Lithium battery negative electrode waste heat utilization system

Abstract

The utility model discloses a lithium battery cathode waste heat utilization system which comprises a cathode coating oven, an ultrapure water tank, an air heat exchanger and an air-water heat exchanger, the air heat exchanger and the air-water heat exchanger are connected between the cathode coating oven and the ultrapure water tank, and air sequentially passes through a fresh air fan and the air heat exchanger through a first gas pipeline to enter an air inlet of the cathode coating oven; an exhaust port of the cathode coating oven is connected with an exhaust fan after passing through the air heat exchanger and the air-water heat exchanger through a second gas pipeline; the tap water inlet pipe is connected with the ultrapure water tank through the first water body pipeline and the gas-water heat exchanger, the ultrapure water tank is connected with the ultrapure water system through the third water body pipeline, and the third water body pipeline is provided with a water inlet pump. According to the utility model, the exhaust heat of the cathode coating oven can be fully utilized to replace the electric heating of the original ultrapure water system, so that the energy consumption is reduced, and the inlet water temperature can be stabilized.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy, in particular to a waste heat recovery system of a negative electrode coating oven in a lithium battery workshop. Background Art

[0002] In lithium battery production, the recycling of high-temperature gas energy generated by negative electrode coating and baking is a common practice in the current industry. However, since the current negative electrode oven baking temperature is generally set at around 120°C, the conventional negative electrode waste heat recovery system still has a residual temperature of 50~60°C after heat exchange with outdoor fresh air, and the pure water evaporated from the system during the baking process is not collected, resulting in energy waste.

[0003] At the same time, ultrapure water is needed to supply negative electrode slurry and battery cleaning sections in lithium battery production. Ultrapure water is prepared using reverse osmosis membrane technology. Generally speaking, the inlet water temperature of the reverse osmosis membrane under working conditions is 25°C. For every 1°C decrease in temperature, the viscosity of the water increases, causing the water production rate of the reverse osmosis membrane to decrease by about 2-3%. Especially in winter, since the inlet water comes from the municipal water supply network and the water temperature is relatively low, in order to ensure the normal water production of the ultrapure water system, an electric heating system is often required. The cost of electric heating is high and there is uneven heating, so the effect is not good. Utility Model Content

[0004] In view of the above technical problems, the utility model proposes a system for utilizing the waste heat of the negative electrode of a lithium battery, which fully utilizes the exhaust heat of the negative electrode coating oven to replace the electric heating of the original ultrapure water system, which not only reduces energy consumption, but also stabilizes the inlet water temperature, improves the system working efficiency, and achieves the purpose of energy saving and consumption reduction.

[0005] In order to achieve the above technical purpose, the utility model adopts the following technical means:

[0006] A lithium battery negative electrode waste heat utilization system, comprising:

[0007] Negative electrode coating oven, ultrapure water tank and the connection between the above two devices:

[0008] Air heat exchanger and air-water heat exchanger, wherein:

[0009] The air introduced from the outside enters the air inlet of the negative electrode coating oven through the first gas pipeline, the fresh air blower, and the air heat exchanger in sequence;

[0010] The exhaust port of the negative electrode coating oven is connected to the exhaust fan through a second gas pipeline after passing through an air heat exchanger and an air-water heat exchanger;

[0011] The tap water inlet pipe from the municipal pipeline is connected to the air-water heat exchanger and the ultrapure water tank through the first water body pipeline. The ultrapure water tank is connected to the ultrapure water system through the third water body pipeline. The third water body pipeline is equipped with an inlet pump.

[0012] It also includes a water inlet regulating valve, whose water inlet is connected to the tap water inlet pipeline, whose first water outlet is connected to the first water body pipeline, and whose second water outlet is connected to the ultrapure water tank via a second water body pipeline;

[0013] A temperature sensor is connected to the third water body pipeline and is located between the ultrapure water tank and the water inlet pump, and is used to detect the temperature of the pipeline water before entering the water inlet pump;

[0014] The controller has a signal input end connected to the temperature sensor and a signal output end interlocked with the water inlet regulating valve.

[0015] The air heat exchanger is connected to the ultrapure water tank via a first condensed water pipeline;

[0016] The air-water heat exchanger is connected to the ultrapure water tank via a second condensed water pipeline.

[0017] A fresh air filter is provided on the first gas pipeline between the fresh air blower and the fresh air inlet.

[0018] At least one or more of a first temperature detector, a first dew point meter, a first anemometer, and a first differential pressure meter are installed on the first gas pipeline between the outdoor fresh air and the cathode coating oven;

[0019] The second gas pipeline connected to the exhaust port of the negative electrode coating oven is installed with at least one or more of a second temperature detector, a second dew point meter and a second differential pressure meter;

[0020] The first water body pipeline connected to the tap water inlet pipe is at least equipped with one or more of a first check valve, a first butterfly valve, a first gate valve, a first flow meter and a first pressure gauge;

[0021] The second water pipeline connected between the water inlet regulating valve and the ultrapure water tank is at least installed with one or more of a second check valve, a second butterfly valve, a second gate valve, a second flow meter and a second pressure gauge.

[0022] At least one or more of a third gate valve, a first vent valve and a third flow meter are installed on the first condensate water pipeline;

[0023] At least one or more of a fourth gate valve, a second vent valve and a fourth flow meter are installed on the second condensate pipeline.

[0024] At least one or more of a third butterfly valve, a third pressure gauge and a fifth flow meter are installed on the water supply pipeline from the water inlet pump to the ultrapure water system.

[0025] The air heat exchanger and the air-water heat exchanger are both plate heat exchangers.

[0026] Beneficial effects:

[0027] Advantages of the utility model:

[0028] (1) The utility model solves the problem of incomplete energy utilization of the exhaust hot air of the negative electrode coating oven in the traditional negative electrode waste heat recovery system by adding an air-water heat exchanger. On the other hand, it realizes the preheating of the inlet water of the ultrapure water system, changes the situation of long time and uneven heating of traditional electric heating, can save energy and reduce consumption, and improve the water production efficiency of the system.

[0029] (2) The utility model increases the inlet water temperature sensor and the regulating valve, controls the water temperature of the pipe before the inlet water pump to 25°C, and can stabilize the inlet water temperature of the ultrapure water system by controlling the opening and closing degree of the regulating valve, thereby preventing the inlet water temperature from changing due to external conditions, and ensuring that the working capacity of the ultrapure water system is always in a high efficiency range.

[0030] (3) The utility model provides a lithium battery negative electrode waste heat utilization system, which recycles the pure water evaporated in the system during the baking process and supplies it to the ultrapure water system, thereby avoiding the waste of pure water.

[0031] (4) The lithium battery negative electrode waste heat utilization system provided by the utility model has a simple structure and is easy to maintain and use on a daily basis; BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of the utility model of the lithium battery negative electrode waste heat utilization system;

[0033] Among them, 1-negative electrode coating oven, 2-fresh air filter, 3-fresh air fan, 4-air heat exchanger, 5-gas-water heat exchanger, 6-exhaust fan, 7-water inlet regulating valve, 8-ultrapure water tank, 9-temperature sensor, 10-water inlet pump, 11-first water body pipeline, 12-second water body pipeline, 13-first gas pipeline, 14-second gas pipeline, 15-third water body pipeline, 16-first condensed water pipeline, 17-second condensed water pipeline. DETAILED DESCRIPTION

[0034] The present invention will be described in detail below in conjunction with the embodiments and drawings. It should be noted that many specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, so the present invention is not limited to the specific implementation disclosed below. Example 1

[0035] like Figure 1 As shown, a lithium battery negative electrode waste heat utilization system proposed by the utility model includes a negative electrode coating oven 1, a fresh air fan 3, an air heat exchanger 4, an air-water heat exchanger 5, an exhaust fan 6, an ultrapure water tank 8, a water inlet pump 10, a first water body pipeline 11, a second water body pipeline 12; a first gas pipeline 13, a second gas pipeline 14, and a third water body pipeline 15;

[0036] The air introduced from the outside passes through the first gas pipeline 13, the fresh air blower 3, the air heat exchanger 4, and then enters the air inlet of the negative electrode coating oven 1;

[0037] The exhaust port of the negative electrode coating oven 1 is connected to the exhaust fan 6 through the second gas pipeline 14, the air heat exchanger 4, the air-water heat exchanger 5;

[0038] The tap water inlet pipe from the municipal pipeline is connected to the ultrapure water tank 8 through the first water body pipeline 11 via the air-water heat exchanger 5. The ultrapure water tank 8 is connected to the ultrapure water system through the third water body pipeline 15. The third water body pipeline 15 is equipped with a water inlet pump 10.

[0039] The negative electrode coating oven 1 described in the embodiment of the utility model can be a double-layer coating machine with an exhaust volume of 70000m 3 / h, the hot air temperature discharged from the air outlet is about 120℃, the heat exchange efficiency of the air heat exchanger 4 is above 60%, the temperature of the fresh air introduced from the outside is 25℃ (5℃ in winter), the air inlet temperature after heat exchange by the air heat exchanger 4 is above 60℃, and the air outlet temperature is 50~60℃.

[0040] The heat exchange efficiency of the air-to-water heat exchanger 5 described in the embodiment of the utility model is above 60%, the exhaust air temperature introduced from the air heat exchanger 4 is around 50-60°C, the inlet water temperature is 25°C (5°C in winter), and the tap water can fully exchange heat with the inlet air of the air-to-water heat exchanger 5 before entering the ultrapure water raw water tank 8.

[0041] As a preferred solution of this embodiment, the negative electrode coating system may include multiple negative electrode coating ovens and multiple heat recovery systems, each negative electrode coating oven is connected to a corresponding heat recovery system. The multiple negative electrode coating ovens are connected as one. Example 2

[0042] The difference between this embodiment and embodiment 1 is that an inlet water temperature sensor and a regulating valve are added, and by controlling the water temperature of the pipeline before the water inlet pump to 25°C, the inlet water temperature of the ultrapure water system can be stabilized by controlling the opening and closing degree of the regulating valve, so as to avoid the inlet water temperature from changing due to external conditions, so that the working capacity of the ultrapure water system is always in a high efficiency range. The specific technical scheme is: it also includes an inlet regulating valve 7, whose water inlet is connected to the tap water inlet pipe, whose first water outlet is connected to the first water body pipeline 11, and whose second water outlet is connected to the ultrapure water tank 8 via the second water body pipeline 12;

[0043] A temperature sensor 9, connected to the third water body pipeline 15 and located between the ultrapure water tank 8 and the water inlet pump 10, for detecting the temperature of the pipeline water before entering the water inlet pump 10;

[0044] The controller has a signal input end connected to the temperature sensor 9 and a signal output end interlocked with the water inlet regulating valve 7 .

[0045] The temperature sensor 9 sets the water temperature in the water inlet pipe before the water inlet pump 10 to 25°C and is interlocked with the regulating valve 7. By controlling the regulating valve 7, the water inlet flow in the first water body pipeline 11 and the second water body pipeline 12 can be distributed, thereby achieving stable and uniform control of the water temperature of the pipeline water before the water inlet pump 10 at around 25°C, without the need for additional electrical heating of the raw water. Example 3

[0046] The difference between this embodiment and Embodiment 1 and Embodiment 2 is that the pure water inside the system evaporated during the baking process is recycled and supplied to the ultrapure water system, thereby avoiding the waste of pure water. The specific technical scheme is: it also includes a first condensed water pipeline 16 and a second condensed water pipeline 17, and the air heat exchanger is connected to the ultrapure water tank through the first condensed water pipeline 16; the air-water heat exchanger is connected to the ultrapure water tank through the second condensed water pipeline 17. The condensed water pipeline is provided with corresponding gate valves, vent valves, flow meters, etc. In theory, the water evaporated by the negative electrode coating oven is only pure water, which can continue to enter the ultrapure water system for treatment and utilization after being collected in the ultrapure water tank, thereby reducing the water consumption of tap water and reducing costs. Example 4

[0047] The difference between this embodiment and the above three embodiments is that a fresh air filter 2 is provided on the gas pipeline between the fresh air blower 3 and the fresh air inlet.

[0048] Furthermore, the fresh air filter 3 includes a primary filter and a medium filter, which is mainly used to purify the fresh air to meet the requirements of the coating machine working environment for incoming air. Example 5

[0049] The difference between this embodiment and the above embodiment is that the air intake and exhaust after heat exchange are monitored and controlled in real time by instruments to achieve the requirements of the coating machine for the air intake temperature and dew point.

[0050] The first gas pipeline 13 between the outdoor fresh air and the cathode coating oven 1 is at least equipped with one or more of a first temperature detector, a first dew point meter, a first anemometer and a first differential pressure meter;

[0051] The second gas pipeline 14 connected to the exhaust port of the negative electrode coating oven 1 is at least equipped with one or more of a second temperature detector, a second dew point meter and a second differential pressure meter;

[0052] The first water pipe 11 connected to the tap water inlet pipe is at least equipped with one or more of a first check valve, a first butterfly valve, a first gate valve, a first flow meter and a first pressure gauge;

[0053] The second water pipeline 12 connected between the water inlet regulating valve and the ultrapure water tank 8 is at least installed with one or more of a second check valve, a second butterfly valve, a second gate valve, a second flow meter and a second pressure gauge.

[0054] The utility model provides a system for utilizing waste heat of negative electrodes of lithium batteries, which also includes a central control device, which can be interlocked with the negative electrode coating oven, fresh air fan, exhaust fan, detection instruments, etc. The central control device can be a PLC controller, etc., which can adopt components known to technical personnel in this field and can be set at corresponding positions according to specific functional requirements.

[0055] Furthermore, as a preferred embodiment of the above-mentioned embodiment of the utility model, a corresponding butterfly valve, a pressure gauge, a flow meter, etc. are provided on the water supply pipeline from the water inlet pump 10 to the ultrapure water system.

[0056] The above is only a preferred specific implementation method of the utility model, and the protection scope of the utility model is not limited to it. Any technician familiar with the technical field within the technical scope disclosed by the utility model can make equivalent replacements or changes based on the technical scheme and utility model concept of the utility model, which should be covered by the protection scope of the utility model.

Claims

1. A lithium battery negative electrode waste heat utilization system, characterized in that: include: Anode coating oven (1), ultrapure water tank (8), and the following connected between the two devices: An air heat exchanger (4) and an air-water heat exchanger (5), wherein: The air introduced from the outside passes through a first gas pipeline (13), passes through a fresh air blower (3), an air heat exchanger (4) in sequence, and then enters the air inlet of the negative electrode coating oven (1); The exhaust port of the negative electrode coating oven (1) is connected to the exhaust fan (6) via a second gas pipeline (14) through an air heat exchanger (4) and an air-water heat exchanger; A tap water inlet pipe from the municipal pipe network is connected to the air-water heat exchanger and the ultrapure water tank (8) via a first water body pipeline (11); the ultrapure water tank is connected to the ultrapure water system via a third water body pipeline (15); and a water inlet pump (10) is installed on the third water body pipeline (15).

2. The lithium battery negative electrode waste heat utilization system according to claim 1, characterized in that: It also comprises a water inlet regulating valve (7), whose water inlet is connected to the tap water inlet pipe, whose first water outlet is connected to the first water body pipeline (11), and whose second water outlet is connected to the ultrapure water tank (8) via a second water body pipeline (12); A temperature sensor connected to the third water body pipeline (15) and located between the ultrapure water tank and the water inlet pump, and used to detect the temperature of the water in the pipeline before entering the water inlet pump; A controller, wherein a signal input end thereof is connected to the temperature sensor, and a signal output end thereof is interlocked with the water inlet regulating valve (7).

3. The lithium battery negative electrode waste heat utilization system according to claim 1, characterized in that: The air heat exchanger (4) is connected to the ultrapure water tank (8) via a first condensed water pipeline (16); The air-water heat exchanger (5) is connected to the ultrapure water tank (8) via a second condensed water pipeline (17).

4. The lithium battery negative electrode waste heat utilization system according to claim 1, characterized in that: A fresh air filter (2) is provided on the first gas pipeline between the fresh air blower (3) and the fresh air inlet.

5. The lithium battery negative electrode waste heat utilization system according to claim 2, characterized in that: The first gas pipeline (13) between the outdoor fresh air and the cathode coating oven (1) is installed with at least one or more of a first temperature detector, a first dew point meter, a first anemometer and a first differential pressure meter; The second gas pipeline (14) connected to the exhaust port of the negative electrode coating oven (1) is at least equipped with one or more of a second temperature detector, a second dew point meter and a second differential pressure meter; The first water pipe (11) connected to the tap water inlet pipe is at least equipped with one or more of a first check valve, a first butterfly valve, a first gate valve, a first flow meter and a first pressure gauge; The second water body pipeline (12) connected between the water inlet regulating valve and the ultrapure water tank (8) is installed with at least one or more of a second check valve, a second butterfly valve, a second gate valve, a second flow meter and a second pressure gauge.

6. The lithium battery negative electrode waste heat utilization system according to claim 3, characterized in that: The first condensate water pipeline (16) is at least equipped with one or more of a third gate valve, a first vent valve and a third flow meter; At least one or more of a fourth gate valve, a second vent valve and a fourth flow meter are installed on the second condensate pipeline (17).

7. The lithium battery negative electrode waste heat utilization system according to claim 1, characterized in that: At least one or more of a third butterfly valve, a third pressure gauge and a fifth flow meter are installed on the water supply pipeline from the water inlet pump (10) to the ultrapure water system.

8. The lithium battery negative electrode waste heat utilization system according to claim 1, characterized in that: The air heat exchanger (4) and the air-water heat exchanger (5) are both plate-type heat exchangers.

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