Cooling system for gas suspension high temperature heat pump and heat pump unit

Abstract

This invention relates to the field of air-suspension high-temperature heat pump technology, and provides a cooling system and heat pump unit for an air-suspension high-temperature heat pump. The cooling system includes: a liquid supply device for providing liquid refrigerant; a first heat exchanger, with chilled water flowing through its auxiliary side; the main inlet of the first heat exchanger connected to the liquid supply device; and the main outlet of the first heat exchanger connected to the inlet of the air-suspension bearing, with the outlet of the air-suspension bearing connected to the inlet of the liquid supply device. In the air-suspension high-temperature heat pump and heat pump unit provided by this invention, the liquid refrigerant flows from the outlet of the liquid supply device through the first heat exchanger. After being cooled by the chilled water in the first heat exchanger, the liquid refrigerant cools the air-suspension high-temperature heat pump. The liquid refrigerant then enters the bearing to support the rotor suspension, subsequently flowing out from the bottom of the compressor and back into the liquid supply device, thereby achieving liquid refrigerant circulation and further cooling of the air-suspension high-temperature heat pump.

Description

Technical Field

[0001] This invention relates to the field of air-suspension high-temperature heat pump technology, and in particular to a cooling system and heat pump unit for air-suspension high-temperature heat pumps. Background Technology

[0002] In industrial high-temperature heat pump units, under condenser temperatures exceeding 100°C and even higher exhaust temperatures, most conventional lubricating oils will rapidly oxidize, decompose, and carbonize. Degraded lubricating oil loses its lubricating properties, leading to wear on bearings and moving parts, and forming an oil film on the heat exchanger surface, severely impacting heat exchange efficiency. Especially when the system temperature rises above 60K, conventional condenser-based throttling cooling methods result in high dryness after throttling, leading to insufficient coolant volume and difficulty in cooling the unit's motor and lubricating oil. Air-suspension heat pumps, however, solve the problem of lubricating oil failure at high temperatures by throttling and spraying the supplied liquid into a two-phase gas-liquid state through micro-orifices in the bearings, thus suspending the rotor, lubricating, and cooling.

[0003] However, in the existing technology, when the temperature of the liquid refrigerant entering the bearing is high, the cooling effect will also be affected under the air-suspended high-temperature heat pump operation. Summary of the Invention

[0004] This invention provides a cooling system and heat pump unit for air-suspended heat pumps, which solves the problem of high liquid refrigerant temperature in high-temperature heat pump bearings in the prior art.

[0005] This invention provides a cooling system for an air-suspended high-temperature heat pump, the air-suspended high-temperature heat pump including a compressor, the compressor having an air-suspended bearing, and the cooling system comprising: Liquid supply device, used to provide liquid refrigerant; The first heat exchanger has a cold source water flowing through its auxiliary side. The main inlet of the first heat exchanger is connected to the liquid supply device, and the main outlet of the first heat exchanger is connected to the inlet of the air suspension bearing. The outlet of the air suspension bearing is also connected to the inlet of the liquid supply device.

[0006] The cooling system for an air-suspended high-temperature heat pump provided by this invention provides liquid refrigerant to the compressor bearing through a liquid supply device. After the liquid refrigerant comes out of the outlet of the liquid supply device, it flows through the first heat exchanger. After the temperature of the cold source water in the first heat exchanger is reduced, it cools the air-suspended bearing. After the liquid refrigerant enters the bearing, it supplies the rotor with suspension and flows out from the bottom of the compressor, and then enters the liquid supply device, thereby realizing the circulation of liquid refrigerant. The air-suspended bearing is cooled by the liquid refrigerant, thereby realizing the cooling of the air-suspended high-temperature heat pump.

[0007] A cooling system for an air-suspended high-temperature heat pump according to the present invention further includes: The second heat exchanger has its main inlet connected to the outlet of the air suspension bearing, and its main outlet connected to the inlet of the liquid supply device.

[0008] With the above structure, after the liquid refrigerant enters the bearing and is suspended by the rotor, it flows out from the bottom of the compressor, passes through the second heat exchanger again, and is cooled by the cold source water in the second heat exchanger before entering the liquid supply device, thereby achieving further cooling of the liquid refrigerant.

[0009] According to the present invention, a cooling system for a high-temperature heat pump with air suspension is provided, wherein the liquid supply device comprises: A liquid storage tank has an outlet for supplying liquid refrigerant, and a gear pump is connected downstream of the outlet. A liquid supply tank is connected downstream of the liquid outlet, and the liquid supply tank is connected to the main inlet of the first heat exchanger.

[0010] With the above structure, the liquid storage tank is used to store liquid refrigerant, and the liquid level in the supply tank is maintained by a gear pump drawing liquid from the liquid storage tank.

[0011] A cooling system for an air-suspended high-temperature heat pump according to the present invention further includes: The motor cooling structure has an inlet connected to the outlet of the gear pump and an outlet connected to the main inlet of the second heat exchanger.

[0012] With the above structure, the liquid refrigerant in the storage tank can be supplied to the motor for cooling after passing through the gear pump. The liquid refrigerant after the motor is cooled, together with the liquid refrigerant used to cool the bearing, returns to the storage tank.

[0013] A cooling system for an air-suspended high-temperature heat pump according to the present invention further includes: The inverter cooling structure has its inlet connected to the outlet of the gear pump and its outlet connected to the inlet of the liquid storage tank.

[0014] With the above structure, the liquid refrigerant in the storage tank can be supplied to the frequency converter for cooling after passing through the gear pump, and the liquid refrigerant after being cooled by the frequency converter returns to the storage tank.

[0015] According to the present invention, a cooling system for an air-suspended high-temperature heat pump is provided, wherein the inlet of the gear pump is connected to the condenser and the evaporator of the air-suspended high-temperature heat pump respectively, and a first valve is provided between the inlet of the gear pump and the condenser, and a second valve is provided between the inlet of the gear pump and the evaporator.

[0016] With the above structural design, the gear pump can also draw liquid from the condenser and evaporator. This is primarily done initially when the liquid level in the storage tank is very low. Once the system is running normally, the liquid level in the storage tank is high enough that two separate pumping points from the condenser and evaporator are no longer needed. When pumping is required, the first and second valves open; when pumping is not required, the first and second valves close.

[0017] According to the present invention, a cooling system for an air-suspended high-temperature heat pump is provided, wherein a first level gauge is provided inside the liquid storage tank, and a bypass valve is provided between the outlet of the gear pump and the evaporator.

[0018] With the above structure, as the compressor runs, the refrigerant level in the receiver tank increases. When the detected level reaches a certain level, the bypass valve of the receiver tank is opened to draw the excess liquid refrigerant back to the evaporator and re-enter the main refrigerant circulation system.

[0019] According to the present invention, a cooling system for an air-suspended high-temperature heat pump is provided, wherein a pressure relief valve is provided between the liquid supply tank and the liquid storage tank.

[0020] With the above structure, a pressure relief valve is installed between the supply tank and the storage tank to prevent excessive pressure differential in the supply of the air suspension bearing.

[0021] According to the present invention, a cooling system for an air-suspended high-temperature heat pump is provided, wherein a filter is further provided between the liquid storage tank and the gear pump.

[0022] With the above structure, the filter can filter the liquid refrigerant flowing out of the storage tank.

[0023] The present invention also provides a heat pump unit, including a cooling system for an air-suspended high-temperature heat pump as described in any of the preceding claims.

[0024] The heat pump unit provided by the present invention has the various advantages described above because it includes the cooling system for air-suspended high-temperature heat pumps as described above. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the cooling system for a high-temperature air-suspended heat pump provided by the present invention; Figure label: 100. Compressor; 200. Condenser; 300. Evaporator; 400. Flash evaporator; 1. First heat exchanger; 2. Second heat exchanger; 3. Liquid storage tank; 4. Gear pump; 5. Liquid supply tank; 6. Motor cooling structure; 7. Inverter cooling structure; 8. First valve; 9. Second valve; 10. Bypass valve; 11. Pressure relief valve; 12. Filter. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0028] The following is combined with Figure 1 The first aspect of the present invention describes a cooling system for an air-suspended high-temperature heat pump, the air-suspended high-temperature heat pump including a compressor 100, wherein an air-suspended bearing is disposed within the compressor 100.

[0029] The cooling system includes a liquid supply device and a first heat exchanger 1. The liquid supply device provides liquid refrigerant, and a dedicated liquid supply device ensures a stable supply of the cooling medium. Cold source water flows through the auxiliary side of the first heat exchanger, providing cooling capacity to the liquid refrigerant on the main side of the first heat exchanger. The main inlet of the first heat exchanger 1 is connected to the outlet of the liquid supply device, and the main outlet of the first heat exchanger 1 is connected to the inlet of the air suspension bearing, and the outlet of the air suspension bearing is connected to the inlet of the liquid supply device.

[0030] The cooling system for a high-temperature air-suspended heat pump provided by this invention supplies liquid refrigerant to the bearing of compressor 100 via a liquid supply device. After exiting the outlet of the liquid supply device, the liquid refrigerant flows through the first heat exchanger 1, where it is cooled by cold water. This lowers the refrigerant temperature, increasing the heat exchange temperature difference with the bearing, ensuring sufficient cooling even under high-temperature and high-load conditions. The cooled liquid refrigerant then enters the air-suspended bearing, directly cooling the suspended rotor, effectively preventing suspension failure caused by refrigerant overheating and vaporization, and ensuring high-speed, stable operation of the compressor rotor. The refrigerant, having completed heat exchange, flows out from the bottom of compressor 100 and re-enters the liquid supply device, forming a dedicated closed-loop cooling cycle independent of the main refrigeration cycle. This not only avoids disturbance to the main cycle system and ensures the overall performance stability of the high-temperature heat pump, but also reduces refrigerant loss, making the system operation more economical and reliable.

[0031] This entire cycle enables continuous and efficient cooling of the liquid refrigerant used for compressor bearing suspension, ultimately improving the operational reliability and service life of the air-suspended high-temperature heat pump.

[0032] In some feasible embodiments of the present invention, a second heat exchanger 2 is also included. The main inlet of the second heat exchanger 2 is connected to the outlet of the air suspension bearing, and the main outlet of the second heat exchanger 2 is connected to the inlet of the liquid supply device. By adding the above-mentioned post-heat exchange structure to the cooling circuit, a double protection for the circulating refrigerant is formed. After the liquid refrigerant enters the bearing and is suspended by the rotor, it flows out from the bottom of the compressor 100, passes through the second heat exchanger 2 again, and is cooled by the cold source water temperature of the second heat exchanger 2 before entering the liquid supply device. This further cools the liquid refrigerant, relieves the heat load absorbed by the refrigerant from the bearing, and reduces the temperature of the refrigerant returning to the liquid supply device. This not only protects the liquid supply device from continuous thermal shock from the high-temperature refrigerant and prevents pump cavitation and other failures that may be caused by local overheating, ensuring the stable operation of the liquid supply device, but also ensures that the temperature of the refrigerant entering the first heat exchanger is lower, creating more favorable initial conditions for the next round of deep cooling.

[0033] The first heat exchanger 1 and the second heat exchanger 2 can be plate heat exchangers, finned tube heat exchangers, shell-and-tube heat exchangers, or shell-and-tube heat exchangers. No specific restrictions are imposed here, as long as heat exchange can be achieved.

[0034] In some feasible embodiments of the present invention, the liquid supply device includes a storage tank 3 and a supply tank 5. The storage tank 3 has an outlet for supplying liquid refrigerant. By setting a two-stage tank structure that separates the storage tank 3 and the supply tank 5, a buffer and stabilization system can be formed, that is, the large amount of stored refrigerant is separated from the refrigerant directly supplied to the first heat exchanger 1, thus avoiding the direct impact of liquid level fluctuations in the storage tank 3 on the stability of liquid supply to downstream equipment.

[0035] Downstream of the liquid outlet is a gear pump 4; using the gear pump 4 as a power source to draw refrigerant from the liquid storage tank 3 can achieve precise and stable flow delivery, because as a positive displacement pump, the output flow rate of the gear pump is proportional to the rotation speed and is not easily affected by fluctuations in outlet pressure.

[0036] As an alternative embodiment, gear pump 4 can also be replaced with other types of pump bodies.

[0037] The liquid supply tank 5 is connected downstream of the liquid outlet and is also connected to the main inlet of the first heat exchanger 1. The storage tank 3 stores liquid refrigerant. The liquid level in the supply tank 5 is maintained by a gear pump 4 drawing liquid from the storage tank 3, employing an active level maintenance method. By controlling the start / stop or speed of the gear pump 4, the liquid level in the supply tank 5 can be precisely controlled within a preset small range in real time. It should be noted that a level gauge is also installed in the supply tank 5 to detect its liquid level.

[0038] In some feasible embodiments of the present invention, a motor cooling structure 6 is also included. The inlet of the motor cooling structure 6 is connected to the outlet of the gear pump 4, utilizing the pressure and flow generated by the gear pump 4 supplying liquid downstream, eliminating the need for an additional independent cooling pump for motor cooling. The outlet of the motor cooling structure 6 is connected to the main inlet of the second heat exchanger 2. Specifically, the outlet of the motor cooling structure 6 can merge with the outlet of the air suspension bearing before entering the storage tank 3, allowing the two cooled refrigerants to share a single return pipe. This reduces the number of pipes and connectors required to return to the storage tank 3, saving material and installation costs and reducing the overall footprint of the equipment. In other words, the liquid refrigerant in the storage tank 3, after passing through the gear pump 4, can be supplied to cool the motor. The cooled liquid refrigerant, along with the liquid refrigerant cooling the bearing, returns to the storage tank 3, thereby achieving motor cooling.

[0039] In some feasible embodiments of the present invention, a frequency converter cooling structure 7 is also included. The inlet of the frequency converter cooling structure 7 is connected to the outlet of the gear pump 4, and the outlet of the frequency converter cooling structure 7 is connected to the inlet of the liquid storage tank 3. The liquid refrigerant in the liquid storage tank 3, after passing through the gear pump 4, can be supplied to the frequency converter for cooling. The liquid refrigerant after the frequency converter is cooled returns to the liquid storage tank. In this way, the frequency converter can directly share the refrigerant and power source circulating in the air suspension bearing, without the need to add an additional circulation pump and piping system for frequency converter cooling.

[0040] In some feasible embodiments of the present invention, the inlet of the gear pump 4 is also connected to the condenser 200 and the evaporator 300 of the air-suspended high-temperature heat pump, respectively. A first valve 8 is provided between the inlet of the gear pump 4 and the condenser 200, and a second valve 9 is provided between the inlet of the gear pump 4 and the evaporator 300. In this embodiment, the gear pump 4 can also draw liquid from the condenser 200 and the evaporator 300. Usually, liquid is only drawn from the condenser 200 and the evaporator 300 at the beginning when the liquid level in the storage tank 3 is very low. After normal operation, the liquid level in the storage tank 3 is high enough that it is not necessary to draw liquid from both the condenser 200 and the evaporator 300. When liquid drawing is required, the first valve 8 and the second valve 9 are opened as needed; when liquid drawing is not needed, the first valve 8 and the second valve 9 are closed as needed.

[0041] In some feasible embodiments of the present invention, a first level gauge is installed inside the liquid storage tank 3, and a bypass valve 10 is also installed between the outlet of the gear pump 4 and the evaporator 300. In this embodiment, because the clearance of the static pressure air suspension bearing is small, the amount of gas leaking from the air suspension bearing to the compressor cavity is small, so the cooling system is relatively closed relative to the entire refrigerant circulation system. However, as long as there is a gap, gas leakage is inevitable. Therefore, as the compressor runs, the refrigerant level in the liquid storage tank 3 increases. When the detected level reaches a certain level, the bypass valve 10 of the liquid storage tank 3 is opened to pump the excess liquid refrigerant back to the evaporator 300 and re-enter the main refrigerant circulation system. This active drainage closed-loop control solves the problem of excessive refrigerant accumulation on the low-pressure side under specific operating conditions, ensuring the dynamic balance and stability of the refrigerant charge in the main circulation system.

[0042] In some feasible embodiments of the present invention, a pressure relief valve 11 is provided between the supply tank 5 and the storage tank 3 to provide a passive overpressure protection mechanism for the supply pipeline. When the pressure in the supply tank 5 rises abnormally due to fluctuations in the gear pump 4 or possible instantaneous blockage downstream, and exceeds the preset opening pressure of the pressure relief valve 11, the pressure relief valve 11 will automatically open, allowing some of the high-pressure liquid refrigerant to bypass and flow back to the low-pressure storage tank 3. In this embodiment, a pressure relief valve 11 is provided between the supply tank 5 and the storage tank 3 to prevent excessive pressure differential in the supply pressure to the air suspension bearing. As a high-precision component, the stable operation of the air suspension bearing is very sensitive to the supply pressure. Excessive pressure may disrupt its suspension stability or even damage its internal structure. Therefore, the pressure relief valve 11 ensures the safety and stability of the air suspension bearing under any operating conditions.

[0043] In some feasible embodiments of the present invention, a filter 12 is also provided between the liquid storage tank 3 and the gear pump 4. The filter 12 can filter the liquid refrigerant flowing out of the liquid storage tank 3, forming a protective barrier for the precision fluid components, especially directly protecting the gear pump 4. By outputting clean liquid refrigerant, the risk of impurities entering and circulating in the entire liquid circuit system is eliminated from the source, thereby ensuring the long-term stability and reliability of the entire system.

[0044] More specifically, the type of filter 12 is not limited; it can be a dryer filter, an intake filter, or a liquid line filter, as long as it can filter the liquid refrigerant.

[0045] In some feasible embodiments of the present invention, the cold source water for the first heat exchanger 1 and the second heat exchanger 2 includes tap water. By using tap water, the temperature of the liquid entering the air suspension bearing and the motor cooling can be controlled within a reasonable range. The liquid refrigerant partially vaporizes in the air suspension bearing throttling device, and its temperature decreases due to heat absorption during vaporization, while further cooling the bearing.

[0046] Therefore, the cooling system for air-suspended high-temperature heat pumps provided by this invention not only solves the problem of cooling the bearings and motors of high-temperature heat pumps and is easy to implement, but also solves the problem of easy failure of lubricating oil in high-temperature heat pumps by combining the characteristics of hydrostatic suspension without the need for lubricating oil. At the same time, it also solves the cooling problem of liquid-cooled frequency converters, and the system is relatively stable and unaffected by changes in operating conditions.

[0047] A second aspect of the present invention provides a heat pump unit, including a cooling system for an air-suspended high-temperature heat pump as described in any of the preceding claims.

[0048] The heat pump unit provided in this embodiment has the various advantages described above because it includes the cooling system for air-suspended high-temperature heat pumps as described above, which will not be repeated here.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cooling system for an air-suspended high-temperature heat pump, characterized in that, The air-suspended high-temperature heat pump includes a compressor, the compressor having an air-suspended bearing installed inside, and the cooling system includes: Liquid supply device, used to provide liquid refrigerant; The first heat exchanger has a cold source water flowing through its auxiliary side. The main inlet of the first heat exchanger is connected to the outlet of the liquid supply device, and the main outlet of the first heat exchanger is connected to the inlet of the air suspension bearing. The outlet of the air suspension bearing is also connected to the inlet of the liquid supply device.

2. The cooling system for an air-suspended high-temperature heat pump according to claim 1, characterized in that, Also includes: The second heat exchanger has its main inlet connected to the outlet of the air suspension bearing, and its main outlet connected to the inlet of the liquid supply device.

3. The cooling system for an air-suspended high-temperature heat pump according to claim 2, characterized in that, The liquid supply device includes: A liquid storage tank has an outlet for supplying liquid refrigerant, and a gear pump is connected downstream of the outlet. A liquid supply tank is connected downstream of the liquid outlet, and the liquid supply tank is connected to the main inlet of the first heat exchanger.

4. The cooling system for an air-suspended high-temperature heat pump according to claim 3, characterized in that, Also includes: The motor cooling structure has an inlet connected to the outlet of the gear pump and an outlet connected to the main inlet of the second heat exchanger.

5. The cooling system for an air-suspended high-temperature heat pump according to claim 3, characterized in that, Also includes: The inverter cooling structure has its inlet connected to the outlet of the gear pump and its outlet connected to the inlet of the liquid storage tank.

6. The cooling system for an air-suspended high-temperature heat pump according to claim 4 or 5, characterized in that, The inlet of the gear pump is also connected to the condenser and evaporator of the air-suspended high-temperature heat pump, and a first valve is provided between the inlet of the gear pump and the condenser, and a second valve is provided between the inlet of the gear pump and the evaporator.

7. The cooling system for an air-suspended high-temperature heat pump according to claim 6, characterized in that, The storage tank is equipped with a first level gauge, and a bypass valve is also provided between the outlet of the gear pump and the evaporator.

8. The cooling system for an air-suspended high-temperature heat pump according to claim 3, characterized in that, A pressure relief valve is provided between the supply tank and the storage tank.

9. The cooling system for an air-suspended high-temperature heat pump according to claim 3, characterized in that, A filter is also provided between the liquid storage tank and the gear pump.

10. A heat pump unit, characterized in that, Includes the cooling system for air-suspended high-temperature heat pumps as described in any one of claims 1-9.

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