An energy recovery system

Abstract

The utility model relates to an energy recovery system, including evaporative chamber, heater, supercooler, condenser, compressor, cooler, condensate tank and vacuum pump, evaporative chamber communicates with heater, and heater communicates with condenser through supercooler, and condenser communicates with heater through compressor, and condenser communicates with evaporative chamber, and condenser communicates with condensate tank through cooler, and condensate tank communicates with vacuum pump, the refrigerant of condenser is arranged in shell -side, and the secondary steam generated by evaporative chamber enters the tube -side of condenser, the utility model discloses secondary steam into the tube -side of condenser, not easy to adhere to the inner surface of heat exchange pipe, and easy to clean, and the refrigerant enters the shell -side of condenser from top to bottom, and after vaporization, flows out condenser again upwards, avoids the risk of entraining liquid refrigerant, and has better protection to compressor, and the refrigerant returns to condenser again after the action of supercooler, ensures that the refrigerant enters condenser after overall liquefaction, and greatly improves the heat absorption efficiency of refrigerant.

Description

Technical Field

[0001] This utility model relates to the field of chemical evaporation technology, specifically to an energy recovery system, and more particularly to an energy recovery system suitable for closed-loop concentration equipment. Background Technology

[0002] Current energy-saving evaporation and concentration equipment (heat pump technology) recovers and reuses the heat in the secondary steam generated by evaporation through an intermediate medium (refrigerant) to achieve energy saving. A shell-and-tube heat exchanger transfers the heat of the secondary steam to the refrigerant, which then processes and reuses the heat. In recovering and reusing the heat from the secondary steam, the secondary steam typically flows through the shell side while the refrigerant flows through the tube side. The disadvantages of this method are: because the secondary steam flows through the shell side, entrained materials in the steam easily adhere to the outer surface of the heat exchange tubes and cannot be cleaned; the high density of heat exchange tubes in the shell side leads to significant condensation and liquefaction of the steam, resulting in a large pressure difference between the inlet and outlet of the shell side due to the limited flow space and high resistance to condensate discharge, leading to poor temperature distribution and insufficient heat exchange; and the short and unobstructed tube side easily carries away partially vaporized liquid refrigerant, which flows into the compressor and impacts the compressor impeller.

[0003] In addition, if the refrigerant that has absorbed heat is reused, its gas-liquid mixture will often emulsify if it is not treated again, which is detrimental to the subsequent heat absorption process. Utility Model Content

[0004] The purpose of this invention is to provide an energy recovery system that addresses the problems inherent in the condenser, the core component for heat recovery, during the operation of the aforementioned evaporation and concentration equipment, as well as the low heat absorption efficiency of the refrigerant in an emulsified state.

[0005] To achieve the above objectives, this utility model provides an energy recovery system, including an evaporation chamber, a heater, a subcooler, a condenser, a compressor, a cooler, a condensate tank, and a vacuum pump;

[0006] The evaporation chamber is connected to the heater, the heater is connected to the condenser through the subcooler, the condenser is connected to the heater through the compressor, the condenser is connected to the evaporation chamber, the condenser is connected to the condensate tank through the cooler, and the condensate tank is connected to the vacuum pump.

[0007] The refrigerant in the condenser is located in the shell side, while the secondary vapor generated in the evaporator enters the tube side of the condenser.

[0008] Preferably, a feed valve is provided on the feed pipe of the evaporation chamber.

[0009] Preferably, the heater is provided with a refrigerant outlet pipe, and a safety valve is provided on the refrigerant outlet pipe.

[0010] Preferably, a first manual valve is provided on the pipeline connecting the subcooler and the heater, and a second manual valve and an electronic expansion valve are sequentially provided on the pipeline connecting the subcooler and the condenser.

[0011] Preferably, the end of the first manual valve away from the subcooler is connected to the end of the second manual valve away from the subcooler via a third manual valve.

[0012] Preferably, an oil separator is provided between the compressor and the heater.

[0013] Preferably, a vacuum valve is installed on the pipeline connecting the condensate tank and the vacuum pump.

[0014] Preferably, the condenser is a falling film condenser.

[0015] Preferably, the heat of the secondary steam generated in the evaporation chamber is greater than the heat absorbed by the refrigerant in the condenser.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The core component of the heat recovery in this utility model, the condenser, adopts a configuration where the refrigerant flows through the shell side and the secondary steam flows through the tube side. The refrigerant flows through the shell side, completing heat absorption and vaporization before flowing upwards out of the condenser, eliminating the risk of entrained liquid refrigerant and providing better protection for the compressor. The flow of gaseous refrigerant through the shell side is not affected by the small space within the shell side, resulting in high heat exchange efficiency. The secondary steam flows through the tube side, preventing entrained materials from adhering to the outer surface of the heat exchange tubes and making them difficult to clean. Even if they adhere to the inner surface of the heat exchange tubes, they are very easy to clean.

[0018] 2. In this invention, after the refrigerant flows out of the heater, it passes through the subcooler and then returns to the condenser, ensuring that the refrigerant is fully liquefied before entering the condenser, thus greatly improving the heat absorption efficiency of the refrigerant. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] In the picture:

[0021] 1-Feed valve; 2-Evaporation chamber; 3-Heater; 4-Safety valve; 5-First manual valve; 6-Second manual valve; 7-Third manual valve; 8-Subcooler; 9-Electronic expansion valve; 10-Condenser; 11-Compressor; 12-Oil separator; 13-Cooler; 14-Condensate tank; 15-Vacuum valve; 16-Vacuum pump. Detailed Implementation

[0022] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0023] Example 1:

[0024] An energy recovery system, such as Figure 1 As shown, the system includes an evaporation chamber 2, a heater 3, a subcooler 8, a condenser 10, a compressor 11, a cooler 13, a condensate tank 14, and a vacuum pump 16. The evaporation chamber 2 is connected to the heater 3, the heater 3 is connected to the condenser 10 via the subcooler 8, the condenser 10 is connected to the heater 3 via the compressor 11, the condenser 10 is connected to the evaporation chamber 2, the condenser 10 is connected to the condensate tank 14 via the cooler 13, and the condensate tank 14 is connected to the vacuum pump 16. The refrigerant in the condenser 10 is located in the shell side, and the secondary vapor generated in the evaporation chamber 2 enters the tube side of the condenser 10. A feed valve 1 is installed on the feed line of the evaporation chamber 2. A first manual valve 5 is installed on the line connecting the subcooler 8 and the heater 3, and a second manual valve 6 and an electronic expansion valve 9 are sequentially installed on the line connecting the subcooler 8 and the condenser 10. A vacuum valve 15 is installed on the line connecting the condensate tank 14 and the vacuum pump 16. The condenser 10 is a falling film condenser.

[0025] Material enters evaporation chamber 2 through feed valve 1; material evaporates in evaporation chamber 2 to generate secondary steam; material is heated in heater 3; refrigerant enters subcooler 8 through first manual valve 5; refrigerant is fully liquefied in subcooler 8; refrigerant flows out of subcooler 8 through second manual valve 6 and flows to electronic expansion valve 9; electronic expansion valve 9 regulates refrigerant flow; refrigerant is heated and vaporized in condenser 10, refrigerant flows through shell side, secondary steam flows through tube side; compressor 11 compresses low-temperature, low-pressure gaseous refrigerant into high-temperature, high-pressure gaseous refrigerant; cooler 13 fully liquefies the vapor that could not be fully liquefied; condensate tank 14 is used to store condensate; vacuum pump 16 evacuates evaporation chamber 2 through condensate tank 14; vacuum pump 16 evacuates condensate tank 14 and evaporation chamber 2 through vacuum valve 15.

[0026] The operating steps of this utility model are as follows:

[0027] ① Heat Recovery: The material enters the evaporation chamber 2 through the feed valve 1. Inside the evaporation chamber 2, the material evaporates into secondary steam, which flows towards the condensate tank 14 under the action of the vacuum pump 16, passing through the tube side of the condenser 10. Inside the condenser 10, the low-temperature, low-pressure (exemplary, approximately 50°C, 7–12 bar) liquid refrigerant absorbs heat from the secondary steam and vaporizes, becoming a low-temperature, low-pressure (exemplary, approximately 50°C, 7–12 bar) gaseous refrigerant. Most of the secondary steam liquefies after absorbing heat. The vapor-liquid mixture enters the cooler 13, where it is completely liquefied into condensate, which then enters the condensate tank 14.

[0028] ②Increase enthalpy: Low-temperature, low-pressure gaseous refrigerant is drawn into compressor 11, and under the action of compressor 11, its temperature and pressure are increased, becoming high-temperature, high-pressure (for example, about 80°C, 18-22 bar) gaseous refrigerant.

[0029] ③ Heat Release: High-temperature, high-pressure gaseous refrigerant enters heater 3 and heats the material inside. After heat release, it becomes a high-temperature, high-pressure (for example, about 80°C, 18-22 bar) gas-liquid mixture of refrigerant. The material absorbs heat and its temperature rises, then it enters evaporation chamber 2 and evaporates into secondary steam.

[0030] ④ Subcooling: The high-temperature and high-pressure gas-liquid mixture refrigerant flowing out of heater 3 enters subcooler 8 through the first manual valve 5. In subcooler 8, it is completely liquefied into a high-temperature and high-pressure (exemplary, about 80°C, 18-22 bar) liquid refrigerant, and then flows to electronic expansion valve 9 through the second manual valve 6.

[0031] ⑤ Throttling: The high-temperature and high-pressure (exemplary, about 80°C, 18-22 bar) liquid refrigerant passes through the electronic expansion valve 9, and under its throttling effect, it becomes a low-temperature and low-pressure (about 50°C, 7-12 bar) liquid refrigerant, and then enters the shell side of the condenser 10.

[0032] ⑥The above process repeats continuously.

[0033] This utility model's condenser 10 is a falling film condenser, employing a refrigerant flow path through the shell and a secondary steam flow path through the tubes. The tube-side design of the falling film condenser, through "steam velocity control" and "flow direction optimization," maintains a relatively fast flow velocity of the secondary steam within the tubes. On one hand, the rapidly flowing steam exerts a "scouring force" on the tube walls, preventing condensate from remaining on the tube walls for extended periods. On the other hand, the liquid formed after the secondary steam condenses is quickly discharged along the steam flow direction, reducing the chances of "liquid retention → impurity adhesion → scaling." Simultaneously, the secondary steam is in contact with the tube walls—the outer side of the tube walls contains low-temperature refrigerant, so the tube wall temperature is much lower than the condensation temperature of the secondary steam, thus the secondary steam generally does not condense or form scale. Even if scale forms within the heat exchange tubes, because the heat exchange tubes are unobstructed (generally "hollow straight tubes"), cleaning fluid (or high-pressure water) can be directly introduced into the tubes during cleaning, flowing along the internal channels to complete the flushing.

[0034] Liquid refrigerant enters the shell side of condenser 10 from top to bottom. As it flows downwards along the tube wall under gravity, it continuously absorbs heat from the tube wall (the condensation heat of the secondary vapor in the tube side), gradually vaporizing into gaseous refrigerant. Since the density of gaseous refrigerant is much lower than that of liquid, it automatically flows upwards under buoyancy, exiting from the upper outlet of the condenser 10 shell side and entering the subsequent compressor 11. Liquid refrigerant flows downwards due to gravity and does not flow upwards; gaseous refrigerant flows upwards due to buoyancy and exits from the upper outlet. The two flow in completely opposite directions and have a clear "gas-liquid separation space" (the middle region of the shell side). The gaseous refrigerant does not come into contact with the liquid refrigerant at the bottom as it rises, preventing "gas-liquid entrainment." Ultimately, the refrigerant entering compressor 11 is in pure gaseous form, completely avoiding the risk of liquid slugging and protecting compressor 11.

[0035] Example 2:

[0036] This embodiment is an improvement on Embodiment 1. Specifically, the heater 3 is equipped with a refrigerant outlet pipe, and a safety valve 4 is installed on the refrigerant outlet pipe. An oil separator 12 is installed between the compressor 11 and the heater 3.

[0037] The safety valve 4 is designed to prevent the risk of overpressure in the heater 3, thus providing overpressure protection. For example, a preset opening pressure is set for the safety valve 4. When the pressure in the heater 3 does not exceed the preset opening pressure, the safety valve 4 closes; when the pressure in the heater 3 exceeds the preset opening pressure, the safety valve 4 opens to release pressure; and when the pressure in the heater 3 drops to a safe range (below the preset opening pressure or preset closing pressure), the safety valve 4 automatically closes.

[0038] Refrigeration oil (refrigeration unit oil) is an important material for the stable, efficient, and long-term operation of compressor 11. However, if refrigeration oil enters heat exchange components such as the evaporator and condenser, it will reduce the heat exchange efficiency. Therefore, an oil separator 12 is installed between compressor 11 and heater 3 to separate gaseous refrigerant from refrigeration oil, so that only gaseous refrigerant enters heater 3, thereby avoiding affecting the heat exchange efficiency.

[0039] Example 3:

[0040] This embodiment is an improvement based on embodiment 1 or embodiment 2. The specific improvement is that the end of the first manual valve 5 away from the subcooler 8 is connected to the end of the second manual valve 6 away from the subcooler 8 through the third manual valve 7, so that the third manual valve 7 and the subcooler 8 are connected.

[0041] The third manual valve 7 is connected in parallel with the subcooler 8 to accommodate different refrigerant phases, ensuring efficient refrigerant entry into the condenser 10. The refrigerant flowing from the heater 3 is typically a high-temperature, high-pressure gas-liquid mixture. After being fully liquefied by the subcooler 8, it enters the condenser 10 via the electronic expansion valve 9, thereby improving the refrigerant's heat absorption efficiency. When the refrigerant flowing from the heater 3 is gaseous or has a higher proportion of gaseous to liquid phases, it can also flow directly through the third manual valve 7 to the electronic expansion valve 9 before entering the condenser 10. Depending on the actual situation, the first manual valve 5 and the third manual valve 7 can be opened simultaneously, or only one of them can be opened.

[0042] Example 4:

[0043] This embodiment is an improvement based on Embodiment 1, Embodiment 2 or Embodiment 3. The specific improvement is that the heat of the secondary steam generated in the evaporation chamber 2 is greater than the heat absorbed by the refrigerant in the condenser 10.

[0044] The system employs redundant heat recovery control, ensuring that the heat generated by the secondary steam exceeds the heat absorbed by the refrigerant. This guarantees a sufficient heat source for the refrigerant and avoids heat mismatch caused by the physical properties of the materials themselves. Consequently, it ensures the stability of the equipment operation when evaporating non-aqueous materials, making it suitable for materials with various properties.

[0045] In this utility model, the use of words such as "a," "an," "a kind," and "the" does not indicate a quantity limitation and can represent singular or plural. The terms "comprising," "including," "having," and any variations thereof used in this utility model are intended to cover non-exclusive inclusion; the terms "first," "second," and "third" used in this utility model are merely to distinguish similar objects and do not represent a specific ordering of objects.

[0046] In this invention, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not exist between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may not be directly connected to the other devices but may have an intermediary device.

[0047] Furthermore, this utility model does not discuss in detail the technologies and equipment known to those skilled in the art, but where appropriate, such technologies and equipment should be considered part of the specification.

[0048] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the substantive content of this utility model. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An energy recovery system, characterized in that, It includes an evaporation chamber (2), a heater (3), a subcooler (8), a condenser (10), a compressor (11), a cooler (13), a condensate tank (14), and a vacuum pump (16); The evaporation chamber (2) is connected to the heater (3), the heater (3) is connected to the condenser (10) through the subcooler (8), the condenser (10) is connected to the heater (3) through the compressor (11), the condenser (10) is connected to the evaporation chamber (2), the condenser (10) is connected to the condensate tank (14) through the cooler (13), and the condensate tank (14) is connected to the vacuum pump (16); The refrigerant in the condenser (10) is placed in the shell side, and the secondary steam generated in the evaporator (2) enters the tube side of the condenser (10).

2. The energy recovery system according to claim 1, characterized in that, A feed valve (1) is installed on the feed pipe of the evaporation chamber (2).

3. The energy recovery system according to claim 1, characterized in that, The heater (3) is provided with a refrigerant outlet pipe, and a safety valve (4) is provided on the refrigerant outlet pipe.

4. The energy recovery system according to claim 1, characterized in that, A first manual valve (5) is provided on the pipeline connecting the subcooler (8) and the heater (3), and a second manual valve (6) and an electronic expansion valve (9) are provided in sequence on the pipeline connecting the subcooler (8) and the condenser (10).

5. The energy recovery system according to claim 4, characterized in that, The end of the first manual valve (5) away from the subcooler (8) is connected to the end of the second manual valve (6) away from the subcooler (8) through the third manual valve (7).

6. The energy recovery system according to claim 1, characterized in that, An oil separator (12) is provided between the compressor (11) and the heater (3).

7. The energy recovery system according to claim 1, characterized in that, A vacuum valve (15) is installed on the pipeline connecting the condensate tank (14) and the vacuum pump (16).

8. The energy recovery system according to claim 1, characterized in that, The condenser (10) is a falling film condenser.

9. The energy recovery system according to claim 1, characterized in that, The heat of the secondary steam generated in the evaporation chamber (2) is greater than the heat absorbed by the refrigerant in the condenser (10).

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