Method and computer program product for evacuation of contaminated air and prevention of ignition in an air handling system

Abstract

A safety system (1) for evacuation of contaminated air and prevention of ignition in an air handling system (2). The air handling system (2) comprises a supply air unit (3) arranged in a supply air duct (4), and an exhaust air unit (5) arranged in an exhaust air duct (6). The safety system (1) further comprises a supply air contamination sensor (7) arranged in the supply air duct (4), an exhaust air contamination sensor (8) arranged in the exhaust air duct (6). The supply air contamination sensor (7) and the exhaust air contamination sensor (8) collect air contamination data (9). The air handling system (2) further comprises a control unit (10) for comparison of collected air contamination data (9) to a predefined air contamination data threshold value (11), and for controlling the supply air unit (3), and the exhaust air unit (5).

Claims

1. A method for controlling a safety system for evacuation of contaminated air and prevention of ignition in an air handling system, wherein the air handling system comprises a compressor for compressing a refrigerant for further being led through an evaporator/condenser coil arranged in the air handling system, a supply air unit arranged in a supply air duct, and an exhaust air unit arranged in an exhaust air duct, wherein the safety system comprises a supply air contamination sensor arranged in the supply air duct, an exhaust air contamination sensor arranged in the exhaust air duct, wherein the supply air contamination sensor and the exhaust air contamination sensor collect air contamination data, wherein the air handling system further comprises a control unit for comparison of collected air contamination data to a predefined air contamination data threshold value, and for controlling the supply air unit, and the exhaust air unit, wherein the air handling system further comprises a power supply for providing power to the supply air unit, the exhaust air unit and the control unit, and wherein a supply air valve, variable between a closed and an open position, arranged in a supply air outlet end of the supply air duct for the supply of supply air (As) to a room, an extract air valve, variable between a closed and an open position, arranged in an extract air inlet end of the exhaust air duct for the extraction of used extract air (AE) from the room into the exhaust air duct, and a by-pass valve, variable between a closed and an open position, arranged to connect the supply air duct and the exhaust air duct for the fluid connection of supply air (As) in the event that the supply air valve and the extract air valve are closed, wherein the supply air valve, the extract air valve and the by-pass valve are controlled by the control unit, wherein the method comprises the steps of: a) continuously retrieving air contamination data by means of the air contamination sensors, b) comparing the retrieved air contamination data to the predefined air contamination data threshold value by means of the control unit, when a value (v1) of a first contaminant in the retrieved air contamination data is higher than the predefined air contamination data threshold value, the control unit sends instructions to: c) start the supply air unit and the exhaust air unit, when said units are not operating, d) opening the by-pass valve, closing the supply air valve, and closing the extract air valve, wherein step d occurs prior to step e; e) stop the compressor, when said compressor is operating, f) increase the speed of the supply air unit and the exhaust air unit to a predefined maximum speed, when said units are operating at a current speed lower than a predefined speed, and when a value (v2) of the first contaminant in the retrieved air contamination data is lower than the predefined air contamination data threshold value, the control unit sends instructions to: g) stop the supply air unit and the exhaust air unit after a predefined time.

2. Method according to claim 1, wherein the safety system further comprises an outdoor air valve, variable between a closed and an open position, arranged in an outdoor air inlet end of the supply air duct for the supply of supply air (As) into the supply air duct, an exhaust air valve, variable between a closed and an open position, arranged in an exhaust air outlet end of the exhaust air duct for the exhaust of used extract air (AE) from the exhaust air duct to the ambient, and wherein the outdoor air valve and the exhaust air valve are controlled by the control unit, wherein the method further comprises, before step c, the steps of: a) opening the outdoor air valve, and, b) opening the exhaust air valve.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The invention is now described, by way of example, with reference to the accompanying drawings, in which:

(2) FIGS. 1, 3, 4, 5 and 6a show a safety system for evacuation of contaminated air and prevention of ignition in an air handling system, in a front view, according to an embodiment of the invention, and

(3) FIGS. 2, 6b and 6c shows a safety system for evacuation of contaminated air and prevention of ignition in an air handling system, from above, according to an embodiment of the invention, and

(4) FIG. 7 shows a flow chart of a method according to an embodiment of the invention, and

(5) FIG. 8 shows a flow chart of a method according to an embodiment of the invention, and

(6) FIG. 9 shows a flow chart of a method according to an embodiment of the invention, and

(7) FIG. 10 shows a block diagram of a control system according to an embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

(8) In the following, a detailed description of a safety system for evacuation of contaminated air and prevention of ignition in an air handling system is provided.

(9) FIG. 1 shows a safety system 1 for evacuation of contaminated air and prevention of ignition in an air handling system 2, according to an embodiment of the invention. The air handling system 2 is made up of a compressor 36 for compressing a refrigerant 37 for further being led through an evaporator/condenser coil 38 arranged in the air handling system 2, a supply air unit 3 arranged in a supply air duct 4, and an exhaust air unit 5 arranged in an exhaust air duct 6. The safety system 1 is made up of a supply air contamination sensor 7 arranged in the supply air duct 4, an exhaust air contamination sensor 8 arranged in the exhaust air duct. The supply air contamination sensor 7 and the exhaust air contamination sensor 8 collect air contamination data. The air handling system 2 is further made up of a control unit 10 for comparison of collected air contamination data 9 to a predefined air contamination data threshold value 11, and for controlling the supply air unit 3, and the exhaust air unit 5. The air handling system 2 is further made up of a power supply 12 for providing power to the supply air unit 3, the exhaust air unit 5 and the control unit 10. The compressor 36 is arranged within the exhaust air duct 6.

(10) FIG. 2 shows a safety system 1 for evacuation of contaminated air and prevention of ignition in an air handling system 2, according to an embodiment of the invention. The compressor 36 is arranged within the exhaust air duct 6. The system is further made up of an extract air valve 15, variable between a closed and an open position, arranged in an extract air inlet end 16 of the exhaust air duct 6 for the extraction of used extract air A.sub.E from the room 35 into the exhaust air duct 6. The system is further made up of an exhaust air valve 20, variable between a closed and an open position, arranged in an exhaust air outlet end 21 of the exhaust air duct 6 for the exhaust of used extract air A.sub.E from the exhaust air duct 6 to the ambient. The extract air valve 15 and the exhaust air valve 20 are controlled by the control unit 10.

(11) FIG. 3 shows a safety system 1 for evacuation of contaminated air and prevention of ignition in an air handling system 2, according to an embodiment of the invention. The air handling system 2 is made up of a compressor 36 for compressing a refrigerant 37 for further being led through an evaporator/condenser coil 38 arranged in the air handling system 2, a supply air unit 3 arranged in a supply air duct 4, and an exhaust air unit 5 arranged in an exhaust air duct 6. The safety system 1 is made up of a supply air contamination sensor 7 arranged in the supply air duct 4, an exhaust air contamination sensor 8 arranged in the exhaust air duct. The supply air contamination sensor 7 and the exhaust air contamination sensor 8 collect air contamination data. The air handling system 2 is further made up of a control unit 10 for comparison of collected air contamination data 9 to a predefined air contamination data threshold value 11, and for controlling the supply air unit 3, and the exhaust air unit 5. The air handling system 2 is further made up of a power supply 12 for providing power to the supply air unit 3, the exhaust air unit 5 and the control unit 10. The compressor 36 is arranged within a compressor enclosure 22 (not shown) separate from the supply air duct 4 and the exhaust air duct 6. A compressor enclosure contamination sensor 23 is arranged in the compressor enclosure 22 for collection of air contamination data 9.

(12) FIG. 4 shows a safety system 1 for evacuation of contaminated air and prevention of ignition in an air handling system 2, according to an embodiment of the invention.

(13) The air handling system 2 is made up of a compressor 36 for compressing a refrigerant 37 for further being led through an evaporator/condenser coil 38 arranged in the air handling system 2, a supply air unit 3 arranged in a supply air duct 4, and an exhaust air unit 5 arranged in an exhaust air duct 6. The safety system 1 is made up of a supply air contamination sensor 7 arranged in the supply air duct 4, an exhaust air contamination sensor 8 arranged in the exhaust air duct. The supply air contamination sensor 7 and the exhaust air contamination sensor 8 collect air contamination data. The air handling system 2 is further made up of a control unit 10 for comparison of collected air contamination data 9 to a predefined air contamination data threshold value 11, and for controlling the supply air unit 3, and the exhaust air unit 5. The air handling system 2 is further made up of a power supply 12 for providing power to the supply air unit 3, the exhaust air unit 5 and the control unit 10. The safety system 1 is further made up of a supply air valve 13, variable between a closed and an open position, arranged in a supply air outlet end 14 of the supply air duct 4 for the supply of supply air A.sub.S to a room 35, an extract air valve 15, variable between a closed and an open position, arranged in an extract air inlet end 16 of the exhaust air duct 6 for the extraction of used extract air A.sub.E from the room 35 into the exhaust air duct 6, and a by-pass valve 17, variable between a closed and an open position, arranged to connect the supply air duct 4 and the exhaust air duct 6 for the fluid connection of supply air A.sub.S in the event that the supply air valve 13 and the extract air valve 15 are closed. The supply air valve 13, the extract air valve 15 and the by-pass valve 17 are controlled by the control unit 10. The compressor 36 is arranged within a compressor enclosure 22 (not shown) separate from the supply air duct 4 and the exhaust air duct 6. A compressor enclosure contamination sensor 23 is arranged in the compressor enclosure 22 for collection of air contamination data 9.

(14) FIG. 5 shows a safety system 1 for evacuation of contaminated air and prevention of ignition in an air handling system 2, according to an embodiment of the invention. The air handling system 2 is made up of a compressor 36 for compressing a refrigerant 37 for further being led through an evaporator/condenser coil 38 arranged in the air handling system 2, a supply air unit 3 arranged in a supply air duct 4, and an exhaust air unit 5 arranged in an exhaust air duct 6. The safety system 1 is made up of a supply air contamination sensor 7 arranged in the supply air duct 4, an exhaust air contamination sensor 8 arranged in the exhaust air duct. The supply air contamination sensor 7 and the exhaust air contamination sensor 8 collect air contamination data. The air handling system 2 is further made up of a control unit 10 for comparison of collected air contamination data 9 to a predefined air contamination data threshold value 11, and for controlling the supply air unit 3, and the exhaust air unit 5. The air handling system 2 is further made up of a power supply 12 for providing power to the supply air unit 3, the exhaust air unit 5 and the control unit 10. The safety system 1 is further made up of a supply air valve 13, variable between a closed and an open position, arranged in a supply air outlet end 14 of the supply air duct 4 for the supply of supply air A.sub.S to a room 35, an extract air valve 15, variable between a closed and an open position, arranged in an extract air inlet end 16 of the exhaust air duct 6 for the extraction of used extract air A.sub.E from the room 35 into the exhaust air duct 6, and a by-pass valve 17, variable between a closed and an open position, arranged to connect the supply air duct 4 and the exhaust air duct 6 for the fluid connection of supply air A.sub.S in the event that the supply air valve 13 and the extract air valve 15 are closed. The supply air valve 13, the extract air valve 15 and the by-pass valve 17 are controlled by the control unit 10. The safety system 1 is further made up of an outdoor air valve 18, variable between a closed and an open position, arranged in an outdoor air inlet end 19 of the supply air duct 4 for the supply of supply air A.sub.S into the supply air duct 4, and an exhaust air valve 20, variable between a closed and an open position, arranged in an exhaust air outlet end 21 of the exhaust air duct 6 for the exhaust of used extract air A.sub.E from the exhaust air duct 6 to the ambient. The outdoor air valve 18 and the exhaust air valve 20 are controlled by the control unit 10. The compressor 36 is arranged within the exhaust air duct 6.

(15) FIGS. 6a, 6b and 6c show a safety system 1 for evacuation of contaminated air and prevention of ignition in an air handling system 2, according to an embodiment of the invention. The air handling system 2 is further made up of a compressor enclosure 22. The safety system 1 is further made up a compressor enclosure contamination sensor 23 arranged in the compressor enclosure 22 for collection of air contamination data 9, and a compressor enclosure duct unit 24 connected to the compressor enclosure 22 for evacuation of contaminated air from the compressor enclosure 22. A duct inlet 26 of the compressor enclosure duct unit 24 is arranged in a bottom part 27 of the compressor enclosure 22. An air supply inlet 28 for supply of air may be arranged in a top part 29, in a middle part 30 or in the bottom part 27 of the compressor enclosure 22.

(16) In FIG. 6c the compressor enclosure duct unit 24 is further made up of a compressor enclosure extract air unit 25. Contaminated air from the compressor enclosure is directly evacuated, for instance to the ambient

(17) In a step S100 air contamination data 9 is continuously retrieved by means of the air contamination sensor 8. In a step S110 the retrieved air contamination data 9 is compared to the predefined air contamination data threshold value 11 by means of the control unit 10. In a step S120, when a value v1 of a first contaminant in the retrieved air contamination data 9 is higher than the predefined air contamination data threshold value 11, the control unit 10 sends instructions to start the supply air unit 3 and the exhaust air unit 5, when said units 3, 5 are not operating, and to stop the compressor, when said compressor is operating. In a step S130, when a value v1 of a first contaminant in the retrieved air contamination data 9 is higher than the predefined air contamination data threshold value 11, the control unit 10 sends instructions to increase the speed of the supply air unit 3 and the exhaust air unit 5 to a predefined maximum speed 31, when said units 3, 5 are operating at a current speed 32 lower than a predefined speed 33, and to stop the compressor, when said compressor is operating. In a step S140, when a value v2 of the first contaminant in the retrieved air contamination data 9 is lower than the predefined air contamination data threshold value 11, the control unit 10 sends instructions to stop the supply air unit 3 and the exhaust air unit 5 after a predefined time 34.

(18) In a step S200 before step S120 and/or before step S130 the by-pass valve 17 is opened, the supply air valve 13 is closed, and the extract air valve 15 is closed.

(19) In a step S300 before step S120 and/or before step S130 the outdoor air valve 18 is opened. In a step S310 before step S120 and/or before step S130 the exhaust air valve 20 is opened.

(20) FIG. 10 shows a block diagram of a control system 10, comprising a processor 10.a, a user interface 10.b, a memory 10.c, and communication gateways 10.d. Through the communication gateways the control system can receive and send signals from/to other parts of the system. Through the user interface the control system can communicate with the user, through for instance a viewing screen, keyboard, mouse, printer, loud speaker, microphone or other type of peripheral. The computer program product can be stored in the memory, and be executed in the processor.

(21) The air to be treated passes through the evaporator/condenser coil in the air treatment space. The treated air is to be transferred to the premises where e.g. human beings are to be found. In the air treatment space or in said premises there should be no leaking refrigerant.

LIST OF COMPONENTS

(22) 1=safety system 2=air handling system 3=supply air unit 4=supply air duct 5=exhaust air unit 6=exhaust air duct 7=supply air contamination sensor 8=exhaust air contamination sensor 9=air contamination data 10=control unit 10.a=processor 10.b=user interface 10.c=memory 10.d=communication gateways 11=predefined air contamination data threshold value 12=power supply 13=supply air valve 14=supply air outlet end 15=extract air valve 16=extract air inlet end 17=by-pass valve 18=outdoor air valve 19=outdoor air inlet end 20=exhaust air valve 21=exhaust air outlet end 22=compressor enclosure 23=compressor enclosure contamination sensor 24=compressor enclosure duct unit 25=compressor enclosure extract air unit 26=duct inlet of the compressor enclosure duct unit 27=bottom part of the compressor enclosure 28=air supply inlet 29=top part of the compressor enclosure 30=middle part of the compressor enclosure 31=predefined maximum speed of the supply air unit and the exhaust air unit 32=current speed of the supply air unit and the exhaust air unit 33=a predefined speed of the supply air unit and the exhaust air unit 34=predefined time 35=room 36=compressor 37=refrigerant 38=evaporator/condenser coil v1, v2=value of a first contaminant in the retrieved air contamination data A.sub.S=supply air A.sub.E=used extract air