Danfoss Condensing Unit
Danfoss Condensing Unit

20 years’ history for designing and manufacturing Danfoss condensing unit supplier, commercial refrigeration solution provider.

Danfoss Condensing Unit Video Cover

Your Best Danfoss Compressor Condensing Unit Manufacturer

Miracle has been in manufacturing the Danfoss condensing unit field for over 20 years;

Miracle does not only provide the complete Danfoss condensing unit but also supply the related refrigeration parts to meet your demand;

Miracle has many types of appearance boxes for the Danfoss condensing units for you.

Danfoss Condensing Unit MIC Series S Type

MIC Series S type Danfoss condensing unit is Miracle Standard box type condensing unit with a Danfoss brand compressor, S Type means the side blowing type for appearance, normally used as an outdoor unit of air conditioning for small power.


Danfoss Condensing Unit MIC Series T Type

MIC series T type Danfoss condensing unit is the popular box type condensing unit for power than 7HP, T type means the top blowing appearance, this kind of Danfoss unit are widely used for Commercial Air conditioning project.

Danfoss Condensing Unit MID Series S Type

Danfoss condensing unit uses the Danfoss compressor MLM series and MLZ series for medium temperature application, the temperature range is from -20℃ to +5℃.MLM compressor is suitable for R22 refrigerant, MLZ compressor is suitable for R22, R134A, R404A, R407A, R448A, R452A, R449A, etc. S type also means side blowing appearance.



Danfoss Condensing Unit MID Series T Type

MID series Danfoss condensing unit is widely used for air conditioning, cold room, and where the cooling system needed, with Danfoss brand compressors and Top blowing appearance to meet your requirements.


Danfoss Condensing Unit MICN Series S Type

MICN series Danfoss condensing unit is the new type Danfoss box type condensing unit that Miracle designed, which saves space, more beautiful appearance, and convenient use. S type is for the small power with side blowing type.

Danfoss Condensing Unit MICN Series T Type

MICN series Danfoss condensing unit is our designed new type condensing unit, except the above S type, we also provide T type for top blowing for cooling power more than 7HP to meet your higher requirements.

Miracle is the one-stop supplier for Danfoss condensing unit, except the Danfoss condensing unit, below are the related parts that you may need for the unit.

Such as refrigeration check valve, expansion valve, refrigeration ball valve, refrigerant shut off valve, refrigeration oil separator, filter drier, suction accumulator, refrigeration solenoid valve.

For details info, contact our engineers for the support!

With the development of the market, Danfoss’s condensing unit personalized demand is strong. As a responsible enterprise, it is the mission of the enterprise to provide customers with personalized solutions.

Miracle has always been committed to providing customers with personalized solutions. Miracle can customize Danfoss condensers according to market needs. Boost your business and achieve a win-win situation

Danfoss Condenser Coil
Danfoss Condenser Coil

Welcome to visit Miracle factory to check the Danfoss condensing unit production procedure, and all the details you want to know about us!

Not only that, Miracle can supply you with more types of refrigeration units, including refrigeration unitswater-cooled condensing units, small refrigeration units, refrigeration condensing units, commercial refrigeration units, freezer condensing units. Send your inquiry now!

We are trying to show you more details about our condensing unit to let you know more about the products that you will get, the compressor, the condenser, the pressure vessel products, the refrigeration valves, the electric control box, etc.

Any details for any Danfoss condensing unit you want to know more about, just contact us!

Related Products

  • Bitzer Condensing Unit

    Bitzer units include Bitzer air-cooled units and Bitzer water-cooled units, which are mainly used in low- and medium-temperature cold storage such as food preservation and cold storage of meat products.

  • Copeland Condensing Unit

    Copeland Condensing units use Copeland scroll compressors. Small size, low noise, long service life, low failure rate, and wide application range. Mainly used for medium and high-temperature cold storage.

  • Danfoss Condensing Unit Cover

    Miracle serves the field of air conditioning installation. There is a variety of Danfoss condensing unit covers to choose from. More convenient way, more competitive price.

  • Danfoss Condensing Unit Pipe Connection Ring

    If you are engaged in the installation of Danfoss condensing units, you should consider the connection method of the Miracle Ring. Miracle Ring will greatly improve the installation of Danfoss condensing units. It is time to make changes.

Danfoss Commercial Condensing Unit Installation

Do you have concerns that welding has risks for leaking if the workers are not experienced?

Do you have the concern that welding is taking too long time for installation and cost much for labor costs?

Do you have the concern that someplace is not allowed to use fire during the installation process?

If your answer is yes, you need to listen to me carefully.

And here I want to recommend to you the solder-free connection method which is perfect to solve all of your above concerns once for all.

The solder-free connection also can be called no welding connection, you just need a lokring tool, lokring fitting, and sealing liquid to finish the connection very quickly.

We have a manual tool and an electric tool to meet your demands, you can check the videos for how to use the lokring tool to do the installation very well.

As you can see, it saves around 70%-80% time which is saving the labor cost, and it’s very easy to operate, some training, the junior workers can do it well.

Now you may concern about the sealing for solder-free connection, please kindly check our test video here.

Danfoss Commercial Condensing Unit Installation Related Products: Insulated Copper Pipe, Copper Y Joint, Air Conditioner Parts.

The testing pressure can be reached 30MPA.

And besides that, we do many tests before you get the lokring tool and fittings.

Such as the bursting test, vibration test, salt spray test, cold and hot alternate test(The low temperature can be reached -40℃-~-50℃, high temperature can be reached for 130℃).

It’s good enough no matter you want to use it on your Danfoss condensing unit installation or for refrigeration system or air conditioning system.

For more info, contact us directly.

Danfoss Condensing Unit Parts

When you have a refrigeration system project for a cold room or air conditioning system.

How to get a suitable condensing unit with good performance and save your time and money, that would be the most important thing you care about, right?

Here Miracle introduces Danfoss condensing unit for you, which is very efficient, and reliable. also very easy for installation, try to provide you a wonderful solution to make your business simple.

Please be noted that the Danfoss condensing unit we are talking about here is the air-cooled box type condensing unit.

Do you want to know what kind of refrigeration parts of the Danfoss condensing unit we are using?

Or do you have a demand for buying the good quality main refrigeration parts for cold room or air conditioning?

I think the answer is yes. Then you are very wise to find Miracle to be your partner. Let me explain a little about the refrigeration parts here.

Miracle is the complete refrigeration solution provider for over 20 years.

We are not only providing the Danfoss condensing unit but also providing all the parts for the Danfoss condensing unit.

Such as a Danfoss compressor, air-cooled condenser, axial fan motor, refrigeration valves, pressure vessel products, pressure controllers, oil gauge, and so on.

In addition, we also provide refrigeration tools for installation and maintenance.

Such as air conditioner tool, HVAC vacuum pump, HVAC flaring tool, AC bracket, AC pad, etc.

For those parts, we can provide the famous brand according to your demand, such as Danfoss.

Of course, you can use reliable Chinese brands parts, OEM is also available. For more detail please contact us now.

What is a Danfoss Condensing Unit Used For?

Danfoss condensing unit is a very popular type box type condensing unit, that is mainly designed for commercial refrigeration, includes cold rooms, air conditioning, etc.

In addition, it also can be used for home when you need a small cold room for keeping the goods, or when you need better air conditioning for many houses in your home.

How does the Danfoss condensing unit used for commercial refrigeration?

The most popular application is the cold storage project, such as the small cold storage for fruit and vegetables, for milk, for eggs, mini cold storage for fish and meat, all of these cold rooms are providing the food for our daily life.

We all know that most of the food can’t be kept for a long time in ambient temperature, especially in hot temperatures, but people do need them every day.

For fulfilling people’s demand that eating fresh food not considering the season, for gaining the economic benefits for you who want to run the business for selling food.

Or for you who you want to do the business for providing the cold room for people to rent, cold storage has an important role.

The cold room also is widely used for storing flowers, medicine, and so on.

The cold storage can be designed for a low temperature around -30℃ and a high temperature around +10℃.

Covers for Danfoss Condensing Unit

The function of the Danfoss condensing unit cover is simple, mainly used to protect the unit, increase the aesthetics, and be anti-theft.

On this ground, I provide different types of covers for the Danfoss condensing unit to make it safer, more beautiful.

As you can see in the above photo, we have wooden and steel material covers with different colors for your different demands.

The size for covers can be customized according to your Danfoss condensing unit, so as to the color.

For more choices and how to choose the most suitable covers for your Danfoss condensing unit, contact us to know more.

Danfoss Condensing Unit AC Condenser

Danfoss Unit Condenser

The condenser and evaporator have an important role in Danfoss condensing unit.

Its main function is to transfer the high temperature and high-pressure gas refrigerant to water or air to condensate to medium temperature and high-pressure liquid refrigerant.

So it is heat exchange equipment.

The condenser has 3 types: air-cooled condenser, water-cooled condenser, and evaporative condenser.

The Danfoss box-type condensing unit uses an air-cooled condenser.

The condenser is consists of aluminum fins, copper pipes, AC axial fan.

The aluminum fin is available for a standard smooth type, and it also can be blue fins.

The fin space can be standard, such as 4.5mm, 6mm, 9mm, 12mm, also it can be customized as requested.

The copper pipe also can be chosen for the internal thread tube to increase the heat transfer efficiency.

The fan motor is optional for different brands.

For specific info about the condenser and condenser coil.

Read more: the trend of internal thread copper pipe, design of internal thread copper tube.

Danfoss Condensing Unit Specifications

The Danfoss box-type condensing unit has a very compact design, which saves space, and it is very easy to install.

Its stable and good performance will save your work for maintenance and be very cost-effective.

See their detailed specifications in the following.

R22 MLM Series Note:

Danfoss condensing unit uses an MLM series compressor from 3HP to 15HP for R404A refrigerant.

The type of Danfoss compressors we use in this specifications chart are MLM021~MLM116.

Danfoss condensing units from model MID-S03MA to MID-S10MA are the side blowing box type, from MID-T03MA to MID-T15MA are top blowing box type.

R404A MLZ Series Note:

Danfoss condensing unit uses MLZ series compressor from 3HP to 15HP for R134A, R404A, R407A refrigerant, etc.

The type of Danfoss compressors we use in this specifications chart are MLZ021~MLZ116.

Danfoss condensing units from model MID-S03ZA to MID-S10ZA are the side blowing box type, from MID-T03ZA to MID-T15ZA are top blowing box type.

R404A MLZ Series Note:

Danfoss condensing unit uses MLZ series compressor from 2HP to 15HP for R134A, R404A, R407A refrigerant, etc.

The new type of Danfoss compressors we use in this specifications chart are MLZ015~MLZ116.

Danfoss condensing units from model MID-S02ZB to MID-S06ZB are the side blowing box type, from MID-S07ZB to MID-S15ZB are top blowing box type.

Can You Customize Danfoss Condensing Unit?

Can You Customize Danfoss Condensing Unit

Yes, of course. That’s our profession, we will calculate and design the suitable Danfoss condensing unit according to your project.

For the cold storage project, we will consider the site condition, the products you will store, the temperature required in the cold storage, the ambient temperature, how long time to achieve the temperature when the product enters the cold storage, etc.

So please contact our team when you have needs for Danfoss condensing unit, we shall provide you with a professional solution.

Can I Choose Another Compressor for the Danfoss Condensing Unit?

On this page, we want to show you more about the Danfoss condensing unit, you can check other pages for other brand condensing units, such as Copeland, or any brand you like, contact us directly.

After checking the above Danfoss condensing unit, you may want to ask:

Can you supply other brand condensing units except for the Danfoss condensing unit?

Yes, of course, no matter is an internationally famous brand or a Chinese brand.

Such as Maneurop compressor, Copeland compressor, Highly compressor, Bitzer compressor, Frascold compressor, Original scroll compressor, Original semi-hermetic compressors, etc.

There are also different types for a box with different refrigerants, R22 and R404 condensing units are all available.

Can You Provide the Condensing Unit Without a Danfoss Compressor?

Can You Provide the Condensing Unit Without a Danfoss Compressor

Yes, we can. If you are the distributor or you have a good way to get a Danfoss compressor, it’s good for you.

We will make the box, condenser, refrigeration parts, evaporator for you, you can install and finish it with a Danfoss compressor by yourself.

But for easy work and better performance, it’s better you order the complete Danfoss condensing unit from us.

Besides, we can also provide you with scroll units, semi-hermetic units, horizontal units, mini condensing units, freezer condensing units, etc. Contact us now.

Analysis of Liquid Start Technology of Danfoss Condensing Unit Compressor

Danfoss Condensing Unit Liquid Return

When the refrigerant that returns to the Danfoss condensing unit compressor is not a pure gas but contains liquid, the influence of liquid refrigerant on the compressor is negative.

If there is too much liquid, it may even cause liquid shock, even if there is no liquid shock, the wet compression also will cause the runaway of oil. There is also an influence on lubrication.

There is a high possibility that some of the refrigerant liquid will run into the lubricating oil pool of the Danfoss condensing unit compressor.

Depending on the design of the internal refrigerant channel in different Danfoss condensing unit compressors, the amount of liquid refrigerant returning to the oil pool will be different.

The difference in the material and force of all friction-acting surfaces have different requirements for lubrication, and the ultimate resistance to liquid backflow is different.

The following figure takes Danfoss’s 10HP scroll compressor and 15Hp Danfoss condensing unit scroll compressor as examples to introduce the ability of the two compressors to resist liquid reflux.

Danfoss condensing unit compressor 10HP VS Danfoss compressor 15HP

The suction port of the 10Hp Danfoss condensing unit compressor is located on the upper part of the stator coil of the motor.

When the sucked refrigerant enters the Danfoss condensing unit compressor in a mixed form of gas and liquid, part of the liquid enters the compression chamber directly with the gas, and the remaining little liquid has no time to completely gas, it will form the liquid compression of the Danfoss compressor.

The Danfoss condensing unit scroll compressor has a flexible design, which can separate the scrolls and bypass the liquid to form self-protection to prevent liquid compression from destroying the scroll wall.

The other part of the liquid will be separated from the gas and will run down along the gap between the rotor, stator, and casing.

During the liquid return process, the heat of the motor will evaporate into gas and the lubricating oil will fall back into the oil pool to achieve the separation of liquid and lubricating oil restarts a new cycle.

Due to the different heights of the suction port of the 15Hp Danfoss condensing unit compressor, after the refrigerant is sucked into the compressor, it cannot be directly sucked into the compression chamber.

However, no matter what type of refrigerant is sucked, it will pass through the surface of the oil pool and move upward from the gap between the stator and rotor of the motor.

Finally, it enters the compression chamber through the bearing bracket; in this process, the gas, liquid, and lubricating oil in the refrigerant will be separated, the liquid will be evaporated, and the lubricating oil will drip into the oil pool and restart the cycle. Only gas will enter the compression chamber upwards.

Regardless of 10Hp or 15Hp Danfoss condensing unit scroll compressor, no matter how reasonable the structural design is, there is a possibility that the sucked refrigerant contains liquid and will enter the oil pool with the operation of the Danfoss condensing unit compressor, dissolve with the lubricating oil, and dilute Lubricating oil will eventually cause the decreasing of the viscosity of the lubricating oil, and the lubrication effect will be greatly reduced.

This will cause the main bearing of the Danfoss condensing unit compressor to wear due to the decreased lubrication effect, and eventually may cause the shaft to be hung and even the motor to burn.

Danfoss condensing unit compressor has avoided this as much as possible from the structural design.

The path of the refrigerant to the oil sump is specially designed to separate and evaporate the liquid. At the same time, the most important thing is to update the bearing material.

The series of Danfoss condensing unit scroll compressors use lead-free Teflon bearings or carbon bearings, which can withstand boundary lubrication conditions and even dry lubrication.

In the cold storage design, the measures to prevent liquid back phenomenon are mainly in system design, which can include the following aspects:

A. Install an accumulator and reasonably design the oil return hole.

B. Effective and timely defrosting function.

C. Reasonably match the heat exchange capacity of the evaporator, especially for the capacity of the cooler and the exhaust pipe in the cold storage.

D.Reasonable selection of thermal expansion valve, especially for applications with large fluctuations in load changes.

Danfoss Condensing Unit Start With Liquid

First of all, let’s define what is called starting with liquid.

When the Danfoss condensing unit is stopped, there is refrigerant liquid in the compressor shell.

The next time the compressor is started, the refrigerant liquid will damage the lubrication of the compressor.

Starting the Danfoss condensing unit compressor with refrigerant liquid is called start with liquid.

Then let’s take a look at the process of starting the Danfoss condensing unit compressor with liquid and how the liquid shock destroys the compressor:

When refrigerant liquid appears in the Danfoss condensing unit compressor shell, the liquid tends to stay at the bottom of the compressor and mix with the lubricating oil.

Lubricating oil and refrigerant generally dissolve each other. The solubility is related to temperature, additives, and many other conditions.

After the oil and refrigerant are mixed, the characteristics of the lubricating oil will change.

The most obvious change is that the dynamic viscosity will decrease, which will directly affect the lubrication effect.

When the Danfoss condensing unit compressor is restarted, the pressure in the Danfoss condensing unit compressor will be decreasing sharply, and it will be as low as the saturation pressure of the refrigerant at the current temperature, which will cause the refrigerant liquid in the lubricating oil to evaporate rapidly, boil, and produce a lot of foam.

The lubricating oil passage in the Danfoss condensing unit compressor is shown in the figure below. Generally, there are 4 parts inside the Danfoss condensing unit compressor that require oil lubrication, the lower bearing, the main bearing, the upper bearing, and the scroll.

The lower bearing is very close to the oil sump, and even the lower bearing of some compressors is designed to be immersed in the oil sump (such as Danfoss Danfoss condensing unit compressor Performer H and M series compressors), so in general, the lower bearing is the easiest part to get oil, there is no need to worry about lubrication problems;

The oil of the main bearing and the upper bearing is thrown up by the centrifugal force generated by the eccentric hole inside the crankshaft when the crankshaft is running.

If a large amount of foam is generated, the foam will block the eccentric hole where the lubricating oil rises, and it will also clean away the oil film on the original action surface.

This will make the friction surface rub without sufficient lubrication, which will cause the cylinder to hold the shaft in a serious way.

The dynamic bearing is the most affected part by the liquid start because this part has the highest position and the most difficult to obtain lubricating oil.

The moving bearing will be the first part to wear and eventually cause the breaking of the Danfoss condensing unit compressor.

Danfoss condensing unit compressor lubricant duct design

Starting With Liquid Reasons of The Danfoss Condensing Unit.

In a normally Danfoss condensing unit operating system, there should be no refrigerant liquid in the compressor, but at the moment when the unit is shut down, the compressor shell is the lowest pressure point of the entire system, and the high-pressure side is still high.

The system pressure needs to be balanced, and a lot of liquid refrigerants will continue to flow under the action of the pressure difference.

After the evaporator stops working, there is no heat input, and the refrigerant will migrate into the compressor shell in liquid form.

On the other hand, after shutdown, the refrigerant in the unit must be in a gas-liquid mixed state, and the liquid will migrate to a lower location.

In a closed environment, the liquid is also easy to collect in a place with low temperatures, where the low-pressure side of the compressor is located.

Normally the temperature is not high at the low-pressure side of the compressor, which will further increase the possibility of liquid refrigerant accumulation.

The measures to prevent refrigerant migration from starting with liquid.

A: Install the liquid pipe solenoid valve. After the unit stops, close the solenoid valve at the same time to trap most of the refrigerant liquid on the high-pressure side, which greatly reduces the possibility of starting with liquid.

B: Install the compressor electric heating belt.

After the compressor stops, the electric heating belt supplies power to heat the oil pool, maintain the heat input of the compressor, maintain the high temperature of the compressor oil pool, and evaporate the refrigerant liquid in the oil pool.

Avoid the influence of liquid foam at the next start.

C: The return air pipeline is designed with an inverted U-shaped bend to protect the Danfoss condensing unit compressor.

Because there is a height difference between the evaporator and the compressor after the condensing unit shutdown, the liquid in the evaporator will transfer to the compressor due to its own gravity, and the evaporator will runs in advance before the unit restarts next time.

When the evaporator runs, it will evaporate the liquid refrigerants into gas to ensure the safety of the compressor.

D: Install a suction accumulator. The accumulator is one of the most critical parts that affect the oil return.

It is generally installed between the gas return port and the Danfoss condensing unit compressor.

The accumulator has two key indicators, the oil return hole, and the balance hole. It is necessary to select or design a suitable accumulator according to the needs of your own system.

The Danfoss Condensing Unit Main Reasons for Liquid Hammer Are As Follows:

A: At the installation site of the Danfoss condensing unit, due to the lack of experience of the installer, after the vacuum is completed, the refrigerant is directly charged at the suction and exhaust ports of the compressor (the unit used in the cold storage has an angle valve here), and after charging, start the unit directly and causes liquid shock.

B: During the commissioning stage and even the stable operation stage of the Danfoss condensing unit, due to the problem of end matching, valve selection, abnormal evaporation side, etc., the unit has a large amount of liquid return in a short time, and finally causes liquid shock.

C. When the Danfoss condensing unit is shut down, the refrigerant migrates too much, and finally, the compression cavity in the compressor is also filled with refrigerant liquid, and liquid shock occurs when the unit is started next time.

The measures to prevent liquid shock are made completely on the basis of the causing reason of the liquid shock, including the operation guidance of the Danfoss condensing unit installation procedure, the early-stage selection of the system, and on-site debugging and matching, and various measures to prevent the migration of refrigerants.

Danfoss condensing unit compressors for cold storage are 2~15Hp, using flexible sealing technology.

The orbiting scroll is fixed flexibly, and the force generated by centrifugal force and the gas pressure difference is used to maintain the seal.

When liquid compression occurs, the scroll can be detached and the liquid is bypassed and discharged without causing hard damage to the Danfoss compressor and preventing a certain degree of liquid shock.

The Main Factors Affecting the Oil Return of Danfoss Condensing Unit Compressor and Solutions

During the running of the Danfoss condensing unit system, the refrigerant is discharged from the compressor along with the lubricating oil, after the cycling, they return to the compressor.

Then there will be lubricating oil entering and leaving the place where the refrigerant enters and exits.

The performance of refrigerant and lubricating oil is essentially different.

There are two types of refrigerant recycling in the system, namely liquid refrigerant and gas refrigerant.

Lubricating oil is basically in a liquid state.

When the refrigerant changes from liquid to gas, the lubricating oil will separate out of the refrigerant.

Under the influence of many factors, they are likely to be stored in a certain part of a certain structural point, which will cause the lubricating oil that can’t be returned to the Danfoss condensing unit compressor to smoothly, and this will cause the Danfoss condensing unit scroll compressor lack oil.

If the lack of oil cannot be resolved for a long time, It will lead to insufficient lubrication of the moving parts of the compressor, dry burning, and other failures, which greatly accelerate the damage of the Danfoss condensing unit scroll compressor.

Solutions for Poor Oil Return of Danfoss Compressors

Danfoss Condensing Unit  Installation

A. Ensure proper oil volume.

When the Danfoss condensing unit compressor discharges refrigerant, it will also discharge a trace amount of refrigerating machine oil.

Even if the oil rate is only 0.5%, if the oil cannot be circulated back to the Danfoss condensing unit compressor through the system if taking 5HP as an example, the circulation volume is about 330kg/h under ARI conditions, and the Danfoss condensing unit compressor refrigerant oil can be removed in 50 minutes.

After all the oil is taken out, the Danfoss condensing unit compressor will burn out in about 2 to 5 hours. Therefore, in order to ensure that the Danfoss condensing unit compressor is not running short of oil, the following two aspects should be started:

Ensure that the refrigerating oil discharged from the Danfoss condensing unit compressor returns to the Danfoss condensing unit compressor.

Reduce the oil rate of the Danfoss condensing unit compressor.

B. The necessary conditions to ensure that the lubricant oil discharged from the compressor returns to the compressor.

The flow rate of the refrigerant in the suction pipe (about 6m/s) should be ensured to allow the oil to return to the Danfoss condensing unit compressor, but the maximum flow rate should be less than 15m/s to reduce pressure drop and low noise. There should be a downward slope along the direction of refrigerant flow, about 0.8cm/m.

Prevent refrigerating machine oil from staying in the evaporator.

Choose the proper oil return hole of the accumulator. If it is too large, it will cause wet compression, and if it is too small, it will cause insufficient oil return and cause lubricating oil to stay in the accumulator.

Reduce the location of lubricating oil in the refrigeration system.

C. Reduce the oil rate of the Danfoss condensing unit compressor.

Make sure that the refrigerant does not dissolve into the lubricating oil during shutdown (use crankshaft heater).

Avoid over-humid operation because the over-humid operation will cause bubbles to increase so that the lubricating oil is easily taken out of the Danfoss condensing unit compressor.

An oil separator device is installed inside.

Set the necessary return bend.

Ensure proper refrigeration oil viscosity.

Danfoss Condensing Unit Equipment

A. Selection of lubricants.

Lubricating oil in Danfoss condensing unit scroll compressors mainly plays the role of lubrication, sealing, cleaning, heat dissipation, and rust prevention.

Choosing a good lubricating oil will not only improve the reliability of the Danfoss condensing unit compressor but also greatly improve the performance of the air conditioning system.

There are many criteria for the selection of lubricating oil. From the perspective of oil return, lubricating oil is required to have good flow characteristics at low temperatures.

Therefore, it is necessary to choose a low pour point to avoid adhesion at low temperatures and fail to return to the Danfoss condensing unit compressor.

B. The oil separator is generally installed on the exhaust pipe to achieve gas and oil separation through rapid pressure drop, and then return to the oil reservoir of the compressor through the oil return capillary. Currently, there are three widely used oil separators:

The oil separator with a float ball, which is widely used for refrigeration systems.

If oil accumulates in the refrigeration oil separator, the float valve set inside will open to allow the oil to return to the compressor;

Miracle supply floats ball-type oil separators for you.

Manually return the oil to the oil separator of the compressor.

If the oil collects in the oil separator, you need to manually open the oil return valve to return the oil to the compressor;

The type of oil separator doesn’t have a float valve inside.

Although this oil separator has a simple structure, it has very strict requirements on the size of the oil return piping.

C.Danfoss condensing unit system control.

System control mainly involves oil return control and oil equalization control.

In the multi-line system, under the condition of the partial load operation, the Danfoss condensing unit oil will be collected in the unoperated load.

The more unoperated load and the longer the running time, the more Danfoss condensing unit oil is collected outside the compressor, and the lubricating oil that will return to the inside of the compressor is less.

When the system runs to a certain controlled index (the index can be oil level, running time, temperature, etc.), the Danfoss condensing unit oil return system works by adjusting the whole machine load, refrigerant flow, working frequency, motor, the system air volume, and other controllable factors.

Adjust the flow rate and pressure of the refrigerant in the system by adjusting controllable factors such as the overall load, refrigerant flow, operating frequency, motor, system air volume, etc., to increase the refrigerant flow rate in the compressor and drive the return of lubricating oil.

When the monitoring system detects that the oil volume is sufficient for the compressor to operate, it enters normal load work, and so on.

The Danfoss condensing unit oil equalization occurs in the multi-line group. Similarly, detection points can be designed in the system, such as an oil level balancer, etc.

When the system detects that a compressor is lacking in lubricating oil, it can balance part of the lubricating oil from the compressor system with more lubrication to the compressor system with less lubrication through the oil equalization system.

If the second compressor is also lacking in lubricating oil, start the oil equalization again through the detection, and so on, until the oil volume of all compressor systems is balanced.

Optimized structural design is also conducive to Danfoss condensing unit oil return.

At present, the Danfoss condensing unit gas-oil balance technology is commonly used. In theory, the Danfoss condensing unit oil pressure and air pressure in the crankcase of each parallel compressor can be guaranteed, but it is not ideal in practice.

Due to factors such as the design and processing of the balance pipe, the installation of the unit, and the Danfoss condensing unit pump oil volume of each compressor, the oil pressure and air pressure of the crankcase of each compressor will be different.

Therefore, the Danfoss condensing unit oil return method must be based on the above In terms of control, don’t use more than three compressors in the refrigeration system.

Another Danfoss condensing unit oil return structure uses non-balanced technology, Danfoss’ patented structure.

The pressure in the system flow path decreases sequentially so that a pressure gradient is established in the Danfoss condensing unit compressor.

The lubricating oil first flows into the upstream compressor.

When the Danfoss condensing unit oil level is higher than the bottom of the connecting pipe, it will overflow under the action of airflow and pressure difference.

If the oil volume is normal, each compressor can get enough lubricating oil.

D.The influence of system speed and pressure on Danfoss condensing unit oil return.
The change of system operating conditions has a great influence on the flow rate, pressure, and phase of the refrigerant inside the Danfoss condensing unit scroll compressor system.

When the Danfoss condensing unit system is running, the refrigerant and lubricating oil are almost mutually soluble.

The higher the flow rate, the higher the pressure of the refrigerant in the pipeline, the more favorable it is for the return of lubricating oil. Danfoss condensing unit oil return control generally changes the refrigerant flow rate in the unit by controlling the frequency of the unit.

When the frequency of the unit increases, the greater the refrigerant flow through the Danfoss condensing unit compressor per unit time, the flowing speed and density of the refrigerant are higher in the pipeline, which will cause the increase of the lubricating oil returning speed naturally increase.

During the installation process of the multi-line unit, based on the structural requirements, the internal and external connecting pipes may exceed the conventional size. As the connecting pipes are lengthened, the system pressure loss will increase, and the refrigerant flow rate will also slow down in the system.

Oil return is extremely unfavorable. Lubricating oil will be precipitated in the slow-flowing refrigerant and attached to the inner wall of the pipeline, which will cause the lubricating oil to accumulate in some parts that are easy to store oil so that the lubricating oil cannot completely return to the compressor.

So you need to :

Choose lubricating oil with low pour point as much as possible, which is conducive to the flow of lubricating oil in the pipeline;

Choose the suitable oil separator and accumulator, and the influence of the length of the connecting pipe on the oil return cannot be ignored.

When the connecting pipe is too long, corresponding treatment should be done, such as increasing lubrication;

Consider oil return factors as much as possible in the initial stage of design, and optimize system oil return through structural design;

Frequency plays a vital role in the flow and velocity of the refrigerant. As the frequency increases, the flow and velocity will increase, and the oil return will also increase.

Are You the Manufacturer of the Danfoss Condensing Unit?

Yes, we manufacture the Danfoss condensing unit for more than 20 years, and our Danfoss condensing unit is popular in the domestic market and overseas market.

For Danfoss condensing unit, we have several types of appearance for the box, you can choose A type or B type side blowing for the box, and you can also choose A type top blowing for the box according to your project site situation.

Can You Provide the Refrigeration Parts of the Danfoss Condensing Unit Separately?

Yes, we are not only providing the whole complete Danfoss condensing unit, any parts you need of it, but we can also supply it separately.

Can You Do OEM for Danfoss Condensing Unit and Refrigeration Parts for Us?

Yes, if we do have life-long cooperation, we can do OEM for all of the parts of the Danfoss condensing unit, including the labels, packages, and so on.

Can You Provide a Danfoss Compressor Only?

Yes, we have close cooperation with Danfoss compressor agents, so we can get the original Danfoss compressor at good prices, if you need it, we would like to help.

How is the Package and Delivery for Danfoss Condensing Unit?

Normally we use fumigated wood or wood case that can be exported, sometimes for the small condensing unit, we use a carton box, we will show you what kind of package we use when you order the Danfoss condensing unit.

For the delivery, we cooperate with an experienced forwarder, which can provide us good shipping line, good cost no matter you want to ship the goods by sea, by air, or by train, always provide the best solution.

How Long Time for the Production Time of the Danfoss Condensing Unit?

It depends on your order. Normally if you are choosing the standard Danfoss condensing unit, it will be very quick,15-20days, because we have a Danfoss compressor for stock. If it’s the special model and special demand, it will be longer, we will try our best to short of the time, check that with us with firmed order.

Do You Have a Guarantee for the Danfoss Condensing Unit?

Yes, for the Danfoss compressor and main parts of the Danfoss condensing unit, we have a 1-year guarantee. You can check with us with firmed order, we provide an accurate guarantee time for you.

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