One, cold storage is mainly used for frozen food processing and cold storage, it is through artificial refrigeration, so that the room to maintain a certain low temperature. Cold storage walls, floors and flat roofs are laid with a certain thickness of insulation material to reduce the incoming heat from the outside world. In order to reduce the absorption of the sun's radiant energy, the surface of the cold storage wall is generally painted white or light color. Thus, the cold storage building and general industrial and civil construction is different, has its unique structure.
Cold storage building to prevent the diffusion of water vapor and air infiltration. Outdoor air intrusion not only increases the cold storage of cold consumption, but also to the warehouse with moisture, moisture condensation caused by the building structure, especially the heat insulation structure is damaged by moisture freezing, so to set up moisture insulation layer, so that the cold storage building has a good sealing and moisture vapor barrier performance.
The foundation of cold storage is affected by low temperature, the moisture in the soil is easy to be frozen. Because the soil volume expansion after freezing, will cause the ground rupture and the whole building structure deformation, serious will make the cold storage can not be used. For this reason, low-temperature cold storage floor in addition to an effective heat insulation layer, the heat insulation layer must also be treated under the soil to prevent freezing.
The floor of the cold storage to stack a large number of goods, and to pass a variety of loading and unloading transportation machinery and equipment, flat roof also has refrigeration equipment or pipeline. Therefore, its structure should be strong and have a large bearing capacity.
Low-temperature environment, especially in the cyclical freezing and thawing cycle process, the building structure is vulnerable to damage. Therefore, the cold storage of cold storage panels and cold storage of the various parts of the construction should have sufficient frost resistance.
In general, cold storage equipment is to ensure the quality of the building with its strict insulation, sealing, robustness and frost resistance. The quality of the building is guaranteed.
Two, 1. Civil cold storage equipment
This is currently building more of a cold storage, can be built into a single or multi-storey. The main body of the building is generally reinforced concrete frame structure or brick structure. Civil cold storage enclosure structure is a heavy structure, thermal inertia, outdoor air temperature fluctuations and the enclosure structure of the external surface of the solar radiation caused by the temperature fluctuations during the day and night, in the enclosure structure attenuation is greater, so the enclosure structure of the internal surface temperature fluctuations are smaller, the library temperature is easy to stabilize.
2. Combined plate cold storage
This cold storage equipment for the single-layer form, the library board for the steel frame lightweight prefabricated insulation board assembly structure, its load-bearing components are made of thin-walled steel. The inner and outer panels of the library board are colored steel (base material is galvanized steel), the core material of the library board is foamed rigid polyurethane or paste polystyrene foam board. As all components, except the ground, are prefabricated in sets in specialized factories according to uniform standards and assembled on site, the construction progress is fast and the construction cycle is short.
3. Cladding cold storage
It is also known as the earth kiln cold storage, the cave body for the arch structure, there is a single cave body type, there is also a continuous arch form. Generally masonry, and a certain thickness of loess cover as a heat insulation layer. Used as a low-temperature soil-covered cold storage, the foundation of the cave body should be in the sandstone layer or bedrock that is not easy to freeze and expand. Because it has the advantages of local conditions, local materials, construction is simple, low cost, sturdy and durable, etc., in the northwest of China has been greater development.
4. Cave cold storage
Generally constructed in the rock is relatively hard, good integrity of the rock layer, the inner side of the cave is generally for lining or spray anchor treatment, the thickness of the rock layer of the cave body is generally covered by not less than 20 m.
A cold storage of the composition of the cold storage
Cold storage by the storage body of the building and refrigeration control consists of two major components. According to the different uses of the constituent buildings, it can be divided into four major parts: cold processing room and cold storage room, production auxiliary room, living auxiliary room and production auxiliary room.
Three, 1. Cold storage enclosure structure
Cold storage through the enclosure structure of the run cold and cold storage enclosure structure unit heat flow is directly proportional. Therefore, should be more in the reduction of cold storage of cold storage enclosure structure unit heat flow index work. To reduce the enclosure structure unit heat flow, one is the thermal conductivity of the insulation material to be small, the second is the enclosure structure layer to be thick. However, the thickness is generally not too thick, otherwise there will be an increase in construction costs and waste of space and other issues. Therefore, it is necessary to select the insulation material in the appropriate thickness range. Usually the thermal conductivity of the insulation material is required to be small, low water absorption, good low temperature resistance, the cost can not be too high.
Commonly used cold storage insulation materials are rice husk, polystyrene foam, polyurethane cool rigid foam and so on. Rice husk is convenient, but the thermal resistance is small, easy to absorb moisture, and the dosage is large, the library body construction labor and time-consuming, the cost is actually not lower than the polystyrene; polystyrene foam manufacturers, easy to buy, the thermal resistance is large, the price is moderate, the construction and installation of convenient; polyurethane rigid foam thermal resistance is the largest, the best thermal insulation performance, but the price is high.
2. Cold storage enclosure structure of moisture and steam
Cold storage enclosure structure to take measures to prevent moisture and steam is also necessary, otherwise it will make the insulation material insulation performance deterioration. This is the cold storage body just started to use the insulation performance is good, but with a period of time after the deterioration of the insulation effect of the reason. As water vapor is from the high temperature side to the low temperature side of the infiltration, therefore, moisture vapor barrier should be located in the high temperature side of the insulation layer.
3. Cold storage evaporation pressure and temperature
Evaporation temperature and evaporation pressure is corresponding to the evaporation pressure, know the evaporation pressure, evaporation temperature can be derived by checking the table. In the cold storage room temperature under certain conditions, the temperature difference (evaporation temperature and the difference between the temperature of the room) to narrow the evaporation temperature can be increased accordingly, the cold storage refrigeration will improve the cooling capacity, that is, the cycle efficiency improved, and accordingly also save electricity.
4. Cold storage frost operation
In general, when the evaporator surface frost on the air resistance is not yet significant, through the evaporator air flow has not yet been reduced before the impact of the frost layer is not yet serious, you do not have to frost; when the flow of air is significantly reduced, the frost should be carried out. The greater the humidity of the air, the greater the difference between the evaporator temperature and the cold storage temperature, the easier it is to frost on the evaporator, combined with the preservation process, as far as possible, the use of packaged refrigeration can reduce the dry consumption of fruits and vegetables, reduce the number of times the evaporator defrosting, actually also played a role in energy conservation of cold storage.
5. Cold storage temperature and cold storage room utilization
Different fruits and vegetables storage temperature is different, each kind of fruit and vegetables also have a temperature range suitable for its storage. Without affecting the quality of fruits and vegetables, energy-saving cold storage should be selected with a higher storage temperature. Cold storage temperature is high, the evaporation temperature of the refrigeration system is also a corresponding increase in the refrigerator's cooling capacity will be improved, the cycle efficiency is also certainly improved. Improve the cold storage temperature is more important is also can reduce the heat transfer through the library body to the outside. Energy-saving cold storage warehouse utilization rate is the fruit and vegetables occupy the volume and the ratio of the effective volume of the warehouse. For micro cold storage volume utilization rate is generally not less than 0.3, of course, can not be too high, otherwise there are cooling difficulties. For the volume of fruits and vegetables to be stored changes, should be separated into two or more cold storage cold storage room. In addition to choose a reasonable storage cycle, which is self-evident to the energy-saving cold storage.
Four, mini energy-saving cold storage equipment, the main features:
(1) mini energy-saving cold storage refrigerant charging and debugging in the factory by the completion of a rigorous test, while the installation is convenient and quick, only need to indoor units and outdoor units with pipeline connection, connected to the power supply can work.
(2) The refrigeration unit of the miniature energy-saving cold storage adopts imported hermetic refrigeration compressor, and the main control components can also be used for foreign products, so the operation is safe and reliable, and the trouble-free operation time is long.
(3) micro energy-saving cold storage automatic control system using microcomputer control, temperature control is accurate, easy to operate, the unit has automatic and manual dual-position operation, with a variety of automatic protection devices, and is equipped with an electronic temperature display, convenient for the user to observe the temperature of the cold storage library.
(4) The miniature energy-saving cold storage unit adopts hot gas or electric heat defrosting method, which has short defrosting time and small temperature fluctuation during defrosting.
The most commonly used specifications for miniature energy-saving cold storage have two kinds: 90m3 and 120m3 volume, the building investment is generally 1.5~2.0 million yuan, according to the design points of the miniature energy-saving cold storage library constructed in the library, cooling speed, good insulation performance, cold storage library temperature fluctuation is small, the empty library is generally open 48 hours, the cold storage library temperature can be lowered from 20 ℃ to 0 ℃; the pre-cooling of the fruit pre-cooling and cooling stage, the equipment daily power consumption is generally 40 ~ 40%, the temperature is low. Equipment daily power consumption is generally 40 ~ 50 degrees, cold storage library temperature stabilization daily power consumption of only 7 ~ 8 degrees, northern regions in winter can be used in the natural cold source ventilation cooling, monthly power consumption is very low.
Maintenance of cold storage equipment
1, often check and confirm whether the power supply voltage meets the requirements, the voltage should be 380V ± 10% (three-phase four-wire). Cold storage equipment is not used for a long time, should be cut off from the cold storage of the total power supply, and to ensure that the cold storage equipment is not damp, not by the gray and other substances such as pollution.
2, the condenser on the refrigeration unit is easily stained, should be cleaned regularly according to the actual situation. To maintain good heat transfer. Good heat dissipation, cooling is good. Do not pile up debris around the refrigeration unit;
3, the electrical equipment of the cold storage equipment should be avoided moisture, so as not to leakage caused by electric shock accident.
4, cold storage door hinges, handles, door locks should be added regularly according to the actual situation of lubricating oil.
5, cold storage equipment, electrical equipment maintenance should be by electricians or know how to use electricity knowledge of the personnel to operate, any maintenance must cut off the power supply to ensure safety.
6, refrigeration machine in operation should avoid vibration, vibration in addition to increase mechanical wear and tear will also lead to the unit on the connecting tube loose or broken. Machine in the process of operation if found abnormal noise, should be stopped to check, remove and then run. Refrigeration compressor set of protective functions have been set in advance, no need to adjust.
7, regularly check the refrigeration unit of the connecting tube, valve parts on the connecting tube is firm, whether there is refrigerant leakage (general leakage will appear in the place of oil). The most practical way to check the leakage is: use a sponge or soft cloth dipped in detergent, rub the foam, and then evenly coated in the place to be checked for leakage, and observe for a few minutes. If there is a leak, bubbles will appear. Mark the place of leakage, and then do the fastening or gas welding treatment (by professional refrigeration staff for overhaul operation).
8, cold storage equipment on the top (top plate) should not be stacked debris, otherwise the cold storage library board will be deformed and affect the thermal insulation performance, and keep the cold storage around the channel unobstructed, only to ensure that the heat is good, refrigeration can be good. The location of the cold storage should be kept dry, clean, no flammable and explosive materials, to ensure that there is no hidden danger of safety. The evaporator should not be stacked in front of the items (reserved a certain gap), so as not to affect the cooling effect. 9, such as due to excessive air humidity, frost interval time is long, the library temperature setting is not normal, all of which will lead to the library evaporator on the frost layer thickening, the library temperature does not fall. At this time should be frost (defrost) processing. And timely observation, such as frost layer disappears immediately stop frost. Wait a moment and then start the equipment.
10, cold storage equipment, temperature, temperature difference and other parameters, these should be set according to the actual situation of the cold storage, can not arbitrarily change the parameters. Cold storage factory has been customized according to user requirements, to understand the technical parameters of the cold storage and then set the parameters on the controller.
11, the compressor should be avoided to start frequently, each downtime gap time should not be less than 6 minutes. Compressor sight oil mirror oil level drop or dirty, need to be added or replaced in a timely manner, can not be added to the wrong grade and long-term exposure to the air resulting in water content of unqualified freezer oil, otherwise it will cause high-temperature carbonization, low-temperature precipitation of wax, motor insulation is impaired, the system is difficult to return to the oil and other malfunctions. Often pay attention to the compressor shell, body and cylinder head temperature changes to determine whether the compressor is running normally. Refrigeration compressor does not need to be refueled under normal circumstances. If you determine the need for refueling, should be added by professionals to the compressor oil, refueling by professionals to develop, not blindly add.
12, regularly check whether the power supply voltage is normal (three-phase four-wire), check whether the protection function of the power supply main switch is normal and effective.
How to buy a suitable cold storage
Dear users, if you want to build a suitable cold storage, Kaijie refrigeration suggests that you consider the following aspects:
1, according to the tonnage of self-storage of goods, the amount of incoming and outgoing shipments per day and the size of the building to determine the size of the cold storage (length × width × height) to determine the specification of the size of the library door, the door opening direction. The installation environment of the cold storage should be clean, dry and ventilated.
2, according to the stored items, choose to determine the temperature of the library (fresh storage: +5 - 5 ℃, refrigerated freezing: 0 - 18 ℃, low-temperature storage: -18 - 30 ℃).
3, according to the characteristics of their own buildings and the local water supply, the choice of refrigeration refrigeration, generally air-cooled and water-cooled. (Refrigerator is air-cooled users only need to choose the placement can be, refrigerator is water-cooled users also need to configure the pool or deep well, circulating water piping and pumps, cooling tower placement).
I hope to help you, please adopt!