Heat Pump Systems with Reheat Features

Abstract

Vapor compression cycle systems with a de-humidification or reheat feature are disclosed. Embodiments of such a vapor compression cycle system may include a compressor, a first valve coupled to an output and an input of the compressor, a second valve coupled to the output of the compressor and to the first valve, a first heat exchanger coupled between the second valve and a third valve, a second heat exchanger coupled between the first valve and the third valve, a first solenoid valve coupled to the second heat exchanger and a first end of a reheat coil, a second solenoid valve coupled to the first end of the reheat coil and a fourth valve, a second end of the reheat coil coupled to the second valve, and the fourth valve coupled to the first heat exchanger after the second valve.

That which is claimed is: 
     
         1 . A vapor compression cycle system comprising:
 a compressor;   a first valve coupled to an output and an input of the compressor;   a second valve coupled to the output of the compressor and to the first valve;   a first heat exchanger coupled between the second valve and a third valve;   a second heat exchanger coupled between the first valve and the third valve;   a first solenoid valve coupled to the second heat exchanger and a first end of a reheat coil;   a second solenoid valve coupled to the first end of the reheat coil and a fourth valve;   a second end of the reheat coil coupled to the second valve; and   the fourth valve coupled to the first heat exchanger after the second valve;   wherein the vapor compression cycle system is configured to, in a first mode:
 close the second solenoid valve; 
 place the second valve in a first state such that the second valve prevents flow of first fluid from the reheat coil to the compressor via the second end of the reheat coil; 
 open the first solenoid valve for a first period of time causing a first portion of the first fluid to flow from the second heat exchanger to the reheat coil; 
 cause a second portion of the first fluid to flow from the second heat exchanger to the compressor via the first heat exchanger and the third valve; and 
 close the first solenoid valve after expiration of the first period of time. 
   
     
     
         2 . The vapor compression cycle system of  claim 1 , wherein in a second mode, the vapor compression cycle system is configured to:
 open the first solenoid valve;   cause a third portion of the fluid to flow from the compressor to the second heat exchanger via the first heat exchanger and the third valve; and   cause the first portion of the fluid to flow from the reheat coil to the compressor via the second heat exchanger.   
     
     
         3 . The vapor compression cycle system of  claim 2 , wherein a first pressure inside the second heat exchanger is lower than a second pressure outside the second heat exchanger. 
     
     
         4 . The vapor compression cycle system of  claim 1 , wherein in a second mode, the vapor compression cycle system is configured to:
 open the second solenoid valve;   place the second valve in a second state such at it allows flow of fluid from the compressor to the reheat coil via the second end of the reheat coil;   cause a third portion of the fluid to flow from the compressor to the reheat coil via the second valve;   cause the third portion of the fluid to flow from the reheat coil to the first heat exchanger via the second solenoid valve; and   cause the third portion of the fluid to flow from the first heat exchanger to the compressor via the third valve and the second heat exchanger.   
     
     
         5 . The vapor compression cycle system of  claim 4 , wherein the portion of the fluid in the reheat coil is at a first temperature that is higher than a second temperature of the third portion of the fluid. 
     
     
         6 . The vapor compression cycle system of  claim 1 , wherein the portion of the fluid in the reheat coil is in a liquid form. 
     
     
         7 . The vapor compression cycle system of  claim 1 , further comprising:
 a first fan configured to blow a second fluid across the first heat exchanger; and   a second fan configured to blow the second fluid across the reheat coil.   
     
     
         8 . The vapor compression cycle system of  claim 1 , wherein during the first mode, the first portion of the first fluid remains in the reheat coil. 
     
     
         9 . A vapor compression cycle system comprising:
 a compressor;   a first valve coupled to an output and an input of the compressor;   a second valve coupled to the output of the compressor and to the first valve;   a first heat exchanger coupled between the second valve and a third valve;   a second heat exchanger coupled between the first valve and the third valve;   a first solenoid valve coupled to the second heat exchanger and a first end of a reheat coil;   a second solenoid valve coupled to the first end of the reheat coil and a fourth valve;   a second end of the reheat coil coupled to the second valve; and   the fourth valve coupled to the first heat exchanger after the second valve;   wherein the vapor compression cycle system is configured to, in a first mode:
 close the first solenoid valve; 
 open the second solenoid valve; 
 place the second valve in a first state such at it allows flow of fluid from the compressor to the reheat coil via the second end of the reheat coil; 
 cause a first portion of the fluid to flow from the compressor to the reheat coil via the second valve; 
 heat the first portion of the fluid in the reheat coil to a first temperature; 
 cause the first portion of the fluid to flow from the reheat coil to the first heat exchanger via the second solenoid valve; and 
 cause the first portion of the fluid to flow from the first heat exchanger to the compressor via the third valve and the second heat exchanger. 
   
     
     
         10 . The vapor compression cycle system of  claim 9 , further configured to:
 cause a second fluid to traverse across the second heat exchanger and the reheat coil, wherein the second fluid has a first temperature prior to traversing across the reheat coil and has a second temperature after traversing the reheat coil.   
     
     
         11 . The vapor compression cycle system of  claim 10 , wherein the first temperature is lower than the second temperature. 
     
     
         12 . The vapor compression cycle system of  claim 10 , further comprising:
 a first fan unit coupled to the first heat exchanger; and   a second fan unit coupled to the reheat coil, wherein the second fan unit is configured to deliver the second fluid, after it traverses the reheat coil, to an indoor space.   
     
     
         13 . The vapor compression cycle system of  claim 9 , further configured to, in the first mode, cause a second fluid to traverse across the second heat exchanger and the reheat coil, wherein the second fluid has a first humidity value prior to traversing across the second heat exchanger and has a second humidity value after traversing the second heat exchanger. 
     
     
         14 . The vapor compression cycle system of  claim 13 , wherein the first humidity value is higher than the second humidity value. 
     
     
         15 . The vapor compression cycle system of  claim 9 , wherein the reheat coil is placed adjacent to the second heat exchanger. 
     
     
         16 . A vapor compression cycle system comprising:
 a compressor;   a reheat coil circuit, the reheat coil circuit comprising:
 one or more valves for controlling a flow of refrigerant through the reheat coil circuit; and 
 a reheat coil; 
   an indoor heat exchanger in fluid communication with the compressor and positioned in an airflow pathway with the reheat coil;   a valve positioned between the indoor heat exchanger and the reheat coil; and   a controller configured to control operation of the vapor compression cycle system in a plurality of modes, wherein in a first mode, the controller is configured to operate the one or more valves for controlling the flow of refrigerant through the reheat coil to prevent refrigerant from flowing through the reheat coil, open the valve for a first period of time, and close the valve after the first period of time.   
     
     
         17 . The vapor compression cycle system of  claim 16 , wherein the compressor is configured to circulate a volume of refrigerant through the vapor compression cycle system, wherein a first portion of the volume of refrigerant is stored in the reheat coil while the valve is open and is retained in the reheat coil while the valve is closed. 
     
     
         18 . The vapor compression cycle system of  claim 17 , wherein the first portion of the volume of refrigerant is stored in the reheat coil as a liquid. 
     
     
         19 . The vapor compression cycle system of  claim 16 , wherein in a second mode, the controller is configured to close the valve and open the one or more valves for controlling the flow of refrigerant through the reheat coil circuit. 
     
     
         20 . The vapor compression cycle system of  claim 19 , wherein the one or more valves for controlling the flow of refrigerant through the reheat coil circuit comprise:
 a three-way valve positioned between the compressor and an outdoor heat exchanger, wherein in the second mode, the controller is configured to place the three-way valve in a first state to direct refrigerant from the compressor to the reheat coil; and   a second valve positioned between the reheat coil and the outdoor heat exchanger, wherein in the second mode, the controller is configured to open the second valve to direct refrigerant from the reheat coil to the outdoor heat exchanger.