CN103807946B - The rectification regenerating unit of heat source tower anti-freezing solution - Google Patents

Abstract

The invention discloses the rectification regenerating unit of a kind of heat source tower anti-freezing solution, including working subsystem and regeneration subsystem; Described working subsystem includes heat source tower heat pump system and second and regulates the closed circuit that valve (9) is constituted; Described regeneration subsystem includes anti-icing fluid blood circulation and draws fluid circulation; Described anti-icing fluid blood circulation and drawing is intercoupled by positive permeability apparatus (8) between fluid circulation.

Description

Rectification and regeneration device for heat source tower antifreeze solution

technical field

The invention relates to the field of air conditioning and refrigeration, in particular to a device for rectifying and regenerating antifreeze solution of a heat source tower.

Background technique

In order to deal with the frosting problem of air source heat pumps in winter, there are currently two types of solutions. One is to take various defrosting measures against the frosting problem; the other is to use the heat source tower heat pump system that has gradually received attention in recent years. To replace the air source heat pump system, while avoiding the problem of frosting, it also retains the characteristics of the heat pump system, which can be used in both winter and summer and has high efficiency. The heat source tower heat pump system exchanges heat and mass with the air through the antifreeze solution, absorbs the sensible heat and latent heat in the air to provide heat source for the evaporator, so that the system can still operate efficiently and stably under the working condition below 0°C. The heat source tower heat pump system has great application potential in the energy-saving market. At present, there are very few applications and researches on the heat source tower heat pump system at home and abroad. From the perspective of operation, one of the main problems to be solved is how to prevent freezing after moisture absorption. The solution can be regenerated, and the regeneration methods that can be used are divided into two categories, namely thermal regeneration and work-driven regeneration. Thermal regeneration includes non-boiling regeneration and boiling regeneration. The former has the advantages of low-grade energy utilization, but has the disadvantages of large mass transfer potential difference, low thermal efficiency and complicated operation, and there are certain difficulties in the actual promotion process (for example, the application number is 201010567051.4 and 200910098008.5); the latter boils and evaporates the water in the solution to separate in a vacuum environment, has good heat and mass transfer performance, lower requirements for the temperature level of low-grade heat sources, and has great energy-saving potential. The system is simple, but The antifreeze solution contains more non-condensable gas in the open cycle, which greatly affects the vacuum boiling effect, so the vacuum pump needs to be continuously evacuated to maintain a certain vacuum degree, thereby generating a large demand for electric energy, making the boiling regeneration system The efficiency is greatly reduced and the feasibility is lost. Work-driven regeneration uses a reverse osmosis device to change the chemical potential of water in a concentrated solution by applying external pressure and make it permeate into a dilute solution to achieve water separation. The patent application number 200910307940.4 first proposed a single-stage regeneration system, but did not Effectively solve the problem of antifreeze heating, the operating pressure is high, and the pressure energy recovery is not considered. The patent application number 201320019403.1 adopts two-stage osmosis to reduce the operating pressure, and introduces pressure energy recovery and heat pump unit recooler to optimize the system structure, further The efficiency of the system is improved, but the addition of the energy recovery device increases the initial investment of the system and reduces the technical economy.

In summary, among many technical measures for antifreeze regeneration in heat source towers, boiling regeneration is a relatively simple and efficient regeneration method. It can effectively use low-grade heat sources without increasing high pressure or energy recovery. However, boiling regeneration usually uses water as a low boiling point component and separates it from the solution by endothermic evaporation, which brings about two problems: one is that the low concentration of the antifreeze solution makes the required heat source temperature smaller and the temperature difference The proportion of heat transfer loss is relatively large; the second is that the latent heat of vaporization of water is relatively large, and more heat needs to be consumed during the separation process. In view of the above problems, one solution is to carry out multi-effect regeneration, but this will cause the complexity of the system and reduce the technical and economic performance. Therefore, it is necessary to invent an antifreeze solution regeneration that can solve the above problems and maintain the simplicity of single-effect regeneration device.

Contents of the invention

The technical problem to be solved by the present invention is to provide a rectification and regeneration device for heat source tower antifreeze solution with simple structure.

In order to solve the above-mentioned technical problems, the present invention provides a rectification regeneration device for antifreeze solution in a heat source tower, including a working subsystem and a regeneration subsystem; the working subsystem includes a circulation loop formed by a heat source tower heat pump system and a second regulating valve; The regeneration subsystem includes an antifreeze circulation system and a drawing liquid circulation system; the antifreeze circulation system and the drawing liquid circulation system are coupled to each other through a forward osmosis device.

As the improvement of the rectification regeneration device of the heat source tower antifreeze solution according to the present invention: the antifreeze circulation system includes a first regulating valve, an antifreeze booster pump, a filter, a first solution heat exchanger, a second solution exchanger Heater and heater; the solution outlet of the heat source tower heat pump system, the first regulating valve, the antifreeze booster pump, the filter, the low-temperature liquid pipeline of the first solution heat exchanger, and the low-temperature liquid of the second solution heat exchanger The heating pipes of the pipeline and the heater are connected to each other in turn; the heating pipeline of the heater is also connected to the antifreeze inlet of the forward osmosis device; the antifreeze outlet of the forward osmosis device passes through the high-temperature liquid pipeline of the first solution heat exchanger It is connected with the circulation loop formed by the heat source tower heat pump system and the second control valve; the draw liquid circulation system includes a third control valve, a third solution heat exchanger, a rectifier, a condenser, a booster pump at the top of the tower, a draw A solution booster pump and a condensate pump; the draw liquid outlet of the forward osmosis device is connected to the draw liquid inlet of the rectifier after passing through the third regulating valve and the low-temperature liquid pipeline of the third solution heat exchanger; the rectifier The steam outlet at the top of the tower passes through the condensing pipe of the condenser, the booster pump at the top of the tower and the booster pump for drawing solution in turn, and then connects with the drawing liquid inlet of the forward osmosis device; the outlet at the bottom of the rectifier is connected with the condensate pump, the first The high-temperature liquid pipeline of the three-solution heat exchanger is connected with the high-temperature liquid pipeline of the second solution heat exchanger; the draw solution outlet of the forward osmosis device is connected with the draw solution inlet of the forward osmosis device on the other hand through the draw solution booster pump connected.

As a further improvement of the rectification regeneration device of the heat source tower antifreeze solution according to the present invention: when the heat source tower heat pump system is open, one end of the cooling pipe of the condenser is formed with the heat source tower heat pump system and the second regulating valve. The other end of the cooling pipe of the condenser is connected with the solution outlet of the heat source tower heat pump system through the fourth regulating valve; one end of the cooling pipe at the top of the rectifier is connected with the heat source tower heat pump system and the second regulator The circulation loop formed by the valves is connected; the other end of the tower top cooling pipeline in the rectifier is connected with the solution outlet of the heat source tower heat pump system through the fourth regulating valve.

As a further improvement of the rectification regeneration device of the heat source tower antifreeze solution according to the present invention: when the heat source tower heat pump system is closed, one end of the condenser cooling pipe passes through the fourth regulating valve and the circulating solution of the heat source tower heat pump system The outlet is connected; the other end of the cooling pipe of the condenser is connected with the circulating solution inlet of the heat source tower heat pump system; one end of the tower cooling pipe in the rectifier is circulated with the heat source tower heat pump system through the fourth regulating valve The solution outlet is connected; the other end of the tower top cooling pipe in the rectifier is connected with the circulation solution inlet of the heat source tower heat pump system.

As a further improvement of the rectification regeneration device of the heat source tower antifreeze solution according to the present invention: the antifreeze solution used in the working subsystem and the antifreeze circulation system is an aqueous solution of organic matter or aqueous solution of inorganic matter; the aqueous solution of organic matter or aqueous solution of inorganic matter The water in the water is a low boiling point component; the drawing solution used in the drawing liquid circulation system is an organic aqueous solution that is completely miscible with water; the water in the organic aqueous solution that is completely miscible with water is a high boiling point component.

As a further improvement of the rectification regeneration device of the heat source tower antifreeze solution according to the present invention: the antifreeze inlet and the antifreeze outlet in the forward osmosis device, as well as the draw liquid inlet and the draw liquid outlet, are separated by a semi-permeable membrane; The semi-permeable membrane selectively passes water and has a high retention of antifreeze solution and the remaining components in the draw solution.

As a further improvement of the heat source tower antifreeze solution rectification regeneration device of the present invention: the heat source tower heat pump system is mainly composed of a heat source tower and a heat pump system.

As a further improvement of the heat source tower antifreeze solution rectification regeneration device of the present invention: the reboiler heating pipe at the bottom of the rectifier communicates with an external heat source.

Compared with the existing heat source tower antifreeze solution boiling regeneration system, the present invention has the following advantages:

1) When the temperature of the low-grade heat source is high (40°C-55°C), only single-effect regeneration can be used to maintain efficient utilization of the heat source, which simplifies the regeneration structure. The present invention adopts forward osmosis technology, and its main feature is that the water in the drawn solution is a high-boiling component, and the drawn solution is used to absorb the water in the antifreeze solution during work, and then the drawn solution is regenerated. Excess water is distilled from the bottom of the rectification tower, and the reboiler at the bottom of the rectification tower is suitable for a heat source at 40°C to 55°C, so it avoids the multi-effect regeneration process used in the usual boiling regeneration system to make full use of the heat source, and simplifies the process. Recycled structure, enhanced techno-economic performance.

2) Separation of unit water requires less heat, that is, it has higher thermal efficiency. Since the water in the used drawing solution is composed of high boiling point components, the heat consumed in the separation process is mainly used for the endothermic evaporation of the low boiling point components in the drawing solution, but the content of the low boiling point components in the antifreeze solution is relatively low, so Less latent heat of evaporation is consumed, which improves the thermal efficiency of the system.

3) The circulation rate of the antifreeze solution is low during regeneration. The present invention adopts rectification regeneration. What flows out from the bottom of the rectification tower is high-purity water, and what flows out from the top of the tower is high-purity gaseous matter. The circulation ratio required for separating unit water is mainly related to the concentration of the drawn solution, and its value is generally 2 times, so it is more conducive to system miniaturization.

Description of drawings

The specific implementation manners of the present invention will be described in further detail below in conjunction with the accompanying drawings.

Fig. 1 is a kind of structural representation of the present invention (open type antifreeze circulation system 1a);

Fig. 2 is another schematic diagram of the structure of the present invention (closed antifreeze circulation system 1a).

detailed description

Figures 1 to 2 show a rectification regeneration device for the antifreeze solution of the heat source tower.

It includes a working subsystem and a regeneration subsystem; the working subsystem includes a circulation loop formed by a heat source tower heat pump system and a second regulating valve 9 . The regeneration subsystem includes an antifreeze circulation system and a draw liquid circulation system; the antifreeze circulation system and the draw liquid circulation system are coupled to each other through a forward osmosis device 8 . The antifreeze solution is used in the working subsystem. During the circulation process, after continuously absorbing the water vapor in the air, the concentration is continuously reduced; and once the concentration is too low, the antifreeze circulation system and the draw liquid circulation system are started. After the antifreeze solution is used in conjunction with the antifreeze circulation system and the draw solution circulation system, the concentration of the antifreeze solution is restored.

The antifreeze solution used in the working subsystem and the antifreeze circulation system is organic or inorganic aqueous solution; the water in the organic or inorganic aqueous solution is a low boiling point component; the drawing solution used in the drawing liquid circulation system is selected to be completely miscible with water The organic aqueous solution; the water in the organic aqueous solution that is completely miscible with water is a high boiling point component.

Antifreeze solution can choose organic aqueous solution (such as ethylene glycol solution) or inorganic aqueous solution (such as calcium chloride solution), in which water is the low boiling point component. The drawing solution is an aqueous solution of organic matter that is completely miscible with water (such as acetone-water solution), in which water is a high boiling point component. In the forward osmosis device 8, the antifreeze inlet and the antifreeze outlet, as well as the draw solution inlet and the draw solution outlet, are separated by a semi-permeable membrane; the semi-permeable membrane selectively passes through moisture, and has an effect on the antifreeze solution and the remaining components in the draw solution High retention. The heat source tower heat pump system is mainly composed of two parts: the heat source tower and the heat pump system. The top of the rectifier has built-in reflux cooling pipes, and the bottom of the tower has built-in reboiler heating pipes. The heat source of the heater 7 and the rectifier 12 should adopt a low-grade heat source within the range of 40°C to 55°C, such as solar energy, waste heat source or heat pump system's own heat supply source.

Embodiment 1. The following descriptions are the specific structural features of the open antifreeze circulation system 1a.

The working subsystem includes an open antifreeze circulation system 1 a and a circulation loop formed by a second regulating valve 9 .

The antifreeze circulation system includes a first regulating valve 2, an antifreeze booster pump 3, a filter 4, a first solution heat exchanger 5, a second solution heat exchanger 6, and a heater 7; the open antifreeze circulation system 1a The solution outlet is connected to the antifreeze booster pump 3 through the first regulating valve 2, and the antifreeze booster pump 3 is connected to one end of the low-temperature liquid pipeline of the first solution heat exchanger 5 through the filter 4, and the first solution heat exchanger The other end of the low-temperature liquid pipeline of 5 is connected with one end of the low-temperature liquid pipeline of the second solution heat exchanger 6, and the other end of the low-temperature liquid pipeline of the second solution heat exchanger 6 is connected with one end of the heater 7 heating pipeline, heating The other end of the heating pipe of the device 7 is connected to each other with the antifreeze inlet of the forward osmosis device 8; the antifreeze outlet of the forward osmosis device 8 is connected with one end of the high temperature liquid pipeline of the first solution heat exchanger 5, and the The other end of the high-temperature liquid pipeline communicates with the circulation loop formed by the heat pump system of the heat source tower and the second regulating valve 9 .

The draw liquid circulation system includes a third regulating valve 10, a third solution heat exchanger 11, a rectifier 12, a condenser 13, a tower top booster pump 14, a draw solution booster pump 15, and a condensed water pump 16; a forward osmosis device 8 The outlet of the drawn liquid is divided into two paths: one path passes through the third regulating valve 10 and the low-temperature liquid pipeline of the third solution heat exchanger 11 and is connected to the inlet of the extracted liquid of the rectifier 12; the other path is connected to the top booster pump 14 connected to the exit. The tower top steam outlet of rectifier 12 is connected with the drawing solution outlet of forward osmosis device 8 after passing through the condensing pipeline of condenser 13 and tower top booster pump 14 successively (as mentioned above, another way is connected with tower top booster pump 14 connected to the outlet); the water outlet at the bottom of the rectifier 12 passes through the condensed water pump 16, the high-temperature liquid pipeline of the third solution heat exchanger 11 and the high-temperature liquid pipeline of the second solution heat exchanger 6, and then sets the water outlet, and passes through the outlet The water port discharges the effluent of rectifier 12. The outlet of the top booster pump 14 is connected to the draw solution inlet of the forward osmosis device 8 through the draw solution booster pump 15 .

One end of the cooling pipeline of the condenser 13 is connected with the circulation loop formed by the heat source tower heat pump system and the second regulating valve 9; the other end of the cooling pipeline of the condenser 13 is connected with the solution outlet of the open antifreeze circulation system 1a through the fourth regulating valve 17 One end of the tower top cooling pipe in the rectifier 12 is connected with the circulation loop formed by the open antifreeze circulation system 1a and the second regulating valve 9; the other end of the tower top cooling pipe in the rectifier 12 passes through the first The four regulating valves 17 are connected with the solution outlet of the open antifreeze circulation system 1a.

When using it specifically, the steps are as follows:

1. When the concentration of the antifreeze solution flowing out of the antifreeze solution outlet of the open antifreeze circulation system 1a is between the set upper limit and the lower limit, the system is in the working mode, the second regulating valve 9 is opened, the first regulating valve 2 and the fourth regulating valve Valve 17 is fully closed, that is, the working subsystem is running and the regenerative subsystem is closed. At this time, the antifreeze solution flows out from the antifreeze solution outlet and then flows back to the antifreeze solution inlet of the open antifreeze circulation system 1a through the second regulating valve 9 to exchange heat and mass with the air. After repeated cycles, the concentration of the antifreeze solution flowing out of the antifreeze solution outlet will continue to become thinner.

2. When the concentration of the antifreeze solution flowing out of the antifreeze solution outlet of the open antifreeze circulation system 1a is lower than the set lower limit, the system is in the working regeneration mode, and the first regulating valve 2 and the fourth regulating valve 17 are opened, that is, the working subsystem and The regenerative subsystems are both turned on simultaneously.

2.1 At this time, the antifreeze solution flowing out from the antifreeze solution outlet of the open antifreeze circulation system 1a is divided into three paths:

2.1.1 The first road:

is bypassed directly through the second regulating valve 9;

2.1.2 The second way:

Through the first regulating valve 2, it is pressurized by the antifreeze solution booster pump 3, and then filtered by the filter 4 to reach the inlet water quality required by the forward osmosis device 8, and then enters the low-temperature liquid pipeline of the first solution heat exchanger 5 to absorb high-temperature liquid After the heat released by the antifreeze solution in the pipeline, the temperature rises, and then enters the low-temperature liquid pipeline of the second solution heat exchanger 6, and after absorbing the heat released by the water in the high-temperature liquid pipeline, the temperature rises further, and then enters the heater 7 After absorbing the heat provided by an external low-grade heat source, the temperature further rises above 0°C (such as 5°C), and then flows into the forward osmosis device 8 through the antifreeze solution inlet. Under the action of the osmotic pressure of the solution, the antifreeze solution The moisture in the water enters the drawing solution on the other side through the semi-permeable membrane, and the concentration of the antifreeze solution increases, and then flows out from the outlet of the antifreeze solution, and enters the open antifreeze circulation system 1a after passing through the high-temperature liquid pipeline of the first solution heat exchanger 5 In the circulation loop formed by the second regulating valve 9, it is mixed with the antifreeze solution in the circulation loop;

2.1.3 The third way:

Divided into two paths again through the fourth regulating valve 17:

After the first path enters the top cooling pipe of the rectifier 12 (after condensing a part of the top vapor into liquid reflux, the temperature rises; step 2.5), it is formed with the open antifreeze circulation system 1a and the second regulating valve 9 Antifreeze solution mixing in the circulation loop;

After the second road enters the cooling pipe of the condenser 13 (after absorbing the latent heat of condensation released by the low-boiling steam in the condensation pipe, the temperature rises, then mixes with the antifreeze solution flowing out from the tower top cooling pipe of the rectifier 12, and finally Then mix with the antifreeze solution in the circulation circuit formed by the open antifreeze circulation system 1a and the second regulating valve 9, as in step 2.6); in the circulation circuit formed by the open antifreeze circulation system 1a and the second regulating valve 9 Antifreeze solution flow mixing;

2.2 The antifreeze solution in the circulation loop formed by the open antifreeze circulation system 1a and the second regulating valve 9 flows into the open antifreeze circulation system 1a to exchange heat and mass with the air.

2.3 The concentrated drawing solution enters the forward osmosis device 8 from the drawing solution inlet of the forward osmosis device 8, absorbs the moisture in the antifreeze solution under the action of the osmotic pressure of the solution, and the concentration becomes smaller, becomes a dilute drawing solution, and then flows out from the drawing solution outlet.

2.4 The dilute draw solution flowing out from the draw solution outlet of the forward osmosis device 8 is divided into two paths:

The first way:

The pressure is reduced to the working pressure of the rectifier 12 through the third regulating valve 10, and then enters the low-temperature liquid pipeline of the third solution heat exchanger 11 (absorbs the heat released by the high-purity water in the high-temperature liquid pipeline, and the temperature rises to saturation liquid temperature; after step 2.8), enter the rectifier 12 from the drawing solution inlet;

Second way:

Mixed with the high-purity low-boiling point liquid flowing out from the booster pump 14 at the top of the tower, the concentration increases and becomes a concentrated draw solution again.

2.5. After the dilute drawing solution enters the rectifier 12, high-purity water is collected at the bottom of the tower through heat and mass exchange, and high-purity low-boiling steam is collected at the top of the tower.

A part of the low-boiling steam at the top of the tower releases heat to the antifreeze solution in the cold pipe built in the top of the tower, and becomes the top reflux liquid.

The external heat source enters the reboiler heating pipe at the bottom of the rectifier 12 to heat a part of the high-purity water at the bottom of the tower to reflux steam at the bottom of the tower.

Finally, high-purity low-boiling point steam flows out from the steam outlet at the top of the tower, and high-purity water flows out from the water outlet at the bottom of the tower.

2.6 The high-purity low-boiling point steam flowing out from the steam outlet of the rectifier 12 flows into the condensation pipe of the condenser 13, and after releasing heat to the antifreeze solution in the cooling pipe, the temperature decreases and the phase changes into a high-purity low-boiling point liquid, and then passes through Tower top booster pump 14 is pressurized to normal pressure (the second road antifreeze solution in step 2.1.3);

2.7 The concentrated draw solution passed through the tower top booster pump 14 is pressurized by the draw solution booster pump 15 and then enters the forward osmosis device 8 from the draw solution inlet, and circulates to step 2.3.

2.8 The high-purity water flowing out of the water outlet of the rectifier 12 is pressurized to normal pressure by the condensate pump 16 and then passes through the high-temperature liquid pipeline of the third solution heat exchanger 11 and the high-temperature liquid pipeline of the second solution heat exchanger 6 in sequence discharge;

At this time, through the high-temperature liquid pipeline of the third solution heat exchanger 11 and the high-temperature liquid pipeline of the second solution heat exchanger 6, heat is released to the antifreeze solution in the corresponding low-temperature liquid pipeline (the first path of step 2.4).

2.9 In the working regeneration mode, the amount of water discharged from the regeneration subsystem is greater than the amount of water absorbed from the air by the open antifreeze circulation system 1a. After repeated cycles, the concentration of the solution will continue to become thicker.

3. When the concentration of the antifreeze solution flowing out of the antifreeze solution outlet of the open antifreeze circulation system 1a is higher than the set upper limit, the system returns to the working mode, the working subsystem runs, and the regeneration subsystem closes.

Embodiment 2. The following are the specific structural features of the closed antifreeze circulation system 1b.

The working subsystem includes a closed antifreeze circulation system 1b and a circulation loop formed by a second regulating valve 9 .

The antifreeze circulation system includes a first regulating valve 2, an antifreeze booster pump 3, a filter 4, a first solution heat exchanger 5, a second solution heat exchanger 6, and a heater 7; the closed antifreeze circulation system 1b The solution outlet is connected to the antifreeze booster pump 3 through the first regulating valve 2, and the antifreeze booster pump 3 is connected to one end of the low-temperature liquid pipeline of the first solution heat exchanger 5 through the filter 4, and the first solution heat exchanger The other end of the low-temperature liquid pipeline of 5 is connected with one end of the low-temperature liquid pipeline of the second solution heat exchanger 6, and the other end of the low-temperature liquid pipeline of the second solution heat exchanger 6 is connected with one end of the heater 7 heating pipeline, heating The other end of the heating pipe of the device 7 is connected to each other with the antifreeze inlet of the forward osmosis device 8; the antifreeze outlet of the forward osmosis device 8 is connected with one end of the high temperature liquid pipeline of the first solution heat exchanger 5, and the The other end of the high-temperature liquid pipeline communicates with the circulation loop formed by the heat pump system of the heat source tower and the second regulating valve 9 .

The draw liquid circulation system includes a third regulating valve 10, a third solution heat exchanger 11, a rectifier 12, a condenser 13, a tower top booster pump 14, a draw solution booster pump 15, and a condensed water pump 16; a forward osmosis device 8 The outlet of the drawn liquid is divided into two paths: one path passes through the third regulating valve 10 and the low-temperature liquid pipeline of the third solution heat exchanger 11 and is connected to the inlet of the extracted liquid of the rectifier 12; the other path is connected to the top booster pump 14 connected to the exit. The tower top steam outlet of rectifier 12 is connected successively through the condensing pipeline of condenser 13, tower top booster pump 14 and the drawing solution outlet of forward osmosis device 8; A water outlet is provided behind the high-temperature liquid pipeline of the third solution heat exchanger 11 and the high-temperature liquid pipeline of the second solution heat exchanger 6, through which the outlet water of the rectifier 12 is discharged. The outlet of the top booster pump 14 is connected to the draw solution inlet of the forward osmosis device 8 through the draw solution booster pump 15 .

One end of the cooling pipe of the condenser 13 is connected with the circulating solution outlet of the heat source tower heat pump system through the fourth regulating valve 17; the other end of the cooling pipe of the condenser 13 is connected with the circulating solution inlet of the heat source tower heat pump system; One end of the cooling pipe at the top of the tower is connected with the circulating solution outlet of the heat source tower heat pump system through the fourth regulating valve 17; the other end of the cooling pipe at the top of the rectifier 12 is connected with the circulating solution inlet of the heat source tower heat pump system.

When using it specifically, the steps are as follows:

1. When the concentration of the antifreeze solution flowing out of the antifreeze solution outlet of the closed antifreeze circulation system 1b is between the set upper limit and the lower limit, the system is in the working mode, the second regulating valve 9 is opened, the first regulating valve 2 and the fourth regulating valve Valve 17 is fully closed, that is, the working subsystem is running and the regenerative subsystem is closed. At this time, the antifreeze solution flows out from the antifreeze solution outlet and then flows back to the antifreeze solution inlet of the closed antifreeze circulation system 1b through the second regulating valve 9 to exchange heat and mass with the air. After repeated cycles, the concentration of the antifreeze solution flowing out of the antifreeze solution outlet will continue to become thinner.

2. When the concentration of the antifreeze solution flowing out of the antifreeze solution outlet of the closed antifreeze circulation system 1b is lower than the set lower limit, the system is in the working regeneration mode, and the first regulating valve 2 and the fourth regulating valve 17 are opened, that is, the working subsystem and The regenerative subsystems are both turned on simultaneously.

2.1 At this time, the antifreeze solution flowing out from the antifreeze solution outlet of the closed antifreeze circulation system 1b is divided into two paths:

2.1.1 The first road:

is bypassed directly through the second regulating valve 9;

2.1.2 The second way:

Through the first regulating valve 2, it is pressurized by the antifreeze solution booster pump 3, and then filtered by the filter 4 to reach the inlet water quality required by the forward osmosis device 8, and then enters the low-temperature liquid pipeline of the first solution heat exchanger 5 to absorb high-temperature liquid After the heat released by the antifreeze solution in the pipeline, the temperature rises, and then enters the low-temperature liquid pipeline of the second solution heat exchanger 6 (whether it should be a low-temperature liquid pipeline), and after absorbing the heat released by the water in the high-temperature liquid pipeline, the temperature further increases. After rising, it enters the heating pipe of the heater 7, and after absorbing the heat provided by the external low-grade heat source, the temperature further rises to above 0°C (such as 5°C), and then flows into the forward osmosis device 8 through the antifreeze solution inlet, and infiltrates in the solution Under the action of pressure, the water in the antifreeze solution enters the drawing solution on the other side through the semipermeable membrane, the concentration of the antifreeze solution becomes larger, and then flows out from the outlet of the antifreeze solution, and after passing through the high-temperature liquid pipeline of the first solution heat exchanger 5, Enter the circulation loop formed by the closed antifreeze circulation system 1b and the second regulating valve 9, and mix with the antifreeze solution in the circulation loop;

2.2 The antifreeze solution in the circulation loop formed by the closed antifreeze circulation system 1b and the second regulating valve 9 flows into the closed antifreeze circulation system 1b to exchange heat and mass with the air.

2.3 The concentrated drawing solution enters the forward osmosis device 8 from the drawing solution inlet of the forward osmosis device 8, absorbs the moisture in the antifreeze solution under the action of the osmotic pressure of the solution, and the concentration becomes smaller, becomes a dilute drawing solution, and then flows out from the drawing solution outlet.

2.4 The dilute draw solution flowing out from the draw solution outlet of the forward osmosis device 8 is divided into two paths:

The first way:

The pressure is reduced to the working pressure of the rectifier 12 through the third regulating valve 10, and then enters the low-temperature liquid pipeline of the third solution heat exchanger 11 (absorbs the heat released by the high-purity water in the high-temperature liquid pipeline, and the temperature rises to saturation liquid temperature; after step 2.8), enter the rectifier 12 from the drawing solution inlet;

Second way:

Mixed with the high-purity low-boiling point liquid flowing out from the booster pump 14 at the top of the tower, the concentration increases and becomes a concentrated draw solution again.

2.5. After the dilute drawing solution enters the rectifier 12, high-purity water is collected at the bottom of the tower through heat and mass exchange, and high-purity low-boiling steam is collected at the top of the tower.

A part of the low-boiling steam at the top of the tower releases heat to the circulating solution (the first circulating solution in step 2.1.3) in the cold pipe built in the top of the tower, and becomes the top reflux liquid.

The external heat source enters the reboiler heating pipe at the bottom of the rectifier 12 to heat a part of the high-purity water at the bottom of the tower to reflux steam at the bottom of the tower.

Finally, high-purity low-boiling point steam flows out from the steam outlet at the top of the tower, and high-purity water flows out from the water outlet at the bottom of the tower.

2.6 The high-purity low-boiling point steam flowing out from the steam outlet of the rectifier 12 flows into the condensation pipe of the condenser 13, and after releasing heat to the circulating solution in the cooling pipe, the temperature decreases and the phase changes into a high-purity low-boiling point liquid, and then passes through The booster pump 14 at the top of the tower is pressurized to normal pressure (the second road circulating solution in step 2.9);

2.7 The concentrated draw solution passed through the tower top booster pump 14 is pressurized by the draw solution booster pump 15 and then enters the forward osmosis device 8 from the draw solution inlet, and circulates to step 2.3.

2.8 The high-purity water flowing out of the water outlet of the rectifier 12 is pressurized to normal pressure by the condensate pump 16 and then passes through the high-temperature liquid pipeline of the third solution heat exchanger 11 and the high-temperature liquid pipeline of the second solution heat exchanger 6 in sequence discharge;

At this time, heat is released to the antifreeze solution in the corresponding low-temperature liquid pipeline through the high-temperature liquid pipeline of the third solution heat exchanger 11 and the high-temperature liquid pipeline of the second solution heat exchanger 6 (the first path of step 2.4).

2.9 The circulating solution flowing out from the circulating solution outlet of the closed heat source tower heat pump 1b passes through the fourth regulating valve 17 and is divided into two paths:

After the first path enters the tower top cooling pipe of the rectifier 12 (after condensing a part of the tower top steam into a liquid reflux, the temperature rises; step 2.5), and then returns to the circulating solution inlet of the closed heat source tower heat pump 1b;

After the second road enters the cooling pipe of the condenser 13 (after absorbing the latent heat of condensation released by the low-boiling steam in the condensation pipe, the temperature rises, and then mixes with the circulating solution flowing out from the tower top cooling pipe of the rectifier 12, as Step 2.6); finally return to the circulation solution inlet of the closed antifreeze circulation system 1b;

2.10 In the working regeneration mode, the amount of water discharged from the regeneration subsystem is greater than the amount of water absorbed from the air by the closed antifreeze circulation system 1b. After repeated cycles, the concentration of the solution will continue to become thicker.

3. When the concentration of the antifreeze solution flowing out of the antifreeze solution outlet of the closed antifreeze circulation system 1b is higher than the set upper limit, the system returns to the working mode, the working subsystem runs, and the regeneration subsystem closes.

The calculation parameters of implementation example 1 are shown in Table 1 (for 1kg of water vapor absorbed from the air by the heat source tower heat pump system), the system is in the working regeneration mode, and the design conditions are: ambient temperature 5°C, forward osmosis temperature 5°C, antifreeze solution using Calcium chloride solution, the drawing solution is acetone-water solution, the freezing point of the antifreeze solution is -10°C ~ -12.5°C, the latent heat ratio of the heat source tower is 20%, the dehydration rate is 1.5, and the mass concentration range of the antifreeze solution is 18%. ~20%, the inlet/outlet mass concentration of the drawn solution is 49.4%/39.4%, and an osmotic pressure difference of 7Mpa can be generated during forward osmosis. The heat exchange temperature difference of the generator is 5°C, and the condensation temperature is -3°C. The calculated total average circulation rate of the antifreeze solution is 633, the average circulation rate of the antifreeze solution entering the forward osmosis device is 5.06, the circulation rate of the dilute drawing solution is 5.71, and the circulation rate of the dilute drawing solution entering the rectifier is 2.39. The pressure is 7851pa, the heat source temperature required by the rectifier is 46.3°C, the condensation temperature of the rectifier is -3°C, the heat consumption of the rectifier is 615.2kJ/kg, the heat consumption of the heater is 8.7kJ/kg, and the antifreeze solution is pressurized The power consumption of the pump is 3.86kJ/kg, the power consumption of the booster pump for drawing solution is 3.27kJ/kg, the power consumption of the booster pump at the top of the tower is 0.08kJ/kg, the power consumption of the condensate pump is 0.14kJ/kg, and the minimum dehydration theoretical power consumption of the system is 12.6kJ/kg (the minimum work needed to separate 1kg of water from a large amount of 18% antifreeze solution), the actual heat consumption is 80.7kJ/kg, and the consumed electric energy is 7.35kJ/kg, so the total exergy efficiency is 14.3%, and the regenerative heat efficiency is 400% (the regenerative heat efficiency is defined as the ratio of the heat required to evaporate 1 kg of water to the heat required to actually separate 1 kg of water). It can be seen that compared with the conventional boiling regeneration system, the present invention realizes the effect of multi-effect evaporation regeneration by using single-effect rectification regeneration, simplifies the system structure, and the heat required for separating unit mass of water is only equivalent to conventional single-effect boiling 1/4 of the heat required for regeneration, and the circulation rate of the antifreeze solution and the dilute draw solution entering the rectifier is smaller, reducing the heating amount.

It can be seen that, compared with the prior art, the present invention has high regenerative heat efficiency, simple system, better technical and economic value, and effectively realizes the original intention of the present invention.

In the above implementation examples, the design parameters of the system can be reasonably determined by comprehensively considering the specific use conditions and requirements, technical and economic performance and other factors, so as to take into account the applicability and economy of the system.

Table 1. Thermodynamic calculation results of implementation example 1 (for 1kg condenser outlet liquid working fluid R134a)

Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and many variations are possible. All deformations that can be directly derived or associated by those skilled in the art from the content disclosed in the present invention should be considered as the protection scope of the present invention.

Claims (7)

1. The rectification regeneration device of the heat source tower antifreeze solution comprises a work subsystem and a regeneration subsystem; the work subsystem includes a heat source tower heat pump system and a circulation loop formed by a second regulating valve (9); it is characterized in that: the The regeneration subsystem includes antifreeze circulation system and draw liquid circulation system; The antifreeze circulation system and the drawing liquid circulation system are mutually coupled through a forward osmosis device (8); the antifreeze circulation system includes a first regulating valve (2), an antifreeze booster pump (3), a filter ( 4), the first solution heat exchanger (5), the second solution heat exchanger (6) and the heater (7); The solution outlet of the heat source tower heat pump system, the first regulating valve (2), the antifreeze booster pump (3), the filter (4), the low temperature liquid pipeline of the first solution heat exchanger (5), the second solution The low-temperature liquid pipeline of the heat exchanger (6) and the heating pipeline of the heater (7) are connected to each other in sequence; The heating pipeline of the heater (7) is also connected to each other with the antifreeze inlet of the forward osmosis device (8); the antifreeze outlet of the forward osmosis device (8) passes through the high-temperature liquid pipeline of the first solution heat exchanger (5) Finally, it is connected with the circulation loop formed by the heat source tower heat pump system and the second regulating valve (9); The draw liquid circulation system includes a third regulating valve (10), a third solution heat exchanger (11), a rectifier (12), a condenser (13), a tower top booster pump (14), a draw solution booster Pressure pump (15) and condensate water pump (16); On the one hand, the draw liquid outlet of the forward osmosis device (8) is connected to the draw liquid inlet of the rectifier (12) after passing through the third regulating valve (10) and the low-temperature liquid pipeline of the third solution heat exchanger (11) ; The tower top steam outlet of the rectifier (12) passes through the condensing pipe of the condenser (13), the tower top booster pump (14) and the draw solution booster pump (15) successively and the draw liquid of the forward osmosis device (8) The import is connected; The water outlet at the bottom of the rectifier (12) is successively connected with the high-temperature liquid pipeline of the condensate pump (16), the third solution heat exchanger (11) and the high-temperature liquid pipeline of the second solution heat exchanger (6); On the other hand, the draw solution outlet of the forward osmosis device (8) is connected to the draw solution inlet of the forward osmosis device (8) after passing through the draw solution booster pump (15). 2. the rectification regeneration device of heat source tower antifreeze solution according to claim 1, is characterized in that: when heat source tower heat pump system is open type, one end of the cooling pipeline of described condenser (13) is connected with heat source tower heat pump system and heat source tower heat pump system and The circulating loop formed by the second regulating valve (9) is connected; The other end of the cooling pipe of the condenser (13) is connected with the solution outlet of the heat source tower heat pump system through a fourth regulating valve (17); One end of the cooling pipe at the top of the tower in the rectifier (12) is connected with the circulation loop formed by the heat source tower heat pump system and the second regulating valve (9); The other end of the tower top cooling pipeline in the rectifier (12) is connected with the solution outlet of the heat source tower heat pump system through a fourth regulating valve (17). 3. the rectification regeneration device of heat source tower antifreeze solution according to claim 1, is characterized in that: when heat source tower heat pump system is closed type, one end of described condenser (13) cooling pipeline passes through the 4th adjusting valve ( 17) It is connected with the circulating solution outlet of the heat source tower heat pump system; The other end of the cooling pipe of the condenser (13) is connected with the circulating solution inlet of the heat source tower heat pump system; One end of the cooling pipe at the top of the tower in the rectifier (12) is connected with the circulating solution outlet of the heat source tower heat pump system through the fourth regulating valve (17); The other end of the tower top cooling pipe in the rectifier (12) is connected with the circulation solution inlet of the heat source tower heat pump system. 4. The rectification regeneration device for antifreeze solution of heat source tower according to claim 2 or 3, characterized in that: the antifreeze solution used in the working subsystem and the antifreeze circulation system is organic aqueous solution or inorganic aqueous solution; The water in the organic aqueous solution or the inorganic aqueous solution is a low boiling point component; The drawing solution used in the drawing liquid circulation system is selected from an organic aqueous solution that is completely miscible with water; The water in the fully water-miscible organic matter aqueous solution is a high boiling point component. 5. the rectification regeneration device of heat source tower antifreeze solution according to claim 4, it is characterized in that: between antifreeze inlet and antifreeze outlet and draw liquid inlet and draw liquid outlet in described forward osmosis device (8), pass Semi-permeable membrane isolation; The semi-permeable membrane selectively passes water and has a high retention of the antifreeze solution and the remaining components of the draw solution. 6. The rectification and regeneration device for heat source tower antifreeze solution according to claim 5, characterized in that: the heat source tower heat pump system is mainly composed of a heat source tower and a heat pump system. 7. The device for rectifying and regenerating the antifreeze solution of the heat source tower according to claim 6, characterized in that: the reboil heating pipe at the bottom of the rectifier (12) communicates with an external heat source.