Organic rankine cycle waste heat recovery and ultra-low temperature freezing coupled system and control method

Abstract

The application discloses an organic Rankine cycle waste heat recovery and ultralow-temperature freezing coupling system and a control method, the system comprises an internal combustion engine waste heat recovery system, an organic Rankine cycle system and an ultralow-temperature freezing system; the application provides power for ship electric equipment through waste heat power generation, reduces the consumption of power generation fuel, meanwhile, the ultralow-temperature freezing system can realize ultralow-temperature freezing of various fishes during ocean fishing of a fishing boat, and the ultralow-temperature freezing system of the application adopts a water-cooled condenser to replace a traditional natural convection heat exchange type condenser; compared with the traditional convection heat exchange type condenser, the ultralow-temperature freezing system has a greatly improved energy efficiency ratio; in addition, the internal combustion engine cylinder liner water auxiliary condenser, the organic Rankine cycle system condenser and the ultralow-temperature freezing system condenser are coupled into a heat exchange system in a series mode along the flowing direction of cooling water, through step-by-step utilization of energy, the heat exchange performance of the whole system is improved, and the size of the heat exchange system is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy-saving technology, in particular to an organic Rankine cycle waste heat recovery and ultra-low temperature freezing coupled system and control method. BACKGROUND

[0002] Energy refers to resources that can provide energy, and the energy here usually refers to heat energy, electric energy, light energy, mechanical energy, chemical energy, etc., which can provide kinetic energy, mechanical energy and energy for human beings, and while actively developing new energy, more and more attention is paid to recycling and utilizing waste heat resources, and efficient utilization of waste heat resources is also an effective way to solve energy shortage.

[0003] At present, by evaluating the indexes of existing large and medium-sized fishing and cargo ship diesel engines, only 30% to 40% of the energy is output as power, and the other energy is discharged into the atmosphere in the form of waste heat, which not only causes a large amount of energy waste, but also pollutes the environment;

[0004] Secondly, there are a large number of electrical equipment in the running process of the ship, and these electrical equipment all adopt diesel generators to generate electricity, and the efficiency of the diesel generator is generally about 30%, the power generation efficiency is low, the fuel consumption for power generation is large, and it is not conducive to energy saving and emission reduction;

[0005] At the same time, the fishing boat needs to freeze various fish at ultra-low temperature during the process of ocean fishing to maximize the freshness of various fish, so as to ensure the economic income of fishermen, and further increase the energy consumption, so it is urgent to solve the problem of energy saving and emission reduction of ship energy, therefore, the present application provides an organic Rankine cycle waste heat recovery and ultra-low temperature freezing coupled system and control method to solve the problems in the prior art. SUMMARY

[0006] In view of the above problems, the present application aims to provide an organic Rankine cycle waste heat recovery and ultra-low temperature freezing coupled system and control method, which organically combines internal combustion engine clean combustion technology, organic Rankine cycle waste heat recovery technology, ultra-low temperature refrigeration technology, heat exchange technology and automatic control technology, realizes efficient and stable operation of the system, and solves the problem of energy saving and emission reduction of ship energy.

[0007] In order to achieve the purpose of the present application, the present application realizes the technical scheme that the organic Rankine cycle waste heat recovery and ultra-low temperature refrigeration coupled system comprises an internal combustion engine waste heat recovery system, an organic Rankine cycle system and an ultra-low temperature refrigeration system, the internal combustion engine waste heat recovery system comprises an internal combustion engine body, a cylinder liner water heat exchanger, a flue gas heat exchanger, a waste heat recovery heat exchanger, a water pump and a series composite heat exchange system, the cylinder liner water heat exchanger is installed on the internal combustion engine body, the internal combustion engine body and the cylinder liner water heat exchanger are connected with the flue gas heat exchanger, the waste heat recovery heat exchanger is connected with the series composite heat exchange system through the water pump, and the organic Rankine cycle system is coupled with the organic Rankine cycle system through the waste heat recovery heat exchanger.

[0008] The organic Rankine cycle system comprises an expander, a series composite heat exchange system, a liquid storage tank, a working medium pump and a waste heat recovery heat exchanger, the expander is connected with a generator through a mechanical transmission mechanism, the series composite heat exchange system is connected with the working medium pump through the liquid storage tank, the working medium pump is connected with the expander through the waste heat recovery heat exchanger, and the expander is connected with the series composite heat exchange system.

[0009] The ultra-low temperature refrigeration system comprises a high-temperature refrigeration cycle system and a low-temperature refrigeration cycle system, and the high-temperature refrigeration cycle system is coupled with the low-temperature refrigeration cycle system through a condenser evaporator.

[0010] Further improvement lies in that the high-temperature refrigeration cycle system comprises a high-temperature compressor, a series composite heat exchange system, a high-temperature expansion valve and a condenser evaporator which are connected in sequence through pipelines, and the low-temperature refrigeration cycle system comprises a low-temperature compressor, a condenser evaporator, a low-temperature expansion valve and an ultra-low temperature system evaporator which are connected in sequence through pipelines.

[0011] Further improvement lies in that the internal combustion engine waste heat recovery system and the organic Rankine cycle system are coupled with the ultra-low temperature refrigeration system through the series composite heat exchange system, and the series composite heat exchange system is coupled in a series mode along the cooling water flow direction and comprises an ultra-low temperature refrigeration system condenser, an organic Rankine cycle system condenser and an internal combustion engine cylinder liner water auxiliary condenser.

[0012] Further improvement lies in that the loop inlet and outlet of the ultra-low temperature refrigeration system condenser are connected with the high-temperature compressor and the high-temperature expansion valve respectively, the backflow inlet and outlet of the organic Rankine cycle system condenser are connected with the expander and the liquid storage tank respectively, and the backflow inlet and outlet of the internal combustion engine cylinder liner water auxiliary condenser are connected with the water pump and the cylinder liner water heat exchanger respectively.

[0013] Further improvement lies in that the ultra-low temperature refrigeration system condenser, the organic Rankine cycle system condenser and the internal combustion engine cylinder liner water assisted condenser are arranged in sequence according to the heat exchange temperature, the heat exchange temperature of the organic Rankine cycle system condenser is greater than that of the ultra-low temperature refrigeration system condenser and less than that of the internal combustion engine cylinder liner water assisted condenser.

[0014] Further improvement lies in that the seawater inlet of the ultra-low temperature refrigeration system condenser is provided with a first inlet pipeline and a second inlet pipeline, the seawater outlet of the ultra-low temperature refrigeration system condenser is connected with a first outlet pipeline through a first electric control adjusting valve, the first inlet pipeline is connected with the seawater inlet of the ultra-low temperature refrigeration system condenser, and the second inlet pipeline is connected with the first outlet pipeline through a second electric control adjusting valve.

[0015] Further improvement lies in that the first outlet pipeline is connected with the seawater inlet of the organic Rankine cycle system condenser through a third electric control adjusting valve, the seawater outlet of the organic Rankine cycle system condenser is connected with a second outlet pipeline, the first outlet pipeline is connected with the second outlet pipeline through a fourth electric control adjusting valve, the second outlet pipeline is connected with the seawater outlet of the internal combustion engine cylinder liner water assisted condenser through a fifth electric control adjusting valve, and the second outlet pipeline is connected with the seawater inlet of the internal combustion engine cylinder liner water assisted condenser through a sixth electric control adjusting valve.

[0016] The control method of the organic Rankine cycle waste heat recovery and ultra-low temperature refrigeration coupled system comprises the following steps.

[0017] Step one: the cylinder liner water waste heat generated by the operation of the internal combustion engine body is heat exchanged with circulating cooling water through a cylinder liner water heat exchanger, the heated circulating cooling water further increases the temperature after absorbing the flue gas waste heat generated by the operation of the internal combustion engine body through a flue gas heat exchanger, then the high-temperature cooling water enters a waste heat recovery heat exchanger and is heat exchanged with high-pressure low-temperature liquid organic working medium from the outlet of a working medium pump, the high-pressure low-temperature liquid organic working medium is heated in the waste heat recovery heat exchanger and becomes high-temperature high-pressure gaseous organic working medium, the high-temperature cooling water is cooled after heat release and is pressurized by a water pump and then enters a series composite heat exchange system for further cooling, and the cooling water enters the cylinder liner water heat exchanger again after being cooled to a set temperature, forming a waste heat recovery cycle of the internal combustion engine body, wherein the high-temperature flue gas generated by the internal combustion engine body is directly discharged into the atmosphere after heat release in the flue gas heat exchanger.

[0018] Step two: the low-temperature liquid organic working medium at the outlet of the liquid storage tank enters the working medium pump, is compressed into high-pressure low-temperature liquid organic working medium, and then enters the waste heat recovery heat exchanger to exchange heat with the high-temperature cooling water from the flue gas heat exchanger; the high-pressure low-temperature liquid organic working medium is heated and then becomes high-temperature high-pressure gaseous organic working medium, which enters the expander to do work and then becomes low-temperature low-pressure gaseous organic working medium, which enters the series compound heat exchange system to be cooled and heated to become low-temperature low-pressure liquid organic working medium and then enters the liquid storage tank, forming an organic Rankine cycle, wherein the expander drives the generator to generate electricity to power the electric equipment in the ultra-low-temperature freezing system;

[0019] Step three: the high-temperature high-pressure gaseous refrigerant at the outlet of the high-temperature compressor enters the series compound heat exchange system, is condensed into high-temperature liquid refrigerant, enters the high-temperature expansion valve to be throttled into low-temperature low-pressure gas-liquid two-phase refrigerant, and then enters the condenser evaporator to exchange heat with the high-temperature high-pressure refrigerant at the outlet of the low-temperature compressor, becomes low-temperature low-pressure gaseous refrigerant, and then enters the high-temperature compressor, forming a high-temperature refrigeration cycle;

[0020] Step four: the high-temperature high-pressure gaseous refrigerant at the outlet of the low-temperature compressor enters the condenser evaporator, exchanges heat with the low-temperature low-pressure gas-liquid two-phase refrigerant at the outlet of the high-temperature expansion valve, is condensed into high-temperature high-pressure liquid refrigerant, enters the low-temperature expansion valve to be throttled into low-temperature low-pressure gas-liquid two-phase refrigerant, and then enters the ultra-low-temperature freezing system evaporator to become low-temperature low-pressure gaseous refrigerant, which enters the low-temperature compressor, forming a low-temperature refrigeration cycle.

[0021] The internal combustion engine waste heat recovery system, the organic Rankine cycle system and the ultra-low-temperature freezing system are coupled, electricity is generated by the waste heat to provide power for the electric equipment of the ship, the consumption of the fuel for power generation is reduced, and the ultra-low-temperature freezing system can realize the ultra-low-temperature freezing of various fishes during the fishing process of the fishing boat, so that the freshness of the fishes is maximally guaranteed.

[0022] The water-cooled condenser is used in the ultra-low-temperature freezing system to replace the traditional natural convection heat exchange type condenser; compared with the traditional convection heat exchange type condenser, on the one hand, the condensing temperature of the ultra-low-temperature freezing system is greatly reduced due to the low and stable temperature of seawater during the summer operation, and on the other hand, the heat exchange coefficient of the condensing side of the system is greatly improved, so that the energy efficiency ratio of the ultra-low-temperature freezing system is greatly improved.

[0023] In addition, the application adopts a series composite heat exchange system, which couples the cylinder liner water auxiliary condenser, the organic Rankine cycle system condenser and the ultra-low temperature freezing system condenser in series along the flow direction of cooling water to form a heat exchange system, and the three condensers are arranged in order according to the heat exchange temperature. The series composite heat exchange system improves the heat exchange performance of the whole system and greatly reduces the size of the heat exchange system through the cascade utilization of energy, and is more convenient to install in the case of limited space in the ship cabin. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings described below only show some embodiments of the present application, and all other drawings obtained by those skilled in the art without creative labor based on these drawings also belong to the protection scope of the present application.

[0025] Figure 1 is a schematic diagram of the system connection structure of the present application;

[0026] Figure 2 is a schematic diagram of the series composite heat exchange system connection structure of the device of the present application.

[0027] 1, internal combustion engine body; 2, cylinder liner water heat exchanger; 3, flue gas heat exchanger; 4, waste heat recovery heat exchanger; 5, water pump; 6, series composite heat exchange system; 7, expander; 8, liquid storage tank; 9, working medium pump; 10, generator; 11, condenser evaporator; 12, high-temperature compressor; 13, high-temperature expansion valve; 14, low-temperature compressor; 15, low-temperature expansion valve; 16, ultra-low temperature system evaporator; 601, ultra-low temperature freezing system condenser; 602, organic Rankine cycle system condenser; 603, internal combustion engine cylinder liner water auxiliary condenser; 604, first inlet pipeline; 605, second inlet pipeline; 606, first electric control regulating valve; 607, first outlet pipeline; 608, second electric control regulating valve; 609, third electric control regulating valve; 610, second outlet pipeline; 611, fourth electric control regulating valve; 612, fifth electric control regulating valve; 613, sixth electric control regulating valve. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor also belong to the protection scope of the present application.

[0029] Embodiment one

[0030] Referring to Figure 1 , Figure 2 The embodiment provides an organic Rankine cycle waste heat recovery and ultra-low temperature refrigeration coupling system, which comprises an internal combustion engine waste heat recovery system, an organic Rankine cycle system and an ultra-low temperature refrigeration system. The internal combustion engine waste heat recovery system comprises an internal combustion engine body 1, a cylinder liner water heat exchanger 2, a flue gas heat exchanger 3, a waste heat recovery heat exchanger 4, a water pump 5 and a series composite heat exchange system 6 which are sequentially connected through pipelines. The cylinder liner water heat exchanger 2 is installed on the internal combustion engine body 1, and the internal combustion engine body 1 and the cylinder liner water heat exchanger 2 are connected with the flue gas heat exchanger 3. The waste heat recovery heat exchanger 4 is connected with the series composite heat exchange system 6 through the water pump 5. The organic Rankine cycle system is coupled with the organic Rankine cycle system through the waste heat recovery heat exchanger 4, so as to form an organic Rankine cycle power generation system based on internal combustion engine waste heat utilization, and realize recovery and utilization of the internal combustion engine waste heat.

[0031] The organic Rankine cycle system comprises an expander 7, the series composite heat exchange system 6, a liquid storage tank 8, a working medium pump 9 and the waste heat recovery heat exchanger 4 which are sequentially connected through pipelines. The expander 7 is connected with a generator 10 through a mechanical transmission mechanism, so as to convert the expansion work output by the organic Rankine cycle system into electric energy to provide electric energy for shipboard electric equipment. The series composite heat exchange system 6 is connected with the working medium pump 9 through the liquid storage tank 8. The working medium pump 9 is connected with the expander 7 through the waste heat recovery heat exchanger 4. The expander 7 is connected with the series composite heat exchange system 6.

[0032] The ultra-low temperature refrigeration system comprises a high-temperature refrigeration cycle system and a low-temperature refrigeration cycle system. The high-temperature refrigeration cycle system is coupled with the low-temperature refrigeration cycle system through a condenser-evaporator 11.

[0033] The high-temperature refrigeration cycle system comprises a high-temperature compressor 12, the series composite heat exchange system 6, a high-temperature expansion valve 13 and the condenser-evaporator 11 which are sequentially connected through pipelines. The low-temperature refrigeration cycle system comprises a low-temperature compressor 14, the condenser-evaporator 11, a low-temperature expansion valve 15 and an ultra-low temperature system evaporator 16 which are sequentially connected through pipelines.

[0034] The internal combustion engine waste heat recovery system and the organic Rankine cycle system are coupled with the ultra-low temperature refrigeration system through the series composite heat exchange system 6. The series composite heat exchange system 6 comprises an ultra-low temperature refrigeration system condenser 601, an organic Rankine cycle system condenser 602 and an internal combustion engine cylinder liner water auxiliary condenser 603. The ultra-low temperature refrigeration system condenser 601, the organic Rankine cycle system condenser 602 and the internal combustion engine cylinder liner water auxiliary condenser 603 are coupled in series along the cooling water flow direction.

[0035] The loop inlet of the ultra-low temperature freezing system condenser 601 is connected with the outlet of the high-temperature compressor 12, the loop outlet of the ultra-low temperature freezing system condenser 601 is connected with the inlet of the high-temperature expansion valve 13, the reflux inlet of the organic Rankine cycle system condenser 602 is connected with the outlet of the expander 7, the reflux outlet of the organic Rankine cycle system condenser 602 is connected with the inlet of the liquid storage tank 8, the reflux inlet of the internal combustion engine cylinder liner water auxiliary condenser 603 is connected with the outlet of the water pump 5, and the reflux outlet of the internal combustion engine cylinder liner water auxiliary condenser 603 is connected with the inlet of the cylinder liner water heat exchanger 2.

[0036] The ultra-low temperature freezing system condenser 601, the organic Rankine cycle system condenser 602 and the internal combustion engine cylinder liner water auxiliary condenser 603 are arranged in sequence according to the heat exchange temperature, wherein the heat exchange temperature of the internal combustion engine cylinder liner water auxiliary condenser 603 is the highest, the heat exchange temperature of the ultra-low temperature freezing system condenser 601 is the lowest, and the heat exchange temperature of the organic Rankine cycle system condenser 602 is greater than that of the ultra-low temperature freezing system condenser 601 and less than that of the internal combustion engine cylinder liner water auxiliary condenser 603.

[0037] The seawater inlet of the ultra-low temperature freezing system condenser 601 is provided with a first inlet pipeline 604 and a second inlet pipeline 605, the seawater outlet of the ultra-low temperature freezing system condenser 601 is connected with a first outlet pipeline 607 through a first electric control adjusting valve 606, the first inlet pipeline 604 is connected with the seawater inlet of the ultra-low temperature freezing system condenser 601, and the second inlet pipeline 605 is connected with the first outlet pipeline 607 through a second electric control adjusting valve 608.

[0038] The first outlet pipeline 607 is connected with the seawater inlet of the organic Rankine cycle system condenser 602 through a third electric control adjusting valve 609, the seawater outlet of the organic Rankine cycle system condenser 602 is connected with a second outlet pipeline 610, the first outlet pipeline 607 is connected with the second outlet pipeline 610 through a fourth electric control adjusting valve 611, the second outlet pipeline 610 is connected with the seawater outlet of the internal combustion engine cylinder liner water auxiliary condenser 603 through a fifth electric control adjusting valve 612, and the second outlet pipeline 610 is connected with the seawater inlet of the internal combustion engine cylinder liner water auxiliary condenser 603 through a sixth electric control adjusting valve 613.

[0039] Embodiment two

[0040] The embodiment provides a control method of an organic Rankine cycle waste heat recovery and ultra-low temperature freezing coupling system, and the control method comprises the following steps:

[0041] Step one: the cylinder liner water waste heat generated by the operation of the internal combustion engine body 1 is exchanged with the circulating cooling water through the cylinder liner water heat exchanger 2, the heated circulating cooling water absorbs the flue gas waste heat generated by the operation of the internal combustion engine body 1 through the flue gas heat exchanger 3, and the temperature is further increased, and then the high-temperature cooling water enters the waste heat recovery heat exchanger 4, and exchanges heat with the high-pressure low-temperature liquid organic working medium from the outlet of the working medium pump 9, the high-pressure low-temperature liquid organic working medium absorbs heat in the waste heat recovery heat exchanger 4 and becomes high-temperature high-pressure gaseous organic working medium, the high-temperature cooling water is cooled and the temperature is reduced, and then enters the water pump 5 after being pressurized and enters the series composite heat exchange system 6 for further cooling, and after being cooled to the set temperature, it enters the cylinder liner water heat exchanger 2 again, forming a waste heat recovery cycle of the internal combustion engine body 1, wherein the high-temperature flue gas generated by the internal combustion engine body 1 is directly discharged into the atmosphere after being cooled in the flue gas heat exchanger 3;

[0042] Step two: the low-temperature liquid organic working medium from the outlet of the liquid storage tank 8 enters the working medium pump 9, is compressed into high-pressure low-temperature liquid organic working medium, and then enters the waste heat recovery heat exchanger 4 to exchange heat with the high-temperature cooling water from the flue gas heat exchanger 3, the high-pressure low-temperature liquid organic working medium absorbs heat and becomes high-temperature high-pressure gaseous organic working medium, and then enters the expander 7 to do work, becomes low-temperature low-pressure gaseous organic working medium, enters the series composite heat exchange system 6, and is cooled and released to become low-temperature low-pressure liquid organic working medium, and enters the liquid storage tank 8, forming an organic Rankine cycle, wherein the expander 7 drives the generator 10 to generate electricity by doing work, and supplies power to the ultra-low-temperature refrigeration system;

[0043] Step three: the high-temperature high-pressure gaseous refrigerant (high-temperature refrigerant) from the outlet of the high-temperature compressor 12 enters the series composite heat exchange system 6, condenses into high-temperature liquid refrigerant (high-temperature refrigerant), enters the high-temperature expansion valve 13, and is throttled into low-temperature low-pressure gas-liquid two-phase refrigerant (high-temperature refrigerant), then enters the condenser evaporator 11, exchanges heat with the high-temperature high-pressure refrigerant (low-temperature refrigerant) from the outlet of the low-temperature compressor 14, becomes low-temperature low-pressure gaseous refrigerant (high-temperature refrigerant), and then enters the high-temperature compressor 12, forming a high-temperature refrigeration cycle;

[0044] Step four: the high-temperature high-pressure gaseous refrigerant (low-temperature refrigerant) from the outlet of the low-temperature compressor 14 enters the condenser evaporator 11, exchanges heat with the low-temperature low-pressure gas-liquid two-phase refrigerant (high-temperature refrigerant) from the outlet of the high-temperature expansion valve 13, condenses into high-temperature high-pressure liquid refrigerant (low-temperature refrigerant), enters the low-temperature expansion valve 15, and is throttled into low-temperature low-pressure gas-liquid two-phase refrigerant (low-temperature refrigerant), then enters the ultra-low-temperature refrigeration system evaporator 16, absorbs heat and becomes low-temperature low-pressure gaseous refrigerant (low-temperature refrigerant), and then enters the low-temperature compressor 14, forming a low-temperature refrigeration cycle.

[0045] When the ship-used organic Rankine waste heat recovery and ultra-low temperature refrigeration coupled system provided in the embodiment runs, the internal combustion engine waste heat recovery system, the organic Rankine cycle system and the ultra-low temperature refrigeration system can realize stable operation according to automatic adjustment of the cooling seawater flow when the loads of the systems change.

[0046] When the load of the ultra-low temperature refrigeration system changes, by comparing the relationship between the inlet refrigerant supercooling degree of the high-temperature expansion valve 13 and the set value, when the inlet supercooling degree of the high-temperature expansion valve 13 is less than the set value, the load of the ultra-low temperature refrigeration system increases, the second electric regulating valve 608 is closed and the first electric regulating valve 606 is increased, so that the inlet refrigerant supercooling degree of the high-temperature expansion valve 13 is equal to the set value by increasing the cooling seawater flow into the condenser 601 of the ultra-low temperature refrigeration system;

[0047] When the inlet supercooling degree of the high-temperature expansion valve 13 is greater than the set value, the load of the ultra-low temperature refrigeration system decreases, the second electric regulating valve 608 is opened and the first electric regulating valve 606 is decreased, so that the inlet refrigerant supercooling degree of the high-temperature expansion valve 13 is equal to the set value by decreasing the cooling seawater flow into the condenser 601 of the ultra-low temperature refrigeration system;

[0048] At this time, the cooling seawater flow of the organic Rankine cycle system condenser 602 and the cooling seawater flow of the internal combustion engine cylinder liner water assisted condenser 603 are automatically adjusted according to the inlet cooling seawater temperature.

[0049] When the load of the internal combustion engine body 1 changes, the load of the organic Rankine cycle system changes, at this time, the load of the ultra-low temperature refrigeration system does not change, the cooling seawater flow of the condenser 601 of the ultra-low temperature refrigeration system is constant, the cooling seawater flow of the organic Rankine cycle system condenser 602 is automatically adjusted according to the inlet organic working medium supercooling degree of the liquid storage tank 8, when the inlet organic working medium supercooling degree of the liquid storage tank 8 is greater than the set value, the opening of the third electric regulating valve 609 is closed and the opening of the fourth electric regulating valve 611 is increased, so that the inlet organic working medium supercooling degree of the liquid storage tank 8 is equal to the set value;

[0050] When the inlet organic working medium supercooling degree of the liquid storage tank 8 is less than the set value, the opening of the third electric regulating valve 609 is increased and the opening of the fourth electric regulating valve 611 is decreased, so that the inlet organic working medium supercooling degree of the liquid storage tank 8 is equal to the set value.

[0051] The cooling seawater flow of the internal combustion engine cylinder liner water assisted condenser 603 is automatically adjusted according to the inlet water temperature of the cylinder liner water heat exchanger 2, when the inlet water temperature of the cylinder liner water heat exchanger 2 is greater than the set value, the opening of the fifth electric regulating valve 612 is increased and the opening of the sixth electric regulating valve 613 is decreased, so that the inlet water temperature of the cylinder liner water heat exchanger 2 is equal to the set value;

[0052] When the inlet water temperature of the cylinder liner water heat exchanger 2 is less than a set value, the opening of the fifth electric regulating valve 611 is reduced, and the opening of the sixth electric regulating valve 612 is increased, so that the inlet water temperature of the cylinder liner water heat exchanger 2 is equal to the set value.

[0053] The above description is merely preferred embodiments of the present application, but not to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An organic Rankine cycle waste heat recovery and ultra-low temperature freezing coupled system, characterized in that: The application relates to an internal combustion engine waste heat recovery system, an organic Rankine cycle system and an ultralow-temperature refrigeration system, wherein the internal combustion engine waste heat recovery system comprises an internal combustion engine body (1), a cylinder liner water heat exchanger (2), a flue gas heat exchanger (3), a waste heat recovery heat exchanger (4), a water pump (5) and a series-connection type composite heat exchange system (6), the cylinder liner water heat exchanger (2) is installed on the internal combustion engine body (1), the internal combustion engine body (1) and the cylinder liner water heat exchanger (2) are connected with the flue gas heat exchanger (3), the waste heat recovery heat exchanger (4) is connected with the series-connection type composite heat exchange system (6) through the water pump (5), the organic Rankine cycle system is coupled with the organic Rankine cycle system through the waste heat recovery heat exchanger (4). The organic Rankine cycle system comprises an expander (7), the series-connection type composite heat exchange system (6), a liquid storage tank (8), a working medium pump (9) and the waste heat recovery heat exchanger (4), the expander (7) is connected with a generator (10) through a mechanical transmission mechanism, the series-connection type composite heat exchange system (6) is connected with the working medium pump (9) through the liquid storage tank (8), the working medium pump (9) is connected with the expander (7) through the waste heat recovery heat exchanger (4), and the expander (7) is connected with the series-connection type composite heat exchange system (6). The ultralow-temperature refrigeration system comprises a high-temperature refrigeration cycle system and a low-temperature refrigeration cycle system, the high-temperature refrigeration cycle system is coupled with the low-temperature refrigeration cycle system through a condenser evaporator (11), the internal combustion engine waste heat recovery system and the organic Rankine cycle system are coupled with the ultralow-temperature refrigeration system through the series-connection type composite heat exchange system (6), and the series-connection type composite heat exchange system (6) is coupled in a series connection mode along a cooling water flow direction by an ultralow-temperature refrigeration system condenser (601), an organic Rankine cycle system condenser (602) and an internal combustion engine cylinder liner water auxiliary condenser (603).

2. The ORC system according to claim 1, wherein: The high-temperature refrigeration cycle system comprises a high-temperature compressor (12), the series-connection type composite heat exchange system (6), a high-temperature expansion valve (13) and the condenser evaporator (11) which are sequentially connected through pipelines, and the low-temperature refrigeration cycle system comprises a low-temperature compressor (14), the condenser evaporator (11), a low-temperature expansion valve (15) and an ultralow-temperature refrigeration system evaporator (16) which are sequentially connected through pipelines.

3. The ORC system according to claim 1, wherein: The circuit inlet and outlet of the ultralow-temperature refrigeration system condenser (601) are connected with the high-temperature compressor (12) and the high-temperature expansion valve (13) respectively, the backflow inlet and outlet of the organic Rankine cycle system condenser (602) are connected with the expander (7) and the liquid storage tank (8) respectively, and the backflow inlet and outlet of the internal combustion engine cylinder liner water auxiliary condenser (603) are connected with the water pump (5) and the cylinder liner water heat exchanger (2) respectively.

4. The ORC system of claim 1, wherein: The ultralow-temperature refrigeration system condenser (601), the organic Rankine cycle system condenser (602) and the internal combustion engine cylinder liner water auxiliary condenser (603) are arranged in sequence according to the heat exchange temperature, the heat exchange temperature of the organic Rankine cycle system condenser (602) is greater than that of the ultralow-temperature refrigeration system condenser (601) and smaller than that of the internal combustion engine cylinder liner water auxiliary condenser (603).

5. The ORC system of claim 1, wherein: The seawater inlet of the ultra-low temperature freezing system condenser (601) is provided with a first inlet pipeline (604) and a second inlet pipeline (605), the seawater outlet of the ultra-low temperature freezing system condenser (601) is connected with a first outlet pipeline (607) through a first electric control adjusting valve (606), the first inlet pipeline (604) is connected with the seawater inlet of the ultra-low temperature freezing system condenser (601), and the second inlet pipeline (605) is connected with the first outlet pipeline (607) through a second electric control adjusting valve (608).

6. The ORC waste heat recovery and ultralow temperature freezing coupled system according to claim 5, characterized in that: The first outlet pipeline (607) is connected with the seawater inlet of the organic Rankine cycle system condenser (602) through a third electric control adjusting valve (609), the seawater outlet of the organic Rankine cycle system condenser (602) is connected with a second outlet pipeline (610), the first outlet pipeline (607) is connected with the second outlet pipeline (610) through a fourth electric control adjusting valve (611), the second outlet pipeline (610) is connected with the seawater outlet of the internal combustion engine cylinder liner water auxiliary condenser (603) through a fifth electric control adjusting valve (612), and the second outlet pipeline (610) is connected with the seawater inlet of the internal combustion engine cylinder liner water auxiliary condenser (603) through a sixth electric control adjusting valve (613).

7. The control method applied to the organic Rankine cycle waste heat recovery and ultra-low temperature freezing coupled system of claim 1, characterized in that, The method comprises the following steps: Step one: the cylinder liner water waste heat generated by the operation of the internal combustion engine body (1) is exchanged with circulating cooling water through a cylinder liner water heat exchanger (2), the heated circulating cooling water absorbs the flue gas waste heat generated by the operation of the internal combustion engine body (1) through a flue gas heat exchanger (3), and the temperature of the circulating cooling water is further increased, then the high-temperature cooling water enters a waste heat recovery heat exchanger (4) and exchanges heat with high-pressure low-temperature liquid organic working medium from an outlet of a working medium pump (9), the high-pressure low-temperature liquid organic working medium is heated in the waste heat recovery heat exchanger (4) and becomes high-temperature high-pressure gaseous organic working medium, the high-temperature cooling water is cooled and lowered in temperature after heat release, and then is pressurized by a water pump (5) and enters a series composite heat exchange system (6) for further cooling, and then enters the cylinder liner water heat exchanger (2) after being cooled to a set temperature, thereby forming a waste heat recovery cycle of the internal combustion engine body (1), and the high-temperature flue gas generated by the internal combustion engine body (1) is directly discharged into the atmosphere after heat release in the flue gas heat exchanger (3); Step two: low-temperature liquid organic working medium from an outlet of a liquid storage tank (8) enters the working medium pump (9), is compressed into high-pressure low-temperature liquid organic working medium, and then enters the waste heat recovery heat exchanger (4) to exchange heat with high-temperature cooling water from the flue gas heat exchanger (3), the high-pressure low-temperature liquid organic working medium is heated and becomes high-temperature high-pressure gaseous organic working medium, and then enters an expander (7) to expand and do work, and then becomes low-temperature low-pressure gaseous organic working medium, enters the series composite heat exchange system (6) to be cooled and released, becomes low-temperature low-pressure liquid organic working medium, and then enters the liquid storage tank (8), thereby forming an organic Rankine cycle, and the expander (7) drives a generator (10) to generate electricity, thereby supplying power to electric equipment in the ultra-low temperature freezing system. Step three: high temperature and high pressure gaseous refrigerant from the outlet of high temperature compressor (12) enters into the series compound heat exchange system (6) and condenses into high temperature liquid refrigerant, then enters into high temperature expansion valve (13) and throttles into low temperature and low pressure gas-liquid two-phase refrigerant, then enters into condensing evaporator (11) and exchanges heat with high temperature and high pressure refrigerant from the outlet of low temperature compressor (14) to become low temperature and low pressure gaseous refrigerant, then enters into high temperature compressor (12) to form a high temperature refrigeration cycle; Step four: high temperature and high pressure gaseous refrigerant from the outlet of low temperature compressor (14) enters into condensing evaporator (11) and exchanges heat with low temperature and low pressure gas-liquid two-phase refrigerant from the outlet of high temperature expansion valve (13) to condense into high temperature and high pressure liquid refrigerant, then enters into low temperature expansion valve (15) and throttles into low temperature and low pressure gas-liquid two-phase refrigerant, then enters into ultra-low temperature freezing system evaporator (16) and becomes low temperature and low pressure gaseous refrigerant after absorbing heat, then enters into low temperature compressor (14) to form a low temperature refrigeration cycle.

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