Valve unit for a heat-pump system and method for assembling the same
View Patent ↗A valve unit for a heat-pump system, includes: a liquid refrigerant pipe portion; a gas refrigerant pipe portion; a liquid control valve disposed in the liquid refrigerant pipe portion; a gas control valve disposed in the gas refrigerant pipe portion; a casing accommodating the liquid control valve and the gas control valve; and an air-discharge mechanism that discharges air in an internal space of the casing to an external space outside the casing in response to a refrigerant leakage in the casing.
1. A valve unit for a heat-pump system including a liquid refrigerant pipe and a gas refrigerant pipe, the valve unit comprising:
a liquid refrigerant pipe portion of the liquid refrigerant pipe;
a gas refrigerant pipe portion of the gas refrigerant pipe, wherein
the liquid refrigerant pipe and the gas refrigerant pipe both extend between a heatsource-side heat exchanger in a heatsource-side unit and a utilization-side heat exchanger in a utilization-side unit;
a liquid control valve disposed in the liquid refrigerant pipe portion;
a gas control valve disposed in the gas refrigerant pipe portion;
a casing that has an intake opening and a discharge opening and that accommodates the liquid control valve and the gas control valve; and
an air-discharge mechanism that comprises:
a check air damper mounted at the intake opening of the casing and that allows air to flow from an outside of the casing towards an internal space of the casing through the intake opening of the casing;
a fan that is disposed outside the casing, that comprises a suction port and a discharge port facing an outdoor space, and that draws air from the internal space of the casing towards the outdoor space; and
an air duct that connects the discharge opening of the casing to the suction port of the fan, wherein
the air-discharge mechanism discharges the air in the internal space of the casing to the outdoor space in response to a refrigerant leakage in the casing by operating the fan and keeping the check air damper in an open position.
2. The valve unit according to claim 1 , further comprising:
a sensor that measures a concentration of a refrigerant in the air in the casing; and
a controller that:
determines that the refrigerant leakage in the casing has occurred when the measured concentration is equal to or greater than a detection value threshold, and
controls the air-discharge mechanism to start discharge of the air when the refrigerant leakage has occurred.
3. The valve unit according to claim 2 , wherein the controller controls the liquid control valve and the gas control valve to close in response to a refrigerant leakage in a utilization-side piping section that extends between the liquid control valve and the gas control valve and that comprises a utilization-side heat exchanger.
4. The valve unit according to claim 3 , wherein the controller outputs alarm information in response to occurrence of the refrigerant leakage in the casing or in response to occurrence of the refrigerant leakage in the utilization-side piping section.
5. The valve unit according to claim 2 , wherein
the casing comprises an opening,
the air-discharge mechanism further comprises a check air damper that allows air to flow from an outside of the casing towards the internal space through the opening when the fan draws the air,
the check air damper is configured to be operated by an electric motor, and
the controller controls the electric motor to open the check air damper in response to occurrence of the refrigerant leakage in the casing.
6. The valve unit according to claim 1 , wherein
the gas refrigerant pipe portion comprises:
a low-pressure gas pipe portion;
a high-pressure gas pipe portion; and
a utilization-side gas pipe portion branching into the low-pressure gas pipe portion and the high-pressure gas pipe portion,
the liquid control valve comprises a liquid shut-off valve in the liquid refrigerant pipe portion, and
the gas control valve comprises:
a low-pressure gas control valve in the low-pressure gas pipe portion;
a high-pressure gas control valve in the high-pressure gas pipe portion; and
a gas shut-off valve in the utilization-side gas pipe portion.
7. The valve unit according to claim 6 , wherein at least one of the low-pressure gas control valve and the high-pressure gas control valve comprises a minute channel that enables refrigerant to flow through the minute channel even when an opening degree of the at least one of the low-pressure gas control valve and the high-pressure gas control valve is set to be lowest.
8. The valve unit according to claim 1 , wherein
the liquid refrigerant pipe portion comprises:
utilization-side liquid pipe portions; and
a heatsource-side liquid pipe portion branching into the utilization-side liquid pipe portions,
the gas refrigerant pipe portion comprises:
utilization-side gas pipe portions; and
a heatsource-side gas pipe portion branching into the utilization-side gas pipe portions,
the liquid control valve comprises liquid shut-off valves each disposed in each of the utilization-side liquid pipe portions,
the gas control valve comprises gas shut-off valves each disposed in each of the utilization-side gas pipe portions.
9. The valve unit according to claim 1 , wherein
the liquid refrigerant pipe portion comprises:
utilization-side liquid pipe portions; and
a heatsource-side liquid pipe portion branching into the utilization-side liquid pipe portions,
the gas refrigerant pipe portion comprises:
low-pressure gas sub pipes;
a low-pressure gas pipe portion branching into the low-pressure gas sub pipes;
high-pressure gas sub pipes;
a high-pressure gas pipe portion branching into the high-pressure gas sub pipes; and
utilization-side gas pipe portions each branching into one of the low-pressure gas sub pipes and one of the high-pressure gas sub pipes such that each of the utilization-side gas pipe portions is connected to the low-pressure gas pipe portion and the high-pressure gas pipe portion via the one of the low-pressure gas sub pipes and the one of the high-pressure gas sub pipes,
the liquid control valve comprises liquid shut-off valves each disposed in each of the utilization-side liquid pipe portions, and
the gas control valve comprises:
low-pressure gas control valves each disposed in each of the low-pressure gas sub pipes;
high-pressure gas control valves each disposed in each of the high-pressure gas sub pipes; and
gas shut-off valves each disposed in each of the utilization-side gas pipe portions.
10. The valve unit according to claim 1 , further comprising insulators applied to the casing such that the insulators isolate the internal space of the casing from an outer space surrounding the casing when the air-discharge mechanism is not discharging the air.
11. The valve unit according to claim 1 , wherein a refrigerant is R32 refrigerant.
12. A method for assembling the valve unit according to claim 1 , wherein the casing is made of casing parts, comprising:
disposing the casing parts around the liquid control valve and the gas control valve; and
fixing the casing parts to each other.
13. The method according to claim 12 , further comprising attaching the air-discharge mechanism to the casing.
14. The valve unit according to claim 1 , wherein the check air damper is configured to prevent an internal air from flowing out through the opening when the fan is not in operation.
15. The valve unit according to claim 1 , wherein the check air damper comprises a flap in an air path through the opening.
16. A valve unit for a heat-pump system including a liquid refrigerant pipe and a gas refrigerant pipe, the valve unit comprising:
a liquid refrigerant pipe portion of the liquid refrigerant pipe;
a gas refrigerant pipe portion of the gas refrigerant pipe, wherein
the liquid refrigerant pipe and the gas refrigerant pipe both extend between a heatsource-side heat exchanger in a heatsource-side unit and a utilization-side heat exchanger in a utilization-side unit;
a liquid control valve disposed in the liquid refrigerant pipe portion;
a gas control valve disposed in the gas refrigerant pipe portion;
a casing that has an intake opening and a discharge opening and that accommodates the liquid control valve and the gas control valve; and
an air-discharge mechanism that comprises:
a check air damper mounted at the intake opening of the casing and that allows air to flow from an outside of the casing towards an internal space of the casing through the intake opening of the casing;
a fan that is disposed inside the casing, that comprises a discharge port facing an outdoor space, and that draws air from the internal space of the casing towards the outdoor space; and
an air duct that connects the discharge port of the fan to the discharge opening of the casing, wherein
the air-discharge mechanism discharges the air in the internal space of the casing to the outdoor space in response to a refrigerant leakage in the casing by operating the fan and keeping the check air damper in an open position.