Coupled air compressor waste heat regulation and utilization system

Abstract

The coupled air compressor waste heat regulation and utilization system is a technical method to solve the problem of discontinuous operation of air compressors, which leads to the difficulty of waste heat recovery, as well as waste heat recovery of multiple air compressors used in combination. At the same time, the compressed air is auxiliary dehumidified to achieve waste heat recovery of air-cooled, liquid-cooled air compressors and compressed gas tanks. The recovered waste heat is used to prepare hot water for production and life, and winter heating water. The system consists of an air-cooled air compressor room, a liquid-cooled air compressor unit, a cooling tower, a compressed air tank, a water source heat pump, a valve group, a water collection and distribution node, a process controller, and a heat exchanger; each air compressor needs to set the working pressure independently, and the high temperature prepared by the water source heat pump and the air source heat pump is collected through the water collection and distribution node. The high-pressure air taken by the air compressor is collected in the compressed air tank through the gas pipeline for production.

Description

Technical Field

[0001] This invention belongs to the field of waste heat recovery and relates to a waste heat regulation and recovery method for air compressors and compressed air tanks that are air-cooled and liquid-cooled. Background Technology

[0002] Air compressors are commonly used equipment in industrial production, with a wide range of applications. They are often used as power sources for pneumatic tools, conveying goods, opening and closing doors and windows, mixing materials, and painting. Air compressors are electrically driven and generate a significant amount of heat during operation. This heat needs to be cooled by fans, liquid circulation, or other methods to ensure normal operation. The release of this heat represents a serious waste of energy. Large industrial enterprises, to ensure production safety, use air compressors with various heat dissipation methods. They also require filtering and low-temperature dehumidification of the compressed air used in production. Due to production process requirements, the operation of air compressors is intermittent and discontinuous. When the pressure in the pressure tank reaches the set value, the equipment shuts down. This intermittent waste heat cannot be utilized for heating. Summary of the Invention

[0003] This invention addresses the waste heat recovery from discontinuous operation of air compressors and the combined use of multiple air compressors. It also provides auxiliary dehumidification of compressed air, achieving waste heat recovery from air-cooled and liquid-cooled air compressors and compressed air tanks. The recovered waste heat is used to prepare hot water for production and domestic use, as well as heating water in winter.

[0004] This invention is implemented as follows: the system mainly consists of an air-cooled air compressor room (containing an air-cooled air compressor unit, an air source heat pump, and ventilation ducts), a liquid-cooled air compressor unit, a cooling tower, a compressed air tank (containing a tank cavity, cooling pipes, an antifreeze chamber, a drain valve, a water collection box, an air delivery pipe, and an antifreeze pressure gauge), a water source heat pump, valve groups, a water distribution node, a process controller, and a heat exchanger (for oil-cooled or non-aqueous liquid isolation heat exchange). Each air-cooled and liquid-cooled air compressor needs to have its working pressure set independently. The high temperature generated by the water source heat pump and the air source heat pump is collected through the water distribution node, and the high-pressure air generated by the air-cooled and liquid-cooled air compressors is collected into the compressed air tank through the air delivery pipe.

[0005] The compressed air tank includes: a tank cavity, a cooling coil inside an antifreeze chamber, an antifreeze pressure gauge at the top of the antifreeze chamber, a drain valve 1 at the bottom of the compressed air tank, a water collection box connected to the bottom of the drain valve 1, a drain valve 2 at the bottom of the water collection box, and an air supply pipe at the top of the compressed air tank.

[0006] In winter, most of the ventilation ducts in the air-cooled air compressor room are closed to conserve heat. An air source heat pump is used to recover the heat released by the air-cooled air compressor. When the indoor temperature exceeds 40°C in winter, the ventilation ducts are opened appropriately to cool down quickly. When the indoor temperature is below 35°C, most of the ventilation ducts are closed to maintain the indoor temperature. In summer, all ventilation ducts are opened to cool down through natural temperature.

[0007] The compressed air tank is a double-walled tank with an outer antifreeze chamber. The antifreeze chamber contains cooling pipes and is filled with antifreeze. A pressure gauge is installed to monitor the antifreeze pressure. The water source heat pump absorbs the air temperature inside the compressed air tank, lowering it to 7°C, close to its condensation point. This process reduces the heat pump's operating load while recovering compressed air. The condensation point of compressed air is between 2°C and 5°C; absorbing the temperature to 7°C reduces the operating load of the compressed air dehumidifier. When the temperature inside the tank drops below 7°C, the valve assembly of the compressed air tank is shut off to prevent a decrease in the water source heat pump's operating efficiency.

[0008] The antifreeze in the antifreeze chamber of the compressed air tank is at atmospheric pressure. Therefore, the water pressure is lower than the pressure of the compressed air in the compressed air tank, so there will be no leakage problem. If the tank is ruptured, the compressed air will ensure that the antifreeze does not flow into the tank chamber.

[0009] The air-cooled and liquid-cooled air compressors are grouped into sets of two, with working pressures set as follows: the first group of air-cooled and liquid-cooled air compressors is 0.5MPa-0.6MPa, the second group is 0.6MPa-0.7MPa, and the third group is 0.7MPa-0.9MPa. This allows the air compressors to operate continuously according to the pressure inside the compressed air tank, preventing shutdowns due to the compressed air tank becoming full and ensuring stable operation of the waste heat recovery equipment.

[0010] When the process controller detects that a high-air-consumption process is about to be carried out, it sends a signal to the air-cooled air compressor and the liquid-cooled air compressor in advance to release the pressure limit and run at full load. Before the high-air-consumption process ends, the pressure limit of the air-cooled air compressor and the liquid-cooled air compressor is restored in advance to avoid the air compressor running at full load and filling the compressed air tank, which would cause the air compressor to stop.

[0011] The heat source of the water source heat pump is the cooling circulating fluid of the liquid-cooled air compressor and the compressed air tank. After being collected by the water collection node, the waste heat is recovered and used as the source water supply. The cooled source return water is sent back to the compressed air tank and the liquid-cooled air compressor through the water distribution node. The high-temperature supply water and the hot water produced by the air source heat pump are collected by the water collection node for heating. The return water after heating is returned to the air source heat pump and the water source heat pump through the water distribution node to be heated again, completing the cycle.

[0012] When a high-air-consumption process starts, the temperature of the water source heat pump recovery is increased. When the waste heat is too large, the operating power of the air source heat pump is reduced and the ventilation duct is opened to naturally dissipate heat for the air-cooled air compressor.

[0013] The beneficial effects of this invention are:

[0014] 1. Adjusting the working pressure of air-cooled and liquid-cooled air compressors under different conditions can reduce the possibility of air compressor shutdown.

[0015] 2. By monitoring the production process, insufficient air pressure and volume can be effectively avoided. At the same time, when high air-consuming processes are stopped, the air compressor pressure control can be restored in advance to extend the air compressor running time, serving as a second means to prevent air compressor shutdown. Attached Figure Description

[0016] Figure 1 Examples of the structure of the present invention Figure 1 .

[0017] Figure 2 Examples of the structure of the present invention Figure 2 .

[0018] As shown: 1. Air-cooled air compressor room (1-1. Exterior wall of the room, 1-2. Ventilation duct, 1-3. Air-cooled air compressor 1, 1-4. Air-cooled air compressor 2, 1-5. Air-cooled air compressor 3, 1-6. Air source heat pump), 2. Liquid-cooled air compressor unit (2-1. Liquid-cooled air compressor 1, 2-2. Liquid-cooled air compressor 2, 2-3. Liquid-cooled air compressor 3), 3. Cooling tower, 4. Compressed air tank (4-1. Tank cavity, 4-2. Cooling pipe, 4-3. Antifreeze chamber, 4-4. Drain valve 1, 4-5. Water collection box, 4-6. Drainage) 1. Valve 2, 4-7. Gas supply pipe, 4-8. Antifreeze pressure gauge, 5. Water source heat pump, 6. Pump 1, 7. Pump 2, 8. Valve group 1, 9. Valve group 2, 10. Valve group 3, 11. Valve group 4, 12. Gas collection pipe, 13. Water collection node 1, 14. Water distribution node 1, 15. Water collection node 2, 16. Water distribution node 2, 17. Process controller, 18. Source return water, 19. Source supply water, 20. Hot water supply 1, 21. Hot water return water 1, 22. Hot water supply 2, 23. Hot water return water 2, 24. Pump 3, 25. Heat exchanger. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Example 1.

[0021] like Figure 1 As shown:

[0022] Ventilation ducts (1-2) are installed on the outer wall (1-1) of the air-cooled air compressor room (1) to adjust the room temperature and intake air. Inside, air-cooled air compressor 1 (1-3) with working pressure 0.5MPa-0.6MPa, air-cooled air compressor 2 (1-4) with working pressure 0.6MPa-0.7MPa, and air-cooled air compressor 3 (1-5) with working pressure 0.7MPa-0.9MPa are installed. An air source heat pump (1-6) is used to indirectly recover the waste heat of the air-cooled air compressor unit.

[0023] The liquid-cooled air compressor unit (2) includes a liquid-cooled air compressor (2-1) with a working pressure of 0.5MPa-0.6MPa, a liquid-cooled air compressor 2 (2-2) with a working pressure of 0.6MPa-0.7MPa, and a liquid-cooled air compressor 3 (2-3) with a working pressure of 0.7MPa-0.9MPa. The cooling tower (3) is used to dissipate heat from the liquid-cooled air compressor unit (2) in summer.

[0024] The compressed air tank (4) is used to store the compressed air produced by the air-cooled air compressor unit and the liquid-cooled air compressor unit (2). It is collected through the air collection pipe (12). The outer shell of the compressed air tank (4) is double-layered, forming an antifreeze chamber (4-3). Antifreeze is injected into the chamber. Cooling pipe (4-2) is coiled inside the antifreeze chamber (4-3). At the same time, an antifreeze pressure gauge (4-8) is installed in the antifreeze chamber (4-3). Drain valve 1 (4-4), water collection box (4-5), and drain valve 2 (4-6) are installed at the bottom of the tank cavity (4-1). When draining, first open drain valve 1 (4-4) to let the water in the tank cavity (4-1) flow into the water collection box (4-5). After the water collection box (4-5) has collected all the water in the tank, close drain valve 1 (4-4) and open drain valve 2 (4-6) to drain the water in the compressed air tank (4).

[0025] The heat source of the water source heat pump (5) is the cooling circulating fluid of the liquid-cooled air compressor (2) and the compressed air tank (4). It is circulated by pump (6) and collected through water collection node 1 (13) to recover waste heat as source water supply (19). The cooled source return water (18) is sent back to the compressed air tank (4) and the liquid-cooled air compressor (2) through water distribution node 1 (14). The hot water supply 1 (20) prepared by the water source heat pump (5) and the hot water supply 2 (22) prepared by the air source heat pump (1-6) are circulated by pump 2 (7) and collected through water collection node 2 (15) for heating. The return water after heating is returned to the air source heat pump (1-6) and the water source heat pump (5) through the hot water return water 2 (23) and hot water return water 1 (21) of water distribution node 2 (16) to be heated again and complete the cycle.

[0026] Valve group 1 (8) is used to control the flow rate of air source heat pump (1-6). When the water source heat pump (5) recovers sufficient waste heat, the flow rate of air source heat pump (1-6) is reduced. Valve group 2 (9) is used to shut down cooling tower (3) in winter so that coolant circulates to water source heat pump (5). Valve group 3 (10) is used to shut down the low temperature heat source circulation of water source heat pump (5). Valve group 4 (11) is used to adjust the waste heat recovery temperature of compressed air tank (4).

[0027] Example 2.

[0028] like Figure 2 As shown:

[0029] Ventilation ducts (1-2) are installed on the outer wall (1-1) of the air-cooled air compressor room (1) to adjust the room temperature and intake air. Inside, air-cooled air compressor 1 (1-3) with working pressure 0.5MPa-0.6MPa, air-cooled air compressor 2 (1-4) with working pressure 0.6MPa-0.7MPa, and air-cooled air compressor 3 (1-5) with working pressure 0.7MPa-0.9MPa are installed. An air source heat pump (1-6) is used to indirectly recover the waste heat of the air-cooled air compressor unit.

[0030] The liquid-cooled air compressor unit (2) includes a liquid-cooled air compressor (2-1) with a working pressure of 0.5MPa-0.6MPa, a liquid-cooled air compressor 2 (2-2) with a working pressure of 0.6MPa-0.7MPa, and a liquid-cooled air compressor 3 (2-3) with a working pressure of 0.7MPa-0.9MPa. The cooling tower (3) is used to dissipate heat from the liquid-cooled air compressor unit (2) in summer.

[0031] The compressed air tank (4) is used to store the compressed air produced by the air-cooled air compressor unit and the liquid-cooled air compressor unit (2). It is collected through the air collection pipe (12). The outer shell of the compressed air tank (4) is double-layered, forming an antifreeze chamber (4-3). Antifreeze is injected into the chamber. Cooling pipe (4-2) is coiled inside the antifreeze chamber (4-3). At the same time, an antifreeze pressure gauge (4-8) is installed in the antifreeze chamber (4-3). Drain valve 1 (4-4), water collection box (4-5), and drain valve 2 (4-6) are installed at the bottom of the tank cavity (4-1). When draining, first open drain valve 1 (4-4) to let the water in the tank cavity (4-1) flow into the water collection box (4-5). After the water collection box (4-5) has collected all the water in the tank, close drain valve 1 (4-4) and open drain valve 2 (4-6) to drain the water in the compressed air tank (4).

[0032] The heat exchanger (25) is used to isolate the liquid-cooled air compressor unit (2) from oil or other cooling media, and to circulate the media using a pump (6).

[0033] The heat source of the water source heat pump (5) is the cooling circulating fluid of the heat exchanger (25) and the compressed air tank (4). It is circulated by pump (24) and collected through water collection node 1 (13) to recover waste heat as source water supply (19). The cooled source return water (18) is sent back to the heat exchanger (25) and the liquid-cooled air compressor (2) through water distribution node 1 (14). The hot water supply 1 (20) prepared by the water source heat pump (5) and the hot water supply 2 (22) prepared by the air source heat pump (1-6) are circulated by pump 2 (7) and collected through water collection node 2 (15) for heating. The return water after heating is returned to the air source heat pump (1-6) and the water source heat pump (5) through the hot water return water 2 (23) and hot water return water 1 (21) of water distribution node 2 (16) to be heated again and complete the cycle.

[0034] Valve group 1 (8) is used to control the flow rate of air source heat pump (1-6). When the water source heat pump (5) recovers sufficient waste heat, the flow rate of air source heat pump (1-6) is reduced. Valve group 2 (9) is used to shut down cooling tower (3) in winter so that coolant circulates to water source heat pump (5). Valve group 3 (10) is used to shut down the low temperature heat source circulation of water source heat pump (5). Valve group 4 (11) is used to adjust the waste heat recovery temperature of compressed air tank (4).

[0035] This invention is not limited to this embodiment. Any equivalent concept or modification within the technical scope disclosed in this invention shall be included within the protection scope of this invention.

Claims

1. A coupled air compressor waste heat regulation and utilization system, characterized in that: The invention comprises an air-cooled compressor room (1), a liquid-cooled compressor unit (2), a cooling tower (3), a compressed air tank (4), a water source heat pump (5), a valve group, a water collecting and distributing node, a process controller (17), and a heat exchanger (25); the air-cooled compressor room (1) and the liquid-cooled compressor unit (2) are connected in parallel and are connected to the compressed air tank (4); the liquid-cooled compressor unit (2) is connected to the heat exchanger (25), and the heat exchanger (25) is connected to the cooling tower (3) and the valve group 3 (10) respectively through the valve group 2 (9). Connected to a water source heat pump (5); the compressed air tank (4) is connected to a process controller (17); the compressed air tank (4) is connected to the water source heat pump (5) through a valve group 3 (10) and a heat exchanger (25); each air-cooled air compressor and liquid-cooled air compressor need to set a working pressure independently; the high temperature generated by the water source heat pump (5) and the air source heat pump (1-6) is collected through a water collecting and distributing node; the high pressure air taken by the air-cooled air compressor and the liquid-cooled air compressor is collected into the compressed air tank (4) through an air collecting pipe (12); The air-cooled compressor room comprises: a plurality of ventilation ducts (1-2) are arranged on the outer wall (1-1) of the room; the equipment in the room comprises an air-cooled compressor 1 (1-3), an air-cooled compressor 2 (1-4), an air-cooled compressor 3 (1-5), and an air source heat pump (1-6); the system needs to use at least three air-cooled compressor units and three liquid-cooled compressor units for coupled waste heat regulation and utilization; The compressed air tank (4) at least comprises: a tank cavity (4-1) wherein a cooling pipe (4-2) is coiled in an antifreeze liquid cavity (4-3); an antifreeze liquid pressure gauge (4-8) is arranged at the top of the antifreeze liquid cavity (4-3); a drain valve 1 (4-4) is arranged at the bottom of the compressed air tank (4); the bottom of the drain valve 1 (4-4) is connected to a water collecting box (4-5); a drain valve 2 (4-6) is arranged at the bottom of the water collecting box (4-5); and an air delivery pipe (4-7) is arranged at the top of the compressed air tank (4); The antifreeze pressure gauge (4-8) is used to observe the antifreeze pressure. The water source heat pump (5) absorbs the air temperature in the compressed air tank (4) to reduce its temperature to 7°C, making it close to the condensation point. While recycling the compressed air, the operating load of the water source heat pump (5) is reduced. The condensation point of compressed air is 2°C-5°C. The temperature is absorbed to 7°C, which reduces the operating load of the compressed air dehumidifier. When the temperature in the air tank is lower than 7°C, the valve group 4 (11) of the compressed air tank (4) is cut off to avoid a reduction in the operating efficiency of the water source heat pump (5).

2. According to claim 1, the coupled air compressor waste heat regulation and utilization system is characterized in that: Two air-cooled air compressors and two liquid-cooled air compressors form a group, and the working pressures of the first group of air-cooled air compressors and liquid-cooled air compressors are set to 0.5MPa-0.6MPa, the second group of air-cooled air compressors and liquid-cooled air compressors are set to 0.6MPa-0.7MPa, and the third group of air-cooled air compressors and liquid-cooled air compressors are set to 0.7MPa-0.9MPa, so that the air compressors can work step by step according to the pressure in the compressed air tank (4) and operate continuously, avoiding shutdown due to full air in the compressed air tank (4), and ensuring stable operation of the waste heat recovery equipment.

3. The coupled air compressor waste heat regulation and utilization system according to claim 1, characterized in that: When monitoring that a high-gas-consuming process is to be carried out, the process controller (17) sends a signal to the air-cooled air compressor and the liquid-cooled air compressor in advance to release the pressure limit and carry out full-load operation. Before the high-gas-consuming process is completed, the pressure limit of the air-cooled air compressor and the liquid-cooled air compressor is restored in advance to avoid the air compressor running at full load and filling up the compressed air tank (4), causing the air compressor to stop, and the water source heat pump (5) to have no heat available, which affects the preparation of hot water; When a high gas consumption process begins, the recovery temperature of the water source heat pump (5) is increased at the same time. When the waste heat is too large, the operating power of the air source heat pump (1-6) is reduced and the ventilation duct (1-2) is opened to naturally dissipate heat for the air-cooled air compressor.

4. The coupled air compressor waste heat regulation and utilization system according to claim 1 is characterized in that: The heat source of the water source heat pump (5) is the cooling circulating fluid of the liquid-cooled air compressor and the compressed air tank. The waste heat is recovered as source water after being collected through the water collection node 1 (13). The source return water after cooling is respectively sent back to the compressed air tank (4) and the liquid-cooled air compressor unit (2) through the water distribution node 1 (14). The high-temperature supply water and the hot water prepared by the air source heat pump (1-6) are collected through the water collection node 2 (15) for heating. The return water after heating is respectively returned to the air source heat pump (1-6) and the water source heat pump (5) through the water distribution node 2 (16) to be heated again to complete the cycle.

5. The coupled air compressor waste heat regulation and utilization system according to claim 1, characterized in that: The antifreeze in the antifreeze chamber (4-3) of the compressed air tank (4) is at normal pressure, so the water pressure is lower than the pressure of the compressed air in the compressed air tank (4), so there will be no leakage problem. When the tank body is ruptured, the compressed air will ensure that the antifreeze will not flow into the tank chamber (4-1).

6. The coupled air compressor waste heat regulation and utilization system according to claim 1, characterized in that: In the air-cooled compressor room (1), most of the ventilation ducts are closed in winter to preserve heat, and the heat released by the air-cooled compressor is recovered by using the air source heat pump (1-6). When the indoor temperature in winter exceeds 40°C, the ventilation ducts (1-2) are opened appropriately to quickly cool down. When the indoor temperature is below 35°C, most of the ventilation ducts are closed to maintain the indoor temperature. In summer, all the ventilation ducts (1-2) are opened to cool down by natural temperature.

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