MVR (Mechanical Vapor Recompression) system with condensed water vaporization latent heat recovery function

Abstract

The invention discloses an MVR (Mechanical Vapor Recompression) system with condensed water vaporization latent heat recovery, which relates to the technical field of energy conservation and comprises a preheating device, an evaporation device and a compressor device, the preheating device comprises a first-stage preheater, a second-stage preheater and a condensation tank, and the evaporation device comprises a separator and a heater; a stock solution is preheated by a first-stage preheater and a second-stage preheater and then enters a separator for vapor-liquid separation, vapor separated by the separator is compressed by a compressor device, the temperature and pressure of the vapor are increased, enthalpy of the vapor is increased, the vapor is fed into a heater for secondary utilization, and liquid separated by the separator enters the heater for heating concentration; the condensation tank is communicated with the heater, high-temperature and high-pressure condensed water discharged by the heater enters the condensation tank, generated non-condensable gas enters the compressor device to be recompressed, the temperature and pressure of the non-condensable gas are increased, enthalpy is increased, and the non-condensable gas enters the heater to be reused; the latent heat of vaporization of the condensate water can be fully utilized, and energy consumption is greatly saved on the premise that investment is not increased.

Description

Technical Field

[0001] The invention relates to the technical field of energy saving, and in particular to an MVR system with condensed water vaporization latent heat recovery. Background Art

[0002] MVR (Mechanical Vapor Recompression) technology is an efficient energy-saving technology, mainly used in industrial evaporation processes. Its main working principle is to reuse the energy of the secondary steam generated by itself, thereby reducing the demand for external energy. However, the existing MVR system does not have a process flow for recycling the latent heat of condensed water vaporization, resulting in a certain degree of energy waste. The existing MVR system directly discharges the non-condensable gas generated after the high-temperature and high-pressure condensed water generated by the heat exchanger is introduced into the condensation tank for condensation, but does not utilize it.

[0003] Therefore, providing an MVR system that can fully utilize the latent heat of condensed water vaporization is a technical problem that those skilled in the art urgently need to solve. Summary of the invention

[0004] The purpose of the present invention is to provide an MVR system with condensed water vaporization latent heat recovery to solve the problems existing in the above-mentioned prior art, which can fully utilize the latent heat of vaporization of condensed water and achieve greater energy savings without increasing investment.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides an MVR system with condensed water vaporization latent heat recovery, comprising a preheating device, an evaporation device and a compressor device; the preheating device comprises a primary preheater, a secondary preheater and a condensing tank, and the evaporation device comprises a separator and a heater;

[0007] The primary preheater is connected to the secondary preheater, and the secondary preheater is connected to the separator. After the raw liquid is preheated by the primary preheater and the secondary preheater, it enters the separator for vapor-liquid separation. The vapor separated by the separator is compressed by the compressor device, and its temperature and pressure are increased, and the thermal enthalpy is increased. It is sent to the heater for secondary utilization, and the liquid separated by the separator enters the heater for heating and concentration;

[0008] The condensation tank is connected to the heater, and the high-temperature and high-pressure condensed water discharged from the heater enters the condensation tank. The generated non-condensable gas enters the compressor device for recompression, and its temperature and pressure are increased, and the thermal enthalpy is increased, and then enters the heater for reuse.

[0009] Preferably, a raw liquid inlet pipeline is provided between the first-stage preheater and the raw liquid inlet, and a raw material pump is provided on the raw liquid inlet pipeline for providing power to the raw liquid entering the preheating device.

[0010] Preferably, a non-condensable gas pipeline is provided between the secondary preheater and the non-condensable gas outlet, and a vacuum pump is provided on the non-condensable gas pipeline for providing power to the non-condensable gas of the exhaust system.

[0011] Preferably, the heater is connected to the secondary preheater and the separator respectively, the steam generated in the heater enters the secondary preheater for heating and then is discharged from the system, and the concentrated raw liquid heated by the heater enters the separator again, and the steam-liquid separation is performed again through the separator.

[0012] Preferably, a circulation pipeline is provided between the lower liquid inlet end of the heater and the liquid outlet end of the separator, and a strong circulation pump is provided on the circulation pipeline to provide power to the liquid in the heater.

[0013] Preferably, a condensate pipe is provided between the heater and the condensation tank, and a steam trap is provided on the condensate pipe for discharging condensate in the heater and preventing steam from passing through.

[0014] Preferably, a condensate water pipeline is provided between the condensate tank and the primary preheater, and a condensate water pump is provided on the condensate water pipeline to provide power for the condensate water entering the primary preheater.

[0015] Preferably, the high-temperature and high-pressure condensed water discharged from the heater enters the condensation tank, and after being fully condensed, the low-pressure condensed water enters the primary preheater for heating and then is discharged.

[0016] Preferably, the gas separated by the separator and the non-condensable gas produced by the condenser enter the compressor device through a steam pipeline.

[0017] Compared with the prior art, the present invention has achieved the following technical effects:

[0018] The present invention can recover the non-condensable gas re-formed in the condensing tank due to the heat release of the condensed water, and connect it to the steam pipeline connecting the separator and the compressor device. Without increasing the complexity of the system, it enters the compressor device together with the steam separated by the separator for compression, so that its temperature and pressure are increased, the thermal enthalpy is increased, and it is sent to the heater for secondary utilization. Compared with the traditional MVR system, the present invention makes full use of the latent heat of vaporization of the condensed water, and achieves greater energy savings without increasing investment. According to calculations, it saves more than 3.5% to 5% of energy consumption compared with the traditional MVR system. The larger the processing volume, the more obvious the effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a structural schematic diagram of the MVR system with condensed water vaporization latent heat recovery in the present invention;

[0021] In the figure: 1. preheating device; 2. evaporation device; 3. compressor device; 11. primary preheater; 12. secondary preheater; 13. condenser; 21. separator; 22. heater; 31. vacuum pump; 32. raw material pump; 33. condensate pump; 34. strong circulation pump; 35. discharge pump; 51. circulation pipeline; 52. raw liquid inlet pipeline; 53. non-condensable gas pipeline; 54. condensate pipeline; 55. drain pipeline; 56. discharge pipeline; 57. steam pipeline; 71. drain valve. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The object of the present invention is to provide an MVR system with condensed water vaporization latent heat recovery to solve the problems existing in the prior art.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] In this embodiment, an MVR system with condensed water vaporization latent heat recovery is provided. Figure 1 As shown, it includes a preheating device 1, an evaporating device 2 and a compressor device 3; the preheating device 1 includes a primary preheater 11, a secondary preheater 12 and a condensing tank 13, and the evaporating device 2 includes a separator 21 and a heater 22;

[0026] The primary preheater 11 is connected to the secondary preheater 12, and the secondary preheater 12 is connected to the separator 21. After the raw liquid is preheated by the primary preheater 11 and the secondary preheater 12, it enters the separator 21 for vapor-liquid separation. The vapor separated by the separator 21 is compressed by the compressor device 3, and its temperature and pressure are increased, and the thermal enthalpy is increased. It is sent to the heater 22 for secondary utilization, and the liquid separated by the separator 21 enters the heater 22 for heating and concentration;

[0027] The condensation tank 13 is connected to the heater 22. The high-temperature and high-pressure condensed water discharged from the heater 22 enters the condensation tank 13. The generated non-condensable gas enters the compressor device 3 for recompression. Its temperature and pressure increase, and its thermal enthalpy increases, and it enters the heater 22 for reuse.

[0028] In this specific embodiment, a raw liquid inlet pipeline 52 is provided between the first-stage preheater 11 and the raw liquid inlet, and a raw material pump 32 is provided on the raw liquid inlet pipeline 52 for providing power to the raw liquid entering the preheating device 1 .

[0029] In this specific embodiment, a non-condensable gas pipeline 53 is provided between the secondary preheater 12 and the non-condensable gas outlet, and a vacuum pump 31 is provided on the non-condensable gas pipeline 53 to provide power for the non-condensable gas of the exhaust system.

[0030] In this specific embodiment, the heater 22 is connected to the secondary preheater 12 and the separator 21 respectively. The steam generated in the heater 22 enters the secondary preheater 12 for heating and then is discharged from the system. The concentrated raw liquid heated by the heater 22 enters the separator 21 again, and the vapor-liquid separation is performed again through the separator 21.

[0031] In this specific embodiment, a circulation pipe 51 is provided between the lower liquid inlet end of the heater 22 and the liquid outlet end of the separator 21 , and a strong circulation pump 34 is provided on the circulation pipe 51 for providing power to the liquid in the heater 22 .

[0032] In this specific embodiment, a discharge pipe 56 is provided between the separator 21 and the strong circulation pump 34 , and a discharge pump 35 is provided on the discharge pipe 56 to provide power for the discharge system of the concentrated raw liquid.

[0033] In this specific embodiment, a condensate pipe 54 is provided between the heater 22 and the condensation tank 13 , and a steam trap 71 is provided on the condensate pipe 54 for discharging condensate in the heater 22 and preventing steam from passing through.

[0034] In this specific embodiment, a condensate pipe 54 is provided between the condensate tank 13 and the primary preheater 11 , and a condensate pump 33 is provided on the condensate pipe 54 to provide power for the condensate entering the primary preheater 11 .

[0035] In this specific embodiment, the high-temperature and high-pressure condensed water discharged from the heater 22 enters the condensation tank 13. After being fully condensed, the low-pressure condensed water enters the primary preheater 11 and is heated before being discharged.

[0036] In this specific embodiment, the gas separated by the separator 21 and the non-condensable gas produced by the condenser 13 enter the compressor device 3 through the steam pipeline 57 .

[0037] The working principle of the present invention is as follows:

[0038] The raw liquid flows in from the raw liquid inlet pipe 52, powered by the raw material pump 32 on the raw liquid inlet pipe 52, and is preheated in turn by the primary preheater 11 and the secondary preheater 12. After being preheated, the raw liquid enters the separator 21 for vapor-liquid separation. The liquid separated by the separator 21 flows into the circulation pipe 51, powered by the strong circulation pump 34 on the circulation pipe 51, flows in from the lower liquid inlet end of the heater 22, and continues to be heated and concentrated in the heater 22. The separator 21, the heater 22, the strong circulation pump 34 and the circulation pipe 51 constitute a circulation pipeline. The raw liquid is continuously circulated, heated and concentrated on this circulation pipe until the concentrated liquid reaches the required concentration and flows into the discharge pipe 56. At this time, the discharge pump 35 on the discharge pipe 56 provides power to support the concentrated liquid reaching the required concentration to flow out of the system. The gas part separated by the separator 21 enters the compressor device 3 for compression, and its temperature and pressure are increased, and the thermal enthalpy increases, and then enters from the side air inlet end of the heater 22 to provide heat for the operation of the heater 22.

[0039] Furthermore, the heater 22 continuously generates steam and condensed water in the process of heating the raw liquid. The generated steam flows into the steam pipe 53, is heated by the secondary preheater 12, and then is powered by the vacuum pump 31 on the steam pipe 53 to discharge the generated steam from the system. The high-temperature and high-pressure condensed water generated in the heater 22 enters the drain pipe 54, and a drain valve 71 is provided on the drain pipe 55. The drain valve 71 controls the outflow of condensed water and prevents the passage of steam.

[0040] Furthermore, the high-temperature and high-pressure condensed water in the heater 22 flows into the condensation tank 13 through the drain pipe 54. The high-temperature and high-pressure condensed water releases a large amount of heat in the low-pressure environment entering the condensation tank 13, and this part of the heat reheats another part of the condensed water into steam. In some embodiments, the steam generated in the condensation equipment is directly discharged from the system without being used, which results in a large loss of latent heat of vaporization of the condensed water. In this embodiment, the steam generated in the condensation tank 13 is connected to the steam pipe 57, and enters the compression device 3 together with the steam separated by the separator 21 for compression, and then enters the heater 22 for reuse. The latent heat of vaporization of the condensed water in the condensation tank 13 is utilized without increasing the complexity of the system. This saves investment and further increases the utilization rate of energy.

[0041] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An MVR system with condensed water vaporization latent heat recovery, characterized in that: It includes a preheating device, an evaporating device and a compressor device; the preheating device includes a primary preheater, a secondary preheater and a condensing tank, and the evaporating device includes a separator and a heater; The primary preheater is connected to the secondary preheater, and the secondary preheater is connected to the separator. After the raw liquid is preheated by the primary preheater and the secondary preheater, it enters the separator for vapor-liquid separation. The vapor separated by the separator is compressed by the compressor device, and its temperature and pressure are increased, and the thermal enthalpy is increased. It is sent to the heater for secondary utilization, and the liquid separated by the separator enters the heater for heating and concentration; The condensation tank is connected to the heater, and the high-temperature and high-pressure condensed water discharged from the heater enters the condensation tank. The generated non-condensable gas enters the compressor device for recompression, and its temperature and pressure are increased, and the thermal enthalpy is increased, and then enters the heater for reuse.

2. The MVR system with condensed water vaporization latent heat recovery according to claim 1, characterized in that: A raw liquid inlet pipeline is provided between the first-stage preheater and the raw liquid inlet, and a raw material pump is provided on the raw liquid inlet pipeline for providing power to the raw liquid entering the preheating device.

3. The MVR system with condensed water vaporization latent heat recovery according to claim 1, characterized in that: A non-condensable gas pipeline is provided between the secondary preheater and the non-condensable gas outlet, and a vacuum pump is provided on the non-condensable gas pipeline for providing power to the non-condensable gas of the exhaust system.

4. The MVR system with condensed water vaporization latent heat recovery according to claim 1, characterized in that: The heater is connected to the secondary preheater and the separator respectively. The steam generated in the heater enters the secondary preheater for heating and then is discharged from the system. The concentrated raw liquid heated by the heater enters the separator again and is separated into vapor and liquid again through the separator.

5. The MVR system with condensed water vaporization latent heat recovery according to claim 4, characterized in that: A circulation pipeline is provided between the lower liquid inlet end of the heater and the liquid outlet end of the separator, and a strong circulation pump is provided on the circulation pipeline to provide power to the liquid in the heater.

6. The MVR system with condensed water vaporization latent heat recovery according to claim 5, characterized in that: A discharge pipeline is provided between the separator and the strong circulation pump, and a discharge pump is provided on the discharge pipeline to provide power for the discharge system of the concentrated raw liquid.

7. The MVR system with condensed water vaporization latent heat recovery according to claim 1, characterized in that: A condensate pipe is provided between the heater and the condensation tank, and a steam trap is provided on the condensate pipe for discharging condensate in the heater and preventing steam from passing through.

8. The MVR system with condensed water vaporization latent heat recovery according to claim 1, characterized in that: A condensate water pipeline is provided between the condensate tank and the primary preheater, and a condensate water pump is provided on the condensate water pipeline to provide power for the condensate water entering the primary preheater.

9. The MVR system with condensed water vaporization latent heat recovery according to claim 1, characterized in that: The high-temperature and high-pressure condensed water discharged from the heater enters the condensation tank, and after being fully condensed, the low-pressure condensed water enters the primary preheater for heating and then is discharged.

10. The MVR system with condensed water vaporization latent heat recovery according to claim 1, characterized in that: The gas separated by the separator and the non-condensable gas produced by the condenser enter the compressor device through a steam pipeline.

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