Air-cooled Oil Cooler

Step 1: First, determine the system’s heat generation rate Q (W);the method is as follows.

1. Precise calculation of system heat generation:

Example: Consider a hydraulic system with a tank capacity of 100 L; the oil temperature rises from 20 °C to 45 °C within 15 minutes.

Q=T ×Coil× poil×V÷S

=25×1.88×0.915×100÷ (15×60)

=4780W

Q—-System heat output (W)

V—-Fuel tank capacity (L)

Poil—-Oil density (0.915 kg/L)

Coil—-Specific heat capacity (1.88 kJ/kg℃)

T—-Temperature rise (℃)

S—-Time (S)

2. If the above parameters cannot be provided, 30%–50% of the total hydraulic system power may be used as the required heat generation rate.

Example: For a hydraulic system where the total power of the oil pump motor is 11 kW, the heat generation range is 3300W-5500W.

Step 2: Determine the required target oil temperature T1 (°C)and the maximum ambient temperature of the equipment T2 (°C);

Step 3: Selection of the cooler’s cooling capacity q:

q=Q÷ (T1-T2)×δ

δ is the correction factor.

20# Hydraulic Oil: 1

32# Hydraulic Oil: 1.4

46# Hydraulic Oil: 1.8

68# Hydraulic Oil: 2.5

1. Variable displacement pump installation method:
   Connect oil drain port of the variable displacement pump
   
2. Constant-Flow Pump Installation Method: Connect oil return port of the relief valve
   
3.  Independent Circulating Cooler Installation Method:
   

Cooler Pipeline Design Precautions

1. At low temperatures, the viscosity of oil-based fluids increases; under such low-temperature operating conditions, pressure peaks exceeding the allowable range may occur. Similarly, during transient high- flow events, pressure peaks exceeding the allowable range may also arise. Therefore, a bypass safety valve must be installed on the oil inlet pipeline to protect the cooler.
2. In hydraulic and lubrication systems, pressure peaks frequently occur; these peaks can be several times the maximum pressure peak value. These pressure peaks appear in the form of pulses and can only be recorded using an oscilloscope. Due to the extremely short duration of these peaks, conventional overload valves cannot respond in a timely manner, making them insufficient to mitigate pressure surges and pressure fluctuations within the system. Under such circumstances, for safety and reliability reasons, it is advisable to employ an independent circulating cooling circuit.
3. C.Safety flow precautions: The flow capacity varies depending on the oil grade; please refer to the Technical Parameters Table for specific details and ensure an appropriate safety margin is maintained.
4. D.Pressure precautions: Operating pressure refers to static pressure; however, during oil return conditions, the instantaneous pressure at the pressure relief event is dynamic pressure. When measured using a pressure gauge, the dynamic pressure must be multiplied by at least 4. The displayed surface pressure should be below 0.5 MPa. At this point, the pressure momentarily drops to zero – please observe carefully! One action, one pulse!
5. E.Piping precautions: ① The pipe diameter must not be reduced; this is particularly important for oil discharge pipelines.② Where possible, use direct outlets and avoid bending the oil pipes or employing high-pressure hoses to minimize backflow resistance. ③ As a general rule, the smaller the bending angle and the fewer the number of bends, the better.
6. F.It is not recommended to install an oil filter on the oil delivery pipeline; however, if installation is unavoidable, the filter’ s flow capacity must be taken into account, and a parallel bypass safety valve must be installed, with the maximum safety relief pressure not exceeding 0.2 MPa.

Cooler Installation Precautions

1. A.During installation, ensure that the distance between the air intake and outlet and any obstacles is sufficient to prevent poor air flow or inadequate ventilation. For specific dimensions, please refer to the specification sheet.
2. B.The installation foundation must be secure; the base should be reliably fastened to the foundation. When  installing connecting pipes, filters, sleeves, or other components, use a wrench to firmly secure the connected parts to prevent damage to the cooler. Since the joints are made of aluminum, apply appropriate torque during installation and removal to avoid twisting or deformation.
3. C.The oil outlet pipeline must not be smaller than the interface specification; for oil inlet and outlet pipelines, rubber hoses are recommended. The cooler should not be installed in pipelines subjected to pulsating pressure. A bypass safety valve must be connected in parallel to the oil inlet; the safety pressure should be set below 0.5 MPa.
4. D.If the operating voltage is three-phase AC power, observe the fan’s rotation direction after powering on. If the voltage is DC power, pay attention to the positive and negative terminals of the power supply. If the fan rotates  in the wrong direction, interchange any two of the three-phase AC power phases or swap the positive and negative terminals.
5. E.The power supply must be connected according to the wiring diagram and must be reliably grounded. A overload protection device compatible with the cooler’s operating current/voltage must be installed on the circuit.

Remarks

◆Cooling capacity refers to the cooling rate under the conditions of an ambient temperature of 35 °C, an oil temperature of 55 ° C, and the use of ISO VG20;

◆For other grades of engine oil, the flow rate and heat transfer capacity should be divided by a specific coefficient;

◆Our products are continuously being improved; the specific structural dimensions may differ from the parameters listed

◆The  parameter  table  lists  common  specifications  and  models;  however,  our  company  can  also  accommodate customized orders.

• Model		Cooling capacity q [W/℃]	Design flow[L /min]			Fan power [W[W]	Noise [dB(A)]	Interface dimensions
  			32#	46#	68#
  YLF1200T		11200	440	228	225	180×2	70	Flange DN65
  YLF1500T		1500	500	384	256	250×2	70	Flange DN65
  YLF2000T		2000	600	461	307	250×2	70	Flange DN65
  YLF2500T		2500	800	616	307	600×2	77	Flange DN65
  YLF3000T		3000	1000	770	307	780×2	79	Flange DN65

  YLF1200–3000T Model External Dimensions

  Model	A	B	C	D	E	F	G	H	I	J
  YLF1200T	1110	650	310	980	40	225	140	105	510	DN65
  YLF1500T	1250	710	320	1090	45	230	140	110	550	DN65
  YLF2000T	1400	760	320	1240	45	230	140	125	590	DN65
  YLF2500T	1600	860	330	1440	45	235	140	120	700	DN65
  YLF3000T	1700	920	340	1540	45	245	150	120	760	DN65

  

• YLF1200–3000T External Appearance Diagram

YLF50-200 Flow – Cooling Capacity Curv

YLF250-600 Flow – Cooling Capacity Curve

Remarks:

◆”Cooling capacity” refers to the amount of heat dissipated when the oil temperature exceeds the ambient temperature by 1 °C. This cooling capacity varies depending on the viscosity and flow rate of the oil.

◆The “Cooling Capacity” in the table refers to the “cooling capacity” measured under the conditions of an ambient temperature of 35 °C, an oil temperature of 55 °C, and the use of 20# hydraulic oil.

◆The higher the hydraulic oil grade, the weaker its “cooling capacity” becomes; generally, Grade 32 hydraulic oil should be divided by a correction factor of 1.4, while Grade 46 hydraulic oil should be divided by a correction factor of 1.8.

For Grade 68 hydraulic oil, divide the value by the correction factor of 2.5.

YLF900-1500 Flow – Cooling Capacity Curve

YLF2000-3000 Flow – Cooling Capacity Curve

Remarks:

◆”Cooling capacity” refers to the amount of heat dissipated when the oil temperature exceeds the ambient temperature by  1 °C. This cooling capacity varies depending on the viscosity and flow rate of the oil.

◆The “Cooling Capacity” in the table refers to the “cooling capacity” measured under the conditions of an ambient temperature of 35 °C, an oil temperature of 55 ° C, and the use of 20# hydraulic oil.

◆The higher the hydraulic oil grade, the weaker its “cooling capacity” becomes; generally, Grade 32 hydraulic oil should be divided by a correction factor of 1.4, Grade 46 hydraulic oil by a correction factor of 1.8, and Grade 68 hydraulic oil by a correction factor of 2.5.

AH Cooler Technical Specification Sheet  

AH Model Dimension Table

AH Cooler Technical Specification Sheet    

AH Model Dimension Table

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