CN205425533U - Absorbed refrigeration unit does not have circulating pump refrigerant evaporimeter - Google Patents

Abstract

An absorption refrigeration unit without a circulation pump refrigerant evaporator and an absorption refrigeration unit and a refrigeration matrix using the non-circulation pump refrigerant evaporator. The non-circulation pump refrigerant evaporator includes: several rows of diversion grooves arranged in upper and lower layers; Heat exchange tubes are laid above the diversion tanks of each layer; refrigerant water flows outside the heat exchange tubes, and cold water circulates inside the heat exchange tubes; a number of discharge holes are provided on the side walls of the diversion tanks so that the refrigerant The water flows to the diversion groove in the lower layer to keep the refrigerant liquid submerged in the heat exchange tubes. The non-circulating pump refrigerant evaporator of the utility model adopts heat exchange tubes with small diameter, thin tube wall and high density to obtain a larger heat exchange area per unit volume to meet the requirements of small volume and high heat exchange efficiency; A diversion groove is set under each row of heat exchange tubes, so that the refrigerant water contacts the heat exchange tubes in the diversion groove for heat exchange, so that the refrigerant water flowing in the shell side does not need to fill the entire space of the shell side, and only needs to Just submerge the heat exchange tube.

Description

Absorption refrigeration unit without circulating pump refrigerant evaporator

technical field

The utility model relates to the production field of lithium bromide absorption refrigerators, in particular to a small absorption refrigerator which can be used as an independent unit of a refrigeration matrix and a refrigerant evaporator without a circulation pump inside.

Background technique

Absorption chillers have the advantages of energy saving and environmental protection, and are easy to use new energy sources such as solar energy and industrial waste heat, and have been continuously developed. Miniaturization and familyization will be another trend after it is put into industrial application fields.

The lithium bromide absorption refrigerator uses pure water as the refrigerant, that is, it relies on pure water to evaporate and absorb heat in a high vacuum environment to realize the refrigeration function. After absorbing heat and evaporating, the refrigerant vapor is absorbed by the lithium bromide solution, transported, heated and regenerated, condensed, and after returning to liquid state, it absorbs heat and evaporates again, and the refrigeration cycle is continuously carried out.

In the aforementioned process, the device that realizes evaporation and heat absorption is called an evaporator. Limited by the physical and chemical properties of pure water, for various refrigeration applications that meet the needs of human comfort, the evaporation temperature of the evaporator is usually set at about 5°C, which requires that the saturation pressure in the working chamber of the evaporator must be maintained at 872Pa about. This kind of pressure has high requirements on the airtightness of the refrigerator. In order to ensure the high vacuum sealing performance of the traditional absorption refrigerator, most of the shells must be made of thick steel plates or castings, and the heat exchange tubes are made of copper tubes. Shell-and-tube heat exchange structure. Refrigerators are large in size, heavy in weight, and have relatively poor corrosion resistance.

In addition, if a shell-and-tube heat exchanger is used to form a refrigerant evaporator without a circulation pump, the refrigerant generally flows on the shell side; since the absolute evaporation of the refrigerant is relatively small, if the circulation of the refrigerant water supplied by the shell side is equal to or only slightly more than Due to the evaporation of the refrigerant, with the evaporation of the refrigerant, the refrigerant fluid is continuously reduced, so that the heat exchange tube cannot be fully wetted, resulting in "dry spots" on the surface of the heat exchange tube. The appearance of dry spots greatly reduces the heat transfer coefficient of the heat exchanger. Therefore, in order to ensure sufficient humidification, it is often necessary to configure a special refrigerant pump on the shell side, using refrigerant water that is far more than the actual evaporation capacity, and under the pumping of the refrigerant pump, the non-evaporated refrigerant water is continuously pumped from the bottom of the evaporator. Spray onto the top of the evaporator. The existence of the refrigerant pump increases the volume weight and cost of the refrigerator on the one hand, and increases the operating cost on the other hand. Therefore, there is an urgent need to improve the structure of the evaporator to meet the requirements of lighter, more efficient, more energy-saving and environment-friendly.

Contents of the invention

In order to solve the above technical problems, one of the purposes of the utility model is to provide a non-circulation pump refrigerant evaporator for an absorption refrigeration unit. The so-called absorption refrigeration unit refers to a small lithium bromide absorption refrigerator with complete refrigeration function, which can be used alone or has the ability to be combined and expanded into a large-scale refrigeration matrix.

The specific technical scheme is as follows:

An absorption refrigerating unit without a circulating pump refrigerant evaporator, comprising:

Several rows of diversion grooves arranged in upper and lower layers;

Heat exchange tubes are laid above the diversion grooves of each layer;

Refrigerant water flows outside the heat exchange tubes, and cold water circulates inside the heat exchange tubes;

A number of discharge holes are provided on the side wall of the flow diversion tank, so that the refrigerant water flows to the lower layer of the diversion groove to keep the refrigerant liquid submerged in the heat exchange tubes.

Further, the diversion groove is a rectangular shallow groove;

The side wall of the flow diversion groove facing one side of the absorber is a slope type liquid separator, which is used to intercept refrigerant water and only allow refrigerant vapor to pass through.

Further, the upper and lower sides of the diversion tank are provided with support bars forming a certain angle with the edge of the diversion tank, and the support bars are used to support the upper and lower pipelines and change the flow of refrigerant water in the diversion tank direction, resulting in turbulent flow.

Further, the included angle between the support bar and the edge of the diversion groove is 45° to 135°.

Further, the discharge hole is in the shape of an inverted triangle on the sloped liquid barrier of the diversion groove.

Further, the discharge holes on two adjacent layers of diversion grooves are vertically staggered.

Further, the diversion groove makes the flow path of the refrigerant liquid form a "zigzag" shape, which is used to prolong the heat exchange time between the refrigerant liquid and the heat exchange tube and generate turbulent flow.

Further, the diversion groove is made of engineering plastics; the heat exchange tube is made of stainless steel.

Further, due to the combined effect of the discharge hole and the diversion groove, after entering a stable working condition, the refrigerant water accumulated in the diversion groove just submerges the heat exchange tube;

The refrigerant water circulated from the regenerator and condenser is supplemented to the first row of diversion grooves of the evaporator, and the sum of the evaporation of refrigerant water in each row of diversion grooves is exactly equal to the supplementary amount of refrigerant water, so the evaporator does not need to be used Refrigerant circulation pump.

The second purpose of the present utility model is to provide an absorption refrigeration unit, which includes the above-mentioned absorption refrigeration unit without a circulating pump refrigerant evaporator.

The third purpose of the utility model is to provide an absorption refrigeration matrix, including a plurality of absorption refrigeration units;

The absorption refrigeration unit includes the above-mentioned absorption refrigeration unit without a circulation pump refrigerant evaporator.

The beneficial effects of the utility model are:

The non-circulating pump refrigerant evaporator of the utility model adopts heat exchange tubes with small diameter, thin tube wall and high density to obtain a larger heat exchange area per unit volume to meet the requirements of small volume and high heat exchange efficiency; A diversion groove is set under each row of heat exchange tubes, so that the refrigerant water contacts the heat exchange tubes in the diversion groove for heat exchange, so that the refrigerant water flowing in the shell side does not need to fill the entire space of the shell side, and only needs to Just submerge the heat exchange tubes, thereby reducing the amount of refrigerant water used; there is a V-shaped (inverted triangle) discharge hole on the liquid separation wall of the diversion tank, which can automatically adjust the refrigerant flow in the diversion tank according to the size of the refrigerant flow. The deposition height inside makes the refrigerant water evenly infiltrate the heat exchange tube when the cooling load is small and the refrigerant flow rate is small, thereby reducing the chance of "dry spots" on the surface of the heat exchange tube and improving the evaporation heat transfer coefficient; at the same time, The utility model also adopts new materials and new technology: the evaporator abandons expensive metal materials and replaces them with engineering plastics with stronger anti-corrosion performance and easier molding; the heat exchange tube abandons expensive brass materials and replaces them with more corrosion-resistant stainless steel material.

Description of drawings

Fig. 1 is a three-dimensional structure schematic diagram of the assembly of the non-circulating pump refrigerant evaporator of the present invention;

Fig. 2A is a cross-sectional view of the refrigerant evaporator without a circulation pump of the present invention;

Figure 2B is a partially enlarged view of the circular area in Figure 2A;

Fig. 3 is a structural schematic diagram of the diversion groove of the refrigerant evaporator without a circulation pump of the present invention.

Among them, some structures or components in the figure are marked as follows:

Evaporator 101;

Absorber 102;

Concentrated solution supply hole 103

Refrigerant water discharge hole 104;

Condenser bottom partition 201

Orifice 202;

Evaporator heat exchange tube 203;

diversion groove 204;

Absorber heat exchange tube 205;

Solution dispenser 206;

Regenerator bottom partition 207

Absorber solution outlet 208;

Evaporator refrigerant water return port 209;

Slope type liquid baffle 210;

The first row of diversion grooves 301 of the evaporator;

Inverted triangular discharge hole 302;

Slope type liquid baffle 303;

support bar 304;

Heat exchange tube 305;

O-ring 306;

Absorber flow channel 307 .

detailed description

The accompanying drawings constitute a part of this specification; various specific embodiments of the present utility model will be described below with reference to the accompanying drawings. It should be understood that, for the convenience of description, the present invention uses terms indicating directions, such as "front", "rear", "upper", "lower", "left", "right" etc. to describe the present invention. Various example structural parts and elements, but these directional terms are determined only in accordance with the example orientations shown in the drawings. Since the disclosed embodiments of the present invention can be arranged in different orientations, these directional terms are for illustration only and should not be regarded as limiting. Where possible, the same or similar reference numerals used in the present invention refer to the same components.

Fig. 1 is a three-dimensional structure schematic diagram of the assembly of the non-circulating pump refrigerant evaporator of the present invention;

As shown in Figure 1, the evaporator 101 and the absorber 102 are arranged in the same cavity; the refrigerant water required by the evaporator 101 is supplied by the refrigerant water orifice 104 at the bottom of the condenser above it, and the absorber 102 The required concentrated solution is supplied from the concentrated solution supply hole 103 provided at the bottom of the regenerator above it.

Fig. 2A is a sectional view of the refrigerant evaporator without a circulation pump of the present invention, and Fig. 2B is a partial enlarged view of the circular area in Fig. 2A.

As shown in FIG. 2A and FIG. 2B , the heat exchange tube of the present invention adopts a compact layout, and adopts heat exchange tubes with small diameter, thin tube wall and high density. As an example, the evaporator 101 is composed of heat exchange tubes 203 with a nominal outer diameter of 3 mm, which are symmetrically and evenly arranged into a tube bundle array with 15 tubes in each row and 36 tubes in each column; The center-to-center distance is 3.5-4.5mm; in the vertical direction, the center-to-center distance between two adjacent heat exchange tubes is 6.5-7.5mm; the fluid flowing inside the tube is cold water; the fluid flowing outside the tube is refrigerant water. Such a design makes the evaporator 101 of the present invention actually a compact shell-and-tube heat exchange structure with a large ratio of heat transfer area to volume.

In the evaporator 101 , two adjacent rows of heat exchange tubes 203 are separated by a diversion groove 204 . In the 36 rows of heat exchange tube bundles, there are 36 guide slots in total. Two adjacent guide grooves 204 and the surrounding heat exchange tubes 203 constitute a shell-and-tube heat exchanger; therefore, the evaporator 101 is actually formed by connecting 36 shell-and-tube heat exchangers. Each diversion groove 204 is manufactured by precision injection molding, and the contact surface between the diversion groove 204 and the heat exchange tube 203 is sealed with an O-ring 306 (see FIG. 3 ) to ensure airtightness and watertightness.

In the initial state, the refrigerant water accumulates on the bottom baffle 201 of the condenser; the refrigerant water flows into the internal guide groove 204 of the evaporator 101 (see FIG. 1 ) after throttling and reducing pressure through the orifice 202 on the bottom baffle 201 In the first row of diversion grooves. By rationally designing the drain hole 302 on the diversion groove 204 (see FIG. 3 ), the refrigerant water accumulates in the first row of diversion groove 204 to just submerge the first row of heat exchange tubes in the heat exchange tube bundle 203; Under the action of the flow holes 302 , the refrigerant water flows through the subsequent rows of flow-guiding grooves in the flow-guiding grooves 204 in sequence.

In each row of diversion grooves, the refrigerant water exchanges heat with the cold water flowing in the tube side of the heat exchange tube 203, part of the refrigerant water absorbs heat and evaporates to become refrigerant vapor, and at the same time, the temperature of the cold water in the tube side of the heat exchange tube 203 decreases; The refrigerant water that has not evaporated in the diversion tank 204 returns to the absorber through the return hole 209 at the bottom of the evaporator 101 under the action of gravity. The refrigerant vapor evaporated in the diversion groove of the evaporator flows to the absorber 205 through the slope type liquid separator 210 , and is absorbed by the solution distributed from the solution distributor 206 in the evaporator 205 .

The entire process of the refrigerant water from the orifice 202 to the evaporator 205 and back to the absorber from the return hole 209 is all completed by gravity. In addition, the refrigerant water in the 36 diversion grooves performs immersion heat exchange with the heat exchange tubes. When working in a steady state under rated cooling conditions, the refrigerant water supplied from the orifice 202 passes through the first row of diversion grooves and reaches the last row. When the diversion tank is used, it is just completely evaporated, so there is no need to use a circulation pump.

Fig. 3 is a structural schematic diagram of the diversion groove of the refrigerant evaporator without a circulation pump of the present invention;

FIG. 3 shows the first three rows of guide grooves in the guide groove set 204 in FIG. 2 . The first row of flow guide grooves 301 is a rectangular flow guide groove located below the heat exchange tube bundle 305 . Both sides of the bottom of the diversion groove 301 are provided with support bars 304 forming an angle of 45° to 135° with the edge of the diversion groove 301 . The support bars 304 are used to support the heat exchange tubes 305 , and at the same time, the support bars also change the flow direction of the refrigerant water flowing in the diversion groove 301 and generate turbulent flow. The support bar 304 is not only the support of the heat exchange tubes 305, but also the diversion device of the refrigerant water, which not only plays the role of transmitting vacuum pressure, but also guides the refrigerant water to flow through the heat exchange tubes 305 along the meandering path, increasing the flow distance of the refrigerant water, Creates a turbulent flow effect.

A slope-type liquid separator 303 is provided on the left edge of the diversion groove 301 for intercepting liquid droplets that may be entrained in the refrigerant vapor. Four discharge holes 302 are provided on the side slope of the liquid separator 303 facing the diversion groove 301 for evenly distributing the refrigerant water in the diversion groove 301 to the lower diversion groove. The diversion groove 301 is used to divert and distribute the refrigerant water accumulation, so that the refrigerant water flows evenly through each row of heat exchange tubes, which not only effectively prevents the free fall of the refrigerant water to form splashes, but also prevents the refrigerant water from top to bottom When flowing through each row of heat exchange tubes 305 layer by layer, the heat of the cold water flowing inside the heat exchange tubes 305 can be better absorbed.

The discharge hole 302 is an inverted triangle, and the discharge hole 302 can automatically adjust the deposition height of the refrigerant water in the diversion groove 301 according to the flow rate of the refrigerant: when the flow rate of the refrigerant water is large, the liquid height will reach the upper part of the discharge hole 302 , the liquid discharge volume increases; when the refrigerant water flow rate is small, its liquid level is low, and its liquid discharge volume also decreases through the lower part of the discharge hole 302 . This enables the refrigerant water to evenly infiltrate the heat exchange tubes 305 when the cooling load is small and the refrigerant flow rate is small, reducing the chance of "dry spots" on the surface of the heat exchange tubes 305 and improving the heat transfer coefficient.

In all the diversion grooves after the first row of diversion grooves 301, the same discharge holes 302 are all provided, but the positions of each layer are staggered, and the method is as follows: the discharge holes of the upper layer are connected with the adjacent lower layers. The discharge holes cannot be straight through. The refrigerant water from the discharge holes of the upper layer cannot directly drip to the discharge holes of the next layer, but first drips to the slope-type liquid baffle 303, and then flows between the liquid baffle 303 and the support bar 304. Flow through the heat exchange tube bundle 305 in the diversion groove 301 under the combined action; after exchanging heat with the fluid in the tube side of the heat exchange tube bundle 305 , then pass through 302 and drop to the next layer. Such a design makes the flow path of the refrigerant water form a "zigzag" shape, and the contact heat exchange time between the refrigerant water and the surface of the heat exchange tube is greatly increased; the flow path of the refrigerant water is interrupted many times, which increases the flow turbulence effect and improves the heat transfer efficiency.

Although the utility model will be described with reference to the specific embodiments shown in the accompanying drawings, it should be understood that, without departing from the spirit, scope and background of the utility model teaching, the utility model of the non-circulating pump refrigerant evaporator and absorption refrigeration There are many variations of the unit and cooling matrix, such as changing the shape of the flow guide slots, changing the size of the drain holes, and so on. Those skilled in the art will also realize that there are different ways to change the parameters and dimensions in the disclosed embodiments of the utility model, but these all fall within the spirit and scope of the utility model and claims.

Claims (11)

1. an absorption refrigeration unit is without circulating pump refrigerant evaporator, it is characterised in that including:

Some rows are the guiding gutter of levels arrangement；

Heat exchanger tube is laid above each layer guiding gutter；

Chilled water is in described heat exchanger tube flows outside, and cold water is at described heat exchanger tube internal circulation；

Described guiding gutter sidewall is provided with some discharge orifices, makes chilled water flow to lower floor's guiding gutter, to keep cooling medium liquid submergence heat exchanger tube.

2. absorption refrigeration unit as claimed in claim 1 is without circulating pump refrigerant evaporator, it is characterised in that:

Described guiding gutter is rectangular shallow slot；

Described guiding gutter is ramp type liquid islocation plate towards the sidewall of side absorber, is used for retaining chilled water, only allows refrigerant vapor to pass through.

3. absorption refrigeration unit as claimed in claim 1 is without circulating pump refrigerant evaporator, it is characterised in that:

The upper and lower surface of described guiding gutter, is provided with the support bar in a certain angle with described guiding gutter edge, and described support bar is used for supporting upper and lower pipeline, and changes the flow direction of chilled water in guiding gutter, produces turbulent flow.

4. absorption refrigeration unit as claimed in claim 3 is without circulating pump refrigerant evaporator, it is characterised in that:

Described support bar is 45 ° to 135 ° with the angle at guiding gutter edge.

5. absorption refrigeration unit as claimed in claim 1 is without circulating pump refrigerant evaporator, it is characterised in that:

Described discharge orifice is on the ramp type liquid islocation plate of described guiding gutter, in del.

6. absorption refrigeration unit as claimed in claim 5 is without circulating pump refrigerant evaporator, it is characterised in that:

Discharge orifice in the vertical direction on adjacent two layers guiding gutter mutually staggers.

7. absorption refrigeration unit as claimed in claim 1 is without circulating pump refrigerant evaporator, it is characterised in that:

Described guiding gutter makes the flow path of cooling medium liquid constitute " it " font, for extending the heat exchanger time of cooling medium liquid and heat exchanger tube and producing turbulent flow.

8. absorption refrigeration unit as claimed in claim 1 is without circulating pump refrigerant evaporator, it is characterised in that:

Described guiding gutter is made up of engineering plastics；Heat exchanger tube uses stainless steel material to make.

9. absorption refrigeration unit as claimed in claim 8 is without circulating pump refrigerant evaporator, it is characterised in that:

Described discharge orifice and the synergy of guiding gutter, after entering steady working condition, the chilled water lucky submergence heat exchanger tube of described guiding gutter accumulation；

The chilled water come from regenerator and condenser circulation adds the first row's guiding gutter adding to vaporizer, and respectively arranges the chilled water evaporation capacity sum in guiding gutter and be exactly equal to the magnitude of recruitment of chilled water, and vaporizer is required for refrigerant circulation pump.

10. an absorption refrigeration unit, it is characterised in that:

Including the absorption refrigeration unit described in any one of claim 1-9 without circulating pump refrigerant evaporator.

11. 1 kinds of absorption refrigeration matrixes, it is characterised in that:

Including multiple absorption refrigeration unit；

Described absorption refrigeration unit includes that the absorption refrigeration unit described in any one of claim 1-9 is without circulating pump refrigerant evaporator.