If it is found that the low temperature small refrigeration unit has run out of oil, analyzing the problem from the principle is basically related to its structure. Why does the low temperature small refrigeration unit run out of oil?

Some refrigerators on the market are made by mixing refrigerant oil with refrigerant. Due to the different density and weight of refrigerant oil and refrigerant, it is possible to use an oil separator to separate the unit refrigerant oil from the refrigerant, and then allow the refrigerant to return to the compressor through a full liquid evaporator. This new type of refrigeration effect is quite good, but the simple problem is that oil leakage may occur.

When the cooling water temperature is low, the degree of superheat during startup is not high, and then due to incomplete separation of the refrigerant, a mixture of refrigerant oil and refrigerant will appear. Together, they enter the heat exchanger, resulting in low pressure and even severe conditions that can lead to clogging of the expansion valve, making it impossible for a small low-temperature refrigeration unit to start.

What should we do? If it is found that there is a decrease in the classified oil level, the unit should be immediately switched to manual control mode, so that the compressor can be constrained by its energy, and the condensing pressure can be increased to always lower the low pressure alarm value of the unit to the allowable range. This can ensure that the unit is in a state where it will not be shut down and can still be started as much as possible.

If the above operations are carried out, it is found that the oil level of the low temperature small refrigeration unit is still very low, and the evaporator pressure is also very low, it is necessary to consider whether all the oil has gone into the evaporator. At this time, you can check the evaporator to see whether there is a lot of white foam rolling in the liquid crystal. If there is, it means that the oil is in the evaporator.

Therefore, it is necessary to conduct regular monitoring on small low-temperature refrigeration units to prevent various problems in the process of application.

No matter how good a product is, there are times when it fails. How can you quickly determine the failure and keep the high-precision water chiller in a good working state.

1. In high temperature experiments, if the temperature change does not reach the experimental temperature value, you can check the electrical system and eliminate faults one by one. If the temperature rises slowly, it is necessary to check the air circulation system to see if the regulating damper of the air circulation is opened normally. Otherwise, it is necessary to check whether the motor of the air circulation operates normally. If the temperature overshoot is severe, it is necessary to set the setting parameters. If the temperature rises directly and the temperature is protected against overheating, the controller fails and the control instrument must be replaced.

2. If the low temperature does not meet the experimental indicators, then you should observe the temperature change, whether the temperature drops slowly or there is a tendency for the temperature to rise after reaching a certain value. Consider whether there is a fault in the refrigeration system, and ask the manufacturer’s professional personnel for maintenance. This phenomenon is caused by the poor operating environment of the equipment. The ambient temperature and location of the equipment (the distance from the back of the box to the wall) should meet the requirements (specified in the equipment operation instructions).

3. High precision water chiller with slow or no temperature rise: Check whether the heating system has faults, such as whether the heating pipe is broken, whether the heating pipe wiring is loose, whether the control instrument is burned out, and whether the circuit is open. No humidity: first check whether there is a water shortage, then check whether the humidifier is normal, and then check the electrical control part. Only high temperature, no low temperature: The compressor works normally, which may be due to a lack of refrigerant in the compressor, a blockage in the radiator, resulting in poor heat dissipation, or a blockage or leakage in the pipeline. As long as there is a targeted troubleshooting, it is sufficient. Uneven temperature and humidity in the box: It may be a problem with the mixing fan. It is necessary to check the working condition of the fan first. For example, whether there is noise, whether the motor is burned, and whether the bearing is short of oil.

In the chemical synthesis of various reactions such as nitrification, oxidation, hydrogenation, reduction, diazotization, addition, esterification, condensation, hydrolysis, etc., the temperature should be strictly controlled to prevent impact or explosion. The temperature of heating, reflux, cooling, distillation, recrystallization, filtration, etc. should also be controlled, otherwise it is very easy to burst.

For industrial production, process operability generally involves industrial equipment and process operation itself. Laboratory temperature control: oil bath, water bath, low-temperature reaction device, liquid nitrogen, etc.

The heat transfer medium used for most reactions in most plants is water or steam, that is, at – 20 ℃~110 ℃. If the temperature required by the process is higher than 110 ℃, it needs to be replaced with heat transfer oil for heating, and the whole equipment also needs to be replaced. It is necessary to measure whether the cost can be accepted; In the case of low temperature, most ice salt baths are used for cooling. The lower limit is – 30 ℃, but the actual temperature can only reach – 20 ℃. If the temperature is required to be lower, the deep cooling method must be adopted, and the equipment and media need to be replaced.

Very high and very low temperatures will increase the process cost, so when selecting the route, try to choose those synthesis processes with the temperature between – 20 ℃ and 110 ℃.

The precision of temperature control in the laboratory can reach ± 1 °. Temperature control under industrial conditions is not as convenient as that in the laboratory. Generally, temperature control is achieved through continuous exchange of cold and hot water. Some processes may indeed require rapid heating or cooling, which can be achieved. Higher temperature heat transfer medium (such as water vapor) or lower temperature cooling medium (such as ice salt water) can be used for heating, but this method is difficult to grasp the accuracy of temperature control.

Our LNEYA refrigeration and heating equipment has a very wide temperature control range from – 120 ℃ to 350 ℃, which is suitable for the constant temperature control needs of most enterprises. The temperature control accuracy can reach ± 0.5 ℃, and the refrigeration power can be supplied from 0.5kW to 1200kW. Typical applications: dynamic constant temperature control of cold and heat sources in high-pressure reactor, dynamic constant temperature control of cold and heat sources in double-glass reactor, dynamic constant temperature control of cold and heat sources in double-layer reactor, and constant temperature control of cold and heat sources in microchannel reactor; Small constant temperature control system, temperature control of distillation system, low temperature and high temperature aging test of materials, constant temperature control of combined chemical cold source and heat source, cooling and heating of semiconductor equipment, and constant temperature control of vacuum chamber cooling and heating. With magnetic drive pump, there is no shaft seal leakage problem. High-temperature cooling technology can directly cool from 300 ℃ [because only the heat transfer medium in the expansion chamber contacts with oxygen in the air (and the temperature of the expansion tank is between normal temperature and 60 ℃), which can reduce the risk of heat transfer medium being oxidized and absorbing water in the air.

The heating system is a fluid cooling and heating temperature control equipment commonly used in pharmaceutical, chemical, and components. It can conduct dynamic temperature control of cooling and heating for different temperature ranges. It is widely used in industrial production and is applicable to the reaction of various phase materials. Different types of mixing and heat transfer devices are equipped. So how much do you know about the control mode of heating system?

1. The heating system selects the reactor temperature control system through the cooling coil, which is equipped with cooling inlet and outlet, cooling water, refrigerant and external circulating coolant.

2. Regarding the orientation of the device for cooling coil of the heating system, the device is usually located inside the reactor to reduce the temperature of the material in the reaction, and can be placed outside when the material viscosity is high or the coil needs mixing mode; When the medium is used as a heating source, the cooling coil can be placed in the medium. The heating of the resistance wire depends on the specific situation, but the heating effect and cooling effect should be considered.

3. It can be operated intermittently or continuously or semi-continuously. It can be operated by a single kettle or by multiple kettles in series. It has wide application, flexible operation and easy control of concentration. It is usually composed of kettle body, heat exchange device, mixer and heat transfer device.

4. The operation process is to operate on the display screen of the equipment, set the temperature range, and then operate the equipment itself, which provides convenience and efficiency for production and processing.

5. The main function is to control the temperature of the reaction kettle, improve the heat transfer efficiency, meet the strict requirements of high process standards, close cycle heating, small heat loss, and wide range of use.

6. In the chemical industry, the flow of equipment can be customized. According to the user’s requirements, the reasonable matching between low temperature and refrigeration capacity, lo

w temperature and container capacity can meet the actual needs of different users.

When the user is running the cooling and heating cycle of the reactor temperature control system, he needs to have a clear understanding of the operation and operating principle of the equipment in order to effectively operate the reactor temperature control system. So how much do you know about the operation?

The reliability of the operation of the reactor refrigeration heating cycle temperature control system usually depends on some seemingly insignificant factors, such as the need to confirm the operating temperature range of the specific heat transfer oil. Some temperature control equipment only uses one heat transfer medium throughout the working temperature range, which avoids the trouble caused by pausing the experiment to replace the heat transfer oil during the experiment, improves the fluency of the whole experiment, and saves time and cost. Therefore, experimenters can conduct a series of tests under low and high temperature conditions without draining the heat transfer oil, cleaning the reactor to heat the temperature controller, and changing to different heat transfer oils. This greatly improves the flexibility of the reactor refrigeration and heating cycle temperature control system, and also saves a certain amount of time.

A good reactor cooling and heating cycle temperature control system should be able to work stably even in a high temperature environment. There will be a certain gap between the actual working ambient temperature of the reactor constant temperature equipment and the calculated ambient temperature, even if it is a supporting small test Equipment will also have more requirements for temperature control.

A high-precision reactor refrigeration heating cycle temperature control system is very important. Its electronic control module can continuously monitor and control the internal materials of the reactor and when the heat transfer oil of the equipment changes, the reactor constant temperature equipment system can quickly adjust the variable to the set point without overshooting. In order to ensure the stability of the temperature control system, precise control is required, and the accurate electronic control module has a great influence on the stability of the reactor constant temperature equipment.

Various factors may occur during the operation of the reaction kettle refrigeration heating cycle temperature control system. In order to better use the equipment, the operator needs to have a certain understanding of its installation and use.

The explosion-proof water chiller can run stably and reliably for a long time, and at the same time provide reliable cooling effect, stable work and long life. The microcomputer full-function control panel is simple and fast, and the interface is friendly and more humanized.

1. The equipment is a fully enclosed liquid circulation. There is no oil mist at high temperature, and it will not absorb water vapor at low temperature. The heat transfer oil will not contact with the air, so as to prevent the oxidation and browning of the heat transfer oil and prolong the service life of the heat transfer oil. Closed heating circulator It can also prevent the operator from being burned by misoperation, prevent the oil mist generated during heating from being inhaled into the body, and reduce the risk of accidents.
2. It is a cyclic process in which the refrigerant moves heat from a low-temperature object to a high-temperature object, thereby cooling the object below the ambient temperature and maintaining this low temperature. This process is realized by a refrigeration device.
3. Utilizing the characteristic that the refrigerant has different solubility at different temperatures in the solution, the refrigerant is absorbed by the absorbent (solvent) at a lower temperature and pressure, and at the same time it is absorbed by the absorbent at a higher temperature and pressure. Evaporate in the solution to complete the cycle to achieve the purpose of refrigeration.
4. Since it is not easy to achieve constant air temperature heating and constant temperature heat removal, it cannot operate in reverse cycle. In the compressed air refrigeration cycle, two constant pressure processes are used to replace the two constant temperature processes of the reverse cycle, so it can be regarded as a reverse cycle.

In addition to the product quality of explosion-proof water chillers in the petrochemical industry, purchasing reasonable and formal equipment is the first step to ensure that the equipment plays a good role. For example, when purchasing, the user needs to pay attention to whether the upper and lower limits of temperature, ignition point, viscosity, freezing point, etc. meet the requirements, and whether it is suitable for the use of the internal pipeline of the instrument; when selecting the heat medium pipe of the equipment, the length should be as short as possible, and the diameter as large as possible.

Generally, small or medium-sized heating and cooling circulators are used in the laboratory. It is applicable to connect reactors in pharmaceutical, chemical and laboratory industries for refrigeration and heating reactions, especially the heating and cooling circulator series in medium-sized laboratories. Its main functions are to control the temperature rise and fall of glass reactors, metal reactors and biological reactors.

The heating and cooling circulator of the medium-sized laboratory is designed to be fully closed, which is used for constant temperature control of external loads. It is designed to be closed, and will not produce oil mist and pungent smell to volatilize into the environment at high temperature, and will not absorb impurities and moisture in the ambient air at low temperature. Only the heat transfer medium is involved in the circulation, and the temperature of the expansion tank is always kept at a low temperature, It avoids many problems such as deterioration of circulating medium and unfriendly environment caused by air entering the circulating system.

Medium-sized laboratory heating and cooling circulator is suitable for the control of heat demand and heat release process in the reaction process. Linear control of the temperature of the materials in the kettle can select the program control mode, and the temperature difference between the heat transfer medium and materials can also be set. The fully closed pipeline design is adopted to reduce the demand for heat transfer fluid, improve the heat utilization rate of the system, and achieve rapid temperature rise and fall. The heat conduction medium in the expansion vessel does not participate in the circulation, which can reduce the risk of moisture absorption and volatilization of the heat conduction medium during operation.

The heating and cooling circulator system of the medium-sized laboratory is equipped with an expansion vessel. The expansion vessel and the liquid circulation system are adiabatic and do not participate in the liquid phase circulation, but are mechanically connected. The medium in the expansion vessel remains at room temperature regardless of the temperature of the circulating liquid. Since the whole liquid circulation is a closed system, there is no water vapor absorption at low temperature and no oil mist generation at high temperature.

The heating and cooling circulator in the medium-sized laboratory is equipped with a heating and cooling integrated container, which has a large heat exchange area, a fast heating and cooling rate, and a relatively small demand for heat transfer oil. It can realize continuous temperature rise and fall. It adopts the compressor technology under high temperature and high pressure, which can directly start the compressor refrigeration from 350 ℃, greatly providing cooling rate, and saving test time and energy.