Water-cooled air conditioning system using condenser water regeneration for precise air reheat in dehumidifying mode

A regenerative condenser water reheat assembly for use with a water-cooled air conditioning system for conditioning air in an enclosed space and that is associated with a water source, the air conditioning system comprising a condenser adapted to conduct heat from a refrigerant to water and having a water inlet and a water outlet, an evaporator to conduct heat from air to refrigerant, a refrigerant circuit including a compressor and an expansion device and adapted to circulate refrigerant between the condenser and evaporator, a condenser water circuit including a supply conduit to circulate water from the water source to the water inlet of the condenser and a return conduit to circulate water from the water outlet of the condenser to the water source, and an air circuit adapted to receive return air from the space, to direct air through the evaporator, and to direct conditioned supply air to the space, the reheat assembly comprising:

• a reheat heat exchanger to conduct heat from water to air and adapted to be installed in the air circuit downstream of the evaporator, wherein the reheat heat exchanger has a water inlet and a water outlet;
• a regenerative condenser water reheat circuit adapted to circulate water from the return conduit of the condenser water circuit to the water inlet of the reheat heat exchanger and from the water outlet of the reheat heat exchanger to the supply conduit of the condenser water circuit;
• a reheat circulating pump to circulate water from the return conduit of the condenser water circuit to the water inlet of the reheat heat exchanger and from the water outlet of the reheat heat exchanger to the supply conduit of the condenser water circuit;
• and
• a control assembly comprising:
• a temperature sensor for detecting the temperature of the supply air entering the space;
• and
• a flow modulation assembly adapted to adjust the amount of water from the water source relative to the amount of water from the reheat circuit that is entering the condenser through the condenser water circuit supply conduit to maintain the supply air near a selected temperature.

A method for reheating supply air in a water-cooled air conditioning system for conditioning the air in an enclosed space and that is associated with a water source, wherein the air conditioning system comprises a condenser adapted to conduct heat from a refrigerant to water and having a water inlet and a water outlet, an evaporator adapted to conduct heat from air to refrigerant, a refrigerant circuit including a compressor and an expansion device and adapted to circulate refrigerant between the condenser and evaporator, a condenser water circuit including a supply conduit to circulate water from the water source to the water inlet of the condenser and a return conduit to circulate water from the water outlet of the condenser to the water source, and an air circuit adapted to receive return air from the space, to direct it through the evaporator, and to direct supply air into the space, the method comprising:

• in response to the temperature of the supply air leaving the air circuit, circulating a modulated amount of condenser water from the return conduit of the condenser water circuit in heat exchange relation with air in the air circuit downstream of the evaporator and then returning the modulated amount of condenser water to the supply conduit of the condenser water circuit, wherein the modulated amount of condenser water is selected to adjust the amount of water from the water source relative to the amount of water that is being returned to the condenser water circuit supply conduit to maintain the supply air near a selected temperature.