim 1, characterized in that: The circulating ammonia water outlet end of the circulating ammonia water static oil removal device (7) is connected to the inlet end of the circulating ammonia water pump (1) through a pipeline (11).

6. A coke oven gas waste heat utilization system according to claim 1, characterized in that: The inlet end of the water jacket of the upper section of the pre-cooler (8) is connected to the outlet end of the heat source water pump (9) via a pipeline (11); the inlet end of the heat source water pump (9) is connected to the heat source outlet end of the double-effect heat pump unit (10) via a pipeline (11); the outlet end of the water jacket of the upper section of the pre-cooler (8) is connected to the heat source inlet end of the double-effect heat pump unit (10) via a heat source water return pipeline (14).

7. The coke oven gas waste heat utilization system according to claim 1, characterized in that: The cold water outlet end of the refrigeration unit (2) and the cold water outlet end of the double-effect heat pump unit (10) are connected to the low-temperature water network (12) via a pipe (11), and the hot water outlet end of the double-effect heat pump unit (10) is connected to the hot water network (13) via a pipe (11).

8. The method for utilizing waste heat of a waste heat utilization system of coke oven gas according to claim 1, characterized in that: The waste heat utilization method comprises the following steps: S1, the coke oven gas entering from the riser (4) is mixed with the sprayed circulating ammonia water at the bridge pipe (3) and then enters the gas collecting pipe (5), the coke oven gas and the circulating ammonia water are separated by the gas-liquid separator (6), the separated circulating ammonia water is deoiled by the circulating ammonia water static deoiling device (7), and after deoiling, it is pressurized by the circulating ammonia water pump (1) and enters the refrigeration unit (2) as a heat source for heat exchange to produce low-temperature water, and the circulating ammonia water coming out of the refrigeration unit (2) is mixed with the coke oven gas entering from the riser (4) again at the bridge pipe (3) and enters the next cycle; S2. The coke oven gas separated at the gas-liquid separator (6) with a temperature of 80°C exchanges heat with the heat source water jacket of the double-effect heat pump unit (10) in the upper section of the primary cooler (8). The heat source water at 78°C after absorbing heat enters the double-effect heat pump unit (10) to provide a heat source. The double-effect heat pump unit (10) produces low-temperature water of 16°C in the cooling mode or hot water of 110°C in the heating mode. The heat source water from the double-effect heat pump unit (10) is pressurized by the heat source water pump (9) and then enters the upper section of the primary cooler (8) again to exchange heat with the coke oven gas and enter the next cycle. S3. The low-temperature water produced by the refrigeration unit (2) and the double-effect heat pump unit (10) is incorporated into the low-temperature water pipe network (12), and the hot water produced by the double-effect heat pump unit (10) is incorporated into the hot water pipe network (13).

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