A refrigeration system, method of use, and refrigeration appliance

Abstract

The application discloses a refrigeration system, a use method and a refrigeration device. The refrigeration system comprises a throttling valve, an evaporator, a first three-way valve, a compressor, a second three-way valve, an ejector, a one-way check valve, a condenser, a connecting valve, a working medium pump and a generator. The throttling valve is connected with the evaporator, and the evaporator is connected with the first left valve. The first right valve and the second right valve are connected with the ejector. The first upper valve is connected with the compressor, and the compressor is connected with the second lower valve. The ejector and the second left valve are connected with the condenser, and the one-way check valve is arranged between the ejector and the condenser. The second branch of the condenser is connected with the throttling valve, the first branch of the condenser is connected with the generator, the generator is connected with the ejector, and the working medium pump and the connecting valve are arranged between the condenser and the generator. Through flexible adjustment of the first three-way valve, the second three-way valve and other valves, flexible coupling of a waste heat driven ejector type and a vapor compression type refrigeration cycle mode is realized, and the adaptability to variable refrigeration working conditions is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of refrigeration technology, in particular to a refrigeration system, a use method and a refrigeration device. BACKGROUND

[0002] The demand for cold chain logistics is increasing, and as the most important link of cold chain logistics, the refrigerated transportation link has high energy consumption problem. The logistics cost of the cold chain transportation process accounts for 70% of the total cost of the transportation product process. The refrigerated transportation of perishable goods has low transportation rate and high loss rate in high temperature transportation environment. Therefore, energy saving and emission reduction for refrigerated transportation link and the adaptability of refrigeration system of refrigerated transportation equipment to variable working conditions have very important practical value.

[0003] Frozen goods are stored in the frozen goods warehouse of the cold chain transportation equipment, such as large refrigerated trucks, ships, etc. It needs to face the higher external environment temperature in the transportation process. Therefore, a high-power compressor driven vapor compression refrigeration system is usually installed in the transportation equipment. The compressor in this refrigeration system is driven by the engine of the transportation equipment. For example, the effective thermal efficiency of a typical diesel engine for transportation is only 40% (in order to drive the electric compression refrigeration unit, a part of the power must be consumed). The remaining fuel energy is directly discharged to the atmosphere in the form of engine cylinder exhaust and cylinder sleeve water waste heat. The recovery and utilization potential of this part of low-grade waste heat is huge. If the waste heat is used to drive the refrigeration equipment instead of the existing vapor compression refrigeration system, it will effectively reduce the additional fuel consumption and operating cost of the refrigerated transportation process.

[0004] Under this background, the waste heat driven ejector refrigeration system has a bright application prospect in the field of future new generation refrigerated transportation waste heat refrigeration technology due to its simple structure, high reliability and easy miniaturization. However, there are still two key technical problems in widely applying this refrigeration technology to refrigerated transportation equipment. One is that the low-temperature refrigeration performance of the traditional heat-driven ejector refrigeration system is poor. The ejector is used as a supercharging component of the refrigeration system, which replaces the compressor. However, its own operation performance is poor for large compression ratio working conditions. There is a large pressure difference between the high condensation temperature (pressure) in the refrigerated transportation process and the low temperature and pressure refrigeration working conditions. It is difficult to maintain the large compression ratio working condition requirement by relying on the ejector alone as a supercharging component, and the refrigeration coefficient is low. The second is that the traditional waste heat driven ejector refrigeration system must be maintained under stable driving heat source supply conditions. However, the engine load of the refrigerated transportation vehicle and ship varies during driving, and even stops driving. The waste heat supply is insufficient or even interrupted. In order to maintain the low temperature environment of the goods storage warehouse, emergency measures must be considered, and an auxiliary electric driven compression refrigeration unit must be introduced to maintain the refrigeration demand.

[0005] It is obviously not practical to install two types of refrigeration systems on a space-limited refrigerated transport vehicle or ship, and in addition, the cargo storage room needs to maintain a stable low-temperature storage environment during transportation, and the refrigeration system needs to be kept running efficiently and stably to maintain the corresponding low-temperature storage temperature. Therefore, a new composite refrigeration system with flexible adjustable working mode and a corresponding flexible regulation strategy are needed. SUMMARY

[0006] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application proposes a refrigeration system that can flexibly regulate and switch refrigeration cycle modes, overcoming the shortcomings of traditional waste heat driven ejector refrigeration systems, such as reduced refrigeration capacity due to insufficient driving heat source supply, inability to maintain refrigeration conditions, poor adaptability to variable refrigeration conditions, and inability to refrigerate during engine shutdown.

[0007] The present application also proposes a method for using the above refrigeration system.

[0008] The present application also proposes a refrigeration device comprising the above refrigeration system.

[0009] According to the refrigeration system of the first aspect of the present application, the refrigeration system comprises a throttling valve, an evaporator, a first three-way valve, a compressor, a second three-way valve, an ejector, a one-way check valve, a condenser, a connecting valve, a working medium pump, and a generator.

[0010] The first three-way valve has a first left valve that can be opened and closed, a first upper valve, and a first right valve, and the second three-way valve has a second left valve that can be opened and closed, a second lower valve, and a second right valve.

[0011] The outlet of the throttling valve is connected to the inlet of the evaporator, and the outlet of the evaporator is connected to the first left valve.

[0012] The first right valve and the second right valve are connected to the entrainment fluid inlet of the ejector.

[0013] The first upper valve is connected to the inlet of the compressor, and the outlet of the compressor is connected to the second lower valve.

[0014] The outlet of the ejector and the second left valve are connected to the inlet of the condenser, and the one-way check valve is arranged between the outlet of the ejector and the inlet of the condenser.

[0015] The outlet of the condenser has a first branch and a second branch, the second branch is connected to the inlet of the throttling valve, the first branch is connected to the inlet of the generator, the outlet of the generator is connected to the working fluid inlet of the ejector, and the working medium pump and the connecting valve are arranged between the outlet of the condenser and the generator.

[0016] The refrigeration system according to the first aspect of the present application has at least the following beneficial effects: through flexible adjustment of the first three-way valve, the second three-way valve and other valves, flexible coupling of the waste heat driven ejector refrigeration cycle mode, the auxiliary pressurized waste heat driven ejector refrigeration cycle mode and the vapor compression refrigeration cycle mode is realized, and adaptability to variable refrigeration conditions is significantly improved.

[0017] In the refrigeration system according to the first aspect of the present application, when the connection valve is connected, the first upper valve is closed, the second three-way valve and the compressor are closed, and the first left valve and the first right valve are opened, the refrigeration system enters the waste heat driven ejector refrigeration cycle mode without auxiliary pressurization.

[0018] The low-temperature working medium at the outlet of the throttling valve enters the evaporator to absorb heat, and after refrigeration, enters the ejector through the first three-way valve as an injection fluid, is pressurized to the condensing pressure in the ejector, and then is output from the ejector to enter the condenser through the one-way check valve, becomes liquid working medium after heat release in the condenser, one of the liquid working medium enters the working medium pump through the connection valve, and then flows into the generator after pressurization, and then enters the ejector as working fluid after absorbing waste heat energy, and the other liquid working medium returns to the throttling valve to expand, and the cycle is repeated.

[0019] In the refrigeration system according to the first aspect of the present application, when the connection valve is connected, the first right valve and the second left valve are closed, and the first left valve, the first upper valve, the second lower valve, the second right valve and the compressor are opened, the refrigeration system enters the auxiliary pressurized waste heat driven ejector refrigeration cycle mode.

[0020] The low-temperature working medium at the outlet of the throttling valve enters the evaporator to absorb heat, and after refrigeration, enters the compressor through the first three-way valve for auxiliary pressurization, the pressurized superheated gaseous working medium enters the ejector through the second three-way valve as an injection fluid, is pressurized to the condensing pressure in the ejector, and then is output from the ejector to enter the condenser through the one-way check valve, becomes liquid working medium after heat release in the condenser, one of the liquid working medium enters the working medium pump through the connection valve, and then flows into the generator after pressurization, and then enters the ejector as working fluid after absorbing waste heat energy, and the other liquid working medium returns to the throttling valve to expand, and the cycle is repeated.

[0021] In the refrigeration system according to the first aspect of the present application, when the connection valve is closed, the first right valve and the second right valve are closed, and the first left valve, the first upper valve, the second lower valve, the second left valve and the compressor are opened, the refrigeration system enters the compressor driven vapor compression refrigeration cycle mode.

[0022] The low-temperature working medium of the throttle valve outlet absorbs heat in the evaporator, and after refrigeration, enters the compressor through the first three-way valve for auxiliary supercharging. The supercharged overheated gaseous working medium enters the condenser through the second three-way valve for condensation and heat release. The condensed working medium enters the throttle valve, and the cycle is repeated.

[0023] The refrigeration system according to the first aspect of the present application further comprises a processor, a plurality of temperature sensors and a plurality of pressure sensors, each of the temperature sensors and the pressure sensors is arranged on the evaporator, the condenser and the generator respectively, and the processor is connected with each of the temperature sensors and the pressure sensors.

[0024] The first three-way valve and the second three-way valve are three-way stop valves according to the first aspect of the present application.

[0025] The connecting valve is a detachable connecting valve according to the first aspect of the present application.

[0026] The compressor is an electrically driven variable frequency compressor, which is adapted to change the compression ratio by variable frequency adjustment according to the first aspect of the present application.

[0027] The method for using the refrigeration system according to the second aspect of the present application comprises:

[0028] When the waste heat supply is sufficient and the refrigeration load is in a preset range, the connecting valve is connected, the first upper valve is closed, the second three-way valve and the compressor are closed, and the first left valve and the first right valve are opened, so that the refrigeration system enters a waste heat driven ejector refrigeration cycle mode without auxiliary supercharging;

[0029] When the waste heat supply is sufficient and the refrigeration load increases, the connecting valve is connected, the first right valve and the second left valve are closed, and the first left valve, the first upper valve, the second lower valve, the second right valve and the compressor are opened, so that the refrigeration system enters a waste heat driven ejector refrigeration cycle mode with auxiliary supercharging;

[0030] When the waste heat supply is insufficient, the connecting valve is closed, the first right valve and the second right valve are closed, and the first left valve, the first upper valve, the second lower valve, the second left valve and the compressor are opened, so that the refrigeration system enters a compressor driven vapor compression refrigeration cycle mode.

[0031] The refrigeration equipment according to the third aspect of the present application comprises the refrigeration system according to the first aspect of the present application.

[0032] It is understandable that the method for using the refrigeration system in the second aspect of the present application and the refrigeration device in the third aspect of the present application both have the technical effects of the refrigeration system in the first aspect of the present application as described above, and thus will not be described again.

[0033] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0034] The present application will be further described below in conjunction with the accompanying drawings and embodiments;

[0035] Figure 1 System schematic diagram of the waste heat driven ejector refrigeration cycle mode without auxiliary supercharging of the embodiments of the present application;

[0036] Figure 2 System schematic diagram of the waste heat driven ejector refrigeration cycle mode with auxiliary supercharging of the embodiments of the present application;

[0037] Figure 3 System schematic diagram of the compressor driven vapor compression refrigeration cycle mode of the embodiments of the present application.

[0038] REFERENCE NUMERALS

[0039] Throttle valve 1, evaporator 2, first three-way valve 3, first left valve 3a, first right valve 3b, first upper valve 3c, compressor 4, second three-way valve 5, second left valve 5a, second right valve 5b, second lower valve 5c, ejector 6, one-way check valve 7, condenser 8, connecting valve 9, working medium pump 10, generator 11. DETAILED DESCRIPTION

[0040] The embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0041] In the description of the present application, it is understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0042] In the description of the present application, the meaning of one or more is one or more, the meaning of multiple is at least two, greater than, less than, more than, etc. is not included in the number, above, below, etc. is understood to include the number. If the first, second is described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the sequence of indicated technical features.

[0043] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical scheme.

[0044] Reference Figures 1 to 3 The refrigeration system of the first aspect embodiment of the present application is applied to cold chain transportation logistics equipment such as refrigerated transport vehicles, ships, etc. The refrigeration system comprises a throttling valve 1, an evaporator 2, a first three-way valve 3, a compressor 4, a second three-way valve 5, an ejector 6, a one-way check valve 7, a condenser 8, a connecting valve 9, a working medium pump 10, and a generator 11.

[0045] The first three-way valve 3 has a first left valve 3a, a first upper valve 3c and a first right valve 3b which can be opened and closed, and the second three-way valve 5 has a second left valve 5a, a second lower valve 5c and a second right valve 5b which can be opened and closed.

[0046] The outlet of the throttling valve 1 is connected with the inlet of the evaporator 2, and the outlet of the evaporator 2 is connected with the first left valve 3a. The first right valve 3b and the second right valve 5b are connected with the entraining fluid inlet of the ejector 6. The first upper valve 3c is connected with the inlet of the compressor 4, and the outlet of the compressor 4 is connected with the second lower valve 5c. The outlet of the ejector 6 and the second left valve 5a are connected with the inlet of the condenser 8, and the one-way check valve 7 is arranged between the outlet of the ejector 6 and the inlet of the condenser 8. The outlet of the condenser 8 has a first branch and a second branch, the second branch is connected with the inlet of the throttling valve 1, and the first branch is connected with the inlet of the generator 11. The outlet of the generator 11 is connected with the working fluid inlet of the ejector 6. The working medium pump 10 and the connecting valve 9 are arranged between the outlet of the condenser 8 and the generator 11. Through flexible adjustment of the first three-way valve, the second three-way valve and other valves, flexible coupling of the waste heat driven ejector refrigeration cycle mode, the auxiliary supercharged waste heat driven ejector refrigeration cycle mode and the vapor compression refrigeration cycle mode is realized, and the adaptability to variable refrigeration conditions is significantly improved.

[0047] It should be noted that the low-medium grade energy such as engine exhaust or boiler waste heat inside the vehicle or ship is used as the driving heat source, and through the introduction of the first three-way valve 3, the second three-way valve 5, the one-way check valve 7 and other mechanisms, the refrigeration system can be flexibly switched between the three working modes of the waste heat driven ejector refrigeration cycle, the auxiliary supercharged-heat driven ejector refrigeration cycle and the vapor compression refrigeration cycle.

[0048] In some embodiments of the present application, with particular reference to Figure 1 When the engine exhaust or boiler waste heat supply is sufficient and stable, the connecting valve 9 is connected, the first upper valve 3c is closed, the second three-way valve and the compressor 4 are closed, and the first left valve 3a and the first right valve 3b are opened, so that the refrigeration system enters the waste heat driven ejector refrigeration cycle mode. More specifically, this mode is a heat driven ejector refrigeration cycle mode without auxiliary supercharging. When the refrigeration system is switched to this mode in the stable driving state of the refrigerated transport equipment, the waste heat energy input to the system is sufficient, and the auxiliary supercharging device is not needed, and the heat driven ejector refrigeration system can maintain the refrigeration working condition of the cargo refrigeration compartment.

[0049] The system cycle is: the low-temperature working medium at the outlet of the throttling valve 1 enters the evaporator 2 to absorb heat and generate a refrigeration effect, becoming saturated gaseous working medium, and after refrigeration, as an injection fluid, enters the ejector 6 through the first three-way valve, mixes with the high-temperature and high-pressure working fluid, and is pressurized to the condensing pressure, and then is output from the ejector 6 to enter the condenser 8 through the one-way check valve 7, and after condensing and releasing heat, becomes liquid working medium, and at the outlet of the condenser 8, the liquid working medium is divided into two streams, one of which enters the working medium pump 10 through the connecting valve 9, is pressurized, and then flows into the generator 11, absorbs waste heat energy, and becomes high-temperature and high-pressure working fluid, which enters the ejector 6 as working fluid, and the other stream of the liquid working medium expands in the throttling valve 1, and the cycle continues.

[0050] In some embodiments of the present application, with particular reference to Figure 2 When the waste heat energy supply is reduced and cannot meet the refrigeration demand, that is, when the refrigerated transport equipment is in a low load working condition, the engine exhaust waste heat is reduced, and the internal cargo storage compartment is in a refrigeration demand working condition, the compressor 4 automatically adjusts the speed to realize auxiliary supercharging of the working medium at the outlet of the evaporator 2, and improve the performance of the ejector 6 mixed compression when the driving heat source energy is insufficient. At this time, the connecting valve 9 is connected, the first right valve 3b and the second left valve 5a are closed, and the first left valve 3a, the first upper valve 3c, the second lower valve 5c, the second right valve 5b and the compressor 4 are opened, so that the refrigeration system enters the auxiliary supercharged-waste heat driven ejector refrigeration cycle mode.

[0051] The system cycle is: the low-temperature working medium at the outlet of the throttling valve 1 enters the evaporator 2 to absorb heat, becomes saturated gas and generates refrigeration effect, and then enters the compressor 4 through the first three-way valve to be assisted to be pressurized, the overheat gas working medium pressurized as the injection fluid enters the ejector 6 through the second three-way valve, mixes with the high-temperature and high-pressure working fluid, and is pressurized to the condensing pressure, and then is output from the ejector 6 to enter the condenser 8 through the one-way check valve 7, becomes liquid working medium after heat release, and is branched at the outlet of the condenser 8, one branch of the liquid working medium enters the working medium pump 10 through the connecting valve 9, flows into the generator 11 after being pressurized, and enters the ejector 6 as the working fluid after absorbing the residual heat energy, and the other branch of the liquid working medium expands in the throttling valve 1, and the cycle is repeated.

[0052] In some embodiments of the present application, with particular reference to Figure 3 When the engine of the transport equipment is shut down and cannot provide residual heat, in order to ensure that the refrigeration and freezing compartments are in normal working state, the refrigeration system will switch to the current working mode to maintain the low-temperature environment of the cargo storage room, the connecting valve 9 is closed, the first right valve 3b and the second right valve 5b are closed, the first left valve 3a, the first upper valve 3c, the second lower valve 5c, the second left valve 5a and the compressor 4 are opened, so that the refrigeration system enters the vapor compression refrigeration cycle mode driven by the compressor 4 alone.

[0053] The system cycle is: the low-temperature working medium at the outlet of the throttling valve 1 enters the evaporator 2 to absorb heat, becomes saturated gas and generates refrigeration effect, and then enters the compressor 4 through the first three-way valve to be assisted to be pressurized, the overheat gas working medium pressurized as the injection fluid enters the ejector 6 through the second three-way valve, mixes with the high-temperature and high-pressure working fluid, and is pressurized to the condensing pressure, and then is output from the ejector 6 to enter the condenser 8 through the one-way check valve 7, becomes liquid working medium after heat release, and is branched at the outlet of the condenser 8, one branch of the liquid working medium enters the working medium pump 10 through the connecting valve 9, flows into the generator 11 after being pressurized, and enters the ejector 6 as the working fluid after absorbing the residual heat energy, and the other branch of the liquid working medium expands in the throttling valve 1, and the cycle is repeated.

[0054] In some embodiments of the present application, the refrigeration system further comprises a processor, a plurality of temperature sensors and a plurality of pressure sensors, each temperature sensor and pressure sensor is arranged on the evaporator 2, the condenser 8 and the generator 11 respectively, and the processor is connected with each temperature sensor and pressure sensor. More specifically, the first three-way valve 3 and the second three-way valve 5 are set as three-way cock valves. The connecting valve 9 is a separable connecting valve 9. The compressor 4 is a variable frequency compressor 4 driven by electricity, and the compressor 4 is suitable for variable frequency adjustment to change the compression ratio.

[0055] It should be noted that in the non-steady state condition of the change of the driving heat source, by dynamically adjusting the frequency of the variable frequency auxiliary compressor 4, the engine residual heat change, the refrigeration load change and other non-steady state conditions can be flexibly adapted, so as to realize the maximum utilization of the useful energy of the residual heat and maintain the stable operation of the refrigeration system.

[0056] It should be noted that the ejector 6 acts as the main supercharging device, and the main function is to compress the low-temperature and low-pressure working medium from the evaporator 2 through the compression effect of the supersonic flow. The compressor 4 is an auxiliary supercharging device, which reduces the pressure ratio of the ejector 6, improves the compression performance, keeps the system in a high-efficiency operation state, and maximizes the utilization of waste heat. Compared with the traditional heat-driven ejector refrigeration system, the adaptability to non-steady-state working conditions is more excellent.

[0057] It should be noted that the one-way check valve 7 prevents the working medium at the outlet of the ejector 6 from flowing back. The compressor 4 is an electrically driven rotary compressor 4 with a speed-adjustable function, which can flexibly adjust the compression ratio of the compressor 4.

[0058] It should be noted that the automatic / manual switching system composed of various temperature and pressure sensors, processors, three-way stop valves, one-way check valves 7 and other valves can flexibly switch the working mode of the refrigeration system by monitoring the parameters of some key components of the system in real time through the sensors and operating specific valves when certain conditions are met.

[0059] Reference Figures 1 to 3 The use method of the refrigeration system of the second aspect embodiment of the present application can be the use method of the refrigeration system of the first aspect embodiment of the present application, and the use method comprises:

[0060] When the waste heat supply is sufficient and the refrigeration load is in a preset interval, such as in a large refrigerated vehicle or ship, the exhaust waste heat supply is sufficient when the engine is normally running. The connecting valve 9 is connected, the first upper valve 3c is closed, the second three-way valve and the compressor 4 are closed, and the first left valve 3a and the first right valve 3b are opened, so that the refrigeration system enters the waste heat-driven ejector refrigeration cycle mode without auxiliary supercharging;

[0061] When the waste heat supply is sufficient and the refrigeration load increases, the connecting valve 9 is connected, the first right valve 3b and the second left valve 5a are closed, the first left valve 3a, the first upper valve 3c, the second lower valve 5c, the second right valve 5b and the compressor 4 are opened, so that the refrigeration system enters the waste heat-driven ejector refrigeration cycle mode with auxiliary supercharging;

[0062] When the waste heat supply is insufficient, the connecting valve 9 is closed, the first right valve 3b and the second right valve 5b are closed, the first left valve 3a, the first upper valve 3c, the second lower valve 5c, the second left valve 5a and the compressor 4 are opened, so that the refrigeration system enters the vapor compression refrigeration cycle mode driven by the compressor 4 alone.

[0063] Specifically, when the refrigeration system is in the waste heat driven ejector refrigeration cycle mode without auxiliary supercharging, the medium and low grade useful energy in the engine exhaust can be fully recovered and utilized, and the variable refrigeration condition can be flexibly adjusted by adjusting the frequency of the variable frequency compressor 4.

[0064] Specifically, when the refrigeration system is in the waste heat driven ejector refrigeration cycle mode with auxiliary supercharging, the medium and low grade useful energy in the engine exhaust can be fully recovered and utilized, and the variable refrigeration condition can be flexibly adjusted by adjusting the frequency of the variable frequency compressor 4. When the refrigeration condition changes, such as the refrigeration load increases, the refrigeration temperature decreases, etc., the evaporation temperature and pressure decrease. At this time, the heat driven ejector refrigeration is not enough to drive the ejector fluid with too low temperature and pressure. By adjusting and increasing the frequency of the auxiliary compressor 4, the compression ratio of the compressor 4 to the working medium at the outlet of the evaporator 2 is increased, so as to make up for the pressure difference between the evaporation pressure after the refrigeration condition changes and the set working condition of the ejector fluid.

[0065] Specifically, when the refrigeration system is in the compressor 4 driven vapor compression refrigeration cycle mode, the working condition of the refrigeration load increase can also be flexibly adapted by increasing the compression ratio of the compressor 4.

[0066] Referring to Figures 1 to 3 The specific embodiments of the refrigeration system of the present application include:

[0067] The temperature sensor and the pressure sensor are placed in the generator 11, the evaporator 2, the condenser 8 and the reasonable position of the cargo storage room, and are connected with the processor to monitor the real-time running temperature and pressure data in the corresponding equipment;

[0068] The high and low temperature and pressure thresholds are set, and the setting rules are:

[0069] The steady state evaporation temperature of the evaporator 2 is set as T1, and the minimum evaporation temperature is set as T2, wherein the setting rules are: the corresponding refrigeration temperature of the standard refrigeration condition in the cargo storage room is set as T1; T2 is the lowest temperature that can be ejected by the heat driven ejector refrigeration cycle to work normally, the steady state evaporation pressure P1 of the evaporator 2 and the minimum evaporation pressure P2 are set, wherein P1 is the saturation state pressure corresponding to the cycle working medium at temperature T1, and P2 is the saturation state pressure of the cycle working medium at temperature T2;

[0070] The minimum generation temperature T3 of the generator 11 is set, and the setting rule is: T3 is set as the minimum generation temperature that can maintain the normal work of the ejector refrigeration system without relying on the auxiliary compressor 4, and can meet the standard refrigeration condition of the cargo storage room, the minimum generation pressure P3 of the generator 11 is set, and P3 is set as the saturation state temperature of the cycle working medium at the minimum generation temperature T3 of the generator 11.

[0071] The highest condensing temperature threshold at the outlet of condenser 8 is set to T4 (the temperature at which the refrigerant leaves the condenser), and the corresponding highest condensing pressure threshold is P4. The setting rule for P4 is the maximum back pressure that the ejector 6 can withstand under the reference operating conditions when it can maintain stable ejection performance without relying on the auxiliary compressor 4. The setting rule for T4 is the saturated liquid temperature corresponding to the circulating refrigerant pressure of P4.

[0072] Let Ts be the temperature measured by the temperature sensor inside the cold storage warehouse.

[0073] Let Te be the evaporation temperature measured by the temperature sensor inside evaporator 2; and let Pe be the evaporation pressure measured by the pressure sensor.

[0074] Let the generating temperature measured by the temperature sensor inside generator 11 be Tg; let the generating pressure measured by the pressure sensor be Pg;

[0075] Let Tc be the working fluid condensation temperature at the outlet of condenser 8 measured by the temperature sensor inside condenser 8; and let Pc be the working fluid condensation pressure at the outlet of condenser 8 measured by the pressure sensor.

[0076] To prevent unnecessary and frequent start-stop of compressor 4 from damaging compressor 4 and other equipment or causing system instability, this system introduces a control method based on monitoring system parameters using temperature and pressure sensors, and sets the refrigeration mode switching rules for the composite refrigeration system as follows:

[0077] State 1: When Tg≥T3, Pg≥P3, Te=T1, Pe=P1, the refrigeration system is in Mode 1, i.e., a heat-driven jet refrigeration cycle mode without auxiliary pressurization, as shown in the attached diagram. Figure 1 As shown, at this time, since the engine exhaust waste heat supply is sufficient and the refrigeration condition is basically stable, the auxiliary compressor 4 is completely shut off, and the low temperature condition in the cargo storage warehouse can be maintained entirely by relying on the waste heat to drive the jet refrigeration system, making full use of the useful work in the engine exhaust waste heat.

[0078] State 2: When Tg≥T3, Pg≥P3, Te≤T1, Pe≤P1, the refrigeration system is in Mode 2, a heat-driven jet refrigeration cycle mode with auxiliary pressurization, as shown in the attached diagram. Figure 2 As shown, in order to make the most of the useful energy in the exhaust waste heat of the engine and improve the entrainment and ejection capability of the heat-driven jet refrigeration system, the auxiliary compressor 4 is started to increase the pressure of the ejector fluid entering the injector 6, thereby improving the refrigeration capacity of the waste heat-driven jet refrigeration cycle.

[0079] State 3: When Tg < T3 and Pg < P3, the refrigeration system switches to mode 3, which is an electrically driven vapor compression refrigeration cycle, as shown in the attached diagram. Figure 3As shown, at this time, due to engine stop, insufficient supply of waste heat, the working vapor temperature and pressure generated in the generator 11 are low, and the ejector refrigeration cycle cannot be driven to operate, at this time, in order to ensure the refrigeration temperature of the goods warehouse of the transport equipment, as an emergency measure, the refrigeration system operating mode is switched to a mode driven by the vapor compression refrigeration cycle alone, and the refrigeration working condition is maintained.

[0080] To achieve the above object, the present application is described in detail below in combination with the accompanying drawings Figure 1 , the accompanying Figure 2 , and the accompanying Figure 3 , the method for switching the refrigeration system between the three operating modes is described in detail:

[0081] The current refrigeration mode is mode 1: waste heat driven ejector refrigeration cycle without auxiliary supercharging, due to the system operating condition changing from state 1 to state 2, the refrigeration mode needs to be switched to mode 2: waste heat driven ejector refrigeration cycle with auxiliary supercharging; the method for switching from mode 1 to mode 2 is: keeping the first left valve 3a and the first upper valve 3c of the first three-way cock valve open, closing the first right valve 3b thereof, closing the second left valve 5a of the second three-way cock valve, and keeping the second lower valve 5c and the second right valve 5b open. The connection valve 9 remains connected, and the others remain unchanged, wherein the function of the one-way check valve 7 is to prevent the circulating working medium flowing out via the ejector 6 from flowing back into the ejector 6, the flow direction of the check valve is from the outlet of the ejector 6 to the inlet of the condenser 8, when switching from refrigeration mode 1 to mode 2, the operation should be opposite to the above description;

[0082] The current refrigeration mode is mode 1: heat driven ejector refrigeration cycle without auxiliary supercharging, due to the system operating condition changing from state 1 to state 3, the refrigeration mode needs to be switched to mode 3: electric driven vapor compression refrigeration system; the method for switching from mode 1 to mode 3 is: the first upper valve 3c and the first left valve 3a of the first three-way cock valve are open, the first right valve 3b of the first three-way cock valve is kept closed, the second right valve 5b of the second three-way cock valve is closed, and the second lower valve 5c and the second left valve 5a thereof are open; the others remain unchanged, wherein the function of the one-way check valve 7 is to prevent the circulating working medium flowing out via the second left valve 5a of the second three-way cock valve from flowing back into the ejector 6, the flow direction of the check valve is from the outlet of the ejector 6 to the inlet of the condenser 8, when switching from refrigeration mode 3 to mode 1, the operation should be opposite to the above description;

[0083] When the current refrigeration mode is mode 2: auxiliary supercharged hot-driven ejector refrigeration cycle, and the system operating condition changes from state 2 to state 3, the refrigeration mode needs to be switched to mode 3: electric-driven vapor compression refrigeration cycle. The method for switching from mode 2 to mode 3 is as follows: keep the second lower valve 5c of the second three-way cock valve open, close the second right valve 5b of the second three-way cock valve, open the second left valve 5a, cut off the connecting valve 9, and keep other unchanged. The function of the one-way check valve 7 is to prevent the circulating working medium flowing out of the second left valve 5a of the second three-way cock valve from flowing into the ejector 6. The flow direction of the check valve is from the outlet of the ejector 6 to the inlet of the condenser 8. When the refrigeration mode is switched from mode 2 to mode 1, the operation should be opposite to the above.

[0084] When the refrigeration system operates in mode 1, i.e. the waste heat-driven ejector refrigeration cycle without auxiliary supercharging, the engine operates stably, the driving heat source of the ejector refrigeration cycle is supplied stably, the refrigeration condition in the cargo storage room is stable, the auxiliary compressor 4 of the refrigeration system is completely stopped, and the useful work in the engine exhaust waste heat can be maximally utilized.

[0085] In order to maximize the flexible adaptability of the refrigeration system to variable working conditions, the control strategies of the system when the working conditions change are described in detail below, respectively for the temperature of the evaporator 2, the working conditions in the generator 11 and the condenser 8,

[0086] When the refrigeration system operates in mode 2, when the following conditions occur alone or simultaneously, the speed of the auxiliary compressor 4 should be increased, and the compression ratio of the compressor 4 should be increased.

[0087] When Ts rises, it indicates that the temperature in the cargo refrigeration room rises, and in order to maintain the refrigeration condition, the refrigeration temperature needs to be reduced, so the evaporation temperature Te and the evaporation pressure Pe need to be reduced. At this time, according to the evaporation pressure drop and the amplitude of deviating from the original design evaporation pressure T1, the speed of the compressor 4 is increased accordingly;

[0088] When the sensor real-time monitors that the generation temperature Tg and the generation pressure Pg of the working medium in the generator 11 drop, at this time it indicates that the engine working condition of the refrigerated transport equipment changes, the engine exhaust waste heat supply decreases, the temperature and pressure of the circulating working medium in the generator 11 will decrease accordingly, and the working fluid energy driving the ejector 6 decreases. In order to maintain the working condition requirement of the ejector refrigeration system that the circulating working medium is compressed to the condensation pressure, the temperature and pressure on the side of the fluid induced by the ejector 6 need to be increased. Therefore, according to the sensor detecting that the real-time generation temperature Tg and the generation pressure Pg in the generator 11 drop and the amplitude of deviating from the original design generation temperature T3 and the generation pressure P3, the speed of the compressor 4 is increased accordingly;

[0089] The sensor monitors the condensing temperature Tc > T4 and the condensing pressure Pc > P4 in real time, which indicates that the refrigeration transport process enters a higher temperature external environment. In order to ensure that the circulating working medium is smoothly condensed and heat-released in the condenser 8 to become a liquid-phase working medium and then complete the refrigeration cycle, the condensing temperature and the condensing pressure of the refrigerant need to be correspondingly increased. At this time, the discharge pressure of the mixed fluid at the outlet of the ejector 6 needs to be increased, that is, the ejector 6 will face a non-design condition in which the actual discharge back pressure is higher than the design critical back pressure. In order to improve the entraining performance of the ejector 6 under the non-design condition, the rotational speed of the compressor 4 is correspondingly increased according to the difference between the actual discharge back pressure of the ejector 6 and the critical back pressure, the pressure ratio of the auxiliary compressor 4 is increased, and the pressure of the entrained fluid entering the ejector 6 is increased.

[0090] When the refrigeration system is in mode 3, the rotational speed of the auxiliary compressor 4 needs to be increased when the following conditions occur alone or simultaneously:

[0091] Ts rises, which indicates that the temperature inside the refrigerated cargo compartment rises. In order to maintain the refrigeration condition, the refrigeration temperature needs to be reduced, so the evaporation temperature Te and the evaporation pressure Pe need to be reduced. At this time, the rotational speed of the compressor 4 is correspondingly increased according to the decrease of the evaporation pressure and the deviation of the original design evaporation pressure T1.

[0092] The sensor monitors the condensing temperature Tc > T4 and the condensing pressure Pc > P4 in real time, which indicates that the refrigeration transport process enters a higher temperature external environment. In order to ensure that the circulating working medium is smoothly condensed and heat-released in the condenser 8 to become a liquid-phase working medium and then complete the refrigeration cycle, the condensing temperature and the condensing pressure of the refrigerant need to be correspondingly increased. At this time, the discharge pressure of the mixed fluid at the outlet of the ejector 6 needs to be increased, that is, the ejector 6 will face a non-design condition in which the actual discharge back pressure is higher than the design critical back pressure. In order to improve the entraining performance of the ejector 6 under the non-design condition, the rotational speed of the compressor 4 is correspondingly increased according to the difference between the actual discharge back pressure of the ejector 6 and the critical back pressure, the pressure ratio of the auxiliary compressor 4 is increased, and the pressure of the entrained fluid entering the ejector 6 is increased.

[0093] With reference to Figures 1 to 3 The refrigeration equipment of the third aspect embodiment of the present application can be a cold chain transport logistics equipment such as a refrigerated transport vehicle and a ship. The refrigeration equipment includes the refrigeration system of the first aspect embodiment of the present application, and can flexibly switch between three refrigeration cycle modes according to the operating condition of the cold chain transport equipment and the change of the refrigeration condition.

[0094] The technical features of the above-described embodiments can be combined in any manner. In order to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but it should be considered that any combination of the technical features is within the scope of the present application as long as the combination does not exist.

[0095] The embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. A method of using a refrigeration system, characterized in that, A refrigeration system is used, the refrigeration system comprising: a throttle valve, an evaporator, a first three-way valve, a compressor, a second three-way valve, an ejector, a one-way check valve, a condenser, a connecting valve, a working fluid pump, and a generator; The first three-way valve has a first left valve, a first upper valve, and a first right valve that can be opened and closed; the second three-way valve has a second left valve, a second lower valve, and a second right valve that can be opened and closed. The outlet of the throttle valve is connected to the inlet of the evaporator, and the outlet of the evaporator is connected to the first left valve; The first right valve and the second right valve are connected to the ejector fluid inlet; The first upper valve is connected to the inlet of the compressor, and the outlet of the compressor is connected to the second lower valve; The outlet of the ejector and the second left valve are connected to the inlet of the condenser, and the one-way check valve is disposed between the outlet of the ejector and the inlet of the condenser; The condenser outlet has a first branch and a second branch, the second branch is connected to the inlet of the throttle valve, the first branch is connected to the inlet of the generator, the generator outlet is connected to the working fluid inlet of the ejector, and the working fluid pump and the connecting valve are disposed between the condenser outlet and the generator; The method of using the refrigeration system includes: When the waste heat supply is sufficient and the cooling load is within the preset range, the connecting valve is connected, the first upper valve is closed, the second three-way valve and the compressor are closed, and the first left valve and the first right valve are opened, so that the refrigeration system enters the waste heat driven jet refrigeration cycle mode without auxiliary pressurization. When the waste heat supply is sufficient and the cooling load increases, the connecting valve is connected, the first right valve and the second left valve are closed, and the first left valve, the first upper valve, the second lower valve, the second right valve and the compressor are opened, so that the refrigeration system enters the waste heat driven jet refrigeration cycle mode with auxiliary pressurization. When the waste heat supply is insufficient, the connecting valve is closed, the first right valve and the second right valve are closed, and the first left valve, the first upper valve, the second lower valve, the second left valve and the compressor are opened, so that the refrigeration system enters the vapor compression refrigeration cycle mode driven by the compressor alone.

2. The method of using the refrigeration system according to claim 1, characterized in that: The connecting valve is connected, the first upper valve is closed, the second three-way valve and the compressor are closed, and the first left valve and the first right valve are open, so that the refrigeration system enters the waste heat driven jet refrigeration cycle mode without auxiliary pressurization. The low-temperature working fluid from the outlet of the throttle valve enters the evaporator to absorb heat. After cooling, it becomes an ejector fluid that enters the ejector through the first three-way valve. After being pressurized to the condensing pressure, it exits the ejector and enters the condenser through the one-way check valve. After condensing and releasing heat, it becomes a liquid working fluid. One stream of liquid working fluid enters the working fluid pump through the connecting valve. After being pressurized, it flows into the generator. After absorbing waste heat energy, it becomes a working fluid that enters the ejector. The other stream of liquid working fluid returns to the throttle valve to expand, and this cycle continues.

3. The method of using the refrigeration system according to claim 1, characterized in that: The connecting valve is connected, the first right valve and the second left valve are closed, and the first left valve, the first upper valve, the second lower valve, the second right valve and the compressor are open, so that the refrigeration system enters the waste heat driven jet refrigeration cycle mode with auxiliary pressurization; The low-temperature working fluid from the outlet of the throttle valve enters the evaporator to absorb heat. After cooling, it enters the compressor through the first three-way valve for auxiliary pressurization. The pressurized superheated gaseous working fluid acts as an ejector fluid, entering the ejector through the second three-way valve. After being pressurized to the condensing pressure, it exits from the ejector and enters the condenser through the one-way check valve. After condensing and releasing heat, it becomes a liquid working fluid. One stream of liquid working fluid enters the working fluid pump through the connecting valve, and after being pressurized, it flows into the generator. After absorbing waste heat energy, it enters the ejector as a working fluid. The other stream of liquid working fluid returns to the throttle valve to expand, and this cycle continues.

4. The method of using the refrigeration system according to claim 1, characterized in that: The connecting valve is closed, the first right valve and the second right valve are closed, and the first left valve, the first upper valve, the second lower valve, the second left valve and the compressor are open, so that the refrigeration system enters the vapor compression refrigeration cycle mode driven by the compressor alone; The low-temperature working fluid at the outlet of the throttle valve enters the evaporator to absorb heat. After cooling, it enters the compressor through the first three-way valve for auxiliary pressurization. The pressurized superheated gaseous working fluid enters the condenser through the second three-way valve to condense and release heat. After condensation, the working fluid enters the throttle valve, and the cycle continues.

5. The method of using the refrigeration system according to any one of claims 1 to 4, characterized in that: The refrigeration system also includes a processor, multiple temperature sensors, and multiple pressure sensors. Each of the temperature sensors and pressure sensors is respectively disposed on the evaporator, the condenser, and the generator. The processor is connected to each of the temperature sensors and pressure sensors.

6. The method of using the refrigeration system according to claim 5, characterized in that: The first three-way valve and the second three-way valve are configured as three-way plug valves.

7. The method of using the refrigeration system according to claim 5, characterized in that: The connecting valve is a detachable connecting valve.

8. The method of using the refrigeration system according to claim 5, characterized in that: The compressor is an electrically driven variable frequency compressor, which is adapted to change the compression ratio by frequency conversion.

9. A refrigeration device, characterized in that, include: The method of using the refrigeration system as described in any one of claims 1 to 8.

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