JP7068861B2 - Chiller system - Google Patents

Description

The present invention compresses a first heat medium circulation path that circulates a first heat medium that supplies hot or cold heat in a heat demand section, a refrigerant circulation path that circulates a refrigerant, and a refrigerant that circulates in the refrigerant circulation path. The present invention relates to a chiller system including an engine-driven compressor and a GHP chiller that controls the temperature of the first heat medium in a form of heating or cooling the first heat medium by the heat of condensation or evaporation of the refrigerant.

Conventionally, as shown in Patent Document 1, a chiller system including a GHP chiller used for heating / cooling an object of a heat demand unit is known.
The chiller system shown in Patent Document 1 is compressed by an engine-driven compressor that compresses the refrigerant circulating in the refrigerant circulation path, an expansion valve that expands the refrigerant circulating in the refrigerant circulation path, and an engine-driven compressor. A first heat medium that works as a heater that heats the first heat medium such as water with the heat of condensation of the generated refrigerant, or as a cooler that cools the first heat medium with the heat of evaporation of the refrigerant expanded by the expansion valve. A heat exchanger is provided with a condenser that condenses the refrigerant using a second heat medium such as air as a heat dissipation source, or a second heat medium heat exchanger that acts as an evaporator that evaporates the refrigerant using the second heat medium as a heat absorption source. It is composed of.
The chiller system is a GHP chiller equipped with an engine as a drive source, and the GHP chiller has an advantage that it can be operated with high efficiency when a load is large, and also executes a heating operation for heating a first heat medium. In this case, there is also an advantage that efficiency can be improved by using waste heat.

Japanese Unexamined Patent Publication No. 2014-052122

In the GHP chiller disclosed in Patent Document 1, when the load is small during the heating operation for heating the first heat medium or the cooling operation for cooling the first heat medium, the circulation amount of the refrigerant in the refrigerant circulation path is determined. In order to reduce it, the rotation speed of the engine-driven compressor will be reduced. However, in the case of an engine-driven compressor, since the lower limit of the rotation speed is relatively high, the load cannot be sufficiently reduced while the compressor is maintained in rotation. Therefore, for example, when the load becomes 30% or less, the operating load is reduced in the form of ON / OFF control of the engine-driven compressor.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a chiller system capable of alleviating a decrease in efficiency even at a low load.

The chiller system to achieve the above purpose is
Engine-driven compression that compresses the first heat medium circulation path that circulates the first heat medium that supplies hot or cold heat in the heat demand section, the refrigerant circulation path that circulates the refrigerant, and the refrigerant that circulates in the refrigerant circulation path. It is a chiller system equipped with a GHP chiller that controls the temperature of the first heat medium in the form of heating or cooling the first heat medium by the heat of condensation or evaporation of the refrigerant.
An EHP that has an electrically driven compressor that compresses the refrigerant that circulates in the refrigerant circulation path, and controls the temperature of the first heat medium in the form of heating or cooling the first heat medium by the heat of condensation or evaporation of the refrigerant. Equipped with a chiller
The GHP chiller includes a GHP first heat medium heat exchanger that heats or cools the first heat medium by the heat of condensation or evaporation of the refrigerant, and the refrigerant circulation path that circulates the refrigerant in the GHP first heat medium heat exchanger. With a GHP refrigerant circulation path as
The EHP chiller includes an EHP first heat medium heat exchanger that heats or cools the first heat medium by the heat of condensation or evaporation of the refrigerant, and the refrigerant circulation path that circulates the refrigerant in the EHP first heat medium heat exchanger. Has an EHP refrigerant circulation path as
The GHP refrigerant circulation path and the EHP refrigerant circulation path are separately provided.
In the first heat medium circulation path, the EHP first heat medium heat exchanger and the GHP first heat medium heat exchanger are placed in the first heat medium flow direction when the heat demand unit is the starting point. The point is that they are provided in series in the order described from the upstream side .

According to the chiller system having the above characteristic configuration, in addition to the GHP chiller, it also has an EHP chiller that can be operated with relatively high efficiency even at a low load. Therefore, for example, at a low load, the operating capacity ratio of the EHP chiller can be determined. Control can be performed to gradually increase the operating capacity ratio of the GHP chiller as the load is increased and the load is increased from low load to high load.
This makes it possible to realize a chiller system that can maintain relatively high efficiency from low load to high load.
Further, in the heat demand unit to which the first heat medium heated or cooled by the chiller system is usually supplied, it is often desired to control the temperature with relatively high accuracy.
According to the above characteristic configuration, the EHP chiller heat exchanger and the GHP chiller heat exchanger are described from the upstream side in the first heat medium flow direction when the heat demand portion is the starting point in the first heat medium circulation path. For example, in the first heat medium circulation path, the temperature of the first heat medium at the outlet of the GHP first heat medium heat exchanger is controlled to the target temperature received by the input unit. While the temperature of the first heat medium is accurately controlled to a desired target temperature by a relatively simple control of controlling the temperature of the first heat medium at the outlet of the EHP first heat medium heat exchanger in the state of being present. , The operating capacity ratio between EHP and GHP can be appropriately controlled.
That is, by adopting such a relatively simple control, a configuration that does not form a control system that uniformly controls the operating capacity ratio of the GHP chiller and the EHP chiller, that is, the GHP that controls the operating capacity of the GHP chiller. Even in a configuration in which a control device and an EHP control device for controlling the operating capacity of the EHP chiller are separately provided, the temperature of the first heat medium is accurately controlled to a desired target temperature, and the EHP and GHP are combined. It is possible to realize a chiller system that can appropriately control the operating capacity ratio.
Further, as in the above-mentioned characteristic configuration, in the first heat medium circulation path, the EHP first heat medium heat exchanger and the GHP first heat medium heat exchanger are provided in series by adopting a configuration in which the EHP first heat medium heat exchanger is provided in parallel. Compared with the case of adopting the above, the valve body that controls the flow rate ratio of the first heat medium to the EHP first heat medium heat exchanger and the GHP first heat medium heat exchanger can be omitted, and the configuration can be simplified. Can be planned.

Further features of the chiller system are
A control device for executing operation capacity ratio control for controlling the operation capacity ratio of the GHP chiller and the operation capacity ratio of the EHP chiller with respect to the total operation capacity under the current load is provided.
The control device has a GHP first heat medium inlet temperature which is the temperature of the first heat medium at the inlet of the GHP first heat medium heat exchanger and a GHP first heat medium outlet temperature which is the temperature of the first heat medium at the outlet. The GHP first heat medium temperature difference, which is the temperature difference between the two, and the EHP first heat medium inlet temperature, which is the temperature of the first heat medium at the inlet of the EHP first heat medium heat exchanger, and the first heat medium at the outlet. The point is to execute the operation capacity ratio control in a form of changing the temperature difference ratio, which is the ratio of the temperature difference from the EHP first heat medium outlet temperature, which is the temperature, to the EHP first heat medium temperature difference.

By adopting the above control, the operating capacity ratio between the EHP and the GHP can be controlled by a simpler control. Therefore, as a control device, an EHP control device for controlling the operating capacity of the EHP chiller is used. Even if the configuration is separately provided, it is possible to realize a chiller system capable of controlling the temperature of the first heat medium to a desired target temperature appropriately and accurately.

In the chiller system described so far,
In the operation capacity ratio control, the control device corresponds to the ratio between the operation capacity ratio of the GHP chiller and the operation capacity ratio of the EHP chiller, and corresponds to the temperature difference between the GHP first heat medium and the EHP first heat medium. It is preferable to control the ratio with the temperature difference.

Further features of the chiller system are
The control device includes the temperature of the first heat medium at the inlets of the GHP first heat medium heat exchanger and the EHP first heat medium heat exchanger, and the GHP first heat medium heat exchanger and the EHP first. When the refrigerant temperature difference, which is the temperature difference from the temperature of the refrigerant passing through the heat medium heat exchanger, exceeds the correction judgment temperature difference.
The point is to execute the refrigerant temperature correction control for controlling the temperature of the refrigerant passing through the GHP first heat medium heat exchanger and the EHP first heat medium heat exchanger so that the refrigerant temperature difference becomes small.

Hereinafter, the operation and effect of the above-mentioned feature configuration will be described with reference to FIG. 2 as an example of a case where a cooling operation is executed in a GHP chiller.
The action and effect are the same even in the case of the EHP chiller, and are the same even in the case of the heating operation.
In the chiller system, theoretically, when the cooling operation is performed in the GHP chiller when the flow rate of the refrigerant circulating in the refrigerant circulation path is constant, that is, the GHP first heat medium heat exchanger is the first. When working as a cooler for cooling the heat medium, the higher the refrigerant temperature (evaporation temperature) in the GHP 1st heat medium heat exchanger is set, the less the compression work in the compressor and the lower the input energy (W in FIG. 2). However, since the enthalpy (h in FIG. 2) in the evaporation process increases slightly (Δh in FIG. 2), the performance coefficient ((h + Δh) / (W−ΔW)) becomes high.
Therefore, in the above-mentioned characteristic configuration, the control device has the temperature of the first heat medium at the inlet of the GHP first heat medium heat exchanger and the GHP first heat medium heat exchange in order to improve the efficiency of the chiller system. Refrigerator temperature correction that raises the temperature of the refrigerant passing through the GHP first heat medium heat exchanger (evaporation temperature) so that the refrigerant temperature difference, which is the temperature difference from the temperature of the refrigerant passing through the vessel (evaporation temperature), becomes small. Take control.
However, in reality, when the evaporation temperature is increased in this way, the refrigerant temperature difference, which is the temperature difference between the temperature of the first heat medium and the temperature of the refrigerant in the GHP first heat medium heat exchanger, becomes small. The time required for heat exchange between the first heat medium and the refrigerant becomes long, and there is a risk that a sufficient amount of work cannot be secured.
Therefore, in the above-mentioned characteristic configuration, in the above-mentioned refrigerant temperature correction control, the temperature of the first heat medium at the inlet of the GHP first heat medium heat exchanger and the refrigerant passing through the GHP first heat medium heat exchanger are used. When the refrigerant temperature difference, which is the temperature difference from the temperature (evaporation temperature), exceeds the correction determination temperature difference (for example, the temperature difference of about 5 ° C. or higher and 6 ° C. or lower), the refrigerant temperature (evaporation temperature) is determined. Even if it is increased, when it is assumed that a sufficient work load can be secured in the GHP first heat medium heat exchanger, the temperature difference of the refrigerant is reduced (for example, a temperature difference of about 5 ° C. or higher and 6 ° C. or lower). Controls the temperature of the refrigerant passing through the GHP 1st heat medium heat exchanger, specifically, the valve opening of the expansion valve and the rotation speed and torque of the engine-driven compressor. To do.

Further features of the chiller system are
A control device for controlling the operating capacity ratio of the GHP chiller and the operating capacity ratio of the EHP chiller to the total operating capacity under the current load is provided.
The control device is configured to be able to acquire the target temperature of the first heat medium in the heat demand unit.
The control device executes a power demand prediction process for predicting a power demand in a facility where the heat demand unit is provided and power is supplied from an electric power company.
The EHP chiller so that the contracted power, which is the maximum value of the power consumption of the facility determined with the electric power company, does not exceed the power demand of the facility predicted by the power demand prediction process. Execute demand control to control the operating capacity ratio of
In the state of demand control, the first outlet of the GHP first heat medium heat exchanger is in the first heat medium flow direction when the heat demand unit is the starting point in the first heat medium circulation path. The point is to control the operating capacity ratio of the GHP chiller so that the temperature of the heat medium becomes the target temperature.

According to the above feature configuration, a configuration that does not form a control system that uniformly controls the operating capacity ratio of the GHP chiller and the EHP chiller, that is, the GHP control device that controls the operating capacity ratio of the GHP chiller and the operation of the EHP chiller. Even if the EHP control device for controlling the capacity ratio is separately provided, the operating capacity ratio between the EHP chiller and the GHP chiller can be appropriately controlled while controlling the power demand so as not to exceed the contracted power. The temperature of the first heat medium can be accurately controlled to a desired target temperature.

The chiller system described so far is
It is preferable that the GHP control device for controlling the operation of the GHP chiller and the EHP control device for controlling the operation of the EHP chiller are provided independently of each other.

In the chiller system described so far, the GHP control device and the EHP control device have appropriate operating capacities even if they are controlled independently of each other as long as they store a map of the operating capacity ratio for each load. It is possible to realize a hybrid chiller system of GHP and EHP that can accurately control the temperature of the first heat medium guided to the heat demand unit while maintaining the ratio.

Schematic block diagram of the chiller system according to the embodiment of the present invention Ph diagram to explain the effect of temperature difference correction control

The chiller system 100 according to the embodiment of the present invention relates to a system that can be operated with high efficiency even at a low load.
As shown in FIG. 1, the chiller system 100 includes a GHP chiller 30 and an EHP chiller 40 that are configured to be operated by receiving electric power from the electric power company De. The electric power company De supplies electric power to the facility where the chiller system 100 is installed.
The GHP chiller 30 is provided with a GHP control device 31 for controlling its operation, and the EHP chiller 40 is provided with an EHP control device 41 for controlling its operation. The GHP control device 31 and the EHP control device 41 are provided separately from each other independently of each other.
That is, in the chiller system 100 according to the embodiment, the operation control by the GHP control device 31 of the GHP chiller 30 and the operation control by the EHP control device 41 of the EHP chiller 40 are executed independently. The GHP control device 31 and the EHP control device 41 adopt a configuration in which they do not communicate with each other.

The GHP chiller 30 has a GHP refrigerant circulation path C1 as a refrigerant circulation path and an engine-driven compressor 35 for compressing the refrigerant circulating in the GHP refrigerant circulation path C1. 1 The temperature of the first heat medium is controlled in the form of heating or cooling the heat medium.
To add an explanation, as shown in FIG. 1, the GHP chiller 30 includes an engine-driven compressor 35 driven by the engine E, a GHP expansion valve 32 that expands the refrigerant circulating in the GHP refrigerant circulation path C1, and a GHP expansion valve 32. The GHP first heat medium heat exchanger 33 that heats or cools the first heat medium by the heat of condensation or evaporation of the refrigerant, and the GHP air heat exchanger that condenses or evaporates the refrigerant in the form of heat exchange between the refrigerant and the outdoor air. It is configured to include 36.
Further, the GHP refrigerant circulation path C1 is heated by passing the refrigerant in the order described in the engine drive type compressor 35, the GHP first heat medium heat exchanger 33, the GHP expansion valve 32, and the GHP air heat exchanger 36. A GHP four-way valve that switches between operation and cooling operation in which the refrigerant flows in the order described in the engine-driven compressor 35, the GHP air heat exchanger 36, the GHP expansion valve 32, and the GHP first heat medium heat exchanger 33. 34 is provided.

The EHP chiller 40 has an EHP refrigerant circulation path C2 as a refrigerant circulation path and an electrically driven compressor 45 for compressing the refrigerant circulating in the EHP refrigerant circulation path C2, and the EHP chiller 40 is the first due to the heat of condensation or evaporation of the refrigerant. 1 The temperature of the first heat medium is controlled in the form of heating or cooling the heat medium.
To add an explanation, as shown in FIG. 1, the EHP chiller 40 includes an electric drive type compressor 45 driven by a motor M, an EHP expansion valve 42 for expanding a refrigerant circulating in an EHP refrigerant circulation path C2, and an EHP expansion valve 42. The EHP first heat medium heat exchanger 43 that heats or cools the first heat medium by the heat of condensation or evaporation of the refrigerant, and the EHP air heat exchanger that condenses or evaporates the refrigerant in the form of heat exchange between the refrigerant and the outdoor air. It is configured to include 46.
Further, the EHP refrigerant circulation path C2 is heated by passing the refrigerant in the order described in the electric drive type compressor 45, the EHP first heat medium heat exchanger 43, the EHP expansion valve 42, and the EHP air heat exchanger 46. EHP four-way valve that switches between operation and cooling operation in which the refrigerant flows in the order described in the electric drive type compressor 45, the EHP air heat exchanger 46, the EHP expansion valve 42, and the EHP first heat medium heat exchanger 43. 44 is provided.

That is, the chiller system 100 according to the embodiment separately includes a GHP refrigerant circulation path C1 and an EHP refrigerant circulation path C2.

In the chiller system 100, the heat demand unit 50 is provided with a first heat medium circulation path C3 that circulates a first heat medium such as water that supplies hot or cold heat, and the first heat medium circulation path C3 is provided. , A pressure feed pump P for pumping the first heat medium is provided, and the EHP first heat medium heat exchanger 43 and the GHP first heat medium are provided in the direction of flow of the first heat medium when the heat demand unit 50 is the starting point. The heat exchanger 33 is provided in series from the upstream side in the order described.
The heat demand unit 50 controls the rotation speed of the pump P from the target temperature set by the setting input unit (not shown) and the temperature of the first heat medium.

Further, in the first heat medium circulation path C3, the temperature of the first heat medium at the inlet of the EHP first heat medium heat exchanger 43 in the flow direction of the first heat medium when the heat demand unit 50 is the starting point. The outlets of the first temperature sensor S1 and the EHP first heat medium heat exchanger 43 (GHP first heat medium heat exchanger 43) for measuring (the temperature between the heat demand unit 50 and the EHP first heat medium heat exchanger 43). Second temperature sensor S2 for measuring the temperature of the first heat medium at the inlet of 33), the temperature of the first heat medium at the outlet of the GHP first heat medium heat exchanger 33 (GHP first heat medium heat exchanger 33 and heat) It is provided with a third temperature sensor S3 that measures the temperature between the demand unit 50 and the heat unit 50. Further, a flow rate sensor S4 for measuring the flow rate of the first heat medium passing through the first heat medium circulation path C3 is provided.
In each of the GHP control device 31 and the EHP control device 41, the target temperature of the first heat medium input by the setting input unit (not shown) of the heat demand unit 50 and the temperature measured by the first temperature sensor S1. , The temperature measured by the second temperature sensor S2, the temperature measured by the third temperature sensor S3, and the flow rate measured by the flow rate sensor S4 are configured to be receivable.

As described above, the chiller system 100 according to the embodiment employs a simple configuration in which the GHP control device 31 and the EHP control device 41 are separately provided and do not communicate with each other. Even in such a configuration, a configuration is adopted in which the operating capacity ratios of the GHP chiller 30 and the EHP chiller 40 are appropriately controlled based on the heating / cooling load in the heat demand unit 50.
In other words, the GHP control device 31 and the EHP control device 41 are configured to be able to execute the operation capacity ratio control that controls the operation capacity ratio of the GHP chiller 30 and the operation capacity ratio of the EHP chiller 40 with respect to the total operation amount under the current load. ing.

Adding an explanation, the GHP control device 31 and the EHP control device 41 each have a temperature difference between the target temperature set by the setting input unit of the heat demand unit 50 and the temperature measured by the first temperature sensor S1. , The flow rate measured by the flow rate sensor S4 is integrated to derive the required load in the heat demand unit 50.
Each of the GHP control device 31 and the EHP control device 41 stores an operation control map showing the relationship of its own operation capacity ratio in each load, and the operation control map shows its own operation capacity ratio in the above-derived derived load. Call from.
Each of the GHP control device 31 and the EHP control device 41 is measured by the GHP first heat medium inlet temperature (measured by the second temperature sensor S2), which is the temperature of the first heat medium at the inlet of the GHP first heat medium heat exchanger 33. GHP first heat medium temperature difference, which is the temperature difference between GHP first heat medium outlet temperature (temperature measured by the third temperature sensor S3), which is the temperature of the first heat medium at the outlet, and EHP. EHP first heat medium inlet temperature (temperature measured by the first temperature sensor S1) which is the temperature of the first heat medium at the inlet of the first heat medium heat exchanger 43 and the temperature of the first heat medium at the outlet. The operating capacity ratio control is executed in a form of changing the ratio of the temperature difference from the EHP first heat medium outlet temperature (the temperature measured by the second temperature sensor S2) to the EHP first heat medium temperature difference.
Specifically, each of the GHP control device 31 and the EHP control device 41 corresponds to the ratio between the operating capacity ratio of the GHP chiller 30 and the operating capacity ratio of the EHP chiller 40 in the operating capacity ratio control, and the GHP first. The ratio between the heat medium temperature difference and the EHP first heat medium temperature difference is controlled.
In the embodiment, each of the GHP control device 31 and the EHP control device 41 sets the ratio of the operating capacity ratio of the GHP chiller 30 to the operating capacity ratio of the EHP chiller 40 in the operating capacity ratio control as the GHP first heat medium. Control is performed to match the ratio between the temperature difference and the temperature difference of the EHP first heat medium.

Normally, in the chiller system 100, it is necessary to satisfy the target temperature required by the heat demand unit 50 with relatively high accuracy. However, according to the above-mentioned feature configuration, the GHP chiller 30 is the GHP first heat medium heat exchange. Since simple control for controlling the outlet temperature of the vessel 33 to the target temperature of the first heat medium is executed, the first heat medium guided to the heat demand unit 50 can be controlled to the target temperature with relatively high accuracy. Further, the GHP chiller 30 and the EHP chiller 40 each have a temperature difference of the first heat medium before and after passing through the GHP first heat medium heat exchanger 33, and before and after passing through the EHP first heat medium heat exchanger 43. The operating capacity ratio can be controlled to a desired value by a relatively simple control of adjusting the ratio with the temperature difference of the first heat medium to the operating capacity ratio.

Here, the electric power supplied from the electric power company De is configured to be supplied to each electric power load of the facility by the electric power line D. The actual received power received by the facility from the electric power company De via the power line D is measured by using the received power measuring unit 10.
The chiller system 100 according to the embodiment is configured to be able to execute demand control as well.
Specifically, the EHP control device 41 determines the power demand in the facility (not shown) in which the heat demand unit 50 that receives power from the electric power company De is provided, based on the measurement result of the power received power measuring unit 10. The power demand of the facility predicted by the power demand prediction process exceeds the contracted power, which is the maximum value of the power consumption of the facility determined with the electric power company De by executing the predicted power demand prediction process. Demand control for controlling the operating capacity ratio of the EHP chiller 40 is executed so as not to be present.
Further, the GHP control device 31 is in a state where the EHP control device 41 is demand-controlled, and the GHP control device 31 is the GHP first in the first heat medium flow direction when the heat demand unit 50 is the starting point in the first heat medium circulation path C3. 1 The operating capacity ratio of the GHP chiller 30 is controlled so that the temperature of the first heat medium at the outlet of the heat exchanger 33 (the temperature measured by the third temperature sensor S3) becomes the target temperature.

Even if the GHP control device 31 that controls the operating capacity ratio of the GHP chiller 30 and the EHP control device 41 that controls the operating capacity ratio of the EHP chiller 40 are separately provided by the control, the power demand is the contract power. The operating capacity ratio between the GHP chiller 30 and the EHP chiller 40 can be appropriately controlled while controlling so as not to exceed the above, and the temperature of the first heat medium can be accurately controlled to a desired target temperature.

[Another Embodiment]
(1) In the above embodiment, the configuration example in which the GHP control device 31 and the EHP control device 41 are provided independently of each other and in a state of not communicating with each other is shown.
However, the GHP control device 31 and the EHP control device 41 may be configured as an integrated control device. Alternatively, it may be provided in a state of communicating with each other.

(2) In the above embodiment, each of the GHP control device 31 and the EHP control device 41 controls the operating capacity ratio by changing the ratio between the GHP first heat medium temperature difference and the EHP first heat medium temperature difference. An example to execute is shown.
The temperature difference may be corrected as follows.
Incidentally, in the following, in order to simplify the explanation, a case where the cooling operation is executed by the GHP chiller 30 will be described as an example, but the same logic is established in the EHP chiller 40, and the same logic is also established in the heating operation. Is established.
In the GHP chiller 30, theoretically, as shown in FIG. 2, when the cooling operation is executed in the GHP chiller 30 when the refrigerant flow rate circulating in the GHP refrigerant circulation path C1 is constant, that is, the GHP. When the first heat medium heat exchanger 33 acts as a cooler for cooling the first heat medium, the higher the refrigerant temperature (evaporation temperature) in the GHP first heat medium heat exchanger 33 is set, the more the engine-driven compressor The compression work (W in FIG. 2) in 35 decreases, but the amount of change in enthalpy (h in FIG. 2) during the evaporation process of the refrigerant increases slightly (Δh in FIG. 2), so that the performance coefficient ((h + Δh) / ( W-ΔW)) becomes higher.
Therefore, in the above-mentioned characteristic configuration, the GHP control device 31 measures the temperature of the first heat medium at the inlet of the GHP first heat medium heat exchanger 33 (second temperature sensor) in order to improve the efficiency of the chiller system 100. GHP first heat medium heat exchange so that the refrigerant temperature difference, which is the temperature difference between the temperature measured in S2) and the temperature of the refrigerant passing through the GHP first heat medium heat exchanger 33 (evaporation temperature), becomes small. The refrigerant temperature correction control is performed to raise the temperature (evaporation temperature) of the refrigerant passing through the vessel 33.
However, in reality, when the evaporation temperature (evaporation temperature) is increased in this way, the refrigerant temperature difference is the temperature difference between the temperature of the first heat medium and the temperature of the refrigerant in the GHP first heat medium heat exchanger 33. Therefore, the time required for heat exchange between the first heat medium and the refrigerant becomes long, and there is a possibility that a sufficient amount of work cannot be secured.
Therefore, in the above-mentioned refrigerant temperature correction control, the temperature of the first heat medium at the inlet of the GHP first heat medium heat exchanger 33 and the temperature of the refrigerant passing through the GHP first heat medium heat exchanger 33 (evaporation temperature). Even if the refrigerant temperature difference, which is the temperature difference of the above, exceeds the correction determination temperature difference (for example, the temperature difference of about 5 ° C. or higher and 6 ° C. or lower) and the refrigerant temperature (evaporation temperature) is increased. When it is assumed that a sufficient amount of work can be secured in the GHP first heat medium heat exchanger 33, the temperature difference of the refrigerant is reduced (for example, the temperature difference is reduced to about 5 ° C. or higher and 6 ° C. or lower). ), Controls the temperature of the refrigerant passing through the GHP first heat medium heat exchanger 33, specifically, controls the valve opening degree of the GHP expansion valve 32 and the rotation speed and torque of the engine-driven compressor 35. It is.

( 3 ) In the above embodiment, the GHP control device 31 and the EHP control device 41 acquire the flow rate of the first heat medium passing through the first heat medium circulation path C3 in the form of receiving the measurement result of the flow rate sensor S4. An example of the configuration to be used is shown.
However, as another example, the GHP control device 31 and the EHP control device 41 derive the flow rate of the first heat medium flowing through the first heat medium circulation path C3 from the calculation based on the rotation speed of the pressure feed pump P. You may adopt the configuration to be acquired.

It should be noted that the configuration disclosed in the above embodiment (including another embodiment, the same shall apply hereinafter) can be applied in combination with the configuration disclosed in other embodiments as long as there is no contradiction. The embodiments disclosed in the present specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.

The chiller system of the present invention can be effectively used as a chiller system capable of alleviating a decrease in efficiency even at a low load.

30: GHP chiller 31: GHP control device 33: GHP first heat medium heat exchanger 35: engine-driven compressor 40: EHP chiller 41: EHP control device 43: EHP first heat medium heat exchanger 45: electric drive type Compressor 50: Heat demand unit 100: Chiller system C1: GHP refrigerant circulation path C2: EHP refrigerant circulation path C3: First heat medium circulation path E: Engine

Claims (6)

Engine-driven compression that compresses the first heat medium circulation path that circulates the first heat medium that supplies hot or cold heat in the heat demand section, the refrigerant circulation path that circulates the refrigerant, and the refrigerant that circulates in the refrigerant circulation path. A chiller system including a GHP chiller that controls the temperature of the first heat medium in the form of heating or cooling the first heat medium by the heat of condensation or evaporation of the refrigerant.
An EHP that has an electrically driven compressor that compresses the refrigerant that circulates in the refrigerant circulation path, and controls the temperature of the first heat medium in the form of heating or cooling the first heat medium by the heat of condensation or evaporation of the refrigerant. Equipped with a chiller
The GHP chiller includes a GHP first heat medium heat exchanger that heats or cools the first heat medium by the heat of condensation or evaporation of the refrigerant, and the refrigerant circulation path that circulates the refrigerant in the GHP first heat medium heat exchanger. With a GHP refrigerant circulation path as
The EHP chiller includes an EHP first heat medium heat exchanger that heats or cools the first heat medium by the heat of condensation or evaporation of the refrigerant, and the refrigerant circulation path that circulates the refrigerant in the EHP first heat medium heat exchanger. Has an EHP refrigerant circulation path as
The GHP refrigerant circulation path and the EHP refrigerant circulation path are separately provided.
In the first heat medium circulation path, the EHP first heat medium heat exchanger and the GHP first heat medium heat exchanger are placed in the first heat medium flow direction when the heat demand unit is the starting point. A chiller system installed in series in the order described from the upstream side . A control device for executing operation capacity ratio control for controlling the operation capacity ratio of the GHP chiller and the operation capacity ratio of the EHP chiller with respect to the total operation capacity under the current load is provided.
The control device has a GHP first heat medium inlet temperature which is the temperature of the first heat medium at the inlet of the GHP first heat medium heat exchanger and a GHP first heat medium outlet temperature which is the temperature of the first heat medium at the outlet. The GHP first heat medium temperature difference, which is the temperature difference between the two, and the EHP first heat medium inlet temperature, which is the temperature of the first heat medium at the inlet of the EHP first heat medium heat exchanger, and the first heat medium at the outlet. The first aspect of claim 1, wherein the operation capacity ratio control is executed in a form of changing the temperature difference ratio, which is the ratio of the temperature difference from the EHP first heat medium outlet temperature, which is the temperature, to the EHP first heat medium temperature difference. Chiller system . In the operation capacity ratio control, the control device corresponds to the ratio between the operation capacity ratio of the GHP chiller and the operation capacity ratio of the EHP chiller, and corresponds to the temperature difference between the GHP first heat medium and the EHP first heat medium. The chiller system according to claim 2, wherein the ratio to the temperature difference is controlled . The control device includes the temperature of the first heat medium at the inlets of the GHP first heat medium heat exchanger and the EHP first heat medium heat exchanger, and the GHP first heat medium heat exchanger and the EHP first. When the refrigerant temperature difference, which is the temperature difference from the temperature of the refrigerant passing through the heat medium heat exchanger, exceeds the correction judgment temperature difference.
Claim 2 or 3 for executing refrigerant temperature correction control for controlling the temperature of the refrigerant passing through the GHP first heat medium heat exchanger and the EHP first heat medium heat exchanger so that the refrigerant temperature difference becomes small. The chiller system described in . A control device for controlling the operating capacity ratio of the GHP chiller and the operating capacity ratio of the EHP chiller to the total operating capacity under the current load is provided.
The control device is configured to be able to acquire the target temperature of the first heat medium in the heat demand unit.
The control device executes a power demand prediction process for predicting a power demand in a facility where the heat demand unit is provided and power is supplied from an electric power company.
The EHP chiller so that the contracted power, which is the maximum value of the power consumption of the facility determined with the electric power company, does not exceed the power demand of the facility predicted by the power demand prediction process. Execute demand control to control the operating capacity ratio of
In the state of demand control, the first outlet of the GHP first heat medium heat exchanger is in the first heat medium flow direction when the heat demand unit is the starting point in the first heat medium circulation path. The chiller system according to any one of claims 1 to 4, wherein the operating capacity ratio of the GHP chiller is controlled so that the temperature of the heat medium becomes the target temperature . The chiller system according to any one of claims 1 to 5, further comprising a GHP control device for controlling the operation of the GHP chiller and an EHP control device for controlling the operation of the EHP chiller independently of each other. ..

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