Danfoss Cold Room Calculation and Component Selection in Coolselector 2 User guide

Cold Room Calculation

and Component Selection

in Coolselector®2

Calculation of Heat Load and Selection of

System Components

Danfoss A/S

2017-07-25

Version 1.10

Calculation of cold room capacity, calculation and selection of all required system components in one go within Coolselector®2.

Cold Room Calculation and Component Selection in Coolselector®2

Contents


Introduction ....................................................................................................................................			3
Manual Calculation .........................................................................................................................			4
Wizard for Guided Input and Value Estimation ..............................................................................			5
3.1	Dimensions and Surroundings ................................................................................................		6
3.2	Goods ......................................................................................................................................		6
3.2.1 Estimate the Mass of Goods ...............................................................................................			7
3.2.2		Storage Conditions..............................................................................................................	8
3.3	Insulation Panels .....................................................................................................................		9
Humid Air: Consequences and Influence on Heat Load .................................................................			9
Additional Loads..............................................................................................................................			9
5.1	Light.........................................................................................................................................		9
5.2	Fan Power .............................................................................................................................		10
5.3	Defrost Heater ......................................................................................................................		10
Condensing Unit............................................................................................................................			11
System Conditions.........................................................................................................................			11
7.1	Determining the Evaporation Temperature .........................................................................		12
7.2	Calculate Optimal Superheat at Evaporator Outlet..............................................................		13
7.3	Determining the Cooling Time Per Day.................................................................................		13
Component Calculation and Selection..........................................................................................			15
8.1	Evaporator.............................................................................................................................		15
8.2	Pipes......................................................................................................................................		15
8.2.1		Suction Line.......................................................................................................................	15
8.2.2		Liquid Line .........................................................................................................................	15
Tips & Tricks ..................................................................................................................................			16
9.1	Walls & Insulation .................................................................................................................		16
9.2	Edit Selection ........................................................................................................................		17
9.2.1 Re-Start Cold Room Calculation........................................................................................			17
9.2.2		Manual Editing..................................................................................................................	17
9.2.3 Utilizing the “Copy” Function............................................................................................			18
	Closing Remarks........................................................................................................................		18

Cold Room Calculation and Component Selection in Coolselector®2

Introduction

To prolong lifetime and usability of perishable goods like food, milk, medicals and other temperature sensitive items, cold rooms or so called “walk-in rooms” are used.

Since all goods have their individual storage requirements in terms of temperature and humidity, the challenge is to design the cold room refrigeration system in a way that exactly matches the required conditions.

Cooling capacity is equal to the heat load of the cold room, which is given by the heat transition through the walls, the incoming goods, the respiration of goods, the evaporator fan(s), the air change, the human activities (e.g. walking in and out) as well as several other factors.

The Cooolselector®2 cold room application calculation provides an easy way for users to obtain professional results. This, the first version, is made for single cold rooms and one- to-one system setups.

When starting up a cold room calculation within Coolselector®2, the software will launch a wizard to define a cold room load (it is also possible to define this manually).

Figure 1.1 Cold room load calculation wizard

In this guide, you will get further information about the Coolselector®2 cold room application.

Cold Room Calculation and Component Selection in Coolselector®2

Manual Calculation

When starting up a cold room calculation within Coolselector®2, apart from using a wizard to define the cold room load, it is also possible to manually input the needed values.

Simply choose the option ‘Manually Define Cold Room Load’ and you will be guided to a new screen where you can input all necessary values (see fig 2.2).

Figure 2.1 Manual definition of cold room load

Important: Please note that the manual input option is meant as a tool for users who has in-depth knowledge of all the different values required to calculate the heat load of a cold room.

Cold Room Calculation and Component Selection in Coolselector®2

When the manual method is used it is important that you ensure you check and change all values yourself. Only a few automatic calculations will happen within Coolselector®2, these being air-exchange rate and temperature difference, evaporation temperature and useful superheat.

Figure 2.2 Manually reviewing the cold room load

Wizard for Guided Input and Value Estimation

The wizard supports calculation or estimation of important values, which influence not only the heat load calculation, but also the storage and refrigeration system conditions. This is important to ensure the quality of the stored goods.

Figure 3.1 Wizard for defining the cold room load

Important: The suggested values are based on application know-how. Individual solutions may require different values. Therefore, all values can be overwritten by users.

Cold Room Calculation and Component Selection in Coolselector®2

3.1 Dimensions and Surroundings

This part of the wizard asks you to input either the inner or the outer dimensions of the cold room you wish to calculate on as well as details about the room surroundings.

Room surroundings such as temperature and humidity is used for the calculation of heat transfer through the walls. Opening and closing the door to the cold room influences the heat load due to the air-exchange with humid air from the outside.

Figure 3.2 Dimensions and surroundings

3.2 Goods

The type of stored goods can be selected from the drop-down list. Furthermore, there is the option to give detailed information about quantity and inlet temperature. On the basis of this input a separate wizard can be used to estimate the mass from the room volume (please see 3.2.1 for further information).

Figure 3.3 Goods

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