CN219510834U - Flue gas absorption type cold water/heat pump unit of heat pipe type generator - Google Patents

Abstract

A smoke absorption cold water/heat pump unit of a heat pipe type generator comprises the heat pipe type generator; the generator comprises a shell, wherein the inner cavity of the shell is divided into a solution cavity and a smoke cavity which are arranged up and down; the inner cavity of the shell is also provided with a plurality of gravity type heat pipes, each gravity type heat pipe comprises a condensation section and an evaporation section, the evaporation section is positioned in the smoke cavity, the condensation section is positioned in the solution cavity, and the length of the evaporation section is larger than that of the condensation section. The utility model can utilize heat pipe medium without mass transfer power, and the cold and hot ends have almost no temperature difference and have high-intensity heat transfer capability; the flue gas is directly used as a heat source of the cold water and heat pump unit, so that the waste heat grade is not reduced due to secondary heat exchange, and the refrigerating and heating grade and the waste heat utilization efficiency are better.

Description

Flue gas absorption type cold water/heat pump unit of heat pipe type generator

Technical Field

The utility model relates to an absorption type cold water/heat pump unit utilizing low-temperature flue gas or similar waste heat, in particular to a flue gas absorption type cold water/heat pump unit of a heat pipe type generator.

Background

Waste heat resources in various industries in industrial production account for 17% -80% in fuel consumption, and are mostly discharged in the form of flue gas and the like. The high-temperature and medium-temperature flue gas waste heat resources have higher relative utilization rate. Low temperature flue gas generally refers to flue gas (or high temperature flue gas) at temperatures below 230 ℃ and also to flue gas at temperatures below 200 ℃ or below 150 ℃. The low-temperature flue gas waste heat resource is difficult to use for a long time due to the problems of low grade, high recovery difficulty, long recovery period, corrosion of the dew point of the flue gas and the like, and causes great waste. The waste heat utilization of low-temperature flue gas is beneficial to reducing the damage of the flue gas to the environment, improving the effective utilization rate of energy, saving energy and reducing emission, and is beneficial to realizing carbon peak and carbon neutralization.

Common smoke type absorption cold water and heat pump units, such as smoke type absorption first type heat pump units (hereinafter referred to as smoke type heat pump units) and smoke type absorption cold water units (hereinafter referred to as smoke type cold water units), can utilize low-temperature smoke (entering a generator as a driving heat source) to prepare medium-temperature hot water or cold water for process and life. The method is simple and direct to use the high-temperature and medium-temperature flue gas, but is difficult to use the low-temperature flue gas simply and economically. The reasons for this include:

(1) The flue gas often contains sulfur oxide, nitrogen oxide, hydrogen chloride and other acid gases and water vapor, when the temperature of the flue gas is reduced to the combined condensation of the acid gases and the water vapor, strong acid can be generated, the heat exchanger is severely corroded, the high-cost flue gas type heat pump unit/water chiller is damaged, and even the expensive lithium bromide solution is leaked or deteriorated.

(2) The low-temperature flue gas temperature is low, the temperature difference between the low-temperature flue gas temperature and the generator of the first-class heat pump unit/water chilling unit is small, the heat transfer coefficient of gas is very low, the number of heat exchange tubes of the generator is increased, the corresponding lithium bromide solution consumption is large, and the cost is greatly increased due to the fact that lithium salt is expensive.

In the prior art, a flue gas heat exchanger (or a flue gas boiler) is often adopted to prepare hot water, and then the hot water type absorption type first heat pump unit (hereinafter referred to as hot water type heat pump unit) or the hot water type absorption type cold water unit is used as a heat source, as shown in fig. 1 and 2. This is actually to change the flue gas type heat pump unit/water chiller unit into a waste heat boiler + hot water type heat pump unit/water chiller unit. The "other parts" of the hot water type heat pump unit/cold water unit in fig. 1 and 2 refer to the common structure of the absorption type first heat pump unit/cold water unit, wherein the unit comprises a condenser, an absorber, an evaporator, a heat exchanger, a pipeline, a pump group and the like, besides the generator.

On the one hand, although the corrosive flue gas is isolated from the absorption type first heat pump unit/water chiller, the secondary heat exchange further reduces the grade of waste heat, so that the heating capacity and the heating temperature are reduced, and the utilization efficiency of the waste heat is also reduced. On the other hand, the principle that the heat exchange coefficient of hot water is far higher than that of flue gas is utilized, the heat exchange tube consumption of a generator of a hot water type heat pump unit/cold water unit and the lithium bromide solution consumption are greatly reduced, but the cost of a heat exchanger or a flue gas hot water boiler is increased, and a water pump and a heat source water pipeline are also required to be added.

Disclosure of Invention

The utility model aims to overcome the defects of the prior art and provide a smoke absorption type cold water/heat pump unit of a heat pipe type generator, which has lower cost, higher heating grade and higher waste heat utilization efficiency.

The technical scheme of the utility model is as follows: a smoke absorption type cold water/heat pump unit of a heat pipe type generator comprises a generator; the generator comprises a shell, wherein the inner cavity of the shell is divided into a solution cavity and a smoke cavity which are arranged up and down; the inner cavity of the shell is also provided with a plurality of gravity type heat pipes, each gravity type heat pipe comprises a condensation section and an evaporation section, the evaporation section is positioned in the smoke cavity, the condensation section is positioned in the solution cavity, and the length of the evaporation section is larger than that of the condensation section.

The absorption type cold water/heat pump unit of the utility model can be an absorption type cold water unit for independently producing cold water or an absorption type heat pump unit for independently producing hot water, and also can be an absorption type cold water/heat pump unit with the functions of producing cold water and producing hot water. When the three forms do not need to embody the difference, the three forms are unified and simply called as absorption cold water and heat pump units.

Further, a liquid distribution device is arranged in the solution cavity and is used for uniformly distributing lithium bromide solution, and the liquid distribution device is positioned above the condensation section of the gravity type heat pipe.

Further, the solution cavity is positioned above the smoke cavity, the smoke cavity is provided with a smoke inlet and a smoke outlet, and the top of the smoke cavity is provided with a steam outlet; the solution cavity is provided with a dilute solution inlet and a concentrated solution outlet, and the bottom of the solution cavity is provided with a condensate outlet; the dilute solution inlet is communicated with the liquid distribution device.

Further, the length of the evaporation section of the gravity type heat pipe is 100-3000mm, and the length of the condensation section is 50-1000mm.

Further, the length of the evaporation section of the gravity type heat pipe is 500-1500mm, and the length of the condensation section is 100-500mm.

Further, the evaporation section is made of carbon steel, acid-resistant stainless steel, dew point corrosion-resistant low alloy steel or dew point corrosion-resistant stainless steel.

Further, the outer surface of the evaporation section is coated with a teflon coating, an enamel coating or a heat-resistant acid-resistant paint.

Further, the material of the condensing section is the same as that of the evaporating section, or the material of the condensing section is low carbon steel or low alloy steel.

Further, the surface of the evaporation section and/or the condensation section of the gravity type heat pipe is smooth and flat.

Further, the surface of the evaporation section and/or the condensation section of the gravity type heat pipe is provided with annular or spiral fins, vertical diversion grooves or diversion ribs, diagonal lines, tree-grain bulges or grooves, punctiform bulges or grooves, or a combination of the above.

The utility model has the beneficial effects that:

compared with a hot water type absorption cold water/heat pump unit which firstly prepares hot water through a waste heat boiler and then uses the hot water as a heat source: on one hand, a gravity type heat pipe is arranged in the generator, and a condensing section and an evaporating section are arranged on the gravity type heat pipe, so that mass transfer power is not needed by a heat pipe medium, the cold and hot ends of the gravity type heat pipe almost have no temperature difference, and the gravity type heat pipe has high-strength heat transfer capability; the flue gas is directly used as a heat source of the cold water/heat pump unit, compared with a mode of passing through a waste heat boiler or the waste heat boiler, the flue gas has no waste heat grade reduction caused by secondary heat exchange, and has better heating grade and waste heat utilization efficiency;

compared with a smoke type absorption cold water/heat pump unit directly utilizing smoke heating generator solution: although the flue gas and the lithium bromide solution are subjected to direct heat exchange through the heat exchange tube, the temperature difference problem does not exist, the convection heat exchange efficiency of the flue gas side is far lower than that of the solution side, the heat exchange area can only be determined according to the heat exchange efficiency of the flue gas side, namely, the heat exchange area of the solution side is huge, a lot of lithium bromide solution is needed for heat exchange, and the cost is high. According to the heat pipe, the length of the evaporation section is longer than that of the condensation section, and the outer wall of the evaporation section of the heat pipe is low-efficiency smoke convection heat exchange, so that more heat exchange area is needed; the outer wall of the condensing section of the heat pipe is subjected to liquid phase change heat exchange, so that less heat exchange area and less solution are needed, and the cost is greatly reduced; on the other hand, through setting up the cloth liquid device, can evenly spray the solution in the condensation segment of each gravity type heat pipe, fully contact with the condensation segment, improve heat exchange efficiency, belong to falling film boiling, do not have the problem that the liquid level pressure of solution soaking type heat transfer device influences boiling.

The problem of low-temperature flue gas utilization is that the dew point of the flue gas corrodes, and sulfur oxides in the flue gas are combined with water vapor to form sulfuric acid in the cooling process, so that the heat exchange tube is severely corroded. In particular, the direct heat exchange method of flue gas and lithium bromide solution through a heat exchange tube can cause the flue gas to pollute the solution or cause leakage loss of the solution once corrosion occurs. The device not only adopts dew point corrosion resistant materials, but also the smoke and the solution are subjected to secondary heat exchange through the heat pipe, and even if the smoke side is corroded, the heat pipe is only affected, and expensive lithium bromide solution pollution or leakage cannot be caused.

Drawings

FIG. 1 is a schematic diagram of a connection structure of a hot water type heat pump unit of the prior art;

FIG. 2 is a schematic diagram of a connection structure of a hot water chiller of the prior art;

FIG. 3 is a schematic diagram of a heat pipe cold water/heat pump unit according to an embodiment of the present utility model;

FIG. 4 is a schematic diagram of the internal structure of a gravity-fed heat pipe of the heat pipe cold water/heat pump unit generator of the embodiment shown in FIG. 3.

Detailed Description

The utility model will be described in further detail with reference to the drawings and the specific examples.

As shown in fig. 3 and 4: the smoke absorption type cold water/heat pump unit of the heat pipe type generator can be a heat pump unit or a cold water unit, and is hereinafter called as a heat pipe cold water/heat pump unit, and comprises a generator; the generator comprises a shell, wherein the inner cavity of the shell is divided into a solution cavity and a smoke cavity which are arranged up and down; the inner cavity of the shell is also provided with a plurality of gravity type heat pipes, each gravity type heat pipe comprises a condensation section and an evaporation section, the evaporation section is positioned in the smoke cavity, the condensation section is positioned in the solution cavity, and the length of the evaporation section is larger than that of the condensation section.

In this embodiment, the heat pipe cold water/heat pump unit is an absorption cold water unit and a first type heat pump unit which directly adopt low-temperature flue gas as a driving heat source to prepare cold water and/or hot water for process or life, and the heat pipe and the low-temperature flue gas are adopted in the generator to exchange heat. The advantages are that: the heat pipe medium is utilized without mass transfer power, the cold and hot ends of the heat pipe medium have almost no temperature difference, and the heat pipe medium has high-strength heat transfer capability; the flue gas is directly used as a heat source of the heat pipe heat pump unit, so that the waste heat grade is not reduced due to secondary heat exchange, and the flue gas has better heating grade (higher medium-temperature water temperature) and waste heat utilization efficiency (lower low-temperature water temperature). The heat pipe is internally provided with high-efficiency phase-change mass transfer and heat transfer, and a heat transfer short plate of the whole device is used for heat exchange between the evaporation section of the heat pipe and smoke, or heat exchange between the condensation section of the heat pipe and solution, namely low-efficiency smoke convection heat exchange on the outer wall of the evaporation section of the heat pipe, so that more heat exchange area is needed, and the length of the evaporation section is longer; the outer wall of the condensing section of the heat pipe is liquid phase-change heat exchange, so that the heat exchange efficiency is high, less heat exchange area and less solution are needed, and the cost is greatly reduced. Therefore, the length of the evaporating section of the heat pipe is longer than that of the condensing section.

In this embodiment, the gravity assisted heat pipe transfers heat from bottom to top without requiring a complex die. The gravity type heat pipes are arranged side by side at intervals to form a heat pipe assembly, and a liquid distribution device is arranged above the heat pipe assembly so as to uniformly distribute lithium bromide solution. The shell is provided with a flue gas inlet and a flue gas outlet, the bottom of the shell is provided with a condensate outlet, and the upper part of the shell is provided with a dilute solution inlet and a concentrated solution outlet; the top end of the shell is provided with a water vapor outlet. Wherein the flue gas inlet and the flue gas outlet are arranged below the dilute solution inlet and the concentrated solution outlet. The liquid distribution device comprises a plurality of nozzles which are uniformly distributed, the nozzles are communicated with a dilute solution inlet through a channel, the dilute solution is used for being connected into an absorber, and after entering the liquid distribution device, the dilute solution is sprayed out through the nozzles to exchange heat with a condensation section of the gravity type heat pipe. Because of the relationship and refrigeration principles of the generator and other components (i.e., evaporator, condenser, absorber) of the heat pipe chiller/heat pump unit, similar to the conventional absorption chiller/absorption first-type heat pump unit, the other components are not related to the technology of the present utility model and therefore are not described in further detail.

In this embodiment, the diameter of the gravity type heat pipe is 5-200mm, preferably 20-40mm; the gravity type heat pipe comprises an evaporation end and a condensation end, wherein the length of the evaporation section is 100-3000mm, preferably 500-1500mm; the length of the condensing section is 50-1000mm, preferably 100-500mm. According to the reasons, the length of the evaporating section of the heat pipe is longer than that of the condensing section, and the height of the whole heat pipe cold water/heat pump unit is slightly higher than that of the evaporating section of the heat pipe plus that of the condensing section. Considering the space height of transportation and installation, the height is generally not more than 4000mm (limited by bridges, tunnels and the like in the transportation process), preferably not more than 2500 (convenient for container transportation and limited by the layer height of a general building), the requirement for heat exchange area is met, the length and the width are increased when the height is reduced, and the occupied area is increased. Therefore, the height of the space is utilized as much as possible. The maximum length (namely the height of the unit) of the heat pipe can be selected in the field assembly, so that the occupied area is reduced.

In this embodiment, the evaporation section of the gravity type heat pipe is used for exchanging heat with the flue gas, and the surface of the evaporation section can be smooth and flat; however, for enhanced heat exchange, the outer surface is preferably designed to be of a non-flat structure, such as a structure with annular or spiral fins, or a structure with vertical flow guide grooves or flow guide ribs, or a structure with diagonal, tree-grain protrusions or grooves, or a structure with dot-like protrusions or recesses, or a combination of the above. The evaporation section is internally provided with a working medium, and the working medium can be aqueous solution added with corrosion inhibitor or organic matters suitable for working below 200 ℃.

In this embodiment, the condensation section of the gravity type heat pipe is used for exchanging heat with the solution, and the surface of the condensation section may be smooth and flat; however, in order to enhance heat exchange, the outer surface of the evaporator is preferably designed to be a non-flat structure, and the outer surface structure of the evaporator is specifically referred to and will not be described in detail herein.

In this embodiment, the evaporation section of the gravity type heat pipe is in contact with the flue gas, and according to different flue gas components (particularly corrosive components such as sulfur-containing oxide, etc.), the evaporation section can be made of carbon steel, acid-resistant stainless steel, dew point corrosion-resistant low alloy steel or dew point corrosion-resistant stainless steel, and teflon coating, enamel coating and heat-resistant acid-resistant paint can be adopted as the materials. Different gravity type heat pipes can use one or a combination of the above materials in the same generator.

In this embodiment, the condensation section of the gravity type heat pipe is in contact with the solution, and the material of the condensation section may be the same as the evaporation section of the heat pipe, or may be different materials, and in this embodiment, low carbon steel or low alloy steel is preferably used.

The working principle of the embodiment is as follows: the low-temperature flue gas enters from a flue gas inlet of the generator shell, exchanges heat with the evaporation sections of the gravity type heat pipes, releases heat and is discharged from a flue gas outlet; the working medium in the evaporation section absorbs the heat of the flue gas in the flue gas cavity and evaporates, the generated vapor flows upwards to the condensation section, the vapor is subjected to heat exchange with the solution in the condensation section, so that the vapor in the condensation section is condensed into a liquid working medium, the liquid working medium flows back to the evaporation section for cyclic utilization under the action of gravity, meanwhile, the vapor in the condensation section releases heat in the process of condensing into the liquid working medium, the thin solution sprayed outside is subjected to heat exchange through the pipe wall, so that the thin solution absorbs heat to generate refrigerant vapor and becomes a concentrated solution, the refrigerant vapor is output from a concentrated solution outlet when the refrigerant vapor is accumulated to a certain height (enters an absorber of an absorption cold water and heat pump unit through a heat exchanger), and the refrigerant vapor is discharged from a water vapor outlet (enters a condenser of the absorption cold water/heat pump unit). So reciprocating, realize the heat exchange between the solution to flue gas heat and absorption cold water, heat pump set.

In summary, according to the utility model, on one hand, the gravity type heat pipe is arranged in the generator, and the condensing section and the evaporating section are arranged on the gravity type heat pipe, so that mass transfer power is not needed by the heat pipe medium, the temperature difference is almost avoided at the cold and hot ends, and the heat pipe has high-strength heat transfer capability; the flue gas is directly used as a heat source of the heat pipe cold water/heat pump unit, so that the waste heat grade is not reduced due to secondary heat exchange, and the heating grade and the waste heat utilization efficiency are better; the flue gas and the lithium bromide solution directly exchange heat through the heat exchange tube, although the temperature difference problem does not exist, the convection heat exchange efficiency of the flue gas side is far lower than that of the solution side boiling phase change heat exchange, the heat exchange area can only be determined according to the heat exchange efficiency of the flue gas side, namely, the heat exchange area of the solution side is huge, a lot of lithium bromide solution is needed for heat exchange, and the cost is high. According to the heat pipe, the length of the evaporation section is longer than that of the condensation section, and the outer wall of the evaporation section of the heat pipe is low-efficiency smoke convection heat exchange, so that more heat exchange area is needed; the outer wall of the condensing section of the heat pipe is subjected to liquid phase change heat exchange, so that less heat exchange area and less solution are needed, and the cost is greatly reduced; on the other hand, through setting up cloth liquid device, can evenly spray the solution in the condensation segment of each gravity type heat pipe, with condensation segment fully contact, improve heat exchange efficiency.

Claims (9)

1. A smoke absorption type cold water/heat pump unit of a heat pipe type generator comprises a generator; the generator is characterized by comprising a shell, wherein the inner cavity of the shell is divided into a solution cavity and a smoke cavity which are arranged up and down; the inner cavity of the shell is also provided with a plurality of gravity type heat pipes, each gravity type heat pipe comprises a condensation section and an evaporation section, the evaporation section is positioned in the smoke cavity, the condensation section is positioned in the solution cavity, and the length of the evaporation section is larger than that of the condensation section.

2. The flue gas absorption cold water/heat pump unit of a heat pipe type generator according to claim 1, wherein the solution chamber is internally provided with a liquid distribution device, and the liquid distribution device is positioned above a condensation section of the gravity type heat pipe.

3. The flue gas absorption cold water/heat pump unit of a heat pipe type generator according to claim 2, wherein the solution cavity is positioned above the flue gas cavity, the flue gas cavity is provided with a flue gas inlet and a flue gas outlet, and the top of the flue gas cavity is provided with a steam outlet; the solution cavity is provided with a dilute solution inlet and a concentrated solution outlet, and the bottom of the solution cavity is provided with a condensate outlet; the dilute solution inlet is communicated with the liquid distribution device.

4. The flue gas absorption chiller/heat pump unit of heat pipe type generator according to claim 1, wherein the length of the evaporation section of the gravity type heat pipe is 100-3000mm, and the length of the condensation section is 50-1000mm.

5. The flue gas absorption chiller/heat pump unit of heat pipe generator according to claim 4 wherein the length of the evaporator section of the gravity type heat pipe is 500-1500mm and the length of the condenser section is 100-500mm.

6. The flue gas absorbing cold water/heat pump unit of a heat pipe generator according to claim 1, wherein the outer surface of the evaporation section is coated with teflon coating, enamel coating or heat and acid resistant paint.

7. The flue gas absorption chiller/heat pump unit of heat pipe generator according to claim 1, wherein the material of the condensing section is the same as that of the evaporating section, or the material of the condensing section is low carbon steel or low alloy steel.

8. The flue gas absorption chiller/heat pump unit of a heat pipe generator according to claim 1 wherein the surface of the evaporator section and/or the condenser section of the gravity type heat pipe is smooth and flat.

9. The flue gas absorption cold water/heat pump unit according to claim 1, wherein the surface of the evaporation section and/or the condensation section of the gravity type heat pipe is provided with annular or spiral fins or vertical diversion grooves or diversion ribs.