A centrifuge heat pump system for producing high-temperature steam using negative pressure steam.

Abstract

The application relates to the technical field of industrial waste heat recovery, in particular to a centrifuge heat pump system for preparing high-temperature steam by using negative pressure steam, which comprises a flash tank and a heat pump unit. Specifically, the heat pump unit comprises a compressor for increasing the pressure of refrigerant, a condenser for making the pressurized refrigerant release heat and condense, a throttling device for reducing the pressure of the condensed refrigerant, and an evaporator for making the reduced-pressure refrigerant absorb heat and evaporate; the compressor, the condenser, the throttling device and the evaporator are connected through pipelines to form a refrigerant circulation system; a low-temperature heat source input port of the evaporator is connected with an external negative pressure steam source, and the evaporator is also used for condensing steam into liquid and outputting the liquid into the flash tank at least; a high-temperature heat source input port of the condenser is connected with a saturated liquid outlet of the flash tank, and a high-temperature heat source output port of the condenser is connected with a feeding port of the flash tank. The application has the effects of reducing energy waste and realizing efficient utilization of negative pressure steam.

Description

Technical Field

[0001] This application relates to the field of industrial waste heat recovery technology, and in particular to a centrifuge heat pump system that uses negative pressure steam to produce high-temperature steam. Background Technology

[0002] In industrial production sectors such as chemical, pharmaceutical, food processing, and textile printing and dyeing, numerous processes, including evaporation, concentration, distillation, and drying, commonly generate and release steam at lower temperatures and pressures than atmospheric pressure—i.e., negative pressure steam. This type of steam typically carries the latent heat input during production, but due to its low pressure and poor quality, it is difficult to directly reuse it in process equipment requiring medium- to high-temperature heat sources. Most factories condense this negative pressure steam directly into liquid water using condensation towers or cooling systems. However, this method not only wastes energy but also runs counter to the current trends of energy conservation, emission reduction, and the development of a circular economy.

[0003] Meanwhile, on the same factory's production line, many core processes, such as high-temperature reactions, sterilization, and steam-powered processes, continuously require a stable supply of high-pressure, high-temperature steam. To meet this demand, factories typically rely on purchasing high-pressure steam externally or configuring dedicated coal-fired, gas-fired boilers or electric heating devices to produce it fresh. This operating model, which "wastes low-temperature heat energy on the one hand and consumes additional primary energy to generate high-temperature steam on the other," leads to a significant increase in enterprise operating costs and persistently high carbon emissions.

[0004] Therefore, there is an urgent need for an innovative technology and system that can efficiently and economically convert negative pressure steam, which is commonly emitted by factories and is difficult to use directly, into high-pressure, high-temperature steam that can be directly used in core production processes. Summary of the Invention

[0005] In order to reduce energy waste and achieve efficient utilization of negative pressure steam, this application provides a centrifuge heat pump system for producing high-temperature steam using negative pressure steam.

[0006] The centrifuge heat pump system for producing high-temperature steam using negative pressure steam provided in this application adopts the following technical solution:

[0007] A centrifuge heat pump system for producing high-temperature steam using negative pressure steam includes:

[0008] Flash evaporator;

[0009] The heat pump unit includes a compressor for increasing refrigerant pressure, a condenser for releasing heat and condensing the pressurized refrigerant, a throttling device for reducing the pressure of the condensed refrigerant, and an evaporator for absorbing heat and evaporating the depressurized refrigerant. The compressor, condenser, throttling device, and evaporator are connected by pipelines to form a refrigerant circulation system. The low-temperature heat source inlet of the evaporator is connected to an external negative pressure vapor source. The evaporator is also used to condense vapor into liquid and output it at least into the flash tank. The high-temperature heat source inlet of the condenser is connected to the saturated liquid outlet of the flash tank, and the high-temperature heat source outlet of the condenser is connected to the feed inlet of the flash tank.

[0010] By adopting the above technical solution, this system solves the technical bottleneck in existing technologies where negative pressure steam cannot directly enter the heat pump unit to exchange heat with the refrigerant through the coupled design of the flash tank and the heat pump unit. Specifically, firstly, by using negative pressure steam as the "low-temperature heat source" of the heat pump unit's evaporator, the negative pressure steam can directly enter the evaporator to exchange heat with the refrigerant, avoiding the energy gradient waste of conventional systems that require steam to be condensed into water before evaporator heat exchange. This also recovers the huge latent heat contained in the negative pressure steam, achieving efficient extraction of low-grade waste heat. Secondly, this system innovatively uses the condensate formed after the evaporator condenses the negative pressure steam as the consumable liquid of the flash tank, and uses the high-temperature heat released by the condenser to heat this liquid, producing the high-temperature steam required for production without the need for an external water source.

[0011] Optionally, a water replenishment and adjustment unit is also included, which includes a storage tank, a first delivery pump, a first liquid level sensor, and a first controller; the low-temperature heat source output port of the evaporator is connected to the input port of the storage tank; the input end of the first delivery pump is connected to the output port of the storage tank, and the output end of the first delivery pump is connected to the inner cavity of the flash tank; the first liquid level sensor is disposed inside the flash tank and is used to collect first liquid level information in the flash tank; the first controller is electrically connected to the first liquid level sensor and is used to control the output flow rate of the first delivery pump according to the first liquid level information.

[0012] By adopting the above technical solution and setting up a water replenishment and regulation unit including a storage tank, a level sensor, and a first delivery pump, the flow rate decoupling and buffer regulation between condensate production and high-temperature steam generation are achieved. Specifically, due to the fluctuation of negative pressure steam in industrial production and the discontinuity of downstream high-temperature steam consumption, the amount of condensate produced by the evaporator often does not perfectly match the demand of the flash tank. By setting up a storage tank, excess condensate produced by the evaporator can be temporarily stored; when the flash tank level is insufficient or during peak steam consumption periods, the first controller controls the first delivery pump to increase the flow rate to replenish the condensate based on feedback from the first level sensor. This design reduces the possibility of system downtime caused by fluctuations in the raw material supply to the flash tank, playing a "peak shaving and valley filling" role, and improving the system's operational stability and adaptability to different operating conditions.

[0013] Optionally, it also includes a vacuum unit. The evaporator includes a refrigerant cylinder and a heat exchanger. The refrigerant cylinder contains refrigerant for flow heat exchange. The heat exchanger is used to exchange heat and cool the refrigerant in the refrigerant cylinder with the negative pressure steam output from the negative pressure steam source. The heat exchanger includes multiple heat exchange tubes and a mixing tank. The multiple heat exchange tubes all pass through the refrigerant cylinder. The input end of the heat exchange tube is connected to an external negative pressure steam source, and the output end of the heat exchange tube is connected to the inner cavity of the mixing tank. The mixing tank has a first non-condensable gas outlet. The vacuum unit is used to extract non-condensable gas from the mixing tank through the first non-condensable gas outlet.

[0014] By adopting the above technical solution, a mixing tank and an extraction unit are installed at the end of the evaporator's heat exchanger, effectively solving the problem of reduced heat exchange efficiency caused by non-condensable gases mixed in negative pressure steam. Specifically, during the condensation process of negative pressure steam, non-condensable gases tend to accumulate at the end or locally of the heat exchange tubes, forming a gas film that hinders heat transfer. The mixing tank utilizes gravity to separate the liquid from the steam condensate at the heat exchange tubes, and then extracts the gas through the first non-condensable gas outlet in conjunction with the extraction unit. This effectively reduces the formation of a gas film, thereby improving the heat transfer coefficient of the evaporator and the overall energy efficiency ratio of the heat pump unit.

[0015] Optionally, the pumping unit includes an ejector and a first gas-liquid separator; the main fluid inlet of the ejector is connected to the output end of the first delivery pump, and the ejector fluid inlet of the ejector is connected to the first non-condensable gas outlet; the inlet of the first gas-liquid separator is connected to the mixed fluid outlet of the ejector, and the liquid phase outlet of the first gas-liquid separator is connected to the inner cavity of the storage tank.

[0016] By adopting the above technical solution and through the coordinated design of the ejector and the first gas-liquid separator, the dual effects of optimized pumping power and reduced working fluid loss are achieved. Specifically, firstly, the liquid flow output from the first delivery pump is reused as the main fluid of the ejector, and the design utilizes the negative pressure generated by the high-speed fluid jet to draw non-condensable gases from the mixing tank. Simultaneously, considering that during the extraction of non-condensable gases, the high-speed airflow easily carries away some condensate droplets or uncondensed vapor, which would result in wasted working fluid if not treated, the first gas-liquid separator effectively separates the gas-liquid mixture discharged from the ejector. On the one hand, it discharges the non-condensable gases; on the other hand, it intercepts the working fluid used for ejection and the portion of condensate carried away by the gas, returning it to the storage tank via the liquid phase outlet. This ensures the continuous operation of the ejection cycle, reduces waste caused by condensate discharge with non-condensable gases, and further improves the system's water resource utilization rate and operational economy.

[0017] Optionally, the extraction unit further includes a first control valve, a first temperature sensor, a first pressure sensor, and a second controller; the first control valve is located between the first non-condensable gas outlet and the ejector fluid inlet of the ejector, and is used to control the on / off state of non-condensable gas entering the ejector fluid inlet; the first temperature sensor is used to collect the first temperature information of the condensate output from the low-temperature heat source outlet of the evaporator; the first pressure sensor is used to collect the first pressure information of the refrigerant in the refrigerant cylinder; the second controller is electrically connected to the first control valve, the first temperature sensor, and the first pressure sensor, and is used to calculate the first quantity information of non-condensable gas in the mixing tank based on the first temperature information and the first pressure information, and control the opening and closing of the first control valve based on the first quantity information.

[0018] By adopting the above technical solution, the second controller can calculate the deviation between the theoretical saturation state of the refrigerant side pressure and the condensate side temperature using the first temperature information collected by the first temperature sensor and the first pressure information collected by the first pressure sensor. This allows for accurate determination of whether non-condensable gases sufficient to affect heat exchange have accumulated in the mixing tank. The first control valve is opened when non-condensable gases are detected in the mixing tank, and closed when no non-condensable gases are detected. This ensures that the first control valve is only opened to extract gas when non-condensable gases are detected in the mixing tank. This avoids resource losses caused by the vapor condensate being extracted along with the non-condensable gases due to the first control valve being constantly open, and also avoids the unnecessary consumption of ejector fluid energy due to blind extraction, achieving intelligent control of the system's non-condensable gas discharge process.

[0019] Optionally, the evaporator further includes a steam distribution cylinder, the inlet of which is used to connect to an external negative pressure steam source; multiple heat exchangers are provided, and multiple heat exchange tubes of the multiple heat exchangers correspond one-to-one with multiple branch outlets of the steam distribution cylinder, and the inlet of the heat exchange tube is connected to the branch outlet of the steam distribution cylinder.

[0020] By adopting the above technical solution, the steam distribution cylinder can evenly distribute the input negative pressure steam to multiple heat exchange tubes of each heat exchanger, avoiding the phenomenon of "dry burning" of some heat exchanger tubes or excessive load on some heat exchanger tubes due to uneven flow distribution, thereby improving the overall heat exchange efficiency and operational reliability of the evaporator.

[0021] Optionally, the extraction unit further includes a second control valve and a second pressure sensor electrically connected to the second controller; a second non-condensable gas outlet is provided on the steam distribution cylinder, and the ejector fluid inlet of the ejector is connected to the second non-condensable gas outlet; the second control valve is located between the second non-condensable gas outlet and the ejector fluid inlet, and is used to control the on / off state of non-condensable gas input into the ejector fluid inlet; the second pressure sensor is used to collect second pressure information of the negative pressure steam in the steam distribution cylinder; the second controller can obtain third temperature information of the negative pressure steam output from the external negative pressure steam source, and the second controller is also used to calculate second inventory information of non-condensable gas in the steam distribution cylinder based on the third temperature information and the second pressure information, and control the opening and closing of the second control valve based on the second inventory information.

[0022] By adopting the above technical solution, a second non-condensable gas outlet and a corresponding second control valve are added at the steam distribution cylinder, achieving dual degassing of the "inlet end" and "outlet end" of the evaporator cooling source. Specifically, considering that this system operates under negative pressure for a long time, when the system is shut down, outside air easily penetrates and accumulates in the lower-pressure steam distribution cylinder. If not dealt with in time, this accumulated non-condensable gas will immediately enter the heat exchange tubes upon restarting, forming a gas lock and blocking steam flow. Therefore, the above design allows for bidirectional suction of non-condensable gas in both the steam distribution cylinder (inlet) and the mixing tank (outlet) using the extraction unit before or at the initial stage of system startup. On the one hand, it can quickly eliminate the gas accumulated during shutdown before system startup, establishing a good vacuum environment; on the other hand, it can ensure that the non-condensable gas inside the evaporator from the steam distribution end to the condensation end is completely purged, preventing gas lock, thereby ensuring that the system can be put into operation in a highly efficient heat exchange state immediately upon startup.

[0023] Optionally, the water replenishment adjustment unit further includes a second liquid level sensor and a drain valve electrically connected to the first controller; the second liquid level sensor is located inside the storage tank and is used to collect information on the second liquid level in the storage tank; the input end of the drain valve is connected to the output port of the storage tank, and the output end of the drain valve is connected to the atmosphere; the first controller is also used to control the opening and closing of the drain valve according to the second liquid level information.

[0024] By adopting the above technical solution, the cooperation between the second liquid level sensor and the drain valve realizes an automatic anti-overflow protection mechanism for the storage tank. Specifically, when the upstream negative pressure steam volume is too large, causing the condensate generation rate to far exceed the consumption rate of the flash evaporator, and the liquid level in the storage tank reaches the warning line, the system automatically opens the drain valve to discharge the excess condensate. This effectively prevents liquid from overflowing the storage tank and flowing back into the evaporator or causing abnormal increases in system pressure, thus improving the stability and safety of system operation.

[0025] Optionally, the water replenishment adjustment unit further includes a second temperature sensor and a heater electrically connected to the first controller; the second temperature sensor is used to detect the second temperature information of the saturated liquid in the flash tank, and the heater is used to heat the saturated liquid in the flash tank; the first controller is also used to control the heating power of the heater according to the second temperature information.

[0026] By adopting the above technical solution, precise auxiliary heating and constant temperature control of the liquid in the flash tank can be achieved, ensuring that the saturated liquid in the flash tank is always maintained within a suitable flash temperature range. This allows for precise control of the enthalpy of the makeup water, preventing excessively cold liquid from directly entering the flash tank and causing a sharp drop in flash efficiency or disrupting the thermal balance within the flash tank. Especially during winter startup or low-load operation of the unit, this design can significantly shorten the preheating time for the system to reach rated steam production, ensuring the stability of the quality of the high-temperature steam output.

[0027] Optionally, a gas-liquid separation unit is also included, comprising a second gas-liquid separation tank, a third liquid level sensor, a second delivery pump, and a third controller; the inlet of the second gas-liquid separation tank is connected to the steam outlet of the flash tank; the third liquid level sensor is used to collect third liquid level information in the second gas-liquid separation tank; the inlet of the second delivery pump is connected to the liquid phase outlet of the second gas-liquid separation tank; the outlet of the second delivery pump is connected to the high-temperature heat source inlet of the condenser; the third controller is electrically connected to the second delivery pump and is used to control the output flow rate of the second delivery pump according to the third liquid level information.

[0028] By adopting the above technical solution, secondary purification of the high-temperature steam produced by the flash tank is achieved. Specifically, the steam produced during flash evaporation often carries some liquid droplets. By adding a gas-liquid separation unit, not only can the liquid droplets in the steam be effectively removed, improving the steam dryness, but the separated high-temperature saturated liquid can also be returned to the high-temperature heat source inlet of the condenser to participate in the cycle heating and flash evaporation again. This reduces the waste of high-grade hot water and improves the system's economy and overall thermal efficiency.

[0029] In summary, this application includes the following beneficial technical effects:

[0030] 1. This system, through the coupled design of the flash tank and heat pump unit, solves the technical bottleneck in existing technologies where negative pressure steam cannot directly enter the heat pump unit for heat exchange with the refrigerant. Specifically, firstly, by utilizing negative pressure steam as a "low-temperature heat source" for the evaporator of the heat pump unit, the negative pressure steam can directly enter the evaporator for heat exchange with the refrigerant, avoiding the energy waste of the conventional system that requires steam to be condensed into water before evaporator heat exchange. This also recovers the huge latent heat contained in the negative pressure steam, achieving efficient extraction of low-grade waste heat. Secondly, this system innovatively uses the condensate formed after the evaporator condenses the negative pressure steam as the consumable liquid of the flash tank, and uses the high-temperature heat released by the condenser to heat this liquid, producing the high-temperature steam required for production without the need for an external water source.

[0031] 2. The coordinated design of the ejector and the first gas-liquid separator achieves the dual benefits of optimized pumping power and reduced working fluid loss. Specifically, firstly, the liquid flow output from the first delivery pump is reused as the main fluid for the ejector, and the negative pressure generated by the high-speed fluid jet is used to draw non-condensable gases from the mixing tank. Simultaneously, considering that during the extraction of non-condensable gases, the high-speed airflow easily carries away some condensate droplets or uncondensed vapor, which would result in wasted working fluid if not treated, the first gas-liquid separator effectively separates the gas-liquid mixture discharged from the ejector. On the one hand, it discharges the non-condensable gases; on the other hand, it intercepts the working fluid used for ejection and the portion of condensate carried away by the gas, returning it to the storage tank via the liquid phase outlet. This ensures the continuous operation of the ejector cycle, reduces waste caused by condensate discharge with non-condensable gases, and further improves the system's water resource utilization and operational economy.

[0032] 3. The second controller can calculate the deviation between the theoretical saturation state of the refrigerant side pressure and the condensate side temperature using the first temperature information collected by the first temperature sensor and the first pressure information collected by the first pressure sensor. This allows for accurate determination of whether non-condensable gases sufficient to affect heat exchange have accumulated in the mixing tank. The first control valve is opened when non-condensable gases are detected in the mixing tank, and closed when no non-condensable gases are detected. This ensures that the first control valve is only opened to evacuate gas when non-condensable gases are detected in the mixing tank. This avoids resource loss caused by the vapor condensate being extracted along with the non-condensable gases due to the first control valve being constantly open, and also avoids the unnecessary consumption of ejector fluid energy due to blind evacuation, achieving intelligent control of the system's non-condensable gas discharge process. Attached Figure Description

[0033] Figure 1 This is a system diagram of an embodiment of this application.

[0034] Figure 2 yes Figure 1 A magnified view of part A in the middle.

[0035] Explanation of reference numerals in the attached diagram: 1. Flash tank; 11. Saturated liquid outlet; 12. Feed inlet; 13. Steam outlet; 2. Heat pump unit; 21. Compressor; 22. Condenser; 221. High-temperature heat source inlet; 222. High-temperature heat source outlet; 23. Throttling device; 24. Evaporator; 2401. Low-temperature heat source inlet; 2402. Low-temperature heat source outlet; 241. Refrigerant cylinder; 242. Heat exchanger; 2421. Heat exchange tube; 2422. Mixing tank; 24221. First non-condensable gas outlet; 243. Steam separator; 2431. Second non-condensable gas outlet; 3. Vacuum extraction unit; 31. Ejector; 311. Main fluid inlet; 312. Ejector fluid inlet; 313. Mixed fluid outlet 32. First gas-liquid separator; 33. First control valve; 34. First temperature sensor; 35. First pressure sensor; 36. Second control valve; 37. Second pressure sensor; 38. Air pump; 4. Water replenishment adjustment unit; 41. Storage tank; 42. First transfer pump; 43. First liquid level sensor; 44. Second liquid level sensor; 45. Drain valve; 46. Second temperature sensor; 47. Heater; 5. Gas-liquid separation unit; 51. Second gas-liquid separator; 52. Third liquid level sensor; 53. Second transfer pump; 6. Third transfer pump; 10. First pipeline; 20. Second pipeline; 30. Third pipeline; 40. Fourth pipeline; 50. Fifth pipeline; 60. Sixth pipeline; 70. Seventh pipeline. Detailed Implementation

[0036] The following combination Figures 1-2 This application will be described in further detail.

[0037] This application discloses a centrifuge heat pump system for producing high-temperature steam using negative pressure steam.

[0038] In this embodiment, the centrifuge heat pump system includes a flash tank 1, a heat pump unit 2, an air extraction unit 3, a water replenishment and adjustment unit 4, and a gas-liquid separation unit 5.

[0039] The heat pump unit 2 includes a compressor 21 for increasing the refrigerant pressure, a condenser 22 for releasing heat and condensing the pressurized refrigerant, a throttling device 23 for reducing the pressure of the condensed refrigerant, and an evaporator 24 for absorbing heat and evaporating the depressurized refrigerant. The compressor 21, condenser 22, throttling device 23, and evaporator 24 are connected by pipelines to form a refrigerant circulation system. The low-temperature heat source inlet 2401 of the evaporator 24 is connected to an external negative pressure vapor source. The evaporator 24 is also used to condense vapor into liquid and output it to at least the flash tank 1. The high-temperature heat source inlet 221 of the condenser 22 is connected to the saturated liquid outlet 11 of the flash tank 1, and the high-temperature heat source outlet 222 of the condenser 22 is connected to the feed inlet 12 of the flash tank 1.

[0040] Specifically, compressor 21 can be a centrifugal compressor, which has advantages such as high efficiency and large flow rate. Compressor 21 is generally driven by an electric motor, and the power and speed of the motor are matched according to the system requirements. Condenser 22 can be a shell-and-tube condenser, which features compact structure and high heat transfer efficiency. Condenser 22 is usually composed of a shell, heat exchange device, etc., and the refrigerant flows in the heat exchange device, exchanging heat with the fluid outside the tubes. Throttling device 23 can be an expansion valve or orifice plate, etc.

[0041] The output port of compressor 21 is connected to the refrigerant inlet of condenser 22 via a pipe. The refrigerant output port of condenser 22 is connected to the input end of throttling device 23 via a pipe. The output end of throttling device 23 is connected to the refrigerant inlet of evaporator 24. The refrigerant output port of evaporator 24 is connected to the input port of compressor 21 via a pipe. The high-temperature heat source inlet 221 of condenser 22 is connected to the saturated liquid outlet 11 of flash tank 1 via first pipe 10. The high-temperature heat source outlet 222 of condenser 22 is connected to the feed inlet 12 of flash tank 1 via second pipe 20. A third delivery pump 6 is installed on the second pipe 20 to increase the flow rate and pressure of the saturated liquid output from the high-temperature heat source outlet 222 of condenser 22. In other embodiments, compressor 21 may also be a screw compressor; condenser 22 may also be a plate condenser.

[0042] In this way, the system solves the technical bottleneck in existing technologies where negative pressure steam cannot directly enter the heat pump unit to exchange heat with the refrigerant through the coupled design of the flash tank and the heat pump unit. Specifically, firstly, by using negative pressure steam as the "low-temperature heat source" of the evaporator 24 of the heat pump unit, the negative pressure steam can directly enter the evaporator 24 to exchange heat with the refrigerant, avoiding the energy waste of the conventional system that requires steam to be condensed into water before heat exchange in the evaporator 24, and recovering the huge latent heat contained in the negative pressure steam, thus achieving efficient extraction of low-grade waste heat. Secondly, the system innovatively uses the condensate formed after the negative pressure steam is condensed in the evaporator 24 as the consumable liquid of the flash tank 1, and uses the high-temperature heat released by the condenser 22 to heat this liquid, producing the high-temperature steam required for production without the need for an external water source.

[0043] In this embodiment, the evaporator 24 includes a refrigerant cylinder 241, multiple heat exchangers 242, and a steam distribution cylinder 243. The refrigerant cylinder 241 provides a space for the refrigerant, and the heat exchangers 242 are used to exchange heat with the refrigerant in the refrigerant cylinder 241 after the negative pressure steam output from the external negative pressure steam source is cooled down and condensed to form condensate.

[0044] The heat exchanger 242 includes multiple heat exchange tubes 2421 and a mixing tank 2422. The heat exchange tubes 2421 can be made of copper or stainless steel, depending on the requirements. Copper tubes have good thermal conductivity, while stainless steel tubes have good corrosion resistance. The multiple heat exchange tubes 2421 are arranged in a side-by-side array and all penetrate the refrigerant cylinder 241. The mixing tank 2422 is used to collect the condensate formed after the negative pressure vapor has undergone heat exchange and condensation, as well as non-condensable gases. The low-temperature heat source outlet 2402 of the evaporator 24 is located at the bottom of the mixing tank 2422.

[0045] The inlet of the steam distributor 243 is used to connect to an external negative pressure steam source, and the inlet of the steam distributor 243 is the low-temperature heat source inlet 2401 of the evaporator 24. The function of the steam distributor 243 is to evenly distribute the input negative pressure steam to the multiple heat exchange tubes 2421 of each heat exchanger 242. The steam distributor 243 is also a cylindrical tank with baffles and diversion holes inside to ensure that the steam can flow evenly to each heat exchange tube 2421. The multiple heat exchange tubes 2421 of the multiple heat exchangers 242 correspond one-to-one with the multiple diversion outlets of the steam distributor 243. The inlet of the heat exchange tube 2421 is connected to the external negative pressure steam source through the diversion outlet of the steam distributor 243; the outlet of the heat exchange tube 2421 is connected to the inner cavity of the mixing tank 2422.

[0046] The water replenishment and adjustment unit 4 includes a storage tank 41, a first delivery pump 42, a first liquid level sensor 43, and a first controller (not shown in the attached drawings). The storage tank 41 is a sealed tank used to store the condensate produced by the evaporator 24. The storage tank 41 is generally located below the evaporator 24, and the condensate can flow into the storage tank 41 by gravity. The low-temperature heat source output port 2402 of the evaporator 24 is connected to the input port of the storage tank 41 through a third pipe 30, and the output port of the storage tank 41 is connected to the inner cavity of the flash tank 1 through a fourth pipe 40.

[0047] The first transfer pump 42 is used to transfer the liquid in the storage tank 41 to the flash tank 1. The first transfer pump 42 can be a centrifugal pump with characteristics such as large flow rate and moderate head. The first transfer pump 42 is installed on the fourth pipe 40. The input end of the first transfer pump 42 is connected to the output port of the storage tank 41 through the fourth pipe 40, and the output end of the first transfer pump 42 is connected to the inner cavity of the flash tank 1 through the fourth pipe 40.

[0048] The first liquid level sensor 43 is installed inside the flash tank 1 and is used to collect information on the first liquid level inside the flash tank 1. The first liquid level sensor 43 can be a float-type liquid level sensor, an ultrasonic liquid level sensor, etc. The float-type liquid level sensor detects the liquid level by the up and down movement of a float, while the ultrasonic liquid level sensor measures the liquid level by emitting and receiving ultrasonic waves.

[0049] The first controller can be an electronic device with data processing and signal control capabilities, such as a programmable logic controller, a microcontroller, an industrial control computer, or a general-purpose central processing unit. The first controller is electrically connected to the first liquid level sensor 43 and is used to control the output flow rate of the first transfer pump 42 based on the first liquid level information. When the liquid level in the flash tank 1 is low, the first controller controls the first transfer pump 42 to increase its flow rate to replenish the flash tank 1; when the liquid level is high, it controls the first transfer pump 42 to decrease its flow rate or stop operating.

[0050] In this way, the design of multiple heat exchangers 242 enables sufficient and uniform heat exchange between the negative pressure steam and the refrigerant in the refrigerant cylinder 241; the steam distribution cylinder 243 can evenly distribute the input negative pressure steam to the multiple heat exchange tubes 2421 of each heat exchanger 242, avoiding the phenomenon of some heat exchanger tubes 2421 "dry burning" or excessive load on some heat exchanger tubes 2421 due to uneven flow distribution. The two work together to improve the overall heat exchange efficiency and operational reliability of the evaporator 24.

[0051] The water replenishment and regulation unit 4 achieves flow decoupling and buffer regulation between condensate production and high-temperature steam generation. Specifically, due to the fluctuation of negative pressure steam in industrial production and the discontinuity of high-temperature steam consumption at the downstream end, the amount of condensate produced by the evaporator 24 often does not perfectly match the demand of the flash tank 1. By setting up a storage tank 41, excess condensate produced by the evaporator 24 can be temporarily stored; when the liquid level in the flash tank 1 is insufficient or during peak steam consumption periods, the first controller controls the first delivery pump 42 to increase the flow rate for replenishment based on feedback from the first liquid level sensor 43. This design reduces the possibility of system downtime caused by fluctuations in the raw material supply to the flash tank 1, plays a role in "peak shaving and valley filling," and improves the system's operational stability and adaptability to operating conditions.

[0052] In this embodiment, the top of the mixing tank 2422 is also provided with a first non-condensable gas outlet 24221. The pumping unit 3 is used to extract non-condensable gas in the mixing tank 2422 through the first non-condensable gas outlet 24221. The pumping unit 3 includes an ejector 31 and a first gas-liquid separator 32.

[0053] The main fluid inlet 311 of the ejector 31 is connected to the output end of the first delivery pump 42 via the fourth pipe 40; the ejector fluid inlet 312 of the ejector 31 is connected to the first non-condensable gas outlet 24221 via the fifth pipe 50. The first gas-liquid separator 32 can be a gravity-type gas-liquid separator, which separates gas and liquid by utilizing the difference in gas and liquid density; the first gas-liquid separator 32 can also be a cyclone-type gas-liquid separator, which separates gas and liquid by centrifugal force. The inlet of the first gas-liquid separator 32 is connected to the mixed fluid outlet 313 of the ejector 31, the liquid phase outlet of the first gas-liquid separator 32 is connected to the inner cavity of the storage tank 41, and the gas phase outlet of the first gas-liquid separator 32 is connected to the atmosphere.

[0054] In this way, during the negative pressure steam condensation process, non-condensable gases tend to accumulate at the end or locally of the heat exchange tube 2421, forming a gas film that hinders heat transfer. However, by installing a mixing tank 2422, gravity is used to separate the fluid output from the heat exchange tube 2421, which consists of the steam condensate and the non-condensable gases, and the mixture is extracted through the first non-condensable gas outlet 24221 in conjunction with the extraction unit 3. This effectively reduces the formation of a gas film, thereby improving the heat transfer coefficient of the evaporator 24 and the overall energy efficiency ratio of the heat pump unit.

[0055] Furthermore, the extraction unit 3 adopts a design that combines the ejector 31 with the first gas-liquid separator 32, and reuses the liquid flow output by the first delivery pump 42 as the main fluid of the ejector 31 to extract the non-condensable gas in the mixing tank 2422.

[0056] Furthermore, considering that during the extraction of non-condensable gases, the high-speed airflow is prone to entraining some condensate droplets or uncondensed vapors during discharge, the first gas-liquid separator 32 effectively separates the gas-liquid mixture discharged from the ejector 31. This allows the working fluid used for ejection, along with some condensate entrained by the gas, to be intercepted and returned to the storage tank 41 via the liquid phase outlet while the non-condensable gases are being discharged. This ensures the continuous operation of the ejection cycle, reduces waste caused by condensate discharge with non-condensable gases, and further improves the system's water resource utilization and operational economy.

[0057] Preferably, the gas phase outlet of the first gas-liquid separator 32 is further provided with a vacuum pump 38 for extracting gas from the first gas-liquid separator 32. This reduces the back pressure of the ejector 31 and increases the internal expansion ratio of the ejector 31. This allows the ejector 31 to achieve a larger ejection coefficient under the same main fluid pressure. Furthermore, it enables the formation of a negative pressure within the first gas-liquid separator 32, facilitating the stable discharge of the gas phase.

[0058] In this embodiment, the extraction unit 3 further includes a first control valve 33, a first temperature sensor 34, a first pressure sensor 35, a second controller (not shown in the accompanying drawings), a second control valve 36, and a second pressure sensor 37. The first control valve 33 is disposed on the fifth pipe 50 and is located between the first non-condensable gas outlet 24221 and the ejector fluid inlet 312 of the ejector 31, and is used to control the on / off state of the non-condensable gas in the mixing tank 2422 entering the ejector fluid inlet 312 of the ejector 31.

[0059] The first temperature sensor 34 can be a thermocouple temperature sensor or a thermistor temperature sensor. It is located on the third pipe 30 and is used to collect the first temperature information of the condensate output from the low-temperature heat source outlet 2402 of the evaporator 24. The first pressure sensor 35 is a pressure transmitter, located on the refrigerant cylinder 241, and is used to collect the first pressure information of the refrigerant within the refrigerant cylinder 241.

[0060] The second controller can also be an electronic device with data processing and signal control capabilities, such as a programmable logic controller, a microcontroller, an industrial control computer, or a general-purpose central processing unit. The second controller is electrically connected to the first control valve 33, the first temperature sensor 34, and the first pressure sensor 35. It is used to calculate the first quantity of non-condensable gas in the mixing tank 2422 based on the first temperature and first pressure information, and to control the opening and closing of the first control valve 33 based on the first quantity information. When the calculation indicates the presence of non-condensable gas, the first control valve 33 is opened to evacuate the gas; when the calculation indicates the absence of non-condensable gas, the first control valve 33 is closed.

[0061] In this way, the second controller can calculate the deviation between the theoretical saturation state of the refrigerant side pressure and the condensate side temperature using the first temperature information collected by the first temperature sensor 34 and the first pressure information collected by the first pressure sensor 35, and accurately determine whether non-condensable gases sufficient to affect heat exchange have accumulated in the mixing tank 2422. When it is determined that non-condensable gases are present in the mixing tank 2422, the first control valve 33 is opened; when it is determined that no non-condensable gases are present in the mixing tank 2422, the first control valve 33 is closed. This achieves the goal of only opening the first control valve 33 to extract gas when non-condensable gases are detected in the mixing tank 2422. This avoids resource loss caused by the vapor condensate being extracted along with the non-condensable gases due to the first control valve 33 being constantly open, and also avoids the unnecessary consumption of ejector fluid energy due to blind extraction, thus achieving intelligent control of the system's non-condensable gas discharge process.

[0062] In this embodiment, the second controller is also electrically connected to the second control valve 36 and the second pressure sensor 37. A second non-condensable gas outlet 2431 is provided on the steam distribution cylinder 243. The ejector fluid inlet 312 of the ejector 31 is connected to the second non-condensable gas outlet 2431 through the sixth pipe 60. The second control valve 36 is located on the sixth pipe 60, between the second non-condensable gas outlet 2431 and the ejector fluid inlet 312 of the ejector 31, and is used to control the on / off state of non-condensable gas input into the ejector fluid inlet 312 of the ejector 31.

[0063] The second pressure sensor 37 is also a pressure transmitter. It is mounted on the steam separator 243 and is used to collect the second pressure information of the negative pressure steam within the steam separator 243. The second controller can also acquire the third temperature information of the negative pressure steam output from the external negative pressure steam source in real time. The second controller is also used to calculate the second quantity information of non-condensable gases in the steam separator 243 based on the third temperature information and the second pressure information, and to control the opening and closing of the second control valve 36 based on this second quantity information. When it is calculated that there are non-condensable gases, the second control valve 36 is opened to evacuate gas; when it is calculated that there are no non-condensable gases, the second control valve 36 is closed.

[0064] Because the system operates under negative pressure for extended periods, outside air can easily penetrate and accumulate in the lower-pressure steam separator 243 after the system shuts down. If not addressed promptly, this accumulated non-condensable gas will enter the heat exchange tube 2421 and form a gas lock when the system restarts, blocking steam flow.

[0065] The above design allows for bidirectional suction of non-condensable gases in both the steam distribution cylinder 243 and the mixing tank 2422 using the suction unit 3 before or during system startup. This not only quickly eliminates gases accumulated during shutdown and establishes a good vacuum environment before system startup, but also ensures that non-condensable gases from the steam distribution end to the condensation end inside the evaporator 24 are completely purged, preventing gas lock and thus ensuring that the system can operate in a highly efficient heat exchange state immediately upon startup.

[0066] In this embodiment, the water replenishment and adjustment unit 4 further includes a second liquid level sensor 44, a drain valve 45, a second temperature sensor 46, and a heater 47, all electrically connected to the first controller. The second liquid level sensor 44 is located inside the storage tank 41 and is used to collect information on the second liquid level within the storage tank 41. The second liquid level sensor 44 can also be a float-type liquid level sensor, an ultrasonic liquid level sensor, or the like.

[0067] The vent valve 45 can be a solenoid valve or the like. The input end of the vent valve 45 is connected to the output port of the liquid storage tank 41 through the fourth pipe 40, and the output end of the vent valve 45 is connected to the atmosphere. The second temperature sensor 46 can also be a thermocouple temperature sensor or a thermistor temperature sensor. The second temperature sensor 46 is installed on the first pipe 10 and is used to detect the second temperature information of the saturated liquid in the flash tank 1.

[0068] The heater 47 can be a coil-type electric heater or other heat source. The heater 47 is installed inside the flash tank 1 and is used to heat the saturated liquid inside the flash tank 1. The first controller is also used to control the opening and closing of the drain valve 45 according to the second liquid level information, and to control the start and stop of the heater 47 and the heating power according to the second temperature information.

[0069] In this way, when the upstream negative pressure steam volume is too large, causing the condensate generation rate to far exceed the consumption rate of flash tank 1, and the liquid level in storage tank 41 reaches the warning line, the first controller can open the drain valve 45 to discharge the excess condensate. This prevents liquid from overflowing storage tank 41 and flowing back into evaporator 24 or causing abnormal pressure rise in the system, thus improving the stability and safety of system operation. At the same time, the first controller can control the heating power of heater 47 to ensure that the saturated liquid in flash tank 1 is always maintained within a suitable flash temperature range. This allows for precise control of the enthalpy of makeup water, preventing overcooled liquid from directly entering flash tank 1, which could cause a sudden drop in flash efficiency or disrupt the thermal balance within flash tank 1.

[0070] In this embodiment, the gas-liquid separation unit 5 includes a second gas-liquid separation tank 51, a third liquid level sensor 52, a second delivery pump 53, and a third controller (not shown in the accompanying drawings). The inlet of the second gas-liquid separation tank 51 is connected to the steam outlet 13 of the flash tank 1 via a pipe, and the liquid phase outlet of the second gas-liquid separation tank 51 is connected to the first pipe 10 via a seventh pipe 70, thereby connecting to the high-temperature heat source inlet 221 of the condenser 22.

[0071] The third liquid level sensor 52 is installed inside the second gas-liquid separator 51 and is used to collect the third liquid level information inside the second gas-liquid separator 51. The third liquid level sensor 52 can also be a float-type liquid level sensor, an ultrasonic liquid level sensor, etc.

[0072] The second transfer pump 53 is used to transfer the liquid in the second gas-liquid separator 51 to the high-temperature heat source inlet 221 of the condenser 22. The second transfer pump 53 can be a centrifugal pump with characteristics such as large flow rate and moderate head. The second transfer pump 53 is installed on the seventh pipe 70. The input end of the second transfer pump 53 is connected to the liquid phase outlet of the second gas-liquid separator 51 through the seventh pipe 70, and the output end of the second transfer pump 53 is connected to the high-temperature heat source inlet 221 of the condenser 22 through the seventh pipe 70.

[0073] The third controller can also be an electronic device with data processing and signal control capabilities, such as a programmable logic controller, a microcontroller, an industrial control computer, or a general-purpose central processing unit. The third controller is electrically connected to the second transfer pump 53 and is used to control the output flow rate of the second transfer pump 53 based on the third liquid level information.

[0074] Since the steam produced during flash evaporation often carries some liquid droplets, adding a gas-liquid separation unit 5 can not only effectively remove the droplets from the steam and improve its dryness, but also return the separated high-temperature saturated liquid to the high-temperature heat source inlet 221 of the condenser 22 for re-entry into the cycle heating and flash evaporation process. This reduces the waste of high-grade hot water and improves the system's economy and overall thermal efficiency.

[0075] The implementation principle of this application embodiment is as follows: This system solves the dual technical problems of the prior art—that negative pressure steam cannot be directly utilized and that factories need to consume additional primary energy to obtain high-temperature steam—through the coupled design of the flash tank 1 and the heat pump unit 2. Specifically, firstly, negative pressure steam is used as a "low-temperature heat source" for the evaporator 24 of the heat pump unit. Waste negative pressure steam from external industrial production is introduced into the specially structured evaporator 24 for heat exchange, recovering the huge latent heat contained in the negative pressure steam and achieving efficient extraction of low-grade waste heat. Secondly, this system creatively uses the condensate formed after the evaporator 24 condenses the negative pressure steam directly as the consumable liquid of the flash tank 1, and uses the high-temperature heat released by the condenser 22 to heat this liquid, causing it to flash-evaporate in the flash tank 1 to generate high-pressure, high-temperature steam. This system achieves cascaded energy utilization (upgrading low-grade thermal energy to high-grade thermal energy), reducing the company's operating costs and carbon emissions. It also enables the recycling of water resources, allowing the production of high-temperature steam without the need for an external water source. Furthermore, to maintain the negative pressure of this system, an additional extraction system and related start-up and operation control systems are added to ensure stable system operation. The system's flow rate and liquid level balance are also rationally designed and controlled, which to some extent solves a series of heat exchange and operational problems related to directly introducing negative pressure steam into the unit.

[0076] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A centrifuge heat pump system for producing high-temperature steam using negative pressure steam, characterized in that, include: Flash evaporator (1); The heat pump unit (2) includes a compressor (21) for increasing the refrigerant pressure, a condenser (22) for releasing heat and condensing the pressurized refrigerant, a throttling device (23) for reducing the pressure of the condensed refrigerant, and an evaporator (24) for absorbing heat and evaporating the depressurized refrigerant. The compressor (21), the condenser (22), the throttling device (23), and the evaporator (24) are connected by pipelines to form a refrigerant circulation system. The low-temperature heat source inlet (2401) of the evaporator (24) is connected to an external negative pressure vapor source. The evaporator (24) is also used to condense the vapor into liquid and output it to at least the flash tank (1). The high-temperature heat source inlet (221) of the condenser (22) is connected to the saturated liquid outlet (11) of the flash tank (1), and the high-temperature heat source outlet (222) of the condenser (22) is connected to the feed inlet (12) of the flash tank (1). It also includes a water replenishment adjustment unit (4), which includes a storage tank (41), a first delivery pump (42), a first liquid level sensor (43), and a first controller; the low-temperature heat source output port (2402) of the evaporator (24) is connected to the input port of the storage tank (41); the input end of the first delivery pump (42) is connected to the output port of the storage tank (41), and the output end of the first delivery pump (42) is connected to the inner cavity of the flash tank (1); the first liquid level sensor (43) is located inside the flash tank (1) and is used to collect the first liquid level information inside the flash tank (1); the first controller is electrically connected to the first liquid level sensor (43) and is used to control the output flow rate of the first delivery pump (42) according to the first liquid level information; It also includes an extraction unit (3), and the evaporator (24) includes a refrigerant cylinder (241) and a heat exchanger (242); the refrigerant cylinder (241) contains refrigerant for flow heat exchange, and the heat exchanger (242) is used to exchange heat and cool down the refrigerant in the refrigerant cylinder (241) with the negative pressure steam output from the negative pressure steam source; the heat exchanger (242) includes multiple heat exchange tubes (2421) and a mixing tank (2422), and the multiple heat exchange tubes (2421) All of them pass through the refrigerant cylinder (241). The input end of the heat exchange tube (2421) is connected to an external negative pressure steam source, and the output end of the heat exchange tube (2421) is connected to the inner cavity of the mixing tank (2422). The mixing tank (2422) is provided with a first non-condensable gas outlet (24221). The pumping unit (3) is used to extract the non-condensable gas in the mixing tank (2422) through the first non-condensable gas outlet (24221).

2. A centrifuge heat pump system for producing high-temperature steam using negative pressure steam according to claim 1, characterized in that: The extraction unit (3) includes an ejector (31) and a first gas-liquid separator (32); the main fluid inlet (311) of the ejector (31) is connected to the output end of the first delivery pump (42), and the ejector fluid inlet (312) of the ejector (31) is connected to the first non-condensable gas outlet (24221); the inlet of the first gas-liquid separator (32) is connected to the mixed fluid outlet (313) of the ejector (31), and the liquid phase outlet of the first gas-liquid separator (32) is connected to the inner cavity of the storage tank (41).

3. A centrifuge heat pump system for producing high-temperature steam using negative pressure steam according to claim 2, characterized in that: The extraction unit (3) further includes a first control valve (33), a first temperature sensor (34), a first pressure sensor (35), and a second controller. The first control valve (33) is located between the first non-condensable gas outlet (24221) and the ejector fluid inlet (312) of the ejector (31), and is used to control the on / off state of non-condensable gas input into the ejector fluid inlet (312) of the ejector (31). The first temperature sensor (34) is used to collect the first temperature information of the condensate output from the low-temperature heat source outlet (2402) of the evaporator (24). The first pressure sensor (35) is used to collect the first pressure information of the refrigerant in the refrigerant cylinder (241). The second controller is electrically connected to the first control valve (33), the first temperature sensor (34), and the first pressure sensor (35). The second controller is used to calculate the first quantity information of non-condensable gas in the mixing tank (2422) based on the first temperature information and the first pressure information, and control the opening and closing of the first control valve (33) based on the first quantity information.

4. A centrifuge heat pump system for producing high-temperature steam using negative pressure steam according to claim 3, characterized in that: The evaporator (24) also includes a steam distribution cylinder (243), the inlet of which is used to connect to an external negative pressure steam source; there are multiple heat exchangers (242), and the multiple heat exchange tubes (2421) of the multiple heat exchangers (242) correspond one-to-one with the multiple diversion outlets of the steam distribution cylinder (243), and the inlet of the heat exchange tube (2421) is connected to the diversion outlet of the steam distribution cylinder (243).

5. A centrifuge heat pump system for producing high-temperature steam using negative pressure steam according to claim 4, characterized in that: The extraction unit (3) further includes a second control valve (36) and a second pressure sensor (37) electrically connected to the second controller; a second non-condensable gas outlet (2431) is provided on the steam distribution cylinder (243), and the ejector fluid inlet (312) of the ejector (31) is connected to the second non-condensable gas outlet (2431); the second control valve (36) is located between the second non-condensable gas outlet (2431) and the ejector fluid inlet (312) of the ejector (31) for controlling the non-condensable gas. The input is the on / off state of the ejector fluid inlet (312) of the ejector (31); the second pressure sensor (37) is used to collect the second pressure information of the negative pressure steam in the steam distribution cylinder (243); the second controller can obtain the third temperature information of the negative pressure steam output by the external negative pressure steam source, and the second controller is also used to calculate the second quantity information of non-condensable gas in the steam distribution cylinder (243) according to the third temperature information and the second pressure information, and control the opening and closing of the second control valve (36) according to the second quantity information.

6. A centrifuge heat pump system for producing high-temperature steam using negative pressure steam according to claim 1, characterized in that: The water replenishment adjustment unit (4) further includes a second liquid level sensor (44) and a drain valve (45) electrically connected to the first controller; the second liquid level sensor (44) is located inside the storage tank (41) and is used to collect the second liquid level information inside the storage tank (41); the input end of the drain valve (45) is connected to the output port of the storage tank (41), and the output end of the drain valve (45) is connected to the atmosphere; the first controller is also used to control the opening and closing of the drain valve (45) according to the second liquid level information.

7. A centrifuge heat pump system for producing high-temperature steam using negative pressure steam according to claim 1, characterized in that: The water replenishment adjustment unit (4) further includes a second temperature sensor (46) and a heater (47) electrically connected to the first controller; the second temperature sensor (46) is used to detect the second temperature information of the saturated liquid in the flash tank (1), and the heater (47) is used to heat the saturated liquid in the flash tank (1); the first controller is also used to control the heating power of the heater (47) according to the second temperature information.

8. A centrifuge heat pump system for producing high-temperature steam using negative pressure steam according to claim 1, characterized in that: It also includes a gas-liquid separation unit (5), which includes a second gas-liquid separation tank (51), a third liquid level sensor (52), a second delivery pump (53), and a third controller; the inlet of the second gas-liquid separation tank (51) is connected to the steam outlet (13) of the flash tank (1); the third liquid level sensor (52) is used to collect the third liquid level information in the second gas-liquid separation tank (51); the inlet of the second delivery pump (53) is connected to the liquid phase outlet of the second gas-liquid separation tank (51); and the outlet of the second delivery pump (53) is connected to the high temperature heat source inlet (221) of the condenser (22); the third controller is electrically connected to the second delivery pump (53) and is used to control the output flow rate of the second delivery pump (53) according to the third liquid level information.

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