Electrical Box Sealing in Heat Pumps Against Refrigerant Ingress
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Solution Overview
Problem
In heat pump apparatuses, refrigerant leaks can enter the electrical equipment box, posing a risk of refrigerant exposure and ignition.
Innovation Solution
The heat pump apparatus includes an electrical equipment box with a terminal block and a window opening sealed by a flat-plate-shaped rubber packing, and a cover member attached via an O-ring, preventing refrigerant ingress from the refrigerant circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the electrical equipment box is opened for maintenance or wiring, then accessibility and ease of operation are improved, but refrigerant can enter the electrical equipment box causing safety hazards
Solution Approach 1:
The electrical equipment box is segmented into two parts: a fixed box body and a removable cover member. This allows the cover to be opened for maintenance while the box body remains sealed against refrigerant intrusion through the sealed connection interface.
Solution Approach 2:
A sealing material is introduced as an intermediary element between the cover member and the box body. This sealing material prevents refrigerant from entering the electrical equipment box while allowing the cover to be removed for maintenance purposes.
2Object-affected harmful factors
If a sealed structure is used to prevent refrigerant ingress, then safety is improved, but accessibility for maintenance becomes difficult
Solution Approach 1:
The sealed structure is divided into a removable cover member and a fixed box body. The cover can be detached for maintenance while the sealed connection between the cover and box body prevents refrigerant ingress during normal operation.
Solution Approach 2:
The sealing material acts as an intermediary that maintains the seal during operation but allows for controlled access during maintenance by removing the cover member.
3Ease of operation
If the terminal block is exposed for easy wiring, then ease of operation is improved, but refrigerant can reach electrical components causing ignition risk
Solution Approach 1:
The electrical equipment box is divided into a sealed box body containing the terminal block and a removable cover. The terminal block remains accessible within the sealed enclosure for wiring while the seal prevents refrigerant from reaching electrical components.
Solution Approach 2:
The sealing material serves as an intermediary barrier that protects electrical components from refrigerant while maintaining accessibility for wiring operations through the removable cover design.
Data Source
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AI summary
There is provided a heat pump apparatus that prevents a refrigerant, which has leaked from the refrigerant circuit, from entering an electrical equipment box. A heat pump apparatus 1 includes a machine room 13 and a blower room 12 each in a housing 10, the machine room 13 being a room in which a compressor 22 and an expansion device 24 are disposed, the blower room 12 being a room in which a heat exchanger 20 and a blower device 21 are disposed. The heat pump apparatus 1 includes an electrical equipment box 30; the electrical equipment box 30 includes an electrical equipment box body 32 and a cover member 33; and the electrical equipment box body 32 includes a terminal block 51 for cable (main power line) 45, a window opening 152 that the terminal block 51 faces, and a window cover body 155 that can seal the window opening 152 with a sealing material interposed therebetween.