Methods to Eliminate High Pressure Surges in HVAC Systems

Abstract

A system and method are disclosed for relieving high pressure within an HVAC system. A bypass line is provided that can direct refrigerant away from an expansion device within the HVAC system. The bypass line then returns the refrigerant to the HVAC system. Other locations of bypass lines can be used as well. A controller for the HVAC system can control access to the bypass line and measure pressure within the system.

Description

TECHNICAL FIELD[0001]The present disclosure is directed to HVAC systems and more particularly to pressure relief for these systems.BACKGROUND OF THE INVENTION[0002]HVAC systems may have pressure sensitivities during operation. For example, air conditioners may include microchannel condensers (e.g., condenser with a channel size less than approximately 1 mm) rather than other types of condensers (e.g., condenser with tube size greater than 5 mm). The buildup of refrigerant pressure in HVAC systems is a common problem. The problem can be particularly acute in systems with a microchannel condenser because microchannel condensers may be sensitive to certain operating conditions. For example, when ambient temperatures (e.g., temperatures proximate a condenser or temperature proximate a condenser fan) are high, the pressure in the microchannel condenser may become elevated due to the refrigerant capacity size difference between the microchannel condenser and the evaporator. The high press...

AI Technical Summary

Benefits of technology

The patent is about a method to reduce pressure in an HVAC system. It involves opening a bypass line to divert refrigerant away from an expansion valve, and then closing the bypass line when a certain condition is met. This method can help improve the performance of the HVAC system.

Problems solved by technology

The buildup of refrigerant pressure in HVAC systems is a common problem.

The problem can be particularly acute in systems with a microchannel condenser because microchannel condensers may be sensitive to certain operating conditions.

The high pressures (e.g., pressures greater than approximately 615 psi, in some embodiments) may cause mechanical failure, including prefailure events, such as excessive wear on parts.

High pressures may also trip safety systems designed to prevent overpressure.

However, this solution leads to a loss in cooling capacity or efficiency.

A particular problem can occur upon startup of an HVAC system.

Refrigerant may not be evenly / properly distributed within the system, leading to refrigerant and / or pressure imbalances.

However, this may limit other properties or capabilities of the system, and such a solution may not be feasible as a retrofit solution.

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