Combustible gas leakage protection device and control method for wide temperature range air heat source heat pump

Abstract

To provide a combustible gas leakage protection device and a control method capable of reducing a burden of a person in charge of operation and maintenance by preventing frequent stop of a system, avoiding an extreme energy consumption method of always executing an exhaust countermeasure from a leakage concern, and reducing power consumption of a heat pump system.SOLUTION: The refrigerator comprises a component compartment and a finned heat exchanger compartment 2 which are independently partitioned, and the component compartment comprises a refrigerating system compartment 3 and an engine compartment 4 which are independently partitioned. An engine 5 is installed in the engine room 4, a gas pipe 6 is connected to the engine 5, and a UPS explosion-proof power supply 13 is installed in the refrigerating system room 3. The control method can avoid frequent false alarms of an existing alarm system, execute an appropriate control instruction under different gas concentrations, and precisely control a gas leakage concentration for real-time correction. To reduce the burden of a person in charge of operation and maintenance by preventing the frequent stop of a system and to prevent the generation of unrecoverable damage due to gas leakage in an abnormal situation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention discloses a protection device for preventing flammable gas leakage, and more particularly relates to a protection device for preventing flammable gas leakage in a wide temperature range air source heat pump and a control method thereof. [Background technology]

[0002] A wide-temperature range air-source heat pump is an air conditioning system that uses gases such as natural gas, liquefied petroleum gas, and biogas as a high-quality driving energy source to operate an open-type compressor directly driven by a gas engine, completing a vapor compression refrigeration cycle to achieve heating and cooling. Compared to electric heat pumps (EHPs) that use electricity as a high-quality driving energy source, wide-temperature range air-source heat pumps are theoretically the same as electric heat pumps (EHPs), and use a highly efficient gas engine instead of an electric motor.

[0003] Fuel for gas engines includes flammable gases such as natural gas, liquefied petroleum gas, and biogas. Normally, when low-pressure gas is supplied to the engine through natural gas piping, there is no risk of leakage. However, if the engine compartment of a wide-temperature range air-source heat pump is in a nearly sealed environment, and gas leakage occurs after a long period of non-use, when the gas concentration in the engine compartment reaches a certain ratio, there is a possibility of serious danger from sparks caused by the operation of electrical equipment when the user starts the engine.

[0004] Flammable gas leak protection control can prevent danger by detecting gas leaks in advance and taking appropriate action depending on the system status and leak situation. The acceptable range of gas leaks is set within a certain range. If an alarm were to be issued immediately for a minor leak, alarms would be issued frequently, resulting in repeated system shutdowns, causing great inconvenience to operation and maintenance personnel and users. On the other hand, if exhaust fans are operated constantly to prevent leaks, more power than necessary would be consumed, compromising the low power consumption and energy-saving features of the equipment. Summary of the Invention

[0005] To solve the problem of flammable gas leakage protection and control in the wide temperature range air-source heat pump of the prior art, the present invention provides a flammable gas leakage protection device and control method for a wide temperature range air-source heat pump, which adopts a special air intake passage and control method. The air passage design of this device not only meets the functional requirements of the heat pump system itself, but also accommodates the discharge of flammable gas after leakage.

[0006] The technical solutions to solve the technical problems of the present invention are as follows: A flammable gas leakage protection device for a wide temperature range air-source heat pump has an independently partitioned parts chamber and a fin-type heat exchanger chamber. The parts room consists of a refrigeration system room and an engine room, which are independently partitioned. The engine room houses the engine and gas piping, and the refrigeration system room is equipped with an explosion-proof UPS power supply.

[0007] The above-mentioned method for controlling a flammable gas leakage protection device for a wide temperature range air-source heat pump mainly includes the following steps: Step S1: The sensor detects the current leaked gas concentration value P. Step S2: Determine whether the gas leakage concentration exceeds the reference value P1. If the concentration is less than P1, repeat steps S1 and S2. If the concentration exceeds P1, execute step S3. Step S3: Start the operation of the second controllable axial fan. Step S4: After time T1, it is determined whether the leaked gas concentration has exceeded the concentration value P2. If it has not exceeded the concentration value P2, step S2 is executed; if it has exceeded the concentration value P2, step S5 is executed. Step S5: Start the operation of the first controllable axial fan, issue an alarm signal to the outside, and close the gas shutoff solenoid valve. Step S6: It is determined whether the engine is in operation, and if it is in operation, step S7 is executed, and if it is not in operation, step S8 is executed. Step S7: Stop the engine. Step S8: After time T2, it is determined whether the leaked gas concentration has reached concentration value P3. If it has not reached concentration value P3, step S21 is executed, and if it has reached concentration value P3, step S9 is executed. Step S9: The first controllable axial fan is operated in reverse to suck air from the outside to the inside of the room, and the third controllable axial fan above the finned heat exchanger chamber is started to operate. Step S10: After time T4, it is determined whether the concentration has reached concentration value P4, and if it has reached concentration value P4, step S11 is executed. Step S11: Start the operation of the fourth controllable axial fan, and issue an alarm continuously. Step S12: The current control state is maintained for a time period T5. Step S13: Determine whether the density is less than density value P3. If it is less than density value P3, return to step S5; if it exceeds density value P3, execute step S9. Step S21: The current control state is maintained for a time period T3. Step S22: Determine whether the density is less than the density value P2. If it is less than the density value P2, return to step S3; if it exceeds the density value P2, continue with step S5.

[0008] The technical solutions of the present invention further include: A gas shutoff electromagnetic valve is connected to the gas pipe. The gas shutoff solenoid valve is installed in the engine compartment. A first controllable axial fan is installed on the side wall of the refrigeration system chamber. A bottom air intake grille is installed at the bottom of the refrigeration system chamber. A second controllable axial fan is installed on the side wall of the engine compartment, and a gas concentration protection and control device is fixedly installed in the engine compartment. A bottom intake grille is installed at the bottom of the engine compartment. The engine compartment and the fin-type heat exchanger compartment are in communication with each other via an air passage. A third controllable axial fan and a fourth controllable axial fan are installed above the finned heat exchanger chamber. [Effects of the Invention]

[0009] The beneficial effects of the present invention are as follows: We propose a new flammable gas leakage protection device and control method for existing wide-temperature range air-source heat pump air conditioning systems that can respond to gas leakage in emergency situations. The air duct design meets the functional requirements of the heat pump system itself and also accommodates the discharge of flammable gas after a leak. This control method can avoid the false alarms that frequently occur in conventional alarm systems and can execute appropriate control commands under different gas concentrations. By precisely controlling gas leakage concentrations and repeatedly correcting them in real time, it is possible to prevent frequent system shutdowns and reduce the burden on operation and maintenance personnel. Furthermore, it is possible to avoid extreme energy consumption such as constantly implementing exhaust measures due to concerns about leakage, thereby reducing the power consumption of the heat pump system. The system achieves low power consumption and energy conservation in both operating and standby states, while balancing accuracy and low power consumption, and prevents irreparable damage caused by gas leaks in abnormal situations.

[0010] The present invention will now be described in detail with reference to the drawings and specific embodiments. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic structural diagram of a wide temperature range air source heat pump and a flammable gas leakage protection device according to the present invention. [Figure 2] FIG. 4 is a diagram showing the flow direction of the air passage in a first control state in the present invention. [Figure 3] FIG. 10 is a diagram showing the flow direction of the air passage in the second control state in the present invention. [Figure 4] FIG. 10 is a diagram showing the flow direction of the air passage in a third control state in the present invention. [Figure 5] FIG. 10 is a diagram showing the flow direction of the air passage in a fourth control state in the present invention. [Figure 6]3 is a flowchart of a flammable gas leakage protection control according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present embodiment is a preferred embodiment of the present invention, and any other principles and basic structures that are the same or similar to those of the present embodiment are within the protection scope of the present invention.

[0013] See FIG. 1. The present invention primarily protects a flammable gas leakage protection device for a wide-temperature range air-source heat pump. The flammable gas leakage protection device for a wide-temperature range air-source heat pump includes an independently partitioned parts compartment and a fin-type heat exchanger compartment 2. The parts compartment includes an independently partitioned refrigeration system compartment 3 and an engine compartment 4. An engine 5 is installed in the engine compartment 4, and a gas pipe 6 is connected to the engine 5 and used to supply gas to the engine 5. In this embodiment, a gas shutoff solenoid valve 11 is connected to the gas pipe 6 and used to control the on / off of the gas pipe 6. The gas shutoff solenoid valve 11 is preferably installed in the engine compartment 4. A UPS explosion-proof power supply 13 is installed in the refrigeration system compartment 3, which also includes common refrigeration components such as a liquid storage tank, a gas-liquid separator, an oil separator, copper piping, a four-way valve, and an electronic expansion valve. These components are standard equipment for wide-temperature range air-source heat pumps and are not the gist of the present invention, so detailed descriptions are omitted.

[0014] In this embodiment, a first controllable axial fan 14 whose rotation speed and direction are adjustable is installed on the side wall of the refrigeration system room 3, and preferably the first controllable axial fan 14 is installed at a position closer to the lower side of the side wall of the refrigeration system room 3. A bottom intake grille 8 for ventilation is installed at the bottom of the refrigeration system room 3.

[0015] In this embodiment, a second controllable axial fan 15 with adjustable rotation speed and direction is installed on the side wall of the engine compartment 4, and preferably the second controllable axial fan 15 is installed at a position closer to the upper side wall of the engine compartment 4. A gas concentration protection control device 12 is fixed in the engine compartment 4, which detects the gas concentration in the engine compartment 4, sends a concentration signal, issues an alarm signal when the concentration reaches a set value, and controls the opening and closing of the gas shut-off solenoid valve 11 according to the gas concentration. A bottom intake grille 8 for ventilation is also installed at the bottom of the engine compartment 4.

[0016] In this embodiment, the engine compartment 4 and the fin type heat exchanger compartment 2 are communicated with each other through an air passage 7 .

[0017] In this embodiment, a third controllable axial fan 16 and a fourth controllable axial fan 17 are installed above the finned heat exchanger chamber 2, and the rotation speed and direction of the third controllable axial fan 16 and the fourth controllable axial fan 17 are adjustable.

[0018] In this embodiment, the UPS explosion-proof power supply 13 supplies power to the gas concentration protection control device 12, the first controllable axial fan 14, the second controllable axial fan 15, the third controllable axial fan 16, and the fourth controllable axial fan 17.

[0019] In this embodiment, as shown in FIG. 6, the present invention also provides a control method for a flammable gas leakage protection device for a wide temperature range air source heat pump, which mainly includes the following steps: Step S1: The sensor detects the current leaked gas concentration value P. Step S2: Determine whether the gas leak concentration exceeds a reference value P1 (in this embodiment, the reference value P1 is 500 ppm to 1500 ppm, and preferably 1000 ppm). If the concentration is less than the reference value P1, steps S1 and S2 are repeatedly executed to avoid causing danger and to avoid frequent activation of the alarm, which could lead to system malfunction. If the concentration exceeds the reference value P1, execute step S3. Step S3: Start the operation of the second controllable axial fan 15. At this time, the flow direction of the air passage is as shown in Figure 2, which corresponds to the first control state. The second controllable axial fan 15 operates to exhaust air from the engine compartment 4 to the outside environment, and the intake passage is the bottom intake grille 8 installed at the bottom. Step S4: After time T1 (in this embodiment, the selectable range of time T1 is 120 S to 240 S, preferably 200 S), determine whether the leaked gas concentration exceeds concentration value P2 (in this embodiment, concentration value P2 is 1600 ppm to 3000 ppm, more preferably 2200 ppm), and if it does not exceed concentration value P2, return to step S2; otherwise, execute step S5. Step S5: The first controllable axial fan 14 is started. At this time, the first controllable axial fan 14 and the second controllable axial fan 15 operate simultaneously and issue an alarm signal. The gas shutoff solenoid valve 11 is closed. The flow direction of the air duct at this time is as shown in FIG. 3, which is the second control state. The second controllable axial fan 15 and the first controllable axial fan 14 are started. The first controllable axial fan 14 draws air from the external environment, and the second controllable axial fan 15 exhausts air from the engine compartment 4 to the external environment. The first air duct flow enters through the first controllable axial fan 14, passes through the refrigeration system compartment 3, passes through the engine compartment 4, and is discharged from the second controllable axial fan 15. The second air duct flow enters through the bottom intake grille 8, passes through the refrigeration system compartment 3 and the engine compartment 4, and is discharged from the second controllable axial fan 15. Step S6: It is determined whether the engine 5 is in operation. If it is in operation, step S7 is executed, and if it is not in operation, step S8 is executed. Step S7: The engine 5 is stopped. Step S8: After time T2 (in this embodiment, the selectable range for time T2 is 100 S to 200 S, preferably 120 S) has elapsed, determine whether the leaked gas concentration has reached concentration value P3 (in this embodiment, the concentration value P3 is 3100 ppm to 4500 ppm, preferably 3500 ppm), and if the concentration value P3 has not been reached, execute step S21, and if the concentration value P3 has been reached, execute step S9. Step S9: At this time, the first controllable axial fan 14 is operated in reverse to draw air from the outside toward the inside of the room, and the third controllable axial fan 16 above the finned heat exchanger chamber is started. The flow direction of the air duct at this time is as shown in FIG. 4, which is the third control state. The first controllable axial fan 14 and the second controllable axial fan 15 draw air from the outside environment toward the refrigeration system chamber 3 and the engine chamber 4, and the third controllable axial fan 16 exhausts air from the finned heat exchanger chamber 2 toward the outside environment. The first air duct flow is the first controllable axial fan 14 and the second controllable axial fan 15 drawing air from the outside environment. The second air duct flow is the air drawn in from the outside environment passing through the bottom intake grille 8. Both the first and second air ducts pass through the ventilation passage 7 and are exhausted to the outside environment by the third controllable axial fan 16. Step S10: After a time T4 (in this embodiment, the selectable range for time T4 is 30 to 60 seconds, and preferably 40 seconds), it is determined whether the concentration has reached a concentration value P4 (in this embodiment, the concentration value P4 is 4600 ppm to 5200 ppm, and preferably 5000 ppm), and if the concentration value P4 has been reached, step S11 is executed. If the concentration value P4 has not been reached, the current control state is maintained, and detection continues. Step S11: The fourth controllable axial fan 17 is started, and a continuous alarm is issued to the maintenance personnel. The flow direction of the air duct at this time is as shown in FIG. 5, which is the fourth control state. The first controllable axial fan 14 and the second controllable axial fan 15 draw air from the external environment into the bottom component compartment. After passing through the ventilation passage 7, the third controllable axial fan 16 and the fourth controllable axial fan 17 exhaust the air to the external environment. At this time, the exhaust volume Q is greater than the gas leakage volume q, so the gas concentration does not reach the explosive limit concentration range. The first air duct flow is the first controllable axial fan 14 and the second controllable axial fan 15 drawing air from the external environment. The second air duct flow is the air drawn in from the external environment through the bottom intake grille 8. Both the first and second air ducts pass through the ventilation passage 7 and are exhausted to the external environment by the third controllable axial fan 16 and the fourth controllable axial fan 17. Step S12: The current control state is maintained for a time T5 (in this embodiment, the selectable range of the time T5 is 60 S to 120 S, and preferably 90 S). Step S13: Determine whether the density is less than density value P3. If it is less than density value P3, return to step S5; if it exceeds density value P3, execute step S9. Step S21: The current control state is maintained for a time T3 (in this embodiment, the selectable range of the time T3 is 70 S to 120 S, and preferably 90 S). Step S22: Determine whether the density is less than the density value P2. If it is less than the density value P2, return to step S3; if it exceeds the density value P2, continue with step S5.

[0020] This invention proposes a new flammable gas leak protection device and control method for existing wide-temperature range air-source heat pump air conditioning systems that can respond to gas leaks during abnormal situations. The air duct design satisfies the functional requirements of the heat pump system itself and is configured to accommodate the discharge of flammable gas after a leak. The control method of this invention avoids the frequent false alarms that conventional alarm systems issue and executes appropriate control commands under different gas concentrations. By precisely controlling gas leak concentrations and repeatedly correcting them in real time, it is possible to prevent frequent system shutdowns and reduce the burden on operation and maintenance personnel. Furthermore, it is possible to avoid extremely energy-intensive measures such as constant exhaust ventilation due to leak concerns, thereby reducing the power consumption of the heat pump system. It achieves low power consumption and energy savings in both operating and standby states, while balancing accuracy and low power consumption, preventing irreparable damage caused by gas leaks during abnormal situations. [Explanation of symbols]

[0021] 1 - Condensate tray for wide temperature range air source heat pump 2 - Finned heat exchanger chamber 3 - Refrigeration system room 4 - Engine compartment 5 - Engine 6 - Gas piping 7 - Ventilation passage 8 - Bottom intake grate 11-Gas shutoff solenoid valve 12-Gas concentration protection control device 13-UPS explosion-proof power supply 14-1st controllable axial fan 15-2nd controllable axial fan 16-Third controllable axial fan 17-4th controllable axial fan

Claims

1. A flammable gas leakage protection device for a wide temperature range air source heat pump, The heat exchanger includes a component chamber and a fin-type heat exchanger chamber (2) that are independently partitioned, a refrigeration system room (3) and an engine room (4) that are independently partitioned, an engine (5) is installed in the engine room (4), a gas pipe (6) is connected to the engine (5), a second controllable axial fan (15) is attached to a side wall of the engine room (4), a gas concentration protection control device (12) is fixedly installed in the engine room (4), a bottom air intake grille (8) is installed at the bottom of the engine room (4), the engine room (4) and the fin-type heat exchanger room (2) are mutually communicated through an air vent (7), a UPS explosion-proof power supply (13) is installed in the refrigeration system room (3), a first controllable axial fan (14) is installed at the side wall of the refrigeration system room (3), and a bottom air intake grille (8) is installed at the bottom of the refrigeration system room (3).

2. 2. The flammable gas leakage protection device for a wide temperature range air-source heat pump according to claim 1, wherein a gas shutoff solenoid valve (11) is connected to the gas piping (6).

3. 3. The flammable gas leakage protection device for a wide temperature range air-source heat pump according to claim 2, wherein the gas shutoff solenoid valve (11) is installed in an engine compartment (4).

4. The flammable gas leakage protection device for a wide temperature range air-source heat pump according to claim 1, characterized in that a third controllable axial fan (16) and a fourth controllable axial fan (17) are installed on the upper part of the fin-type heat exchanger chamber (2).

5. A method for controlling a flammable gas leakage protection device for a wide temperature range air-source heat pump according to any one of claims 1 to 4, comprising: Step S1: The sensor detects the current leaked gas concentration value P, Step S2: Determine whether the gas leakage concentration exceeds the reference value P1. If the concentration is less than P1, repeat steps S1 and S2. If the concentration exceeds P1, execute step S3. Step S3: Start the operation of the second controllable axial fan (15); Step S4: After the time T1, determine whether the leaked gas concentration has exceeded the concentration value P2. If it has not exceeded the concentration value P2, return to step S2. If it has exceeded the concentration value P2, execute step S5. Step S5: Start the operation of the first controllable axial flow fan (14), issue an alarm signal to the outside, and close the gas shutoff solenoid valve (11); Step S6: Determine whether the engine (5) is in operation. If it is in operation, execute step S7. If it is not in operation, execute step S8. Step S7: Stop the engine (5), Step S8: After the time T2, it is determined whether or not the leaked gas concentration has reached the concentration value P3. If the concentration value P3 has not been reached, step S21 is executed. If the concentration value P3 has been reached, step S9 is executed. Step S9: The first controllable axial flow fan (14) is operated in reverse to suck air from the outside to the inside of the room, and the third controllable axial flow fan (16) above the finned heat exchanger chamber is started to operate. Step S10: After the time T4, it is determined whether the concentration has reached a concentration value P4. If the concentration has reached the concentration value P4, step S11 is executed. Step S11: Start the operation of the fourth controllable axial fan (17) and issue a warning continuously; Step S12: Maintain the current control state for T5 time; Step S13: Determine whether the density is less than the density value P3. If it is less than the density value P3, return to step S5. If it exceeds the density value P3, execute step S9. Step S21: Maintain the current control state for a time period T3; Step S22: Determine whether the density is less than the density value P2. If it is less than the density value P2, return to step S3. If it exceeds the density value P2, continue with step S5. A control method comprising the above steps.

Images