Patent Description:
In heat transfer systems, a condenser is a device used to condense a substance from its gaseous to its liquid state through a cooling process. In so doing, the latent heat that is given up by the substance is transferred through the condenser to a surrounding environment. Condensers can be made according to numerous designs, and come in many sizes ranging from rather small (hand-held) to very large (industrial-scale units used in plant processes).

In some cases, a condensing process employed by a condenser can be divided into two segments. The two segments are circuited in series on a refrigerant stream and in parallel on a secondary fluid stream. The first segment is used to decrease refrigerant temperatures down to a saturated temperature level. The second segment is used to condense and sub-cool the refrigerant.

<CIT> discloses a heat pump installation comprising a compressor, a valve, a desuperheater and a condenser which are disposed in sequence to each other between the compressor and the valve, and an evaporator interposed between the valve and the compressor. A refrigerant flows from the compressor through the desuperheater and then through the condenser, and flows of water enter in parallel into the condenser and the desuperheater, respectively.

According to an aspect of the invention, a heat exchanger system is provided according to claim <NUM>. The present invention provides also a heat exchanger system according to claim <NUM>.

As will be described below, a secondary fluid stream flow of a condenser is divided to feed a first segment and a second segment with a calculated and controlled split ratio. The split ratio can be set to optimize heat transfer efficiency and output water temperatures. The first and second segments are parts of a single heat exchanger with a circuiting architecture or two separate heat exchangers. In both cases, de-superheating and condensing processes are separated and thus make better use of heat transfer surfaces.

With reference to <FIG>, a heat exchanger system <NUM> is provided. The heat exchanger system <NUM> includes a compressor <NUM>, an expansion valve <NUM>, a condenser <NUM> fluidly interposed between the compressor <NUM> and the expansion valve <NUM> and an evaporator <NUM> fluidly interposed between the expansion valve <NUM> and the compressor <NUM>. The compressor <NUM> is operable to compress a saturated vapor therein and to output a highpressure and high-temperature superheated vapor toward the condenser <NUM>. The condenser <NUM> causes the superheated vapor received from the compressor <NUM> to condense through thermal transfer with water, for example. The condenser <NUM> outputs the resulting condensed liquid toward the expansion valve <NUM> as a saturated liquid. The expansion valve <NUM> abruptly reduced a pressure of the saturated liquid and produces a relatively cold mixture. The liquid of this cold mixture is then evaporated in the evaporator <NUM> and the resulting saturated vapor is returned to the compressor <NUM>.

With continued reference to <FIG> and with additional reference to <FIG>, the condenser <NUM> includes a first or de-superheating segment <NUM> and a second or condensing segment <NUM>. The de-superheating segment <NUM> and the condensing segment <NUM> are separate from one another. During operations of the condenser <NUM>, the condensing segment <NUM> receives a first liquid, such as refrigerant being passed or cycled through the heat exchanger system <NUM>, downstream from the de-superheating segment <NUM>. As such, the de-superheating segment <NUM> and the condensing segment <NUM> are disposed in series with respect to the first liquid. While the operations proceed, the de-superheating segment <NUM> and the condensing segment <NUM> are also receptive of a second liquid, such as water, in parallel. At least the flows of the second liquid into the de-superheating segment <NUM> are controllable based on characteristics of flows of the second liquid exiting the de-superheating segment <NUM>.

As shown in <FIG> the condenser <NUM> may also include a first circuit <NUM> (see <FIG>) that traverses the de-superheating segment <NUM> and the condensing segment <NUM> with a serial arrangement as well as a second circuit <NUM> (see <FIG>) that traverses the de-superheating segment <NUM> and the condensing segment <NUM> with a parallel arrangement.

As shown in <FIG> and <FIG>, the first circuit <NUM> is formed of a first header <NUM>, which includes a first inlet <NUM> and a first outlet <NUM>, a second header <NUM>, a separation plate <NUM> and first and second passes <NUM> and <NUM> fluidly connecting the first header <NUM> and the second header <NUM>. The first inlet <NUM> is receptive of the first liquid from the compressor <NUM> and the outlet <NUM> is disposed to permit the first liquid to exit toward the expansion valve <NUM>. The separation plate <NUM> is disposed in the first header <NUM> proximate to the first inlet <NUM> and defines the first passes <NUM> as the de-superheating segment <NUM> and the second passes <NUM> as the condensing segment <NUM>. That is, the first liquid enters the first header <NUM> of the condenser <NUM> via the first inlet <NUM> and is forced to flow through the first passes <NUM> toward the second header <NUM> by the separation plate <NUM>. The first liquid then flows from the second header <NUM>, through the second passes <NUM> and back toward the first header <NUM> whereupon the first liquid exits the condenser <NUM> via the first outlet <NUM>.

As shown in <FIG> and <FIG>, the second circuit <NUM> is formed of a first header <NUM>, which includes a first inlet <NUM> and a second inlet <NUM>, a second header <NUM>, which includes a first outlet <NUM> and a second outlet <NUM> (the first and second outlets <NUM> and <NUM> may be superimposed on another or separate from one another), a separation plate <NUM> and first and second passes <NUM> and <NUM> fluidly connecting the first header <NUM> and the second header <NUM>. The first and second inlets <NUM> and <NUM> are receptive of the second liquid in parallel and the second liquid exits through the first and second outlets <NUM> and <NUM> in parallel. The separation plate <NUM> is disposed at least in the first header <NUM> proximate to the first inlet <NUM> and defines the first passes <NUM> as the de-superheating segment <NUM> and the second passes <NUM> as the condensing segment <NUM>. That is, the second liquid enters the first header <NUM> of the condenser <NUM> via the first and second inlets <NUM> and <NUM> and is forced to flow through the first and second passes <NUM> and <NUM> in parallel toward the second header <NUM> by the separation plate <NUM>. The second liquid then flows out of the second header <NUM> via the first and second outlets <NUM> and <NUM>.

As shown in <FIG>, the heat exchanger system <NUM> further includes a flow splitter <NUM>, a flow mixer <NUM>, a sensor <NUM> and a controllable valve <NUM>.

The flow splitter <NUM> is disposed upstream from the de-superheating segment <NUM> and the condensing segment <NUM> and is disposed and configured to split a flow of the second liquid into first and second parallel flows of the second liquid <NUM> and <NUM> for respective entry the de-superheating segment <NUM> and the condensing segment <NUM> in parallel. The flow mixer <NUM> is disposed downstream from the de-superheating segment <NUM> and the condensing segment <NUM> and is disposed and configured to mix third and fourth parallel flows of the second liquid <NUM> and <NUM> respectively exiting the de-superheating segment <NUM> and the condensing segment <NUM> in parallel.

The sensor <NUM> may be provided as a single sensor <NUM> that is interposed between the de-superheating segment <NUM> and the flow mixer <NUM> such that the single sensor <NUM> is disposed to measure the characteristics of the third flow of the second liquid <NUM> exiting the de-superheating segment <NUM>. In accordance with embodiments, the single sensor <NUM> may include or be provided as a temperature sensor. The controllable valve <NUM> is interposed between the flow splitter <NUM> and the de-superheating segment <NUM> and is controllable to adjust an amount of the first flow of the second liquid <NUM> entering the de-superheating segment <NUM> based on readings (e.g., temperature readings of the flows of the third flow of the second liquid <NUM> exiting the de-superheating segment <NUM>) of the sensor <NUM>. The controllable valve <NUM> may include or be provided at least as a controllable bi-directional valve or a two-way valve controllable <NUM>.

With reference to <FIG> and in accordance with alternative embodiments, the sensor <NUM> is provided as first sensors <NUM> and <NUM> and as a second sensor <NUM>. The first sensors <NUM> and <NUM> are interposed between the flow mixer <NUM> and each of the de-superheating segment <NUM> and the condensing segment <NUM> such that the first sensors <NUM> and <NUM> are disposed to measure the characteristics of the third and fourth flows of the second liquid <NUM> and <NUM> exiting the de-superheating segment <NUM> and the condensing segment <NUM>, respectively. The second sensor <NUM> is disposed upstream of the de-superheating segment <NUM> such that the second sensor <NUM> is disposed to measure characteristics of flows of the first liquid entering the de-superheating segment <NUM> on the first circuit <NUM>. In accordance with embodiments, the first sensors <NUM> and <NUM> and the second sensor <NUM> may each include or be provided as temperature sensors. The controllable valve <NUM> is interposed between the flow splitter <NUM> and each of the de-superheating segment <NUM> and the condensing segment <NUM> and is controllable to adjust an amount of the first and second flows of the second liquid <NUM> and <NUM> entering the de-superheating segment <NUM> and the condensing segment <NUM> based on readings (e.g., temperature readings of the flows of the third and fourth flows of the second liquid <NUM> and <NUM> exiting the de-superheating segment <NUM> and the condensing segment <NUM> and temperature readings of the flows of the first liquid into the de-superheating segment <NUM>) of the first sensors <NUM> and <NUM> and of the second sensor <NUM>. The controllable valve <NUM> may include or be provided at least as a controllable multi-directional valve or as a three-way controllable valve <NUM>.

With reference to <FIG>, the heat exchanger system <NUM> of <FIG> and <FIG> may also include a controller <NUM>. As shown in <FIG>, the controller <NUM> includes a processing unit <NUM>, a memory unit <NUM>, a networking unit <NUM> and a servo control unit <NUM>. The processing unit <NUM> is receptive of readings from the single sensor <NUM> (see <FIG>) or from the first sensors <NUM> and <NUM> and the second sensor <NUM> (see <FIG>) by way of the networking unit <NUM>. The processing unit <NUM> also controls operations of the bi-directional or two-way controllable valve <NUM> (see <FIG>) or the multi-directional or three-way controllable valve <NUM> (see <FIG>) by way of the servo control unit <NUM>. The memory unit <NUM> has executable instructions stored thereon, which are readable and executable by the processing unit <NUM>. When the executable instructions are read and executed by the processing unit <NUM>, the executable instructions cause the processing unit <NUM> to analyze the readings received by way of the networking unit <NUM> and to control the operations of the bi-directional or two-way controllable valve <NUM> or the multi-directional or three-way controllable valve <NUM> based on results of that analysis.

For example, for the heat exchanger system <NUM> of <FIG>, in an event that the temperature of the third flow of the second liquid <NUM> is deemed too low or too high by the processing unit <NUM>, the processing unit <NUM> could instruct the servo control unit <NUM> to open or close the bi-directional or two-way controllable valve <NUM> to increase or decrease a magnitude of the first flow of the second liquid <NUM>.

As another example, for the heat exchanger system <NUM> of <FIG>, in an event that the temperatures of the third and fourth flows of the second liquid <NUM> and <NUM> are deemed too low/high or too high/low by the processing unit <NUM>, the processing unit <NUM> could instruct the servo control unit <NUM> to operate the multi-directional or three-way controllable valve <NUM> to increase or decrease (or vice versa) relative magnitudes of the first and second flows of the second liquid <NUM> and <NUM>.

With reference to <FIG>, a method of operating a heat exchanger, such as the condenser <NUM> described above, is provided. As shown in <FIG>, the method includes directing a first liquid through first and second segments in series (block <NUM>), directing a second liquid through the first and second segments in parallel, respectively (block <NUM>), measuring characteristics of at least flows of the second liquid exiting the first segment (block <NUM>) and controlling at least an amount of the second liquid permitted to enter the first segment based on readings derived from the measuring (block <NUM>).

Claim 1:
A heat exchanger system (<NUM>), comprising:
a vapor-compression circuit comprising a compressor (<NUM>), an expansion valve (<NUM>), a condenser (<NUM>) fluidly interposed between the compressor (<NUM>) and the expansion valve (<NUM>) and an evaporator (<NUM>) fluidly interposed between the expansion valve (<NUM>) and the compressor (<NUM>), wherein the condenser (<NUM>) comprises a de-superheating segment (<NUM>) and a condensing segment (<NUM>),
the condensing segment (<NUM>) being receptive of a first liquid downstream from the de-superheating segment (<NUM>),
the condensing and de-superheating segments (<NUM>, <NUM>) being receptive of a second liquid in parallel, and
flows of the second liquid into the de-superheating segment (<NUM>) being controllable based on characteristics of flows of the second liquid exiting the de-superheating segment (<NUM>), and in that the heat exchanger system (<NUM>) further comprises
a flow splitter (<NUM>) for the second liquid disposed upstream from the de-superheating and condensing segments (<NUM>, <NUM>);
a flow mixer (<NUM>) for the second liquid disposed downstream from the de-superheating and condensing segments (<NUM>, <NUM>);
a sensor (<NUM>) interposed between the de-superheating segment (<NUM>) and the flow mixer (<NUM>) to measure the characteristics of the flows of the second liquid; and
a controllable valve (<NUM>) interposed between the flow splitter (<NUM>) and the de-superheating segment (<NUM>), the controllable valve (<NUM>) being controllable to adjust an amount of the second liquid entering the de-superheating segment (<NUM>) based on readings of the sensor (<NUM>).