The process of adiabatic cooling

CONTENTS

1 Introduction.................................................................................................. 1

1.1 General overview........................................................................................... 1

1.2 Aims............................................................................................................... 2

1.3 Methods......................................................................................................... 2

2 Adiabatic cooling....................................................................................... 4

2.1 Adiabatic cooling........................................................................................... 4

2.2 The process of adiabatic cooling.................................................................... 5

2.3 Indirect adiabatic cooling............................................................................... 6

2.4 Heat exchangers in traditional indirect adiabatic cooling.............................. 8

3 SYSTEMS BASED ON MAISOTSENKO CYCLE........................................... 11

3.1 Maisotsenko exergy tower........................................................................... 11

3.2 Maisotsenko combustion turbine cycle........................................................ 12

3.3 Other systems............................................................................................... 15

4 COOLERADO COOLERS.................................................................................. 17

4.1 Operation principle....................................................................................... 17

4.2 Coolerado coolers......................................................................................... 19

4.3 Comparison with traditional adiabatic and compressor cooling systems..... 21

4.4 Products....................................................................................................... 23

4.4.1 Pre-cooling systems.......................................................................... 23

4.4.2 Stand alone systems......................................................................... 24

4.4.3 Hybrid systems................................................................................. 25

5 APPLICABILITY IN NORTHERN CLIMATE................................................. 27

5.1 Initial data.................................................................................................... 27

5.2 Method of calculation.................................................................................. 27

5.3 Results and analysis..................................................................................... 28

6 CONCLUSIONS.................................................................................................. 32

BIBLIOGRAPHY 34

Introduction

General overview

Nowadays, great attention is paid to the environment, energy saving and energy efficiency. Energy production often adversely affects the environment and increases greenhouse gas emissions. Despite this, the global energy consumption grows from year to year. That is why the question of the development of new, cleaner and more efficient technologies was acutely raised in recent years.

A large part of the world's energy is consumed by ventilation and air-conditioning. Practically in each modern building ventilation and air-conditioning systems are installed. Even many of the old buildings where possible, are equipped with modern ventilation systems. Many of building facilities, such as hospitals and industrial buildings, have specific requirements for ventilation and air conditioning systems.

One of the most energy-intensive processes in the ventilation and air-conditioning is the process of air cooling. Traditional systems based on the compressor cycle consume a lot of energy. Refrigerants contained in compressor circuits are often very harmful to the environment.

These factors led to the active development of evaporative coolers. Air coolers based on evaporative cooling of the air consume far less energy compared to traditional compressor systems. They are also ecological and environmental-friendly systems.

However, the efficiency of evaporative air cooling systems is strongly dependent on the state of the air. The most suitable conditions for these systems are the areas with a hot and dry climate. Determining factor in this case is the air wet bulb temperature. This is the theoretical maximum temperature to which air can be cooled.

However, this was not the limit, and the former soviet scientist Valery Maisotsenko improved evaporative cooling technology and called the resulting cycle as Maisotsenko-cycle (=M-cycle). He also patented a series of devices based on the M-cycle. The application of this cycle improves the efficiency of the existing devices, and allows create new devices with better performance than their analogues.

Some of the devices based on the M-cycle are Coolerado air conditioners. These air conditioners have very low power consumption and the ability to cool the air below the wet bulb temperature. The determining factor for these conditioners is the dew point temperature - theoretically the lowest temperature to which air can be cooled using this technology.

Coolerado air conditioners are increasingly used throughout the world. Due to a greater range of cooling, these systems can be used in many parts of the world. And due to the low power consumption, they can greatly reduce the energy consumption for ventilation and air conditioning.

Aims

This work has following aims. The first aim is to get acquainted and understand principles of the M-cycle. This is an innovative and versatile technology that can improve the effectiveness of many technological areas.

The second aim is to review the systems from different areas based on the M-cycle. Perhaps in the near future the use of these systems may change a lot in many fields.

The next aim is to figure out the advantages of the Coolerado air-conditioners compared to traditional evaporation and compressor systems.

The final aim is to calculate the possibility of using Coolerado air conditioners in Scandinavian climate, for instance in Finland.

Methods

In order to reach specified aims the following methods are applied. The first method is the literature review. There is not much information about topic of this thesis, because it is a pretty new and innovative system. The first area in which this invention was applied is ventilation and air conditioning. Since the equipment based on the new technology was successful, the active implementation of this technology is going in other fields. So the main literature resources for this thesis work are patents of these systems, magazine articles and information given by the manufacturer.

The second method is analysis of differences between traditional adiabatic cooling systems and evaporative systems based on M-cycle. The main advantages and disadvantages of these systems will be figured out.

The next method is the comparison. The main points and differences will be compared. Advantages and disadvantages of one system relative to another will be showed.

The last method is calculation of the possible use of this system in Scandinavian climate. Data obtained during the independent testing of these systems will be used to assess their performance. By using climatic data for Finland and tested data of the performance of these systems, conclusion about the applicability of these systems in the Scandinavian climate will be drawn.

Adiabatic cooling

Maisotsenko cycle (=M-cycle) is a particular case of indirect adiabatic (evaporative) cooling (=IAC) in air conditioning systems. Interest in using the technology of adiabatic cooling in air conditioning systems is caused by a number of advantages, the most important of which is a radical reduction of energy consumption. Systems based on the M-cycle allow achieving of even greater efficiency of adiabatic cooling.

Adiabatic cooling

For the first time the method for indirect adiabatic cooling was patented by Valery S. Maisotsenko and Alexandr N. Gershuni in 1987 in USSR. After that they patented it in the United States of America in 1990 as “Method for indirect-evaporative air cooling”. “The present invention relates to methods for air cooling with the use of heat-exchangers of the indirect evaporative type and can find most utility when applied for air cooling in those premises or accommodations which must be isolate from the surrounding atmosphere either for technological reasons or on account of labor protection condition, etc.”. /1, p.3./

The traditional source of cold in air conditioning systems is a thermodynamic process in refrigerating circuit. In systems with adiabatic cooling technology, the source of cold is an adiabatic process - a special case of the thermodynamic process. This approach allows you to completely or partially abandon compressor in cooling, which is the main consumer of electricity.

In the recent past adiabatic cooling systems were primarily used in areas with dry and hot climate. But the latest development of HVAC equipment manufacturers has demonstrated great potential for the use of adiabatic cooling systems in European temperature regions. Determining factor in the use of adiabatic cooling systems is the outdoor wet bulb temperature in the summer time. /2./

Adiabatic cooling process occurs as a result of contact between the evaporating water particles with air flow. Potential cooling effect can be estimated from the difference between the outdoor temperature and its wet bulb temperature. The greater this temperature difference, the greater the potential effect of cooling.

The process is called adiabatic, because it goes without heat exchange with the environment. Cooling is achieved by the fact that the particles of water take heat from the air during the evaporation process.

The process of adiabatic cooling

When the water evaporates into the air, it takes heat from the air. This heat is usually called latent heat. It consists of two parts. The first part is the heat, which is needed to vaporize water from liquid to vapour (phase transition from liquid phase to gas phase). The second part is the heat, which is needed to superheat water vapour to the air temperature.

The main idea of the adiabatic cooling is shown in the Mollier chart in the Figure 1.

Date: 2015-12-11; view: 1436