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CN-121997783-A - Method and algorithm for determining operation parameters of refrigeration system of cold therapy cabin

CN121997783ACN 121997783 ACN121997783 ACN 121997783ACN-121997783-A

Abstract

The invention discloses a method and an algorithm for determining operation parameters of a refrigeration system of a cold therapy cabin, which comprise the following steps of collecting parameters by a sensor in the refrigeration system, determining the mass composition of fluid by measuring the density of the fluid, determining the state parameters of the fluid by a pressure sensor and a temperature sensor, calculating thermodynamic parameters of the refrigeration system of the cold therapy cabin, wherein the parameters comprise the density of liquid phase refrigerant, the mass components of gas-liquid separation, the enthalpy value of mixing points of condensation evaporators at all levels, the enthalpy value of the condensation evaporators at all levels and the enthalpy value of the evaporators, determining the operation parameters of the system according to the thermodynamic parameters of the refrigeration system, and predicting the circulation components, the cooling capacity and the system COP by the algorithm, so that the thermodynamic efficiency of the refrigeration system is improved, and the refrigeration system of the cold therapy cabin is stably and efficiently operated according to the predicted actual operation parameters.

Inventors

  • XU HU
  • CHEN MINGZHI

Assignees

  • 厦门纳智壳生物科技有限公司

Dates

Publication Date
20260508
Application Date
20240415

Claims (10)

  1. 1. A method and an algorithm for determining the operation parameters of a refrigeration system of a cold therapy cabin are characterized by comprising the following steps: S1, acquiring parameters by a sensor in a refrigeration system, wherein a flow sensor is used for determining the mass composition of fluid by measuring the density of the fluid, and a pressure and temperature sensor is used for determining the state parameters of the fluid; S2, thermodynamic parameter calculation of a refrigeration system of the cold therapy cabin, wherein the parameters comprise liquid phase refrigerant density, gas-liquid separation of each component mass component, mixing point enthalpy values of condensation evaporators at all levels, enthalpy values of the condensation evaporators at all levels and evaporator enthalpy values; S3, determining system operation parameters according to thermodynamic parameters of the refrigerating system, predicting circulation components, cooling capacity and system COP, and realizing stable and efficient operation of the refrigerating system of the cold therapy cabin according to the predicted actual operation parameters.
  2. 2. The method and algorithm for determining the operating parameters of a cooling system of a cooling treatment compartment according to claim 1, wherein the density of the liquid phase refrigerant is evaluated according to a Refprop refrigerant physical property database, thermodynamic properties of the non-azeotropic refrigerant R-290/R-23/R-14 are evaluated, an equation for determining the physical property parameters using the Refprop database is (h, ρ, x, t..+ -.) =f ('p 1', 'p2', Z), wherein Z is a non-azeotropic refrigerant mass composition, calculated according to the refrigerant charge G R290 /G R23 /G R14 ＝Z R290_initial /Z R23_initial /Z R14_initial , and parameters p1 and p2 to be determined are acquired by a system sensor, and p1 and p2 are acquired temperature and pressure parameters, respectively.
  3. 3. The method and algorithm for determining the operating parameters of a cooling system of a cooling treatment cabin according to claim 1, wherein the parameters of the mass components of the gas-liquid separation are determined, the phase separation in the gas-liquid separator can be calculated by using Bell & Deiters correlation, according to the separation rule provided in Refprop, the mass components of saturated liquid and steam in equilibrium state are [ Z l,GLS ,Z g,GLS ]＝f(p i , Z ] through the pressure of the gas-liquid separator and the mass components at the inlet, no chemical interaction exists between non-azeotropic refrigerants, the separated components satisfy the balance of mass and energy, The quality of the liquid phase is improved, Gas phase mass; Wherein the non-azeotropic mixed refrigerant has the mass balance of each component; Wherein the energy of each component of the non-azeotropic mixed refrigerant is balanced;
  4. 4. The method and algorithm for determining the operation parameters of the refrigeration system of the cold therapy compartment according to claim 1, wherein the enthalpy values of the mixing points of the condensation evaporators at each stage are respectively (C, mix-1), (D, mix-2) and (E, mix-3), the mixing point (C, mix-1) is composed of a branch throttle TOF- (C, mix-1), an electronic expansion valve EXV-1- (C, mix-1) and an out_2- (C, mix-1) of the condensation evaporator CE_MTS at each stage, the mixing point (D, mix-2) is composed of a branch electromagnetic throttle valve ETOF-2- (D, mix-2), an electronic expansion valve EXV-2- (D, mix-2) and an out_2 (D, mix-2) of the condensation evaporator CE_LTS at each stage, the mixing point (E, mix-3) is composed of a plurality of the electromagnetic throttle valves ETOF-2- (D, mix-2) and the mixing points (E, mix-2) of the electronic expansion valves CE_5-LTS at each stage and the refrigerating compartment at each stage, the mixing point (D, mix-2) is composed of the same number of the mixing points of the electromagnetic throttle valves ETOF-2- (D, mix-2) at each stage and the mixing point (C, mix-2) at each stage is different in the refrigeration compartment (C, the refrigerating system at each stage) and the different refrigerating cycle of the mixing points of the refrigerating system, the mixing points at different temperatures (80 ℃, mix-2), and the mixing points of the refrigeration system participating in the refrigeration cycle are (C, mix-1), (D, mix-2) and (E, mix-3) when the temperature in the cabin is minus 110 ℃.
  5. 5. The method and algorithm for determining the operation parameters of the refrigerating system of the cold therapy cabin according to claim 4, wherein the temperature refrigeration in the cabin at-40 ℃ is performed, and the branch of the mixing point (C, mix-1) involved in the mixing is a throttle valve TOF (C, mix-1) and an electronic expansion valve EXV-1 (C, mix-1); The temperature refrigeration in the cabin at the temperature of 80 ℃ below zero, the branch of the mixing point (C, mix-1) participating in mixing is throttle valve TOF- (C, mix-1) and OUT_2- (C, mix-1) of the CE_MTS of the medium temperature condensation evaporator, the branch of the mixing point (D, mix-2) participating in mixing is electromagnetic throttle valve ETOF-2- (D, mix-2) and electronic expansion valve EXV-2- (D, mix-2); The temperature refrigeration in the cabin at the temperature of 110 ℃ below zero, the mixing point (C, mix-1) and the mixing point (D, mix-2) are respectively a throttle valve TOF (C, mix-1), an OUT_2 (C, mix-1) of the CE_MTS of the medium temperature stage condensation evaporator, an OUT_2 (D, mix-2) of the CE_LTS of the low temperature stage condensation evaporator, and the mixing point (E, mix-3) and EXV-3 (D, mix-2) are respectively an electromagnetic throttle valve ETOF-5 (E, mix-3) and an EXV-3; Wherein the enthalpy values of the electronic expansion valves EXV-1- > (C, mix-1), EXV-1- > (D, mix-2) and EXV-1- > (D, mix-2) are the enthalpy values of the fluid output from the bottom liquid phase outlet L of the respective upstream gas-liquid separators GLS for the different branch electronic expansion valves EXV-1- > (C, mix-1), EXV-2/EXV-3, wherein the electronic expansion valves EXV-1/EXV-2/EXV-3 are free of mass loss before and after and the enthalpy values are unchanged, wherein the enthalpy values of the intermediate temperature stage condensation evaporator ce_mts are the enthalpy values of the intermediate temperature stage condensation evaporator ce_2 outlet, and the enthalpy values of the intermediate temperature stage condensation evaporator ce_mts_2 are the enthalpy values of the low temperature stage condensation evaporator ce_2, and the enthalpy values of the intermediate temperature stage condensation evaporator ce_2 are the enthalpy values of the low temperature stage condensation evaporator ce_2.
  6. 6. The method and algorithm for determining the operation parameters of the cooling system according to claim 5, wherein the-40 ℃ in-cabin temperature cooling mode has an enthalpy h C,mix-1 | -40℃ ＝h l,GLS-1 | -40℃ +h F,o | -40℃ of the mixing point (C, mix-1), the-80 ℃ in-cabin temperature cooling mode has an enthalpy h C,mix-1 | -80℃ ＝h l,GLS-1 | -80℃ +h CE_MTS,OUT_2 | -80℃ of the mixing point (C, mix-1), an enthalpy h D,mix-2 | -80℃ ＝h l,GLS-2 | -80℃ +h F,o | -80℃ of the mixing point (D, mix-2), the-110 ℃ in-cabin temperature cooling mode has an enthalpy h C,mix-1 | -110℃ ＝h l,GLS-1 | -110℃ +h CE_MTS,OUT_2 | -110℃ of the mixing point (C, mix-1), an enthalpy h D,mix-2 | -110℃ ＝h l,GLS-2 | -110℃ +h CE_LTS,OUT_2 | -110℃ of the mixing point (D, mix-2), and an enthalpy h E,mix-3 | -110℃ ＝h l,GLS-3 | -110℃ +h F,o | -110℃ of the mixing point (E, mix-3).
  7. 7. The method and algorithm for determining the operating parameters of a cooling system of a cooling treatment cabin according to claim 1, wherein the condensation evaporators of each stage have enthalpy values, the condensation evaporators of high, medium and low temperature stages have 4 ends at both sides and two pairs of inlet and outlet, wherein the inlet and outlet of one side are condensing sides and the inlet and outlet of the other side are evaporating sides, the heat exchange capacity of the condensation evaporators is Q CE ＝K·A·Δt m , the heat exchange capacity of the condensation evaporators is Q cd , the heat exchange capacity of the evaporating sides is Q ev , and the condensation evaporators have Q cd ＝Q ev ＝Q CE , wherein the logarithmic average temperature difference of the condensation evaporators is The condensation side heat exchange amount Q cd ＝m cd ·(h cd,in -h cd,out ), the evaporation side heat exchange amount Q ev ＝m ev ·(h ev,in -h ev,out ).
  8. 8. The method and algorithm for determining operating parameters of a cooling system of a therapeutic compartment of claim 1, wherein the evaporator enthalpy is Q EHX ＝K·A·Δt m ＝m EHX ·(h EHX,in -h EHX,out ).
  9. 9. The method and algorithm for determining the operation parameters of the cooling system of the cold therapy compartment according to any one of claims 1 to 8, wherein S3 determines the operation parameters of the system according to the thermodynamic parameters of the cooling system, the compressed zeotropic mixed working medium is divided into two fluids at the state point (a), wherein the fluid liquid phase component passing through the state point (B, i-mr) is Z B,i-mr , and the fluid liquid phase component passing through the state point bypass (a, bp) is Z A,bp ; according to 35 refrigerant physical property database, according to ρ g =f (t, p, Z), wherein the non-azeotropic refrigerant mass composition Z is iterated continuously, the physical parameter fluid density ρ g is determined to be close to ρ rt-g collected by a mass flowmeter, the mass composition Z A,bp of the non-azeotropic mixed working medium passing through the state point bypass (A, bp) can be obtained, the fluid composition Z B,i-mr ＝Z-Z A-bp passing through the state point (B, i-mr) can be obtained, the two-phase non-azeotropic refrigerant with the composition Z B,i-mr enters the inlet (GLS-1, i) of the gas-liquid separator GLS-1, the fluid temperature of the fluid mass composition Z l,GLS flowing out of the liquid phase port L and the fluid temperature of the fluid mass composition Z g,GLS flowing out of the gas phase port G and the fluid temperature of the inlet (GLS-1, i) can be known by the formula in the calculation and the determination of the mass composition of the gas-liquid separation components, and the pressure in the gas-liquid separator GLS-1 is correlated, Z l,GLS-1 and Z g,GLS-1 can be determined by real-time acquisition of the inlet temperature t GLS-1,i of the gas-liquid separator GLS-1 and the pressure P GLS-1 in the GLS-1, the non-azeotropic refrigerant has no chemical interaction, the separated components satisfy the balance of mass and energy, and the mass components of the non-azeotropic mixed refrigerant are determined And Determination of energy values for non-azeotropic refrigerant mixtures And
  10. 10. The method according to claim 1, wherein the refrigerant has no mass loss and constant enthalpy before and after throttling, the pressure and temperature before and after throttling change, and the liquid phase mixed fluid flowing out from the liquid phase outlet L of the gas-liquid separator GLS-1 passes through the throttle valve TOF, and the refrigerant has no mass loss and constant enthalpy.

Description

Method and algorithm for determining operation parameters of refrigeration system of cold therapy cabin Technical Field The invention relates to the technical field of refrigeration systems, in particular to a method and an algorithm for determining operation parameters of a refrigeration system of a cold therapy cabin. Background The determination of the operation parameters of the refrigerating system can adjust the composition ratio of the internal refrigerant, improve the thermodynamic efficiency of the refrigerating system, obtain the state of the refrigerant according to the sensor assembly arranged at the inlet and outlet after the refrigerant passes through one electronic assembly, and further predict the energy ratio and the composition ratio when the refrigerant reaches the cold therapy cabin, so that the stable and efficient operation of the refrigerating system of the cold therapy cabin can be realized. Disclosure of Invention The invention aims to provide a method and an algorithm for determining the operation parameters of a refrigeration system of a cold therapy cabin, so as to solve the problem that the operation parameters of the refrigeration system are determined in the background art to realize stable and efficient operation of the system. In order to achieve the above purpose, the invention adopts the following technical scheme: A method and algorithm for determining the operation parameters of a refrigerating system of a cold therapy cabin comprise the following steps S1, acquiring parameters by a sensor in a refrigeration system, wherein a flow sensor is used for determining the mass composition of fluid by measuring the density of the fluid, and a pressure and temperature sensor is used for determining the state parameters of the fluid; S2, thermodynamic parameter calculation of a refrigeration system of the cold therapy cabin, wherein the parameters comprise liquid phase refrigerant density, gas-liquid separation of each component mass component, mixing point enthalpy values of condensation evaporators at all levels, enthalpy values of the condensation evaporators at all levels and evaporator enthalpy values; S3, determining system operation parameters according to thermodynamic parameters of the refrigerating system, predicting circulation components, cooling capacity and system COP, and realizing stable and efficient operation of the refrigerating system of the cold therapy cabin according to the predicted actual operation parameters. The density of the liquid-phase refrigerant is evaluated according to Refprop refrigerant physical property database, thermodynamic property of non-azeotropic refrigerant R-290/R-23/R-14 is evaluated, and equation for determining physical property parameter by using Refprop database is (H, ρ, x, t.) is =f ('p 1', 'p2', Z) formula 1 Wherein Z is the mass composition of the non-azeotropic refrigerant, the parameters p1 and p2 to be determined are acquired through a system sensor according to the refrigerant filling quantity G R290/GR23/GR14＝ZR290_initial/ZR23_initial/ZR14_initial, and p1 and p2 are acquired temperature and pressure parameters respectively. The parameters of the mass components of the gas-liquid separation are determined, the phase separation in the gas-liquid separator can be calculated by using Bell & Deiters correlation, according to the separation rule provided in Refprop, the mass components of saturated liquid and steam in equilibrium state are calculated by the pressure of the gas-liquid separator and the mass components at the inlet [ Z l,GLS,Zg,GLS]＝f(pi, Z) equation 2 Wherein Z l,GLS is the mass fraction of the liquid phase fluid output from the bottom outlet L of the gas-liquid separator, and wherein Z g,GLS is the mass fraction of the liquid phase fluid output from the bottom outlet G of the gas-liquid separator; No chemical interaction exists between the non-azeotropic refrigerants, each separated component meets the balance of mass and energy, Wherein the method comprises the steps ofThe quality of the liquid phase is improved,Gas phase mass; Wherein the non-azeotropic mixed refrigerant has the mass balance of each component; Wherein the energy of each component of the non-azeotropic mixed refrigerant is balanced; The enthalpy values of the mixing points of the condensation evaporators at all levels are respectively (C, mix-1), (D, mix-2) and (E, mix-3) at the high, medium and low temperature levels in the refrigeration system; the mixing point (C, mix-1) consists of a branch throttle TOF & gtC, mix-1), an electronic expansion valve EXV-1 & gtC, mix-1 and an out_2 & gtC, mix-1 of a medium temperature stage condensation evaporator CE_MTS, the mixing point (D, mix-2) consists of a branch electromagnetic throttle ETOF-2 & gtD, mix-2, an electronic expansion valve EXV-2 & gtD, mix-2 and an out_2 & gtD of a low temperature stage condensation evaporator CE_LTS, the mixing point (E, mix-3) consists of an electromagnetic throttle