阅读说明：本技术 一种两效蒸发器及其使用方法 (Double-effect evaporator and using method thereof ) 是由 韩东 李春霞 顾杨怡 于 2019-11-19 设计创作，主要内容包括：本发明公开了一种两效蒸发器及其使用方法,包含多个基础板片,每个基础板片的两面分别为A面和B面,多个基础板片在蒸发器内堆叠并且A面和B面交替设置；相邻基础板片的A面与A面之间的板片通道包含由下至上依次设置的一效溶液蒸发区、一效气液分离区、二效溶液蒸发区、二效气液分离区和二效蒸汽冷凝放热区；相邻基础板片的B面与B面之间的板片通道包含由下至上依次设置的热源放热区、一效气液分离区、一效蒸汽冷凝放热区、二效气液分离区和冷源吸热区；A面与A面之间的板片通道的五个区域与A面与A面之间的板片通道的五个区域构成五个一一对应的界面关系。本发明实现对稀溶液的温度梯级蒸发冷凝,二效蒸发器换热系数高、结构紧凑。(The invention discloses a double-effect evaporator and a using method thereof, and the double-effect evaporator comprises a plurality of base plate sheets, wherein the two surfaces of each base plate sheet are respectively an A surface and a B surface, the base plate sheets are stacked in the evaporator, and the A surfaces and the B surfaces are alternately arranged; the plate channel between the surface A and the surface A of the adjacent base plates comprises a first-effect solution evaporation area, a first-effect gas-liquid separation area, a second-effect solution evaporation area, a second-effect gas-liquid separation area and a second-effect steam condensation heat release area which are sequentially arranged from bottom to top; the plate channel between the surface B and the surface B of the adjacent base plate comprises a heat source heat release area, a first-effect gas-liquid separation area, a first-effect steam condensation heat release area, a second-effect gas-liquid separation area and a cold source heat absorption area which are sequentially arranged from bottom to top; five areas of the plate channel between the surface A and five areas of the plate channel between the surface A and the surface A form five one-to-one corresponding interface relations. The invention realizes the temperature gradient evaporation and condensation of the dilute solution, and the double-effect evaporator has high heat exchange coefficient and compact structure.)

1. A two-effect evaporator is characterized in that: the evaporator comprises a plurality of base plates, wherein the two surfaces of each base plate are respectively an A surface and a B surface, the base plates are stacked in the evaporator, and the A surfaces and the B surfaces are alternately arranged;

the plate channel between the surface A and the surface A of the adjacent base plates comprises a first-effect solution evaporation area, a first-effect gas-liquid separation area, a second-effect solution evaporation area, a second-effect gas-liquid separation area and a second-effect steam condensation heat release area which are sequentially arranged from bottom to top;

the plate channel between the surface B and the surface B of the adjacent base plate comprises a heat source heat release area, a first-effect gas-liquid separation area, a first-effect steam condensation heat release area, a second-effect gas-liquid separation area and a cold source heat absorption area which are sequentially arranged from bottom to top;

five areas of the plate channel between the surface A and five areas of the plate channel between the surface A and the surface A form five one-to-one corresponding interface relations.

2. A two-effect evaporator according to claim 1 wherein: the foundation plate is provided with a cold source inlet, a cold source outlet, two-effect steam holes, two-effect dilute solution inlets, one-effect steam holes, one-effect condensate outlets, one-effect dilute solution inlets, one-effect concentrated solution outlets, heat source inlets, heat source outlets, one-effect gas-liquid overflow outlets, two-effect concentrated solution outlets, two-effect gas-liquid overflow outlets and two-effect condensate outlets, wherein the cold source inlet and the cold source outlets, the two-effect condensate outlets, the two-effect gas-liquid overflow outlets, the two-effect concentrated solution outlets, the one-effect condensate outlets, the one-effect gas-liquid overflow outlets, the heat source outlets and the heat source inlets are sequentially arranged from top to bottom, the upper positions and the lower positions of the cold source inlet and the cold source outlet are not limited, the two groups of two-effect steam holes are respectively arranged on the two sides of the cold source inlet and the cold source outlet, the two groups of two-effect dilute solution inlets and the two groups of one-effect steam holes are respectively arranged on the two sides of the area between the two-effect concentrated solution outlets and the two groups of one-effect dilute solution inlets are respectively arranged at two sides of the heat source inlet and the heat source outlet;

the surface A of the base plate is further provided with a double-effect condensate collecting gasket, a high-low pressure partition gasket, a heat source inlet-outlet partition gasket, a cold source inlet-outlet partition gasket, a double-effect dilute solution inlet-shunt gasket and a first-effect dilute solution inlet-shunt gasket, the middle part of the double-effect condensate collecting gasket is surrounded on the lower side of a double-effect condensate outlet, two side edges of the double-effect condensate collecting gasket extend to the lower side of the inner side of a double-effect steam hole, the high-low pressure partition gasket sequentially passes through the space between a group of double-effect dilute solution inlets and a group of double-effect steam holes from one side edge of the base plate, the space between a first-effect condensate outlet and a double-effect concentrated solution outlet, the space between the other group of double-effect dilute solution inlets and a group of single-effect steam holes and finally extends to the other side edge of the base plate, the heat source inlet-outlet partition gasket surrounds the outer sides of the heat source inlet and the heat source outlet and separates The two-effect dilute solution inlet shunting gasket surrounds the outer side of the two-effect dilute solution inlet, and the one-effect dilute solution inlet shunting gasket surrounds the outer side of the one-effect dilute solution inlet;

the surface B of the foundation slab is also provided with a cold source partitioning gasket, a double-effect dilute solution inlet isolating gasket, a single-effect concentrated solution outlet gasket, a heat source runner partitioning gasket, a heat source partitioning gasket, a single-effect condensate collecting gasket, a double-effect low-pressure area isolating gasket and a cold source runner partitioning gasket, the cold source partitioning gasket sequentially passes through the inner side of a group of double-effect steam holes from the upper side edge of the foundation slab, between the cold source outlet and the double-effect condensate outlet and extends to the upper side edge of the foundation slab after passing through the inner side of the other group of double-effect steam holes, the double-effect dilute solution inlet isolating gasket surrounds the outer side of the double-effect dilute solution inlet, the single-effect dilute solution inlet isolating gasket surrounds the outer side of the single-effect dilute solution inlet, the single-effect concentrated solution outlet gasket surrounds the outer side of the single-effect concentrated solution outlet, the heat source runner partitioning gasket is arranged between the heat source inlet and the heat source Piece both sides border, one imitate the lime set and collect the gasket and surround in one imitate lime set export downside and both ends extend to one respectively and imitate the inboard below of steam hole, two imitate low-pressure area isolation gasket surround in two imitate concentrated solution export outsides and two imitate low-pressure area isolation gasket both ends tip upwards extend to two imitate gas-liquid overflow export downside backward both sides extend to the both sides border of basic slab in two imitate concentrated solution export tops, cold source runner subregion gasket sets up between cold source import and cold source export.

3. A two-effect evaporator according to claim 2 wherein: the primary solution evaporation area is an area below a primary gas-liquid overflow outlet; the first-effect gas-liquid separation area is an area between the gaskets of the high-pressure and low-pressure subareas above the first-effect gas-liquid overflow port; the two-effect solution evaporation area is an area between the high-low pressure partition gasket and the two-effect gas-liquid overflow port, and the two-effect gas-liquid separation area is an area between the two-effect gas-liquid overflow port and the two-effect condensate collection gasket; the secondary steam condensation heat release area is an area above the secondary condensate collecting gasket;

the heat source heat release area is an area below the first-effect gas-liquid overflow outlet, the first-effect gas-liquid separation area is an area between the first-effect gas-liquid overflow outlet and the first-effect condensate collection gasket, and the first-effect steam condensation heat release area is an area between the first-effect condensate collection gasket and the second-effect low-pressure area separation gasket; the secondary-effect gas-liquid separation zone is a zone between the secondary-effect low-pressure zone isolation gasket and the cold source partition gasket; the cold source heat absorption area is the area inside the cold source partition gasket.

4. A two-effect evaporator according to claim 2 wherein: the cold source inlet, the cold source outlet, the double-effect steam hole, the double-effect dilute solution inlet, the single-effect steam hole, the single-effect condensate outlet, the single-effect dilute solution inlet, the single-effect concentrated solution outlet, the heat source inlet, the heat source outlet, the single-effect gas-liquid overflow outlet, the double-effect concentrated solution outlet, the double-effect gas-liquid overflow outlet and the double-effect condensate outlet are provided with one or more round, square or special-shaped openings.

5. A two-effect evaporator according to claim 2 wherein: one or more gaps or holes are arranged on the first-effect dilute solution inlet shunting gasket and the second-effect dilute solution inlet shunting gasket, and diversion trenches are arranged at the first-effect dilute solution inlet and the second-effect dilute solution inlet.

6. A two-effect evaporator according to claim 2 wherein: before use, the space between the two-effect condensate outlet and the one-effect condensate outlet and the space communicated with the two-effect condensate outlet are vacuumized, and the vacuum degree of the two-effect condensate outlet is higher than that of the one-effect condensate outlet.

7. A two-effect evaporator according to claim 2 wherein: the dilute solution to be evaporated and concentrated is used as a cold source, the dilute solution firstly enters the inlet of the cold source to absorb heat and then is discharged from the outlet of the cold source, and the discharged dilute solution enters the first-effect dilute solution inlet and the second-effect dilute solution inlet.

8. A two-effect evaporator according to claim 2 wherein: the working medium at the outlet of the first-effect concentrated solution is used as the working medium at the inlet of the second-effect dilute solution.

9. A two-effect evaporator according to claim 1 wherein: the heat source adopts steam or high-temperature liquid and gaseous working medium, and the temperature is higher than 60 ℃.

10. A method of using the two-effect evaporator of any one of claims 1-9, comprising the steps of:

the method comprises the following steps: the external dilute solution enters a one-effect solution evaporation area, partial evaporation is carried out after the external dilute solution absorbs the heat energy released by a heat source heat release area on the back of the one-effect solution evaporation area, and the non-evaporated concentrated solution enters a one-effect concentrated solution outlet through the one-effect solution evaporation area and a one-effect gas-liquid overflow outlet respectively;

step two: the evaporated steam enters the first-effect gas-liquid separation area and the first-effect gas-liquid separation area through the first-effect gas-liquid overflow outlet respectively, then enters the first-effect steam condensation heat release area through the first-effect steam hole, releases latent heat to the low-pressure solution in the second-effect solution evaporation area, is condensed into condensate, and is discharged out of the system through the first-effect condensate outlet;

step three: the low-pressure solution in the double-effect solution evaporation area absorbs heat and then is partially evaporated, and the non-evaporated concentrated solution enters a double-effect concentrated solution outlet through the double-effect solution evaporation area and the double-effect gas-liquid overflow outlet respectively;

step four: the evaporated double-effect steam enters the double-effect gas-liquid separation area and the double-effect gas-liquid separation area through the double-effect gas-liquid overflow outlet respectively, then enters the double-effect steam condensation heat release area through the double-effect steam hole, releases latent heat to the cold source, is condensed into condensate, and is discharged out of the system from the double-effect condensate outlet.

Technical Field

The invention relates to an evaporator and a using method thereof, in particular to a dual-effect evaporator and a using method thereof, belonging to the field of energy and power.

Background

The solution evaporation and concentration device is indispensable technical equipment in multiple fields of chemical industry, food, medicine and the like at present, and can be mainly divided into a thermal method and a membrane method according to the working principle of the device, wherein the multi-effect evaporation technology is an important method of the thermal method.

At present, the multi-effect solution evaporation and concentration device is widely applied to a plurality of industries such as chemical industry, food, medicine and the like. However, the conventional multi-effect evaporation system has the main problems of high hardware cost and poor operation stability due to the large number of devices, large occupied space of the devices and complicated pipelines connected among the devices.

The plate heat exchanger is a common efficient compact heat exchanger, not only can be used for heating and cooling single-phase liquid working medium, but also can be used for evaporating the liquid working medium and condensing the gaseous working medium, and the plate heat exchanger can separate a cold source, a heat source and an evaporation interval by adding different-shaped gaskets between plates. And the plate is convenient to disassemble and clean, and the heat exchange capacity can be adjusted by adopting different plate numbers. Therefore, the plate heat exchanger is developed to be used as an evaporator for solution evaporation and concentration, and has important social application value.

Disclosure of Invention

The invention aims to provide a two-effect evaporator and a using method thereof, and the two-effect evaporator is compact in structure and simple in connection.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a two-effect evaporator is characterized in that: the evaporator comprises a plurality of base plates, wherein the two surfaces of each base plate are respectively an A surface and a B surface, the base plates are stacked in the evaporator, and the A surfaces and the B surfaces are alternately arranged;

the plate channel between the surface A and the surface A of the adjacent base plates comprises a first-effect solution evaporation area, a first-effect gas-liquid separation area, a second-effect solution evaporation area, a second-effect gas-liquid separation area and a second-effect steam condensation heat release area which are sequentially arranged from bottom to top;

the plate channel between the surface B and the surface B of the adjacent base plate comprises a heat source heat release area, a first-effect gas-liquid separation area, a first-effect steam condensation heat release area, a second-effect gas-liquid separation area and a cold source heat absorption area which are sequentially arranged from bottom to top;

five areas of the plate channel between the surface A and five areas of the plate channel between the surface A and the surface A form five one-to-one corresponding interface relations.

Further, the base plate is provided with a cold source inlet, a cold source outlet, two-effect steam holes, two-effect dilute solution inlet, one-effect steam hole, one-effect condensate outlet, one-effect dilute solution inlet, one-effect concentrated solution outlet, a heat source inlet, a heat source outlet, one-effect gas-liquid overflow outlet, two-effect concentrated solution outlet, two-effect gas-liquid overflow outlet and two-effect condensate outlet, wherein the cold source inlet and the cold source outlet, the two-effect condensate outlet, the two-effect gas-liquid overflow outlet, the two-effect concentrated solution outlet, the one-effect condensate outlet, the one-effect gas-liquid overflow outlet, the heat source outlet and the heat source inlet are sequentially arranged from top to bottom, the upper positions and the lower positions of the cold source inlet and the cold source outlet are not limited, the upper positions and the lower positions of the heat source outlet and the heat source inlet are not limited, the two groups of two-effect steam holes are respectively arranged on the two sides of the cold source inlet and the cold source outlet, the two groups of two-effect dilute solution inlet and two groups of one-effect dilute solution inlets are respectively arranged at two sides of the heat source inlet and the heat source outlet;

the surface A of the base plate is further provided with a double-effect condensate collecting gasket, a high-low pressure partition gasket, a heat source inlet-outlet partition gasket, a cold source inlet-outlet partition gasket, a double-effect dilute solution inlet-shunt gasket and a first-effect dilute solution inlet-shunt gasket, the middle part of the double-effect condensate collecting gasket is surrounded on the lower side of a double-effect condensate outlet, two side edges of the double-effect condensate collecting gasket extend to the lower side of the inner side of a double-effect steam hole, the high-low pressure partition gasket sequentially passes through the space between a group of double-effect dilute solution inlets and a group of double-effect steam holes from one side edge of the base plate, the space between a first-effect condensate outlet and a double-effect concentrated solution outlet, the space between the other group of double-effect dilute solution inlets and a group of single-effect steam holes and finally extends to the other side edge of the base plate, the heat source inlet-outlet partition gasket surrounds the outer sides of the heat source inlet and the heat source outlet and separates The two-effect dilute solution inlet shunting gasket surrounds the outer side of the two-effect dilute solution inlet, and the one-effect dilute solution inlet shunting gasket surrounds the outer side of the one-effect dilute solution inlet;

the surface B of the foundation slab is also provided with a cold source partitioning gasket, a double-effect dilute solution inlet isolating gasket, a single-effect concentrated solution outlet gasket, a heat source runner partitioning gasket, a heat source partitioning gasket, a single-effect condensate collecting gasket, a double-effect low-pressure area isolating gasket and a cold source runner partitioning gasket, the cold source partitioning gasket sequentially passes through the inner side of a group of double-effect steam holes from the upper side edge of the foundation slab, between the cold source outlet and the double-effect condensate outlet and extends to the upper side edge of the foundation slab after passing through the inner side of the other group of double-effect steam holes, the double-effect dilute solution inlet isolating gasket surrounds the outer side of the double-effect dilute solution inlet, the single-effect dilute solution inlet isolating gasket surrounds the outer side of the single-effect dilute solution inlet, the single-effect concentrated solution outlet gasket surrounds the outer side of the single-effect concentrated solution outlet, the heat source runner partitioning gasket is arranged between the heat source inlet and the heat source Piece both sides border, one imitate the lime set and collect the gasket and surround in one imitate lime set export downside and both ends extend to one respectively and imitate the inboard below of steam hole, two imitate low-pressure area isolation gasket surround in two imitate concentrated solution export outsides and two imitate low-pressure area isolation gasket both ends tip upwards extend to two imitate gas-liquid overflow export downside backward both sides extend to the both sides border of basic slab in two imitate concentrated solution export tops, cold source runner subregion gasket sets up between cold source import and cold source export.

Further, the first-effect solution evaporation area is an area below the first-effect gas-liquid overflow outlet; the first-effect gas-liquid separation area is an area between the gaskets of the high-pressure and low-pressure subareas above the first-effect gas-liquid overflow port; the two-effect solution evaporation area is an area between the high-low pressure partition gasket and the two-effect gas-liquid overflow port, and the two-effect gas-liquid separation area is an area between the two-effect gas-liquid overflow port and the two-effect condensate collection gasket; the secondary steam condensation heat release area is an area above the secondary condensate collecting gasket;

the heat source heat release area is an area below the first-effect gas-liquid overflow outlet, the first-effect gas-liquid separation area is an area between the first-effect gas-liquid overflow outlet and the first-effect condensate collection gasket, and the first-effect steam condensation heat release area is an area between the first-effect condensate collection gasket and the second-effect low-pressure area separation gasket; the secondary-effect gas-liquid separation zone is a zone between the secondary-effect low-pressure zone isolation gasket and the cold source partition gasket; the cold source heat absorption area is the area inside the cold source partition gasket.

Furthermore, the cold source inlet, the cold source outlet, the two-effect steam hole, the two-effect dilute solution inlet, the one-effect steam hole, the one-effect condensate outlet, the one-effect dilute solution inlet, the one-effect concentrated solution outlet, the heat source inlet, the heat source outlet, the one-effect gas-liquid overflow outlet, the two-effect concentrated solution outlet, the two-effect gas-liquid overflow outlet and the two-effect condensate outlet adopt one or more round, square or special-shaped holes.

Furthermore, one or more gaps or holes are arranged on the first-effect dilute solution inlet shunting gasket and the second-effect dilute solution inlet shunting gasket, and diversion trenches are arranged at the first-effect dilute solution inlet and the second-effect dilute solution inlet.

Further, before the vacuum-pumping device is used, the space communicated with the secondary effect condensate outlet, the primary effect condensate outlet and the secondary effect condensate outlet is vacuumized, and the vacuum degree of the secondary effect condensate outlet is higher than that of the primary effect condensate outlet.

Furthermore, dilute solution to be evaporated and concentrated is used as a cold source, the dilute solution firstly enters the inlet of the cold source to absorb heat and then is discharged from the outlet of the cold source, and the discharged dilute solution enters the first-effect dilute solution inlet and the second-effect dilute solution inlet.

Further, the working medium at the outlet of the first-effect concentrated solution is used as the working medium at the inlet of the second-effect dilute solution.

Furthermore, the heat source adopts steam or high-temperature liquid and gaseous working medium, and the temperature of the working medium is higher than 60 ℃.

A method of using a two-effect evaporator, comprising the steps of:

the method comprises the following steps: the external dilute solution enters a one-effect solution evaporation area, partial evaporation is carried out after the external dilute solution absorbs the heat energy released by a heat source heat release area on the back of the one-effect solution evaporation area, and the non-evaporated concentrated solution enters a one-effect concentrated solution outlet through the one-effect solution evaporation area and a one-effect gas-liquid overflow outlet respectively;

step two: the evaporated steam enters the first-effect gas-liquid separation area and the first-effect gas-liquid separation area through the first-effect gas-liquid overflow outlet respectively, then enters the first-effect steam condensation heat release area through the first-effect steam hole, releases latent heat to the low-pressure solution in the second-effect solution evaporation area, is condensed into condensate, and is discharged out of the system through the first-effect condensate outlet;

step three: the low-pressure solution in the double-effect solution evaporation area absorbs heat and then is partially evaporated, and the non-evaporated concentrated solution enters a double-effect concentrated solution outlet through the double-effect solution evaporation area and the double-effect gas-liquid overflow outlet respectively;

step four: the evaporated double-effect steam enters the double-effect gas-liquid separation area and the double-effect gas-liquid separation area through the double-effect gas-liquid overflow outlet respectively, then enters the double-effect steam condensation heat release area through the double-effect steam hole, releases latent heat to the cold source, is condensed into condensate, and is discharged out of the system from the double-effect condensate outlet.

Compared with the prior art, the invention has the following advantages and effects: the double-effect evaporator has the advantages that the using function of the double-effect evaporator is realized through the fin type structure similar to a plate type heat exchanger, the whole structure is efficient and compact, no complex connecting pipeline is needed, the occupied space is small, the double-effect evaporator can be applied to areas with higher requirements on space, such as ships and the like, and the double-effect evaporator has good application prospect; and secondly, the effect of solution evaporation and concentration is further improved through a two-effect design.

Drawings

FIG. 1 is a schematic view of the base plate A of a two-effect evaporator of the present invention.

Fig. 2 is a schematic view of the B-side of the base plate of a two-effect evaporator of the present invention.

FIG. 3 is a side A effect diagram of a method of using a dual effect evaporator of an embodiment of the present invention.

FIG. 4 is a B-side effect diagram of a method of using a two-effect evaporator of an embodiment of the present invention.

Detailed Description

The present invention is further illustrated by the following examples, which are illustrative of the present invention and are not to be construed as being limited thereto.

As shown in fig. 1 and 2, a two-effect evaporator of the present invention comprises a plurality of base plates 5, each base plate 5 having a side a and a side B on both sides, the plurality of base plates 5 being stacked in the evaporator and the sides a and B being alternately arranged;

the plate channel between the surface A and the surface A of the adjacent base plates comprises a first-effect solution evaporation area, a first-effect gas-liquid separation area, a second-effect solution evaporation area, a second-effect gas-liquid separation area and a second-effect steam condensation heat release area which are sequentially arranged from bottom to top;

the plate channel between the surface B and the surface B of the adjacent base plate comprises a heat source heat release area, a first-effect gas-liquid separation area, a first-effect steam condensation heat release area, a second-effect gas-liquid separation area and a cold source heat absorption area which are sequentially arranged from bottom to top;

five areas of the plate channel between the surface A and five areas of the plate channel between the surface A and the surface A form five one-to-one corresponding interface relations.

The base plate 5 is provided with a cold source inlet 1, a cold source outlet 2, a double-effect steam hole 4, a double-effect dilute solution inlet 7, a single-effect steam hole 8, a single-effect condensate outlet 9, a single-effect dilute solution inlet 11, a single-effect concentrated solution outlet 12, a heat source inlet 14, a heat source outlet 15, a single-effect gas-liquid overflow outlet 18, a double-effect concentrated solution outlet 20, a double-effect gas-liquid overflow outlet 22 and a double-effect condensate outlet 23, wherein the cold source inlet 1 and the cold source outlet 2, the double-effect condensate outlet 23, the double-effect gas-liquid overflow outlet 22, the double-effect concentrated solution outlet 20, the single-effect condensate outlet 9, the single-effect gas-liquid overflow outlet 18, the heat source outlet 15 and the heat source inlet 14 are sequentially arranged from top to bottom, the upper and lower positions of the cold source inlet 1 and the cold source outlet 2 are not limited, the upper and lower positions of the heat source outlet 15 and the heat source inlet 14 are not, the two groups of two-effect dilute solution inlets 7 and the two groups of one-effect steam holes 8 are respectively arranged at two sides of the area between the two-effect concentrated solution outlet 20 and the two-effect gas-liquid overflow outlet 22, the two-effect dilute solution inlets 7 are positioned at the inner side of the one-effect steam holes 8, and the two groups of one-effect dilute solution inlets 11 are respectively arranged at two sides of the heat source inlet 14 and the heat source outlet 15.

The surface A of the base plate 5 is also provided with a double-effect condensate collecting gasket 25, a high-low pressure partition gasket 26, a heat source inlet and outlet partition gasket 27, a cold source inlet and outlet partition gasket 28, a double-effect dilute solution inlet split gasket 29 and a single-effect dilute solution inlet split gasket 30, the middle part of the double-effect condensate collecting gasket 25 is surrounded at the lower side of the double-effect condensate outlet 23, the two side edges of the double-effect condensate collecting gasket 25 extend to the lower side of the inner side of the double-effect steam hole 4, the high-low pressure partition gasket 26 sequentially passes through a group of double-effect dilute solution inlets 7 and a group of single-effect steam holes 8 from one side edge of the base plate 5, a group of double-effect dilute solution inlets 7 and a group of single-effect steam holes 8 and then finally extends to the other side edge of the base plate 5, the heat source inlet and outlet partition gasket 27 is surrounded at the outer sides of the heat source inlet 14 and the heat source outlet 15 and separates the heat source inlet 14 and the, the cold source inlet and outlet separation gasket 28 surrounds the outer sides of the cold source inlet 1 and the cold source outlet 2 and separates the cold source inlet 1 and the cold source outlet 2 from each other, the double-effect dilute solution inlet separation gasket 29 surrounds the outer side of the double-effect dilute solution inlet 7, and the first-effect dilute solution inlet separation gasket 30 surrounds the outer side of the first-effect dilute solution inlet 11.

The surface B of the base plate 5 is also provided with a cold source partition gasket 3, a double-effect dilute solution inlet partition gasket 6, a single-effect dilute solution inlet partition gasket 10, a single-effect concentrated solution outlet gasket 13, a heat source flow passage partition gasket 16, a heat source partition gasket 17, a single-effect condensate collecting gasket 19, a double-effect low-pressure partition gasket 21 and a cold source flow passage partition gasket 24, the cold source partition gasket 3 sequentially passes through the inner sides of a group of double-effect steam holes 4, a cold source outlet 2 and a double-effect condensate outlet 23 from the upper side edge of the base plate 5, the inner sides of the other group of double-effect steam holes 4 and then extends to the upper side edge of the base plate 5, the double-effect dilute solution inlet partition gasket 6 is surrounded on the outer side of the double-effect dilute solution inlet 7, the single-effect dilute solution inlet partition gasket 10 is surrounded on the outer side of the single-effect dilute solution inlet 11, the single-effect concentrated solution outlet gasket 13 is surrounded on the outer side of the single-, heat source subregion gasket 17 sets up between an effect gas-liquid overflow mouth 18 and heat source export 15 and both ends extend to the both sides border of basic slab 5, an effect condensate is collected gasket 19 and is surrounded at an effect condensate export 9 downside and both ends extend to an effect steam hole 8 inboard below respectively, two effect low pressure region isolation gaskets 21 surround in two effect concentrated solution export 20 outsides and two effect low pressure region isolation gaskets 21 both ends tip upwards extend to two effect gas-liquid overflow mouth 22 downside and extend to the both sides border of basic slab 5 to both sides above two effect concentrated solution export 20, cold source runner subregion gasket 24 sets up between cold source import 1 and cold source export 2.

The isolation gasket of the double-effect low-pressure area needs to be high in periphery and low in middle, a certain width is kept in the middle, the double-effect concentrated solution outlet is completely contained at the bottom, the upper double-effect concentrated solution is convenient to collect, and the upper double-effect concentrated solution is discharged out of the system through the double-effect concentrated solution outlet.

The first-effect solution evaporation area is an area below the first-effect gas-liquid overflow outlet 18; the first-effect gas-liquid separation area is an area between the first-effect gas-liquid overflow port 18 and the high-low pressure partition gasket 26; the two-effect solution evaporation area is the area between the high-low pressure partition gasket 26 and the two-effect gas-liquid overflow port 22, and the two-effect gas-liquid separation area is the area between the two-effect gas-liquid overflow port 22 and the two-effect condensate collection gasket 25; the secondary steam condensation heat release area is an area above the secondary condensate collecting gasket 25;

the heat source heat release area is an area below the first-effect gas-liquid overflow outlet 18, the first-effect gas-liquid separation area is an area between the first-effect gas-liquid overflow outlet 18 and the first-effect condensate collection gasket 19, and the first-effect steam condensation heat release area is an area between the first-effect condensate collection gasket 19 and the second-effect low-pressure area separation gasket 21; the two-effect gas-liquid separation zone is a zone between the two-effect low-pressure zone isolation gasket 21 and the cold source partition gasket 3; the cold source heat absorption area is the area inside the cold source partition gasket 3.

Wherein, the five areas between the A-A surfaces and the five areas between the B-B surfaces on the back surface respectively form 5 one-to-one corresponding interface relations: the back of the first-effect solution evaporation area between the A surfaces and the A surfaces is a heat source heat release area between the B surfaces and the B surfaces; the back of the first-effect gas-liquid separation zone between the A surfaces and the A surfaces is the first-effect gas-liquid separation zone between the B surfaces and the B surfaces; the back of the two-effect solution evaporation area between the A surfaces and the A surfaces is a one-effect steam condensation heat release area between the B surfaces and the B surfaces; the back of the double-effect gas-liquid separation zone between the A surface and the A surface is a double-effect gas-liquid separation zone between the B surface and the B surface; the back of the double-effect steam condensation heat release area between the A surfaces and the A surfaces is a cold source heat absorption area between the B surfaces and the B surfaces.

In order to reduce the steam flow resistance and simultaneously reduce the base material of the plate, according to the difficulty degree of the plate processing, one or more round, square or special-shaped openings are adopted for the cold source inlet 1, the cold source outlet 2, the double-effect steam hole 4, the double-effect dilute solution inlet 7, the first-effect steam hole 8, the first-effect condensate outlet 9, the first-effect dilute solution inlet 11, the first-effect concentrated solution outlet 12, the heat source inlet 14, the heat source outlet 15, the first-effect gas-liquid overflow outlet 18, the double-effect concentrated solution outlet 20, the double-effect gas-liquid overflow outlet 22 and the double-effect condensate outlet 23.

One or more gaps or holes are arranged on the first-effect dilute solution inlet shunting gasket 30 and the second-effect dilute solution inlet shunting gasket 29, so that part of dilute solution can enter the first-effect and second-effect solution evaporation areas to realize evaporation, and the first-effect dilute solution inlet shunting gasket and the second-effect dilute solution inlet shunting gasket can be completely cancelled, so that the dilute solution respectively and completely enters the first-effect and second-effect solution evaporation areas to realize different evaporation speeds. Diversion trenches are arranged at the first-effect dilute solution inlet 30 and the second-effect dilute solution inlet 29 so as to improve the convection heat exchange performance.

Before starting the operation, the temperature of the steam evaporated from the first-effect solution evaporation area can be higher than the evaporation temperature of the solution in the second-effect solution evaporation area to ensure that the pressure of the second-effect solution evaporation area is lower than the pressure of the first-effect solution evaporation area, and the steam can also be used as a heat source for evaporating the second-effect solution. In order to establish the heat transfer temperature difference of each subarea and realize the double-effect evaporation and concentration of the dilute solution, the double-effect condensate outlet 23, the first-effect condensate outlet 9 and the communicated space thereof need to be vacuumized, and the vacuum degree of the double-effect condensate outlet 23 is higher than that of the first-effect condensate outlet 9.

The dilute solution to be evaporated and concentrated is used as a cold source, firstly enters the cold source inlet 1 to absorb heat and then is discharged from the cold source outlet 2, and the discharged dilute solution enters the first-effect dilute solution inlet 11 and the second-effect dilute solution inlet 7. The device can adopt the dilute solution to be concentrated as a cold source, not only can be used for preheating the dilute solution to be concentrated, but also can reduce the heat exchange load of the first-effect evaporation zone and the second-effect evaporation zone, and is more energy-saving. According to the practical situation, the cold source inlet and the cold source outlet can be exchanged, and the cold source can be in and out from the top and can also be in and out from the bottom.

The working medium of the first-effect concentrated solution outlet 13 is used as the working medium of the second-effect dilute solution inlet 7, and can be used for increasing the outlet concentration of the solution to be concentrated.

Because the plate heat exchanger has compact structure, the plate heat exchanger is particularly suitable for heat transfer of working media with higher heat exchange coefficients in liquid or phase change processes and the like, the conventional easily-obtained cold source is natural water with ambient temperature or dilute solution with ambient temperature, and the heat source can adopt steam, high-temperature liquid or gaseous working media and requires the heat source temperature to be higher than 60 ℃ in consideration of the heat transfer temperature difference in the two-effect evaporator and the pressure resistance of the plates. According to the actual situation, the heat source inlet and the heat source outlet can be interchanged, and the heat source can be moved up and down or moved down and up and down.

A method of using a two-effect evaporator, comprising the steps of:

the method comprises the following steps: the external dilute solution enters a one-effect solution evaporation area between the A-A surfaces, partial evaporation is carried out after the external dilute solution absorbs the heat energy released by a heat source heat release area between the B-B surfaces on the back surfaces of the external dilute solution, and the non-evaporated concentrated solution enters a one-effect concentrated solution outlet 12 through the one-effect solution evaporation area and a one-effect gas-liquid overflow outlet between the A-A surfaces respectively;

step two: the evaporated steam respectively enters a first-effect gas-liquid separation area between the A surface and a first-effect gas-liquid separation area between the B surface and the B surface through a first-effect gas-liquid overflow outlet 18, then enters a first-effect steam condensation heat release area between the B surface and the B surface through a first-effect steam hole 8, releases latent heat to the low-pressure solution in a second-effect solution evaporation area between the A surface and the A surface, is condensed into condensate, and is discharged out of the system from a first-effect condensate outlet 9;

step three: the low-pressure solution in the double-effect solution evaporation area between the A surfaces and the A surfaces absorbs heat and then is partially evaporated, and the non-evaporated concentrated solution enters the double-effect concentrated solution outlet 20 through the double-effect solution evaporation area between the A surfaces and the double-effect gas-liquid overflow outlet respectively;

step four: the evaporated double-effect steam enters the double-effect gas-liquid separation area between the A surface and the double-effect gas-liquid separation area between the B surface and the B surface through the double-effect gas-liquid overflow outlet respectively, then enters the double-effect steam condensation heat release area between the A surface and the A surface through the double-effect steam hole 4, releases latent heat to the cold source between the B surface and the B surface, is condensed into condensate, and is discharged out of the system from the double-effect condensate outlet 23.

The invention mainly realizes the temperature gradient evaporation and condensation of dilute solution by adding a plurality of through holes on the heat exchange plate and arranging a plurality of gaskets on the front surface and the back surface of the heat exchange plate to divide the area of the heat exchange plate into detail partitions, and dividing an odd-even channel into two low-pressure evaporation areas, two condensation areas, a high-pressure cold source cooling area and a high-pressure heat source heat release area. The double-effect evaporator has high heat exchange coefficient and compact structure. Moreover, the system is convenient to disassemble, assemble and maintain, and the evaporation and condensation amount of the dilute solution can be adjusted by changing the number of the heat exchange plates. The invention can be additionally provided with three or more than three low-pressure evaporation areas and condensation areas to form a multi-effect evaporator with three or more than three effects.

The above description of the present invention is intended to be illustrative. Various modifications, additions and substitutions for the specific embodiments described may be made by those skilled in the art without departing from the scope of the invention as defined in the accompanying claims.