System for recovering pressure and heat and oxygen-rich gas from a PSA nitrogen generator

Abstract

The application provides a system for recycling the waste pressure and waste heat and oxygen-rich gas of a PSA nitrogen generator, which is characterized in that the exhaust outlet of at least one adsorption tower is connected with the inlet of an oxygen-rich air buffer tank, the outlet of the oxygen-rich air buffer tank is connected with an air turbine and a generator, and the exhaust outlet of the air turbine is connected with an oxygen-rich air storage tank. After the oxygen-rich gas recycled from the waste pressure and waste heat is used to generate electricity, more than 20% of the power input of the nitrogen generator set can be recycled, and after the oxygen-rich gas generated by the electricity generation is used to assist combustion of production equipment such as a boiler and a kiln, the total power input of the nitrogen generator set can reach 30%, and the economic benefits are considerable.

Description

TECHNICAL FIELD

[0001] The present application relates to a system for recycling the residual pressure and heat and oxygen-rich gas of a PSA nitrogen generator, and belongs to the technical field of thermal power and energy saving. BACKGROUND

[0002] The PSA nitrogen generator is one of the devices widely used for nitrogen production at present. However, in the actual production and application, there is a major defect of high energy consumption, mainly embodied in the following three aspects: first, when producing nitrogen, the air needs to be pressurized to above 0.6 MPa, and the temperature of the compressed air reaches above 200℃, and the physical heat of this part is basically not utilized; second, in the process of nitrogen production, the nitrogen adsorber discharges a large amount of oxygen-rich air with a pressure of above 0.6 MPa, and the residual pressure of this part is not recycled and utilized; third, in the process of nitrogen production, the discharged oxygen-rich gas has an oxygen content of 27-30%, and the oxygen of this part is not fully utilized. At present, the cost of electricity required for producing 1m³ of nitrogen with a content of 99.5% is 0.25 yuan / m³.

[0003] Therefore, developing a residual pressure, residual heat and oxygen-rich gas recycling system for utilizing the residual pressure, residual heat and oxygen-rich gas of a PSA nitrogen generator set, and using it for power generation and promoting boiler combustion to save energy has become one of the means for energy saving and consumption reduction. SUMMARY

[0004] The present application aims to provide a system for recycling the residual pressure, residual heat and oxygen-rich gas of a PSA nitrogen generator set, so as to use the recycled residual pressure and heat for power generation, and use the recycled oxygen-rich gas for assisting the combustion of a boiler, so as to realize power generation and promote the combustion of oxygen-rich air of a boiler while producing nitrogen, and finally reduce the energy consumption of the nitrogen generator, promote power production and energy saving and consumption reduction of the boiler.

[0005] The present application is realized through the following technical scheme: a system for recycling the residual pressure, residual heat and oxygen-rich gas of a PSA nitrogen generator set, which is connected in sequence with an air compressor connected to the inlet of at least one adsorption tower of the PSA nitrogen generator, a compressed air buffer tank, a refrigeration type dryer, and a nitrogen storage tank connected to the outlet of the at least one adsorption tower, characterized in that the exhaust outlet of the at least one adsorption tower is connected to the inlet of an oxygen-rich air buffer tank, the outlet of the oxygen-rich air buffer tank is connected to an air turbine and a generator, and the exhaust outlet of the air turbine is connected to an oxygen-rich air storage cabinet, so that after the air is compressed by the compressor, it enters the compressed air buffer tank, then enters the double nitrogen adsorption tower through the refrigeration type dryer, the generated nitrogen enters the nitrogen storage tank, the discharged oxygen-rich gas enters the oxygen-rich air buffer tank, and after driving the turbine impeller to rotate, the generator generates electricity, and after being controlled by a control cabinet and sent to a grid connection cabinet, it is used for external power supply, the exhaust gas of the turbine is sent to the oxygen-rich air storage cabinet, and then is sent to an oxygen-rich air user such as a boiler for combustion assistance, so as to realize the power generation of the oxygen-rich air of the PSA nitrogen generator and the recycling and reuse of the oxygen-rich gas after power generation.

[0006] The compression air buffer tank is provided with a heat absorption pipe, the oxygen-enriched air storage tank is provided with a heat release pipe, and the heat absorption pipe and the heat release pipe are communicated, so that the physical heat generated by air compression is absorbed by the heat absorption pipe and then transmitted to the heat release pipe in the oxygen-enriched air storage tank to heat the oxygen-enriched air in the oxygen-enriched air storage tank, thereby improving the power generation efficiency of the oxygen-enriched air and further improving the combustion-supporting efficiency of the oxygen-enriched air.

[0007] The exhaust gas outlet of the double adsorption tower is connected with the inlet of the oxygen-enriched air buffer tank through a pipeline provided with a control valve, and the control valve is connected with the instrument controller, so as to control the control valve through the instrument controller.

[0008] The exhaust gas outlet of the air turbine is connected with the oxygen-enriched air storage tank through a pipeline provided with a silencer and a check valve, so as to send the oxygen-enriched air to a boiler or the like for combustion support.

[0009] The oxygen-enriched air buffer tank is provided with one tank for collecting the oxygen-enriched air discharged by the double nitrogen gas adsorption tower, the design working pressure of the oxygen-enriched air buffer tank is at least 1 / 3 of that of one nitrogen gas adsorption tower, and the volume of the oxygen-enriched air buffer tank is at least times of that of one nitrogen gas adsorption tower.

[0010] The oxygen-enriched air buffer tank is provided with a temperature sensor, a safety diffusing valve at the top and a blowdown valve at the bottom, and the temperature sensor, the safety diffusing valve and the blowdown valve are connected with the instrument controller.

[0011] The compression air buffer tank is provided with a temperature sensor, a safety diffusing valve at the top and a blowdown valve at the bottom, and the temperature sensor, the safety diffusing valve and the blowdown valve are connected with the instrument controller.

[0012] The gas check valve is mainly used for ensuring that the oxygen-enriched gas is discharged at the design working pressure and preventing the oxygen-enriched gas from flowing back due to external factors.

[0013] The gas check valve comprises a valve body, an air inlet pipe, an air outlet pipe, a water supply pipe and a water seal height-adjustable overflow drain pipe, wherein the valve body is filled with production water, the air inlet pipe is inserted into the water to form a water seal, and when the working pressure in the air inlet pipe reaches the design value, the gas breaks through the water seal and enters the air outlet pipe to be sent out; the water seal height-adjustable overflow drain pipe adjusts the water seal height through an expansion joint.

[0014] The electricity generated by the generator is connected with the control cabinet and the grid-connected cabinet through a cable to supply electricity to the outside.

[0015] The control valves, instruments and instruments in the system are connected with the instrument controller through wires, so as to supervise and control the control valves, instruments and instruments through the instrument controller.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] (1) the present application solves the problem that the physical sensible heat of compressed air of common nitrogen making machine is not recycled, the sensible heat of compressed air is recycled through the heat absorption pipe arranged in the compressed air buffer tank, and then is sent to the heat release pipe arranged in the oxygen-rich air storage tank 15.

[0018] (2) the present application utilizes the oxygen-rich gas residual pressure generated by the common nitrogen making machine, heats the oxygen-rich air, and then sends the oxygen-rich air to the turbine generator set to generate power efficiently, thereby saving energy effectively.

[0019] (3) the oxygen-rich gas after power generation is recycled, and is used for combustion support of boilers, kilns and other production equipment, thereby fully utilizing the oxygen-rich gas and reducing energy consumption.

[0020] More than 20% of the power input of the nitrogen making machine can be recycled, and after the boiler combustion is promoted by using the oxygen-rich air, the total power input of the nitrogen making unit can be recycled by 30%. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0022] Figure 1 Configuration diagram of the system of the present application;

[0023] Figure 2 Schematic diagram of the oxygen-rich air buffer tank of the present application;

[0024] Figure 3 Schematic diagram of the compressed air buffer tank of the present application;

[0025] Figure 4 Schematic diagram of the gas check valve of the present application. DETAILED DESCRIPTION

[0026] The present application will be further described in detail below in combination with the embodiments.

[0027] Those skilled in the art will understand that the following embodiments are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. If the specific technology or condition is not indicated in the embodiments, the technology or condition described in the literature in the art or according to the product instruction is used. If the manufacturer of the material or equipment is not indicated, it is a conventional product that can be obtained by purchase.

[0028] The following examples are intended to illustrate but not limit the present application. Unless otherwise indicated, technical, connection relations, or conditions in the examples are carried out according to the techniques, connection relations, or conditions described in the literature in the art or according to the product instructions. Unless otherwise indicated, the materials, instruments, or equipment used are conventional products that can be obtained by purchase.

[0029] It will be understood by those within the art that, in this disclosure, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It will be understood that when an element is referred to as being "connected" to or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements can be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0030] In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more. The orientation or positional relationship indicated by the terms "inner", "upper", "lower", and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0031] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "provided with" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application should be understood according to the specific circumstances.

[0032] It will be understood by those within the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0033] As Figures 1-4As shown, the system for recovering the pressure and heat and oxygen-rich gas of the PSA nitrogen generator provided by the application comprises: an air compressor 1, a compressed air buffer tank 2, a refrigeration dryer 3 connected with the inlet of a double adsorption tower 6 of the PSA nitrogen generator in sequence, and a nitrogen storage tank 7 connected with the outlet of the double adsorption tower 6, characterized in that the exhaust outlet of the double adsorption tower 6 is connected with the inlet of an oxygen-rich air buffer tank 15, the outlet of the oxygen-rich air buffer tank 15 is connected with an air turbine 14, a generator 13, a control cabinet 12 and a grid-connected cabinet 11, and the exhaust outlet of the air turbine 14 is connected with an oxygen-rich air storage tank 9, so that after the air is compressed by the compressor 1, the air enters the compressed air buffer tank 2, then enters the double nitrogen adsorption tower 6 through the refrigeration dryer 3, the generated nitrogen enters the nitrogen storage tank 7, the discharged 0.6 MPa oxygen-rich gas enters the oxygen-rich air buffer tank 15, the turbine 14 impeller rotates to drive the generator 13 to generate electricity, and after the control of the control cabinet 12, the electricity is sent to the grid-connected cabinet 11 and then supplied to external users, the exhaust gas of the turbine 14 is sent to the oxygen-rich air storage tank 9 and then to the oxygen-rich air users such as boilers for combustion support, so as to realize the oxygen-rich air power generation of the PSA nitrogen generator and the recycling of the oxygen-rich gas after power generation.

[0034] The compressed air buffer tank 2 is provided with a heat absorption pipe 17, the oxygen-rich air storage tank 15 is provided with a heat release pipe 16, and the heat absorption pipe 17 and the heat release pipe 16 are communicated, so that the physical heat generated by air compression is absorbed by the heat absorption pipe 17 and then transmitted to the heat release pipe 16 in the oxygen-rich air storage tank 15 to heat the oxygen-rich air in the oxygen-rich air storage tank 15, thereby improving the power generation efficiency of the oxygen-rich air and further improving the combustion support efficiency of the oxygen-rich air.

[0035] The exhaust outlet of the double adsorption tower 6 is connected with the inlet of the oxygen-rich air buffer tank 15 through a pipeline provided with a control valve 5, and the control valve 5 is connected with an instrument control device 4, so as to control the control valve 5 through the instrument control device 4.

[0036] The exhaust outlet of the air turbine 14 is connected with the oxygen-rich air storage tank 9 through a pipeline provided with a silencer 8 and a check valve 10, so as to send the oxygen-rich air to the boilers for combustion support.

[0037] One oxygen-rich air buffer tank 15 is arranged to collect the oxygen-rich air discharged by the double nitrogen adsorption tower 6, the design working pressure of the oxygen-rich air buffer tank 15 is 1 / 3 of that of the double nitrogen adsorption tower 6, and the volume of the oxygen-rich air buffer tank 15 is 3 times the volume of a single nitrogen adsorption tower 6.

[0038] The oxygen-rich air buffer tank 15 is provided with a temperature sensor 18, a safety relief valve 19 at the top and a blowdown valve 20 at the bottom, and the temperature sensor 18, the safety relief valve 19 and the blowdown valve 20 are connected with the instrument control device 4.

[0039] The compressed air buffer tank 2 is provided with a temperature sensor 23, a safety relief valve 21 at the top and a blowdown valve 22 at the bottom, and the temperature sensor 23, the safety relief valve 21 and the blowdown valve 22 are connected with the instrument controller 4.

[0040] The gas check valve 10 is mainly used to ensure that the oxygen-enriched gas is discharged at the designed working pressure and prevent the oxygen-enriched gas from backflowing due to external factors.

[0041] The gas check valve 10 comprises a valve body 24, an air inlet pipe 25, an air outlet pipe 27, a water supply pipe 26 and a water seal height-adjustable overflow drain pipe 28; the valve body 24 is internally filled with production water, the air inlet pipe 25 is inserted into the water to form a water seal, and after the working pressure in the air inlet pipe 25 reaches the designed value, the gas breaks through the water seal to enter the air outlet pipe 27 for external delivery; the water seal height-adjustable overflow drain pipe 28 adjusts the water seal height through an expansion joint 29.

[0042] The control valves, instruments and apparatus in the system are connected with the instrument controller 4 through wires so as to be supervised and controlled by the instrument controller 4.

[0043] Application example

[0044] Taking a 2500m³ / h PSA nitrogen generator as an example, a waste heat and oxygen-enriched gas recovery system is configured with two air compressors with a motor power of 560kW, Q=96.5m³ / min and an exhaust pressure of 0.8MPa to provide a gas source; two compressed air buffer tanks with a capacity of 50m³ and P=0.8MPa are arranged, and the compressed air stays for 248s to enable the heat absorption pipe to fully absorb the sensible heat of the compressed air; the refrigeration type dryer, the nitrogen adsorption tower and the nitrogen storage tank are configured according to the prior art; two electric valves are arranged for the oxygen-enriched discharge device, one is an oxygen-enriched air buffer tank inlet valve, and the other is an oxygen-enriched air discharge end emptying valve; a 100m³ oxygen-enriched air storage tank with P=0.2MPa is arranged to provide a power gas source for the turbine generator set; a 250kW turbine generator set, a supporting control cabinet and a grid-connected cabinet are arranged; a pipeline silencer with Q=10000m³ / h and a gas check valve with Q=10000m³ / h are arranged for oxygen-enriched gas recovery.

[0045] After the implementation, more than 20% of the power input of the nitrogen generator can be recovered, and after the oxygen-enriched air is used to promote the combustion of the boiler, the total power input of the nitrogen generator set can be recovered by 30%, and the economic benefits are very considerable.

Claims

1. A system for recovering residual pressure, waste heat, and oxygen-enriched gas from a PSA nitrogen generator, comprising an air compressor, a compressed air buffer tank, a refrigerated dryer, and a nitrogen storage tank connected sequentially to the inlet of at least one adsorption tower of the PSA nitrogen generator, and connected to the outlet of at least one adsorption tower, characterized in that... The exhaust gas outlet of the at least one adsorption tower is connected with the inlet of the oxygen-enriched air buffer tank, the outlet of the oxygen-enriched air buffer tank is connected with the air turbine and the generator, and the exhaust gas outlet of the air turbine is connected with the oxygen-enriched air storage tank. The heat absorption pipe is arranged in the compressed air buffer tank, the heat release pipe is arranged in the oxygen-enriched air storage tank, and the heat absorption pipe and the heat release pipe are communicated. The exhaust gas outlet of the air turbine is connected with the oxygen-enriched air storage tank through a pipeline provided with a silencer and a check valve.

2. The system for recovering pressure and heat and oxygen enriched gas from a PSA nitrogen generator of claim 1, wherein The at least one adsorption tower is a double adsorption tower, the exhaust gas outlet of the double adsorption tower is connected with the inlet of the oxygen-enriched air buffer tank through a pipeline provided with a control valve, and the control valve is connected with the instrument controller.

3. The system for recovering pressure and heat and oxygen enriched gas from a PSA nitrogen generator of claim 1, wherein The oxygen-enriched air buffer tank is provided with a temperature sensor, a safety relief valve at the top and a blowdown valve at the bottom, and the temperature sensor, the safety relief valve and the blowdown valve are connected with the instrument controller.

4. The system for recovering pressure and heat and oxygen enriched gas from a PSA nitrogen generator of claim 1, wherein The compressed air buffer tank is provided with a temperature sensor, a safety relief valve at the top and a blowdown valve at the bottom, and the temperature sensor, the safety relief valve and the blowdown valve are connected with the instrument controller.

5. The system for recovering pressure and heat and oxygen enriched gas from a PSA nitrogen generator of claim 1, wherein The gas check valve comprises a valve body, an air inlet pipe, an air outlet pipe, a water supply pipe and a water seal height-adjustable overflow drain pipe.

6. The system for recovering pressure and heat and oxygen enriched gas from a PSA nitrogen generator of claim 1, wherein The electricity generated by the generator is connected with the control cabinet and the grid-connected cabinet through a cable.

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