CN206543508U - It is a kind of using liquid nitrogen as low-temperature receiver and the vehicular VOCs condensate recovery systems of nitrogen source - Google Patents

Abstract

A vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and a nitrogen source relates to the field of purification and adsorption of VOC gases. The system consists of a scavenging gas circuit, a temperature rise desorption circuit and a condensation recovery circuit. When the VOCs adsorption device is saturated, the vehicle-mounted VOCs condensation recovery system is connected to the VOCs adsorption device. The system is in the scavenging gas circuit, and the system is evaporated by liquid nitrogen. The internal oxygen is evacuated to the set limit to prevent the combustion and explosion of organic matter during the heating and desorption process; the system is switched to the heating and desorption circuit, and the organic waste gas contained in the saturated adsorbent in the adsorption device is blown off and separated through the air heater; the system is switched to Condensation recovery circuit, the gaseous organic matter blown off is heat-exchanged with liquid nitrogen to realize condensed liquefaction collection. The system can eventually recover VOCs into the vehicle system and transport them for centralized treatment, while enabling the saturated adsorption device to be regenerated in situ. It has the advantages of simple structure, convenient operation, high VOCs treatment efficiency, low operating cost and low energy consumption.

Description

A vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and nitrogen source

technical field

The utility model relates to the field of purification and adsorption of VOC gas, in particular to a vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and a nitrogen source.

Background technique

Volatile industrial organic waste gases (VOCs) are an important part of air pollution. They not only directly endanger human health, but also are the main precursors of other air pollution sources such as PM2.5 and ozone. At present, the treatment methods for VOCs gas include biological treatment, regenerative combustion, plasma catalysis, photocatalysis, etc. However, in actual engineering, the above-mentioned technologies are often limited by investment costs, operating costs, and site conditions, making it difficult to be widely used. In contrast, the removal of VOCs gas by physical adsorption has the characteristics of high efficiency, simple process, low initial investment cost, and easy operation and maintenance. However, when physical adsorption is used for the removal of organic waste gas, the adsorbent will soon reach saturation, and then lose the ability to remove VOCs gas. At this time, industrial enterprises can only choose to replace the adsorbent or perform in-situ desorption and regeneration on it. If the adsorbent is replaced, the saturated adsorbent needs to be handed over to a qualified unit for solid waste treatment; if the adsorbent is regenerated in situ, the enterprise will also invest in the construction of the regeneration system, so although the initial investment cost of physical adsorption technology is low , but the follow-up operating costs still lead to an increase in the environmental governance costs of industrial enterprises.

Contents of the invention

Aiming at the shortcomings of the existing technology, the utility model proposes a vehicle-mounted VOCs condensation recovery system with liquid nitrogen as the cold source and nitrogen source, which has a reasonable design, can realize adsorption regeneration, and has the advantages of low cost, safety and reliability.

In order to solve the above-mentioned technical problems, the technical solution adopted by the utility model is: a vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and a nitrogen source. , the first thermocouple, the first three-way valve, the circulating centrifugal fan, the pipeline heater, the second thermocouple, the second three-way valve, the air cooler, the third thermocouple, the liquid nitrogen condenser and the third three-way valve , the gas output end of the liquid nitrogen storage tank is installed in sequence with the first on-off valve, the first thermocouple, the first three-way valve, the circulating centrifugal fan, the pipeline heater, the second thermocouple, the second three-way valve, and the air condensation After the pipes of the third thermocouple, liquid nitrogen condenser, and the third three-way valve are connected, they are divided into two paths. One path is connected back to the liquid nitrogen storage tank, and the other path is connected to the outside atmosphere. Between the pipe heater and the second thermocouple VOCs adsorption device is connected between them.

In the case where the first input end of the first three-way valve communicates with the output end, the input end of the second three-way valve communicates with the second output end, and the input end of the third three-way valve communicates with the second output end:

An auxiliary electric heater is arranged in the liquid nitrogen storage tank, a first thermocouple is installed on the connecting pipe between the first input end of the first three-way valve and the first switching valve, and the output end of the first three-way valve is connected to the first switch valve. The pipeline connection of circulating centrifugal fan, pipeline heater, second thermocouple and second three-way valve is installed in sequence; the input end of the second three-way valve is connected with the second thermocouple, and the second output end of the second three-way valve is connected with A pipeline connection with an air cooler, a third thermocouple, a liquid nitrogen condenser and a third three-way valve is installed in sequence; a liquid nitrogen condenser is installed on the pipeline connected to the input end of the third three-way valve, which is connected with the third three-way valve. The second output end of the through valve passes through the pipeline installed with the activated carbon tank for absorbing VOCs gas, and then connects with the external atmospheric end to form a scavenging gas path, and the nitrogen gas generated by the auxiliary electric heater passes through the gas outlet of the liquid nitrogen storage tank Entering into the scavenging gas circuit, the oxygen in the pipeline is purged and emptied, and discharged into the atmosphere through the outlet of the activated carbon tank.

The pipeline connected to the output end of the activated carbon tank is provided with an oxygen sensor for detecting the concentration of exhausted oxygen after being adsorbed by the activated carbon tank and a VOCs sensor for detecting the concentration of exhausted VOCs gas.

In the case where the output port of the first three-way valve communicates with the second input port, and the input port of the second three-way valve communicates with the first output port:

After the output end of the first three-way valve is connected to the pipeline installed with the circulating centrifugal fan, the pipeline heater, the second thermocouple and the second three-way valve in sequence, the first output end of the second three-way valve is connected to the first three-way valve. The pipeline between the second input ends of the valve is connected to form a temperature-rising desorption loop, and the gas in the pipeline is heated by the pipeline heater, so that the VOCs gas in the VOCs adsorption device can achieve temperature-rising thermal desorption.

In the case where the first input end of the first three-way valve is connected to the output end, the input end of the second three-way valve is connected to the second output end, and the input end of the third three-way valve is connected to the first output end:

The first input end of the first three-way valve is connected to the pipeline equipped with the first thermocouple, and the output end of the first three-way valve is connected with the circulating centrifugal fan, the pipeline heater, and the second thermocouple installed in sequence, for After VOCs high-temperature nitrogen is used for primary cooling, the air cooler, the third thermocouple, and the pipeline of the liquid nitrogen condenser are connected, and after passing through the input end and the first output end of the third three-way valve, the fourth thermocouple, The pipeline connection of the fourth on-off valve is connected with the gas input end of the liquid nitrogen storage tank; the pipeline between the liquid output end of the liquid nitrogen storage tank and the liquid nitrogen condenser is also connected in turn for extracting nitrogen liquid for secondary Level cooling liquid nitrogen circulation pump and second switching valve.

A pressure gauge is connected to the gas output end of the liquid nitrogen storage tank.

A VOCs sensor is also installed on the pipeline between the second output end of the second three-way valve and the air cooler.

A gas flow agent is also installed on the pipeline between the output end of the first three-way valve and the circulating fan.

The VOCs adsorption device is connected between the circulating centrifugal fan and the second thermocouple through a stainless steel hose.

A third on-off valve is installed on the pipeline connected to the output end of the liquid nitrogen condenser.

Beneficial effects of the utility model: the vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and nitrogen source uses a VOCs adsorption device to adsorb and purify organic pollutants in industrial waste gas, so that enterprises can meet relevant emission standards. When the VOCs adsorption device is saturated, the vehicle-mounted VOCs condensation recovery system is connected to the VOCs adsorption device, and the system is switched to the scavenging gas circuit, and the oxygen in the system is evacuated to the set limit through the evaporation of liquid nitrogen to prevent the temperature rise during the desorption process. The organic matter burns and explodes; then the system switches to the temperature rise desorption circuit, and the organic waste gas contained in the saturated adsorbent in the adsorption device is blown off and separated through the air heater; finally the system is switched to the condensation recovery circuit, and the gaseous organic matter and liquid nitrogen blown off are separated Heat exchange to realize condensate liquefaction collection. The system can eventually recover VOCs into the vehicle system and transport them for centralized treatment, while enabling the saturated adsorption device to be regenerated in situ. The system is simple in structure and easy to operate. It has the characteristics of high VOCs treatment efficiency, low operating cost, and low energy consumption, which can greatly reduce the cost of VOCs governance for enterprises.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only the present invention. For some embodiments of the present invention, those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the overall structural block diagram of the vehicle-mounted VOCs condensation recovery system with liquid nitrogen as cold source and nitrogen source in the embodiment of the utility model;

The serial numbers in the figure are as follows: 1 liquid nitrogen storage tank, 2 auxiliary electric heater, 3 pressure gauge, 4 on-off valve, 5 thermocouple, 6 three-way valve, 7 gas flow meter, 8 circulating centrifugal fan, 9 pipeline heater, 10 VOCs adsorption device, 11 thermocouple, 12 three-way valve, 13 VOCs sensor, 14 air cooler, 15 thermocouple, 16 liquid nitrogen condenser, 17 on-off valve, 18 liquid nitrogen circulation pump, 19 on-off valve, 20 three-way valve, 21 Activated carbon tank, 22 Oxygen sensor, 23 VOCs sensor, 24 Thermocouple, 25 On-off valve.

detailed description

In order to make the above purpose, features and advantages of the utility model more obvious and easy to understand, the utility model will be further described in detail below in conjunction with the accompanying drawing 1 and specific embodiments.

Example 1:

The vehicle-mounted VOCs condensation recovery system using liquid nitrogen as the cold source and nitrogen source used in this embodiment is shown in Figure 1. The system is connected with the VOCs adsorption device, which constitutes the scavenging gas circuit, the temperature rise desorption circuit and the condensation recovery circuit respectively. In this embodiment, the switch of the pipeline is realized by controlling the opening and closing of each valve installed on the pipeline, so that the system is in different working modes. Its basic circuit includes liquid nitrogen storage tank 1, switch valve 4 set on the pipeline, thermocouple 5, three-way valve 6, circulating centrifugal fan 8, pipeline heater 9, thermocouple 11, three-way valve 12, air cooler 14. Thermocouple 15, liquid nitrogen condenser 16 and three-way valve 20, the gas output end of liquid nitrogen storage tank 1 is provided with switch valve 4, thermocouple 5, three-way valve 6, circulating centrifugal fan 8, pipeline heater 9. The pipelines of thermocouple 11, three-way valve 12, air cooler 14, thermocouple 15, liquid nitrogen condenser 16 and three-way valve 20 are connected, one output end of the pipeline is connected to the outside atmosphere, and the other output end is connected to liquid nitrogen Tank 1. A VOCs adsorption device 10 is connected between the pipe heater 9 and the thermocouple 11 .

Example 2:

The difference between embodiment 2 and embodiment 1 is that when the 6a end of the three-way valve 6 arranged in the pipeline communicates with the 6c end and 6b closes, the 12a port of the three-way valve 12 communicates with the 12c port and 12b closes, and the three-way valve When the 20a end of 20 is connected to the 20c end and 20b is closed, the auxiliary electric heater 2 is turned on, the pipe heater 9 is turned off, and the air cooler 14 is turned off, the scavenging air path is formed, as follows:

Install the auxiliary electric heater 2 in the liquid nitrogen storage tank 1, connect the thermocouple 5 on the pipeline between the on-off valve 4 and the 6a end of the three-way valve 6, and install them sequentially on the pipeline communicating with the 6c end of the three-way valve 6 There are a gas flow meter 7, a circulating centrifugal fan 8, a pipeline heater 9 and a thermocouple 11, and the VOCs adsorption device 10 is connected to the pipeline heater 9 and the thermocouple 11 through a stainless steel hose. The thermocouple 11 is provided on a pipe communicating with the end 12 a of the three-way valve 12 . A VOCs sensor 13 , an air cooler 14 , a thermocouple 15 and a liquid nitrogen condenser 16 are sequentially connected to the pipeline communicating with the end 12c of the three-way valve 12 . An activated carbon canister 21 for adsorbing VOCs gas is installed on the pipeline communicating with the 20c end of the three-way valve 20, and the pipeline communicates with the atmosphere to form a scavenging gas path. The nitrogen gas produced by heating the liquid nitrogen by the auxiliary electric heater 2 enters the above-mentioned exhaust gas path through the gas outlet of the liquid nitrogen storage tank 1, so that the oxygen in the pipeline is purged and emptied, and is discharged into the atmosphere through the outlet of the activated carbon tank 21. The output end of the activated carbon canister 21 is provided with an oxygen sensor 22 for detecting the exhausted oxygen concentration after being adsorbed by the activated carbon canister and a VOCs sensor 23 for detecting the exhausted VOCs gas concentration. The main purpose of this process is to purge and empty the oxygen in the gas path, and at the same time use the activated carbon canister 21 to adsorb the purged VOCs to avoid secondary pollution. When the oxygen content measured by the oxygen sensor 22 is lower than the set value, the vehicle-mounted condensation recovery system completes the scavenging work and enters the temperature-rising desorption mode.

When the 6b port of the three-way valve 6 on the pipeline is communicated with the 6c port and the 6a end is closed, the 12a port of the three-way valve 12 is communicated with the 12b port and the 12c end is closed, and the 20a end of the three-way valve 20 is communicated with the 20c end and When the terminal 20b is closed, the auxiliary electric heater 2 is closed, the pipeline heater 9 is opened, the air cooler 14 is closed, the on-off valve 19 is closed, and the on-off valve 17 is closed, a heating and desorption circuit is formed. The specific structure is as follows:

A circulating centrifugal fan 8, a pipeline heater 9, a VOCs adsorption device, an electric thermocouple 11 and a three-way valve 12 are sequentially arranged on the pipeline connected to the 6c end of the three-way valve 6, and on the pipeline connected to the 12a end of the three-way valve 12 Connected with a thermocouple 11, the pipeline between the 12b end of the three-way valve 12 and the 6b end of the three-way valve 6 is connected to form a temperature rise desorption loop, and the gas in the pipeline is heated by the pipeline heater 9 to make the VOCs adsorption device VOCs gas realizes thermal desorption by heating up. When the vehicle-mounted condensation recovery system is in the temperature-rising desorption mode, nitrogen is heated in a sealed cycle in the temperature-rising desorption circuit, thereby reducing the amount of nitrogen used. When the nitrogen temperature is raised and maintained at the set temperature, thermal desorption of VOCs in the adsorption device can be realized. After the process runs for a period of time, the vehicle-mounted condensation recovery system completes the temperature rise and desorption work and enters the condensation recovery mode.

When the 6a end of the three-way valve 6 in the pipeline is communicated with the 6c end and the 6b end is closed, the 12a port of the three-way valve 12 is communicated with the 12c port and the 12b end is closed, and the 20a end of the three-way valve 20 is communicated with the 20b end and Terminal 20c is closed, the auxiliary electric heater 2 is closed, the circulating centrifugal fan 8 is opened, the pipeline heater 9 is closed, the air cooler 14 is opened, the on-off valve 17 is opened, the nitrogen liquid circulation pump 18 is started, the on-off valve 19 is closed, and the on-off valve 25 is started In the case of a condensate recovery loop, the specific structure is as follows:

A pressure gauge 3 is connected to the gas output end of the liquid nitrogen storage tank 1 . A switch valve 4, a thermocouple 5, and a three-way valve 6 are sequentially arranged on the pipeline connected to the gas output end of the liquid nitrogen storage tank 1, and a gas flow meter 7, a circulation valve, and a gas flow meter 7 are connected to the pipeline connected to the 6c end of the three-way valve 6 in sequence. A centrifugal fan 8, a pipe heater 9, a thermocouple 11 and a three-way valve 12, wherein the VOCs adsorption device 10 is connected between the pipe heater 9 and the thermocouple 11 through a stainless steel hose.

The pipeline connected with the 12a end of the three-way valve 12 is connected with a thermocouple 11, and the pipeline connected with the 12c end of the three-way valve 12 is connected with a VOCs sensor 13, an air condenser 14, a thermocouple 15, and a liquid nitrogen condenser 16 in sequence. And the three-way valve 20, the pipeline between the 20b end of the three-way valve 20 and the gas input end of the liquid nitrogen storage tank 1 is connected in sequence by a thermocouple 24 and a switching valve 25. A liquid nitrogen circulation pump 18 and a switching valve 17 are sequentially connected to the pipeline between the liquid output end of the liquid nitrogen storage tank 1 and the liquid nitrogen condenser 16 .

The high-temperature nitrogen gas containing VOCs generated during the temperature-rising desorption process is firstly cooled by the air cooler 14 . The liquid nitrogen in the liquid nitrogen storage tank 1 is pumped into the liquid nitrogen condenser 16 by the liquid nitrogen circulation pump 18 through the switch valve 17, and the gas discharged from the air cooler 14 undergoes secondary deep condensation and then returns to the liquid nitrogen storage tank 1. . After the two-stage condensation, the VOCs in the desorbed nitrogen gas can be completely cooled and liquefied when the temperature rises, and the liquid accumulates in the liquid nitrogen condenser 16 . The nitrogen gas after condensing and removing VOCs returns to the liquid nitrogen storage tank 1 through the three-way valve 20, thermocouple 24, and on-off valve 25, and then is driven by the centrifugal fan 8 to be recycled in the condensation recovery circuit. When the concentration indication of the VOCs sensor 13 reaches the set requirement, the system work is completed, and the on-off valve 19 is opened to collect the liquid-phase VOCs.

The above is only a specific embodiment of the present utility model, but the scope of protection of the present utility model is not limited thereto. Anyone familiar with the technical field can easily think of changes or changes within the technical scope disclosed by the utility model Replacement should be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (10)

1. A vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and a nitrogen source, characterized in that it includes a liquid nitrogen storage tank, a first switch valve, a first thermocouple, a first three-way valve, and a circulating centrifugal fan , pipeline heater, second thermocouple, second three-way valve, air cooler, third thermocouple, liquid nitrogen condenser and third three-way valve, the gas output end of the liquid nitrogen storage tank is installed with the first On-off valve, first thermocouple, first three-way valve, circulating centrifugal fan, pipe heater, second thermocouple, second three-way valve, air condenser, third thermocouple, liquid nitrogen condenser, third three After the pipeline of the through valve is connected, it is divided into two paths, one pipeline is connected back to the liquid nitrogen storage tank, the other pipeline is connected to the outside atmosphere, and the VOCs adsorption device is connected between the pipeline heater and the second thermocouple. 2. The vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and nitrogen source as claimed in claim 1, characterized in that, In the case where the first input end of the first three-way valve communicates with the output end, the input end of the second three-way valve communicates with the second output end, and the input end of the third three-way valve communicates with the second output end: An auxiliary electric heater is arranged in the liquid nitrogen storage tank, a first thermocouple is installed on the connecting pipe between the first input end of the first three-way valve and the first switching valve, and the output end of the first three-way valve is connected to the first switch valve. The pipeline connection of circulating centrifugal fan, pipeline heater, second thermocouple and second three-way valve is installed in sequence; the input end of the second three-way valve is connected with the second thermocouple, and the second output end of the second three-way valve is connected with A pipeline connection with an air cooler, a third thermocouple, a liquid nitrogen condenser and a third three-way valve is installed in sequence; a liquid nitrogen condenser is installed on the pipeline connected to the input end of the third three-way valve, which is connected with the third three-way valve. The second output end of the through valve passes through the pipeline installed with the activated carbon tank for absorbing VOCs gas, and then connects with the external atmospheric end to form a scavenging gas path, and the nitrogen gas generated by the auxiliary electric heater passes through the gas outlet of the liquid nitrogen storage tank Entering into the scavenging gas circuit, the oxygen in the pipeline is purged and emptied, and discharged into the atmosphere through the outlet of the activated carbon tank. 3. The vehicle-mounted VOCs condensation recovery system with liquid nitrogen as cold source and nitrogen source as claimed in claim 2, characterized in that, the pipeline connected to the output end of the activated carbon tank is provided with a device for detecting Oxygen sensor for exhaust oxygen concentration after adsorption and VOCs sensor for exhaust VOCs gas concentration. 4. The vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and a nitrogen source as claimed in claim 1, wherein the output end of the first three-way valve communicates with the second input end, and the second three-way valve Where the input port of the valve communicates with the first output port: After the output end of the first three-way valve is connected to the pipeline installed with the circulating centrifugal fan, the pipeline heater, the second thermocouple and the second three-way valve in sequence, the first output end of the second three-way valve is connected to the first three-way valve. The pipeline between the second input ends of the valve is connected to form a temperature-rising desorption loop, and the gas in the pipeline is heated by the pipeline heater, so that the VOCs gas in the VOCs adsorption device can achieve temperature-rising thermal desorption. 5. The vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and a nitrogen source as claimed in claim 1, wherein the first input port and the output port of the first three-way valve are connected, and the second three-way valve When the input end of the valve is connected to the second output end, and the input end of the third three-way valve is connected to the first output end: The first input end of the first three-way valve is connected to the pipeline equipped with the first thermocouple, and the output end of the first three-way valve is connected with the circulating centrifugal fan, the pipeline heater, and the second thermocouple installed in sequence, for After VOCs high-temperature nitrogen is used for primary cooling, the air cooler, the third thermocouple, and the pipeline of the liquid nitrogen condenser are connected, and after passing through the input end and the first output end of the third three-way valve, the fourth thermocouple, The pipeline connection of the fourth on-off valve is connected with the gas input end of the liquid nitrogen storage tank; the pipeline between the liquid output end of the liquid nitrogen storage tank and the liquid nitrogen condenser is also connected in turn for extracting nitrogen liquid for secondary Level cooling liquid nitrogen circulation pump and second switching valve. 6. The vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and a nitrogen source as claimed in claim 5, wherein a pressure gauge is connected to the gas output end of the liquid nitrogen storage tank. 7. The vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and nitrogen source as claimed in claim 5, characterized in that, A VOCs sensor is also installed on the pipeline between the second output end of the second three-way valve and the air cooler. 8. The vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and nitrogen source as claimed in any one of claims 1 to 7, characterized in that, between the output end of the first three-way valve and the circulating fan A gas flow agent is also installed on the pipeline. 9. The vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and nitrogen source as claimed in any one of claims 1 to 7, wherein the VOCs adsorption device is connected to the circulating centrifugal fan and the second between the two thermocouples. 10. The vehicle-mounted VOCs condensation recovery system using liquid nitrogen as a cold source and a nitrogen source as claimed in any one of claims 1 to 7, wherein a third switch valve.