Air suspension heat pump double-effect evaporation device

Abstract

The utility model provides a kind of gas suspension heat pump double-effect evaporation device, can solve the problem of not high energy utilization rate in existing low-temperature evaporation technology, can improve the stability of system operation, wherein one effect evaporation unit includes one effect separator and the coil heat exchanger being set in one effect separator;Two-effect evaporation unit includes two-effect separator and two-effect forced circulation heat exchanger;Gas suspension heat pump unit output end and the inlet end of coil heat exchanger are communicated, for compressed high-temperature refrigerant gas is delivered to coil heat exchanger;One effect separator and two-effect separator are connected into raw liquid system respectively, one effect steam outlet of one effect separator and the heat source inlet of two-effect forced circulation heat exchanger are communicated, for heating to be evaporated material liquid in two-effect forced circulation heat exchanger, two-effect steam outlet of two-effect separator and the input end of gas suspension heat pump unit are communicated, for recycling the waste heat of two-effect steam generated by two-effect separator.

Description

Technical Field

[0001] This utility model relates to the field of evaporation equipment technology, and in particular to a dual-effect evaporation device for air suspension heat pump. Background Technology

[0002] Evaporators are key units for liquid concentration or recovery in many fields such as chemical industry, food and pharmaceutical industry, and environmental protection.

[0003] Traditional single-effect evaporation has low thermal efficiency and huge energy consumption. To reduce energy consumption, multi-effect evaporation and MVR have been developed. The former has achieved energy-saving breakthroughs through "steam cascade utilization", but it still has limitations: it requires multiple devices in series, has a large footprint and high investment, and the more effects there are, the higher the system resistance and scaling risk. The latter achieves energy internal circulation through "mechanical compression of secondary steam", but in practical applications, when treating complex industrial wastewater, MVR has the problem of scaling on the heat exchanger surface, which leads to an increase in the boiling point of the evaporated liquid. This results in an increase in the temperature difference required by the compressor, a sharp increase in power consumption, a decrease in evaporation capacity, and even the need for shutdown and cleaning, resulting in low system stability.

[0004] To address scaling issues and protect heat-sensitive materials, a low-temperature vacuum evaporator was developed. However, existing low-temperature evaporators also have shortcomings: low heat utilization rate, failure to utilize latent heat of vaporization in stages, resulting in waste heat; and heat pump systems often use conventional oil-lubricated compressors, which are prone to lubrication oil return difficulties under negative pressure conditions, potentially leading to compressor wear or even damage, affecting the long-term stable operation of the system. Utility Model Content

[0005] To address the aforementioned issues, this invention provides a dual-effect evaporation device for air-suspension heat pumps, which can solve the problem of low energy utilization in existing low-temperature evaporation technologies and improve the stability of system operation.

[0006] The technical solution is as follows: a dual-effect evaporation device for air-suspension heat pumps, characterized in that it includes: A single-effect evaporation unit, comprising a single-effect separator and a coil heat exchanger disposed within the single-effect separator; The double-effect evaporation unit includes a double-effect separator and a double-effect forced circulation heat exchanger. An air-suspension heat pump unit, wherein the output end of the air-suspension heat pump unit is connected to the inlet end of the coil heat exchanger, and is used to deliver the compressed high-temperature refrigerant gas to the coil heat exchanger. The first-effect separator and the second-effect separator are respectively connected to the raw liquid system. The first-effect steam outlet of the first-effect separator is connected to the heat source inlet of the second-effect forced circulation heat exchanger to heat the liquid to be evaporated in the second-effect forced circulation heat exchanger. The second-effect steam outlet of the second-effect separator is connected to the input end of the air suspension heat pump unit to recover the waste heat of the second-effect steam generated by the second-effect separator.

[0007] Furthermore, the first-effect evaporation unit also includes a first-effect circulation pump, and the outlet of the first-effect separator is connected to the circulation inlet of the first-effect separator through the first-effect circulation pump for circulating the liquid in the first-effect separator.

[0008] Furthermore, the double-effect evaporation unit also includes a double-effect circulation pump, and the outlet of the double-effect separator is connected to the feed inlet of the double-effect forced circulation heat exchanger through the double-effect circulation pump; the feed outlet of the double-effect forced circulation heat exchanger is connected to the circulation inlet of the double-effect separator.

[0009] Furthermore, it also includes a transfer pump, which connects the first-effect separator and the second-effect separator, and is used to transport the concentrated liquid in the first-effect separator to the second-effect separator.

[0010] Furthermore, it also includes a vacuum pumping unit, which is connected to the air suspension heat pump unit and is used to maintain the vacuum level in the first-effect evaporation unit and the second-effect evaporation unit.

[0011] Furthermore, it also includes a distillation water discharge unit, which is connected to the condensate outlet of the air suspension heat pump unit and is used to collect the condensate after the second-effect steam is condensed; the distillation water discharge unit is connected to the condensate outlet of the second-effect forced circulation heat exchanger and is used to collect the condensate after the first-effect steam is condensed.

[0012] Furthermore, the double-effect separator is also connected to a discharge pump for discharging the concentrated liquid in the double-effect separator.

[0013] Furthermore, the air-suspension heat pump unit employs an air-suspension compressor.

[0014] Compared with the prior art, the present invention has the following advantages: This utility model of a dual-effect evaporator using an air-suspension heat pump combines dual-effect evaporation with heat pump technology. The heat energy generated by the air-suspension heat pump unit drives the evaporation of the first-effect separator, and the first-effect steam generated by the first-effect separator serves as a heat source to drive the evaporation of the second-effect separator, thus realizing the cascade utilization of energy. At the same time, the secondary steam generated by the second-effect separator is recovered by the heat pump unit, resulting in extremely high heat utilization of the entire system. It does not require external steam or cooling water, which can significantly reduce operating energy consumption. The air-suspension heat pump dual-effect evaporation device of this utility model operates under negative pressure conditions through a vacuum unit, which reduces scaling of the liquid and corrosion of the equipment. In addition, both the first and second effect evaporation units are equipped with circulation pumps to force the liquid to circulate, enhance heat transfer, and effectively flush the heat exchange surface, further inhibiting scaling and ensuring that the equipment can operate stably for a long time. The heat pump unit of this utility model adopts an air-suspension compressor. The air-suspension compressor utilizes gas dynamic pressure bearing technology, so the rotor does not contact the bearing during operation and no lubricating oil is required. This solves the problem of difficult oil return in traditional compressors in vacuum evaporation applications, avoids lubricating oil contamination of the system and compressor damage, and improves the reliability and service life of the device. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a dual-effect evaporation device for an air-suspension heat pump in one of the embodiments. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0017] See Figure 1 The present invention provides a dual-effect evaporation device for an air-suspension heat pump, comprising: A single-effect evaporation unit 100 includes a single-effect separator 101 and a coil heat exchanger 102 disposed within the single-effect separator 101. The coil heat exchanger 102 is installed in the liquid phase region of the single-effect separator 101. The outside of the coil is the raw liquid to be heated, and the inside of the coil is high-temperature and high-pressure refrigerant gas from the air suspension heat pump unit 300. The coil heat exchanger 102 is built into the single-effect separator 101, with a large heating area and high heat exchange efficiency. The double-effect evaporation unit 200 includes a double-effect separator 201 and a double-effect forced circulation heat exchanger 202. The air-suspension heat pump unit 300 has its output end connected to the inlet end of the coil heat exchanger 102. It is used to deliver compressed high-temperature refrigerant gas to the coil heat exchanger 102. In this embodiment, the air-suspension heat pump unit 300 employs an air-suspension compressor. The air-suspension compressor utilizes gas dynamic bearing technology, where the rotor is supported and suspended by a gas film during high-speed rotation, without any mechanical contact or lubrication. This solves the problem of oil return under vacuum conditions and avoids the risk of compressor damage due to poor lubrication. Furthermore, since the refrigerant circulation loop is completely oil-free, it avoids the problems of lubricating oil contaminating the refrigerant, reducing heat exchange efficiency, and contaminating condensate, thus improving the long-term operational stability of the entire device and enhancing the quality of the produced water. In this embodiment, the air-suspension heat pump unit 300 typically also includes a throttling valve and an evaporator. The coil heat exchanger can serve as the condenser of the air-suspension heat pump unit 300.

[0018] The first-effect separator 101 and the second-effect separator 201 are respectively connected to the raw liquid system 1. The first-effect steam outlet 101C of the first-effect separator 101 is connected to the heat source inlet 202A of the second-effect forced circulation heat exchanger 202 to heat the liquid to be evaporated in the second-effect forced circulation heat exchanger 202. The second-effect steam outlet 201A of the second-effect separator 201 is connected to the input end of the air suspension heat pump unit 300 to recover the waste heat of the second-effect steam generated by the second-effect separator 201, which can be used to condense the second-effect steam.

[0019] In this embodiment, the total heat exchange area is increased by designing a first-effect separator 101 and a second-effect separator 201 in series, thereby increasing the processing capacity compared to a single-effect system. The air-suspension heat pump unit 300 absorbs heat from the condensation process of the secondary steam in the second-effect evaporator. Combined with the work done by the air-suspension compressor, the refrigerant enters the first-effect evaporator at a higher temperature. At the same time, the first-effect steam generated by the first-effect separator drives the second-effect evaporator. Compared with traditional low-temperature evaporators where the heat pump only drives single-effect evaporation, this invention enables the electrical energy input from the compressor to leverage more heat in the system to participate in the evaporation process, thereby significantly improving energy utilization efficiency and reducing system energy consumption.

[0020] In this embodiment, the first-effect evaporation unit further includes a first-effect circulation pump 103. The outlet 101A of the first-effect separator 101 is connected to the circulation inlet 101B of the first-effect separator 101 through the first-effect circulation pump 103, for circulating the liquid in the first-effect separator 101. In this embodiment, the second-effect evaporation unit further includes a second-effect circulation pump 203. The outlet 201B of the second-effect separator is connected to the liquid inlet 202B of the second-effect forced circulation heat exchanger through the second-effect circulation pump 203. The liquid outlet 202C of the second-effect forced circulation heat exchanger is connected to the circulation inlet 201C of the second-effect separator. The first-effect circulation pump and the second-effect circulation pump drive the liquid in the first-effect separator and the second-effect separator to circulate in a forced manner, which improves heat transfer and forms a continuous scouring effect on the heat exchange surface, further reducing the deposition of scale on the heat exchange surface and extending the continuous operation time of the equipment.

[0021] In one embodiment, a transfer pump 400 is also included, connected to the first-effect separator 101 and the second-effect separator 201. The transfer pump 400 is used to transport the concentrated liquid in the first-effect separator 101 to the second-effect separator 201. The transfer pump 400 enables the device to achieve deep concentration of materials. The concentrated liquid from the first-effect separator enters the second-effect separator, where the pressure and temperature are lower, for further evaporation. For certain materials, this process can be used to achieve crystallization under low-temperature conditions, thus broadening the application range of the device. For example, when treating saline wastewater, the first-effect separator concentrates the wastewater to near saturation. After being transferred to the second-effect separator, it reaches a supersaturated state at a lower temperature, precipitating salt crystals, thus achieving solid-liquid separation and resource utilization.

[0022] In one embodiment, a vacuum unit 700 is also included. The vacuum unit 700 is connected to the air suspension heat pump unit 300 and is used to maintain the vacuum level in the first-effect evaporation unit and the second-effect evaporation unit. The vacuum system maintains the system under vacuum negative pressure conditions, and the boiling point of the raw liquid is reduced to a low temperature range, which inhibits scaling and corrosion that are prone to occur at high temperatures.

[0023] In one embodiment, a distillation water discharge unit 500 is also included. The distillation water discharge unit 500 is connected to the condensate outlet 300A of the air suspension heat pump unit and is used to collect the condensate after the second-effect steam is condensed. The distillation water discharge unit 500 is connected to the condensate outlet 202D of the second-effect forced circulation heat exchanger and is used to collect the condensate after the first-effect steam is condensed. The two streams of condensate are collected in the collection tank of the distillation water discharge unit 500. Since the entire evaporation process is carried out under vacuum and low temperature conditions and the refrigerant circulation loop is oil-free, the produced distilled water has high purity.

[0024] In one embodiment, the double-effect separator 201 is also connected to a discharge pump 204 for discharging the concentrate in the double-effect separator 201.

[0025] The air-suspension heat pump dual-effect evaporator in the embodiment operates as follows: At startup, the vacuum unit is activated first to draw the pressure in the first-effect separator and the second-effect separator to the set vacuum level, which is used to lower the boiling point of the liquid. Then, the liquid to be treated is injected into the first-effect separator and the second-effect separator to the working level through the raw liquid inlet system. During the evaporation process, the air suspension heat pump unit is started, the air suspension compressor starts working, and the first-effect circulation pump and the second-effect circulation pump are started. The air-suspension compressor compresses the refrigerant into a high-temperature, high-pressure gas, which is then transported to the coil-type heat exchanger inside the first-effect separator. Inside the coil-type heat exchanger, the high-temperature, high-pressure gas releases its latent heat of condensation, heating the liquid circulating outside the tubes, driven by the first-effect circulation pump, to boiling point and generating first-effect steam. The first-effect steam generated by the first-effect separator is discharged from the first-effect steam outlet and enters the second-effect forced circulation heat exchanger. The liquid inside the second-effect separator is pumped by the second-effect circulation pump, flows through the second-effect forced circulation heat exchanger, and is heated by the first-effect steam. The heated liquid evaporates in the second-effect separator, generating second-effect steam. The steam from the first effect is condensed into distilled water in the second effect forced circulation heat exchanger and discharged from the condensate outlet to be collected by the distilled water discharge unit; the steam from the second effect is drawn out from the second effect steam outlet and enters the air suspension heat pump unit for condensation, and the condensate is discharged through the distilled water discharge system to be collected by the distilled water discharge unit. As evaporation proceeds, the concentration of the liquid in the first-effect separator gradually increases. When the preset value is reached, the transfer pump connecting the first-effect separator and the second-effect separator is started to transport the concentrated liquid from the first effect to the second-effect separator for further evaporation and crystallization. Finally, the concentrated liquid containing crystals in the second-effect separator is discharged through the discharge pump at the bottom of the second-effect separator.

[0026] In this embodiment, the liquid in the first-effect separator is forcibly circulated by a first-effect circulating pump, so that the liquid flows through the outer surface of the coil heat exchanger, which enhances the heat transfer effect and has a scouring effect on the heat exchange surface, thereby inhibiting scaling.

[0027] In this embodiment, the liquid in the double-effect separator is pumped into the double-effect forced circulation heat exchanger for heating by a double-effect circulating pump. The heated liquid is then returned to the double-effect separator for evaporation, thus separating the heating process from the boiling process to avoid boiling and scaling on the double-effect forced circulation heat exchanger.

[0028] In this embodiment, the concentrated liquid after evaporation in the first-effect separator is transported to the second-effect separator by a transfer pump for further concentration or crystallization. After the concentrated liquid enters the second-effect separator, the solubility decreases further due to the lower temperature, making it easier to reach a supersaturated state. Crystals can precipitate under low-temperature conditions. The transfer pump is used to transport the concentrated liquid to the second-effect separator, so that the entire device can efficiently process the raw liquid and stably process high-concentration concentrated liquids or even concentrated liquids containing crystals, making it widely applicable.

[0029] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

[0030] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A dual-effect evaporation device for air-suspension heat pumps, characterized in that, include: A single-effect evaporation unit, comprising a single-effect separator and a coil heat exchanger disposed within the single-effect separator; The double-effect evaporation unit includes a double-effect separator and a double-effect forced circulation heat exchanger. An air-suspension heat pump unit, the output end of which is connected to the inlet end of the coil heat exchanger, is used to transport the compressed high-temperature and high-pressure refrigerant gas to the coil heat exchanger. The first-effect separator and the second-effect separator are respectively connected to the raw liquid system. The first-effect steam outlet of the first-effect separator is connected to the heat source inlet of the second-effect forced circulation heat exchanger to heat the liquid to be evaporated in the second-effect forced circulation heat exchanger. The second-effect steam outlet of the second-effect separator is connected to the input end of the air suspension heat pump unit to recover the waste heat of the second-effect steam generated by the second-effect separator.

2. The air-suspension heat pump dual-effect evaporation device according to claim 1, characterized in that: The single-effect evaporation unit also includes a single-effect circulation pump. The outlet of the single-effect separator is connected to the circulation inlet of the single-effect separator through the single-effect circulation pump, which is used to circulate the liquid in the single-effect separator.

3. The air-suspension heat pump dual-effect evaporation device according to claim 1, characterized in that: The double-effect evaporation unit also includes a double-effect circulation pump. The outlet of the double-effect separator is connected to the feed inlet of the double-effect forced circulation heat exchanger through the double-effect circulation pump. The feed outlet of the double-effect forced circulation heat exchanger is connected to the circulation inlet of the double-effect separator.

4. The air-suspension heat pump dual-effect evaporation device according to claim 1, characterized in that: It also includes a transfer pump, which connects the first-effect separator and the second-effect separator, and is used to transport the concentrated liquid in the first-effect separator to the second-effect separator.

5. The air-suspension heat pump dual-effect evaporation device according to claim 1, characterized in that: It also includes a vacuum pumping unit, which is connected to the air suspension heat pump unit and is used to maintain the vacuum level in the first-effect evaporation unit and the second-effect evaporation unit.

6. The air-suspension heat pump dual-effect evaporation device according to claim 1, characterized in that: It also includes a distillation water discharge unit, which is connected to the condensate outlet of the air suspension heat pump unit and is used to collect the condensate after the second-effect steam is condensed; the distillation water discharge unit is connected to the condensate outlet of the second-effect forced circulation heat exchanger and is used to collect the condensate after the first-effect steam is condensed.

7. The air-suspension heat pump dual-effect evaporation device according to claim 1, characterized in that: The double-effect separator is also connected to a discharge pump for discharging the concentrated liquid from the double-effect separator.

8. The air-suspension heat pump dual-effect evaporation device according to claim 1, characterized in that: The air-suspension heat pump unit includes an air-suspension compressor.

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