Technical specifications and initial technical data

Technical specifications

Technical specifications shall contain the following sections:

  • name, purpose and application field;
  • design purpose;
  • basis for designing;
  • design function;
  • technical requirements for product;
  • technical-and-economic indexes;
  • stages and phases of designing;
  • check and acceptance procedure;
  • annexes.

Depending on the product peculiarities it is allowed to specify the sections contents, to add new sections or combine some of them.

In addition, TS may be completed with the following items but not limited to:

  • Intended use requirements.
  • Viability and environmental durability requirements.
  • Construction requirements.
  • Reliability requirements.
  • Ergonomics, habitability and technical aesthetics requirements.
  • Safety and environmental protection requirements.
  • Standardization and unification requirements.
  • Technological effectiveness requirements.
  • Transportability requirements.
  • Patent clearance requirements.
  • Technical-and-economic requirements.
  • Support types requirements.
  • Metrological support requirements.
  • Control system requirements.
  • Requirements to raw stock, materials and component parts of inter-branch application.
  • Operation, storage, maintainability and repair requirements.
  • Preservation, packing and marking requirements.

Initial technical data

Also the initial technical data, more simplified document, can be accepted by the Parties as a basis for works instead of technical specifications.

The documents, which can be downloaded by this link, can be used as initial technical data.

Let us consider the example of drawing up the initial technical data for designing of chillers with condenser water cooling.

In the initial technical data the equipment technical characteristics are agreed between the Designer (who can also be the Manufacturer at the same time) and the Customer – equipment parameters received at inlet and outlet – the type of cooling medium (of cooled product liquid), its temperature, flow characteristics, consumed electric power, refrigeration capacity and others, which are necessary to ensure a technological process, heat and humidity parameters in the compartment equipped with a chiller.

The chiller system elements have not been known yet. In this case, the chiller designing will be based on standard solutions and diagrams, that’s why for technical characteristics designations the dimensional drawing (Figure 1) of the chiller with standard construction is used.

The example of drawing up the initial technical data for water-cooled refrigeration machine (chiller) for cooling a 30% solution of ethylene glycol, with water-cooled condenser having the refrigeration capacity of 250 kW, is shown in tabular form (Table 1) below.

General-view-of-refrigeration-machine-with-identifier-of-initial-parameters

Figure 1. General view of refrigeration machine with identifier of initial parameters.

Table 1. Initial technical data.

Srl. No.

Name of parameter and variant selection (if available)

Measurement units

Valur

Note

1

Type of chiller:

-

Only cooling

Only cooling
Heat pump

2

Condenser:

-

Water-cooled

Air-cooled
Water-cooled
Without condenser

3

Type of compressor:

-

Screw

Scroll
Reciprocating
Screw
Centrifugal

4

Required refrigeration capacity

kW

250

5

Required heat capacity

-

6

Cooling medium temperature at heat-exchange apparatus 1 inlet (evaporator)

°С

12±1

Cooling mode

7

Cooling medium temperature at heat-exchange apparatus 1 outlet (evaporator)

7±1

8

Heating medium temperature at heat-exchange apparatus 1 inlet (condenser)

-

Heat mode

9

Heating medium temperature at heat-exchange apparatus 1 outlet (condenser)

-

10

Cooling liquid temperature at heat-exchange apparatus 2 inlet (condenser)

from minus 2 to plus 40 ºС

Cooling mode

11

Cooling medium temperature at heat-exchange apparatus 2 inlet (evaporator)

-

Heat mode

12

Cooling/heating medium in evaporator loop

-

Ethylene glycol 30

13

Cooling/heating medium in condenser loop

-

Ethylene glycol 30

14

Operation mode:

-

Warm period of year

Year-round
Warm period of year
15 Type of refrigerant

-

R507

The example of drawing up the initial technical data for designing, calculating and selecting the refrigeration unit to cool products in the chamber is given below.

General-view-of-cooling-chamber-with-identifier-of-initial-parameters

Figure 2. General view of cooling chamber, with identifier of initial parameters.

Table 2. Initial technical data.

Parameter

Measurement unit

Value

Intended use of cooling chamber: cooling/freezing/storage

-

storage

Dimensions of cooling chamber internal space
Length, L

m

8

Width, В

5

Height, H

3

Ambient temperature, tambient

°С

32

Temperature in cooling chamber, tchamber

from -12 to -16

Temperature of loaded product

-15

Product final temperature

-16

Relative humidity, φchamber

%

80-90

Refrigeration capacity

kW

4,5

Walls insulation thickness
Wall A, Sa

mm

150

Wall B, Sb

150

Wall C, Sc

150

Wall D, Sd

150

Floor

250

Ceiling

250

Door opening size, doors quantity

mm х mm

800 x 2000

Walls insulation material

-

Foamed polystyrene 35 kg/m³

Heat conduction coefficient of insulation material

W/(m*K)

0,02

Product cooling treatment time (cooling, freezing)

h

24

Doors opening duration per day

0,25

Doors opening quantity per day

pcs

2

Loaded product quantity

kg

5000

Daily goods turnover

500

Lighting consumed power, Рlight

W

100

Storage products

-

Meat products

Type of product package

Cardboard

Ventilation in chamber

Inlet ventilation, 10 m³/h

Location of refrigeration unit in compartment/outdoors

Outdoors

Chambers quantity

pc

1

To become familiar with all design stages and examples of their performance, proceed to the review of article “Stages of designing”.

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