CN100383477C - The second type of lithium bromide absorption heat pump for direct production of steam - Google Patents

Abstract

The present invention relates to a second lithium bromide absorption type heat pump for direct preparation of steam, which comprises an evaporator (1), an upright absorber (2), a generator (4), a condenser (5), a solution heat exchanger (3), a control system, pipelines, pumps and valves, wherein the pipelines, the pumps and the valves are used for connecting the components. The upright absorber comprises an absorber cylinder (16), an upright heat exchange tube bundle (14) of the absorber, an absorber tube sheet (12), an absorber upper header (10), an absorber lower header (15), a hot water supply water pipe (17), a liquid baffling device (9), a pipe outside solution distributing device (13) of concentrated solution and connecting pipelines, wherein the upright heat exchange tube bundle (14) of the absorber is arranged in an absorber cylinder (16) through the absorber tube sheet (12), the absorber upper header (10) and the absorber lower header (15) are respectively connected at the top part and the bottom part of the absorber cylinder (16), the hot water supply water pipe (17) is connected in the absorber lower header (15), the liquid baffling device (9) is arranged in the absorber upper header (10), and the pipe outside solution distributing device (13) of concentrated solution (13) is arranged at the upper part in the absorber cylinder (16). The present invention has the advantages of high heat exchange efficiency, low energy consumption, and simple and compact structure.

Description

The second type of lithium bromide absorption heat pump for direct production of steam

Technical field:

The invention relates to a second-type lithium bromide absorption heat pump unit. Specifically, it relates to a second-type lithium bromide absorption heat pump for directly producing steam. It belongs to the technical field of refrigeration equipment.

Background technique:

The previous second type lithium bromide absorption heat pump unit is shown in Figure 1. The unit shown in Figure 1 is a standard second-class lithium bromide absorption heat pump unit. The second type of lithium bromide absorption heat pump uses waste heat energy as the driving heat source, and obtains a higher temperature heat source under the condition of cooling, which is a kind of equipment that can effectively recover waste heat energy. The equipment is mainly composed of a generator 4, a condenser 5, an evaporator 1, an absorber 2, and a solution heat exchanger 3. The heating process is that the waste heat source heats the lithium bromide solution in the generator 4 to generate water vapor and increase the concentration. The generated water vapor is condensed by the cooling water in the condenser 5 to become refrigerant water, and the cooling water takes the heat of the refrigerant vapor out of the machine from the condenser 5, and the refrigerant water enters the evaporator through the condenser refrigerant pump 7 The refrigerant water liquid bag is driven into the surface of the heat transfer tube of the evaporator by the refrigerant circulation pump 6 of the evaporator, absorbs the heat of the waste heat source and evaporates, and the concentrated solution in the generator enters through the solution heat exchanger 3 through the concentrated solution pump 8 The absorber 2 absorbs the refrigerant vapor from the evaporator 1. The heat generated in the absorption process heats the fluid in the absorber tube, so that the temperature of the hot water in the tube rises, and it is used in the hot place.

When the second type of lithium bromide absorption heat pump unit is used to produce steam, as shown in Figure 2, the hot water enters the absorber 2 through the hot water circulation pump 20, and then sprays in the steam flasher 19, and part of the liquid is absorbed. The heat of the liquid itself flashes, and the generated steam passes through the liquid retaining device 9 and is transported to a hot place for use. After the liquid without flashing is cooled down and mixed with replenishing water, it is circulated through the hot water circulation pump to continuously generate steam. This kind of device system needs to add steam flasher and hot water circulation pump. The system is relatively complicated and the initial investment is large. Since steam is generated by flashing and cooling the hot water itself in the steam flasher, a large amount of hot water circulation is required, the power consumption of the hot water circulation pump is high, and the operating cost is relatively high.

Invention content:

The object of the present invention is to overcome the above disadvantages, and provide a second-type lithium bromide absorption heat pump with high heat exchange efficiency, low energy consumption, simple and compact structure, and direct production of steam.

The object of the present invention can be achieved through the following three schemes:

Option 1: A second-type lithium bromide absorption heat pump that directly produces steam, including: evaporator, absorber, generator, condenser, solution heat exchanger, control system and pipelines connecting various components, pumps, valves , characterized in that: the absorber is a vertical absorber, including: absorber cylinder, absorber vertical heat exchange tube bundle, absorber tube sheet, absorber upper tube box, absorber lower tube box, hot water Downpipe, hot water replenishment pipe, liquid retaining device, liquid distribution device outside concentrated solution pipe, connecting pipes, valves, and absorber cylinder are vertically arranged, and the vertical heat exchange tube bundle of the absorber is arranged on the absorber through the absorber tube plate. In the shell of the absorber, the upper pipe box of the absorber and the lower pipe box of the absorber are respectively connected to the top and bottom of the absorber cylinder. The water supply pipe is connected to the lower pipe box of the absorber, the liquid blocking device is installed in the upper pipe box of the absorber, and the liquid distribution device outside the concentrated solution pipe is arranged on the upper part of the absorber cylinder. The concentrated solution is evenly distributed outside the vertical heat exchange tube bundle of the absorber through the liquid distribution device outside the concentrated solution pipe to form a solution liquid film. Hot water in the vertical heat transfer tube of the absorber is heated and boiled by the solution outside the tube to generate steam, enters the upper tube box of the absorber, and is transported to the steam using place through the liquid blocking device. During operation, the hot water descending pipe is below the hot water surface of the upper tube box of the absorber. Because the hot water in the vertical heat exchange tube of the absorber entrains steam bubbles, the density decreases and rises rapidly to form an ascending pipe, while the hot water descends. The hot water density of the tube is higher than that of the riser tube, and the hot water in the upper tube box flows to the lower tube box by the pressure difference, forming convection, increasing the flow rate of hot water in the vertical heat exchange tube bundle of the absorber, and improving the heat exchange effect. Since the hot water is continuously vaporized, by controlling the liquid level in the upper tube box of the absorber, the hot water replenishment is carried out at the bottom of the lower tube box of the absorber, so that the hot water is always within a certain liquid level range, so that the hot water replenishment volume and steam Occurrence balance. The vertical absorber of the present invention has the function of combining the original hot water pipeline, the steam flasher and the absorber. The structure of the present invention does not use a hot water pump, and relies on the principle of thermosiphon to make the hot water reach natural convection, which improves the The heat exchange effect reduces the heat transfer area and energy consumption, simplifies the structure, and makes the overall structure simple and compact. The initial investment and operating costs of the heat pump itself and the external system are greatly reduced.

Option 2. On the basis of Option 1, the hot water downcomer is canceled, and a vertical partition device is added on the upper tube plate of the absorber to separate the liquid phase area of the upper tube box of the absorber, forming high and low liquid levels on both sides , make hot water replenishment on one side of the upper tube box of the absorber, so that the hot water level on this side is high, so that the hot water continues to drop in the vertical heat exchange tube bundle of the absorber, and the other side has no replenishment, the heat The water level is low, and the forced flow is generated in the heat transfer tube by the replenishment of hot water. The heat transfer tube on the hot water replenishment side becomes a downcomer, and the other side forms a riser tube. The hot water in the vertical heat transfer tube of the absorber is heated and boiled by the solution outside the tube to generate steam, which rises rapidly and flows into the steam chamber of the upper tube box of the absorber, and is transported to the steam using place through the liquid blocking device.

Scheme three, on the basis of scheme one, cancel the hot water downpipe between the upper and lower pipe boxes of the absorber. The inlet of the hot water replenishment pipe is set at the lower tube box of the absorber, and the hot water forms a forced flow from bottom to top in the vertical heat transfer tube of the absorber.

Description of drawings:

Fig. 1 is a schematic diagram of a conventional second type lithium bromide absorption heat pump unit.

Fig. 2 is a schematic diagram of producing steam by adopting the second type lithium bromide absorption heat pump unit in the past.

Fig. 3 is a schematic diagram of the second type lithium bromide absorption heat pump scheme 1 for directly producing steam in the present invention.

Fig. 4 is a schematic diagram of the second type lithium bromide absorption heat pump scheme 2 for directly producing steam in the present invention.

Detailed ways:

Scheme 1: The unit shown in Figure 3, the unit is composed of an evaporator 1, a vertical absorber 2, a generator 4, a condenser 5, a solution heat exchanger 3, a refrigerant circulation pump 6, and a condenser refrigerant pump 7 , a concentrated solution pump 8, a control system (not shown in the figure) and pipelines and valves connecting various components constitute a second-type lithium bromide absorption heat pump unit that directly produces steam. The vertical absorber 2 is composed of a liquid blocking device 9, an absorber upper tube box 10, a hot water downcomer 11, an absorber tube plate 12, a liquid distribution device 13 outside the concentrated solution tube, an absorber vertical heat exchange tube bundle 14, and an absorber The lower tube box 15, the absorber cylinder 16, the hot water supply pipe 17 and other corresponding connecting pipelines, valves, etc. constitute. The absorber cylinder 16 is vertically arranged, the absorber vertical heat exchange tube bundle 14 is arranged in the absorber cylinder 16 through the absorber tube sheet 12, the absorber upper tube box 10 and the absorber lower tube box 15 are connected to the absorber The top and bottom of cylinder body 16, hot water replenishment pipe 17 is connected in absorber lower pipe box 15, and absorber upper pipe box 10 and absorber lower pipe box 15 are connected by hot water downpipe 11. The hot water downpipe 11 can be one or several. The liquid blocking device 9 is installed in the upper tube box 10 of the absorber, and the liquid distribution device 13 outside the concentrated solution pipe is arranged in the upper part of the absorber cylinder 16, and communicates with the concentrated solution outlet of the solution heat exchanger 3 . When the second type of lithium bromide absorption heat pump unit is in operation, the concentrated solution of the generator is transported to the upper part of the cylinder of the vertical absorber 2 through the concentrated solution pump 8 through the solution heat exchanger 3, and the concentrated solution is discharged through the liquid distribution device 13 outside the concentrated solution pipe. Evenly distributed to the outside of the vertical heat exchange tube bundle 14 of the absorber, forming a concentrated solution liquid film outside the heat exchange tube, absorbing the refrigerant vapor from the evaporator 1, heating the hot water in the heat exchange tube, and falling to the The lower part of the absorber cylinder returns to the generator 4 through the solution heat exchanger 3 . According to the liquid level in the upper tube box 10 of the absorber, water is continuously replenished in the lower tube box 15 of the absorber to control the amount of hot water within a certain liquid level range. The hot water in the vertical heat exchange tube bundle 14 of the absorber absorbs the heat of the solution outside the tube, and a part of the hot water vaporizes to generate water vapor. The hot water entrains steam bubbles, and the density decreases and rises rapidly to flow into the upper tube box 10 of the absorber. In the steam chamber, the saturated water vapor generated is delivered to the place where the steam is used through the liquid blocking device 9 installed in the upper pipe box 10 of the absorber. The unvaporized hot water enters the hot water downcomer 11. Since there are no bubbles in the hot water downcomer, the density is higher than that of the vapor-liquid mixture in the vertical heat exchange tube bundle 14 of the absorber, forming a pressure difference and flowing into the downcomer box 15 of the absorber. Inside, a natural backflow is formed.

Scheme 2 is shown in Figure 4. On the basis of Scheme 1, the hot water downcomer 11 is canceled, and a vertical partition device 11 is added on the upper tube plate of the absorber to separate the liquid phase area of the upper tube box 10 of the absorber. For high and low liquid levels, hot water replenishment is carried out on one side of the upper tube box 10 of the absorber.

Scheme three, on the basis of scheme one, cancel the hot water downpipe 11 between the upper and lower pipe boxes of the absorber. The inlet of the hot water replenishment pipe is arranged at the lower pipe box 15 of the absorber, and the hot water forms a forced flow from bottom to top at the vertical heat transfer pipe 14 of the absorber.

The above scheme is applicable to parallel flow and series flow of waste heat sources. The evaporator, generator, and condenser can be arranged horizontally or vertically. In the overall arrangement, the generator and condenser can be arranged on the evaporator and the absorber, or on the side of the evaporator and the absorber. Lower or separate. Generators and condensers can be single-stage or multi-stage.

Claims (5)

1. A second type lithium bromide absorption heat pump for directly producing steam, comprising: evaporator (1), absorber (2), generator (4), condenser (5), solution heat exchanger (3) , the control system and the pipelines, pumps and valves connecting the various parts, the absorber (2) is a vertical absorber, comprising: the absorber cylinder (16), the absorber vertical heat exchange tube bundle (14), Absorber tube plate (12), absorber upper tube box (10), absorber lower tube box (15), hot water replenishment pipe (17), liquid blocking device (9), liquid distribution device outside concentrated solution pipe (13 ) and connecting pipelines, the absorber cylinder (16) is vertically arranged, and the absorber vertical heat exchange tube bundle (14) is arranged in the absorber cylinder (16) through the absorber tube sheet (12). The tube box (10) and the absorber lower tube box (15) are respectively connected to the top and bottom of the absorber cylinder (16), the liquid blocking device (9) is installed in the absorber upper tube box (10), and the concentrated solution pipe The outer liquid distribution device (13) is arranged on the inner upper part of the absorber cylinder (16), and it is characterized in that a vertical partition device (11) is added to the upper tube sheet (12) of the absorber, and the hot water supply pipe (17 ) into one side of the upper tube box (10) of the absorber. 2. A second-type lithium bromide absorption heat pump for directly producing steam according to claim 1, characterized in that: the waste heat source of the heat pump is a parallel process or a series process. 3. A second-type lithium bromide absorption heat pump for directly producing steam according to claim 1, characterized in that: the evaporator, generator, and condenser of the heat pump are arranged horizontally or vertically as a whole . 4. A second-type lithium bromide absorption heat pump for directly producing steam according to claim 1, characterized in that: the generator and condenser of the heat pump are arranged above or below the evaporator and the absorber or placed separately . 5. A second-type lithium bromide absorption heat pump for directly producing steam according to claim 1, characterized in that: the generator and condenser of the heat pump are single-stage or multi-stage.

Images