CN105605823A - Double-effect waste heat complementary combustion type lithium bromide absorption refrigerator - Google Patents

Abstract

The invention discloses a double-effect waste heat supplementary combustion lithium bromide absorption refrigerator, which comprises a high-pressure generator, a low-pressure generator, a condenser, an evaporator, an absorber, a high-temperature solution heat exchanger and a low-temperature solution heat exchanger; The solution outlet of the absorber and the solution inlet of the absorber are connected through pipelines through the high-temperature solution heat exchanger, low-pressure generator, and low-temperature solution heat exchanger; Connected; the evaporator refrigerant water and the absorber solution merge into a dilute solution outlet, which is connected to the solution inlet of the high-pressure generator through the solution pump, low-temperature solution heat exchanger, and high-temperature solution heat exchanger; the cold water at the outlet of the air handler is cooled by the evaporator The inlet flows back to the water return port of the air handler through the internal pipe; the cold water at the outlet of the cooling tower flows from the cold water inlet of the absorber, through its internal pipe, cold water outlet, condenser cold water inlet, and the internal pipe of the condenser to the cooling tower return water port .

Description

A double-effect waste heat supplementary combustion lithium bromide absorption refrigerator

Technical field:

The invention relates to a double-effect waste heat supplementary combustion type lithium bromide absorption refrigerator, which belongs to the technical field of absorption refrigerators.

Background technique:

Micro gas turbines are widely used in the field of power generation, and the utilization of residual heat is also the focus of everyone's attention. In terms of waste heat refrigeration, a lot of research has been carried out at home and abroad. The air-cooled refrigerator has a large volume, and the technology is still immature. When the ambient temperature is too high, it is prone to problems such as crystallization of lithium bromide solution, and has not yet been practically applied. Therefore, it basically focuses on the research and development of water-cooled refrigerators. Japanese Yazaki (Yazaki), American Carrier (Carrier) and other manufacturers have successively developed 35kW hot water type single-effect lithium bromide refrigerators (with CapstoneC30), flue gas/direct-fired lithium bromide refrigerators and other products for supporting micro gas turbines. In addition, the American PowerHouse company has carried out the research and prototype development of the ammonia-water absorption refrigerator directly driven by the flue gas. The first prototype is said to have a energy efficiency ratio (COP) of more than 1.0, but the waste heat recovery is small, and the cooling capacity is only lithium bromide. Half of the refrigerator, the application value is low. In China, manufacturers of lithium bromide refrigerators such as Changsha Yuanda have introduced micro gas turbines and carried out related technical research. Micro gas turbines such as 60 have developed waste heat type single-effect bromine coolers, but these refrigerators heat the lithium bromide solution through an intermediate medium such as water or heat transfer oil, and the intermediate heat exchange link reduces the thermal efficiency.

On the whole, the waste heat bromine chillers supporting micro gas turbines at home and abroad are all water-cooled single-effect models, with simple refrigeration cycle process, low manufacturing cost and small host volume. But its refrigeration energy efficiency ratio is low, the highest is 0.7, and the cooling load is large at the same time, and the cooling water consumption is about 40% higher than that of the double-effect machine. However, the cooling tower is large and difficult to arrange under the condition of limited space. Furthermore, micro gas turbines are mainly used for power generation, and the range of power generation varies widely. How to ensure the stable output of cooling capacity when the waste heat is unstable is also an urgent problem to be solved.

Invention content:

The object of the present invention is to solve the problem of large volume and weight and unstable cooling capacity of the waste heat utilization type refrigerator used in conjunction with the micro gas turbine, and proposes a double-effect waste heat supplementary combustion type lithium bromide absorption refrigerator.

In order to achieve the above object, the present invention adopts following technical scheme to realize:

A double-effect residual heat supplementary combustion lithium bromide absorption refrigerator is characterized in that it includes a high-pressure generator, a low-pressure generator, a condenser, an evaporator, an absorber, a high-temperature solution heat exchanger, and a low-temperature solution heat exchanger; wherein,

The solution outlet of the high-pressure generator is connected with the solution inlet of the low-pressure generator through a pipeline, and the high-temperature solution heat exchanger is passed through; the refrigerant water vapor outlet of the high-pressure generator is connected with the refrigerant water vapor inlet of the low-pressure generator through a pipeline;

The solution outlet of the low-pressure generator is connected to the solution inlet of the absorber through a pipeline, and the low-temperature solution heat exchanger is passed between; area; the refrigerant water outlet of the low-pressure generator and the refrigerant water inlet of the condenser are connected by pipes; there is also a channel for flowing water vapor between the low-pressure generator and the condenser, and the position of the channel is higher than the solution area;

The refrigerant water outlet of the condenser is connected with the refrigerant water inlet of the evaporator through pipes;

The refrigerant water outlet of the evaporator and the solution outlet of the absorber merge together to form a dilute solution outlet, and pass through the solution pump, low-temperature solution heat exchanger, and high-temperature solution heat exchanger, and connect with the solution inlet of the high-pressure generator. , the dilute solution outlet is connected with the solution inlet of the low-pressure generator through the solution pump through the pipeline;

The cold water at the water outlet of the air handler flows from the cold water inlet of the evaporator, through the internal pipe of the evaporator, and flows from the cold water outlet of the evaporator to the water return port of the air handler;

The cold water at the water outlet of the cooling tower flows from the cold water inlet of the absorber, through the inner pipe of the absorber, from the cold water outlet of the absorber to the cold water inlet of the condenser, then through the inner pipe of the condenser, and finally flows from the cold water outlet of the condenser to the return water port of the cooling tower .

A further improvement of the present invention is that it also includes a vacuum pump, which is arranged outside the vacuum ports of the condenser and the evaporator.

The further improvement of the present invention is that it also includes an automatic crystal melting sleeve, which is arranged outside the pipe connecting the solution pump and the solution inlet of the low-pressure generator.

Compared with the prior art, the present invention has the following beneficial effects:

The invention can greatly reduce volume weight and stabilize cooling capacity output. At the same time, the scheme of solution series flow, single pump and semi-immersed evaporator is adopted, which improves the characteristics of easy crystallization of bromine chiller solution and easy pollution of refrigerant, combined with the technology of automatic frequency conversion control of high liquid level of solution pump, reducing operation and maintenance requirements . The refrigerating machine of the invention uses water as a refrigerant and an aqueous solution of lithium bromide as an absorbent to operate in a vacuum state. Compared with traditional vapor compression refrigeration, it has fewer moving parts, less noise, stable operation, and no leakage of volatile working fluid that causes environmental pollution. The additional supplementary combustion system can not only meet the user's cooling demand under various complex conditions, but also greatly improve the overall efficiency of the micro gas turbine unit.

The refrigerator converts the heat energy in the exhaust smoke of the micro gas turbine unit into the cold energy of the air-conditioning water, which is transported to the air handler through the air-conditioning circulation pump, and exchanges energy with the hot air discharged from the room, so that the temperature and humidity of the air are reduced and then transported to the user.

The refrigeration principle of the lithium bromide absorption refrigerator is fundamentally the principle of using water evaporation to absorb heat. In the high-pressure generator and low-pressure generator, the water evaporates and absorbs the heat of the external heating source to generate the power of the system cycle; in the evaporator, the water evaporates and absorbs the heat brought by the air-conditioning water from the air-conditioning room, so that the air-conditioning water cools down, so as to achieve The purpose of air conditioning room cooling. The function of other components is to assist in the realization of water circulation (condenser, absorber), or to recover heat to minimize energy consumption (high temperature solution heat exchanger, low temperature solution heat exchanger).

Description of drawings:

Fig. 1 is a flow chart of the water-cooled double-effect solution series lithium bromide absorption refrigeration of the present invention.

In the figure: 1 is a high-pressure generator, 2 is a low-pressure generator, 3 is a condenser, 4 is an evaporator, 5 is an absorber, 6 is a high-temperature solution heat exchanger, 7 is a low-temperature solution heat exchanger, and 8 is a solution pump , 9 is a vacuum pump, and 10 is an automatic crystal melting sleeve.

detailed description:

Further description will be made below in conjunction with the embodiments in the accompanying drawings:

As shown in Figure 1, the refrigerator of the present invention is mainly composed of a high-pressure generator 1, a low-pressure generator 2, a condenser 3, an evaporator 4, an absorber 5, a high-temperature solution heat exchanger 6, a low-temperature solution heat exchanger 7, a solution It is composed of pump 8, vacuum pump 9, automatic crystal melting casing 10, pipelines and regulating valves.

Described high-pressure generator 1, its solution outlet and low-pressure generator 2 solution inlets are connected by pipeline, therebetween passes high-temperature solution heat exchanger 6; High-pressure generator 1 refrigerant steam outlet and low-pressure generator 2 refrigerant water vapor inlets connected by pipes.

Described low-pressure generator 2, its solution outlet is connected with absorber 5 solution inlets through pipeline, passes through low-temperature solution heat exchanger 7 therebetween; 2 is connected internally and passes through the solution area; the refrigerant water outlet of the low-pressure generator 2 and the refrigerant water inlet of the condenser 3 are connected by pipes; there is also a channel for flowing water vapor between the low-pressure generator 2 and the condenser 3 , the channel position should be higher than the solution area.

In the condenser 3, its refrigerant water outlet is connected to the refrigerant water inlet of the evaporator 4 through pipes.

Described evaporator 4, its refrigerant water outlet and absorber 5 solution outlet merge together, form the dilute solution outlet together, and pass through solution pump 8, low-temperature solution heat exchanger 6, high-temperature solution heat exchanger 7, and high pressure The solution inlet of generator 1 is connected.

The vacuum pump 9 is arranged outside the vacuum ports of the condenser 3 and the evaporator 4 .

The automatic crystal melting sleeve 10 is arranged outside the pipe connecting the solution pump 8 and the solution inlet of the low pressure generator 2 .

The cold water at the water outlet of the air handler flows from the evaporator 4 cold water inlet through the evaporator 4 internal pipeline to the return water outlet of the air handler by the evaporator 4 cold water outlet.

The cold water at the water outlet of the cooling tower flows from the cold water inlet of the absorber 5, through the inner pipe of the absorber 5, from the cold water outlet of the absorber 5 to the cold water inlet of the condenser 3, then through the inner pipe of the condenser 3, and finally flows from the cold water outlet of the condenser 3 to the return port of the cooling tower.

The internal working process of the lithium bromide absorption refrigerating machine is divided into a refrigerant water process and a solution process, and the two processes have both independent stages and mutually integrated stages, which are described in detail as follows.

1) The waste heat flue gas flows through the flue gas channel of the high-pressure generator, heating the dilute lithium bromide solution in the high-pressure generator, and the dilute lithium bromide solution boils to generate refrigerant water vapor. The generated refrigerant water vapor is transported to the low-pressure generator through the closed steam pipe (passing through the heat exchange tube of the low-pressure generator), and the lithium bromide solution outside the heat exchange tube is heated, and the water vapor of the low emission solution is condensed into a high temperature liquid refrigerant The refrigerant water and the refrigerant water vapor generated by the boiling of the low-pressure generator enter the condenser respectively, and are condensed by the cooling water in the condenser pipe to become liquid refrigerant water at room temperature. The pressure of normal temperature liquid refrigerant water decreases after throttling, evaporates at low temperature in the evaporator, absorbs the heat brought by the air-conditioning water in the heat exchange tube, and produces a cooling effect.

2) In the high-pressure generator, the dilute solution is heated and boiled by the flue gas to generate refrigerant water vapor, the pressure rises, and the concentration of water loss of the solution increases at the same time, and a solution with a higher concentration is formed near the outlet of the high-pressure generator solution—called intermediate solution. Under the action of pressure difference, the intermediate solution enters the low-pressure generator after throttling and depressurization, and is heated and boiled by the refrigerant water vapor in the heat exchange tube, and further loses water and concentrates to form a concentrated solution near the solution outlet of the low-pressure generator, and the concentrated solution enters the absorption The evaporator absorbs the low-temperature refrigerant water vapor generated by the evaporation of the evaporator, and becomes a dilute solution again, which is transported by the solution pump to the high-pressure generator for heating, thus completing a cycle. Place a heat exchanger at the outlet of the high-pressure generator and the outlet of the low-pressure generator, namely, a high-temperature solution heat exchanger and a low-temperature solution heat exchanger, to recover the heat of the solution and feed the solution into the high-pressure generator and the low-pressure generator respectively. Preheating is performed to improve the overall economical performance of the system.

The operation control requirements of the refrigerator are very high. In order to reduce the difficulty of operation, corresponding control programs are designed for the start-up, normal operation, dilution operation before shutdown, and fault alarm safety protection of the unit, which realizes the fully automatic operation of the unit without manual labor. on duty. Among them, the liquid level control of the high-fat solution adopts four groups of electrodes to be divided into low, normal, high and ultra-high liquid level levels. Through the frequency conversion of the solution pump, the stable control of the liquid level is realized by using the dichotomy method combined with liquid level prediction and other algorithms to ensure the circulation. parameter stability.

Claims (3)

1. a double-effect waste heat supplementary combustion type lithium bromide absorption refrigerator is characterized in that, comprises high pressure generator (1), low pressure generator (2), condenser (3), evaporator (4), absorber ( 5), high temperature solution heat exchanger (6) and low temperature solution heat exchanger (7); wherein, The solution outlet of the high-pressure generator (1) is connected to the solution inlet of the low-pressure generator (2) through a pipeline, and the high-temperature solution heat exchanger (6) is passed through in between; the refrigerant water vapor outlet of the high-pressure generator (1) is connected to the low-pressure generator (2) The refrigerant water vapor inlet is connected through a pipeline; The solution outlet of the low-pressure generator (2) is connected to the solution inlet of the absorber (5) through a pipe, and passes through the low-temperature solution heat exchanger (7); the refrigerant water vapor inlet of the low-pressure generator (2) is connected to the refrigerant water outlet The low-pressure generator (2) is connected through the pipeline and passes through the solution area; the refrigerant water outlet of the low-pressure generator (2) is connected with the refrigerant water inlet of the condenser (3); the low-pressure generator (2) ) and the condenser (3) also have a passage for flowable water vapor, and the passage position is higher than the solution area; The refrigerant water outlet of the condenser (3) is connected to the refrigerant water inlet of the evaporator (4) through a pipeline; The refrigerant water outlet of the evaporator (4) and the solution outlet of the absorber (5) merge together to form a dilute solution outlet, and pass through the solution pump (8), the low-temperature solution heat exchanger (7), and the high-temperature solution heat exchange A device (6) is connected to the solution inlet of the high-pressure generator (1), and at the same time, the diluted solution outlet is connected to the solution inlet of the low-pressure generator (2) through a pipeline through a solution pump (8); The cold water at the water outlet of the air handler flows from the cold water inlet of the evaporator (4), through the internal pipe of the evaporator (4), and flows from the cold water outlet of the evaporator (4) to the water return port of the air handler; The cold water at the water outlet of the cooling tower flows from the cold water inlet of the absorber (5), through the internal pipeline of the absorber (5), from the cold water outlet of the absorber (5) to the cold water inlet of the condenser (3), and then passes through the inside of the condenser (3) The pipeline finally flows from the cold water outlet of the condenser (3) to the water return port of the cooling tower. 2. A kind of double-effect residual heat supplementary combustion type lithium bromide absorption refrigerator according to claim 1, is characterized in that, also comprises vacuum pump (9), and it is arranged on the vacuum of condenser (3) and evaporator (4) outside the mouth. 3. A kind of double-effect waste heat supplementary combustion type lithium bromide absorption refrigerator according to claim 1, is characterized in that, also comprises automatic melting crystal casing (10), and it is arranged on solution pump (8) and low pressure generator (2) The solution inlet is connected to the outside of the pipeline.