Industrial air cooler adopting electric heating device
By introducing an electric heating device and an expansion valve into the industrial air cooler, and using an electric heating wire to periodically melt the frost layer, the problems of frost layer affecting the cooling effect and compressor liquid slugging are solved, achieving a highly efficient and low-energy defrosting method.
Patent Information
- Application Number
- CN202520623233.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2035-04-03
AI Technical Summary
Existing industrial air coolers are prone to frost formation when operating at low temperatures, which affects the cooling effect and may cause liquid slugging damage to the compressor. Traditional defrosting methods are energy-intensive and have a slow response time.
The system employs a combination of an electric heating element and an expansion valve. The electric heating wire periodically melts the frost layer on the evaporator surface, and the refrigerant flow is regulated by a temperature sensing bulb and a thermal expansion valve to improve refrigeration efficiency.
It enables rapid melting of frost, prevents liquid slugging in the compressor, improves refrigeration efficiency, reduces defrosting time, and lowers energy consumption.
Smart Images
Figure CN223663536U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a cold -blast machine especially an industrial cold -blast machine adopting electric heating device. BACKGROUND
[0002] Industrial cold -blast machine is widely used in equipment cooling, material cooling, food processing and other fields, the cold -blast machine with refrigeration function on the market can reach zero degree below the outlet temperature, with the refrigerant evaporation temperature reduction, the outlet temperature will be further lower. Under general working conditions, such as unit long time operation and refrigerant evaporation temperature is too low, when refrigerant evaporation is not sufficient, frost layer will form on the evaporator fin, and the formation of frost layer shows that: from the both sides of the evaporator to the middle part progression, and the later the formation speed is faster, which will greatly affect the refrigeration effect, resulting in the lowest outlet temperature of the cold -blast machine is limited. Evaporator icing also makes liquid refrigerant unable to completely gasify, and liquid is returned to the compressor, which indirectly causes the compressor liquid damage. The traditional defrosting mode depends on manual timing operation or simple temperature control, and has problems such as high energy consumption and response lag. SUMMARY
[0003] The utility model discloses a kind of industrial cold -blast machines using electric heating device.
[0004] To achieve the above object, the utility model adopts the following technical scheme:
[0005] A kind of industrial cold -blast machine using electric heating device, including the compressor, condenser, liquid storage tank, dry filter, evaporator, centrifugal fan and air outlet connected in sequence, characterized by: expansion valve is connected between dry filter and evaporator;Electric heating device is equipped on evaporator.
[0006] Preferably, the electric heating device is a heating wire.
[0007] Preferably, the expansion valve uses Danfoss TEX-2068Z3209 type outer balanced thermal expansion valve, adopts oxy welding connection mode, and is connected between the dry filter and the evaporator. Its role is to throttle the high-pressure medium-temperature liquid refrigerant, and the refrigerant is gasified after throttling. The thermal expansion valve has a temperature sensing bag fixed on the pipeline between the evaporator and the compressor, which feeds back the refrigerant evaporation temperature to make the expansion valve better regulate the refrigerant flow and enhance the refrigeration efficiency.
[0008] The utility model sets up heating wire and expansion valve, can melt frost layer on the surface of evaporator quickly. Regularly removing frost layer helps to release cold energy;Effectively prevent compressor liquid damage;Active defrosting is shorter than natural defrosting time, improve efficiency. BRIEF DESCRIPTION OF DRAWINGS
[0009] Figure 1It is a structure schematic diagram of the utility model.
[0010] Figure 2 It is a principle diagram of the expansion valve. DETAILED DESCRIPTION
[0011] The utility model will be further explained in detail below with reference to the drawings.
[0012] Referring to Figure 1 As shown in the drawings, the electric heating wire is loaded in the evaporator, according to the frost formation law of the equipment, the electric heating wire starting period and defrosting period are set, and the frost layer is removed regularly.The refrigeration mode: the compressor works to discharge high-temperature and high-pressure liquid refrigerant, which passes through the condenser-liquid tank-dry filter-thermal expansion valve, then enters the evaporator after throttling, and then returns to the compressor from the evaporator to complete a refrigeration cycle. (In the refrigeration mode, the centrifugal fan blows out cold air). Defrosting mode: the refrigeration system is not started, the electric heating wire and the centrifugal fan are started, and the frost layer on the surface of the evaporator is quickly melted. A water pan is arranged at the bottom of the evaporator, and the water after defrosting is discharged through the water pipe on the water pan.
[0013] The electric heating wire is spirally wound along the gap of the evaporator fin, and the spacing is uniform (5-10cm is recommended), so as to avoid local overheating. The heating wire is pasted on the back of the evaporator (non-windward surface) by heat-conducting silica gel, and the length of each section is not more than 1m (to prevent excessive resistance). The heating wire is fixed on the evaporator frame by using a U-shaped clamp, and the spacing is ≤30cm to avoid loosening. The electric heating wire is separately connected with the temperature controller and separated from the compressor circuit to prevent interference. The temperature sensor (such as PT100) is pasted on the pipe wall of the evaporator outlet, which is 5-10cm away from the heating wire to avoid direct heating. The sensor is wrapped with aluminum foil tape to enhance the heat conductivity.
[0014] As Figure 2 shown: the main components of the outer balance type thermal expansion valve are: temperature sensing bag (P1): filled with the same refrigerant as the system, installed on the evaporator outlet pipe section, senses the refrigerant temperature and converts it into a pressure signal. Diaphragm: the upper part is subjected to the pressure of the temperature sensing bag (P1), and the lower part is introduced into the evaporator outlet pressure (P2) through the balance pipe. The displacement of the diaphragm is determined by the three-force balance: P1=P2+spring force (P3). Spring (P3): the pre-tightening force is set by adjusting the screw, which determines the static superheat degree (usually 4℃). Balance pipe (P2): directly connected to the top of the evaporator outlet, which transmits the real evaporation pressure and eliminates the influence of the internal resistance of the evaporator on the pressure signal. The valve core and the throttling port adjust the opening according to the displacement of the diaphragm to control the refrigerant flow.
[0015] Working principle of outer balance type thermal expansion valve:
[0016] 1. Three-force balance
[0017] When the evaporator heat load changes, the outlet temperature changes, and the temperature-sensing bag pressure (P1) changes. The pressure under the diaphragm (P2) is directly taken from the evaporator outlet through the balance pipe, rather than inside the valve body. If P1 > P2 + P3, the diaphragm moves downward, the valve core opening increases, and the liquid supply increases; otherwise, the liquid supply decreases.
[0018] 2. Superheat control
[0019] By dynamically adjusting the opening, the evaporator outlet superheat is maintained stable, avoiding liquid strike (liquid refrigerant backflow) or excessive superheat.
[0020] The utility model can help release cold energy by removing frost layer periodically; effectively prevent compressor liquid strike damage; active defrosting is shorter than natural defrosting, improving efficiency; setting water pan can also prevent water from appearing around the equipment.
[0021] The above content is further detailed in combination with specific preferred embodiments, and the technical scope of the utility model is not limited to the content in the specification. For ordinary skilled persons in the art, the above description can be improved or changed, and all these improvements and changes shall belong to the protection scope of the appended claims of the utility model.
Claims
1. An industrial air cooler using an electric heating device, comprising a compressor, a condenser, a liquid storage tank, a drying filter, an evaporator, a centrifugal fan and an air outlet connected in sequence, characterized in that: An expansion valve is connected between the drying filter and the evaporator; the evaporator is provided with an electric heating device; in the refrigeration mode, the compressor works to discharge high-temperature and high-pressure liquid refrigerant, which passes through the condenser-liquid tank-drying filter-thermal expansion valve, enters the evaporator after throttling, and then returns to the compressor from the evaporator to complete a refrigeration cycle; in the defrosting mode, the compressor is not started, the electric heating wire and the centrifugal fan are started to quickly melt the frost layer on the surface of the evaporator.
2. An industrial air cooler employing an electric heating device as claimed in claim 1, wherein: The electric heating device is an electric heating wire.
3. An industrial air cooler employing an electric heating device as claimed in claim 1, wherein: The expansion valve is an external balance type thermal expansion valve.
4. An industrial air cooler employing an electric heating device as claimed in claim 3, wherein: The external balance type thermal expansion valve adopts an oxywelding connection mode and is connected between the drying filter and the evaporator.