Systems and methods for charging refrigerant into a climate control system

Patent metadata

Field	Value
Publication number	US-11506433-B2
Application number	US-202016804769-A
Country	US
Kind code	B2
Filing date	Feb 28, 2020
Priority date	Feb 28, 2020
Publication date	Nov 22, 2022
Grant date	Nov 22, 2022

Abstract

Methods and related systems for charging a refrigerant into a climate control system. In an embodiment, the method includes (a) coupling a storage tank to a refrigerant loop of the climate control system through a charging valve; (b) opening and closing the charging valve in a plurality of cycles; and (c) flowing refrigerant from the storage tank to the refrigerant loop through the charging valve when the charging valve is open, during (b). In addition, the method includes (d) determining a detected saturated temperature of the refrigerant within the refrigerant loop after each cycle of the plurality of cycles; and (e) adjusting an amount of time that the charging valve is open during each cycle of the plurality of cycles during (b) as a function of the detected saturated temperature from a previous cycle of the plurality of cycles.

First claim

What is claimed is:

1. A method of charging a refrigerant into a climate control system, the method comprising:
(a) coupling a storage tank to a refrigerant loop of the climate control system through a charging valve;
(b) opening and closing the charging valve in a plurality of cycles;
(c) flowing refrigerant from the storage tank to the refrigerant loop through the charging valve when the charging valve is open, during (b);
(d) determining a detected saturated temperature of the refrigerant within the refrigerant loop after each cycle of the plurality of cycles; and
(e) adjusting an amount of time that the charging valve is open during each cycle of the plurality of cycles during (b) as a function of the detected saturated temperature from a previous cycle of the plurality of cycles.

2. The method of claim 1 , wherein (e) comprises adjusting the amount of time that the charging valve is open during each cycle during (b) as a function of a difference between a target saturated temperature and the detected saturated temperature from the previous cycle of the plurality of cycles.

3. The method of claim 2 , comprising detecting a pressure of the refrigerant at a discharge side of a heat exchanger of an outdoor unit of the climate control system, wherein (e) comprises determining the detected saturated temperature based on the pressure.

4. The method of claim 3 , comprising determining the target saturated temperature based on a predetermined relationship between the detected saturated temperature and a liquid temperature of the refrigerant loop, wherein the liquid temperature of the
refrigerant loop is determined at the discharge side of the heat exchanger of the outdoor unit of the climate control system.

5. The method of claim 4 , wherein the predetermined relationship is derived based on a full charge of refrigerant within the refrigerant loop.

6. The method of claim 2 , wherein (e) comprises adjusting the amount of time that the charging valve is open during each cycle during (b) as a function of the difference between the target saturated temperature and the detected saturated temperature, and a time derivative of the difference.

7. The method of claim 6 , wherein (e) comprises adjusting a duty cycle of the charging valve during each cycle during (b) according to the following expression:

Duty
⁢

⁢
Cycle

=

(

DC
nom

)

⁢

(

K
P

)

⁢

(

Δ
⁢

⁢

T
SAT

)

+

(

K
D

)

⁢

(

d
⁡

(

Δ
⁢

⁢

T
SAT

)

dt

)

,

wherein DC nom comprises a nominal duty cycle value, ΔT SAT comprises the difference between the target saturated temperature and the detected saturated temperature,

d
⁡

(

Δ
⁢

⁢

T
SAT

)

dt

comprises the time derivative of ΔT SAT , and K P and K D comprise constant values.

8. The method of claim 7 , comprising limiting the duty cycle of the charging valve during each cycle during (b) to a predetermined amount of time that is less than a total time of each cycle.

9. The method of claim 8 , wherein each of the plurality of cycles has a fixed duration.

10. The method of claim 2 , comprising determining the target saturated temperature based on at least one of:
a length of a fluid flow line of the climate control system; or
a difference in elevation between an outdoor unit and an indoor unit of the climate control system.

11. The refrigerant charging system of claim 10 , comprising: a pressure sensor coupled to the controller; and
a temperature sensor coupled to the controller;
wherein the pressure sensor and the temperature sensor are configured to be coupled to the refrigerant loop; and
wherein the controller is configured to:
determine the detected saturated temperature of the refrigerant based on a pressure measurement within the refrigerant loop by the pressure sensor;
determine a target saturated temperature as a function of a temperature measurement within the refrigerant loop by the temperature sensor; and
adjust the amount of time the charging valve is open during each cycle of the plurality of cycles as a function of a difference between the target saturated temperature and the detected saturated temperature.

12. The refrigerant charging system of claim 11 , wherein the controller is configured to adjust a duty cycle of the charging valve during each cycle of the plurality of cycles to adjust the amount of time the charging valve is open during each cycle, wherein the controller is configured to adjust the duty cycle of the charging valve according to the following expression:

Duty
⁢

⁢
Cycle

=

(

DC

Assignees

• Trane Int Inc

Inventors

• Rite Raymond Walter
• Whitehurst Drew
• Smith Nathan

Classifications

• F25B2345/001

  Charging refrigerant to a cycle · CPC title

• F25B45/00 Primary

  Arrangements for charging or discharging refrigerant · CPC title

• F25B2345/003

  Control issues for charging or collecting refrigerant to or from a cycle · CPC title

• F25B2700/21163

  of the refrigerant at the outlet of the condenser · CPC title

• F25B2700/195

  of the condenser · CPC title