Heat recovery system and method for make-up air units

Abstract

This invention relates to a heat recovery system for an outdoor air conditioning unit, comprising an outdoor air conditioning unit, a first enthalpy measurement unit, a second enthalpy measurement unit, and a control unit. The first and second enthalpy measurement units are used to measure the enthalpy and temperature of the gas passing through the input and output terminals of the outdoor air conditioning unit, respectively, and generate a first temperature, a second temperature, a first enthalpy, and a second enthalpy. When the control unit determines that the first enthalpy is greater than the second enthalpy and the first temperature is greater than the second temperature, the control unit connects the first and second heating coils of the outdoor air conditioning unit, allowing the fluid to circulate between the first and second heating coils, which helps reduce the energy consumption of the outdoor air conditioning unit.

Claims

1. A heat recovery system for an outdoor air conditioning unit, comprising: An outdoor air conditioning unit includes a main body, a first heating coil, a second heating coil, at least one cooling coil, at least one filter unit, and an air supply unit. The first heating coil, the second heating coil, the cooling coil, the filter unit, and the air supply unit are disposed within the main body. The main body includes an input end and an output end. At least one fluid supply unit is connected to the first heating coil and the second heating coil of the outdoor air conditioning unit and is used to transport fluid to the first heating coil and the second heating coil. A first input line and a first output line are connected to the first heating coil and the fluid supply unit, wherein the fluid supply unit transports the fluid to the first heating coil via the first input line. A second input line and a second output line are connected to the second heating coil and the fluid supply unit, wherein the fluid supply unit transports the fluid to the second heating coil via the second input line. A first connecting line is connected to the first output line and the second input line. A second connecting pipeline connects the first input pipeline and the second output pipeline, wherein at least one valve is provided on the first input pipeline, the first output pipeline, the second input pipeline, the second output pipeline, the first connecting pipeline, or the second connecting pipeline; a first enthalpy measuring unit is used to measure the enthalpy and temperature of a gas entering the outdoor air conditioning unit from the input terminal, so as to generate a first enthalpy and a first temperature; A second enthalpy measuring unit is used to measure the enthalpy and temperature of the gas leaving the outdoor air conditioning unit from the output terminal, so as to generate a second enthalpy and a second temperature; and a control unit is connected to the first enthalpy measuring unit and the second enthalpy measuring unit, wherein when the first enthalpy is greater than the second enthalpy and the first temperature is greater than the second temperature, the control unit will control the fluid supply unit to stop supplying the fluid to the first heating coil and the second heating coil through the valve, and make the first heating coil and the second heating coil connected, wherein the fluid will circulate between the first heating coil and the second heating coil.

2. The heat recovery system of the outdoor air conditioning unit as claimed in claim 1, wherein the valve includes at least one first control valve, at least one second control valve and at least one connecting valve, the first control valve is disposed on the first input line, the second control valve is disposed on the second input line, and the connecting valve is connected to the first connecting line.

3. The heat recovery system of the outdoor air conditioning unit as described in claim 2, wherein the control unit is connected to the first control valve, the second control valve and the connecting valve, and when the first enthalpy value is greater than the second enthalpy value and the first temperature is greater than the second temperature, the control unit closes the first control valve and the second control valve and opens the connecting valve, so that the fluid circulates between the first heating coil and the second heating coil through the first connecting pipeline and the second connecting pipeline.

4. The heat recovery system of the outdoor air conditioning unit as claimed in claim 1, wherein the valve includes at least one first control valve, at least one second control valve, a first three-way valve and a second three-way valve, the first control valve being connected to the first input line, the second control valve being connected to the second input line, the first three-way valve being located between the fluid supply unit and the first heating coil and being connected to the first connecting line, and the second three-way valve being located between the fluid supply unit and the second heating coil and being connected to the first connecting line.

5. The heat recovery system of the outdoor air conditioning unit as described in claim 4, wherein the control unit is connected to the first control valve, the second control valve, the first three-way valve and the second three-way valve, and when the first enthalpy value is greater than the second enthalpy value and the first temperature is greater than the second temperature, the control unit closes the first control valve and the second control valve and switches the first three-way valve and the second three-way valve, so that the fluid circulates between the first heating coil and the second heating coil through the first connecting pipeline and the second connecting pipeline.

6. The heat recovery system of the outdoor air conditioning unit as claimed in claim 1, comprising at least one variable frequency pump disposed on the first connecting pipeline, the control unit connected to the variable frequency pump, wherein the first heating coil is connected to the second heating coil, and the fluid circulates between the first heating coil and the second heating coil, and the control unit adjusts the flow rate of the fluid between the first heating coil and the second heating coil through the variable frequency pump according to the first enthalpy value and the second enthalpy value.

7. The heat recovery system of the outdoor air conditioning unit as claimed in claim 1, wherein when the first enthalpy value is less than the second enthalpy value, or the first temperature is less than the second temperature, the control unit disconnects the connection between the first heating coil and the second heating coil, and causes the fluid supply unit to deliver the fluid to the first heating coil and the second heating coil.

8. A heat recovery method for an outdoor air conditioning unit, the outdoor air conditioning unit comprising a first heating coil and a second heating coil, comprising: The system detects the enthalpy and temperature of a gas entering the outdoor air conditioning unit and generates a first enthalpy and a first temperature; it detects the enthalpy and temperature of the gas leaving the outdoor air conditioning unit and generates a second enthalpy and a second temperature; it compares the first enthalpy and the second enthalpy, and the first temperature and the second temperature; and when the first enthalpy is greater than the second enthalpy and the first temperature is greater than the second temperature, it connects the first heating coil and the second heating coil, so that a fluid circulates between the first heating coil and the second heating coil.

9. The heat recovery method for the outdoor air conditioning unit as described in claim 8, comprising: When the first enthalpy value is less than the second enthalpy value, the connection between the first heating coil and the second heating coil is disconnected.

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