阅读说明：本技术 一种自增压型溴化锂鼓泡吸收装置及其控制方法 (Self-pressurization type lithium bromide bubbling absorption device and control method thereof ) 是由 王刚 董佩文 刘芳 张群力 徐荣吉 于 2020-04-07 设计创作，主要内容包括：本发明公开了一种自增压型溴化锂鼓泡吸收装置及其控制方法,利用增压技术实现负压下鼓泡：在蒸汽系统中,通过变频增压泵给水蒸汽加压,使真空状态下水蒸汽在溴化锂溶液中成功鼓泡；微小压力单向平衡阀平衡压力：在气体排出管路入口设置微小压力单向平衡阀,快速排出未吸收蒸汽,平衡系统内压力,以保证吸收器内具有平稳的真空状态。本发明实现了真空状态下溴化锂溶液鼓泡吸收过程,为探索强化溴化锂吸收式制冷/热泵的热质传递性能,改善溴化锂吸收式制冷/热泵机组内部吸收效果提供了有效的途径和措施,对吸收式制冷/热泵系统性能的提升和结构小型化优化设计具有重要意义。(The invention discloses a self-pressurization type lithium bromide bubbling absorption device and a control method thereof, wherein bubbling under negative pressure is realized by utilizing a pressurization technology: in a steam system, water vapor is pressurized through a variable-frequency booster pump, so that the water vapor in a vacuum state is successfully bubbled in a lithium bromide solution; the micro pressure one-way balance valve balances pressure: the inlet of the gas discharge pipeline is provided with a micro pressure one-way balance valve, which can quickly discharge unabsorbed steam and balance the pressure in the system so as to ensure that the absorber has a stable vacuum state. The invention realizes the bubbling absorption process of the lithium bromide solution in a vacuum state, provides effective ways and measures for exploring and strengthening the heat and mass transfer performance of the lithium bromide absorption type refrigeration/heat pump unit and improving the internal absorption effect of the lithium bromide absorption type refrigeration/heat pump unit, and has important significance for the improvement of the performance of the absorption type refrigeration/heat pump system and the optimization design of the structure miniaturization.)

1. A self-pressurizing lithium bromide bubble absorber device, comprising:

a bubble absorber for completing a lithium bromide solution bubble absorption process;

the steam system is connected with the bubbling absorber through a gas introducing pipeline and a gas discharging pipeline and is used for providing steam required by the reaction;

the solution system is connected with the bubbling absorber through a bottom solution pipeline and a top solution pipeline and is used for storing, generating and circulating a concentrated solution and an absorbed dilute solution;

the cooling water system is connected with the bubble absorber through a bottom water path and a top water path and is used for providing cooling water with a certain temperature for the bubble absorber and taking away absorption heat;

and a nozzle is arranged at the joint of the bubbling absorber and the gas introducing pipeline.

2. The self-pressurization type lithium bromide bubble absorption device according to claim 1, wherein the bubble absorber comprises a cylindrical double-layer metal sleeve and a positioning fastener, the bottom of the cylindrical double-layer metal sleeve is vertically fixed by the positioning fastener, the cylindrical double-layer metal sleeve is internally divided into an inner pipe and an outer pipe, the inner pipe is used for generating lithium bromide bubble absorption reaction, and the outer pipe is used for circulating cooling water to absorb heat released in the lithium bromide bubble absorption process.

3. The self-pressurizing lithium bromide bubbling absorption device according to claim 2, wherein a plurality of thermocouples are arranged in the inner tube at different heights in the longitudinal direction, and a pressure gauge is arranged above the liquid level.

4. The self-pressurizing lithium bromide bubble absorption device according to claim 3, wherein the inner tube is provided with a plurality of sampling ports at different heights along the longitudinal direction.

5. The self-pressurizing lithium bromide bubbling absorption device according to claim 2, wherein the steam system comprises a vacuum pump, a steam generator, a pressurizer, a frequency converter, a flow regulator and a micro-pressure one-way balancing valve which are connected between a gas introducing pipeline and a gas discharging pipeline; the outlet of the vacuum pump is respectively connected with a steam generator and a micro pressure one-way balance valve, the micro pressure one-way balance valve is connected with a gas discharge pipeline, the outlet of the steam generator is respectively connected with a supercharger and a frequency converter, and the frequency converter, a flow regulator and a gas introduction pipeline are sequentially connected.

6. The self-pressurizing lithium bromide bubble absorption device according to claim 5, wherein a regulating valve is connected between the flow regulator and the gas introduction line.

7. The self-pressurizing lithium bromide bubbling absorption device according to claim 5, wherein the solution system comprises a liquid storage tank, a solution generator, a heat exchanger and a solution pump, and the bottom solution pipeline, the liquid storage tank, the solution generator, the heat exchanger, the solution pump and the top solution pipeline are connected in sequence.

8. The self-pressurization type lithium bromide bubbling absorption device according to claim 7, wherein the cooling water system comprises a constant-temperature water bath and a cooling water pump, and the bottom water path, the cooling water pump, the constant-temperature water bath and the top water path are sequentially connected.

9. The self-pressurizing lithium bromide bubbling absorption device according to claim 8, wherein the control method comprises the following steps:

starting a constant-temperature water bath and a cooling water pump to fill the outer pipe of the bubbling absorber with cooling water, and continuously circulating; after the prepared lithium bromide concentrated solution in the solution generator reaches a stable temperature in the heat exchanger, sending the lithium bromide concentrated solution into an inner tube of a bubbling absorber, and reserving a vacant space above the liquid level; at the moment, cooling water in the bubbling absorber is in a full liquid state, the lithium bromide solution is in a non-full liquid state, and a solution system pipeline is closed; starting a vacuum pump to vacuumize the self-pressurization type lithium bromide bubbling absorption device, so that the steam system and the bubbling absorber are in a vacuum state; turning off the vacuum pump, turning on the steam generator, generating steam in the steam generator by distilled water, pressurizing the steam by a supercharger and a frequency converter, regulating the flow by a flow regulator, bubbling the steam into a bubble absorber through a nozzle by a gas introduction pipeline, and carrying out bubble absorption reaction with a lithium bromide solution; unabsorbed water vapor bubbles overflow the liquid level and flow into a gas discharge pipeline, and then return to the steam generator through a micro pressure one-way balance valve;

and after the operation is finished, the steam system is closed, the lithium bromide dilute solution in the bubbling absorber is sent back to the liquid storage tank to wait for recycling, and the cooling water circulating pump is closed.

Technical Field

The invention relates to an absorber in an absorption refrigerator, in particular to a self-pressurization type lithium bromide bubbling absorption device and a control method thereof.

Background

The absorption refrigeration/heat pump technology plays an important role in the fields of refrigeration air-conditioning and waste heat recovery with the advantages of low-grade heat energy consumption and no pollution to the environment, the performance of the absorption refrigerator depends on the absorption performance of the absorber to a great extent, and the improvement of the physical structure and the absorption mode of the absorber is an effective means for improving the performance of the whole machine. Currently, there are two absorption modes of the absorber: falling film absorption and bubbling absorption, wherein bubbling absorption has the characteristics of large absorption area and good heat transfer effect because absorption gas is fully contacted with absorption solution in a bubble form, and the absorption effect is better than that of falling film absorption. Therefore, the bubble absorber has certain guiding significance for improving the performance of the absorption refrigeration/heat pump system and optimizing and designing the structure miniaturization.

Common absorption working media are lithium bromide solution and ammonia water. The ammonia bubbling absorption starts earlier, and is suitable for preparing cold energy below 0 ℃, but the safety cannot be ensured due to the toxic and high-pressure operation characteristics of the ammonia; the lithium bromide absorption refrigeration is suitable for preparing cold energy at the temperature of more than 0 ℃, but the development of lithium bromide bubbling absorption is restricted by the working condition that the absorption process needs to run in a vacuum state. With the intensive research of the pressurization absorption technology, the bubble buoyancy driving force of the bubbles in the solution is enhanced by compensating a part of electric energy, so that the bubbling absorption of the lithium bromide solution in a vacuum state becomes possible.

Disclosure of Invention

The invention provides a self-pressurization type lithium bromide bubbling absorption device and a control method thereof, which aim to improve the internal absorption effect of a lithium bromide absorption type refrigeration/heat pump unit.

In order to achieve the above purpose, the invention provides the following technical scheme:

a self-pressurizing lithium bromide bubble absorption device, comprising:

a bubble absorber for completing a lithium bromide solution bubble absorption process;

the steam system is connected with the bubbling absorber through a gas introducing pipeline and a gas discharging pipeline and is used for providing steam required by the reaction;

the solution system is connected with the bubbling absorber through a bottom solution pipeline and a top solution pipeline and is used for storing, generating and circulating a concentrated solution and an absorbed dilute solution;

the cooling water system is connected with the bubble absorber through a bottom water path and a top water path and is used for providing cooling water with a certain temperature for the bubble absorber and taking away absorption heat;

and a nozzle is arranged at the joint of the bubbling absorber and the gas introducing pipeline.

Preferably, the bubble absorber comprises a cylindrical double-layer metal sleeve and a positioning fastener, the bottom of the cylindrical double-layer metal sleeve is vertically fixed through the positioning fastener, the inside of the cylindrical double-layer metal sleeve can be divided into an inner pipe and an outer pipe, the inner pipe is used for generating lithium bromide bubble absorption reaction, and the outer pipe is used for circulating cooling water to absorb heat released in the lithium bromide bubble absorption process.

Preferably, the inner pipe is provided with a plurality of thermocouples at different heights along the longitudinal direction, and a pressure gauge is arranged above the liquid level.

Preferably, the inner tube is provided with a plurality of sampling ports at different heights along the longitudinal direction.

Preferably, the steam system comprises a vacuum pump, a steam generator, a supercharger, a frequency converter, a flow regulator and a micro-pressure one-way balance valve which are connected between a gas introduction pipeline and a gas discharge pipeline; the outlet of the vacuum pump is respectively connected with a steam generator and a micro pressure one-way balance valve, the micro pressure one-way balance valve is connected with a gas discharge pipeline, the outlet of the steam generator is respectively connected with a supercharger and a frequency converter, and the frequency converter, a flow regulator and a gas introduction pipeline are sequentially connected.

Preferably, a regulating valve is connected between the flow regulator and the gas introducing line.

Preferably, the solution system comprises a liquid storage tank, a solution generator, a heat exchanger and a solution pump, and the solution pipeline at the bottom end, the liquid storage tank, the solution generator, the heat exchanger, the solution pump and the solution pipeline at the top end are sequentially connected.

Preferably, the cooling water system comprises a constant-temperature water bath and a cooling water pump, and the bottom water path, the cooling water pump, the constant-temperature water bath and the top water path are sequentially connected.

The control method of the self-pressurization type lithium bromide bubbling absorption device is as follows:

starting a constant-temperature water bath and a cooling water pump to fill the outer pipe of the bubbling absorber with cooling water, and continuously circulating; after the prepared lithium bromide concentrated solution in the solution generator reaches a stable temperature in the heat exchanger, sending the lithium bromide concentrated solution into an inner tube of a bubbling absorber, and reserving a vacant space above the liquid level; at the moment, cooling water in the bubbling absorber is in a full liquid state, the lithium bromide solution is in a non-full liquid state, and a solution system pipeline is closed; starting a vacuum pump to vacuumize the self-pressurization type lithium bromide bubbling absorption device, so that the steam system and the bubbling absorber are in a vacuum state; turning off the vacuum pump, turning on the steam generator, generating steam in the steam generator by distilled water, pressurizing the steam by a supercharger and a frequency converter, regulating the flow by a flow regulator, bubbling the steam into a bubble absorber through a nozzle by a gas introduction pipeline, and carrying out bubble absorption reaction with a lithium bromide solution; unabsorbed water vapor bubbles overflow the liquid level and flow into a gas discharge pipeline, and then return to the steam generator through a micro pressure one-way balance valve;

and after the operation is finished, the steam system is closed, the lithium bromide dilute solution in the bubbling absorber is sent back to the liquid storage tank to wait for recycling, and the cooling water circulating pump is closed.

The invention provides a self-pressurization type lithium bromide bubbling absorption device and a control method thereof, which realize bubbling under negative pressure by utilizing a pressurization technology: in a steam system, water vapor is pressurized through a variable-frequency booster pump, so that the water vapor in a vacuum state is successfully bubbled in a lithium bromide solution; the micro pressure one-way balance valve balances pressure: the inlet of the gas discharge pipeline is provided with a micro pressure one-way balance valve, which can quickly discharge unabsorbed steam and balance the pressure in the system so as to ensure that the absorber has a stable vacuum state.

The self-pressurization type lithium bromide bubbling absorption device and the control method thereof provided by the invention realize the lithium bromide solution bubbling absorption process in a vacuum state, provide effective ways and measures for exploring and strengthening the heat and mass transfer performance of the lithium bromide absorption type refrigeration/heat pump and improving the internal absorption effect of the lithium bromide absorption type refrigeration/heat pump unit, and have important significance for the improvement of the performance of the absorption type refrigeration/heat pump system and the optimization design of the miniaturization structure.

Drawings

In order to more clearly illustrate the embodiments of the present application or technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings can be obtained by those skilled in the art according to the drawings.

Fig. 1 is a schematic structural diagram of a self-pressurization type lithium bromide bubbling absorption device according to an embodiment of the present invention.

Description of reference numerals:

1. a vacuum pump; 2. a steam generator; 3. a supercharger; 4. a frequency converter; 5. a flow regulator; 6. adjusting a valve; 7. a micro pressure one-way balance valve; 8. a liquid storage tank; 9. a solution generator; 10. a heat exchanger; 11. a solution pump; 12. a constant temperature water bath 13 and a cooling water pump; 14. a bubble absorber; 15. a nozzle; 16. a thermocouple; 17. a pressure gauge; 18. a temperature meter; 19. a sampling port; l1, gas introduction line; l2, gas vent line; l3, bottom solution line; l4, top solution line; l5, bottom waterway; l6, top water channel.

Detailed Description

In order to make the technical solutions of the present invention better understood, those skilled in the art will now describe the present invention in further detail with reference to the accompanying drawings.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrases "comprising … …" or "comprising … …" does not exclude the presence of additional elements in a process, method, article, or terminal that comprises the element. Further, herein, "greater than," "less than," "more than," and the like are understood to exclude the present numbers; the terms "above", "below", "within" and the like are to be understood as including the number.

As shown in fig. 1, the self-pressurizing lithium bromide bubbling absorption device is composed of a steam system, a solution system, a cooling water system and a bubbling absorber 14, the first three parts are respectively connected with the bubbling absorber 14, and the device can realize the effect of strengthening the heat and mass transfer characteristics in the solution convection absorption process in the lithium bromide solution absorber during operation.

The bubble absorber 14 comprises a cylindrical double-layer metal sleeve, upper and lower end cover sealing flanges and a positioning fastener, and is used for realizing the absorption process of the lithium bromide solution to bubbles. The bottom of the cylindrical double-layer metal sleeve is vertically fixed through a positioning fastener, the inside of the cylindrical double-layer metal sleeve can be divided into an inner tube and an outer tube, the inner tube is used for generating lithium bromide bubbling absorption reaction, and the outer tube is used for circulating cooling water to absorb heat released in the lithium bromide bubbling absorption process. The lithium bromide solution is in a non-liquid-full state in the bubble absorber, and the cooling water is in a liquid-full state in the bubble absorber. The inner tube is provided with a plurality of thermocouples 16 at different heights along the longitudinal direction, and a pressure gauge 17 is arranged above the liquid level to measure the temperature of the lithium bromide solution and the pressure in the tube. The inner tube is provided with a plurality of sampling ports 19 at different heights along the longitudinal direction so as to conveniently obtain lithium bromide solution samples. The bubbling absorber 14 is connected with the steam system, the solution system and the cooling water system through six pipelines, and comprises two gas pipelines, two solution pipelines and two water pipelines, namely a gas introduction pipeline L1, a gas discharge pipeline L2, a bottom end solution pipeline L3, a top end solution pipeline L4, a bottom end water pipeline L5 and a top end water pipeline L6. The inner tube of the absorber is connected with a gas introducing pipeline L1, a gas discharging pipeline L2, a bottom end solution pipeline L3 and a top end solution pipeline L4, the outer tube is connected with a bottom end water channel L5 and a top end water channel L6, a nozzle 15 is arranged at the joint of the lower end of the bubbling absorber 14 and the gas introducing pipeline L1, and the nozzle is replaceable in size and used for bubbling water vapor.

The steam system is connected with the bubbling absorber through a gas introducing pipeline L1 and a gas discharging pipeline L2, and is used for providing steam required by the reaction and ensuring that the steam meets the flow rate required by the test. The steam system comprises a vacuum pump 1, a steam generator 2, a supercharger 3, a frequency converter 4, a flow regulator 5, a regulating valve 6, a micro-pressure one-way balance valve 7, a valve and a pipeline which are connected with a gas introducing pipeline L1 and a gas discharging pipeline L2,

before the experiment begins, the vacuum pump 1 is started to vacuumize the system, so that the steam system and the bubble absorber 14 are in a vacuum state, the outlet of the vacuum pump 1 is respectively connected with the steam generator 2 and the micro-pressure one-way balance valve 7 through pipelines, and the micro-pressure one-way balance valve 7 is connected with the gas discharge pipeline L2. The steam generator 2 can heat and boil distilled water at low pressure to generate steam, and the outlet of the steam generator is respectively connected with the booster 3 and the frequency converter 4 through pipelines. The frequency converter 4, the flow regulator 5 and the gas introduction line L1 are connected in sequence by pipes. Preferably, a regulating valve 6 is connected between the flow regulator 5 and the gas introduction line L1 through a pipe.

The booster 3, the frequency converter 4 and the flow regulator 5 are responsible for regulating the steam flow to meet the test requirements, leading to the gas introduction line L1. The water vapor enters the bubble absorber 14 from the gas introduction line L1, and the unabsorbed water vapor bubbles overflow the liquid surface and flow into the gas discharge line L2, and return to the steam generator 2 through the minute pressure check balance valve 7. The micro pressure one-way balance valve 7 is used for balancing the pressure in the system, when the steam at the absorption end is not completely absorbed and overflows out of the liquid surface, the steam pressure at the absorption end is greater than that at the generation end, and the water vapor can pass through from the absorption end to the generation end in a one-way mode, so that a stable vacuum state is ensured in the bubbling absorber 14.

The solution system is connected with the bubble absorber 14 through a bottom solution pipeline L3 and a top solution pipeline L4, so as to realize the storage, generation and circulation of the concentrated solution and the absorbed dilute solution, and ensure that the concentrated solution can enter the bubble absorber 14 through the top solution pipeline L4 at the temperature required by the test. The solution system consists of a liquid storage tank 8, a solution generator 9, a heat exchanger 10, a solution pump 11, a valve and a pipeline. The bottom end solution pipeline L3, the liquid storage tank 8, the solution generator 9, the heat exchanger 10, the solution pump 11 and the top end solution pipeline L4 are connected in sequence through pipelines.

The liquid storage tank 8 is used for storing the reacted lithium bromide dilute solution and can discharge the solution after waiting for recycling, and the outlet of the liquid storage tank 8 is connected with the solution generator 9. The solution generator 9 is used for generating and storing a lithium bromide concentrated solution to be detected, and the outlet of the solution generator is connected with the heat exchanger 10. The heat exchanger 10 can adjust the concentrated solution to be measured to the required temperature of the test, and the outlet of the heat exchanger is connected with the solution pump 11 and leads to the top solution pipeline L4. Solution enters bubble absorber 14 from top solution line L4 and exits bottom solution line L3 back into reservoir 8.

The cooling water system is connected with the bubble absorber 14 through a bottom water path L5 and a top water path L6, and is used for providing cooling water with a certain temperature so as to absorb heat released in the lithium bromide bubble absorption process. The cooling water system consists of a constant-temperature water bath 12, a cooling water pump 13, a valve and a pipeline, wherein the bottom water path L5, the cooling water pump 13, the constant-temperature water bath 12 and the top water path L6 are sequentially connected through the pipeline. The bottom end waterway L5 and the top end waterway L6 are both connected with a temperature meter 18.

The constant temperature water bath 12 supplies cooling water to the bubble absorber 14, and the cooling water is sent into the absorber by the cooling water pump 13 through the bottom water path L5 and returns to the constant temperature water bath through the top water path L6.

The thermocouple 16, pressure gauge 17, and temperature gauge 18 are connected to an agilent and computer to acquire and process experimental data.

The valve and the pipeline are made of stainless steel, and heat insulation materials are paved outside the pipeline.

The self-pressurizing lithium bromide bubbling absorption device provided by the embodiment has the following control method:

the constant temperature water bath 12 and the cooling water pump 13 are started to make the cooling water continuously circulate after filling the outer tube of the bubbling absorber 14. After the prepared lithium bromide concentrated solution in the solution generator 9 reaches a stable temperature in the heat exchanger 10, the lithium bromide concentrated solution is sent into an inner pipe of the bubbling absorber 14, and a vacant space is reserved above the liquid level. At this time, the cooling water in the bubble absorber 14 is in a full liquid state, and the lithium bromide solution is in a non-full liquid state, and the solution system line is closed. The vacuum pump 1 is started to vacuumize the self-pressurization type lithium bromide bubbling absorption device, so that the steam system and the bubbling absorber 14 are in a vacuum state. And (2) closing the vacuum pump 1, starting the steam generator 2, generating water vapor in the steam generator 2 by distilled water, pressurizing the water vapor by a supercharger 3 and a frequency converter 4, regulating the flow by a flow regulator 5, bubbling the water vapor into the bubble absorber 14 through a nozzle 15 by a gas introduction pipeline L1, and carrying out bubble absorption reaction with the lithium bromide solution. The unabsorbed water vapor bubbles overflow the liquid surface and flow into the gas discharge line L2, passing through the minute-pressure check balance valve 7 and returning into the steam generator 2. During the reaction, the change of the pressure gauge value in the bubble absorber 14 is observed, and the steam flow is adjusted, so that the steam bubbles are absorbed by the solution as much as possible. And adjusting the flow speed and flow of the steam, the temperature change of the lithium bromide solution and the temperature change of the cooling water, and sampling at regular time to detect the concentration change of the solution.

After the operation is finished, the steam system is closed, the lithium bromide dilute solution in the bubbling absorber 14 is sent back to the liquid storage tank 8 for recycling, and the cooling water circulating pump 13 is closed.

The self-pressurization type lithium bromide bubbling absorption device and the control method thereof realize bubbling under negative pressure by utilizing a pressurization technology: in a steam system, water vapor is pressurized through a variable-frequency booster pump, so that the water vapor in a vacuum state is successfully bubbled in a lithium bromide solution; the micro pressure one-way balance valve balances pressure: the inlet of the gas discharge pipeline is provided with a micro pressure one-way balance valve, which can quickly discharge unabsorbed steam and balance the pressure in the system so as to ensure that the absorber has a stable vacuum state.

The self-pressurization type lithium bromide bubbling absorption device and the control method thereof realize the lithium bromide solution bubbling absorption process in a vacuum state, provide effective ways and measures for exploring and strengthening the heat and mass transfer performance of the lithium bromide absorption type refrigeration/heat pump unit and improving the internal absorption effect of the lithium bromide absorption type refrigeration/heat pump unit, and have important significance for the improvement of the performance of the absorption type refrigeration/heat pump system and the optimization design of structure miniaturization.

While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that the described embodiments may be modified in various different ways without departing from the spirit and scope of the invention. Accordingly, the drawings and description are illustrative in nature and should not be construed as limiting the scope of the invention.