Carbon dioxide gas waste heat recovery system

Abstract

This utility model discloses a carbon dioxide gas waste heat recovery and utilization system in the field of waste heat recovery technology, including: an absorption chiller unit, and the waste heat recovery and utilization system further includes a first heat exchanger and a second heat exchanger connected in sequence; the first heat exchanger and the second heat exchanger are used to absorb heat and cool carbon dioxide gas in sequence, and the absorption chiller unit is used to use the heat absorbed by the first heat exchanger for cooling to absorb heat and cool carbon dioxide gas discharged from the second heat exchanger again; this application uses high-temperature carbon dioxide gas to be cooled by circulating high-temperature water, and the hot water obtained is used as a driving force to produce refrigerant through a low-temperature absorption chiller unit to indirectly cool carbon dioxide, or directly cool carbon dioxide, which can make full use of waste heat conditions, achieve energy saving and emission reduction, and is applicable to carbon dioxide gas cooling and similar processes.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery, specifically to a carbon dioxide gas waste heat recovery and utilization system. Background Technology

[0002] In existing carbon dioxide gas processing technologies, the high-temperature, high-pressure carbon dioxide material from the raw material compressor outlet typically has an exhaust temperature as high as approximately 175°C. To meet the demand for low-temperature carbon dioxide in subsequent processes, multi-stage cooling methods are commonly used. These methods involve cooling the carbon dioxide gas to below -45°C using circulating cooling water (currently produced from lithium bromide to indirectly cool the carbon dioxide gas) and electric refrigeration units. However, these methods only rely on circulating cooling water to reduce the carbon dioxide gas temperature to around 40°C. Carbon dioxide below 40°C requires electric refrigeration units to generate cryogenic liquid for cooling, resulting in low unit efficiency and high power consumption. Indirectly cooling the carbon dioxide gas with cryogenic liquid requires an additional water pump, which consumes a lot of power and does not fully utilize waste heat, leading to heat waste. Utility Model Content

[0003] The purpose of this invention is to provide a carbon dioxide gas waste heat recovery and utilization system, which solves the problems of existing equipment not fully utilizing waste heat and consuming a lot of energy.

[0004] The present invention achieves the above objectives through the following technical solution: a carbon dioxide gas waste heat recovery and utilization system, comprising: an absorption chiller unit, wherein the waste heat recovery and utilization system further comprises a first heat exchanger and a second heat exchanger connected in sequence. The first heat exchanger and the second heat exchanger are used to absorb heat and cool carbon dioxide gas in sequence. The absorption chiller is used to use the heat absorbed by the first heat exchanger for cooling to absorb heat and cool carbon dioxide gas discharged from the second heat exchanger again.

[0005] Preferably, the absorption chiller is a low-temperature absorption chiller.

[0006] Preferably, the absorption chiller unit includes a generator, a condenser, an evaporator, and an absorber, wherein the heat source inlet and outlet of the generator are connected to the first heat exchanger.

[0007] Preferably, the waste heat recovery system further includes a third heat exchanger, which is connected to the second heat exchanger and to the refrigerant inlet and outlet of the evaporator.

[0008] Preferably, the refrigerant inlet of the evaporator is connected to the second heat exchanger.

[0009] Preferably, the circulating water outlet of the absorber is connected to the circulating water inlet of the condenser.

[0010] The beneficial effects of this utility model are as follows: the high-temperature carbon dioxide gas is cooled by circulating high-temperature water, and the hot water obtained is used as a driving force to produce a low-temperature absorption refrigeration unit to indirectly cool the carbon dioxide or directly cool the carbon dioxide. This can make full use of waste heat conditions, achieve energy saving and emission reduction, and is applicable to carbon dioxide gas cooling and similar processes. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of one embodiment of the carbon dioxide gas waste heat recovery and utilization system of this utility model; Figure 2 This is a schematic diagram of another embodiment of the carbon dioxide gas waste heat recovery and utilization system of this utility model.

[0012] In the diagram: 1. First heat exchanger; 2. Second heat exchanger; 3. Absorption refrigeration unit; 301. Generator; 302. Condenser; 303. Evaporator; 304. Absorber; 4. Third heat exchanger. Detailed Implementation

[0013] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0014] Example 1 Please see Figure 1 A carbon dioxide gas waste heat recovery and utilization system includes: an absorption chiller unit 3, a first heat exchanger 1 and a second heat exchanger 2; the shell-side outlet of the first heat exchanger 1 is connected to the shell-side inlet of the second heat exchanger 2, and a heat exchange medium (such as water) circulates inside the heat exchange pipes of the first heat exchanger 1, and a heat exchange medium (such as cooling water) circulates inside the heat exchange pipes of the second heat exchanger 2. The absorption chiller unit 3 includes a generator 301, a condenser 302, an evaporator 303 and an absorber 304. The heat source inlet and outlet of the generator 301 are respectively connected to the two ends of the heat exchange pipe of the first heat exchanger 1.

[0015] It should be noted that the connection relationships between the various components of the absorption chiller unit 3 are existing technologies and will not be described in detail here.

[0016] Please see Figure 1 The waste heat recovery system also includes a third heat exchanger 4. The shell-side inlet of the third heat exchanger 4 is connected to the shell-side outlet of the second heat exchanger 2. The two ends of the heat exchange pipe of the third heat exchanger 4 are connected to the inlet and outlet of the refrigerant of the evaporator 303, respectively. The refrigerant (such as water) circulates inside the heat exchange pipe of the third heat exchanger 4.

[0017] It should be noted that the waste heat recovery system works as follows: carbon dioxide gas enters the shell of the first heat exchanger 1 and exchanges heat with the heat exchange medium inside the heat exchange pipes. The heat exchange medium absorbs the heat from the carbon dioxide, and the cooled carbon dioxide enters the shell of the second heat exchanger 2 and exchanges heat with the cooling water inside the heat exchange pipes to further absorb heat and cool the carbon dioxide gas. The cooled carbon dioxide then enters the third heat exchanger 4. The heat exchange medium that has absorbed heat in the first heat exchanger 1 enters the generator 301 of the absorption chiller unit 3 as a heat source to heat the rich solution therein and produce gaseous refrigerant. The gaseous refrigerant enters the condenser 302 and condenses into liquid refrigerant, then enters the evaporator 303, absorbs the heat from the refrigerant, vaporizes, and enters the absorber 304 to be absorbed. The refrigerant discharged from the evaporator 303 flows inside the heat exchange pipes of the third heat exchanger 4 and exchanges heat with the carbon dioxide to further cool the carbon dioxide.

[0018] In this embodiment, as a further optimization, please refer to... Figure 1 Absorption refrigeration unit 3 is a low-temperature absorption refrigeration unit, and the refrigerant therein can be ammonia.

[0019] In this embodiment, as a further optimization, please refer to... Figure 1 The circulating water outlet of the absorber 304 is connected to the circulating water inlet of the condenser 302; external cooling water sequentially cools the absorber 304 and the condenser 302.

[0020] Example 2 Please see Figure 2 Based on Example 1, the third heat exchanger 4 is removed, and the shell-side outlet of the second heat exchanger 2 is connected to the refrigerant inlet of the evaporator 303.

[0021] It should be noted that the waste heat recovery system works as follows: carbon dioxide gas enters the shell of the first heat exchanger 1 and exchanges heat with the heat exchange medium inside the heat exchange pipe. The heat exchange medium absorbs the heat from the carbon dioxide, and the cooled carbon dioxide enters the shell of the second heat exchanger 2 and exchanges heat with the cooling water inside the heat exchange pipe. This is used to further absorb heat and cool the carbon dioxide gas. The cooled carbon dioxide then enters the refrigerant pipe of the evaporator 303. The heat exchange medium that has absorbed heat in the first heat exchanger 1 enters the generator 301 of the absorption chiller unit 3 as a heat source to heat the rich solution therein and produce gaseous refrigerant. The gaseous refrigerant enters the condenser 302 and condenses into liquid refrigerant. Then it enters the evaporator 303, absorbs the heat from the carbon dioxide in the refrigerant pipe, vaporizes, and enters the absorber 304 to be absorbed. The cooled carbon dioxide is discharged from the refrigerant pipe.

[0022] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A carbon dioxide gas waste heat recovery and utilization system, comprising: An absorption chiller unit (3) is characterized in that the waste heat recovery and utilization system further includes a first heat exchanger (1) and a second heat exchanger (2) connected in sequence. The first heat exchanger (1) and the second heat exchanger (2) are used to absorb heat and cool down carbon dioxide gas in sequence. The absorption chiller (3) is used to use the heat absorbed by the first heat exchanger (1) to cool down the carbon dioxide gas discharged from the second heat exchanger (2) again.

2. The carbon dioxide gas waste heat recovery and utilization system according to claim 1, characterized in that, The absorption chiller unit (3) is a low-temperature absorption chiller unit.

3. The carbon dioxide gas waste heat recovery and utilization system according to claim 1, characterized in that, The absorption chiller unit (3) includes a generator (301), a condenser (302), an evaporator (303) and an absorber (304), and the heat source inlet and outlet of the generator (301) are connected to the first heat exchanger (1).

4. A carbon dioxide gas waste heat recovery and utilization system according to claim 3, characterized in that, The waste heat recovery system also includes a third heat exchanger (4), which is connected to the second heat exchanger (2) and is connected to the refrigerant inlet and outlet of the evaporator (303).

5. A carbon dioxide gas waste heat recovery and utilization system according to claim 3, characterized in that, The refrigerant inlet of the evaporator (303) is connected to the second heat exchanger (2).

6. A carbon dioxide gas waste heat recovery and utilization system according to claim 3, characterized in that, The circulating water outlet of the absorber (304) is connected to the circulating water inlet of the condenser (302).

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