Energy recovery system and compressor system with same

Abstract

The invention provides an energy recovery system and a compressor system, the energy recovery system comprises a waterway pipeline, the waterway pipeline is provided with a main heat exchanger access port and a standby heat exchanger access port, and the main heat exchanger access port is located at the upstream of the standby heat exchanger access port; the main heat exchanger and / or the user side main heat exchanger are / is connected to the main heat exchanger access port; a standby heat exchanger and / or a user side standby heat exchanger are / is arranged and connected to a standby heat exchanger access port; and the pump assembly is arranged on the waterway pipeline and is positioned at the downstream of the access port of the standby heat exchanger. According to the energy recovery system, a matching scheme without a main heat exchanger and / or a standby heat exchanger can be provided for a client, and more convenient customization is provided for the client.

Description

Technical Field

[0001] The present application relates to the field of energy recovery, and in particular to an energy recovery system and a compressor system having the energy recovery system. Background Art

[0002] Most of the energy recovery systems on the market are designed and modified independently by compressor agents or post-processing suppliers. However, designers often do not understand the performance and control of compressors. As a result, after the compressor is matched with the energy recovery system, the compressor frequently alarms, or the energy recovery system frequently malfunctions. In addition, the energy recovery systems on the market are mainly aimed at recovering the waste heat of all compressors in the entire air compressor room. However, when one or more devices are shut down, the efficiency of the entire system will decrease. At the same time, when customers purchase additional compressors, they cannot be incorporated into the energy recovery system, or the modification cost is very high. In addition, the energy recovery systems currently on the market usually use fixed-frequency control, which is simple to control. When the client application changes, it cannot be adjusted in time, resulting in high system energy consumption, unstable heat exchange and other problems. Summary of the Invention

[0003] To address at least one of the above-mentioned technical problems existing in the prior art, an embodiment of the present application provides an energy recovery system and a compressor system.

[0004] The technical solution adopted in the embodiment of the present application is: an energy recovery system, the energy recovery system comprising:

[0005] A water pipeline, wherein a main heat exchanger access port and a backup heat exchanger access port are provided on the water pipeline, wherein the main heat exchanger access port is located upstream of the backup heat exchanger access port in the direction of water flow in the water pipeline;

[0006] Equipped with a main heat exchanger and / or a user-end main heat exchanger, connected to the main heat exchanger access port;

[0007] Equipped with a spare heat exchanger and / or a user-side spare heat exchanger, connected to the spare heat exchanger access port;

[0008] A pump assembly is provided on the water pipeline and is located downstream of the access port of the standby heat exchanger.

[0009] In an optional embodiment, the pump of the pump assembly is a variable frequency pump; and the water pipeline is provided with a water injection port for supplying circulating water into the water pipeline during the initial commissioning of the energy recovery system.

[0010] In an optional embodiment, a first pressure sensor is provided at the water inlet end of the water pipeline, and a second pressure sensor is provided at the water outlet end of the water pipeline. The first pressure sensor is used to monitor the water inlet pressure at the water inlet end, and the second pressure sensor is used to monitor the water outlet pressure at the water outlet end. The variable frequency pump is used to adjust the speed through variable frequency so that the pressure difference between the water inlet pressure and the water outlet pressure meets the constant condition.

[0011] In an optional embodiment, the pump assembly includes a first pump assembly and a second pump assembly, and either or both of them are arranged in parallel on the water pipeline.

[0012] In an optional embodiment, the first pump assembly and the second pump assembly have the same structure and respectively include a first switch valve, a pump, a one-way valve and a second switch valve which are sequentially arranged along the direction of water flow in the water pipeline.

[0013] In an optional embodiment, the energy recovery system also includes a first temperature sensor, a first temperature control valve and a second temperature sensor which are arranged on the water pipeline in sequence in the direction of water flow; the first temperature sensor is located upstream of the access port of the standby heat exchanger and downstream of the access port of the main heat exchanger, and is used to monitor the first water temperature of the water flow after heat exchange with the equipped main heat exchanger or the user-end main heat exchanger; the second temperature sensor is used to monitor the second water temperature of the water flow coming out of the first temperature control valve; the first temperature control valve is arranged downstream of the access port of the standby heat exchanger, and is used to adjust the flow rate of the water through the equipped standby heat exchanger or the user-end standby heat exchanger based on the first water temperature and the second water temperature, so that the second water temperature meets the constant condition.

[0014] In an optional embodiment, the energy recovery system further comprises an expansion tank, which is provided on the water pipeline and is located downstream of the standby heat exchanger access port and upstream of the pump assembly; and / or

[0015] A safety valve is provided on the water pipeline between the expansion tank and the pump assembly.

[0016] In an optional embodiment, the energy recovery system also includes a water injection pipeline, one end of the water injection pipeline is connected to the water pipeline, the other end of the water injection pipeline forms a water injection port, a first valve and a second valve are connected in series on the water injection pipeline, and the expansion tank is connected to the water injection pipeline between the first valve and the second valve.

[0017] In an optional embodiment, the energy recovery system further includes an exhaust valve, which is provided on the water pipeline between the first temperature control valve and the second temperature sensor, and is used to discharge tiny bubbles in the water of the water pipeline during debugging operation.

[0018] A compressor system includes a compressor unit and an energy recovery system according to any of the above embodiments, wherein the energy recovery system is connected to the water cooling system of the compressor unit, one end of the water pipeline is connected to the water outlet end of the water cooling pipeline of the water cooling system to form a water inlet end, and the other end of the water pipeline is connected to the water inlet end of the water cooling pipeline to form a water outlet end, which is used to recover the waste heat of the compressor unit.

[0019] In an optional embodiment, the compressor unit includes multiple compressors, and the multiple compressors are connected in parallel.

[0020] In an optional embodiment, the compressor unit includes a compressor, and the energy recovery system is arranged in the compressor.

[0021] In an optional embodiment, the water cooling system includes a water cooling pipeline, and the water cooling pipeline passes through at least one of the oil cooler, the intercooler and the aftercooler of the compressor; and / or

[0022] When the motor and / or the head of the compressor are water-cooled, the water-cooling pipeline is also used to pass through the motor and / or the head.

[0023] In an optional embodiment, the water cooling system also includes a third temperature sensor, a flow meter, a fourth temperature sensor and a second temperature control valve; the third temperature sensor is arranged at the water inlet end of the water cooling pipeline, for monitoring the inlet temperature of the water cooling system entering the compressor; the flow meter is arranged on the water cooling pipeline between the third temperature sensor and the oil cooler, for monitoring the water flow; the fourth temperature sensor is arranged on the water cooling pipeline between the second temperature control valve and the aftercooling cooler, for monitoring the outlet water temperature of the water cooling system of the compressor; the second temperature control valve is arranged at the water outlet end of the water cooling pipeline, for adjusting the water flow by changing its own opening so that the outlet water temperature meets the constant condition.

[0024] Compared with the prior art, the beneficial effects of the embodiments of the present application include: the energy recovery system of the present application can provide customers with the option of no main heat exchanger and / or no backup heat exchanger, providing customers with more convenient customization and significantly reducing costs. It optimizes the water flow, achieves more heat recovery while ensuring compressor performance, and reduces the failure rate of the entire system, with low cost and high energy efficiency. Through variable frequency pressure differential control, it can adapt to changes in customer needs, achieve precise control, and accurately calculate recovered heat.

[0025] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention.

[0026] This application describes an overview of various implementations or examples of the technology, and is not a comprehensive disclosure of the full scope or all of the features of the disclosed technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In the drawings, which are not necessarily drawn to scale, like reference numerals may describe similar components in different views. The drawings illustrate various embodiments generally by way of example and not limitation, and together with the description and claims, serve to illustrate the disclosed embodiments. Where appropriate, like reference numerals are used throughout the drawings to refer to like or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive of the embodiments of the present apparatus or method.

[0028] Figure 1 This is a schematic diagram of an energy recovery system according to an embodiment of the present application.

[0029] Figure 2 This is a schematic diagram of an energy recovery system according to another embodiment of the present application.

[0030] Figure 3 Schematic diagram of the three-dimensional structure of the energy recovery system according to an embodiment of the present application.

[0031] Figure 4 for Figure 3 main view.

[0032] Figure 5 for Figure 4 Top view of .

[0033] Figure 6 This is the schematic diagram of the water flow inside the compressor unit.

[0034] Reference numerals:

[0035] 1- Water pipeline; 2- Water inlet; 3- Main heat exchanger; 4- Backup heat exchanger; 5- First pressure sensor; 6- Second pressure sensor; 7- First switch valve; 8- Pump; 9- One-way valve; 10- Second switch valve; 11- First temperature sensor; 12- First temperature control valve; 13- Second temperature sensor; 14- Expansion tank; 15- Safety valve; 16- Water injection pipeline; 17- First valve; 18- Second valve; 19- Exhaust valve; 20- Third switch valve; 21- First port; 22- Second port; 23- Main pipe section; 24- Fourth switch valve; 25-main user water inlet; 26-main user water outlet; 27-tee pipe; 28-standby user water inlet; 29-standby user water outlet; 30-second temperature control valve; 31-third pressure sensor; 32-chassis; 34-water cooling pipeline; 35-third temperature sensor; 36-flow meter; 37-fourth temperature sensor; 38-fifth temperature sensor; 40-oil cooler; 41-motor; 42-high-pressure compressor head; 43-low-pressure compressor head; 44-compensator; 45-intercooler and aftercooler. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] Unless otherwise defined, the technical or scientific terms used in this application should have the usual meanings understood by people with ordinary skills in the field to which this application belongs. The "first", "second" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0038] In order to keep the following description of the embodiments of the present application clear and concise, detailed descriptions of known functions and known components are omitted in this application.

[0039] The embodiment of the present application provides an energy recovery system. Figure 1 and Figure 2 As shown, the energy recovery system includes a water pipeline 1, a main heat exchanger and / or a user-side main heat exchanger, a backup heat exchanger and / or a user-side backup heat exchanger, and a pump assembly. The water pipeline 1 is provided with a main heat exchanger inlet and a backup heat exchanger inlet. The main heat exchanger inlet is located upstream of the backup heat exchanger inlet in terms of water flow within the water pipeline 1. The main heat exchanger and / or the user-side main heat exchanger are connected to the main heat exchanger inlet; the backup heat exchanger and / or the user-side backup heat exchanger are connected to the backup heat exchanger inlet. The pump assembly is located on the water pipeline 1 and downstream of the backup heat exchanger inlet.

[0040] By providing a main heat exchanger access port and a backup heat exchanger access port on the water pipeline 1, the energy recovery system of this application can be configured with a main heat exchanger and / or backup heat exchanger according to the user's needs, or can provide the user with an option of no main heat exchanger and / or no backup heat exchanger, providing users with more convenient customization to meet changing user needs. If the energy recovery system does not have a main heat exchanger and / or backup heat exchanger configured, the user can install them separately, thereby increasing design flexibility and reducing costs.

[0041] It is understood that the so-called equipped main heat exchanger refers to the main heat exchanger equipped with the energy recovery system itself, and the user-side main heat exchanger refers to the user's own main heat exchanger; the equipped standby heat exchanger refers to the standby heat exchanger equipped with the energy recovery system itself, and the user-side standby heat exchanger refers to the user's own standby heat exchanger. For the convenience of the following description, the equipped main heat exchanger and the user-side main heat exchanger are collectively referred to as the main heat exchanger 3, and the equipped standby heat exchanger and the user-side standby heat exchanger are collectively referred to as the standby heat exchanger 4. The model specifications, heat exchange area, and heat exchange efficiency of the main heat exchanger 3 and the standby heat exchanger 4 can be the same or different. This application does not make specific restrictions on this, and they are selected according to the structure of the user's compressor unit.

[0042] in, Figure 1 The figure shows a situation where neither the equipped main heat exchanger nor the user-end main heat exchanger is connected to the main heat exchanger access port, and only the water inlet pipe connected to the first inlet end of the main heat exchanger 3 and the return water pipe connected to the first outlet section of the main heat exchanger 3 are shown. Figure 2 , which shows the situation where the main heat exchanger 3 is connected to the main heat exchanger inlet.

[0043] like Figure 1 and Figure 2 As shown, the main heat exchanger inlet includes a first port 21 and a second port 22 opposite to the first port 21. Figure 2 As shown, the first inlet of the main heat exchanger 3 is detachably connected to the first port 21, and the first outlet of the main heat exchanger 3 is detachably connected to the second port 22, allowing the main heat exchanger 3 to be connected to or removed from the system as needed. Third on / off valves 20 can also be provided at the first inlet and outlet of the main heat exchanger 3 to control whether water in the water pipeline 1 flows through the main heat exchanger 3 for heat exchange. The second inlet and outlet of the main heat exchanger 3 are connected to the user, forming the main heat exchanger user water inlet 25 and main heat exchanger user water outlet 26, respectively.

[0044] Continue to combine Figure 1 and Figure 2In some embodiments, a main pipe section 23 may be provided between the first port 21 and the second port 22 of the main heat exchanger inlet. A fourth on-off valve 24 is connected in series to the main pipe section 23. During normal system operation, both third on-off valves 20 are open, while the fourth on-off valve 24 is closed. High-temperature water from the compressor unit in the water pipeline 1 flows through the main heat exchanger 3 for heat exchange. If the main heat exchanger 3 malfunctions or requires maintenance, the operator can close the two third on-off valves 20 and open the fourth on-off valve 24 to ensure normal system operation. Both the third on-off valve 20 and the fourth on-off valve 24 can be manual or automatic valves, which are not specifically limited in this application.

[0045] The structure of the standby heat exchanger access port may be the same as or different from that of the main heat exchanger access port. Figure 3 As shown, the hot fluid side of the standby heat exchanger 4 is connected in series to the water pipeline 1 through a tee pipe 27, and the inlet and outlet ends of the cold fluid side of the standby heat exchanger 4 are connected to the user, forming a standby user water inlet end 28 and a standby user water outlet end 29 respectively.

[0046] In some embodiments, the pump 8 of the pump assembly is a variable frequency pump; a water injection port is provided on the water pipeline 1 for supplying circulating water into the water pipeline 1 during the initial debugging of the energy recovery system. The present application sets the pump 8 as a variable frequency pump, and performs pressure difference control through the variable frequency speed regulation of the variable frequency pump, which not only has the advantage of energy saving, but also enables the water pressure in the water pipeline 1 to remain stable, and the energy recovery system to operate in a stable pressure state. Since the energy recovery system operates stably and at a stable pressure and will not discharge water due to pressure changes, it only needs to add water once during the initial debugging of the startup, and there is no need for secondary water replenishment (or frequent water replenishment) during operation. The water replenishment port can be eliminated and only one water injection port is provided, which simplifies the structure and is easier to operate, thereby improving the user experience.

[0047] For example, Figure 1 As shown, a first pressure sensor 5 is provided at the water inlet of water line 1, and a second pressure sensor 6 is provided at the water outlet of water line 1. The first pressure sensor 5 is used to monitor the water inlet pressure at the water inlet, and the second pressure sensor 6 is used to monitor the water outlet pressure at the water outlet. The variable frequency pump is used to adjust the speed through variable frequency so that the pressure difference between the water inlet pressure and the water outlet pressure remains constant. When the user application changes, the variable frequency pressure differential control of the variable frequency pump can timely adjust the water flow rate and flow rate to adapt to changing user needs and achieve precise control. At the same time, it matches the control system of the compressor unit to accurately calculate heat recovery, ensuring low energy consumption and stable heat exchange of the system.

[0048] The so-called pressure difference meeting the constant condition means that the pressure difference between the water inlet pressure and the water outlet pressure is basically maintained at a preset pressure. Optionally, the pressure may fluctuate within an allowable range relative to the preset pressure.

[0049] When the energy recovery system is running, the pressure difference between the water inlet pressure and the water outlet pressure monitored by the first pressure sensor 5 and the second pressure sensor 6 is compared with the pressure difference preset by the system. When the pressure difference monitored by the first pressure sensor 5 and the second pressure sensor 6 is lower than the preset pressure difference, the pump 8 accelerates to maintain the pressure difference. When the pressure difference monitored by the two sensors is higher than the preset pressure difference, the pump 8 slows down to maintain the pressure difference. The two pressure sensors can be connected to a controller respectively, which receives the pressure values monitored by the first pressure sensor 5 and the second pressure sensor 6 respectively, calculates and compares them with the pressure difference set by the system, and then controls the speed of the pump 8 according to the comparison result to maintain a basically constant pressure state in the water pipeline 1.

[0050] In an optional embodiment, the pump assembly includes a first pump assembly and a second pump assembly, either or both of which are arranged in parallel on the water pipeline 1. That is, the energy recovery system can provide only one set of pump assemblies or two sets of pump assemblies. When two sets of pump assemblies are provided, the two sets of pump assemblies are arranged in parallel on the water pipeline 1. Figure 1 It shows the situation where two groups of pump assemblies are arranged in parallel on the water pipeline 1. Figure 2 The diagram shows a single pump assembly connected directly to water line 1. The option of a single or dual pump assembly allows for more convenient customization to meet changing user needs. The dual pump option ensures uninterrupted operation of the entire system.

[0051] In an optional embodiment, continue to combine Figure 1 The first and second pump assemblies are each provided with a valve assembly, sequentially arranged along the direction of water flow within waterline 1, comprising a first on-off valve 7, a pump 8, a one-way valve 9, and a second on-off valve 10. This valve assembly has a rational structure, and by placing on-off valves before and after pump 8, it can be used for switching pumps and facilitates maintenance. The structures of the two on-off valves can be identical or different; for example, both on-off valves can be manual ball valves.

[0052] The first pump assembly and the second pump assembly may further include a one-way valve 9, respectively. The one-way valve 9 is located downstream of the pump 8. Figure 1 As shown, in an optional embodiment, a one-way valve 9 is provided between the pump 8 and the second switch valve 10. By providing the one-way valve 9, water from the compressor unit end can be prevented from flowing back to the pump 8, thereby protecting the operation of the pump 8.

[0053] In an optional embodiment, if Figure 1As shown, the energy recovery system also includes a first temperature sensor 11, a first temperature control valve 12, and a second temperature sensor 13, which are sequentially arranged on the water pipeline 1 in the direction of water flow. The first temperature sensor 11 is located upstream of the backup heat exchanger inlet and downstream of the main heat exchanger inlet, and is used to monitor the first water temperature of the water flowing after heat exchange with the main heat exchanger 3. The second temperature sensor 13 is used to monitor the second water temperature of the water flowing out of the first temperature control valve 12. The first temperature control valve 12 is located downstream of the backup heat exchanger inlet and is used to adjust the flow rate of water through the backup heat exchanger 4 based on the first and second water temperatures to ensure that the second water temperature meets the constant condition. The first temperature control valve 12 realizes the series-parallel connection of the main heat exchanger 3 and the backup heat exchanger 4.

[0054] The so-called second water temperature meeting the constant condition means that the second water temperature at the downstream of the standby heat exchanger 4 monitored by the second temperature sensor 13 is maintained at the outlet water temperature preset by the user, and can fluctuate within an allowable range relative to the outlet water temperature set by the user.

[0055] The temperature of the hot water coming out of the compressor unit drops after heat exchange with the main heat exchanger 3, and its temperature is monitored by the first temperature sensor 11. If the first water temperature monitored by the first temperature sensor 11 is lower than the outlet water temperature preset by the user, the water flow in the water pipeline 1 will bypass the standby heat exchanger 4 and flow directly downstream through the first temperature control valve 12; if the first water temperature is higher than the outlet water temperature set by the user, the water flow in the water pipeline 1 will be divided into two paths. The first path goes through the standby heat exchanger 4 to continue to cool down through heat exchange with the standby heat exchanger 4, and the second path goes through the first temperature control valve 12 and merges with the first path at the first temperature control valve 12. The flow rate flowing through the standby heat exchanger 4 (the ratio of the two flow rates) is controlled by the first temperature control valve 12 to achieve the purpose of controlling the outlet water temperature at the second temperature sensor 13 to remain constant.

[0056] For example, when the compressor unit's gas consumption decreases, the heat generated and the heat exchange power decrease. The opening of first thermostatic valve 12 is reduced to maintain the same outlet water temperature. As the system pressure differential increases, pump 8 will slow down to maintain the system pressure differential. The outlet water temperature is monitored by second temperature sensor 13, and the opening of first thermostatic valve 12 is controlled to maintain a constant water temperature, ensuring long-term stable operation of the entire system.

[0057] The energy recovery system of the present embodiment accurately calculates a heat recovery value by monitoring the first and second water temperatures and adjusting the speed of the variable frequency pump. This energy recovery value can be transmitted to a display device, such as a screen, for display, achieving a visual effect. The calculation of the heat recovery value and how it is transmitted and displayed on the screen are prior art and will not be further described here.

[0058] In some embodiments, as Figure 1 、 Figure 2 、 Figure 3 and Figure 5 As shown, the energy recovery system also includes an expansion tank 14, which is installed on the water pipeline 1, downstream of the backup heat exchanger inlet and upstream of the pump assembly. The expansion tank 14 can buffer pressure fluctuations in the water pipeline 1, ensuring that the pressure before entering the pump 8 remains constant, thereby protecting the pump 8.

[0059] Since the water pipeline 1 of the energy recovery system of the present application can maintain a stable pressure state, under normal circumstances, the problem of overpressure will not occur. However, in order to improve the safety performance of the system, a safety valve 15 is further provided on the water pipeline 1 between the expansion tank 14 and the pump assembly. The safety valve 15 is arranged near the pump 8 and the expansion tank 14. When the water pipeline 1 is over-pressured under abnormal circumstances, the safety valve 15 will open to protect the expansion tank 14 and the pump 8. However, since the system operates stably and at a stable pressure, the safety valve 15 will generally not be opened to drain water.

[0060] In some embodiments, the energy recovery system further includes a water injection line 16, one end of which is connected to the water pipeline 1, and the other end of which forms a water inlet. A first valve 17 and a second valve 18 are connected in series to the water injection line 16, and the expansion tank 14 is connected to the water injection line 16 between the first valve 17 and the second valve 18. This layout is rational, compact, and simplifies the piping.

[0061] Expansion tank 14 is connected to the system via first valve 17. When expansion tank 14 undergoes maintenance or malfunctions, first valve 17 can be closed to ensure normal system operation. During system startup and commissioning, first and second valves 17, 18 are opened to add water to the closed-loop pipeline formed by water line 1 and the compressor unit. When the commissioning pressure is high, water is drained through first and second valves 17, 18 to ensure the system's waterway static pressure remains within the 1-1.5 bar range. Furthermore, first and second valves 17, 18 can be used to drain water during system shutdown.

[0062] like Figure 1 and Figure 2 As shown, the energy recovery system also includes an exhaust valve 19, which is provided on the water pipeline 1 between the first temperature control valve 12 and the second temperature sensor 13. The exhaust valve 19 is used to discharge tiny bubbles in the water of the water pipeline 1 during commissioning operation, prevent corrosion of the system and ensure pressure stability. Figure 3 As shown, the exhaust valve 19 can be set at the highest point of the water pipeline 1 of the system to ensure the exhaust effect.

[0063] like Figures 3 and 4 As shown, all components of the energy recovery system of the embodiment of the present application can be installed on the chassis 32 for easy transportation. Box panels can be set around and on the top of the chassis 32 to form a box structure to protect the entire system.

[0064] The following combination Figure 1 The working process of the energy recovery system in one embodiment is described below:

[0065] The hot water from the compressor unit enters the water inlet end 2 of the water pipeline 1, the first pressure sensor 5 monitors the water inlet pressure, and the fifth temperature sensor 38 monitors the water inlet temperature. The hot water then passes through the main heat exchanger 3 for heat exchange. After heat exchange through the main heat exchanger 3, the first water temperature is monitored by the first temperature sensor 11. If the first water temperature is lower than the outlet water temperature set by the user, the water coming out of the main heat exchanger 3 will bypass the standby heat exchanger 4 (that is, it will not flow through the standby heat exchanger 4) and flow directly downstream through the first temperature control valve 12; if the first water temperature is higher than the outlet water temperature set by the user, the water coming out of the main heat exchanger 3 will be divided into two paths, the first path goes through the standby heat exchanger 4, and the second path goes through the first temperature control valve 12, and merges with the first path at the first temperature control valve 12. The first temperature control valve 12 adjusts its own opening to control the mixing ratio of the two water paths, thereby achieving the purpose of controlling the outlet water temperature to be constant. After heat exchange and cooling in the main heat exchanger 3 and the backup heat exchanger 4, the water will pass through the exhaust valve 19. The second temperature sensor 13 then monitors the outlet water temperature, and the third pressure sensor 31 monitors the outlet water pressure. The water will then enter the expansion tank 14 to ensure that the pressure before entering the pump 8 remains constant, protecting the pump 8. The water then passes through the safety valve 15. If it is a single pump assembly, the water will finally pass through the pump 8 and then enter the compressor unit after the pressure is monitored by the second pressure sensor 6. If it is a two-pump assembly, the water can pass through one of the two pump assemblies and then enter the compressor unit after the pressure is monitored by the second pressure sensor 6. The other pump 8 in the two pump assemblies is not working, and the first switch valve 7 and the second switch valve 10 on both sides of the inoperative pump 8 are closed. In this way, the water flow is circulated, achieving the purpose of recovering the energy generated by the compressor unit.

[0066] The present application also provides a compressor system comprising a compressor unit and an energy recovery system according to any of the above-described embodiments. The energy recovery system is connected to the compressor unit's water cooling system to recover waste heat from the compressor unit. Because the compressor system includes the energy recovery system according to the present application, it can precisely match the cooling system (water cooling system) of, for example, a water-cooled, oil-free screw air compressor. This allows for greater heat recovery while maintaining compressor performance, thereby reducing overall system failures, achieving low costs, and increasing energy efficiency.

[0067] The compressor unit includes a compressor, and the number of compressors is not limited. For example, the compressor unit may include one or more compressors. The heat recovered by the compressor system of the embodiment of the application can cover compressors with power of 55-900Kw, and the energy recovery system can recover 80%-105% of the heat of the compressor.

[0068] When multiple compressors are included, the multiple compressors are connected in parallel. For example, four water-cooled oil-free screw compressors ZR1, ZR2, ZR3 and ZR4 can be connected in parallel.

[0069] When the compressor unit includes a compressor, an energy recovery system can be built into the compressor to reduce pressure loss. The compressor can be, for example, a ZR water-cooled screw compressor.

[0070] In some embodiments, the water cooling system includes a water cooling line 34 that passes through at least one of the oil cooler 40, the intercooler, and the aftercooler 45 of the compressor for recovering heat in the compressor lubricating oil or gas compression heat.

[0071] In some embodiments, when the motor 41 and the head of the compressor are cooled by water, the water cooling pipeline 34 is also used to pass through the motor 41, the high-pressure compressor head 42 and the low-pressure compressor head 43 to recover the heat generated by the motor 41 and the compression heat generated by the head.

[0072] The water outlet of the water cooling pipeline 34 is connected to the water inlet 2 of the water pipeline 1, so that the high-temperature water that has absorbed the heat of the compressor enters the water pipeline 1. The water outlet of the water pipeline 1 is connected to the water inlet of the water cooling pipeline 34, so that the high-temperature water flows through the water pipeline 1, is cooled by recovering energy, and then returns to the water cooling pipeline 34 to continue absorbing the heat of the compressor. This cycle continues to realize a continuous heat absorption and heat release process.

[0073] It is understandable that Figure 6 The figure shows a schematic diagram of a water-cooling pipeline 34 passing through the interior of a compressor. When the compressor system includes multiple compressors, the compressor system will include multiple water-cooling pipelines 34 with the same number of compressors. The multiple water-cooling pipelines 34 are connected in parallel to form a total water outlet and a total water inlet. The total water outlet is connected to the water inlet 2 of the water pipeline 1 of the energy recovery system, and the total water inlet is connected to the water outlet of the water pipeline 1 of the energy recovery system to form a closed circulation system.

[0074] In some embodiments, continued binding Figure 6 The water cooling system also includes a third temperature sensor 35, a flow meter 36, a fourth temperature sensor 37, and a second temperature control valve 30. The third temperature sensor 35 is located at the water inlet of the water cooling line 34 and is used to monitor the water inlet temperature of the compressor's water cooling system. The flow meter 36 is located on the water cooling line 34 between the third temperature sensor 35 and the oil cooler 40 and is used to monitor the water flow rate. The fourth temperature sensor 37 is located on the water cooling line 34 between the second temperature control valve 30 and the aftercooler and is used to monitor the water outlet temperature of the compressor's water cooling system. The second temperature control valve 30 is located at the water outlet of the water cooling line 34 and is used to adjust the water flow rate by changing its opening to maintain a constant water outlet temperature.

[0075] The compressor primarily controls the outlet water temperature via a second thermostatic valve 30, within a range of 50°C to 90°C. A flow meter 36 within the compressor monitors water flow to facilitate heat recovery calculation. The maximum inlet water temperature at the primary user's inlet 25 can reach 35°C, while the maximum outlet water temperature can reach 80°C. The maximum inlet water temperature at the backup user's inlet 28 can reach 35°C, while the maximum outlet water temperature can reach 50°C.

[0076] For a compressor, its internal water flow is as follows Figure 6 As shown, the cold water comes out from the water outlet of the energy recovery system and enters the water inlet of the water cooling pipeline 34 of the compressor water cooling system. It first passes through the third temperature sensor 35 and then enters the flow meter 36 inside the compressor. The purpose of the third temperature sensor 35 and the flow meter 36 is to monitor the water temperature and water flow respectively. When the water flow is low and the water temperature is high, an alarm is issued in time to protect the compressor. Then it goes to the oil cooler 40 to recover the compressor lubricating oil or the heat generated by the cooling head. Specifically, when the compressor drive is a water-cooled motor, the cooling water will also flow into the motor 41. The cooling water will then directly flow to the cooling cladding of the high-pressure compressor head 42 and the cooling cladding of the low-pressure compressor head 43 to recover part of the compression heat generated by the head; then it will flow to the intercooler and aftercooler 45 to recover the gas compression heat; then it will pass through the fourth temperature sensor 37 and the second temperature control valve 30 in sequence. The fourth temperature sensor 37 is used to monitor the outlet water temperature. The second temperature control valve 30 controls the outlet water temperature through the PLC and adjusts the valve size. Finally, it outputs high-temperature stable hot water to the water inlet of the energy recovery system. The compressor water cooling system of the present application can not only recover the heat generated by the compressed gas, but also recover the heat from the motor 41 and the oil lubrication system, so that the compressor heat recovery can reach 80%-105%.

[0077] Continue to combine Figure 6 The two ends of the water-cooling pipeline 34 (the water inlet and the water outlet) are respectively provided with compensators 44, which are connected to the water outlet and water inlet 2 of the energy recovery system through the compensators 44. The setting of the compensator 44 allows a certain deviation in the horizontal or vertical direction when the pipelines are connected, making the connection of the pipelines more convenient.

[0078] The above description is intended to be illustrative rather than restrictive, and those skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present disclosure. Furthermore, the above examples (or one or more of them) may be used in combination with each other, and it is contemplated that these embodiments may be combined with each other in various combinations or permutations.

Claims

1. An energy recovery system, characterized in that: The energy recovery system comprises: A water pipeline, wherein a main heat exchanger access port and a backup heat exchanger access port are provided on the water pipeline, wherein the main heat exchanger access port is located upstream of the backup heat exchanger access port in the direction of water flow in the water pipeline; Equipped with a main heat exchanger and / or a user-end main heat exchanger, connected to the main heat exchanger access port; Equipped with a spare heat exchanger and / or a user-side spare heat exchanger, connected to the spare heat exchanger access port; A pump assembly is provided on the water pipeline and is located downstream of the access port of the standby heat exchanger.

2. The energy recovery system according to claim 1, characterized in that The pump of the pump assembly is a variable frequency pump; the water pipeline is provided with a water injection port for supplying circulating water into the water pipeline during the initial commissioning of the energy recovery system.

3. The energy recovery system according to claim 2, characterized in that: A first pressure sensor is provided at the water inlet end of the water pipeline, and a second pressure sensor is provided at the water outlet end of the water pipeline. The first pressure sensor is used to monitor the water inlet pressure at the water inlet end, and the second pressure sensor is used to monitor the water outlet pressure at the water outlet end. The variable frequency pump is used to adjust the speed through variable frequency so that the pressure difference between the water inlet pressure and the water outlet pressure meets the constant condition.

4. The energy recovery system according to claim 1, characterized in that: The pump assembly includes a first pump assembly and a second pump assembly, and either one of the first pump assembly and the second pump assembly are arranged in parallel on the water pipeline.

5. The energy recovery system according to claim 4, characterized in that: The first pump assembly and the second pump assembly have the same structure and respectively include a first switch valve, a pump, a one-way valve and a second switch valve which are sequentially arranged along the water flow direction in the water pipeline.

6. The energy recovery system according to claim 1, characterized in that The energy recovery system also includes a first temperature sensor, a first temperature control valve and a second temperature sensor which are arranged on the water pipeline in sequence in the direction of water flow; the first temperature sensor is located upstream of the access port of the standby heat exchanger and downstream of the access port of the main heat exchanger, and is used to monitor the first water temperature of the water flow after heat exchange with the equipped main heat exchanger or the user-end main heat exchanger; the second temperature sensor is used to monitor the second water temperature of the water flow coming out of the first temperature control valve; the first temperature control valve is arranged downstream of the access port of the standby heat exchanger, and is used to adjust the flow rate of the water flowing through the equipped standby heat exchanger or the user-end standby heat exchanger based on the first water temperature and the second water temperature, so that the second water temperature meets the constant condition.

7. The energy recovery system according to claim 1, characterized in that: The main heat exchanger inlet includes a first port and a second port opposite to the first port. A main pipe section can be connected between the first port and the second port, and a switch valve is connected in series to the main pipe section.

8. The energy recovery system according to claim 1, characterized in that: The energy recovery system further comprises an expansion tank, which is provided on the water pipeline and is located downstream of the standby heat exchanger access port and upstream of the pump assembly; and / or A safety valve is provided on the water pipeline between the expansion tank and the pump assembly.

9. The energy recovery system according to claim 8, characterized in that: The energy recovery system also includes a water injection pipeline, one end of which is connected to the water pipeline, and the other end of which forms a water injection port. A first valve and a second valve are connected in series on the water injection pipeline, and the expansion tank is connected to the water injection pipeline between the first valve and the second valve.

10. The energy recovery system according to claim 6, characterized in that: The energy recovery system further includes an exhaust valve, which is provided on the water pipeline between the first temperature control valve and the second temperature sensor and is used to discharge tiny bubbles in the water of the water pipeline during commissioning operation.

11. A compressor system, comprising a compressor unit, characterized in that: It also includes an energy recovery system as described in any one of claims 1 to 10, wherein the energy recovery system is connected to the water cooling system of the compressor unit, one end of the water pipeline is connected to the water outlet end of the water cooling pipeline of the water cooling system to form a water inlet end, and the other end of the water pipeline is connected to the water inlet end of the water cooling pipeline to form a water outlet end, which is used to recover the waste heat of the compressor unit.

12. The compressor system according to claim 11, wherein The compressor unit includes a plurality of compressors, and the plurality of compressors are connected in parallel.

13. The compressor system according to claim 11, wherein: The compressor unit includes a compressor, and the energy recovery system is arranged in the compressor.

14. The compressor system according to claim 11, wherein The water cooling system includes a water cooling line, the water cooling line passing through at least one of the oil cooler, the intercooler housing and the aftercooler housing of the compressor; and / or When the motor and / or the head of the compressor are water-cooled, the water-cooling pipeline is also used to pass through the motor and / or the head.

15. The compressor system according to claim 11, wherein The water cooling system also includes a third temperature sensor, a flow meter, a fourth temperature sensor and a second temperature control valve; the third temperature sensor is arranged at the water inlet end of the water cooling pipeline, for monitoring the inlet water temperature of the water cooling system entering the compressor; the flow meter is arranged on the water cooling pipeline between the third temperature sensor and the oil cooler, for monitoring the water flow; the fourth temperature sensor is arranged on the water cooling pipeline between the second temperature control valve and the aftercooling cooler, for monitoring the outlet water temperature of the water cooling system of the compressor; the second temperature control valve is arranged at the water outlet end of the water cooling pipeline, for adjusting the water flow by changing its own opening so that the outlet water temperature meets the constant condition.

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