Natural gas advanced treatment waste heat comprehensive utilization system

Abstract

The utility model relates to the technical field of energy recycling, in particular to a natural gas advanced treatment waste heat comprehensive utilization system which comprises a waste heat system. The waste heat utilization system is connected with a waste heat medium outlet of the waste heat system; and the heat utilization system is connected with a high-temperature medium outlet of the waste heat utilization system. The comprehensive waste heat utilization system for deep treatment of natural gas can effectively utilize waste heat, the cooling cost of the waste heat is saved, and the cost of steam used by the reboiler is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of energy recycling, in particular to a system for comprehensive utilization of waste heat from deep treatment of natural gas. Background Art

[0002] In natural gas pretreatment, because the front-end process requires waste hot water at 50 to 95°C, cooling water is usually used for direct cooling, air cooling, or indirect cooling as a driving energy source for lithium bromide. However, as a driving energy source for lithium bromide refrigerators, it can only be cooled to 55°C at present, which cannot meet the on-site process requirements and requires secondary cooling to ensure that the outlet temperature is 50°C. As a second-type lithium bromide absorption heat pump or hot water lithium bromide absorption refrigerator, the waste heat can only be cooled to about 65°C, which also requires secondary cooling, and the efficiency is less than 0.5, which is low in efficiency and serious energy waste. In addition, the on-site process requires steam above 130°C to heat the reboiler. Most of the steam currently used is purchased from outside, and the operating cost is high. Utility Model Content

[0003] In view of this, the technical problem to be solved by the utility model is to provide a natural gas deep comprehensive utilization system, which can effectively utilize waste heat, save the cooling cost of waste heat, and reduce the steam cost used in the reboiler.

[0004] The present application provides a system for comprehensive utilization of waste heat from deep processing of natural gas, comprising:

[0005] Waste heat system;

[0006] A waste heat utilization system connected to a waste heat medium outlet of the waste heat system;

[0007] A heat utilization system connected to the high-temperature medium outlet of the waste heat utilization system.

[0008] Preferably, the waste heat system includes at least one of a mixed refrigerant device, a heat transfer oil fume device, a pretreatment device regenerator, and a high temperature stable light hydrocarbon device;

[0009] The waste heat utilization system includes at least one of an electrically driven heat pump unit, a water vapor compressor, a low-pressure flash evaporator and a gas-liquid separator;

[0010] The heat utilizing system comprises at least one of a reboiler and a reaction tower.

[0011] Preferably, the waste heat medium outlet of the waste heat utilization system is connected to the waste heat medium inlet of the waste heat system.

[0012] Preferably, the natural gas deep comprehensive utilization system also includes an indirect heat exchange system; the high-temperature medium inlet of the indirect heat exchange system is connected to the high-temperature medium outlet of the waste heat utilization system, and the high-temperature medium outlet of the indirect heat exchange system is connected to the high-temperature medium inlet of the heat utilization system.

[0013] Preferably, the natural gas deep comprehensive utilization system also includes a heat exchange auxiliary system; the waste heat medium inlet of the heat exchange auxiliary system is connected to the waste heat medium outlet of the waste heat utilization system, and the waste heat medium outlet of the heat exchange auxiliary system is connected to the waste heat medium inlet of the waste heat system.

[0014] Preferably, the natural gas deep comprehensive utilization system further comprises the lithium bromide module;

[0015] The waste heat medium inlet of the lithium bromide module is connected to the waste heat medium outlet of the waste heat system;

[0016] The waste heat medium outlet of the lithium bromide module is connected to the waste heat medium inlet of the waste heat utilization system.

[0017] Preferably, the natural gas deep comprehensive utilization system comprises:

[0018] Waste heat system;

[0019] Waste heat utilization system; the waste heat utilization system includes a primary electric drive heat pump, a secondary electric drive heat pump and a water vapor compressor;

[0020] A heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer;

[0021] Heat system;

[0022] The waste heat medium inlet of the first-stage electric-driven heat pump is connected to the waste heat medium outlet of the waste heat system, and the high-temperature medium outlet of the first-stage electric-driven heat pump is connected to the heat-using system;

[0023] The waste heat medium inlet of the secondary electric-driven heat pump is connected to the waste heat medium outlet of the primary electric-driven heat pump, and the waste heat medium outlet of the secondary electric-driven heat pump is connected to the waste heat medium inlet of the deethanizer;

[0024] The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system;

[0025] The high-temperature medium inlet of the water vapor compressor is connected to the high-temperature medium outlet of the two-stage electrically driven heat pump, and the high-temperature medium outlet of the water vapor compressor is connected to the heat using system.

[0026] Preferably, the natural gas deep comprehensive utilization system comprises:

[0027] Waste heat system;

[0028] A waste heat utilization system; the waste heat utilization system comprises a primary electric-driven heat pump, a secondary electric-driven heat pump, a first water vapor compressor and a second water vapor compressor;

[0029] A heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer;

[0030] Heat system;

[0031] The waste heat medium inlet of the first-stage electric-driven heat pump is connected to the waste heat medium outlet of the waste heat system, and the high-temperature medium outlet of the first-stage electric-driven heat pump is connected to the cold medium inlet of the first water vapor compressor;

[0032] The waste heat medium inlet of the secondary electric-driven heat pump is connected to the waste heat medium outlet of the primary electric-driven heat pump, and the waste heat medium outlet of the secondary electric-driven heat pump is connected to the waste heat medium inlet of the deethanizer;

[0033] The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system;

[0034] The high-temperature medium inlet of the first water vapor compressor is connected to the high-temperature medium outlet of the first-stage electrically driven heat pump, and the high-temperature medium outlet of the first water vapor compressor is connected to the heat using system;

[0035] The high-temperature medium inlet of the second water vapor compressor is connected to the high-temperature medium outlet of the two-stage electrically driven heat pump, and the high-temperature medium outlet of the second water vapor compressor is connected to the heat using system.

[0036] Preferably, the natural gas deep comprehensive utilization system comprises:

[0037] Waste heat system;

[0038] Waste heat utilization system; the waste heat utilization system includes an electrically driven heat pump, a water vapor compressor, a low-pressure flash evaporator and a gas-liquid separator;

[0039] A heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer;

[0040] Heat system;

[0041] The waste heat medium inlet of the low-pressure flash evaporator is connected to the waste heat medium outlet of the waste heat system, and the low-temperature steam outlet of the low-pressure flash evaporator is connected to the low-temperature steam inlet of the water vapor compressor;

[0042] The heat medium outlet of the water vapor compressor is connected to the heat medium inlet of the gas-liquid separator; the steam outlet of the gas-liquid separator is connected to the heat using system; the reflux liquid outlet of the gas-liquid separator is connected to the reflux liquid inlet of the low-pressure flash evaporator;

[0043] The first medium inlet and the second medium inlet of the electrically driven heat pump are both connected to the cold medium outlet of the low-pressure flash evaporator, the first waste heat medium outlet of the electrically driven heat pump is connected to the waste heat medium inlet of the low-pressure flash evaporator, and the second waste heat medium outlet of the electrically driven heat pump is connected to the waste heat medium inlet of the deethanizer;

[0044] The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system.

[0045] Preferably, the natural gas deep comprehensive utilization system comprises:

[0046] Waste heat system;

[0047] LiBr module;

[0048] Waste heat utilization system; the waste heat utilization system includes a primary electric drive heat pump, a secondary electric drive heat pump and a water vapor compressor;

[0049] A heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer;

[0050] Heat system;

[0051] The waste heat medium inlet of the lithium bromide module is connected to the waste heat medium outlet of the waste heat system;

[0052] The waste heat medium inlet of the first-stage electric-driven heat pump is connected to the waste heat medium outlet of the lithium bromide module, and the high-temperature medium outlet of the first-stage electric-driven heat pump is connected to the heat-using system;

[0053] The waste heat medium inlet of the secondary electric-driven heat pump is connected to the waste heat medium outlet of the primary electric-driven heat pump, and the waste heat medium outlet of the secondary electric-driven heat pump is connected to the waste heat medium inlet of the deethanizer;

[0054] The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system;

[0055] The high-temperature medium inlet of the water vapor compressor is connected to the high-temperature medium outlet of the two-stage electrically driven heat pump, and the high-temperature medium outlet of the water vapor compressor is connected to the heat using system.

[0056] The utility model provides a natural gas deep comprehensive utilization system, comprising: a waste heat system; a waste heat utilization system connected to the waste heat medium outlet of the waste heat system; and a heat use system connected to the high temperature medium outlet of the waste heat utilization system. The natural gas deep comprehensive utilization system provided by the application can effectively utilize waste heat, save the cooling cost of waste heat, and reduce the steam cost used by the reboiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A diagram of a natural gas comprehensive utilization system provided for the first embodiment of the present invention;

[0058] Figure 2 A diagram of a natural gas comprehensive utilization system provided for a second embodiment of the present invention;

[0059] Figure 3 A diagram of a natural gas comprehensive utilization system provided by a third embodiment of the present invention;

[0060] Figure 4 A diagram of a natural gas deep comprehensive utilization system provided for the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0061] The following will be combined with the embodiments of the utility model to clearly and completely describe the technical solution of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0062] The utility model provides a system for comprehensive utilization of waste heat from deep processing of natural gas, comprising:

[0063] Waste heat system; the waste heat system is provided with a waste heat medium outlet;

[0064] A waste heat utilization system; the waste heat utilization system is provided with a waste heat medium inlet and a high temperature medium outlet; the waste heat medium inlet of the waste heat utilization system is connected to the waste heat medium outlet of the waste heat system;

[0065] A heat-using system; the heat-using system is provided with a high-temperature medium inlet; the high-temperature medium inlet of the heat-using system is connected to the high-temperature medium outlet of the waste heat utilization system.

[0066] In certain embodiments of the present application, the waste heat system includes at least one of a mixed refrigerant device, a heat transfer oil fume device, a pretreatment device regenerator, and a high-temperature stable light hydrocarbon device.

[0067] In certain embodiments of the present application, the waste heat system is further provided with a waste heat medium inlet.

[0068] The waste heat utilization system is used to recover the waste heat medium provided by the waste heat system, and to generate a high-temperature medium through heat exchange. In certain embodiments of the present application, the waste heat utilization system includes at least one of an electrically driven heat pump unit, a water vapor compressor, a low-pressure flash evaporator, and a gas-liquid separator. In certain embodiments of the present application, the waste heat utilization system includes an electrically driven heat pump unit and a water vapor compressor. In certain embodiments of the present application, the waste heat utilization system includes an electrically driven heat pump unit, a water vapor compressor, a low-pressure flash evaporator, and a gas-liquid separator.

[0069] In certain embodiments of the present application, the electrically driven heat pump unit includes at least one of a centrifugal heat pump unit, a screw heat pump unit and a vortex heat pump unit. The electric energy is used as a drive to recycle medium and low temperature cooling media and generate medium and high temperature hot water / steam.

[0070] In certain embodiments of the present application, the waste heat medium is not limited to 95°C waste hot water, and includes various hot water below 100°C, steam, exhaust gas, flue gas, materials and organic media.

[0071] In certain embodiments of the present application, the waste heat utilization system is further provided with a heat medium inlet and a waste heat medium outlet; the waste heat medium outlet of the waste heat utilization system is connected to the waste heat medium inlet of the waste heat system.

[0072] In certain embodiments of the present application, the heat system includes at least one of a reboiler and a reaction tower; specifically, it includes at least one of a deethanizer reboiler, an amine liquid tower bottom regeneration reboiler, and a methanol distillation tower reboiler.

[0073] In certain embodiments of the present application, the natural gas deep comprehensive utilization system also includes an indirect heat exchange system; the indirect heat exchange system is provided with a high-temperature medium inlet and a high-temperature medium outlet; the high-temperature medium inlet of the indirect heat exchange system is connected to the high-temperature medium outlet of the waste heat utilization system, and the high-temperature medium outlet of the indirect heat exchange system is connected to the high-temperature medium inlet of the heat utilization system.

[0074] In certain embodiments of the present application, the indirect heat exchange system is a gas-liquid separator.

[0075] In certain embodiments of the present application, the natural gas deep comprehensive utilization system also includes a heat exchange auxiliary system; the heat exchange auxiliary system is provided with a waste heat medium inlet and a waste heat medium outlet; the waste heat medium inlet of the heat exchange auxiliary system is connected to the waste heat medium outlet of the waste heat utilization system, and the waste heat medium outlet of the heat exchange auxiliary system is connected to the waste heat medium inlet of the waste heat system.

[0076] In certain embodiments of the present application, the auxiliary heat exchange system is a deethanizer.

[0077] In certain embodiments of the present application, the natural gas deep comprehensive utilization system also includes the lithium bromide module; the waste heat medium inlet of the lithium bromide module is connected to the waste heat medium outlet of the waste heat system; the waste heat medium outlet of the lithium bromide module is connected to the waste heat medium inlet of the waste heat utilization system.

[0078] In certain embodiments of the present application, the lithium bromide module is a lithium bromide refrigerator or a lithium bromide heat pump unit.

[0079] In the first embodiment of the present application, the natural gas deep comprehensive utilization system comprises:

[0080] Waste heat system; the waste heat system is provided with a waste heat medium outlet and a waste heat medium inlet;

[0081] Waste heat utilization system; the waste heat utilization system includes a primary electric drive heat pump, a secondary electric drive heat pump and a water vapor compressor;

[0082] A heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer;

[0083] Heat system;

[0084] The first-stage electric-driven heat pump is provided with a heat medium inlet, a high-temperature medium outlet, a waste heat medium inlet and a waste heat medium outlet; the waste heat medium inlet of the first-stage electric-driven heat pump is connected to the waste heat medium outlet of the waste heat system, and the high-temperature medium outlet of the first-stage electric-driven heat pump is connected to the heat using system;

[0085] The secondary electric-driven heat pump is provided with a heat medium inlet, a high-temperature medium outlet, a waste heat medium inlet and a waste heat medium outlet; the waste heat medium inlet of the secondary electric-driven heat pump is connected to the waste heat medium outlet of the primary electric-driven heat pump, and the waste heat medium outlet of the secondary electric-driven heat pump is connected to the waste heat medium inlet of the deethanizer;

[0086] The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system;

[0087] The high-temperature medium inlet of the water vapor compressor is connected to the high-temperature medium outlet of the two-stage electrically driven heat pump, and the high-temperature medium outlet of the water vapor compressor is connected to the heat using system.

[0088] Structure Figure 1 As shown, Figure 1 A diagram of a natural gas deep comprehensive utilization system provided by the first embodiment of the present invention, wherein 1 is a waste heat system, 2-1 is a primary electric-driven heat pump, 2-2 is a secondary electric-driven heat pump, 3 is a water vapor compressor, 4 is a heat exchange auxiliary system, and 5 is a heat utilization system.

[0089] Figure 1In the process, the 95°C waste hot water discharged from the waste heat medium outlet of the waste heat system is used as the waste heat source of the electric-driven heat pump unit. Specifically, the 95°C waste hot water discharged from the waste heat medium outlet of the waste heat system enters the first-stage electric-driven heat pump, and after heat exchange, provides 130°C saturated steam to directly heat the reboiler in the heat system;

[0090] The waste hot water discharged from the waste heat medium outlet of the first-stage electric-driven heat pump is cooled to 67°C and enters the second-stage electric-driven heat pump as the second-stage waste hot water. After heat exchange, it is cooled to 55°C (or to 50°C according to the subsequent process requirements). After entering the deethanizer tower for heat exchange, it is cooled to 50°C and enters the waste heat system from the waste heat medium inlet of the waste heat system.

[0091] The saturated steam at 105°C discharged from the high-temperature medium outlet of the secondary electric-driven heat pump enters the water vapor compressor. Through continuous compression and expansion processes, the pressure and temperature of the water vapor increase, thereby realizing energy conversion and work output, and the saturated steam at 130°C is discharged and enters the heat system for heating the reboiler.

[0092] In the second embodiment of the present application, the natural gas deep comprehensive utilization system includes:

[0093] Waste heat system; the waste heat system is provided with a waste heat medium outlet and a waste heat medium inlet;

[0094] A waste heat utilization system; the waste heat utilization system comprises a primary electric-driven heat pump, a secondary electric-driven heat pump, a first water vapor compressor and a second water vapor compressor;

[0095] A heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer;

[0096] Heat system;

[0097] The first-stage electric-driven heat pump is provided with a heat medium inlet, a high-temperature medium outlet, a waste heat medium inlet and a waste heat medium outlet; the waste heat medium inlet of the first-stage electric-driven heat pump is connected to the waste heat medium outlet of the waste heat system, and the high-temperature medium outlet of the first-stage electric-driven heat pump is connected to the cold medium inlet of the first water vapor compressor;

[0098] The secondary electric-driven heat pump is provided with a heat medium inlet, a high-temperature medium outlet, a waste heat medium inlet and a waste heat medium outlet; the waste heat medium inlet of the secondary electric-driven heat pump is connected to the waste heat medium outlet of the primary electric-driven heat pump, and the waste heat medium outlet of the secondary electric-driven heat pump is connected to the waste heat medium inlet of the deethanizer;

[0099] The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system;

[0100] The high-temperature medium inlet of the first water vapor compressor is connected to the high-temperature medium outlet of the first-stage electrically driven heat pump, and the high-temperature medium outlet of the first water vapor compressor is connected to the heat using system;

[0101] The high-temperature medium inlet of the second water vapor compressor is connected to the high-temperature medium outlet of the two-stage electrically driven heat pump, and the high-temperature medium outlet of the second water vapor compressor is connected to the heat using system.

[0102] Structure Figure 2 As shown, Figure 2 A diagram of a natural gas deep comprehensive utilization system provided in the second embodiment of the present invention, wherein 1 is a waste heat system, 2-1 is a primary electric-driven heat pump, 2-2 is a secondary electric-driven heat pump, 3-1 is a first water vapor compressor (water vapor compressor 1), 3-2 is a second water vapor compressor (water vapor compressor 2), 4 is a heat exchange auxiliary system, and 5 is a heat utilization system.

[0103] Figure 2 When the steam temperature generated by the two-stage electric-driven heat pump units cannot reach the temperature required by the process, they enter the corresponding water vapor compressor system and are raised to above 156°C for use in the heat system:

[0104] The 95°C waste hot water discharged from the waste heat medium outlet of the waste heat system is used as the waste heat source of the electric-driven heat pump unit. Specifically, the 95°C waste hot water discharged from the waste heat medium outlet of the waste heat system enters the first-stage electric-driven heat pump, and after heat exchange, saturated steam at 115°C is discharged and enters the first water vapor compressor (water vapor compressor 1). Through continuous compression and expansion processes, the pressure and temperature of the water vapor are increased, thereby realizing energy conversion and work output, and saturated steam at 156°C is discharged and enters the heat system for heating the reboiler;

[0105] The waste hot water discharged from the waste heat medium outlet of the first-stage electric-driven heat pump is cooled to 67°C and enters the second-stage electric-driven heat pump as the second-stage waste hot water. After heat exchange, it is cooled to 55°C (or to 50°C according to the subsequent process requirements). After entering the deethanizer tower for heat exchange, it is cooled to 50°C and enters the waste heat system from the waste heat medium inlet of the waste heat system.

[0106] The saturated steam at 105°C discharged from the high-temperature medium outlet of the secondary electric-driven heat pump enters the second water vapor compressor (water vapor compressor 2). Through continuous compression and expansion processes, the pressure and temperature of the water vapor are increased, thereby realizing energy conversion and work output, and the saturated steam at 156°C is discharged and enters the heat system for heating the reboiler.

[0107] In the third embodiment of the present application, the natural gas deep comprehensive utilization system includes:

[0108] Waste heat system; the waste heat system is provided with a waste heat medium outlet and a waste heat medium inlet;

[0109] Waste heat utilization system; the waste heat utilization system includes an electrically driven heat pump, a water vapor compressor, a low-pressure flash evaporator and a gas-liquid separator;

[0110] A heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer;

[0111] Heat system;

[0112] The low-pressure flash evaporator is provided with a waste heat medium inlet, a low-temperature steam outlet, a waste heat medium outlet and a reflux liquid inlet; the waste heat medium inlet of the low-pressure flash evaporator is connected to the waste heat medium outlet of the waste heat system, and the low-temperature steam outlet of the low-pressure flash evaporator is connected to the low-temperature steam inlet of the water vapor compressor;

[0113] The gas-liquid separator is provided with a heat medium inlet, a steam outlet and a reflux liquid outlet; the heat medium outlet of the water vapor compressor is connected to the heat medium inlet of the gas-liquid separator; the steam outlet of the gas-liquid separator is connected to the heat using system; the reflux liquid outlet of the gas-liquid separator is connected to the reflux liquid inlet of the low-pressure flash evaporator;

[0114] The electrically driven heat pump is provided with a first medium inlet, a second medium inlet, a first waste heat medium outlet and a second waste heat medium outlet; the first medium inlet and the second medium inlet of the electrically driven heat pump are both connected to the cold medium outlet of the low-pressure flash evaporator, the first waste heat medium outlet of the electrically driven heat pump is connected to the waste heat medium inlet of the low-pressure flash evaporator, and the second waste heat medium outlet of the electrically driven heat pump is connected to the waste heat medium inlet of the deethanizer;

[0115] The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system.

[0116] Structure Figure 3 As shown, Figure 3 A diagram of a natural gas deep comprehensive utilization system provided by the third embodiment of the present invention, wherein 1 is a waste heat system, 2 is a low-pressure flash evaporator, 3 is a water vapor compressor, 4 is a gas-liquid separator, 5 is an electrically driven heat pump, 6 is a heat exchange auxiliary system, and 7 is a heat utilization system.

[0117] Figure 3 In the process, the 95℃ waste water discharged from the waste heat medium outlet of the waste heat system enters the low-pressure flash evaporator to generate low-temperature steam, which enters the water vapor compressor. Through continuous compression and expansion processes, the pressure and temperature of the water vapor are increased, thereby realizing energy conversion and work output, providing high-temperature hot water or steam, and performing gas-liquid separation in the gas-liquid separator. The generated steam is used to heat the reboiler; the liquid after gas-liquid separation is recycled to the low-pressure flash evaporator;

[0118] The waste water after flashing in the low-pressure flash evaporator is 65℃ and enters the electric-driven heat pump. After heat exchange, it produces hot water or steam above 95℃ and is returned to the low-pressure flash evaporator.

[0119] The waste heat medium discharged from the electric-driven heat pump enters the deethanizer tower for heat exchange, is cooled to 50° C., and enters the waste heat system from the waste heat medium inlet of the waste heat system.

[0120] In a fourth embodiment of the present application, the natural gas deep comprehensive utilization system comprises:

[0121] Waste heat system; the waste heat system is provided with a waste heat medium outlet and a waste heat medium inlet;

[0122] LiBr module;

[0123] Waste heat utilization system; the waste heat utilization system includes a primary electric drive heat pump, a secondary electric drive heat pump and a water vapor compressor;

[0124] A heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer;

[0125] Heat system;

[0126] The lithium bromide module is provided with a waste heat medium inlet and a waste heat medium outlet; the waste heat medium inlet of the lithium bromide module is connected to the waste heat medium outlet of the waste heat system;

[0127] The first-stage electric-driven heat pump is provided with a heat medium inlet, a high-temperature medium outlet, a waste heat medium inlet and a waste heat medium outlet; the waste heat medium inlet of the first-stage electric-driven heat pump is connected to the waste heat medium outlet of the lithium bromide module, and the high-temperature medium outlet of the first-stage electric-driven heat pump is connected to the heat using system;

[0128] The secondary electric-driven heat pump is provided with a heat medium inlet, a high-temperature medium outlet, a waste heat medium inlet and a waste heat medium outlet; the waste heat medium inlet of the secondary electric-driven heat pump is connected to the waste heat medium outlet of the primary electric-driven heat pump, and the waste heat medium outlet of the secondary electric-driven heat pump is connected to the waste heat medium inlet of the deethanizer;

[0129] The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system;

[0130] The high-temperature medium inlet of the water vapor compressor is connected to the high-temperature medium outlet of the two-stage electrically driven heat pump, and the high-temperature medium outlet of the water vapor compressor is connected to the heat using system.

[0131] Structure Figure 4 As shown, Figure 4A diagram of a natural gas deep comprehensive utilization system provided in the fourth embodiment of the present invention, wherein 1 is a waste heat system, 2-1 is a primary electric-driven heat pump, 2-2 is a secondary electric-driven heat pump, 3 is a water vapor compressor, 4 is a heat exchange auxiliary system, 5 is a heat utilization system, and 6 is a lithium bromide module.

[0132] Figure 4 In the process, the 95°C waste hot water discharged from the waste heat medium outlet of the waste heat system is used as the waste heat source of the lithium bromide module. Specifically, the 95°C waste hot water discharged from the waste heat medium outlet of the waste heat system enters the lithium bromide module, and after heat exchange, the waste hot water with a waste heat of 87°C enters the first-stage electric drive heat pump;

[0133] The waste hot water discharged from the waste heat medium outlet of the first-stage electric-driven heat pump is cooled to 67°C and enters the second-stage electric-driven heat pump as the second-stage waste hot water. After heat exchange, it is cooled to 55°C (or to 50°C according to the subsequent process requirements). After entering the deethanizer tower for heat exchange, it is cooled to 50°C and enters the waste heat system from the cold medium inlet of the waste heat system.

[0134] The saturated steam at 105°C discharged from the high-temperature medium outlet of the secondary electric-driven heat pump enters the water vapor compressor. Through continuous compression and expansion processes, the pressure and temperature of the water vapor increase, thereby realizing energy conversion and work output, and the saturated steam at 130°C is discharged and enters the heat system for heating the reboiler.

[0135] Based on the fourth embodiment of the present application, the waste heat source of the waste heat system can also first enter the waste heat utilization system to be utilized to 65°C, and then enter the lithium bromide module for refrigeration; the waste heat source of the waste heat system can also simultaneously enter the lithium bromide unit to produce part of the cold water and the waste heat utilization system to produce the heating source.

[0136] Based on the fourth embodiment of the present application, the waste heat source provided by the waste heat system can also be used as the driving energy of the second-type lithium bromide absorption heat pump unit to generate steam below 0.8MPa, and then enter the waste heat utilization system; or the waste heat source provided by the waste heat system enters the second-type lithium bromide absorption heat pump unit and the waste heat utilization system at the same time.

[0137] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A system for comprehensive utilization of waste heat from deep processing of natural gas, characterized in that: include: Waste heat system; The waste heat system includes at least one of a mixed refrigerant device, a heat transfer oil fume device, a pretreatment device regenerator, and a high temperature stable light hydrocarbon device; A waste heat utilization system connected to a waste heat medium outlet of the waste heat system; A heat utilization system connected to the high-temperature medium outlet of the waste heat utilization system.

2. The system for comprehensive utilization of waste heat from deep processing of natural gas according to claim 1 is characterized in that: The waste heat utilization system includes at least one of an electrically driven heat pump unit, a water vapor compressor, a low-pressure flash evaporator and a gas-liquid separator; The heat utilizing system comprises at least one of a reboiler and a reaction tower.

3. The system for comprehensive utilization of waste heat from deep processing of natural gas according to claim 1 is characterized in that: The waste heat medium outlet of the waste heat utilization system is connected to the waste heat medium inlet of the waste heat system.

4. The system for comprehensive utilization of waste heat from deep processing of natural gas according to claim 1 is characterized in that: The natural gas deep comprehensive utilization system also includes an indirect heat exchange system; the high temperature medium inlet of the indirect heat exchange system is connected to the high temperature medium outlet of the waste heat utilization system, and the high temperature medium outlet of the indirect heat exchange system is connected to the high temperature medium inlet of the heat utilization system.

5. The system for comprehensive utilization of waste heat from deep processing of natural gas according to claim 1 is characterized in that: The natural gas deep comprehensive utilization system also includes a heat exchange auxiliary system; the waste heat medium inlet of the heat exchange auxiliary system is connected to the waste heat medium outlet of the waste heat utilization system, and the waste heat medium outlet of the heat exchange auxiliary system is connected to the waste heat medium inlet of the waste heat system.

6. The system for comprehensive utilization of waste heat from deep processing of natural gas according to claim 1, characterized in that: The natural gas deep comprehensive utilization system also includes a lithium bromide module; The waste heat medium inlet of the lithium bromide module is connected to the waste heat medium outlet of the waste heat system; The waste heat medium outlet of the lithium bromide module is connected to the waste heat medium inlet of the waste heat utilization system.

7. The system for comprehensive utilization of waste heat from deep processing of natural gas according to claim 1 is characterized in that: The waste heat utilization system includes a primary electric-driven heat pump, a secondary electric-driven heat pump and a water vapor compressor; The system for comprehensive utilization of waste heat from deep processing of natural gas also includes: a heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer; The waste heat medium inlet of the first-stage electric-driven heat pump is connected to the waste heat medium outlet of the waste heat system, and the high-temperature medium outlet of the first-stage electric-driven heat pump is connected to the heat-using system; The waste heat medium inlet of the secondary electric-driven heat pump is connected to the waste heat medium outlet of the primary electric-driven heat pump, and the waste heat medium outlet of the secondary electric-driven heat pump is connected to the waste heat medium inlet of the deethanizer; The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system; The high-temperature medium inlet of the water vapor compressor is connected to the high-temperature medium outlet of the two-stage electrically driven heat pump, and the high-temperature medium outlet of the water vapor compressor is connected to the heat using system.

8. The system for comprehensive utilization of waste heat from deep processing of natural gas according to claim 1 is characterized in that: The waste heat utilization system includes a primary electric-driven heat pump, a secondary electric-driven heat pump, a first water vapor compressor and a second water vapor compressor; The system for comprehensive utilization of waste heat from deep processing of natural gas also includes: a heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer; The waste heat medium inlet of the first-stage electric-driven heat pump is connected to the waste heat medium outlet of the waste heat system, and the high-temperature medium outlet of the first-stage electric-driven heat pump is connected to the cold medium inlet of the first water vapor compressor; The waste heat medium inlet of the secondary electric-driven heat pump is connected to the waste heat medium outlet of the primary electric-driven heat pump, and the waste heat medium outlet of the secondary electric-driven heat pump is connected to the waste heat medium inlet of the deethanizer; The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system; The high-temperature medium inlet of the first water vapor compressor is connected to the high-temperature medium outlet of the first-stage electrically driven heat pump, and the high-temperature medium outlet of the first water vapor compressor is connected to the heat using system; The high-temperature medium inlet of the second water vapor compressor is connected to the high-temperature medium outlet of the two-stage electrically driven heat pump, and the high-temperature medium outlet of the second water vapor compressor is connected to the heat using system.

9. The system for comprehensive utilization of waste heat from deep processing of natural gas according to claim 1, characterized in that: The waste heat utilization system includes an electrically driven heat pump, a water vapor compressor, a low-pressure flash evaporator and a gas-liquid separator; The system for comprehensive utilization of waste heat from deep processing of natural gas also includes: a heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer; The waste heat medium inlet of the low-pressure flash evaporator is connected to the waste heat medium outlet of the waste heat system, and the low-temperature steam outlet of the low-pressure flash evaporator is connected to the low-temperature steam inlet of the water vapor compressor; The heat medium outlet of the water vapor compressor is connected to the heat medium inlet of the gas-liquid separator; the steam outlet of the gas-liquid separator is connected to the heat using system; the reflux liquid outlet of the gas-liquid separator is connected to the reflux liquid inlet of the low-pressure flash evaporator; The first medium inlet and the second medium inlet of the electrically driven heat pump are both connected to the cold medium outlet of the low-pressure flash evaporator, the first waste heat medium outlet of the electrically driven heat pump is connected to the waste heat medium inlet of the low-pressure flash evaporator, and the second waste heat medium outlet of the electrically driven heat pump is connected to the waste heat medium inlet of the deethanizer; The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system.

10. The system for comprehensive utilization of waste heat from deep processing of natural gas according to claim 1, characterized in that: The waste heat utilization system includes a primary electric-driven heat pump, a secondary electric-driven heat pump and a water vapor compressor; The system for comprehensive utilization of waste heat from deep processing of natural gas also includes: a lithium bromide module and a heat exchange auxiliary system; the heat exchange auxiliary system is a deethanizer; The waste heat medium inlet of the lithium bromide module is connected to the waste heat medium outlet of the waste heat system; The waste heat medium inlet of the first-stage electric-driven heat pump is connected to the waste heat medium outlet of the lithium bromide module, and the high-temperature medium outlet of the first-stage electric-driven heat pump is connected to the heat-using system; The waste heat medium inlet of the secondary electric-driven heat pump is connected to the waste heat medium outlet of the primary electric-driven heat pump, and the waste heat medium outlet of the secondary electric-driven heat pump is connected to the waste heat medium inlet of the deethanizer; The waste heat medium outlet of the deethanizer is connected to the waste heat medium inlet of the waste heat system; The high-temperature medium inlet of the water vapor compressor is connected to the high-temperature medium outlet of the two-stage electrically driven heat pump, and the high-temperature medium outlet of the water vapor compressor is connected to the heat using system.

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