A Numerical Simulation Evaluation Model and Method for Heat and Mass Transfer of Pseudosciaena crocea in Flowing Ice

Abstract

A numerical simulation evaluation model and method for heat and mass transfer of Pseudosciaena crocea under flow ice pre-cooling, including a polystyrene foam box on the outside and a copper porous metal basket on the inside. The polystyrene foam box and the copper porous metal basket are connected by symmetric first baffles and second baffles. A number of through holes are arranged on the A surface and B surface of the copper porous metal basket. Fish One, Fish Two, and Fish Three are arranged inside the copper porous metal basket. Flow ice slurry is arranged inside the polystyrene foam box and the copper porous metal basket. The present invention can not only visualize the heat and mass transfer process of flow ice on Pseudosciaena crocea during pre-cooling, but also greatly improve the accuracy of numerical simulation results, providing an optimized solution for the actual working conditions of flow ice slurry operation.

Description

Technical Field

[0001] The invention relates to the field of computer numerical simulation technology, in particular to a numerical simulation evaluation model and method for heat and mass transfer in the precooling of Pseudosciaena crocea with flowing ice slurry. Background Art

[0002] In recent years, with the improvement of people's living standards, the demand for seafood has been increasing day by day. However, the perishable nature of seafood makes it difficult to preserve for a long time. Especially during the period from the fishing ground to the market after fishing, due to limited conditions, the caught seafood is extremely easy to deteriorate. At present, the preservation of seafood on fishing boats mainly relies on solid ice, but using solid ice such as sheet ice and crushed ice for preservation during a long fishing cycle cannot achieve a good precooling and preservation effect.

[0003] The development of seawater flowing ice slurry technology has a good precooling and preservation effect on the caught fish. Especially, the heat and mass transfer phenomenon during the precooling and preservation process of flowing ice slurry plays a crucial role in fish preservation. With the development of computer science and technology, technicians can visualize this heat and mass transfer process through numerical simulation and control the precooling process using the calculation results of numerical simulation.

[0004] Among them, most researchers use models approximated to the research object to conduct numerical simulation of heat and mass transfer. When conducting numerical simulation of heat and mass transfer in fish, due to the characteristics of high water content and uneven fat distribution in the fish body, different heat and mass transfer effects are shown in different parts of the fish body. Separately studying the head, back, and abdomen of the fish has a higher accuracy in the numerical simulation of heat and mass transfer.

[0005] Based on this, in order to solve the problems that Pseudosciaena crocea cannot be quickly precooled after fishing, the precooling effect is not good, the body surface is physically damaged during the precooling process, and the heat and mass transfer process of flowing ice slurry is uncontrollable during precooling, a numerical simulation evaluation model and method for heat and mass transfer in the precooling of Pseudosciaena crocea with flowing ice slurry are designed. Summary of the Invention

[0006] The invention aims to overcome the defects in the above-mentioned prior art and provides a numerical simulation evaluation model and method for heat and mass transfer in the precooling of Pseudosciaena crocea with flowing ice slurry.

[0007] In order to achieve the above object, the technical solution adopted by the invention is: a numerical simulation evaluation model method for heat and mass transfer in the precooling of Pseudosciaena crocea with flowing ice slurry, which is characterized by including the following steps

[0008] S1. Establish a fish body model;

[0009] Establish three models of Pseudosciaena crocea with different sizes. The models of Pseudosciaena crocea are fish one, fish two, and fish three respectively; the fish bodies of fish one, fish two, and fish three are divided into fish back and fish abdomen;

[0010] S2. Establish a copper porous metal basket model;

[0011] According to the sizes of fish one, fish two, and fish three, establish a copper porous metal basket model. Fish one, fish two, and fish three are arranged in the copper porous metal basket model. A number of through holes are provided on the opposite A and B surfaces of the copper porous metal basket model.

[0012] S3. Establish a whole box model;

[0013] To divide the whole box model into two parts, establish a polystyrene foam box model outside the copper porous metal basket model, and set a first baffle and a second baffle between the copper porous metal basket model and the polystyrene foam box model. The first baffle and the second baffle are not established on the A and B surfaces of the copper porous metal basket model.

[0014] S4. Assemble the fish body model in S1 into the whole box model in S3;

[0015] Fish one, fish two, and fish three are placed in the copper porous metal basket model. Fish one, fish two, and fish three are arranged with the head and tail in the same direction and perpendicular to the A and B surfaces of the copper porous metal basket model.

[0016] S4. Introduce flowable ice;

[0017] After preparing flowable ice slurry by an ice maker, introduce the flowable ice slurry between the polystyrene foam box model and the copper porous metal basket model. The flowable ice enters from the through holes on the A surface of the copper porous metal basket model and then flows out from the B surface of the copper porous metal basket model. The flowable ice operates normally in the polystyrene foam box model for ten hours.

[0018] As a preferred embodiment of the invention, the ice content rate of the flowable ice slurry in step S4 is 20% - 50%.

[0019] As a preferred embodiment of the invention, the normal operation in step S4 is evaluated by the incomplete melting of the flowable ice.

[0020] As a preferred embodiment of the invention, the materials of the first baffle and the second baffle are polystyrene foam boards.

[0021] As a preferred embodiment of the invention, the A surface of the copper porous metal basket model is the inlet of the flowable ice slurry, and the B surface is the outlet of the flowable ice slurry.

[0022] As a preferred embodiment of the invention, the internal organ parts in the abdomen of fish one, fish two, and fish three in step S1 are set as empty areas.

[0023] A numerical simulation and evaluation model for heat and mass transfer during the precooling of large yellow croaker with flowing ice, characterized in that it includes a polystyrene foam box on the outside and a copper porous metal basket on the inside. The polystyrene foam box and the copper porous metal basket are connected by symmetric first baffles and second baffles. A number of through holes are arranged on the A surface and B surface of the copper porous metal basket, and fish one, fish two, and fish three are arranged inside the copper porous metal basket.

[0024] As a preferred embodiment of the invention, the first baffle and the second baffle divide the polystyrene foam box and the copper porous metal basket into a left interval and a right interval.

[0025] As a preferred embodiment of the invention, flowing ice slurry is arranged in the left interval and the right interval.

[0026] As a preferred embodiment of the invention, the number and intervals of the through holes on the A surface and B surface of the copper porous metal basket are the same.

[0027] The beneficial effects of the invention are:

[0028] 1. The invention can not only visualize the heat and mass transfer process of flowing ice to large yellow croaker during precooling, but also greatly improve the accuracy of numerical simulation results, providing an optimization scheme for the actual working conditions of flowing ice slurry operation.

[0029] 2. The invention divides the whole box model into zones, and can realize the numerical simulation of the effects of flowing ice slurry temperature, ice crystal mass fraction, flow rate, salt content, and fish body fatness on heat and mass transfer by computer.

[0030] 3. The invention takes into account both the overall numerical simulation of the fish body and the numerical simulation of the fish back and fish abdomen of the fish body, greatly improving the accuracy of parameters such as specific heat capacity, enthalpy change, density, heat transfer coefficient, and mass transfer coefficient of the fish head, fish back, and fish abdomen in the model. Description of the Drawings

[0031] Figure 1 is a schematic structural diagram of the invention;

[0032] Figure 2 is a top view of the invention;

[0033] Reference numerals in the drawings: polystyrene foam box 1, copper porous metal basket 2, first baffle 3, second baffle 4, fish one 5, fish two 6, fish three 7, fish back 8, fish abdomen 9, A surface 10, B surface 11, left interval 12, right interval 13. Detailed Embodiments

[0034] The following detailed description of the embodiments of the invention is provided in conjunction with the drawings.

[0035] As shown in Figures 1-2, a method for a numerical simulation and evaluation model of heat and mass transfer during the precooling of large yellow croaker with flowing ice includes the following steps

[0036] S1. Establish a fish body model;

[0037] Considering that the fatness of large yellow croaker has different effects on the heat and mass transfer effects, three models of large yellow croaker with different sizes are established. The models of large yellow croaker are Fish One 5, Fish Two 6, and Fish Three 7 respectively. Since the moisture content and fat content of the fish back and fish belly of large yellow croaker are different, and the various parameters are also different, the fish bodies of Fish One 5, Fish Two 6, and Fish Three 7 are divided into the fish back 8 and the fish belly 9. Due to the special nature of the fish viscera in the fish belly and the fact that the fish viscera can be removed during the actual processing, the visceral parts of the bellies of Fish One 5, Fish Two 6, and Fish Three 7 are set as empty areas, and the various parameters of the visceral parts are zero during the simulation process.

[0038] S2. Establish a copper porous metal basket model;

[0039] According to the sizes of Fish One 5, Fish Two 6, and Fish Three 7, a copper porous metal basket 2 model is established. Fish One 5, Fish Two 6, and Fish Three 7 are arranged in the copper porous metal basket 2 model and fixed. A number of through holes are provided on the opposite A surface 10 and B surface 11 of the copper porous metal basket 2 model.

[0040] S3. Establish a whole box model;

[0041] Since it is necessary to calculate the heat and mass transfer effects of the flowing ice slurry on the large yellow croaker under different flow velocity conditions in the numerical simulation, the box body needs to be divided into two parts, where the A surface 10 is the inlet of the flowing ice slurry and the B surface 11 is the outlet of the flowing ice slurry. Therefore, a polystyrene foam box 1 model is established outside the copper porous metal basket 2 model, and a first baffle 3 and a second baffle 4 are arranged between the copper porous metal basket 2 model and the polystyrene foam box 1 model. The first baffle 3 and the second baffle 4 are not established on the A surface 10 and B surface 11 of the copper porous metal basket 2 model.

[0042] S4. Assemble the fish body model in S3 whole box model;

[0043] Fish One 5, Fish Two 6, and Fish Three 7 are placed in the copper porous metal basket 2 model, with their heads and tails in the same direction and arranged vertically to the A surface 10 and B surface 11 of the copper porous metal basket 2 model;

[0044] S4. Introduce flowing ice;

[0045] After preparing the fluid ice slurry with an ice maker, the fluid ice slurry is introduced between the polystyrene foam box 1 model and the copper porous metal basket 2 model. Considering the operating conditions of the fluid ice slurry ice maker and the actual precooling effect, the ice content rate of the fluid ice slurry actually introduced into the foam box is 20% - 50%. The fluid ice enters through the 10 through-holes on the A side of the copper porous metal basket 2 model and flows out from the B side 11 of the copper porous metal basket 2 model. The fluid ice operates normally in the polystyrene foam box 1 model for ten hours, and the normal operation is evaluated by the incomplete melting of the fluid ice.

[0046] In step S1, the body lengths of fish one 5, fish two 6, and fish three 7 are set to 320 mm, 300 mm, and 280 mm in sequence, which is beneficial for numerical simulation under different conditions of fish body fatness during the heat and mass transfer process of fluid ice to large yellow croaker.

[0047] In step S1, fish one 5, fish two 6, and fish three 7 are divided into two parts, namely the fish back 8 and the fish belly 9, because the water content and fat content of different parts of the large yellow croaker are different, and parameters such as enthalpy change, specific heat capacity, heat transfer coefficient, and mass transfer coefficient are also different. Therefore, subdividing the parts is beneficial to improving the accuracy of the numerical simulation results.

[0048] A numerical simulation evaluation model for the heat and mass transfer of fluid ice precooling of large yellow croaker includes an outer polystyrene foam box 1 and an inner copper porous metal basket 2. The polystyrene foam box 1 and the copper porous metal basket 2 are connected by symmetric first baffles 3 and second baffles 4. A number of through-holes are arranged on the A side 10 and B side 11 of the copper porous metal basket 2, which facilitate the flow of the fluid ice slurry. Fish one 5, fish two 6, and fish three 7 are arranged inside the copper porous metal basket 2. The copper porous metal basket 2 model ensures that the large yellow croaker does not displace during the flow of the fluid ice slurry. According to the real structure and body shape of the large yellow croaker, including the length, thickness, and body contour of the fish body, the models of fish one 5, fish two 6, and fish three 7 are established using Solidworks. At the same time, in order to ensure the universality and applicability of the large yellow croaker model, the ratio of fish one 5, fish two 6, and fish three 7 to the fish entity is 1:1, and the lengths of fish one 5, fish two 6, and fish three 7 are preferably 320 mm, 300 mm, and 280 mm. In addition, the influence of the internal organs of the fish on heat and mass transfer can be ignored. Therefore, during the modeling process, the internal organ parts of the fish belly of fish one 5, fish two 6, and fish three 7 are set as empty areas.

[0049] The first baffle 3 and the second baffle 4 divide the polystyrene foam box 1 and the copper porous metal basket 2 into a left interval 12 and a right interval 13, and the fluid ice slurry is arranged in the left interval 12 and the right interval 13.

[0050] The number and spacing of the through holes on the A surface 10 and B surface 11 of the copper porous metal basket 2 are the same. The presence of the through holes is to simulate the seamless contact between the flowing ice slurry and the large yellow croaker, which is beneficial to the preservation of the large yellow croaker. The consistent arrangement of the through holes on the A surface 10 and B surface 11 ensures the uniform inflow and outflow of the flowing ice slurry.

[0051] Among them, the polystyrene foam box 1, the first baffle 3, and the second baffle 4 are all made of polystyrene material. The excellent heat insulation characteristics of the polystyrene material result in a longer heat preservation time than ordinary materials, which is beneficial to the subsequent numerical simulation calculation.

[0052] The above description of the disclosed embodiments enables those skilled in the art to implement or use the invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

[0053] Although the terms such as the polystyrene foam box 1, the copper porous metal basket 2, the first baffle 3, the second baffle 4, fish one 5, fish two 6, fish three 7, the fish back 8, the fish belly 9, the A surface 10, the B surface 11, the left interval 12, the right interval 13, etc. are used more in this article, the possibility of using other terms is not excluded. These terms are only used to more conveniently describe and explain the essence of the invention. Interpreting them as any additional limitation is contrary to the spirit of the invention.

Claims

1. A numerical simulation and evaluation model method for heat and mass transfer in pre-cooling of large yellow croaker with flowing ice, characterized in that, It includes the following steps: S1. Establish a fish body model: Establish three large yellow croaker models of different sizes, namely fish one (5), fish two (6), and fish three (7); the fish bodies of fish one (5), fish two (6), and fish three (7) are divided into a fish back part (8) and a fish belly part (9); S2. Establish a copper porous metal basket model: According to the sizes of fish one (5), fish two (6), and fish three (7), establish a copper porous metal basket (2) model. Fish one (5), fish two (6), and fish three (7) are arranged in the copper porous metal basket (2) model. A number of through holes are opened on the opposite A surface (10) and B surface (11) of the copper porous metal basket (2) model. The number and intervals of the through holes on the A surface (10) and B surface (11) are the same; S3. Establish a whole box model: To divide the whole box model into two parts, establish a polystyrene foam box (1) model outside the copper porous metal basket (2) model, and set a first baffle (3) and a second baffle (4) between the copper porous metal basket (2) model and the polystyrene foam box (1) model. The first baffle (3) and the second baffle (4) are not established on the A surface (10) and B surface (11) of the copper porous metal basket (2) model. The first baffle (3) and the second baffle (4) divide the polystyrene foam box (1) and the copper porous metal basket (2) into a left interval (12) and a right interval (13); S4. Assemble the fish body model in step S1 into the whole box model in step S3: Fish one (5), fish two (6), and fish three (7) are placed in the copper porous metal basket (2) model, with fish one (5), fish two (6), and fish three (7) having the same head and tail direction and being arranged vertically with respect to the A surface (10) and B surface (11) of the copper porous metal basket (2) model; S4. Introduce flowing ice: After preparing flowing ice slurry by an ice maker, introduce the flowing ice slurry between the polystyrene foam box (1) model and the copper porous metal basket (2) model, that is, between the left interval (12) and the right interval (13). The flowing ice enters from the through holes on the A surface (10) of the copper porous metal basket (2) model and flows out from the B surface (11) of the copper porous metal basket (2) model. The flowing ice operates normally in the polystyrene foam box (1) model for ten hours.

2. The numerical simulation and evaluation model method for heat and mass transfer of Pseudosciaena crocea pre-cooled by flowing ice according to claim 1, characterized in that In step S4, the ice content rate of the flowing ice slurry is 20% - 50%.

3. A numerical simulation and evaluation model method for heat and mass transfer in pre-cooling of large yellow croaker with flowing ice, characterized in that, In step S4, normal operation is evaluated by the incomplete melting of the flowing ice.

4. A numerical simulation evaluation model method for heat and mass transfer of Pseudosciaena crocea pre-cooled by flowing ice according to claim 1, characterized in that, The materials of the first baffle (3) and the second baffle (4) are polystyrene foam boards.

5. A numerical simulation evaluation model method for heat and mass transfer of Pseudosciaena crocea pre-cooled by flowing ice, characterized in that, The A surface (10) of the copper porous metal basket (2) model is the inlet of the flowing ice slurry, and the B surface (11) is the outlet of the flowing ice slurry.

6. The method for evaluating a numerical simulation model of heat and mass transfer in pre-cooling of large yellow croaker with flowing ice according to claim 1, wherein In step S1, the internal organ parts in the bellies of fish one (5), fish two (6), and fish three (7) are set as empty areas.

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