To add a bit to the earlier answers regarding enthalpy.

Enthalpy accounts for the energy associated with mass flow in/out of an open thermodynamic system.

The specific enthalpy $h$ (enthalpy per unit mass) is $h = u + pv$ where $u$ is specific internal energy, $p$ is pressure, and $v$ is specific volume. In the energy balance for the open system, the energy added to/removed form the system by mass flow is accounted for considering the enthalpy in/out of the system. The $pv$ term is called flow energy from an Eulerian viewpoint-fixed in space- as is used for an open thermodynamic system. (From a Lagrangian viewpoint- following a fixed mass- $pv$ is called flow work.)

In general the specific energy associated with mass flow is $h + V^2/2 + gZ$ where $V$ is velocity $g$ is the acceleration of gravity, and $Z$ is elevation. This accounts the kinetic and potential energy per unit mass for mass flowing in/out of an open thermodynamic system in in addition to the enthalpy.

For a closed thermodynamic system (no mass flow in/out) enthalpy is associated with a constant pressure process. For a closed system to which heat is added at constant pressure $Q = \Delta H$. $Q$ is heat added, $H$ is the enthalpy of the system equal to $U + p$V where $U$ is internal energy, $p$ is pressure, and V is volume. $\Delta H$ is the change in the enthalpy of the closed system.

To add a bit to the earlier answers regarding enthalpy.

Enthalpy accounts for the energy associated with mass flow in/out of an open thermodynamic system.

The specific enthalpy $h$ (enthalpy per unit mass) is $h = u + pv$ where $u$ is specific internal energy, $p$ is pressure, and $v$ is specific volume. In the energy balance for the open system, the energy added to/removed form the system by mass flow is accounted for considering the enthalpy in/out of the system. The $pv$ term is called flow energy from an Eulerian viewpoint-fixed in space- as is used for an open thermodynamic system. (From a Lagrangian viewpoint- following a fixed mass- $pv$ is called flow work.)

In general the specific energy associated with mass flow is $h + V^2/2 + gZ$ where $V$ is velocity $g$ is the acceleration of gravity, and $Z$ is elevation. This accounts the kinetic and potential energy per unit mass for mass flowing in/out of an open thermodynamic system in in addition to the enthalpy.

For a closed thermodynamic system (no mass flow in/out) enthalpy is associated with a constant pressure process. For a closed system $Q - W = \Delta U$ where $Q$ is heat added to the system, $W$ is work done by the system, and $\Delta U$ is change in internal energy, $U$, of the system. For the case where heat is slowly added at constant pressure, the work done by the system is $p \Delta $V and for constant pressure this is $\Delta (p$V$)$. Therefore, $Q = \Delta H$. $H$ is the enthalpy of the system equal to $U + p$V where , $p$ is pressure, and V is volume. $\Delta H$ is the change in the enthalpy of the closed system.

I suggest you consult a good text on Thermodynamics, such as one by Sonntag and Van Wylen.

Enthalpy accounts for the energy associated with mass flow in/out of an open thermodynamic system.

The specific enthalpy $h$ (enthalpy per unit mass) is $h = u + pv$ where $u$ is specific internal energy, $p$ is pressure, and $v$ is specific volume. In the energy balance for the open system, the energy added to/removed form the system by mass flow is accounted for considering the enthalpy in/out of the system. The $pv$ term is called flow energy from an Eulerian viewpoint-fixed in space- as is used for an open thermodynamic system. (From a Lagrangian viewpoint- following a fixed mass- $pv$ is called flow work.)

In general the specific energy associated with mass flow is $h + V^2/2 + gZ$ where $V$ is velocity $g$ is the acceleration of gravity, and $Z$ is elevation. This accounts the kinetic and potential energy per unit mass for mass flowing in/out of an open thermodynamic system in in addition to the enthalpy.

To add a bit to the earlier answers regarding enthalpy.

Enthalpy accounts for the energy associated with mass flow in/out of an open thermodynamic system.

The specific enthalpy $h$ (enthalpy per unit mass) is $h = u + pv$ where $u$ is specific internal energy, $p$ is pressure, and $v$ is specific volume. In the energy balance for the open system, the energy added to/removed form the system by mass flow is accounted for considering the enthalpy in/out of the system. The $pv$ term is called flow energy from an Eulerian viewpoint-fixed in space- as is used for an open thermodynamic system. (From a Lagrangian viewpoint- following a fixed mass- $pv$ is called flow work.)

In general the specific energy associated with mass flow is $h + V^2/2 + gZ$ where $V$ is velocity $g$ is the acceleration of gravity, and $Z$ is elevation. This accounts the kinetic and potential energy per unit mass for mass flowing in/out of an open thermodynamic system in in addition to the enthalpy.

For a closed thermodynamic system (no mass flow in/out) enthalpy is associated with a constant pressure process. For a closed system to which heat is added at constant pressure $Q = \Delta H$. $Q$ is heat added, $H$ is the enthalpy of the system equal to $U + p$V where $U$ is internal energy, $p$ is pressure, and V is volume. $\Delta H$ is the change in the enthalpy of the closed system.