Industrial air cooler adopting four-way valve system for defrosting

Abstract

An industrial air cooler adopting a four-way valve system for defrosting comprises a compressor, an oil separator, a filter, a condenser, an evaporator, a centrifugal fan and an air outlet which are sequentially connected, and is characterized in that a four-way valve is arranged between the filter and the condenser, and four ports of the four-way valve are connected with the filter, the condenser, the compressor and the evaporator respectively; and an expansion valve is connected between the condenser and the evaporator. According to the air cooler, the four-way valve and the expansion valve are arranged, the conversion period and the defrosting period of the four-way valve can be set according to the operation frosting rule of equipment, frost layers on the evaporator can be rapidly removed, and therefore the working efficiency of the air cooler is guaranteed.

Description

Technical Field

[0001] This utility model relates to a cold air blower, and more particularly to an industrial cold air blower that uses a four-way valve system for defrosting. Background Technology

[0002] Currently, evaporative air coolers with cooling functions can achieve outlet air temperatures below zero degrees Celsius. As the refrigerant evaporation temperature decreases, the outlet air temperature will further decrease. Under normal operating conditions, if the unit runs for a long time and the refrigerant evaporation temperature is too low, and the refrigerant evaporation is insufficient, a frost layer will form on the evaporator fins. The frost layer forms by progressing from both sides of the evaporator towards the center, and the formation rate increases in the later stages, which will greatly affect the cooling effect and limit the minimum outlet air temperature of the evaporative air cooler. Evaporator icing will also prevent the liquid refrigerant from completely vaporizing, causing liquid to return to the compressor and indirectly leading to liquid slugging damage to the compressor. Utility Model Content

[0003] The purpose of this invention is to provide an industrial air cooler that uses a four-way valve system for defrosting, addressing the current state of the technology.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] An industrial air cooler employing a four-way valve system for defrosting includes a compressor, an oil separator, a filter, a condenser, an evaporator, a centrifugal fan, and an air outlet connected in sequence. The air cooler is characterized by: a four-way valve being provided between the filter and the condenser, with its four ports respectively connected to the filter, the condenser, the compressor, and the evaporator; and an expansion valve being connected between the condenser and the evaporator.

[0006] Preferably, the expansion valve is a Danfoss TEX-2068Z3209 externally balanced thermostatic expansion valve, connected between the condenser and evaporator using oxy-acetylene welding. Its function is to throttle the high-pressure, medium-temperature liquid refrigerant, causing it to vaporize after throttling. The thermostatic expansion valve has a temperature sensing bulb fixed to the pipeline between the evaporator and the four-way valve. Its function is to provide feedback on the refrigerant evaporation temperature, enabling the expansion valve to better regulate the refrigerant flow and enhance refrigeration efficiency.

[0007] This utility model is equipped with a four-way valve and an expansion valve. The switching cycle of the four-way valve and the defrosting cycle can be set according to the frosting pattern of the equipment operation, which can quickly remove the frost layer on the evaporator, thereby ensuring the working efficiency of the air cooler. Attached Figure Description

[0008] Figure 1 This is a simplified structural diagram of the refrigeration mode of this utility model;

[0009] Figure 2 This is a simplified structural diagram of the defrosting mode of this utility model;

[0010] Figure 3 This is a schematic diagram of an expansion valve. Detailed Implementation

[0011] The present invention will now be described in further detail with reference to the accompanying drawings.

[0012] Reference Figure 1 and Figure 2 As shown, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor passes through the oil separator, dryer filter, and four-way valve, then sequentially enters the condenser and thermostatic expansion valve. After throttling, it enters the evaporator and returns to the compressor via the four-way valve, completing one refrigeration cycle. When defrosting is required, the high-temperature, high-pressure refrigerant is discharged from the compressor, passes through the oil separator, dryer filter, and four-way valve, and directly enters the evaporator. It then passes through the expansion valve, condenser, and four-way valve before returning to the compressor. During this process, the evaporator temperature rises rapidly, and the frost layer melts quickly. By setting the four-way valve switching cycle and defrosting cycle according to the equipment's frosting pattern, the frost layer on the evaporator can be quickly removed.

[0013] like Figure 3 As shown, the main components of an externally balanced thermostatic expansion valve are: Temperature sensing bulb (P1): Charged with the same refrigerant as the system, installed on the evaporator outlet pipe section, it senses the refrigerant temperature and converts it into a pressure signal. Diaphragm: Pressure from the temperature sensing bulb (P1) is applied above, and the evaporator outlet pressure (P2) is introduced below through the balance pipe. The diaphragm displacement is determined by the balance of three forces: P1 = P2 + spring force (P3). Spring (P3): The preload is set by the adjusting screw, determining the static superheat (typically 4°C). Balance pipe (P2): Directly connected to the top of the evaporator outlet, it transmits the actual evaporation pressure, eliminating the influence of internal evaporator resistance on the pressure signal. The valve core and throttling orifice adjust the opening according to the diaphragm displacement, controlling the refrigerant flow.

[0014] Working principle:

[0015] 1. Equilibrium of three forces

[0016] When the evaporator heat load changes, the outlet temperature changes, and the pressure (P1) of the temperature sensing bulb changes. The pressure (P2) below the diaphragm is taken directly from the evaporator outlet through the balance tube, not from inside the valve body. If P1 > P2 + P3, the diaphragm moves downward, the valve core opening increases, and the liquid supply increases; conversely, it decreases the liquid supply.

[0017] 2. Superheat control

[0018] By dynamically adjusting the opening degree, the superheat at the evaporator outlet is kept stable, avoiding liquid slugging (liquid refrigerant backflow) or excessive superheat.

[0019] This invention can periodically remove the frost layer, which helps to release cold energy; effectively prevents damage to the compressor from liquid slugging; active defrosting takes less time than natural defrosting, improving efficiency; and the water collection tray can also prevent moisture from appearing around the equipment.

[0020] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of this utility model. The technical scope of this utility model is not limited to the contents of the specification. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An industrial air cooler employing a four-way valve system for defrosting, comprising a compressor, an oil separator, a filter, a condenser, an evaporator, a centrifugal fan, and an air outlet connected in sequence, characterized in that: A four-way valve is installed between the filter and the condenser, with its four ports connected to the filter, condenser, compressor, and evaporator, respectively. An expansion valve connects the condenser and the evaporator. The gaseous refrigerant discharged from the compressor passes through the oil separator, dryer filter, and four-way valve, then enters the condenser and the thermostatic expansion valve in sequence. After throttling, it enters the evaporator and returns to the compressor through the four-way valve, completing one refrigeration cycle. When defrosting is required, the refrigerant is discharged from the compressor, passes through the oil separator, dryer filter, and four-way valve, then directly enters the evaporator, and finally returns to the compressor after passing through the expansion valve, condenser, and four-way valve.

2. An industrial air cooler employing a four-way valve system for defrosting as described in claim 1, characterized in that: The expansion valve is an externally balanced thermostatic expansion valve.

Images