A lithium bromide refrigeration coupled hydrate cold storage system and method thereof

Abstract

A lithium bromide refrigeration coupled hydrate cold storage system and method thereof, belonging to the field of energy. A heat exchange tube is arranged in the hydrate generation kettle, the output end of the heat exchange tube is connected to the absorber, the output end of the absorber is connected to the solution pump I; the output end of the solution pump I is connected to the input end I of the low-temperature heat exchanger, the output end I of the low-temperature heat exchanger is connected to the input end I of the high-temperature heat exchanger; the output end I of the high-temperature heat exchanger is connected to the high-pressure generator; the output end of the mixer I is connected to the input end I of the condenser, and the output end I of the condenser is connected to the input end of the heat exchange tube in the hydrate generation kettle. The present invention drives the lithium bromide refrigeration subsystem to provide cold for the hydrate and store it, and when refrigeration is needed, the hydrate is controlled to decompose and release the stored cold. No pollutants are discharged in this process, and the system is driven by the medium and low temperature waste heat of the industrial production process, and waste heat recovery is realized at the same time.

Description

Technical Field

[0001] The invention relates to a lithium bromide refrigeration coupled hydrate cold storage system and a method thereof, belonging to the field of energy. Background Art

[0002] The lithium bromide absorption refrigeration unit is a closed-loop cycle that uses unrecovered waste heat to drive the unit to provide cooling or refrigeration. Since low-temperature waste heat can be used to generate cooling benefits, the input energy is equivalent to free. Therefore, in processes where low-temperature waste heat is available and cooling is required, the use of lithium bromide absorption refrigeration machines is beneficial to improving the energy efficiency of the process. Since lithium bromide is highly corrosive, there are high requirements for anti-corrosion measures and environment when storing lithium bromide absorption refrigeration units after refrigeration, so improvements are made to them. Summary of the invention

[0003] The purpose of the present invention is to solve the above-mentioned problems existing in the background technology and to provide a lithium bromide refrigeration coupled hydrate cold storage system and method thereof.

[0004] The present invention achieves the above-mentioned purpose by adopting the following technical solutions:

[0005] A lithium bromide refrigeration coupled hydrate cold storage system comprises a cold storage system and a refrigeration system. The cold storage system comprises a hydrate generation kettle. The refrigeration system comprises a heat exchange tube arranged outside the hydrate generation kettle to provide cold for the hydrate inside the hydrate generation kettle.

[0006] The refrigeration system further comprises an absorber, a solution pump I, a low-temperature heat exchanger, a high-temperature heat exchanger, a high-pressure generator, a low-pressure generator, a mixer I and a condenser; the output end of the heat exchange tube is connected to the absorber, and the output end of the absorber is connected to the solution pump I; the output end of the solution pump I is connected to the input end I of the low-temperature heat exchanger, and the output end I of the low-temperature heat exchanger is connected to the input end I of the high-temperature heat exchanger; the output end I of the high-temperature heat exchanger is connected to the high-pressure generator; the two output ends of the high-pressure generator are respectively connected to the low-pressure generator and the high-temperature heat exchanger; the two output ends of the low-pressure generator are respectively connected to the mixer I and the low-temperature heat exchanger; the output end of the mixer I is connected to the input end I of the condenser, and the output end I of the condenser is connected to the input end of the heat exchange tube in the hydrate formation kettle;

[0007] The output end of the hydrate generation kettle is connected to the hydrate decomposer, and the hydrate decomposer is connected to the separator III; the steam output end of the separator III is connected to the compressor, and the solution output end of the separator III is connected to the solution pump II; the output ends of the solution pump II and the compressor are both connected to the mixer II; the output end of the mixer II is connected to the input end of the hydrate generation kettle.

[0008] A method for using a lithium bromide refrigeration coupled hydrate cold storage system, the method comprising the following steps:

[0009] Step 1: After the refrigerant water in the hydrate generation kettle evaporates, it is mixed with the lithium bromide concentrated solution from the low-temperature heat exchanger in the absorber, cooled by cooling water to form a lithium bromide dilute solution, and then pressurized and transported to the low-temperature heat exchanger by the solution pump I to heat with the lithium bromide concentrated solution from the low-pressure generator, enter the high-temperature heat exchanger to heat with the lithium bromide intermediate solution from the high-pressure generator, enter the high-pressure generator to be heated by an external heat source to generate refrigerant vapor and lithium bromide intermediate solution, and the intermediate solution releases heat through the high-temperature heat exchanger and enters the low-pressure generator to be heated by the refrigerant steam to generate refrigerant vapor and lithium bromide concentrated solution. The concentrated solution releases heat through the low-temperature heat exchanger and enters the absorber;

[0010] Step 2: Refrigerant steam: The refrigerant steam from the high-pressure generator enters the low-pressure generator to heat the intermediate solution in the low-pressure generator, releases the latent heat of vaporization, condenses through the throttle valve, and then enters the condenser with the refrigerant steam from the low-pressure generator to be condensed into refrigerant water by cooling water. The refrigerant water enters the hydrate formation kettle, releases cold energy, evaporates into refrigerant steam, and enters the absorber;

[0011] Step 3: Cooling water: first passes through the absorber to release cold energy, and then enters the condenser to cool the refrigerant vapor;

[0012] Step 4: The remaining cold of the hydrate in the hydrate generation kettle is obtained through the steps 1 to 3. The hydrate formed in the hydrate generation kettle is depressurized by a throttle valve and enters the hydrate decomposer to release the stored cold to supply the user. After the hydrate is completely decomposed, it enters the gas-liquid separator III, the solution is pressurized by the liquid pump II, the gas is pressurized by the compressor, and the two are mixed by the mixer II and enter the hydrate generation kettle to generate hydrate again.

[0013] Compared with the prior art, the present invention has the following beneficial effects: the present invention utilizes an external heat source to drive the lithium bromide refrigeration subsystem to provide cold for hydrates and store it; when refrigeration is needed, the hydrates are controlled to decompose and release the stored cold; no pollutants are emitted during this process, and the system is driven by medium and low temperature waste heat from the industrial production process, while waste heat recovery is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of a lithium bromide refrigeration coupled hydrate cold storage system of the present invention. DETAILED DESCRIPTION

[0015] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0016] Specific implementation method 1: Figure 1 As shown, this embodiment records a lithium bromide refrigeration coupled hydrate cold storage system, including a cold storage system and a refrigeration system, wherein the cold storage system includes a hydrate generation kettle 7; the refrigeration system includes a heat exchange tube arranged on the outside of the hydrate generation kettle 7 to provide cooling for the hydrate inside the hydrate generation kettle 7.

[0017] The refrigeration system also includes an absorber 6, a solution pump I5, a low-temperature heat exchanger 3, a high-temperature heat exchanger 2, a high-pressure generator 1, a low-pressure generator 10, a mixer I9 and a condenser 8; the output end of the heat exchange tube is connected to the absorber 6, and the output end of the absorber 6 is connected to the solution pump I5; the output end of the solution pump I5 is connected to the input end I of the low-temperature heat exchanger 3, and the output end I of the low-temperature heat exchanger 3 is connected to the input end I of the high-temperature heat exchanger 2; the output end I of the high-temperature heat exchanger 2 is connected to the high-pressure generator 1; the two output ends of the high-pressure generator 1 are respectively connected to the low-pressure generator 10 and the high-temperature heat exchanger 2; the two output ends of the low-pressure generator 10 are respectively connected to the mixer I9 and the low-temperature heat exchanger 3; the output end of the mixer I9 is ​​connected to the input end I of the condenser 8, and the output end I of the condenser 8 is connected to the input end of the heat exchange tube in the hydrate generation kettle 7.

[0018] The output end of the hydrate generation kettle 7 is connected to the hydrate decomposer 11, and the hydrate decomposer 11 is connected to the separator III 12; the steam output end of the separator III 12 is connected to the compressor 13, and the solution output end of the separator III 12 is connected to the solution pump II 15; the output ends of the solution pump II 15 and the compressor 13 are both connected to the mixer II 14; the output end of the mixer II 14 is connected to the input end of the hydrate generation kettle 7. The hydrate generation kettle 7 is provided with cold through lithium bromide refrigeration, and cold is stored through hydrates.

[0019] The hydrate is one of THF and TBAB.

[0020] The high-temperature heat exchanger 2 uses the waste heat of the lithium bromide intermediate solution to heat the lithium bromide dilute solution; the low-pressure generator 10 controls the concentration of the lithium bromide concentrated solution by the heat exchange temperature difference between the refrigerant water vapor and the lithium bromide intermediate solution; the mixer I9 mixes the refrigerant water vapor after heat exchange with the separated refrigerant water vapor; the hydrate formation kettle 7 controls the complete evaporation of the refrigerant water to provide cooling capacity for hydrate formation; the high-pressure generator 1 controls the concentration of the intermediate solution by the heat exchange temperature difference between the high-temperature hot water and the lithium bromide dilute solution; the absorber 6 uses the external cooling water to absorb the heat after the refrigerant water vapor and the lithium bromide concentrated solution are mixed; the condenser 8 controls the heat exchange temperature difference to condense all the refrigerant vapor; the low-temperature heat exchanger 3 uses the waste heat of the lithium bromide concentrated solution to heat the lithium bromide dilute solution.

[0021] The high-pressure generator 1 includes a heat exchanger Ⅰ101 and a separator Ⅰ102; the input end Ⅰ of the heat exchanger Ⅰ101 is connected to the high-temperature heat exchanger 2, and the output end of the heat exchanger Ⅰ101 is connected to the separator Ⅰ102. The separator Ⅰ102 is provided with a liquid output end and a steam output end, and its liquid output end is connected to the input end Ⅱ of the high-temperature heat exchanger 2, and its steam output end is connected to the low-pressure generator 10.

[0022] The low-pressure generator 10 includes a heat exchanger II1001 and a separator II1002; the input end I of the heat exchanger II1001 is connected to the steam output end of the separator I102, and the output end I of the heat exchanger II1001 is connected to the mixer I9; the output end II of the high-temperature heat exchanger 2 is connected to the input end II of the heat exchanger II1001, the output end II of the heat exchanger II1001 is connected to the separator II1002, the steam output end of the separator II1002 is connected to the mixer I9, the solution output end of the separator II1002 is connected to the input end II of the low-temperature heat exchanger 3, and the output end II of the low-temperature heat exchanger 3 is connected to the absorber 6.

[0023] The absorber 6 is provided with a heat exchange tube, and the output end of the heat exchange tube is connected to the input end II of the condenser 8 .

[0024] Throttle valves 4 are provided between the high-temperature heat exchanger 2 and the heat exchanger II 1001 , between the low-temperature heat exchanger 3 and the absorber 6 , between the heat exchanger II 1001 and the mixer I 9 , and between the condenser 8 and the hydrate forming kettle 7 .

[0025] The input end II of the heat exchanger I 101 is connected to an external heat source, which includes low-temperature waste heat generated in an industrial production process and can be utilized.

[0026] A throttle valve 4 is provided between the hydrate generating kettle 7 and the hydrate decomposer 11 .

[0027] A method for using a lithium bromide refrigeration coupled hydrate cold storage system, the method comprising the following steps:

[0028] Step 1: The coldness of the hydrate in the hydrate generating kettle 7 is obtained through the steps 1 to 3. After the refrigerant water in the hydrate generating kettle 7 evaporates, it is mixed with the lithium bromide concentrated solution from the low-temperature heat exchanger 3 along the path S1-8 along the path S2-10 in the absorber 6, and is cooled by cooling water to form a dilute lithium bromide solution. It is pressurized by the solution pump Ⅰ5 and transported to the low-temperature heat exchanger 3 through the input end Ⅰ along the path S2-2. In the low-temperature heat exchanger 3, the lithium bromide concentrated solution is heated by the solution output end of the separator Ⅱ 1002 in the low-pressure generator 10 along the path S2-9, and then output from the output end Ⅰ of the low-temperature heat exchanger 3 along the path S2-3 to enter the high-temperature In the heat exchanger 2, the lithium bromide intermediate solution is heated along the path S2-6 from the separator Ⅰ102 in the high-pressure generator 1 in the high-temperature heat exchanger 2, and then output from the output end Ⅰ of the high-temperature heat exchanger 2 along the path S2-4 to enter the heat exchanger Ⅰ101 in the high-pressure generator 1 and is heated by the external heat source along the path S0-0 to generate refrigerant vapor and lithium bromide intermediate solution. After the intermediate solution releases heat through the high-temperature heat exchanger 2, it enters the heat exchanger Ⅱ1001 of the low-pressure generator 10 and is heated by the refrigerant vapor from the high-pressure heat exchanger 1 along the path S1-1 to generate refrigerant vapor and lithium bromide concentrated solution. The concentrated solution releases heat through the low-temperature heat exchanger 3 and enters the absorber 6;

[0029] Step 2: Refrigerant steam: The refrigerant steam from the high-pressure generator 1 enters the low-pressure generator 10 along the path S1-1 to heat the intermediate solution in the low-pressure generator 10, releases the latent heat of vaporization, condenses along the path S1-2, passes through the throttle valve 4, and is mixed with the refrigerant steam from the path S1-3 in the mixer I9, and then enters the condenser 8 along the path S1-4 to be condensed into refrigerant water by cooling water, and the refrigerant water enters the hydrate generation kettle 7, releases cold energy and is absorbed by the carbon dioxide hydrate in the hydrate generation kettle 7, and the refrigerant water evaporates into refrigerant steam and enters the absorber 6;

[0030] Step 3: Cooling water: firstly passes through the absorber 6 along the path S1-7 to release the cold, and then enters the condenser 8 along the path S1-8 to cool the refrigerant vapor.

[0031] Step 4: The carbon dioxide hydrate formed in the hydrate generating kettle 7 is depressurized along the path h3-1 through the throttle valve 4 and enters the hydrate decomposer 11 to release the stored cold energy to supply the user. After the carbon dioxide hydrate is completely decomposed, it enters the gas-liquid separator III 12 along the path h3-2, and the water and tetrahydrofuran mixture is pressurized along the path h3-4 through the liquid pump II 15, and the carbon dioxide gas is pressurized along the path h3-3 through the compressor 13. The two are mixed through the mixer II 14 and enter the hydrate generating kettle 7 to generate carbon dioxide hydrate again.

[0032] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other forms of assembly without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0033] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A lithium bromide refrigeration coupled hydrate cold storage system, characterized in that: It comprises a cold storage system and a refrigeration system, wherein the cold storage system comprises a hydrate generation kettle (7); the refrigeration system comprises a heat exchange tube arranged outside the hydrate generation kettle (7) to provide cold energy for the hydrate inside the hydrate generation kettle (7); The refrigeration system further comprises an absorber (6), a solution pump I (5), a low-temperature heat exchanger (3), a high-temperature heat exchanger (2), a high-pressure generator (1), a low-pressure generator (10), a mixer I (9) and a condenser (8); the output end of the heat exchange tube is connected to the absorber (6), the output end of the absorber (6) is connected to the solution pump I (5); the output end of the solution pump I (5) is connected to the input end I of the low-temperature heat exchanger (3), the output end I of the low-temperature heat exchanger (3) is connected to the output end I of the high-temperature heat exchanger (2); The high-temperature heat exchanger (2) is connected to an input end I; the output end I of the high-temperature heat exchanger (2) is connected to the high-pressure generator (1); the two output ends of the high-pressure generator (1) are respectively connected to the low-pressure generator (10) and the high-temperature heat exchanger (2); the two output ends of the low-pressure generator (10) are respectively connected to the mixer I (9) and the low-temperature heat exchanger (3); the output end of the mixer I (9) is connected to the input end I of the condenser (8), and the output end I of the condenser (8) is connected to the input end of the heat exchange tube in the hydrate formation kettle (7); The output end of the hydrate generating kettle (7) is connected to the hydrate decomposer (11), and the hydrate decomposer (11) is connected to the separator III (12); the steam output end of the separator III (12) is connected to the compressor (13), and the solution output end of the separator III (12) is connected to the solution pump II (15); the output ends of the solution pump II (15) and the compressor (13) are both connected to the mixer II (14); the output end of the mixer II (14) is connected to the input end of the hydrate generating kettle (7).

2. A lithium bromide refrigeration coupled hydrate cold storage system according to claim 1, characterized in that: The high-pressure generator (1) comprises a heat exchanger I (101) and a separator I (102); an input end I of the heat exchanger I (101) is connected to a high-temperature heat exchanger (2), an output end of the heat exchanger I (101) is connected to the separator I (102), and a liquid output end and a steam output end are provided on the separator I (102); the liquid output end is connected to an input end II of the high-temperature heat exchanger (2), and the steam output end is connected to the low-pressure generator (10).

3. A lithium bromide refrigeration coupled hydrate cold storage system according to claim 2, characterized in that: The low-pressure generator (10) comprises a heat exchanger II (1001) and a separator II (1002); the input end I of the heat exchanger II (1001) is connected to the steam output end of the separator I (102), and the output end I of the heat exchanger II (1001) is connected to the mixer I (9); the output end II of the high-temperature heat exchanger (2) is connected to the input end II of the heat exchanger II (1001), the output end II of the heat exchanger II (1001) is connected to the separator II (1002), the steam output end of the separator II (1002) is connected to the mixer I (9), the solution output end of the separator II (1002) is connected to the input end II of the low-temperature heat exchanger (3), and the output end II of the low-temperature heat exchanger (3) is connected to the absorber (6).

4. A lithium bromide refrigeration coupled hydrate cold storage system according to claim 3, characterized in that: A heat exchange tube is arranged in the absorber (6), and the output end of the heat exchange tube is connected to the input end II of the condenser (8).

5. The lithium bromide refrigeration coupled hydrate cold storage system according to claim 4, characterized in that: Throttle valves (4) are provided between the high-temperature heat exchanger (2) and the heat exchanger II (1001), between the low-temperature heat exchanger (3) and the absorber (6), between the heat exchanger II (1001) and the mixer I (9), and between the condenser (8) and the hydrate forming kettle (7).

6. The lithium bromide refrigeration coupled hydrate cold storage system according to claim 5, characterized in that: The input end II of the heat exchanger I (101) is connected to an external heat source.

7. The lithium bromide refrigeration coupled hydrate cold storage system according to claim 6, characterized in that: A throttle valve (4) is provided between the hydrate generating kettle (7) and the hydrate decomposer (11).

8. The method for using the lithium bromide refrigeration coupled hydrate cold storage system according to claim 7, characterized in that: The method of use comprises the following steps: Step 1: After the refrigerant water in the hydrate generation kettle (7) is evaporated, it is mixed with the lithium bromide concentrated solution from the low-temperature heat exchanger (3) in the absorber (6), cooled by cooling water to form a lithium bromide dilute solution, and then pressurized and transported to the low-temperature heat exchanger (3) by the solution pump I (5) to heat with the lithium bromide concentrated solution from the low-pressure generator (10), enter the high-temperature heat exchanger (2) to heat with the lithium bromide intermediate solution from the high-pressure generator (1), enter the high-pressure generator (1) to be heated by an external heat source to generate refrigerant vapor and lithium bromide intermediate solution, the intermediate solution passes through the high-temperature heat exchanger (2) to release heat, and then enters the low-pressure generator (10) to be heated by the refrigerant steam to generate refrigerant vapor and lithium bromide concentrated solution, and the concentrated solution passes through the low-temperature heat exchanger (3) to release heat and enter the absorber (6); Step 2: Refrigerant steam: The refrigerant steam from the high pressure generator (1) enters the low pressure generator (10) to heat the intermediate solution in the low pressure generator (10), releases the latent heat of vaporization, condenses through the throttle valve (4), and then enters the condenser (8) with the refrigerant steam from the low pressure generator (10) to be condensed into refrigerant water by cooling water. The refrigerant water enters the hydrate forming kettle (7), releases the cold energy, evaporates into refrigerant steam, and enters the absorber (6); Step 3: Cooling water: first passes through the absorber (6) to release cold energy, and then enters the condenser (8) to cool the refrigerant vapor; Step 4: The cold energy of the hydrate in the hydrate generation kettle (7) is obtained through the steps 1 to 3. The hydrate formed in the hydrate generation kettle (7) is depressurized by the throttle valve (4) and enters the hydrate decomposer (11) to release the stored cold energy to supply the user. After the solution is completely decomposed, it enters the gas-liquid separator III (12). The liquid is pressurized by the solution pump II (15), and the gas is pressurized by the compressor (13). The two are mixed by the mixer II (14) and enter the hydrate generation kettle (7) to generate hydrate again.

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