CN1292218C - Non-pump sorption refrigerator - Google Patents

Abstract

The invention relates to the fields of refrigeration, solar energy and other waste heat utilization, more precisely, it is a pumpless absorption refrigerator, comprising a thermosiphon pump, a condenser (9), an evaporator (12), an absorber (14), a liquid storage The tank (16), the thermosiphon pump is connected to the inlet end of the condenser (9) through the refrigerant gas outlet pipe (6), the outlet end of the condenser (9) is connected to the evaporator (12), and the outlet end of the condenser (9) Divide into two small tubes, one straight down, connected to the front of the evaporator, the other up first and then bend down again. It has the advantages of high heat utilization rate and high cooling capacity per unit volume of equipment.

Description

A pumpless absorption refrigerator

technical field

The invention relates to the fields of refrigeration, solar energy and other waste heat utilization, and more precisely relates to a pumpless absorption refrigerator.

Background technique

Refrigeration machinery is a kind of machinery commonly used at present. Whether it is industrial or civil, a large number of such machinery are needed. At present, the commonly used refrigeration machinery is a compression refrigerator, but compression refrigeration needs to consume electric energy, and the refrigerant may produce greenhouse effect gases and gases that destroy the ozone layer of the atmosphere. On the other hand, with the development of production and the improvement of people's living standards, more and more electricity is consumed by air-conditioning refrigeration and other refrigeration, which has caused a series of problems such as power shortage, energy shortage and environmental pollution. People are paying more and more attention to the use of clean energy and renewable energy, and are eager to develop various refrigeration methods and refrigeration machines that do not consume electricity, have no greenhouse effect gases, and destroy atmospheric ozone layer gases.

Diffusion absorption refrigeration system is an environmentally friendly refrigeration method that uses solar energy and other waste heat to obtain cooling capacity. It has no compressor, does not produce greenhouse effect gases, and does not destroy the ozone layer of the atmosphere, so it has been widely valued. However, there are still problems such as low heat utilization rate, poor performance of the key component thermosiphon pump system, high riser height, and small cooling capacity per unit volume of equipment. The above problems have seriously restricted the commercial application of diffusion refrigeration systems. .

Contents of the invention

The object of the present invention is to provide an environment-friendly diffusion-absorption refrigeration device with high heat utilization rate and high refrigeration capacity per unit volume.

The beneficial effects of the present invention are achieved through the following schemes:

The invention includes a thermosiphon pump, a condenser, an evaporator, an absorber, and a liquid storage tank. The thermosiphon pump is connected to the inlet end of the condenser through a refrigerant gas outlet pipe, and the outlet end of the condenser is connected to the evaporator. The end is divided into two small tubes, one is directly down, connected to the front end of the evaporator, the other is up first and then bent down, and the inside is uncondensed refrigerant gas and non-condensable diffusion gas. It is connected with the gas outlet of the evaporator, and then continues downward, enters the solution storage tank under the action of pressure difference and is connected to the inlet port of the liquid storage tank together; the liquid storage tank has two outlets, the first side outlet and the concentrated solution inlet The inlet of the tube is connected, and the outlet on the second side is connected to the inlet of the absorber tube; at the outlet of the absorber tube, a small tube enters from the back end of the evaporator to the front end, and the small tube mainly contains unabsorbed diffused gas. The other outlet is connected to the outlet pipe of the dilute solution, and the outlets of the inlet pipe of the concentrated solution and the outlet pipe of the dilute solution are respectively connected to a thermosiphon pump. In the absorber tube, the dilute solution flows all the way down along the pipeline, while the mixed gas from the evaporator and condenser goes all the way up from the lower end of the absorber pipeline, and the two flow in counter-phase contact, and the refrigerant gas is basically absorbed , the dilute solution becomes a concentrated solution and enters the liquid storage tank.

In this way, due to the partial pressure of the diffused gas at the front end of the evaporator, the total pressure of the condenser and the total pressure of the evaporator are basically equal, but the condensed refrigerant is still continuously evaporated to achieve the purpose of refrigeration.

The above-mentioned thermosyphon pump is a variable annular gap triple casing type thermosyphon pump, which is based on a seamless inner tube and is composed of an inner tube, a partition tube and an outer tube. The lower end is connected with the concentrated solution inlet pipe; the outer pipe is welded on the outside of the separating pipe, the upper end is connected with the refrigerant gas outlet pipe, and the lower end is connected with the dilute solution outlet pipe.

In order to further improve the performance of the riser in the thermosyphon pump, the cross-section of the riser annulus is radially asymmetric. Due to the radial asymmetry, the maximum velocity in the short axis direction of the annular passage and the maximum velocity in the long axis direction The maximum speed is not equal, the thrust caused by the speed difference can push the fluid from the short axis direction to the long axis direction, the resulting secondary flow can reduce the thickness of the lower layer of laminar flow, strengthen the heat transfer effect, and promote the evaporation and boiling of the solution , and then improve the lifting performance of the riser. The inner tube of the variable annular gap triple casing thermosiphon pump is oval.

In order to enhance the heat transfer effect of the external heat source of the thermosiphon pump, fins are provided on the inner side of the inner tube, and the thickness gradually becomes thicker from the center to the outside. The heat flux on the surface remains basically equal, which is conducive to the transfer of heat.

In order to enhance the boiling heat transfer effect on the outside of the inner tube of the thermosiphon pump, the outer side of the inner tube is treated with a porous surface. The porous surface is processed by chip-free machining technology. The structure of the porous tube can increase the heat transfer area on the one hand. , and make the fluid flow through the porous rough surface to generate various secondary flows. Another more important reason is that the boiling temperature can be reduced due to the capillary action of the porous surface.

In order to improve the heat utilization rate of the thermosiphon pump, the concentrated solution inlet pipe and the dilute solution outlet pipe are made into sleeve-type heat exchangers, so that the heat utilization rate of the entire thermosiphon pump is further improved.

The above-mentioned condenser is directly processed by machining high-finned tubes. Compared with the conventional light tube outer fins, on the one hand, the processing process is reduced, and at the same time, the fins and tubes directly processed on the light tube It is an integral non-contact thermal resistance, which improves the heat transfer effect and reduces the length of the tube required for the condenser.

The above-mentioned absorber adopts a strengthened absorption tube with a crescent three-dimensional convex body inside, which is formed by bending a tube with a certain inclination, and is installed between the liquid storage tank and the evaporator. The reinforced absorber tube is made of different seamless tubes through chip-free machining. The three-dimensional crescent bodies arranged inside the tube make complex secondary flows such as split flow, mixing, and boundary layer separation flow when the fluid flows through, which promotes the heat and mass transfer process; fins are used outside the tube to increase the heat transfer coefficient and heat transfer area , the entire absorber is processed by using this enhanced mass transfer tube; the length of the tube required for the entire absorber is about 40% less than that of a smooth tube.

The above-mentioned refrigerant gas outlet pipe is welded with a distillation pipe, and the other end of the distillation pipe is connected to the condenser.

In order to facilitate filling and vacuuming, the liquid storage tank is equipped with a vacuum filling valve, which is used for system leak detection, vacuuming, and filling of refrigeration media including diffusion gas. It arranges complex valve piping systems outside the equipment, Makes the equipment easy to seal and eliminates valves on the equipment piping.

The above-mentioned vacuum canned valve is composed of a valve base body, a valve stem, a sealing body, a spring, a spring adjusting bolt, and a sealing washer. The valve base body is a hollow pipe body with a baffle plate in the middle. The air hole, the valve stem is located in the valve base, and the contact part between the two is the outer peripheral surface of the sealing body, which acts as a mechanical seal; the sealing gasket is set on the valve stem and moves with the valve stem; the spring is located at the bottom of the sealing body, and the other end is connected to the spring Adjusting bolt connection, the adjusting bolt is used to adjust the tension of the spring, which can be adjusted according to the pressure of the filling system. After adjustment, the adjusting bolt and the valve base are welded and fixed to avoid the vibration of the adjusting bolt caused by various reasons during the operation of the system. And loose, thus affecting the sealing performance of the system. When the filling is completed, the spring tension pushes the valve stem up, and the sealing gasket also moves up to closely contact with the base of the valve, which plays a double sealing role. The valve base body is provided with a second group of air inlet holes at the position corresponding to the bottom of the sealing body. Threads are provided on the outer edge of the air charging port of the valve base body.

The processing of the valve is relatively simple. Firstly, select materials compatible with the system working medium and the container where the valve is installed, use casting to process the valve base, valve stem and spring bolt parent body, and then use various mechanical processing methods to make it To meet the precision requirements; it is also possible to directly use materials without casting, and obtain valve substrates, valve stems and spring bolts that meet the precision requirements through mechanical processing. After processing the above parts, put the sealing washer on the valve stem first, then push the valve stem upwards from the back of the valve base, then install the spring from the back of the valve base, then install the adjusting bolt and adjust After a certain tension is reached, it is welded to the valve substrate, and finally welded to the liquid storage tank.

All seamless pipes involved in the present invention may be steel pipes, copper pipes or aluminum pipes.

When the equipment is manufactured, first use seamless tubes of various sizes, and use the chip-free machining method according to the aforementioned requirements to process them into porous tubes, high-finned tubes and strengthened absorption tubes; then, use conventional The mechanical processing method processes the liquid storage tank, thermosiphon pump, absorber, condenser and evaporator; finally connects the various parts and pipe fittings processed previously by welding. After the processing of the whole equipment is completed, the pressure test and leak detection are carried out through the vacuum filling valve. After the pressure test and leak detection pass, the working medium can be filled. After the filling is completed, the equipment can be put into use.

Compared with prior art, the advantage of the present invention is:

1. The variable annular gap triple casing thermosyphon pump is used to solve the problems of complex processing, low heat utilization rate, and high riser height of the key components of the absorption and diffusion refrigeration, so that various low-grade heat energy can be used (solar energy, flue gas and other various waste heat) to provide technical support for the commercial and practical application of novel and environmentally friendly refrigeration methods for refrigeration;

2. The vacuum filling valve is used for vacuuming and filling of the equipment, which avoids the installation of other valves on the equipment pipeline, simplifies the processing of the equipment, improves the sealing performance of the system, eliminates possible leakage points, and facilitates secondary Secondary filling prolongs the service life of the equipment.

3. Strengthen the absorption tube to promote the process of heat and mass transfer; use fins outside the tube to increase the heat transfer coefficient and heat transfer area, so that the heat and mass transfer performance of the entire absorber is improved, so that the length of the tube required for the entire absorber Compared with the smooth tube, it can be reduced by about 40%, which provides conditions for reducing the volume of the equipment of the present invention and increasing the cooling capacity of the equipment per unit volume.

4. Directly process the condenser in the present invention with high-finned tubes to improve the heat transfer effect and reduce the length of the tubes required by the condenser.

5. Due to the adoption of a variety of enhanced heat transfer and mass transfer technologies, and the change of the structure of the thermosiphon pump, the use of an internal heating form reduces heat loss and improves the heat utilization of the entire equipment. Promotional applications provide the basis.

Instructions attached

Fig. 1 is a structural representation of the present invention;

Figure 2 is a cross-sectional view of the reinforced absorber;

Fig. 3 is the schematic diagram of the crescent three-dimensional convex body in the reinforced absorption tube;

Figure 4 is a cross-sectional view of the vacuum filling valve.

In the figure: 1-inner pipe; 2-separation pipe; 3-outer pipe; 4-dilute solution outlet pipe; 5-concentrated solution inlet pipe; 6-refrigerant gas outlet pipe; 7-dilute solution outlet connection; 8-heating Channel fin; 9-condenser; 10-small tube; 11-small tube; 12-evaporator; 13-small tube; 14-absorber; 15-pipeline; 16-liquid storage tank; 17-vacuum tank valve; 18- Heating fluid inlet; 19-heating fluid outlet; 20-valve substrate; 21-valve stem; 22-sealing body; 23-spring; 24-spring adjusting bolt; 25-sealing washer; ; 27 - the second set of inlet holes for filling gas.

Detailed ways

The pumpless absorption refrigerator of the present invention, in Fig. 1, comprises thermosiphon pump, condenser 9, evaporator 12, absorber 14, liquid storage tank 16, thermosiphon pump is connected condenser 9 through refrigerant gas outlet pipe 6 The inlet end and the outlet end of the condenser 9 are connected to the evaporator 12, and the outlet end of the condenser 9 is divided into two small tubes 10 and 11, the small tube 11 is connected to the front end of the evaporator 12, and the small tube 10 is connected to the gas outlet of the evaporator 12 and connected together to the inlet end of the liquid storage tank 16, the liquid storage tank 16 is provided with outlets on both sides, the first side outlet is connected to the inlet of the concentrated solution inlet pipe 5, and the second side outlet is connected to the inlet end of the absorber 14 to absorb A small pipe 13 enters the front end of the evaporator 12 at the outlet end of the device 14, and the side of the upper end of the absorber 14 is connected with the dilute solution outlet pipe 4, and the outlet ends of the concentrated solution inlet pipe 5 and the dilute solution outlet pipe 4 are respectively connected to a thermosiphon pump . The concentrated solution inlet pipe 5 and the dilute solution outlet pipe 4 are made into sleeve-and-tube heat exchangers. The condenser 9 is directly processed from high-finned tubes. The absorber 14 adopts a strengthened absorber tube, as shown in Figures 2 and 3, which has a crescent three-dimensional convex body and is made of an inclined elbow, and is installed between the liquid storage tank 16 and the evaporator 12. The refrigerant gas outlet pipe 6 is welded with a distillation tube, and the other end of the distillation tube is connected to the condenser 9 . The liquid storage tank 16 is provided with a vacuum filling valve 17 .

The thermosyphon pump is a variable annular gap triple casing type thermosyphon pump, as shown in Figure 4, it is composed of an inner pipe 1, a separating pipe 2 and an outer pipe 3, wherein the lower end of the separating pipe 2 is welded to the inner pipe 1, and the upper end is open. And the lower end is connected with the concentrated solution inlet pipe 5; the outer pipe 3 is welded to the outer side of the separation pipe 2, the upper end is connected with the refrigerant gas outlet pipe 6, and the lower end is connected with the dilute solution outlet pipe 4. The inner tube 1 is elliptical, with fins on the inner side and porous surface treatment on the outer side, and the thickness gradually becomes thicker from the center to the outside.

The vacuum canned valve 17 is composed of a valve base 20, a valve stem 21, a sealing body 22, a spring 23, a spring adjusting bolt 24, and a sealing washer 25. The valve base 20 is a hollow pipe body with a baffle in the middle. There is a first group of air inlet holes 26 on the top, the valve stem is located in the valve base 20, the contact part between the two is the outer peripheral surface of the sealing body 22, the sealing gasket 25 is set on the valve stem, the spring 23 is located at the bottom of the sealing body 22, and the other end Connected with the spring adjusting bolt 24 , the valve base 20 is provided with a second group of air inlet holes 27 at a position corresponding to the bottom of the sealing body 22 . Threads are provided on the outer edge of the inflation port of the valve base 20 .

When the system needs to be filled with gas or liquid, use a pipe with internal thread to put the external thread on the valve base 20, and rotate a certain number of turns to make the valve stem 21 move downward, ensuring that the second group of air inlet holes 27 Still being sealed by the sealing body 22, and when the set pipe and the valve base 20 reach a sufficient degree of sealing, the gas in the outer pipe is pumped out, and the valve installed at the other end of the pipe is closed, then, continue to rotate the outer pipe, so that The sealing body 22 is constantly descending, and when the second air inlet 27 is fully opened, the filling liquid or gas tank can be connected at the other end of the pipeline, and the connection valve is opened to start filling. After the filling is finished, first close the connection valve, remove the auxiliary pipeline and all other connections, then unscrew the auxiliary pipeline from the valve base 20, and during the rotation process, the sealing body 22 will firstly close the second group of air inlets. 27 is closed and sealed, and finally the first group of air intake holes 26 is closed and sealed, and the system canning is completed.

When the device of the present invention is working, the heating heat source is first started, and the hot fluid enters from the heating fluid inlet 18 at the lower end of the thermosiphon pump, and flows out from the heating fluid outlet 19 at the upper end, and the hot fluid transfers heat to the inner pipe 1 and the partition through the inner wall of the inner pipe 1. The concentrated solution in the annular lifting channel between the tubes 2, the concentrated solution is heated in this annular channel, the volatile components in the concentrated solution evaporate, resulting in boiling, and at the same time drive the concentrated solution to lift upwards, during the continuous lifting process, the solution The concentration of the liquid is continuously decreasing, the gas-liquid is continuously separated, and heat is continuously obtained from the medium-heat fluid. When the lifting height exceeds the height of the separation pipe 2, the dilute solution will fall into the annular channel between the separation pipe 2 and the outer pipe 3 , this channel is the descending channel of the dilute solution, under the action of gravity and pressure difference, the dilute solution further separates the gas and liquid while descending; the gas generated in the ascending channel and the descending channel of the dilute solution passes through the gas outlet pipe 6, which also plays a role in fact. The distillation tube works and enters the condenser 9, and the refrigerant gas is condensed into a liquid in the condensed gas. There are two small tubes at the end of the condenser, one 10 goes straight down, the other 11 goes up first, and then bends down. The refrigerant that has been condensed into a liquid is contained in the small tube 10 that is directly downward. After the small tube descends a distance from one end, it turns horizontally and enters the front end of the evaporator 12; Inside the tube are uncondensed refrigerant gas and non-condensable diffusion gas (usually hydrogen or helium, non-condensable refers to the pressure and temperature in the absorption refrigeration process, rather than absolutely non-condensable), the small tube 11 is connected to the outlet of the mixed gas (containing refrigerant gas and diffusion gas) from the evaporator 12, and then continues downward through the pipeline 15, and enters the solution storage tank 16 under the action of the pressure difference; except for the condensed liquid entering the front end of the evaporator 12 Outside, a small pipe 13 enters the evaporator 12 at its rear end, and is parallel to the structure of the evaporator 12 until the front end. The small pipe 13 comes from the outlet of the absorber 14, mainly the unabsorbed diffusion gas. In this way, due to the partial pressure of the diffusion gas at the front end of the evaporator 12, although the total pressure of the condenser 9 is substantially equal to that of the evaporator 12, the condensed refrigerant is continuously evaporated to achieve the purpose of refrigeration. The mixed gas that enters the liquid storage tank 16 through the small pipe 13 enters the lower end of the absorber 14 and goes up along the absorber pipe all the way, while the side of the upper end of the absorber 14 is connected by the dilute solution outlet pipe 7 from the thermosiphon pump. The solution flows all the way down along the pipeline of the absorber 14 , and the two come into contact with each other in counter-phase flow, the refrigerant gas is basically absorbed, and the dilute solution becomes a concentrated solution, which enters the liquid storage tank 16 . The refrigerant gas in the mixed gas is basically absorbed, and the remaining diffused gas enters the evaporator 12 through the small tube 13, so that the diffused gas completes a cycle. The concentrated solution on the liquid storage tank 16, under the action of gravity and pressure difference, passes through the concentrated solution inlet pipe 5, and enters the concentrated solution in the annular lifting channel between the inner pipe 1 and the dividing pipe 2, where it is heated and boiled to evaporate, and it is also completed. A cycle is formed, and the entire refrigeration process is a continuous cycle process.

Claims (9)

1. A pumpless absorption refrigerator, comprising a thermosiphon pump, a condenser (9), an evaporator (12), an absorber (14), a liquid storage tank (16), and the thermosiphon pump passes through the refrigerant gas outlet pipe ( 6) Connect the inlet end of the condenser (9), the outlet end of the condenser (9) is connected to the evaporator (12), and it is characterized in that the outlet end of the condenser (9) is divided into two small pipes (10, 11), wherein A small tube (10) is connected to the front end of the evaporator (12), and another small tube (11) is connected to the gas outlet of the evaporator (12) and is connected to the inlet port of the liquid storage tank (16) together. Liquid tank (16) is provided with two sides outlets, and the first side outlet links to each other with the inlet of concentrated solution inlet pipe (5), and the second side outlet links to each other with absorber (14) inlet end, and the outlet end of absorber (14) also links to each other. There is a small pipe (13), which enters into the front end of the evaporator (12), the side of the upper end of the absorber (14) is connected with the dilute solution outlet pipe (4), the concentrated solution inlet pipe (5) and the dilute solution outlet pipe (4) The outlet ends of the outlets are respectively connected to the thermosiphon pump; the thermosiphon pump is a variable annular gap triple casing type thermosiphon pump, which is composed of an inner pipe (1), a separating pipe (2) and an outer pipe (3), wherein the separating The lower end of the pipe (2) is welded to the inner pipe (1), the upper end is open, and the lower end is connected to the concentrated solution inlet pipe (5); the outer pipe (3) is welded to the outer side of the separating pipe (2), and the upper end is connected to the refrigerant gas outlet Pipe (6), the lower end connects dilute solution outlet pipe (4). 2. A pumpless absorption refrigerator according to claim 1, characterized in that the inner tube (1) of the variable-annulus triple casing thermosiphon pump is oval, with fins on the inside and fins on the outside. With porous surface treatment, the thickness gradually becomes thicker from the center to the outside. 3. A pumpless absorption refrigerator according to claim 1, characterized in that the concentrated solution inlet pipe (5) and the dilute solution outlet pipe (4) are made of sleeve-and-tube heat exchangers. 4. A pumpless absorption refrigerator according to claim 1, characterized in that the condenser (9) is directly processed from high-finned tubes. 5. A pumpless absorption refrigerator according to claim 1, characterized in that the absorber (14) adopts a strengthened absorption tube with a crescent three-dimensional convex body inside and an inclined bent tube, and is installed in the liquid storage tank (16) and evaporator (12). 6. A pumpless absorption refrigerator according to claim 1, characterized in that said refrigerant gas outlet pipe (6) is welded with a distillation pipe, and the other end of the distillation pipe is connected to a condenser (9). 7. A pumpless absorption refrigerator according to claim 1, characterized in that said liquid storage tank (16) is provided with a vacuum filling valve (17). 8. A pumpless absorption refrigerator according to claim 7, characterized in that the vacuum canned valve (17) is composed of a valve base, a valve stem, a sealing body, a spring, a spring adjusting bolt, and a sealing washer. The base of the valve is a hollow pipe with a baffle in the middle. The baffle is provided with a first group of air inlet holes. The valve stem is located in the valve base. The contact part between the two is the outer peripheral surface of the sealing body. Above, the spring is located at the bottom of the sealing body, and the other end is connected with the spring adjusting bolt, and the valve base is provided with a second group of air inlet holes at the position corresponding to the bottom of the sealing body. 9. A pumpless absorption refrigerator according to claim 8, characterized in that the outer edge of the charging port of the valve base is provided with threads.

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