Gas heat exchange system and method

Abstract

The invention relates to a gas heat exchange system and method.The system comprises a first heat exchanger and a second heat exchanger, the first heat exchanger and the second heat exchanger each comprise a shell, a heat storage gas heat exchange pipe and a heat removal gas heat exchange pipe, the heat storage gas heat exchange pipes and the heat removal gas heat exchange pipes are arranged in the shells, and the shells contain liquid heat-conducting media; wherein the heat storage gas heat exchange tube of the first heat exchanger is communicated with the heat storage gas heat exchange tube of the second heat exchanger, and the heat removal gas heat exchange tube of the first heat exchanger is communicated with the heat removal gas heat exchange tube of the second heat exchanger. The system is provided with multiple stages of heat exchangers, uniform heat exchange of low-temperature gas can be achieved, and the heat exchange temperature of the low-temperature gas can be effectively controlled.

Description

Technical Field

[0001] The present disclosure relates to gas heat exchange, and more particularly, to a gas heat exchange system and method. Background Art

[0002] Due to the low thermal conductivity of gases, it is difficult to exchange heat between gases, resulting in a large amount of waste of low-quality heat-carrying gases in industrial processes. The existing gas heat exchange methods require heat exchangers with a variety of different heat exchange specifications, which are costly, have low heat exchange efficiency, and require a large floor area for the equipment. Summary of the Invention

[0003] The object of the present disclosure is to provide a gas heat exchange system and method. The system has a multi-stage heat exchanger, which can achieve uniform and effective heat exchange of low-temperature gases, and avoid the problems of low heat exchange efficiency and non-uniform heat exchange between gases.

[0004] In a first aspect of the present disclosure, a gas heat exchange system is provided. The system includes a first heat exchanger and a second heat exchanger. The first heat exchanger and the second heat exchanger each include a housing and a heat storage gas heat exchange tube and a heat extraction gas heat exchange tube disposed in the housing. The housing contains a liquid heat-conducting medium.

[0005] Wherein, the heat storage gas heat exchange tube of the first heat exchanger is communicated with the heat storage gas heat exchange tube of the second heat exchanger, and the heat extraction gas heat exchange tube of the first heat exchanger is communicated with the heat extraction gas heat exchange tube of the second heat exchanger.

[0006] Optionally, the system further includes a main heat storage gas inlet pipeline, a main heat storage gas outlet pipeline, a main heat extraction gas inlet pipeline, a main heat extraction gas outlet pipeline, a heat storage gas connecting pipe, and a heat extraction gas connecting pipe. The main heat storage gas inlet pipeline is communicated with two heat storage gas inlet branch pipelines. The two heat storage gas inlet branch pipelines are respectively communicated with the inlets of the heat storage gas heat exchange tubes of the first heat exchanger and the second heat exchanger. The main heat storage gas outlet pipeline is communicated with two heat storage gas outlet branch pipelines. The two heat storage gas outlet branch pipelines are respectively communicated with the outlets of the heat storage gas heat exchange tubes of the first heat exchanger and the second heat exchanger. The main heat extraction gas inlet pipeline is communicated with two heat extraction gas inlet branch pipelines. The two heat extraction gas inlet branch pipelines are respectively communicated with the inlets of the heat extraction gas heat exchange tubes of the first heat exchanger and the second heat exchanger. The main heat extraction gas outlet pipeline is communicated with the outlet of the heat extraction gas heat exchange tube of the first heat exchanger. Wherein, valves are respectively provided on the heat storage gas inlet branch pipeline, the heat storage gas outlet branch pipeline, and the heat extraction gas inlet branch pipeline.

[0007] Optionally, the outlet of the heat storage gas heat exchange tube of the first heat exchanger is communicated with the inlet of the heat storage gas heat exchange tube of the second heat exchanger through a heat storage gas connecting pipe, and the outlet of the heat extraction gas heat exchange tube of the second heat exchanger is communicated with the inlet of the heat extraction gas heat exchange tube of the first heat exchanger through a heat extraction gas connecting pipe.

[0008] Optionally, the heat storage gas heat exchange tube and the heat extraction gas heat exchange tube are each independently selected from one or more of a plain tube, a finned tube, a threaded tube, a serpentine tube, and a spiral grooved tube, and the liquid heat conducting medium is selected from heat conducting oil or water.

[0009] Optionally, an intermediate heat exchanger is further included between the first heat exchanger and the second heat exchanger. The intermediate heat exchanger includes the housing and the heat storage gas heat exchange tube and the heat extraction gas heat exchange tube arranged in the housing; both ends of the heat storage gas heat exchange tube of the intermediate heat exchanger are respectively communicated with the heat storage gas heat exchange tubes of the first heat exchanger and the second heat exchanger; both ends of the heat extraction gas heat exchange tube of the intermediate heat exchanger are respectively communicated with the heat extraction gas heat exchange tubes of the first heat exchanger and the second heat exchanger.

[0010] A method for gas heat exchange using the system according to the first aspect of the present disclosure is provided in the second aspect of the present disclosure. The method includes: sequentially introducing the heat storage gas into the heat storage gas heat exchange tubes of the first heat exchanger and the second heat exchanger to store heat in the liquid heat conducting medium in the heat exchanger housing; sequentially introducing the heat extraction gas into the heat extraction gas heat exchange tubes of the second heat exchanger and the first heat exchanger to extract heat.

[0011] Optionally, the initial temperature of the heat storage gas entering the heat storage gas heat exchange tube in the heat storage gas inlet main pipeline is 200 - 500 °C, the initial temperature of the heat extraction gas entering the heat extraction gas heat exchange tube in the heat extraction gas inlet main pipeline is 25 - 100 °C, the temperature of the liquid heat conducting medium is maintained above 60 °C, and the outlet temperature of the heat extraction gas flowing out of the first heat exchanger is above 40 °C; wherein, the liquid heat conducting medium is selected from heat conducting oil or water.

[0012] Optionally, the flow rate ratio of the heat storage gas to the heat extraction gas is 1:(0.01 - 1), preferably 1:(0.01 - 0.5).

[0013] Optionally, the method further includes: monitoring the temperature of the heat storage gas at the outlet of the heat storage gas heat exchange tube. When the outlet temperature of the heat storage gas is below 80 °C, the heat storage gas is returned to the heat storage gas outlet main pipeline through the heat storage gas outlet branch pipeline, and the heat storage gas in the heat storage gas inlet main pipeline enters the heat storage gas heat exchange tube of the downstream heat exchanger through the heat storage gas inlet branch pipeline; when the temperature of the heat storage gas is greater than 80 °C, the heat storage gas enters the heat storage gas heat exchange tube of the downstream heat exchanger.

[0014] Optionally, the method further includes: monitoring the temperature of the liquid heat-conducting medium in all the heat exchanger shells; when the temperature of the liquid heat-conducting medium in all the heat exchangers is above 60°C, allowing the heat-taking gas in the main pipeline of the heat-taking gas inlet to enter the heat-taking gas heat-exchange tubes of each heat exchanger through the branch pipelines of the heat-taking gas inlet; when the temperature of the liquid heat-conducting medium in at least one heat exchanger shell is less than 60°C, closing the valves on all the branch pipelines of the heat-taking gas inlet and stopping supplying the heat-taking gas to all the heat exchangers.

[0015] Through the above technical solution, the present disclosure provides a gas heat-exchange system and method. The system has multiple-stage heat exchangers, which can achieve uniform heat exchange of low-temperature gas and effectively control the heat-exchange temperature of the low-temperature gas, avoiding the problems of low gas-gas heat-exchange efficiency and uneven heat exchange. The method of the present disclosure is simple to operate, has low operating costs, and has strong applicability and popularity.

[0016] Other features and advantages of the present disclosure will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. They are used together with the following specific implementation to explain the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings:

[0018] Figure 1 is a schematic diagram of a specific implementation of the gas heat-exchange system of the present disclosure.

[0019] DESCRIPTION OF THE REFERENCE NUMERALS

[0020] I First heat exchanger C Main pipeline of the heat storage gas outlet

[0021] II Second heat exchanger C1 First branch pipeline of the heat storage gas outlet

[0022] V Intermediate heat exchanger C2 Second branch pipeline of the heat storage gas outlet

[0023] A Main pipeline of the heat storage gas inlet C3 Third branch pipeline of the heat storage gas outlet

[0024] A1 First branch pipeline of the heat storage gas inlet D Main pipeline of the heat-taking gas outlet

[0025] A2 Second branch pipeline of the heat storage gas inlet 1 Heat storage gas heat-exchange tube of the first heat exchanger

[0026] A3 Third branch pipeline of the heat storage gas inlet 2 Heat-taking gas heat-exchange tube of the first heat exchanger

[0027] B Main pipeline of the heat-taking gas inlet 3 Heat storage gas heat-exchange tube of the intermediate heat exchanger

[0028] B1 The first heat extraction gas inlet branch pipeline 4 The heat extraction gas heat exchange tubes of the intermediate heat exchanger

[0029] B2 The second heat extraction gas inlet branch pipeline 5 The heat storage gas heat exchange tubes of the second heat exchanger

[0030] B3 The third heat extraction gas inlet branch pipeline 6 The heat extraction gas heat exchange tubes of the second heat exchanger Specific embodiments

[0031] The following will describe in detail the specific embodiments of the present disclosure with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustration and explanation of the present disclosure, and are not intended to limit the present disclosure.

[0032] In the first aspect of the present disclosure, a gas heat exchange system is provided, as Figure 1 shown. The system includes a first heat exchanger I and a second heat exchanger II. The first heat exchanger I and the second heat exchanger II each include a housing and heat storage gas heat exchange tubes and heat extraction gas heat exchange tubes disposed within the housing. The housing contains a liquid heat-conducting medium. Among them, the heat storage gas heat exchange tubes 1 of the first heat exchanger are connected to the heat storage gas heat exchange tubes 5 of the second heat exchanger, and the heat extraction gas heat exchange tubes 2 of the first heat exchanger are connected to the heat extraction gas heat exchange tubes 6 of the second heat exchanger.

[0033] The present disclosure provides a gas heat exchange system. The system has multiple-stage heat exchangers, which can achieve uniform heat exchange of low-temperature gas and effectively control the heat exchange temperature of the low-temperature gas, avoiding the problems of low gas-gas heat exchange efficiency and uneven heat exchange.

[0034] In an embodiment of the present disclosure, the system further includes a main inlet pipeline A for heat storage gas, a main outlet pipeline C for heat storage gas, a main inlet pipeline B for heat extraction gas, a main outlet pipeline D for heat extraction gas, a heat storage gas connecting pipe, and a heat extraction gas connecting pipe. In a specific embodiment, the main inlet pipeline A for heat storage gas is connected to two branch inlet pipelines for heat storage gas, such as A1 and A3. One of the branch inlet pipelines A1 for heat storage gas is connected to the inlet of the heat storage gas heat exchange tube 1 of the first heat exchanger, and the other branch inlet pipeline A3 for heat storage gas is connected to the inlet of the heat storage gas heat exchange tube 5 of the second heat exchanger. The main outlet pipeline C for heat storage gas is connected to two branch outlet pipelines for heat storage gas, such as C1 and C3. One of the branch outlet pipelines C1 for heat storage gas is connected to the outlet of the heat storage gas heat exchange tube 1 of the first heat exchanger, and the other branch outlet pipeline C3 for heat storage gas is connected to the outlet of the heat storage gas heat exchange tube 5 of the second heat exchanger. The main inlet pipeline B for heat extraction gas is connected to two branch inlet pipelines for heat extraction gas, such as B1 and B3. One of the branch inlet pipelines B3 for heat extraction gas is connected to the inlet of the heat extraction gas heat exchange tube 2 of the first heat exchanger, and the other branch inlet pipeline B1 for heat extraction gas is connected to the inlet of the heat extraction gas heat exchange tube 6 of the second heat exchanger. The main outlet pipeline D for heat extraction gas is connected to the outlet of the heat extraction gas heat exchange tube 2 of the first heat exchanger. Among them, valves are respectively arranged on the branch inlet pipelines for heat storage gas (such as A1 and A3), the branch outlet pipelines for heat storage gas (such as C1 and C3), and the branch inlet pipelines for heat extraction gas (such as B1 and B3) to control the flow directions of the heat storage gas and the heat extraction gas. In the above embodiment, by selecting the preferred branch inlet pipelines for heat storage gas, the branch outlet pipelines for heat storage gas, and the branch inlet pipelines for heat extraction gas, the heat storage gas can directly enter the second heat exchanger for heat storage without passing through the first heat exchanger, and the heat extraction gas can directly enter the first heat exchanger for heat extraction without passing through the second heat exchanger, thereby improving the heat exchange efficiency.

[0035] In an embodiment of the present disclosure, the outlet of the heat storage gas heat exchange tube 1 of the first heat exchanger is connected to the inlet of the heat storage gas heat exchange tube 5 of the second heat exchanger through a heat storage gas connecting pipe, and the outlet of the heat extraction gas heat exchange tube 6 of the second heat exchanger is connected to the inlet of the heat extraction gas heat exchange tube 2 of the first heat exchanger through a heat extraction gas connecting pipe. In the above embodiment, the heat storage gas and the heat extraction gas flow in opposite directions, which is beneficial to full heat exchange and improves the heat exchange efficiency. Among them, the flow direction of the heat storage gas is from the heat storage gas heat exchange tube 1 of the first heat exchanger, through the heat storage gas connecting pipe, and to the heat storage gas heat exchange tube 5 of the second heat exchanger, and the flow direction of the heat extraction gas is from the heat extraction gas heat exchange tube 6 of the second heat exchanger, through the heat extraction gas connecting pipe, and to the heat extraction gas heat exchange tube 2 of the first heat exchanger.

[0036] In an embodiment of the present disclosure, the heat storage gas heat exchange tube and the heat extraction gas heat exchange tube are each independently selected from one or more of a plain tube, a finned tube, a threaded tube, a serpentine tube, and a spiral groove tube, and the liquid heat transfer medium is selected from heat transfer oil or water. In a preferred embodiment, the heat exchange tube is one or more of a threaded tube, a serpentine tube, and a spiral groove tube. In the above embodiment, by selecting the preferred heat exchange tube and heat transfer medium, the heat exchange efficiency can be further improved.

[0037] In an embodiment of the present disclosure, an intermediate heat exchanger V is further included between the first heat exchanger and the second heat exchanger. The intermediate heat exchanger V includes the housing and the heat storage gas heat exchange tube 3 and the heat extraction gas heat exchange tube 4 disposed in the housing; both ends of the heat storage gas heat exchange tube 3 of the intermediate heat exchanger are respectively communicated with the heat storage gas heat exchange tubes of the first heat exchanger and the second heat exchanger; both ends of the heat extraction gas heat exchange tube 4 of the intermediate heat exchanger are respectively communicated with the heat extraction gas heat exchange tubes of the first heat exchanger and the second heat exchanger. In an embodiment, the inlet of the heat storage gas heat exchange tube 3 of the intermediate heat exchanger is communicated with the outlet of the heat storage gas heat exchange tube 1 of the first heat exchanger through a heat storage gas connecting pipe, and the outlet of the heat storage gas heat exchange tube 3 of the intermediate heat exchanger is communicated with the inlet of the heat storage gas heat exchange tube 5 of the second heat exchanger through a heat storage gas connecting pipe, so that the heat storage gas enters from the inlet of the heat storage gas heat exchange tube 1 of the first heat exchanger and flows through the intermediate heat exchanger V to the second heat exchanger II; the inlet of the heat extraction gas heat exchange tube 4 of the intermediate heat exchanger is communicated with the outlet of the heat extraction gas heat exchange tube 6 of the second heat exchanger through a heat extraction gas connecting pipe, and the outlet of the heat extraction gas heat exchange tube 4 of the intermediate heat exchanger is communicated with the inlet of the heat extraction gas heat exchange tube 2 of the first heat exchanger through a heat extraction gas connecting pipe, so that the heat extraction gas enters from the inlet of the heat extraction gas heat exchange tube 6 of the second heat exchanger and flows through the intermediate heat exchanger V to the first heat exchanger I. In the above embodiment, the number of intermediate heat exchangers is not limited and can be adjusted according to actual needs. For example, the number of intermediate heat exchangers can be 4 to 10, preferably 4 to 6.

[0038] A method for gas heat exchange using the system described in the first aspect of the present disclosure is provided in the second aspect of the present disclosure. The method includes: sequentially introducing the heat storage gas into the heat storage gas heat exchange tubes of the first heat exchanger I and the second heat exchanger II to store heat in the liquid heat transfer medium in the heat exchanger housing; sequentially introducing the heat extraction gas into the heat extraction gas heat exchange tubes of the second heat exchanger II and the first heat exchanger I to extract heat.

[0039] The method of the present disclosure is simple to operate, has high heat exchange efficiency, low operating cost, and has strong applicability and popularization.

[0040] In an embodiment of the present disclosure, the heat storage process may include: allowing the heat storage gas in the main heat storage gas inlet pipeline A to enter the first heat exchanger I through the inlet of the heat storage gas heat exchange tube 1 of the first heat exchanger, passing through the outlet of the heat storage gas heat exchange tube 1 of the first heat exchanger, the heat storage gas connecting pipe, and the inlet of the heat storage gas heat exchange tube 5 of the second heat exchanger to enter the second heat exchanger II, and entering the main heat storage gas outlet pipeline C from the outlet of the heat storage gas heat exchange tube 5 of the second heat exchanger;

[0041] The heat extraction process may include: allowing the heat extraction gas in the main heat extraction gas inlet pipeline B to enter the second heat exchanger II through the inlet of the heat extraction gas heat exchange tube 6 of the second heat exchanger, passing through the outlet of the heat extraction gas heat exchange tube 6 of the second heat exchanger, the heat extraction gas connecting pipe, and the inlet of the heat extraction gas heat exchange tube 2 of the first heat exchanger to enter the first heat exchanger I, and entering the main heat extraction gas outlet pipeline D from the outlet of the heat extraction gas heat exchange tube 2 of the first heat exchanger.

[0042] In an embodiment of the present disclosure, the initial temperature of the heat storage gas in the main heat storage gas inlet pipeline A entering the heat storage gas heat exchange tubes (such as 1, 3, 5) is 200 - 500 °C, and the initial temperature of the heat extraction gas in the main heat extraction gas inlet pipeline B entering the heat extraction gas heat exchange tubes (such as 2, 4, 6) is 25 - 100 °C, for example, it can be 25 - 35 °C, 80 - 95 °C; the temperature of the liquid heat conducting medium is maintained above 60 °C, and the outlet temperature of the heat extraction gas flowing out of the first heat exchanger I is above 40 °C; wherein, the liquid heat conducting medium is selected from heat conducting oil or water. In the above embodiment, by selecting the heat storage gas with a preferred temperature, it is beneficial to keep the temperature of the liquid heat conducting medium above 60 °C all the time, so that the heat extraction gas can extract heat.

[0043] In an embodiment of the present disclosure, the flow rate ratio of the heat storage gas to the heat extraction gas is 1:(0.01 - 1), preferably 1:(0.01 - 0.5). In the above embodiment, by adjusting the flow rate ratio of the heat storage gas and the heat extraction gas, the temperature of the liquid heat conducting medium can be controlled, so that the heat storage gas and the heat extraction gas can exchange heat evenly and effectively.

[0044] In an embodiment of the present disclosure, monitor the temperature of the heat storage gas at the outlet of the heat storage gas heat exchange tube. When the outlet temperature of the heat storage gas is below 80 °C, make this heat storage gas not enter the downstream heat exchanger, but return to the main heat storage gas outlet pipeline C through the heat storage gas outlet branch pipeline (such as C1 or C2), and make the heat storage gas in the main heat storage gas inlet pipeline A enter the heat storage gas heat exchange tube of the downstream heat exchanger through the heat storage gas inlet branch pipeline (such as A2 or A3); in another embodiment, when the temperature of the heat storage gas at the outlet of the heat storage gas heat exchange tube is greater than 80 °C, make this heat storage gas enter the heat storage gas heat exchange tube of the downstream heat exchanger.

[0045] In a preferred embodiment, when the temperature of the heat storage gas at the outlet of the heat storage gas heat exchange tube is 80-100 °C, this stream of heat storage gas is made to continue to enter the heat storage gas heat exchange tubes of the downstream heat exchanger, and the heat storage gas in the main heat storage gas inlet pipeline A also enters the heat storage gas heat exchange tubes of the downstream heat exchanger through the heat storage gas inlet branch pipelines (such as A2 or A3); wherein, with the flow direction of the heat storage gas as the reference, the upstream refers to the end where the heat storage gas enters the system, and the downstream refers to the end where the heat storage gas discharges from the system. In the above embodiment, by monitoring the temperature of the heat storage gas, the flow direction of the heat storage gas can be adjusted, and the heat storage gas that has not passed through the heat exchanger can be supplemented into the downstream heat exchanger to keep the temperature of the liquid heat-conducting medium always above 60 °C.

[0046] In an embodiment of the present disclosure, the method further includes: monitoring the temperature of the liquid heat-conducting medium in all the heat exchanger shells, and when the temperatures of the liquid heat-conducting media in all the heat exchangers reach above 60 °C, making the heat extraction gas in the main heat extraction gas inlet pipeline B enter the heat extraction gas heat exchange tubes of each heat exchanger through the heat extraction gas inlet branch pipelines (such as B1 or B3) for heat extraction. When the temperature of the liquid heat-conducting medium in at least one heat exchanger shell is less than 60 °C, the valves on all the heat extraction gas inlet branch pipelines (such as B1 and B3) are closed, the supply of heat extraction gas to all the heat exchangers is stopped, and no new heat extraction gas is introduced into the system; when the temperatures of the liquid heat-conducting media in all the heat exchanger shells rise to above 60 °C, the valves on the heat extraction gas inlet branch pipelines (such as B1 and B3) are opened, and the supply of heat extraction gas is resumed.

[0047] In the specific implementation manner, the heat storage gas can be first introduced into the system to heat the liquid heat-conducting medium in the heat exchanger, and when the temperatures of the liquid heat-conducting media in all the heat exchangers rise to above 60 °C, the heat extraction gas is then introduced for heat extraction. In the preferred embodiment, the temperatures of the liquid heat-conducting media in all the heat exchangers are always kept above 60 °C.

[0048] In a further embodiment, when the temperature of the liquid heat-conducting medium in the intermediate heat exchanger V and / or the first heat exchanger I shell is above 90 °C, a stream of heat extraction gas directly from the main heat extraction gas inlet pipeline B is introduced into this heat exchanger to enhance the heat extraction effect. In the above embodiment, when the temperature of the liquid heat-conducting medium is overheated, the heat extraction gas that has not passed through the heat exchanger is supplemented into the heat exchanger for heat extraction.

[0049] The present disclosure is further described in detail below through examples. The raw materials used in the examples can all be obtained through commercial purchase channels.

[0050] Example 1

[0051] A gas heat exchange system, such asFigure 1 As shown in Figure 1 , the method for gas heat exchange using this system includes the following steps:

[0052] (1) Let the heat storage gas at a temperature of 400 °C in the main heat storage gas inlet pipeline A enter the heat storage gas heat exchange tube 1 of the first heat exchanger through the first heat storage gas inlet branch pipeline A1, and perform primary heat storage on the heat transfer oil in the shell of the first heat exchange tube I. After primary heat storage, the temperature of the heat transfer oil in the shell of the first heat exchange tube I is 150 °C, and the temperature of the heat storage gas at the outlet of the heat storage gas heat exchange tube 1 is 300 °C; Let the heat storage gas at a temperature of 300 °C enter the intermediate heat exchanger V through the first heat storage gas connecting pipe, and enter the heat storage gas heat exchange tube 3 of the intermediate heat exchanger together with the heat storage gas from the main heat storage gas inlet pipeline A and entering the intermediate heat exchanger V through the second heat storage gas inlet branch pipeline A2, and perform secondary heat storage on the heat transfer oil in the shell of the intermediate heat exchanger V. After secondary heat storage, the temperature of the heat transfer oil in the shell of the intermediate heat exchanger V is 140 °C, and the temperature of the heat storage gas at the outlet of the heat storage gas heat exchange tube 3 is 250 °C; Let the heat storage gas at a temperature of 250 °C enter the second heat exchanger II through the second heat storage gas connecting pipe, and enter the heat storage gas heat exchange tube 5 of the second heat exchanger together with the heat storage gas from the main heat storage gas inlet pipeline A and entering the second heat exchanger II through the third heat storage gas inlet branch pipeline A3, and perform tertiary heat storage on the heat transfer oil in the shell of the second heat exchanger II. After tertiary heat storage, the temperature of the heat transfer oil in the shell of the second heat exchanger II is 130 °C, and the temperature of the heat storage gas at the outlet of the heat storage gas heat exchange tube 5 is 220 °C; Let the heat storage gas at a temperature of 220 °C return to the main heat storage gas outlet pipeline C through the third heat storage gas outlet branch pipeline C3;

[0053] (2) Detect the temperatures of the heat transfer oils in the three heat exchangers. When the temperatures of the heat transfer oils in the three heat exchangers all reach above 60 °C, let the heat extraction gas at a temperature of 25 °C in the main heat extraction gas inlet pipeline B enter the heat extraction gas heat exchange tube 6 of the second heat exchanger through the first heat extraction gas inlet branch pipeline B1 for primary heat extraction. After primary heat extraction, the temperature of the heat transfer oil in the shell of the second heat exchanger II is 125 °C; Let the heat extraction gas after primary heat extraction enter the heat extraction gas heat exchange tube 4 of the intermediate heat exchange tube through the first heat extraction gas connecting pipe for secondary heat extraction. After secondary heat extraction, the temperature of the heat transfer oil in the shell of the intermediate heat exchanger V is 136 °C; Let the heat extraction gas after secondary heat extraction enter the first heat exchanger I through the second heat extraction gas connecting pipe, and let the heat extraction gas directly from the main heat extraction gas inlet pipeline B and entering the first heat exchanger I through the third heat extraction gas inlet branch pipeline B3 enter the heat extraction gas heat exchange tube 2 of the first heat exchange tube together for tertiary heat extraction. After tertiary heat extraction, the temperature of the heat transfer oil in the shell of the first heat exchanger I is 138 °C, and the outlet temperature of the heat extraction gas flowing out of the first heat exchanger I after tertiary heat extraction is 85 °C; Let the heat extraction gas after tertiary heat extraction return to the main heat extraction gas outlet pipeline D;

[0054] Among them, in the same heat exchanger, the ratio of the flow rate of the heat storage gas in the heat storage gas heat exchange tube to the flow rate of the heat extraction gas in the heat extraction gas heat exchange tube is 1:0.4. The main inlet pipeline A of the heat storage gas is respectively connected to the first branch inlet pipeline A1 of the heat storage gas, the second branch inlet pipeline A2 of the heat storage gas, and the third branch inlet pipeline A3 of the heat storage gas; the main inlet pipeline B of the heat extraction gas is respectively connected to the first branch inlet pipeline B1 of the heat extraction gas, the second branch inlet pipeline B2 of the heat extraction gas, and the third branch inlet pipeline B3 of the heat extraction gas; the main outlet pipeline C of the heat storage gas is respectively connected to the first branch outlet pipeline C1 of the heat storage gas, the second branch outlet pipeline C2 of the heat storage gas, and the third branch outlet pipeline C3 of the heat storage gas; the main outlet pipeline D of the heat extraction gas is connected to the outlet of the heat extraction gas heat exchange tube 2 of the first heat exchanger; valves are respectively provided on the first branch inlet pipeline A1 of the heat storage gas, the second branch inlet pipeline A2 of the heat storage gas, the third branch inlet pipeline A3 of the heat storage gas, the first branch inlet pipeline B1 of the heat extraction gas, the second branch inlet pipeline B2 of the heat extraction gas, the third branch inlet pipeline B3 of the heat extraction gas, the first branch outlet pipeline C1 of the heat storage gas, the second branch outlet pipeline C2 of the heat storage gas, and the third branch outlet pipeline C3 of the heat storage gas.

[0055] Example 2

[0056] The same as Example 1, the difference is only that there are 3 intermediate heat exchangers. The initial temperature of the heat storage gas entering the first heat exchanger I in the main inlet pipeline A of the heat storage gas is 500 °C, and the outlet temperature of the heat storage gas flowing out of the outlet of the heat storage gas heat exchange tube 5 of the second heat exchanger after multi-stage heat storage is 280 °C; the initial temperature of the heat extraction gas entering the second heat exchanger II in the main inlet pipeline B of the heat extraction gas is 95 °C, and the outlet temperature of the heat extraction gas flowing out of the outlet of the heat extraction gas heat exchange tube 2 of the first heat exchanger after multi-stage heat extraction is 200 °C; the temperature of the heat transfer oil in all heat exchangers is above 180 °C; in the same heat exchanger, the ratio of the flow rate of the heat storage gas in the heat storage gas heat exchange tube to the flow rate of the heat extraction gas in the heat extraction gas heat exchange tube is 1:0.2.

[0057] Comparative Example 1

[0058] The same as Example 1, the difference is only that the heat exchanger is replaced with a shell-and-tube heat exchanger, in which the heat storage gas is inside the shell of the shell-and-tube heat exchanger and the heat extraction gas is inside the tube.

[0059] Test Example

[0060] The test method for the heat exchange efficiency of the systems in the examples and comparative examples is Among them,

[0061] c 1 and c 2 respectively represent the specific heat capacities of the heat storage gas and the heat extraction gas, and the unit of both is J / (kg·°C);

[0062] q n represents the flow rate of the heat storage gas entering the heat exchange system each time, with the unit of Nm 3 / h;

[0063] q’ n represents the flow rate of the heat extraction gas entering the heat exchange system each time, with the unit of Nm 3 / h;

[0064] t 0 and t 1 respectively represent the initial temperature and the final temperature of the heat storage gas entering the heat exchange system, with the unit of °C;

[0065] t’ 0 and t’ 1 respectively represent the initial temperature and the final temperature of the heat extraction gas entering the heat exchange system, with the unit of °C;

[0066] T 0 and T 1 represent the temperatures of the heat conduction medium before and after heat storage, with the unit of °C;

[0067] T 2 and T 3 represent the temperatures of the heat conduction medium before and after heat extraction, with the unit of °C.

[0068] The test results are as follows:

[0069] Heat transfer efficiency, % Example 1 45 Example 2 60 Comparative Example 1 30

[0070] From the comparison of the data between Examples 1-2 and Comparative Example 1, it can be seen that Examples 1-2 using the system of the present disclosure can achieve uniform heat exchange of low-temperature gases and improve the heat exchange efficiency. While Comparative Example 1 does not use the system of the present disclosure, the gas-gas heat exchange efficiency is low and the heat exchange is uneven.

[0071] The preferred embodiments of the present disclosure have been described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0072] In addition, it should be noted that, in the above specific embodiments, the various specific technical features described can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination methods.

[0073] Furthermore, any combination can be made between various different embodiments of the present disclosure as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

Claims

1. A gas heat exchange system, characterized in that, the system includes a first heat exchanger and a second heat exchanger. The first heat exchanger and the second heat exchanger respectively include a housing and a heat storage gas heat exchange tube and a heat extraction gas heat exchange tube arranged in the housing. The housing contains a liquid heat conducting medium; wherein, the heat storage gas heat exchange tube of the first heat exchanger is communicated with the heat storage gas heat exchange tube of the second heat exchanger, and the heat extraction gas heat exchange tube of the first heat exchanger is communicated with the heat extraction gas heat exchange tube of the second heat exchanger.

2. The system according to claim 1, characterized in that, the system further includes a main heat storage gas inlet pipeline, a main heat storage gas outlet pipeline, a main heat extraction gas inlet pipeline, a main heat extraction gas outlet pipeline, a heat storage gas connecting pipe and a heat extraction gas connecting pipe; the main heat storage gas inlet pipeline is communicated with two heat storage gas inlet branch pipelines, and the two heat storage gas inlet branch pipelines are respectively communicated with the inlets of the heat storage gas heat exchange tubes of the first heat exchanger and the second heat exchanger; the main heat storage gas outlet pipeline is communicated with two heat storage gas outlet branch pipelines, and the two heat storage gas outlet branch pipelines are respectively communicated with the outlets of the heat storage gas heat exchange tubes of the first heat exchanger and the second heat exchanger; the main heat extraction gas inlet pipeline is communicated with two heat extraction gas inlet branch pipelines, and the two heat extraction gas inlet branch pipelines are respectively communicated with the inlets of the heat extraction gas heat exchange tubes of the first heat exchanger and the second heat exchanger; the main heat extraction gas outlet pipeline is communicated with the outlet of the heat extraction gas heat exchange tube of the first heat exchanger; wherein, valves are respectively arranged on the heat storage gas inlet branch pipeline, the heat storage gas outlet branch pipeline and the heat extraction gas inlet branch pipeline.

3. The system according to claim 2, characterized in that, the outlet of the heat storage gas heat exchange tube of the first heat exchanger is communicated with the inlet of the heat storage gas heat exchange tube of the second heat exchanger through a heat storage gas connecting pipe, and the outlet of the heat extraction gas heat exchange tube of the second heat exchanger is communicated with the inlet of the heat extraction gas heat exchange tube of the first heat exchanger through a heat extraction gas connecting pipe.

4. The system according to claim 1, characterized in that, the heat storage gas heat exchange tube and the heat extraction gas heat exchange tube are each independently selected from one or more of a plain tube, a finned tube, a threaded tube, a serpentine tube and a spiral groove tube, and the liquid heat conducting medium is selected from heat conducting oil or water.

5. The system according to claim 1, characterized in that, an intermediate heat exchanger is further included between the first heat exchanger and the second heat exchanger. The intermediate heat exchanger includes the housing and a heat storage gas heat exchange tube and a heat extraction gas heat exchange tube arranged in the housing; both ends of the heat storage gas heat exchange tube of the intermediate heat exchanger are respectively communicated with the heat storage gas heat exchange tubes of the first heat exchanger and the second heat exchanger; both ends of the heat extraction gas heat exchange tube of the intermediate heat exchanger are respectively communicated with the heat extraction gas heat exchange tubes of the first heat exchanger and the second heat exchanger.

6. A method for gas heat exchange using the system according to any one of claims 1 to 5, characterized in that, The method includes: enabling the heat storage gas to sequentially enter the heat storage gas heat exchange tubes of the first heat exchanger and the second heat exchanger to store heat for the liquid heat-conducting medium in the heat exchanger housing; enabling the heat extraction gas to sequentially enter the heat extraction gas heat exchange tubes of the second heat exchanger and the first heat exchanger to extract heat.

7. The method according to claim 6, wherein, the initial temperature of the heat storage gas entering the heat storage gas heat exchange tube in the main pipeline of the heat storage gas inlet is 200 - 500 °C, the initial temperature of the heat extraction gas entering the heat extraction gas heat exchange tube in the main pipeline of the heat extraction gas inlet is 25 - 100 °C, the temperature of the liquid heat-conducting medium is maintained above 60 °C, and the outlet temperature of the heat extraction gas flowing out of the first heat exchanger is above 40 °C; wherein, the liquid heat-conducting medium is selected from heat-conducting oil or water.

8. The method according to claim 6, wherein, the flow rate ratio of the heat storage gas to the heat extraction gas is 1:(0.01 - 1), preferably 1:(0.01 - 0.5).

9. The method according to claim 6, wherein, the method further includes: monitoring the temperature of the heat storage gas at the outlet of the heat storage gas heat exchange tube, when the outlet temperature of the heat storage gas is below 80 °C, enabling the heat storage gas to return to the main pipeline of the heat storage gas outlet through the branch pipeline of the heat storage gas outlet, and enabling the heat storage gas in the main pipeline of the heat storage gas inlet to enter the heat storage gas heat exchange tube of the downstream heat exchanger through the branch pipeline of the heat storage gas inlet; when the temperature of the heat storage gas is greater than 80 °C, enabling the heat storage gas to enter the heat storage gas heat exchange tube of the downstream heat exchanger.

10. The method according to claim 6, wherein, the method further includes: monitoring the temperature of the liquid heat-conducting medium in all heat exchanger housings, when the temperature of the liquid heat-conducting medium in all heat exchangers is above 60 °C, enabling the heat extraction gas in the main pipeline of the heat extraction gas inlet to enter the heat extraction gas heat exchange tubes of each heat exchanger through the branch pipeline of the heat extraction gas inlet; when the temperature of the liquid heat-conducting medium in at least one heat exchanger housing is less than 60 °C, closing the valves on all branch pipelines of the heat extraction gas inlet and stopping supplying the heat extraction gas to all heat exchangers.

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