Bypass flue gas heat exchanger
The bypass flue gas heat exchanger addresses temperature control issues in molten salt and thermal oil heat storage by adjusting flue gas flow rates, ensuring optimal operation and preventing overheating.
Patent Information
- Application Number
- CN202420676527.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2024-03-12
- Filing Date
- 2024-04-03
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2034-04-03
AI Technical Summary
Existing molten salt and thermal oil heat storage technologies face issues with temperature control, as flue gas temperatures often exceed the optimal utilization ranges of molten salt (180-500°C) and thermal oil (maximum 335°C), leading to inefficient operation and potential damage.
A bypass flue gas heat exchanger with adjustable doors and expansion joints is used to control flue gas flow rates into separate bypass flues, allowing for independent temperature adjustment of molten salt and thermal oil heat exchangers, ensuring they operate within their optimal temperature ranges.
The system effectively maintains optimal temperatures for both molten salt and thermal oil heat exchangers, enhancing efficiency and preventing overheating, while reducing heat loss and mechanical stress.
Smart Images
Figure CN222210366U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of flue gas energy storage, and in particular relates to a bypass flue gas heat exchanger. Background Art
[0002] Both molten salt heat storage technology and thermal oil heat storage technology are new technologies that utilize high-temperature flue gas for energy storage and recycling. At present, molten salt heat storage technology or thermal oil heat storage technology is often used in industrial parks to store part of the heat in the high-temperature flue gas generated by the boiler, so as to release heat at the downstream process, thereby providing heat to the downstream process. Among them, the optimal utilization temperature range of ternary molten salt is 180-500°C, and the maximum film temperature of thermal oil is no more than 335°C. However, when the flue gas is currently passed into the molten salt heat exchanger or the thermal oil heat exchanger, there is not much control, so that the actual temperature of the ternary molten salt may exceed the optimal utilization temperature range, or the actual temperature of the thermal oil may exceed the maximum film temperature. Utility Model Content
[0003] In order to overcome the defects of the prior art, the utility model provides a bypass flue gas heat exchanger, which can enable a molten salt heat exchanger and a thermal oil heat exchanger to operate at different loads.
[0004] The purpose of the utility model is achieved through the following technical solutions:
[0005] A bypass flue gas heat exchanger is arranged on a main flue, one end of the main flue is connected to a flue gas output end of a boiler, and the bypass flue gas heat exchanger comprises:
[0006] a first bypass flue, wherein a first end of the first bypass flue is connected to an end of the main flue close to the boiler, a second end of the first bypass flue is connected to an end of the main flue far from the boiler, a first electric regulating door is provided at the first end of the first bypass flue, and a molten salt heat exchanger is provided in the first bypass flue;
[0007] a second bypass flue, wherein a first end of the second bypass flue is connected to an end of the main flue close to the boiler, a second end of the second bypass flue is connected to an end of the main flue far from the boiler, a second electric regulating door is provided at the first end of the second bypass flue, and a heat transfer oil heat exchanger is provided in the second bypass flue;
[0008] A controller is electrically connected to the first electric adjustment door and the second electric adjustment door.
[0009] In one embodiment, a third electric adjustable door electrically connected to the controller is provided in the main flue, and the two ends of the third electric adjustable door are respectively connected to the first end and the second end of the first bypass flue, and the two ends of the third electric adjustable door are respectively connected to the first end and the second end of the second bypass flue.
[0010] The beneficial effects of adopting the above technical solution are: the third electric regulating door in the main flue can cooperate with the first electric regulating door in the first bypass flue to adjust the flue gas flow rate entering the first bypass flue from the main flue, thereby facilitating the adjustment of the flue gas temperature in the first bypass flue; the third electric regulating door in the main flue can also cooperate with the second electric regulating door in the second bypass flue to adjust the flue gas flow rate entering the second bypass flue from the main flue, thereby facilitating the adjustment of the flue gas temperature in the second bypass flue.
[0011] In one embodiment, a first electric shutoff door and a second electric shutoff door are respectively provided at the first end and the second end of the first bypass flue, and the first electric shutoff door and the second electric shutoff door are both electrically connected to the controller.
[0012] The beneficial effect of adopting the above technical solution is that the first electric shut-off door and the second electric shut-off door can respectively close the first end and the second end of the first bypass flue, so that the flue gas of the main flue cannot enter the first bypass flue, which is conducive to stopping the molten salt heat exchanger.
[0013] In one embodiment, a third electric shutoff door and a fourth electric shutoff door are respectively provided at the first end and the second end of the second bypass flue, and the third electric shutoff door and the fourth electric shutoff door are both electrically connected to the controller.
[0014] The beneficial effect of adopting the above technical solution is that the third electric shut-off door and the fourth electric shut-off door can respectively close the first end and the second end of the second bypass flue, so that the flue gas of the main flue cannot enter the second bypass flue, which is conducive to stopping the operation of the thermal oil heat exchanger.
[0015] In one embodiment, a first expansion joint is disposed at both the first end and the second end of the first bypass flue.
[0016] The beneficial effect of adopting the above technical solution is that the first expansion joint can absorb the expansion of the first bypass flue due to heat, so as to prevent the first bypass flue and the main flue from being torn apart.
[0017] In one embodiment, a second expansion joint is disposed at both the first end and the second end of the second bypass flue.
[0018] The beneficial effect of adopting the above technical solution is that the second expansion joint can absorb the expansion of the second bypass flue due to heat, so as to prevent the second bypass flue and the main flue from being torn apart.
[0019] In one embodiment, the heat exchange pipe of the molten salt heat exchanger is arranged in a winding manner in the first bypass flue.
[0020] The beneficial effect of adopting the above technical solution is that the heat exchange pipe of the molten salt heat exchanger is arranged in a winding manner in the first bypass flue, so that the heat exchange surface of the molten salt heat exchanger is larger, which is beneficial to improving the heat exchange efficiency of the molten salt heat exchanger.
[0021] In one embodiment, the heat exchange pipe of the thermal oil heat exchanger is arranged in a winding manner in the second bypass flue.
[0022] The beneficial effect of adopting the above technical solution is that the heat exchange pipe of the thermal oil heat exchanger is arranged in a winding manner in the second bypass flue, so that the heat exchange surface of the thermal oil heat exchanger is larger, which is beneficial to improving the heat exchange efficiency of the thermal oil heat exchanger.
[0023] In one embodiment, a thermal insulation layer is disposed on the outer sides of the first bypass flue and the second bypass flue.
[0024] The beneficial effect of adopting the above technical solution is that the thermal insulation layer can reduce heat loss, so that the heat can be transferred to the molten salt heat exchanger and the thermal oil heat exchanger as much as possible.
[0025] In one embodiment, the first bypass flue and the second bypass flue are both connected inside the enclosure wall.
[0026] The beneficial effects of the utility model are:
[0027] The first electric regulating door and the second electric regulating door can respectively adjust the flue gas flow entering the first bypass flue and the second bypass flue from the main flue by changing the opening, so as to meet the requirements of the molten salt heat exchanger and the thermal oil heat exchanger operating at different loads, thereby facilitating the temperature of the ternary molten salt in the molten salt heat exchanger to be in the optimal utilization temperature range, and also facilitating the temperature of the thermal oil heat exchanger not exceeding the maximum membrane temperature, thereby ensuring the normal operation of the molten salt heat exchanger and the thermal oil heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings.
[0029] in:
[0030] Figure 1 The schematic diagram of the structure of the utility model is shown;
[0031] Figure 2 Shows Figure 1 Right view of;
[0032] In the drawings, like reference numerals are used for like parts. The drawings are not necessarily to scale.
[0033] Reference numerals:
[0034] 1-main flue, 2-first expansion joint, 3-first electric shut-off door, 4-first electric regulating door, 5-first bypass flue, 6-molten salt heat exchanger, 7-second electric shut-off door, 8-third electric regulating door, 9-thermal oil heat exchanger, 10-second bypass flue, 11-third electric shut-off door, 12-enclosing wall. DETAILED DESCRIPTION
[0035] The utility model will be further described below in conjunction with the accompanying drawings.
[0036] The utility model provides a bypass flue gas heat exchanger, such as Figure 1 and Figure 2 As shown, it is arranged on the main flue 1, one end of the main flue 1 is connected to the flue gas output end of the boiler, and the bypass flue gas heat exchanger includes:
[0037] a first bypass flue 5, wherein a first end of the first bypass flue 5 is connected to an end of the main flue 1 close to the boiler, a second end of the first bypass flue 5 is connected to an end of the main flue 1 away from the boiler, a first electric regulating door 4 is provided at the first end of the first bypass flue 5, and a molten salt heat exchanger 6 is provided in the first bypass flue 5;
[0038] a second bypass flue 10, wherein a first end of the second bypass flue 10 is connected to an end of the main flue 1 close to the boiler, a second end of the second bypass flue 10 is connected to an end of the main flue 1 far from the boiler, a second electric regulating door is provided at the first end of the second bypass flue 10, and a heat transfer oil heat exchanger 9 is provided in the second bypass flue 10;
[0039] A controller is electrically connected to the first electric regulating door 4 and the second electric regulating door.
[0040] It can be understood that the first electric regulating door 4 and the second electric regulating door can respectively adjust the flue gas flow entering the first bypass flue 5 and the second bypass flue 10 from the main flue 1 by changing the opening, so as to respectively meet the requirements of the molten salt heat exchanger 6 and the thermal oil heat exchanger 9 to operate at 0-100% load, thereby facilitating the temperature of the ternary molten salt in the molten salt heat exchanger 6 to be in the optimal utilization temperature range, and also facilitating the temperature of the thermal oil heat exchanger 9 not exceeding the maximum film temperature, thereby ensuring the normal operation of the molten salt heat exchanger 6 and the thermal oil heat exchanger 9.
[0041] It should be noted that the temperature of the high-temperature flue gas output from the flue gas output end of the boiler is 600-800°C, and a group of heating surfaces are arranged in parallel between the main flue 1, the first bypass flue 5 and the second bypass flue 10, and according to the pressure balance and CFD flow field simulation, about 10% to 35% of the flue gas in the main flue 1 can flow through the first bypass flue 5 and the second bypass flue 10.
[0042] It should also be noted that the controller can be a PCB board equipped with a C51 single-chip microcomputer, and temperature sensors can be correspondingly arranged in the first bypass flue 5 and the second bypass flue 10, so that the controller can control the operation of the first electric regulating door 4 and the second electric regulating door through the temperature in the first bypass flue 5 and the second bypass flue 10 detected by the temperature sensors.
[0043] In one embodiment, a third electric adjusting door 8 electrically connected to the controller is provided in the main flue 1, and the two ends of the third electric adjusting door 8 are respectively connected to the first end and the second end of the first bypass flue 5, and the two ends of the third electric adjusting door 8 are respectively connected to the first end and the second end of the second bypass flue 10.
[0044] It can be understood that the third electric regulating door 8 in the main flue 1 can cooperate with the first electric regulating door 4 in the first bypass flue 5 to adjust the flue gas flow rate entering the first bypass flue 5 from the main flue 1, thereby facilitating the adjustment of the flue gas temperature in the first bypass flue 5; the third electric regulating door 8 in the main flue 1 can also cooperate with the second electric regulating door in the second bypass flue 10 to adjust the flue gas flow rate entering the second bypass flue 10 from the main flue 1, thereby facilitating the adjustment of the flue gas temperature in the second bypass flue 10.
[0045] It should be noted that, through thermal calculation, the boiler flue gas temperature fluctuates between 600 and 700°C. Corresponding to the flue gas volume under each load of the boiler, a first electric regulating door 4, a second electric regulating door and a third electric regulating door 8 are respectively provided at the first end of the first bypass flue 5, the first end of the second bypass flue 10 and the main flue 1, so as to control the opening of the first bypass flue 5, the second bypass flue 10 and the main flue 1 at different flue temperatures, and then indirectly control the flue gas flow rate flowing through the molten salt heat exchanger 6 and the thermal oil heat exchanger 9, so as to achieve the requirement of controlling the temperature rise of the molten salt and the thermal oil.
[0046] The interlocking control requirements of the opening of the first electric regulating door 4, the opening of the third electric regulating door 8 and the flue gas temperature of the first bypass flue 5 are as shown in the following table.
[0047] Flue gas temperature (℃) The opening of the first electric door The opening of the third electric door 740 100％ 80％ 710 100％ 100％ 650 80％ 100％ 600 50％ 80％
[0048] The interlocking control requirements of the opening of the second electric regulating door, the opening of the third electric regulating door 8 and the flue gas temperature of the second bypass flue 10 are as shown in the following table.
[0049] Flue gas temperature (℃) Second electric door opening The opening of the third electric door 740 100％ 70％ 710 100％ 100％ 650 80％ 80％ 600 50％ 70％
[0050] In one embodiment, the first end and the second end of the first bypass flue 5 are respectively provided with a first electric shutoff door 3 and a second electric shutoff door 7, and the first electric shutoff door 3 and the second electric shutoff door 7 are both electrically connected to the controller.
[0051] It is understandable that the first electric shut-off door 3 and the second electric shut-off door 7 can respectively close the first end and the second end of the first bypass flue 5 so that the flue gas of the main flue 1 cannot enter the first bypass flue 5, thereby facilitating the molten salt heat exchanger 6 to stop working.
[0052] In one embodiment, a third electric shutoff door 11 and a fourth electric shutoff door are respectively provided at the first end and the second end of the second bypass flue 10 , and the third electric shutoff door 11 and the fourth electric shutoff door are both electrically connected to the controller.
[0053] It is understandable that the third electric shut-off door 11 and the fourth electric shut-off door can respectively close the first end and the second end of the second bypass flue 10 so that the flue gas of the main flue 1 cannot enter the second bypass flue 10, thereby facilitating the stopping of the thermal oil heat exchanger 9.
[0054] In one embodiment, a first expansion joint 2 is disposed at both the first end and the second end of the first bypass flue 5 .
[0055] It can be understood that the first expansion joint 2 can absorb the expansion of the first bypass flue 5 due to heat, so as to prevent the first bypass flue 5 and the main flue 1 from being torn apart.
[0056] In one embodiment, a second expansion joint is disposed at both the first end and the second end of the second bypass flue 10 .
[0057] It can be understood that the second expansion joint can absorb the expansion of the second bypass flue 10 due to heat, so as to prevent the second bypass flue 10 and the main flue 1 from being torn apart.
[0058] In one embodiment, the heat exchange pipe of the molten salt heat exchanger 6 is arranged in a winding manner in the first bypass flue 5 .
[0059] It can be understood that the heat exchange pipe of the molten salt heat exchanger 6 is arranged in a winding manner in the first bypass flue 5 to make the heat exchange surface of the molten salt heat exchanger 6 larger, which is beneficial to improve the heat exchange efficiency of the molten salt heat exchanger 6.
[0060] In one embodiment, the heat exchange pipe of the thermal oil heat exchanger 9 is arranged in a winding manner in the second bypass flue 10 .
[0061] It is understandable that the heat exchange pipe of the thermal oil heat exchanger 9 is arranged in a winding manner in the second bypass flue 10 to make the heat exchange surface of the thermal oil heat exchanger 9 larger, thereby facilitating improving the heat exchange efficiency of the thermal oil heat exchanger 9 .
[0062] In one embodiment, the outer sides of the first bypass flue 5 and the second bypass flue 10 are both provided with a heat insulation layer.
[0063] It can be understood that the thermal insulation layer can reduce heat loss so that the heat can be transferred to the molten salt heat exchanger 6 and the thermal oil heat exchanger 9 as much as possible.
[0064] In one embodiment, the first bypass flue 5 and the second bypass flue 10 are both connected inside the enclosure wall 12 .
[0065] In the description of the present invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "back", "inside", "outside", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.
[0066] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments, and other arrangements may be designed without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the features described in the various dependent claims and herein may be combined in a manner different from that described in the original claims. It may also be understood that the features described in conjunction with the individual embodiments may be used in other described embodiments.
Claims
1. A bypass flue gas heat exchanger, which is arranged on a main flue (1), one end of the main flue (1) is connected to a flue gas output end of a boiler, characterized in that: include: a first bypass flue (5), wherein a first end of the first bypass flue (5) is connected to an end of the main flue (1) close to the boiler, a second end of the first bypass flue (5) is connected to an end of the main flue (1) away from the boiler, a first electric regulating door (4) is provided at the first end of the first bypass flue (5), and a molten salt heat exchanger (6) is provided in the first bypass flue (5); a second bypass flue (10), wherein a first end of the second bypass flue (10) is connected to an end of the main flue (1) close to the boiler, a second end of the second bypass flue (10) is connected to an end of the main flue (1) away from the boiler, a second electric regulating door is provided at the first end of the second bypass flue (10), and a heat transfer oil heat exchanger (9) is provided in the second bypass flue (10); A controller is electrically connected to the first electric regulating door (4) and the second electric regulating door.
2. A bypass flue gas heat exchanger according to claim 1, characterized in that: A third electric regulating door (8) electrically connected to the controller is arranged in the main flue (1), and two ends of the third electric regulating door (8) are respectively connected to the first end and the second end of the first bypass flue (5), and two ends of the third electric regulating door (8) are respectively connected to the first end and the second end of the second bypass flue (10).
3. A bypass flue gas heat exchanger according to claim 1 or 2, characterized in that: A first electric shutoff door (3) and a second electric shutoff door (7) are respectively provided at the first end and the second end of the first bypass flue (5); the first electric shutoff door (3) and the second electric shutoff door (7) are both electrically connected to the controller.
4. A bypass flue gas heat exchanger according to claim 1 or 2, characterized in that: A third electric shutoff door (11) and a fourth electric shutoff door are respectively provided at the first end and the second end of the second bypass flue (10), and the third electric shutoff door (11) and the fourth electric shutoff door are both electrically connected to the controller.
5. The bypass flue gas heat exchanger according to claim 1, characterized in that: A first expansion joint (2) is provided at both the first end and the second end of the first bypass flue (5).
6. The bypass flue gas heat exchanger according to claim 1, characterized in that: A second expansion joint is disposed at both the first end and the second end of the second bypass flue (10).
7. The bypass flue gas heat exchanger according to claim 1, characterized in that: The heat exchange pipe of the molten salt heat exchanger (6) is arranged in a winding manner in the first bypass flue (5).
8. The bypass flue gas heat exchanger according to claim 1, characterized in that: The heat exchange pipe of the thermal oil heat exchanger (9) is arranged in a winding manner in the second bypass flue (10).
9. The bypass flue gas heat exchanger according to claim 1, characterized in that: The outer sides of the first bypass flue (5) and the second bypass flue (10) are both provided with a heat insulation layer.
10. The bypass flue gas heat exchanger according to claim 1, characterized in that: The first bypass flue (5) and the second bypass flue (10) are both connected inside the enclosure wall (12).