A multi-element refrigeration system device and system method capable of absorbing intermittent cooling

Abstract

The present invention provides a multi-component refrigeration system device and system method capable of absorbing intermittent cold. The multi-component refrigeration system device comprises a sequentially connected continuous step recovery module, a storage module and a continuous utilization module; the continuous step recovery module comprises at least two levels of recovery units, each recovery unit independently comprises a cold taking device, and the recovery units are sequentially connected from low to high levels through the cold taking device; the continuous utilization module comprises a temperature and pressure regulating device and a fourth cold taking device. The multi-component refrigeration system device realizes continuous step recovery of intermittent ship unloading cold, and further recovers and utilizes the cold source material itself as a refrigerant, providing cold energy for other devices in the chemical park, reducing coal consumption, and reducing high-grade energy consumption through comprehensive scheduling with high-temperature fluids in the chemical park and load regulation in coordination with refrigeration units, and has good industrial application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy recovery and utilization, and specifically relates to a multi-component refrigeration system device and a system method capable of absorbing intermittent cooling. Background Art

[0002] In recent years, domestic demand for LPG has increased rapidly, and the source of LPG in coastal economic open areas will mainly rely on imports. Imported LPG must rely on shipping loading and unloading terminals and corresponding underground storage. The storage of LPG in underground storage needs to meet the storage temperature requirements, so it is necessary to use heat media to increase the temperature. This process is often reheated through seawater, steam or circulating water, resulting in a waste of cooling capacity. Therefore, the rational use of the cooling capacity continuously supplied by liquefied petroleum gas and liquefied natural gas after unloading and storage is of great significance to energy conservation and emission reduction.

[0003] However, most of the research focuses on recycling the cold released by the continuous gasification of LPG as a raw material. There is still no good way to utilize the intermittent cold released by unloading due to its intermittent nature. Large chemical parks have a high demand for low-temperature chilled water, and the preparation of low-temperature chilled water generally uses electricity or steam as a high-grade energy source and is prepared by refrigeration units; lower-temperature refrigerants require electric refrigeration preparation, which consumes a lot of electricity, and the consumption of electricity and steam is fundamentally the consumption of coal.

[0004] At present, many researchers have studied cold energy storage, intermittent energy utilization and control methods, liquefied natural gas, liquefied petroleum gas cold energy recovery, etc. CN112325497A introduces a liquefied carbon dioxide energy storage system and its application, but the process is complicated and there are certain limitations on the temperature of recovered cold energy; CN110513932A discloses a ship-based LNG gasification and cold energy recovery heat exchange system and method, including an LNG fuel gasification unit, a circulating heat exchange network and two cold energy recovery units, and the LNG fuel gasification unit and the two cold energy recovery units are connected for heat exchange through a circulating heat exchange network; the circulating heat exchange network is an integrated composite circulating heat exchange device composed of a multi-channel liquid evaporator, a multi-channel steam superheater and a multi-channel subcooled steam reheater, which are packaged and integrated in the same multi-channel heat exchanger. Its cold energy recovery method is single and cannot realize resource utilization for other equipment in the industrial area. In addition, since the intermittent time of unloading is uncertain, and the unloading flow is usually large, and the instantaneous cold energy is large, how to reasonably utilize the intermittent unloading cold energy is a difficult problem that needs to be solved.

[0005] In summary, providing a method for recovering and storing cold energy from unloading LPG, including propane and butane, and continuously utilizing the cold energy has become an urgent problem to be solved. Summary of the invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide a multi-component refrigeration system device and system method that can absorb intermittent cold energy. The multi-component refrigeration system device recycles the cold energy from ship unloading in a step-by-step manner, providing cold energy at different temperature levels for other devices in the chemical park, thereby reducing coal consumption and high-grade energy consumption.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a multi-component refrigeration system device capable of absorbing intermittent cooling, the multi-component refrigeration system device comprising a continuous step recovery module, a storage module and a continuous utilization module connected in sequence;

[0009] The continuous step recovery module includes at least 2 levels of recovery units;

[0010] Each level of recovery unit independently includes a cooling device, and the recovery units are connected in sequence from low to high levels through the cooling device;

[0011] The continuous utilization module includes a temperature and pressure regulating device, a fourth cooling device, a third cooling user and a fourth user. The temperature and pressure regulating device, the fourth cooling device and the fourth user are connected in sequence, and the fourth cooling device and the third cooling user form a circular connection.

[0012] In the present invention, the multi-component refrigeration system device realizes the step-by-step recovery and utilization of cold energy by setting at least two levels of recovery units, and can provide cold energy of different temperature levels for different process devices, while solving the problems of uncertain unloading interval time and large instantaneous cold energy during unloading; the cold raw materials after step-by-step recovery can also be continuously supplied to the outside by utilizing their own characteristics, thereby further realizing the recovery and utilization of cold energy; the multi-component refrigeration system device has highly integrated energy, is energy-saving and efficient, and is in line with carbon emission reduction policies.

[0013] The following are preferred technical solutions of the present invention, but are not intended to be limitations of the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0014] As a preferred technical solution of the present invention, the continuous step recovery module includes a primary recovery unit.

[0015] Preferably, the primary recovery unit comprises a primary cold extraction device, a storage tank, a primary cold user and a turbine device which are connected in sequence.

[0016] Preferably, the primary cooling device is provided with a primary cooling source inlet, a primary cooling source outlet, a primary heating source inlet and a primary heating source outlet.

[0017] Preferably, the storage tank is connected to the primary heat source outlet of the primary cooling device.

[0018] Preferably, a branch pipeline is provided on the main pipeline at the inlet of the primary cold source.

[0019] Preferably, the branch pipe is connected to the turbine device.

[0020] As a preferred technical solution of the present invention, the continuous step recovery module includes a secondary recovery unit.

[0021] Preferably, the secondary recovery unit comprises a secondary cold extraction device, a refrigeration unit and a secondary cold user, and the secondary cold extraction device and the refrigeration unit are both connected to the secondary cold user.

[0022] Preferably, the other end of the secondary cold user is connected to the heat exchange unit and the refrigeration unit respectively.

[0023] Preferably, the secondary cooling device is provided with a secondary cooling source inlet, a secondary cooling source outlet, a secondary heating source inlet and a secondary heating source outlet.

[0024] Preferably, the secondary cold user is connected to the secondary heat source outlet of the secondary cold extraction device.

[0025] Preferably, the cold source outlet of the primary cooling device is connected to the cold source inlet of the secondary cooling device.

[0026] Preferably, the turbine device of the primary recovery unit is also connected to the refrigeration unit of the secondary recovery unit through a power generation device.

[0027] As a preferred technical solution of the present invention, the continuous step recovery module includes a three-stage recovery unit.

[0028] Preferably, the three-stage recovery unit includes a three-stage refrigeration device; the three-stage refrigeration device is cyclically connected with the refrigeration unit.

[0029] Preferably, the three-stage cooling device is provided with a three-stage cold source inlet, a three-stage cold source outlet, a three-stage heat source inlet and a three-stage heat source outlet.

[0030] Preferably, the cold source outlet of the secondary cooling device is connected to the cold source inlet of the tertiary cooling device.

[0031] Preferably, the third-stage heat source inlet of the three-stage cooling device is connected to the high-temperature circulating water outlet of the refrigeration unit.

[0032] Preferably, the third-stage heat source outlet of the three-stage cooling device is connected to the low-temperature circulating water inlet of the refrigeration unit.

[0033] Preferably, the high-temperature circulating water pipeline and the low-temperature circulating water pipeline are each independently provided with a storage tank, or the high-temperature circulating water pipeline and the low-temperature circulating water pipeline are jointly provided with one storage tank.

[0034] In the present invention, there can be one storage tank at this position to store both high-temperature and low-temperature water, using the difference in water density to perform stratified treatment of hot and cold water; or there can be two storage tanks to store water of different temperatures respectively.

[0035] As a preferred technical solution of the present invention, the fourth cooling device includes a fourth cold source inlet, a fourth cold source outlet, a fourth heat source inlet and a fourth heat source outlet.

[0036] Preferably, the temperature and pressure regulating device is connected to a fourth cold source inlet of the fourth cold taking device, and the fourth user is connected to a fourth cold source outlet of the fourth cold taking device.

[0037] Preferably, the fourth cold extraction device and the third cold user form a circulation through a fourth heat source inlet and a fourth heat source outlet.

[0038] Preferably, the temperature and pressure regulating device comprises a throttle valve.

[0039] In a second aspect, the present invention provides a method for stepwise recycling of intermittent cooling capacity, the method being performed using the multi-component refrigeration system device described in the first aspect, and the method comprising the following steps:

[0040] Continuous step recovery stage:

[0041] The high-temperature fluid and the cold source material enter the primary cooling device for primary heat exchange. The high-temperature fluid after the primary heat exchange is stored in the storage tank to provide continuous cooling for the primary cooling user. The high-temperature fluid after cooling is used to generate electricity through the turbine device.

[0042] After the primary heat exchange, the cold source material enters the secondary cold extraction device and performs secondary heat exchange with the refrigerant. The refrigerant after the secondary heat exchange and the refrigerant from the refrigeration unit jointly provide cooling capacity for the secondary cold users; part of the refrigerant after cooling returns to the refrigeration unit, and the other part enters the heat exchange unit for heat exchange;

[0043] After the secondary heat exchange, the cold source material enters the tertiary cooling device and performs a tertiary circulation heat exchange with the circulating water from the refrigeration unit;

[0044] The cold source material after three-stage heat exchange is stored in the storage module;

[0045] Continuous utilization stage:

[0046] The cold source material in the storage module enters the fourth cold extraction device after being cooled and decompressed, and provides coldness for the third cold user; the cold source material after cooling is provided for use by the fourth user.

[0047] In the present invention, first, the first-level cooling device exchanges heat by recycling the high-temperature fluid discharged from the park, and supplies it to the first-level cold users from the storage tank after liquefying it. The high-temperature and high-pressure gas after heat exchange and vaporization enters the turbine equipment to generate power; the second-level cooling device recovers part of the second-highest-grade cold, and supplies it to the second-level cold users together with the cold of the same grade prepared by the refrigeration unit, and its electric energy is supplied by the turbine power generation of the first-level cooling device; the third-level cooling device realizes the rewarming of the cold source to meet the storage temperature requirements, and the rewarmed circulating water is the outlet circulating water of the refrigeration unit driven by turbine electric energy; the fourth cooling device uses the cold source itself as a refrigerant for heat exchange after throttling expansion, and the prepared chilled water is supplied to the third cold user.

[0048] As a preferred technical solution of the present invention, the high-temperature fluid before the first-stage heat exchange is mixed with the high-temperature fluid after cooling and then passes through a turbine device to perform work and generate electricity.

[0049] In the present invention, two high-temperature fluids first enter the high-pressure stabilizing tank for pressure stabilization treatment.

[0050] Preferably, the high temperature fluid comprises high pressure process gas.

[0051] Preferably, the pressure of the high-pressure process gas is 5 to 80 barg, for example 5 barg, 10 barg, 20 barg, 30 barg, 40 barg, 50 barg, 60 barg, 70 barg or 80 barg, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] Preferably, the temperature of the high-pressure process gas is 50-150°C, for example, 50°C, 70°C, 90°C, 110°C, 130°C or 150°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0053] Preferably, the high-pressure process gas comprises carbon dioxide or ammonia.

[0054] In the present invention, during the process of primary recovery of cold energy, the high-pressure process gas liquefied by intermittent cold energy is continuously accumulated in the storage tank, thereby achieving continuity, and the cold energy recovery amount of the primary refrigeration device accounts for less than 30%.

[0055] Preferably, the cold source material includes any one of liquefied petroleum gas, propane or butane.

[0056] Preferably, the temperature of the cold source material is -50 to 0°C, for example, -50°C, -40°C, -30°C, -200°C, -10°C or 0°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0057] Preferably, the intermittent time for replenishing the cold source material is 0.5 to 7 days, for example 0.5 days, 1 days, 2 days, 3 days, 4 days, 5 days, 6 days or 7 days, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0058] As a preferred technical solution of the present invention, the refrigerant includes any one of ethylene glycol solution, Freon, ammonia, ethylene, propylene, methane, ethane or propane.

[0059] Preferably, the load proportion of the cooling capacity provided by the refrigeration unit is 25-100%, such as 25%, 50%, 75% or 95%, etc., and is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0060] In the present invention, the refrigerant entering the secondary cooling device is the same refrigerant as the refrigerant entering the refrigeration unit, and the continuous recovery of the cooling capacity in this process is achieved by adjusting the load of the refrigeration unit.

[0061] In the present invention, when the cold source material is in an intermittent period, the cooling capacity of the refrigerant is completely provided by the refrigeration unit. According to the specific temperature parameters, the refrigeration unit can be a lithium bromide unit or an electric refrigeration unit, and its electric energy can be completely or partially supplied by a turbine. When the cold source material is intermittent, the unit load can be further increased.

[0062] As a preferred technical solution of the present invention, the circulating water includes a high-temperature section and a low-temperature section.

[0063] Preferably, the circulating water temperature of the low temperature section is 20-32°C, for example, 20°C, 22°C, 24°C, 26°C, 28°C, 30°C or 32°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0064] Preferably, the circulating water temperature of the high temperature section is 25-42°C, for example, 25°C, 27°C, 30°C, 32°C, 35°C, 37°C, 40°C or 42°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0065] Preferably, the electric energy of the refrigeration unit is provided by a turbine device to generate electricity.

[0066] As a preferred technical solution of the present invention, the temperature of the cold source material in the storage module is 0-20°C, for example, 0°C, 5°C, 10°C, 15°C or 20°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0067] In the present invention, the storage temperature in the storage module is lower than the saturation temperature corresponding to the storage pressure. The system can realize continuous external supply through the storage module; the replenishment of raw materials before entering the storage module has a certain intermittent time, and the cold energy load in its entire temperature range reaches 10 to 250MW per hour, and the above process can recover part or all of the cold energy; if the temperature of the cold source material is still low after recovering part of the cold energy, external circulating water, steam or seawater is used to heat it up as a conventional re-temperature treatment method to meet the storage requirements.

[0068] Compared with the prior art, the present invention has the following beneficial effects:

[0069] (1) The multi-element refrigeration system device of the present invention realizes continuous step-by-step recovery of intermittent ship unloading cold energy by setting at least two levels of recovery units, providing cold energy at different temperature levels for different process devices in the chemical park, thereby solving the problem of uncertain intermittent ship unloading time and large instantaneous cold energy during ship unloading; the cold raw materials after step-by-step recovery can also be continuously supplied to the outside by utilizing their own characteristics, thereby further realizing the recovery and utilization of cold energy;

[0070] (2) The multi-component refrigeration system device of the present invention also reduces high-grade energy consumption through comprehensive scheduling of high-temperature fluids in chemical parks and load regulation of refrigeration units, is energy-efficient and highly economical, complies with carbon emission reduction policies, and has good industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 It is a schematic diagram of a process for performing step-by-step recovery and utilization of intermittent cooling capacity using a multi-component refrigeration system device provided in Example 1 of the present invention.

[0072] The direction of the arrow represents the direction of material or electrical energy flow. DETAILED DESCRIPTION

[0073] In order to better illustrate the present invention and facilitate understanding of the technical solution of the present invention, the present invention is further described in detail below. However, the following embodiments are only simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0074] The following are typical but non-limiting embodiments of the present invention:

[0075] Embodiment 1:

[0076] This embodiment provides a multi-component refrigeration system device and system method capable of absorbing intermittent cooling, wherein the multi-component refrigeration system device comprises a continuous step recovery module, a storage module and a continuous utilization module connected in sequence;

[0077] The continuous step recovery module includes three levels of recovery units;

[0078] The primary recovery unit includes a primary refrigeration device, a storage tank, a primary refrigeration user and a turbine device which are connected in sequence; the primary refrigeration device is provided with a primary cold source inlet, a primary cold source outlet, a primary heat source inlet and a primary heat source outlet; the storage tank is connected to the primary heat source outlet of the primary refrigeration device; a branch pipe is provided on the main pipe of the primary cold source inlet; the branch pipe is connected to the turbine device.

[0079] The secondary recovery unit includes a secondary cooling device, a refrigeration unit and a secondary cooling user, wherein the secondary cooling device and the refrigeration unit are both connected to the secondary cooling user; the other end of the secondary cooling user is respectively connected to the heat exchange unit and the refrigeration unit; the secondary cooling device is provided with a secondary cooling source inlet, a secondary cooling source outlet, a secondary heat source inlet and a secondary heat source outlet; the secondary cooling user is connected to the secondary heat source outlet of the secondary cooling device; the cooling source outlet of the primary cooling device is connected to the cooling source inlet of the secondary cooling device; the turbine device of the primary recovery unit is also connected to the refrigeration unit of the secondary recovery unit via a power generation device.

[0080] The three-stage recovery unit includes a three-stage cold-taking device; the three-stage cold-taking device is circularly connected with the refrigeration unit; the three-stage cold-taking device is provided with a three-stage cold source inlet, a three-stage cold source outlet, a three-stage heat source inlet and a three-stage heat source outlet; the cold source outlet of the two-stage cold-taking device is connected to the cold source inlet of the three-stage cold-taking device; the three-stage heat source inlet of the three-stage cold-taking device is connected to the high-temperature circulating water outlet of the refrigeration unit; the three-stage heat source outlet of the three-stage cold-taking device is connected to the low-temperature circulating water inlet of the refrigeration unit; a storage tank is jointly arranged on the high-temperature circulating water pipeline and the low-temperature circulating water pipeline.

[0081] The recovery unit is connected in sequence through a primary cooling device, a secondary cooling device and a tertiary cooling device;

[0082] The continuous utilization module includes a temperature and pressure regulating device, a fourth cooling device, a third cooling user and a fourth user. The temperature and pressure regulating device, the fourth cooling device and the fourth user are connected in sequence, and the fourth cooling device and the third cooling user form a circular connection.

[0083] The fourth cooling device includes a fourth cold source inlet, a fourth cold source outlet, a fourth heat source inlet and a fourth heat source outlet; the temperature and pressure regulating device is connected to the fourth cold source inlet of the fourth cooling device, and the fourth user is connected to the fourth cold source outlet of the fourth cooling device; the fourth cooling device and the third cold user form a circulation through the fourth heat source inlet and the fourth heat source outlet; the temperature and pressure regulating device is a throttle valve.

[0084] The schematic diagram of the process of step-by-step recovery and utilization of intermittent cooling capacity using the above multi-component refrigeration system is as follows: Figure 1 As shown, the method for stepwise recycling of intermittent cooling capacity comprises the following steps:

[0085] It is stipulated that the propane purchase volume of a chemical park is 1.5 million tons / year, and the propane is unloaded at the shipping terminal. The storage and transportation pressure is normal pressure and the temperature is -45°C. The liquid propane is pressurized to 12 barG by a high-pressure pump during unloading, and the flow rate is 500t / h.

[0086] After pressure adjustment, the 120℃, 24barg carbon dioxide enters the primary refrigeration device with propane for primary heat exchange. After the primary heat exchange, the carbon dioxide becomes liquid and is stored in a storage tank to provide continuous cooling capacity for primary refrigeration users. The heated gas phase carbon dioxide after cooling is used to generate electricity through a turbine device.

[0087] After the primary heat exchange, the propane enters the secondary cooling device and performs secondary heat exchange with the Freon. The Freon after the secondary heat exchange and the Freon from the refrigeration unit (load is 50%) jointly provide cooling capacity for the secondary cooling users; part of the Freon after cooling enters the heat exchange unit for heat exchange, and the other part returns to the refrigeration unit;

[0088] After the secondary heat exchange, the propane enters the tertiary cooling device and performs a tertiary circulation heat exchange with the circulating water from the refrigeration unit. The temperature of the high temperature section is 38°C and the temperature of the low temperature section is 27°C.

[0089] The 3°C propane after three-stage heat exchange is stored in the storage module;

[0090] The propane in the storage module enters the fourth cooling device after being cooled and decompressed, and provides cooling capacity for the third cooling user. The propane after cooling can be used as a chemical raw material at a supply rate of 60t / h.

[0091] The cooling recovery efficiency and economic efficiency of this embodiment are calculated over a period of one year.

[0092] Due to the large demand for cooling capacity in the park's storage and transportation tank area and the main device area, in order to meet the demand, the main device is cooled by refrigeration units (steam lithium bromide units and ethylene glycol, Freon electric refrigeration), supplemented by propane recovery cooling, which is used for process reaction heat removal, electricity consumption and steam consumption.

[0093] In the above embodiment, during the ship unloading period, the theoretical total refrigeration load per hour for ship unloading is 17.9 MW.

[0094] In fact, through primary and secondary recovery, 10.3MW of propane cooling capacity can be recovered, and the propane temperature can be raised to -17℃. Then, 7.6MW of cooling capacity can be further recovered through the circulating water of the refrigeration unit. The energy saving of circulating water cooling capacity recovery is reflected in the reduction of cooling tower fan consumption and the reduction of water replenishment. When the unloading cooling capacity is intermittent, the propane heat exchange cooling capacity is 0MW, and the load of the variable frequency refrigeration unit is increased to 100%. At this time, the cooling capacity is completely provided by the refrigeration unit.

[0095] Through calculation, it can be known that the first and second level cooling capacity (originally required to be provided by refrigeration units) is recovered by 10.3MW. Compared with the complete use of electric refrigeration units, it can save about 2000kWh of electricity. Based on the current operating conditions of 3000h of annual ship unloading, the economic benefit is 8.96 million yuan / year, with significant energy-saving effect.

[0096] Embodiment 2:

[0097] The present embodiment provides a multi-component refrigeration system device and system method that can absorb intermittent cooling. The multi-component refrigeration system device refers to the multi-component refrigeration system device in Example 1, with the difference that: the continuous step recovery module includes 2 levels of recovery units, that is, only a secondary recovery unit and a tertiary recovery unit, but no primary recovery unit, so the parts related to the primary recovery unit are deleted accordingly.

[0098] The method for stepwise recovery and utilization of intermittent cooling capacity using the above-mentioned multi-component refrigeration system device comprises the following steps:

[0099] It is stipulated that the butane purchase volume of a certain chemical park is 1 million tons / year, and butane is unloaded through the shipping terminal, with storage and transportation pressure at normal pressure and temperature of -5°C. A high-pressure pump is used to pressurize the propane to 5 barg for unloading, with a flow rate of 500t / h. It enters the secondary cooling device and undergoes secondary heat exchange with an ethylene glycol solution with a volume concentration of 28%. The ethylene glycol solution after the secondary heat exchange and the ethylene glycol solution from the refrigeration unit (with a load of 50%) jointly provide cooling for the secondary cooling users; a part of the ethylene glycol solution after cooling enters the heat exchange unit for heat exchange, and the other part returns to the refrigeration unit;

[0100] After the secondary heat exchange, the ethylene glycol solution enters the tertiary cooling device and performs a tertiary circulation heat exchange with the circulating water from the refrigeration unit. The temperature of the high temperature section is 38°C and the temperature of the low temperature section is 27°C.

[0101] The propane at 16°C after three-stage heat exchange is stored in the storage module;

[0102] The butane in the storage module enters the fourth cooling device after being cooled and decompressed, and provides cooling capacity for the third cooling user; the propane after cooling can be used as a chemical raw material at a supply rate of 270t / h.

[0103] The cooling recovery efficiency and economic efficiency of this embodiment are calculated over a period of one year.

[0104] Due to the large demand for cooling capacity in the park's storage and transportation tank area and main device area, in order to meet the demand, the main device uses the refrigeration unit steam lithium bromide unit to prepare 1-7°C cold water, and uses electric refrigeration to prepare circulating refrigerant below 0°C, supplemented by propane recovery cooling, which is used for process reaction heat removal, saving electricity and steam consumption.

[0105] In the above embodiment, the theoretical total refrigeration load per hour of ship unloading is 9.3MW.

[0106] In fact, through secondary recovery, 3.6MW of butane cooling capacity can be recovered, which can reduce the temperature of the ethylene glycol refrigeration unit from 10℃ to 1℃, raise the temperature of butane to 5℃, and then cool it through the circulating water of the refrigeration unit, which can further recover 7.6MW of cooling capacity. The main energy consumption saved in this part is the power consumption of the cooling tower fan and water consumption. When the unloading cooling capacity is intermittent, the butane heat exchange cooling capacity is 0MW, and the refrigeration unit load is increased to 100%. At this time, the cooling capacity is completely provided by the refrigeration unit.

[0107] Calculations show that compared with using only ethylene glycol electric refrigeration units, it can save about 720kWh of electricity, unload the ship for 2000h, and generate an economic benefit of 810,000 yuan per year.

[0108] Comparative Example 1:

[0109] This comparative example provides a refrigeration system device and system method that can absorb intermittent cooling. The multi-component refrigeration system device refers to the system in Example 1, with the only difference being that it does not include a primary recovery unit and a secondary recovery unit.

[0110] The operation method comprises the following steps: 500 t / h propane is directly reheated to 3° C. through circulating water heat exchange and then stored in a storage module;

[0111] The propane in the storage module enters the fourth cooling device after being cooled and decompressed, and provides cooling capacity for the third cooling user; the propane after cooling can be used as a chemical raw material at a supply rate of 60t / h.

[0112] Calculate the cooling recovery efficiency and economy of this comparison ratio over a period of one year.

[0113] Due to the large demand for cooling capacity in the park's storage and transportation tank area and the main device area, in order to meet the demand, the main device is cooled by refrigeration units (steam lithium bromide units and ethylene glycol, Freon units) to remove heat from process reactions, electricity consumption and steam consumption.

[0114] In the above comparison, the theoretical annual total refrigeration load for ship unloading is 17.9MW.

[0115] In fact, through the primary and secondary recovery, 10.3MW of propane cooling capacity can be recovered, making propane. When the cooling capacity of unloading is intermittent, the propane heat exchange cooling capacity is 0MW, and the load of the variable frequency refrigeration unit is increased to 100%. At this time, the cooling capacity is completely provided by the refrigeration unit. If only the third-level recovery or the supporting circulating water tower cooling is used, 135kWh of electricity can be saved, and the benefit is about 600,000 yuan / year, and the energy saving effect is average.

[0116] Calculations show that compared with full-circulation water cooling, primary, secondary and tertiary cooling recovery can save about 1,865 kWh of electricity, with an economic benefit of 8.36 million yuan per year, and the energy-saving effect is significant.

[0117] It can be seen from the above embodiments and comparative examples that the multi-component refrigeration system device of the present invention realizes the step-by-step recovery and utilization of cold energy by setting at least 2 levels of recovery units, and can provide cold energy of different temperature levels for different process devices, while solving the problems of uncertain unloading interval time and large instantaneous cold energy during unloading; the cold raw materials after step-by-step recovery can also use their own characteristics to be continuously supplied to the outside, thereby further realizing the recovery and utilization of cold energy; the multi-component refrigeration system device has highly integrated energy, is energy-saving and efficient, has high economic benefits, and is in line with carbon emission reduction policies.

[0118] The applicant declares that the present invention illustrates the system and detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned system and detailed method, that is, it does not mean that the present invention must rely on the above-mentioned system and detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the operation of the present invention, addition of auxiliary operations, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A multi-component refrigeration system device capable of absorbing intermittent cooling, characterized in that: The multi-component refrigeration system device comprises a continuous step recovery module, a storage module and a continuous utilization module connected in sequence; The continuous step recovery module includes a primary recovery unit, a secondary recovery unit and a tertiary recovery unit; The primary recovery unit includes a primary cold extraction device, a storage tank, a primary cold user and a turbine device connected in sequence; The secondary recovery unit includes a secondary cold extraction device, a refrigeration unit and a secondary cold user; The three-stage recovery unit includes a three-stage cooling device; Each level of recovery unit independently includes a cooling device, and the recovery units are connected in sequence from low to high levels through the cooling device; The continuous utilization module includes a temperature and pressure regulating device, a fourth cooling device, a third cooling user and a fourth user. The temperature and pressure regulating device, the fourth cooling device and the fourth user are connected in sequence, and the fourth cooling device and the third cooling user form a circular connection.

2. The multi-component refrigeration system device according to claim 1, characterized in that: The primary cooling device is provided with a primary cooling source inlet, a primary cooling source outlet, a primary heating source inlet and a primary heating source outlet.

3. The multi-component refrigeration system device according to claim 2, characterized in that: The storage tank is connected to the primary heat source outlet of the primary cooling device.

4. The multi-component refrigeration system device according to claim 2, characterized in that: A branch pipeline is arranged on the main pipeline at the inlet of the primary cold source.

5. The multi-component refrigeration system device according to claim 4, characterized in that: The branch pipeline is connected to the turbine device.

6. The multi-component refrigeration system device according to claim 1, characterized in that: The secondary cold extraction device and the refrigeration unit are both connected to the secondary cold user.

7. The multi-component refrigeration system device according to claim 1, characterized in that: The other end of the secondary cold user is connected to the heat exchange unit and the refrigeration unit respectively.

8. The multi-component refrigeration system device according to claim 1, characterized in that: The secondary cooling device is provided with a secondary cooling source inlet, a secondary cooling source outlet, a secondary heating source inlet and a secondary heating source outlet.

9. The multi-component refrigeration system device according to claim 8, characterized in that: The secondary cold user is connected to the secondary heat source outlet of the secondary cold extraction device.

10. The multi-component refrigeration system device according to claim 1, characterized in that: The cold source outlet of the primary cooling device is connected to the cold source inlet of the secondary cooling device.

11. The multi-component refrigeration system device according to claim 1, characterized in that: The turbine device of the primary recovery unit is also connected to the refrigeration unit of the secondary recovery unit through a power generation device.

12. The multi-component refrigeration system device according to claim 1, characterized in that: The three-stage cooling device is connected to the refrigeration unit in a circulation manner.

13. The multi-component refrigeration system device according to claim 1, characterized in that: The three-stage cooling device is provided with a three-stage cold source inlet, a three-stage cold source outlet, a three-stage heat source inlet and a three-stage heat source outlet.

14. The multi-component refrigeration system device according to claim 1, characterized in that: The cold source outlet of the secondary cooling device is connected to the cold source inlet of the tertiary cooling device.

15. The multi-component refrigeration system device according to claim 1, characterized in that: The third-stage heat source inlet of the three-stage cooling device is connected to the high-temperature circulating water outlet of the refrigeration unit.

16. The multi-component refrigeration system device according to claim 1, characterized in that: The third-stage heat source outlet of the three-stage cooling device is connected to the low-temperature circulating water inlet of the refrigeration unit.

17. The multi-component refrigeration system device according to claim 15 or 16, characterized in that: The high-temperature circulating water pipeline and the low-temperature circulating water pipeline are each independently provided with a storage tank, or the high-temperature circulating water pipeline and the low-temperature circulating water pipeline are jointly provided with a storage tank.

18. The multi-component refrigeration system device according to claim 1, characterized in that: The fourth cooling device includes a fourth cooling source inlet, a fourth cooling source outlet, a fourth heating source inlet and a fourth heating source outlet.

19. The multi-component refrigeration system device according to claim 18, characterized in that: The temperature and pressure regulating device is connected to the fourth cold source inlet of the fourth cold taking device, and the fourth user is connected to the fourth cold source outlet of the fourth cold taking device.

20. The multi-component refrigeration system device according to claim 18, characterized in that: The fourth cold extraction device and the third cold user form a circulation through a fourth heat source inlet and a fourth heat source outlet.

21. The multi-component refrigeration system device according to claim 1, characterized in that: The temperature and pressure regulating device includes a throttle valve.

22. A method for stepwise recycling of intermittent cooling, characterized in that: The method is performed using a multi-component refrigeration system device according to any one of claims 1 to 21, and the method comprises the following steps: Continuous step recovery stage: The high-temperature fluid and the cold source material enter the primary cooling device for primary heat exchange. The high-temperature fluid after the primary heat exchange is stored in the storage tank to provide continuous cooling for the primary cooling user. The high-temperature fluid after cooling is used to generate electricity through the turbine device. The high-temperature fluid includes a high-pressure process gas; the pressure of the high-pressure process gas is 5-80 barg; the temperature of the high-pressure process gas is 50-150° C.; the high-pressure process gas includes carbon dioxide or ammonia; After the primary heat exchange, the cold source material enters the secondary cold extraction device and performs secondary heat exchange with the refrigerant. The refrigerant after the secondary heat exchange and the refrigerant from the refrigeration unit jointly provide cooling capacity for the secondary cold users; part of the refrigerant after cooling returns to the refrigeration unit, and the other part enters the heat exchange unit for heat exchange; After the secondary heat exchange, the cold source material enters the tertiary cooling device and performs a tertiary circulation heat exchange with the circulating water from the refrigeration unit; The cold source material after three-stage heat exchange is stored in the storage module; Continuous utilization stage: The cold source material in the storage module enters the fourth cold extraction device after being cooled and decompressed, and provides coldness for the third cold user; the cold source material after cooling is provided for use by the fourth user.

23. The method according to claim 22, characterized in that The high-temperature fluid before the first-stage heat exchange is mixed with the high-temperature fluid after cooling and then passes through a turbine device to generate electricity.

24. The method according to claim 22, characterized in that The cold source material includes any one of liquefied petroleum gas, propane or butane.

25. The method according to claim 22, characterized in that The temperature of the cold source material is -50~0℃.

26. The method according to claim 22, characterized in that The intermittent time for replenishing the cold source material is 0.5~7d.

27. The method according to claim 22, characterized in that The refrigerant includes any one of ethylene glycol solution, Freon, ammonia, ethylene, propylene, methane, ethane or propane.

28. The method according to claim 22, characterized in that The refrigeration unit provides cooling capacity at a load ratio of 25% to 100%.

29. The method according to claim 22, characterized in that The circulating water includes a high temperature section and a low temperature section; The circulating water temperature of the low temperature section is 20-32°C; the circulating water temperature of the high temperature section is 25-42°C.

30. The method according to claim 23, characterized in that The electric energy of the refrigeration unit is provided by the turbine device for generating electricity.

31. The method according to claim 22, characterized in that The temperature of the cold source material in the storage module is 0-20°C.

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