Heat supply system of AGZU with heat pump

Contents

1 Heat Pump Equipment Solution

2 Heat Pump Equipment Placement Solution

3 Explosion protection solutions

4 Solution for selection of equipment for automatic control of heating process of AGZU building bush No.

5 Equipment operation modes

6 Solution for equipment installation and layout of routes and external wiring

Appendix A - Certificate of Conformity

Appendix B - Custom BOM

Appendix C - List of flammable works

2 Heat Pump Equipment Placement Solution

Heat pump plant includes evaporator, heat pump and condenser.

The equipment located in the AGZU room includes:

capacitor with explosion-proof fan (K1) controlled by frequency converter;

Explosion-proof control station;

explosion-proof temperature sensor.

Equipment located outdoors (on the street) includes:

evaporator (I1);

heat pump (TN).

The project provides for:

TN to be installed outside AGZU (Diagram "Equipment Layout and External Wiring Plan"). Overall dimensions (VhShhG, oo) 1000х800х300. Install close to the AGZU wall. Attach to wall on steel structure (steel angle);

And 1 is a structure described below. A copper pipe 50 meters 10 mm long is wound close to the pipe 114x6. A layer of thermoplastic of KPT type is laid between the copper pipe and the GZHS pipe, and insulation of KFLEX type is provided on top of the copper pipe.

With insufficient evaporator power, which will be detected during commissioning, it is necessary to organize a steel jacket in the form of a 219x6 pipe, which is filled with antifreeze, to increase the surface area of ​ ​ heat exchange between the antifreeze and the GHS pipe and antifreeze and copper pipe, which will also provide an increase in inertia. Choose antifreeze for use in heating and air conditioning systems of type "DIXIS30," in order to prevent "defrosting" at low temperatures, as well as to protect equipment from corrosion, scale formation, microorganisms development. Total mounting length I1 is 2 m;

K1 to be installed inside the room under the ceiling above pipeline No. 807. Overall dimensions of the condenser (VhShhG, oo) 520х650х580;

ERP to be installed inside the AGZU to the left of the capacitor;

install temperature sensor on opposite wall relative to condenser.

3 Explosion protection solutions

An explosive zone is a space in which an explosive environment is present or may be formed in such an amount that special precautions may be required in the design, installation and operation of electrical equipment.

The object of the TN plant refers to a zone in which there is a risk of a gas explosive environment, namely associated petroleum gas. According to the conditions of formation of explosive medium, frequency of its occurrence and duration of existence, the zone of the control object belongs to explosion class B1a (according to PUE). Therefore, this is a room in which FFL vapors and explosive mixtures arise due to malfunctions and accidents, and do not form during normal operation (whatever the value of the minimum concentration for ignition).

Class B1a includes the entire territory of the bush site.

Depending on the temperature of self-ignition, explosive mixtures of gases and vapors with air are divided into groups. Associated oil gas has a different composition depending on the type. The main component of associated petroleum gas is methane, which can make up from 67 to 92% of the total volume. The lowest temperature of methane self-ignition in mixture with air at atmospheric pressure is 650 0C, other components (ethane, propane, butane, pentane), which are part of associated gas from 300 to 500 0С, the self-ignition temperature of heavy oil residues is 300350 ° С. According to PUE (Table 7.3.2) the mixture of associated gas with air belongs to group T2 of explosive mixtures of gases and vapors with air by self-ignition temperature.

In this regard, requirements are imposed on the level of explosion protection of the used equipment (GOST R 51330.099).

Electrical equipment with corresponding PUE (item 7.3.63) explosion protection levels is selected in the design. To reduce overall dimensions and ensure interchangeability, all equipment has a general industrial design and can be divided into two groups: electrical equipment (electrical appliances, machines, signal equipment, wiring, cable glands) and hydraulic part (coolant routes).

1) Selection of electrical equipment

According to the project, the following are installed in the explosive zone:

a) condenser with the 0.25 kW fan explosion-proof BO063004P and with a performance of 2000 - 3200 m3/hour.

It has an explosion protection level - increased reliability against explosion, used to service explosive rooms B1A (in accordance with the requirements of PUE, Table 7.3.10);

b) explosion-proof Cortem control post has version 1ExdIIBT5 - increased reliability against explosion (complies with PUE requirements, Table 7.3.11). The degree of protection provided by the IP66 shell;

c) explosion-proof temperature sensor ARIES of DTS 125Pt 100 series. It is marked with explosion protection 0ExiaIICT5 (meets the requirements of PUE table 7.3.11);

d) explosion-proof cabinet with heat pump (see detailed justification below)

e) cables for electrical equipment connection are selected in accordance with PUE para 7.3102 .

Power cables are selected as VBGng 4x4, which are intended for transmission and distribution of electric power in stationary installations, including in rooms and outdoors with explosion hazard class B1a.

Cables control for connection of VPU are chosen brands KVVGNG 10х0.75 which are intended for motionless accession to electric devices, devices, assemblies of clips of electric distributing devices, for laying in rooms, canals, tunnels, in the conditions of hostile environment, in the absence of mechanical impacts on a cable.

Control universal cables for connection of the temperature sensor are selected as MKASH 3x0.75, which are intended for stationary laying inside and outside the room, in an explosive area.

To protect electrical circuits located in the safe area (controller) from dangerous signal levels from devices located in the explosive area, the ISKRATS.01 intrinsic safety barrier of the ARIES manufacturer is installed in the TN cabinet, which limits the value of voltage and current to intrinsically safe ones. It is used according to the marking of explosion protection, GOST R 51330.1399, chap. 7.3 of PUE and other regulatory documents.

Cable entry into electrical machines, devices, during transition to explosion-proof zone or through fences, shall be performed in accordance with PUE (items 7.3.112 - 7.3.114). Unarmored cables in accordance with PUE item 7.3.121 shall be laid in metal or steel non-perforated conduit.

TN has street performance. The area of its location belongs to the class of explosion and fire hazard B1a. TN contains general industrial equipment that does not have explosion protection facilities. To fulfill the requirements of PUE on switchgears and boards, the explosion-proof housing of the KEL series of the manufacturer Rittal is selected. The cabinet corresponds to the explosion and fire hazard zone of class B1a (according to the PUE classification), has a certificate of compliance No. ROSS DE.ML14.B00232 (Appendix A), meets the requirements of regulatory documents GOST R 51330.099, GOST R 51330.899 (Explosion-proof electrical equipment. Protection type e) for control boards and switchgears located in the area of class B1a.

The KEL housing is designed for use in hazardous areas. The enclosure complies with the "e" ignition prevention requirements for Group II explosion-proof equipment.

Explosion protection class II 2 G EEx e II

Equipment marking PTB 03 ATEX 1013U

Cabinet 9408.600 (ShxVxG, mm 800x1000x300) is made of stainless steel, has the degree of protection IP 66 and is suitable for outdoor installation.

The explosion-proof CORTEM cable entry of the FG series for unarmored cable and the explosion-proof CORTEM cable entry of the FGF series for unarmored cable in metal cabinets are selected for cable entry into the TN cabinet, inside of which the explosion-proof medium are selected.

2) Organization of hydraulic part of the system

It is assumed that the R407C refrigerant is constantly circulating in the heat supply circuit. Refrigerants (freons), are gases or liquids under normal conditions, are non-toxic, do not form explosive mixtures with air, do not react with most metals. Ozone depletion potential for R407C is zero, MPC has not been established. Hazard class 4 (low). When in contact with the flame and hot surfaces, it decomposes to form highly toxic products.

According to GOST R 12.2.14299 "Refrigeration systems with a refrigerating capacity of more than 3.0 kW," restrictions on the use of electrical equipment are imposed if the refrigerant belongs to group 2 and 3. Group 1 refrigerants and Group 2 non-flammable refrigerants need no other special precautions.

In accordance with PUE:

in the walls of RP, TP, PP and shields, to which explosive zones with light combustible gases and VFL adjoin, including class B1a, it is allowed to arrange holes for the introduction of cables and wiring pipes into RP, TP and PP, the inlet holes must be tightly sealed with non-combustible materials. RP, TP, PP and boards exits shall be performed in accordance with SNiP 210197 "Fire safety of buildings and structures";

it is forbidden to lay pipelines with fire and explosive, as well as with harmful and caustic substances through shields and panels.

In this case, when laying a copper pipe with non-flammable refrigerants, the holes for entering the TN board will be hermetically made using an explosion-proof cable entry.

Compliance with explosion safety measures in the event of a spark in the safe zone of the TN will not allow the flame to spread into the explosive zone.