Analysis of energy-saving measures for aquatic cold storage in 2020

Analysis of energy-saving measures for aquatic cold storage in 2020

According to relevant information: a 5,000-ton cold storage facility consumes more than 8 million kilowatt-hours of electricity annually. The large-capacity ice-making, ice storage, freezing, cold storage, etc. unique to aquatic products freezing plants consume large amounts of annual electricity, which far exceeds the annual electricity consumption of general machinery and textile enterprises above the middle level. In terms of production costs, the proportion of power consumption is also very large. Therefore, how to reduce energy saving and electricity saving in all aspects of refrigeration plants, reduce floor space, and maximize economic benefits. In the market, today with fierce economic competition is particularly important. The following measures are often used in the design of okmarts.com in several aspects for reference.

Thickness of insulation layer of cold storage:

　　 The relevant information introduces the heat entering through the hot layer of the cold storage. It accounts for about 30% of the total cooking load of the cold storage, and the large single-story cold storage accounts for about 45%. The more heat that enters, the greater the cooling capacity of the refrigeration device, and the higher the power consumption of the device. If the insulation layer of the cold storage is thick, the investment will increase. The economic thickness of the thermal insulation layer should be considered from the cost of the thermal insulation layer, the sum of the cooling device and its operating cost and depreciation to the minimum. That is to determine through technical and economic analysis. It is advantageous to appropriately increase the thickness of the insulation layer during design to reduce the heat entering the cold storage.

　　The division of refrigeration process systems in aquatic products freezing plants;

To determine the design plan of a refrigeration process system is the preliminary idea proposed by the design position based on the requirements of the design task book. For general cold storage projects, the traditional approach is to divide the freezing system, cold storage system, ice making and ball storage system separately It is: a 33°C, a 28°C, and a 15°C system, which are commonly used and reasonable in the design of large and medium-sized refrigerators. For small and medium-sized aquatic products freezing plants, due to their production techniques, special silicon should be considered. Usually close to the fishing wharf, it is necessary to fill the fishing vessel with ice, so ice making has become an indispensable part of [industrial electrical appliances network-cnelc]. For a long time, block ice made from brine has the characteristics of safety and reliability, convenient operation, stable operating conditions of various equipment in the refrigeration system, and convenient storage and transportation of ice, so it has been popular with fishermen. And this kind of dysentery ice system is a gravity liquid supply system. For example, a certain ice making and ice storage system are both a 15Dc system, and both use a gravity liquid supply system or a ball storage system that uses an ammonia pump liquid supply system alone (when the ice storage capacity is not too large) ) Is obviously unreasonable and uneconomical. In view of the above situation, we divide the refrigeration process system into two systems: freezing, cold storage, and ice storage are combined into a 33"C system, and ice making is a 15℃ system. Freezing, cold storage, and ice storage are ammonia pump liquid supply systems; Brine ice is a gravity liquid supply system. In an evaporation system, three evaporators with different storage temperatures are connected: the temperature of the freezing compartment is ~23_. The temperature of the frozen storage compartment is 18℃～-23c, the temperature of the ice storage compartment一4℃. In terms of technical measures. As long as the constant pressure main valve or constant pressure electromagnetic main valve is installed on the return pipe of the evaporator at different temperatures to control different evaporation pressures I or control the storage temperature by controlling the evaporation area We generally use the latter, because it is desirable to integrate the ice storage into a 33C system when the cold consumption of the ice storage is not too large, which is desirable in terms of simplifying the refrigeration system, facilitating operation and management, and saving equipment investment. If In the future, the ice storage will need to be converted to dual-use storage, and the refrigeration process will be simpler. In the construction drawing of the "U.S. Aquatic Cold Storage Universal Design", we adopt this approach; the refrigeration process system of the aquatic refrigeration plant along the coast of Jacksonville This method is also used for the division of. After years of engineering practice, it has been proved that this division system is feasible and economical.

　　 Automatic control and safety protection of ammonia refrigeration equipment in aquatic products refrigeration plant:

When the heat load of the cold storage is constantly fluctuating, if the cold production capacity of the refrigeration device and the cold storage consumption of the cold storage continue to tend or reach a balance, the entire refrigeration device must be adjusted in a timely, accurate and reasonable manner to ensure the refrigeration device The automatic control of the refrigeration device under safe, accurate and reasonable conditions can replace many complicated manual operations, and its significance is that it can achieve the purpose of being safer, more accurate, and more economical than manual operations.

　　The cold storage adopts an automatic control system. In the refrigeration process, some automatic control instruments and automatic valves need to be added, and the capital investment is increased. Therefore, the design should determine the automation content of the production device according to the actual situation in order to achieve economical burying. It cannot be too complete to make the investment too expensive, nor too simple to ensure the safe and economic operation of the system. In short, it is necessary to be as accurate, reasonable and economical as possible under the conditions of ensuring the safe operation of the refrigeration device. Medium and small aquatic products freezing plants are generally built in relatively remote places, and the technical force is relatively thin. Therefore, we choose the second type of automatic control of refrigeration equipment, which contains system safety protection devices and local automatic control devices. The details are as follows:

　　(1) Safety protection device:

　　Ammonia compressor is a device that automatically shuts down such as excessively high discharge pressure, excessively high suction pressure, insufficient oil pressure difference, overload of the motor load, and permanent breakage. These protection devices can promptly issue an alarm before an accident occurs in the refrigeration device, or stop the compressor, and can indicate the type and location of the accident, so that the operator can check and deal with it in time.

　　(2) Automatic control of ammonia pump loop:

　　1) Automatic liquid supply in the low-pressure circulation storage tank: When the liquid level in the low-pressure circulation tank is lower than the set level, the float liquid level controller will automatically open the liquid supply solenoid valve to supply liquid into the tank.

　　 2) Automatic alarm when the liquid level of the low-pressure circulating liquid storage tank is super high. When the low-pressure identification skid has passed the set liquid level, it will automatically alarm.

　　3) The nitrogen pump automatically starts and stops: when the ammonia pump runs short of liquid (that is, when the ammonia pump is not running, the alarm signal is issued, and the pump is stopped after a delay to protect the ammonia pump from damage.

　　4) Automatic ammonia bypass: when the warehouse load changes. When the supply volume changes, the excess liquid is automatically bypassed back to the low-pressure circulating liquid storage tank.

　　5) Automatically prevent the backflow of ammonia liquid: When the ammonia pump stops running, prevent the backflow of liquid.

　　 The above-mentioned refrigeration process part of the automation equipment has achieved the expected effect after recent years of engineering practice.