Due to the development of RFID, GPS and telecommunications networks, cold chain logistics accounts for about 15% of the application of the Internet of Things. At present, the global cold chain market is relatively well developed in Europe, America and Japan. The food refrigerated transportation rate in Europe, the United States, Japan and other countries has reached 80% to 90%, and 98% of Japanese fruits and vegetables pass through the cold chain in the circulation process, and the loss rate of fruits and vegetables is controlled below 5%. The low-temperature logistics of vegetables and fruits in the United States is more typical. After the products are harvested from the field to the refrigerators of consumers, they have been circulating in a low-temperature environment. The loss rate of fruits and vegetables in the logistics link is only 1% to 2%.
What is cold chain logistics?
Cold chain logistics means that temperature-sensitive products are always in a prescribed low temperature environment during storage, transportation, and sales. To ensure food quality and reduce food loss. It was established with the advancement of science and technology and the development of refrigeration technology. It is a low-temperature logistics process based on refrigeration technology and refrigeration technology as a means.
The composition of cold chain logistics
Cold storage: One of the core components of cold chain logistics is the “cold storage”, which includes a constant temperature and humidity cold storage with precise requirements for the humidity and temperature of the stored items and a “modified atmosphere cold storage” that plays a role in air-conditioning preservation.
Cold chain transmission: at a certain temperature, through the use of required transmission machinery, utensils, etc., to achieve the sorting, picking and packaging of fresh agricultural products.
Cold chain loading and unloading: This is a very important and difficult step. When refrigerating and freezing items, the unloading vehicle and the unloading warehouse should be sealed to ensure that the temperature rise of the items during unloading is controlled within the allowable range. When the unloading operation is interrupted, the doors of the transportation equipment should be closed immediately to keep the refrigeration system in normal operation.
Cold chain transportation: This is an important link in cold chain logistics. The cost of cold chain transportation is relatively high, and it contains more complex refrigeration technology and monitoring technology, such as temperature and humidity sensors, refrigerators, temperature recorders, etc., cold chain transportation management contains more risks and uncertainties.
Products suitable for cold chain logistics
Primary agricultural products
Vegetables, fruits, meat, eggs, aquatic products, flower products.
Quick-frozen food, poultry, meat, aquatic products and other packaged cooked food, ice cream and dairy products, chocolate, fast food raw materials.
Medicine, so it is more demanding and more complicated than the general room temperature logistics system, and the construction investment is much larger, which is a huge system project.
Sensors for cold chain logistics
Applying the Internet of Things technology to the raw material procurement, product storage, transportation, sales and other links of cold chain logistics can implement intelligent monitoring of the entire process.
There are two important links in cold chain transportation:
1. How to maintain a temperature throughout the process
It is mainly composed of heat preservation materials, sealing materials and sealing technology. Different from general heat preservation technology, the heat preservation technology of cold chain transportation requires heat preservation materials to be light and thin, but also have good heat insulation effect. The sealing material is required to have a better sealing effect, and it is required that the heat preservation effect should be achieved as much as possible under the conditions of opening the carriage, handling, loading and unloading.
2. How to monitor the temperature throughout the process
Through the wireless temperature and humidity monitoring system, the cold chain vehicles are fully transparently monitored and managed. Such as usb temperature and humidity data logger, wifi temperature and humidity sensor, cooler box, etc. No wiring is required easy deployment, and flexible disassembly and assembly. Using digital temperature sensor, high precision and high reliability. GPS and AGPS dual positioning make the positioning more accurate. And there is an offline supplementary transmission mechanism to ensure the integrity of the data. It is the best choice for the cold chain transportation industry, especially for companies whose vehicles are not fixed. Wireless temperature and humidity recorders are their best choice.
The working method of the usb temperature and humidity recorder is very simple. The collected temperature and humidity are written into the memory of the recorder at regular intervals. When the transportation is completed, all point-to-point supply chain temperature data can be read at one time, and a static temperature change chart can be generated. , Simply complete the monitoring of temperature changes in the supply chain. Take the medicines that need temperature management in the supervision of hospital medicine cabinets as an example. The temperature and humidity recorder can be placed in the medicine cabinet, and the temperature changes can be checked by downloading data regularly, and the alarm will be issued in time when the temperature exceeds the set temperature to form an early warning function. . For another example, in the cold chain supply chain, the consignee hands the temperature recorder to the shipper in advance, and places the temperature recorder in the package when the consignor delivers the goods. When the goods arrive, the consignee uses the computer software Reading the data, the software automatically generates a static graph of temperature changes in the entire supply chain. If the temperature exceeds the preset specified temperature, the temperature recorder will make a corresponding record and read it out by the software, which can be queried according to time. The horizontal axis of the temperature static graph is time, and the vertical axis is temperature, so you can know exactly what time the temperature has changed, which is convenient for information tracing.